| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ A T T R -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2006, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, USA. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Ada.Characters.Latin_1; use Ada.Characters.Latin_1; |
| |
| with Atree; use Atree; |
| with Checks; use Checks; |
| with Einfo; use Einfo; |
| with Errout; use Errout; |
| with Eval_Fat; |
| with Exp_Util; use Exp_Util; |
| with Expander; use Expander; |
| with Freeze; use Freeze; |
| with Lib; use Lib; |
| with Lib.Xref; use Lib.Xref; |
| with Namet; use Namet; |
| with Nlists; use Nlists; |
| with Nmake; use Nmake; |
| with Opt; use Opt; |
| with Restrict; use Restrict; |
| with Rident; use Rident; |
| with Rtsfind; use Rtsfind; |
| with Sdefault; use Sdefault; |
| with Sem; use Sem; |
| with Sem_Cat; use Sem_Cat; |
| with Sem_Ch6; use Sem_Ch6; |
| with Sem_Ch8; use Sem_Ch8; |
| with Sem_Dist; use Sem_Dist; |
| with Sem_Eval; use Sem_Eval; |
| with Sem_Res; use Sem_Res; |
| with Sem_Type; use Sem_Type; |
| with Sem_Util; use Sem_Util; |
| with Stand; use Stand; |
| with Sinfo; use Sinfo; |
| with Sinput; use Sinput; |
| with Stringt; use Stringt; |
| with Targparm; use Targparm; |
| with Ttypes; use Ttypes; |
| with Ttypef; use Ttypef; |
| with Tbuild; use Tbuild; |
| with Uintp; use Uintp; |
| with Urealp; use Urealp; |
| |
| package body Sem_Attr is |
| |
| True_Value : constant Uint := Uint_1; |
| False_Value : constant Uint := Uint_0; |
| -- Synonyms to be used when these constants are used as Boolean values |
| |
| Bad_Attribute : exception; |
| -- Exception raised if an error is detected during attribute processing, |
| -- used so that we can abandon the processing so we don't run into |
| -- trouble with cascaded errors. |
| |
| -- The following array is the list of attributes defined in the Ada 83 RM |
| |
| Attribute_83 : constant Attribute_Class_Array := Attribute_Class_Array'( |
| Attribute_Address | |
| Attribute_Aft | |
| Attribute_Alignment | |
| Attribute_Base | |
| Attribute_Callable | |
| Attribute_Constrained | |
| Attribute_Count | |
| Attribute_Delta | |
| Attribute_Digits | |
| Attribute_Emax | |
| Attribute_Epsilon | |
| Attribute_First | |
| Attribute_First_Bit | |
| Attribute_Fore | |
| Attribute_Image | |
| Attribute_Large | |
| Attribute_Last | |
| Attribute_Last_Bit | |
| Attribute_Leading_Part | |
| Attribute_Length | |
| Attribute_Machine_Emax | |
| Attribute_Machine_Emin | |
| Attribute_Machine_Mantissa | |
| Attribute_Machine_Overflows | |
| Attribute_Machine_Radix | |
| Attribute_Machine_Rounds | |
| Attribute_Mantissa | |
| Attribute_Pos | |
| Attribute_Position | |
| Attribute_Pred | |
| Attribute_Range | |
| Attribute_Safe_Emax | |
| Attribute_Safe_Large | |
| Attribute_Safe_Small | |
| Attribute_Size | |
| Attribute_Small | |
| Attribute_Storage_Size | |
| Attribute_Succ | |
| Attribute_Terminated | |
| Attribute_Val | |
| Attribute_Value | |
| Attribute_Width => True, |
| others => False); |
| |
| ----------------------- |
| -- Local_Subprograms -- |
| ----------------------- |
| |
| procedure Eval_Attribute (N : Node_Id); |
| -- Performs compile time evaluation of attributes where possible, leaving |
| -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately |
| -- set, and replacing the node with a literal node if the value can be |
| -- computed at compile time. All static attribute references are folded, |
| -- as well as a number of cases of non-static attributes that can always |
| -- be computed at compile time (e.g. floating-point model attributes that |
| -- are applied to non-static subtypes). Of course in such cases, the |
| -- Is_Static_Expression flag will not be set on the resulting literal. |
| -- Note that the only required action of this procedure is to catch the |
| -- static expression cases as described in the RM. Folding of other cases |
| -- is done where convenient, but some additional non-static folding is in |
| -- N_Expand_Attribute_Reference in cases where this is more convenient. |
| |
| function Is_Anonymous_Tagged_Base |
| (Anon : Entity_Id; |
| Typ : Entity_Id) |
| return Boolean; |
| -- For derived tagged types that constrain parent discriminants we build |
| -- an anonymous unconstrained base type. We need to recognize the relation |
| -- between the two when analyzing an access attribute for a constrained |
| -- component, before the full declaration for Typ has been analyzed, and |
| -- where therefore the prefix of the attribute does not match the enclosing |
| -- scope. |
| |
| ----------------------- |
| -- Analyze_Attribute -- |
| ----------------------- |
| |
| procedure Analyze_Attribute (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Aname : constant Name_Id := Attribute_Name (N); |
| P : constant Node_Id := Prefix (N); |
| Exprs : constant List_Id := Expressions (N); |
| Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname); |
| E1 : Node_Id; |
| E2 : Node_Id; |
| |
| P_Type : Entity_Id; |
| -- Type of prefix after analysis |
| |
| P_Base_Type : Entity_Id; |
| -- Base type of prefix after analysis |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Analyze_Access_Attribute; |
| -- Used for Access, Unchecked_Access, Unrestricted_Access attributes. |
| -- Internally, Id distinguishes which of the three cases is involved. |
| |
| procedure Check_Array_Or_Scalar_Type; |
| -- Common procedure used by First, Last, Range attribute to check |
| -- that the prefix is a constrained array or scalar type, or a name |
| -- of an array object, and that an argument appears only if appropriate |
| -- (i.e. only in the array case). |
| |
| procedure Check_Array_Type; |
| -- Common semantic checks for all array attributes. Checks that the |
| -- prefix is a constrained array type or the name of an array object. |
| -- The error message for non-arrays is specialized appropriately. |
| |
| procedure Check_Asm_Attribute; |
| -- Common semantic checks for Asm_Input and Asm_Output attributes |
| |
| procedure Check_Component; |
| -- Common processing for Bit_Position, First_Bit, Last_Bit, and |
| -- Position. Checks prefix is an appropriate selected component. |
| |
| procedure Check_Decimal_Fixed_Point_Type; |
| -- Check that prefix of attribute N is a decimal fixed-point type |
| |
| procedure Check_Dereference; |
| -- If the prefix of attribute is an object of an access type, then |
| -- introduce an explicit deference, and adjust P_Type accordingly. |
| |
| procedure Check_Discrete_Type; |
| -- Verify that prefix of attribute N is a discrete type |
| |
| procedure Check_E0; |
| -- Check that no attribute arguments are present |
| |
| procedure Check_Either_E0_Or_E1; |
| -- Check that there are zero or one attribute arguments present |
| |
| procedure Check_E1; |
| -- Check that exactly one attribute argument is present |
| |
| procedure Check_E2; |
| -- Check that two attribute arguments are present |
| |
| procedure Check_Enum_Image; |
| -- If the prefix type is an enumeration type, set all its literals |
| -- as referenced, since the image function could possibly end up |
| -- referencing any of the literals indirectly. |
| |
| procedure Check_Fixed_Point_Type; |
| -- Verify that prefix of attribute N is a fixed type |
| |
| procedure Check_Fixed_Point_Type_0; |
| -- Verify that prefix of attribute N is a fixed type and that |
| -- no attribute expressions are present |
| |
| procedure Check_Floating_Point_Type; |
| -- Verify that prefix of attribute N is a float type |
| |
| procedure Check_Floating_Point_Type_0; |
| -- Verify that prefix of attribute N is a float type and that |
| -- no attribute expressions are present |
| |
| procedure Check_Floating_Point_Type_1; |
| -- Verify that prefix of attribute N is a float type and that |
| -- exactly one attribute expression is present |
| |
| procedure Check_Floating_Point_Type_2; |
| -- Verify that prefix of attribute N is a float type and that |
| -- two attribute expressions are present |
| |
| procedure Legal_Formal_Attribute; |
| -- Common processing for attributes Definite, Has_Access_Values, |
| -- and Has_Discriminants |
| |
| procedure Check_Integer_Type; |
| -- Verify that prefix of attribute N is an integer type |
| |
| procedure Check_Library_Unit; |
| -- Verify that prefix of attribute N is a library unit |
| |
| procedure Check_Modular_Integer_Type; |
| -- Verify that prefix of attribute N is a modular integer type |
| |
| procedure Check_Not_Incomplete_Type; |
| -- Check that P (the prefix of the attribute) is not an incomplete |
| -- type or a private type for which no full view has been given. |
| |
| procedure Check_Object_Reference (P : Node_Id); |
| -- Check that P (the prefix of the attribute) is an object reference |
| |
| procedure Check_Program_Unit; |
| -- Verify that prefix of attribute N is a program unit |
| |
| procedure Check_Real_Type; |
| -- Verify that prefix of attribute N is fixed or float type |
| |
| procedure Check_Scalar_Type; |
| -- Verify that prefix of attribute N is a scalar type |
| |
| procedure Check_Standard_Prefix; |
| -- Verify that prefix of attribute N is package Standard |
| |
| procedure Check_Stream_Attribute (Nam : TSS_Name_Type); |
| -- Validity checking for stream attribute. Nam is the TSS name of the |
| -- corresponding possible defined attribute function (e.g. for the |
| -- Read attribute, Nam will be TSS_Stream_Read). |
| |
| procedure Check_Task_Prefix; |
| -- Verify that prefix of attribute N is a task or task type |
| |
| procedure Check_Type; |
| -- Verify that the prefix of attribute N is a type |
| |
| procedure Check_Unit_Name (Nod : Node_Id); |
| -- Check that Nod is of the form of a library unit name, i.e that |
| -- it is an identifier, or a selected component whose prefix is |
| -- itself of the form of a library unit name. Note that this is |
| -- quite different from Check_Program_Unit, since it only checks |
| -- the syntactic form of the name, not the semantic identity. This |
| -- is because it is used with attributes (Elab_Body, Elab_Spec, and |
| -- UET_Address) which can refer to non-visible unit. |
| |
| procedure Error_Attr (Msg : String; Error_Node : Node_Id); |
| pragma No_Return (Error_Attr); |
| procedure Error_Attr; |
| pragma No_Return (Error_Attr); |
| -- Posts error using Error_Msg_N at given node, sets type of attribute |
| -- node to Any_Type, and then raises Bad_Attribute to avoid any further |
| -- semantic processing. The message typically contains a % insertion |
| -- character which is replaced by the attribute name. The call with |
| -- no arguments is used when the caller has already generated the |
| -- required error messages. |
| |
| procedure Standard_Attribute (Val : Int); |
| -- Used to process attributes whose prefix is package Standard which |
| -- yield values of type Universal_Integer. The attribute reference |
| -- node is rewritten with an integer literal of the given value. |
| |
| procedure Unexpected_Argument (En : Node_Id); |
| -- Signal unexpected attribute argument (En is the argument) |
| |
| procedure Validate_Non_Static_Attribute_Function_Call; |
| -- Called when processing an attribute that is a function call to a |
| -- non-static function, i.e. an attribute function that either takes |
| -- non-scalar arguments or returns a non-scalar result. Verifies that |
| -- such a call does not appear in a preelaborable context. |
| |
| ------------------------------ |
| -- Analyze_Access_Attribute -- |
| ------------------------------ |
| |
| procedure Analyze_Access_Attribute is |
| Acc_Type : Entity_Id; |
| |
| Scop : Entity_Id; |
| Typ : Entity_Id; |
| |
| function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id; |
| -- Build an access-to-object type whose designated type is DT, |
| -- and whose Ekind is appropriate to the attribute type. The |
| -- type that is constructed is returned as the result. |
| |
| procedure Build_Access_Subprogram_Type (P : Node_Id); |
| -- Build an access to subprogram whose designated type is |
| -- the type of the prefix. If prefix is overloaded, so it the |
| -- node itself. The result is stored in Acc_Type. |
| |
| ------------------------------ |
| -- Build_Access_Object_Type -- |
| ------------------------------ |
| |
| function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is |
| Typ : Entity_Id; |
| |
| begin |
| if Aname = Name_Unrestricted_Access then |
| Typ := |
| New_Internal_Entity |
| (E_Allocator_Type, Current_Scope, Loc, 'A'); |
| else |
| Typ := |
| New_Internal_Entity |
| (E_Access_Attribute_Type, Current_Scope, Loc, 'A'); |
| end if; |
| |
| Set_Etype (Typ, Typ); |
| Init_Size_Align (Typ); |
| Set_Is_Itype (Typ); |
| Set_Associated_Node_For_Itype (Typ, N); |
| Set_Directly_Designated_Type (Typ, DT); |
| return Typ; |
| end Build_Access_Object_Type; |
| |
| ---------------------------------- |
| -- Build_Access_Subprogram_Type -- |
| ---------------------------------- |
| |
| procedure Build_Access_Subprogram_Type (P : Node_Id) is |
| Index : Interp_Index; |
| It : Interp; |
| |
| function Get_Kind (E : Entity_Id) return Entity_Kind; |
| -- Distinguish between access to regular/protected subprograms |
| |
| -------------- |
| -- Get_Kind -- |
| -------------- |
| |
| function Get_Kind (E : Entity_Id) return Entity_Kind is |
| begin |
| if Convention (E) = Convention_Protected then |
| return E_Access_Protected_Subprogram_Type; |
| else |
| return E_Access_Subprogram_Type; |
| end if; |
| end Get_Kind; |
| |
| -- Start of processing for Build_Access_Subprogram_Type |
| |
| begin |
| -- In the case of an access to subprogram, use the name of the |
| -- subprogram itself as the designated type. Type-checking in |
| -- this case compares the signatures of the designated types. |
| |
| Set_Etype (N, Any_Type); |
| |
| if not Is_Overloaded (P) then |
| if not Is_Intrinsic_Subprogram (Entity (P)) then |
| Acc_Type := |
| New_Internal_Entity |
| (Get_Kind (Entity (P)), Current_Scope, Loc, 'A'); |
| Set_Etype (Acc_Type, Acc_Type); |
| Set_Directly_Designated_Type (Acc_Type, Entity (P)); |
| Set_Etype (N, Acc_Type); |
| end if; |
| |
| else |
| Get_First_Interp (P, Index, It); |
| while Present (It.Nam) loop |
| if not Is_Intrinsic_Subprogram (It.Nam) then |
| Acc_Type := |
| New_Internal_Entity |
| (Get_Kind (It.Nam), Current_Scope, Loc, 'A'); |
| Set_Etype (Acc_Type, Acc_Type); |
| Set_Directly_Designated_Type (Acc_Type, It.Nam); |
| Add_One_Interp (N, Acc_Type, Acc_Type); |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end if; |
| |
| if Etype (N) = Any_Type then |
| Error_Attr ("prefix of % attribute cannot be intrinsic", P); |
| end if; |
| end Build_Access_Subprogram_Type; |
| |
| -- Start of processing for Analyze_Access_Attribute |
| |
| begin |
| Check_E0; |
| |
| if Nkind (P) = N_Character_Literal then |
| Error_Attr |
| ("prefix of % attribute cannot be enumeration literal", P); |
| end if; |
| |
| -- Case of access to subprogram |
| |
| if Is_Entity_Name (P) |
| and then Is_Overloadable (Entity (P)) |
| then |
| -- Not allowed for nested subprograms if No_Implicit_Dynamic_Code |
| -- restriction set (since in general a trampoline is required). |
| |
| if not Is_Library_Level_Entity (Entity (P)) then |
| Check_Restriction (No_Implicit_Dynamic_Code, P); |
| end if; |
| |
| if Is_Always_Inlined (Entity (P)) then |
| Error_Attr |
| ("prefix of % attribute cannot be Inline_Always subprogram", |
| P); |
| end if; |
| |
| -- Build the appropriate subprogram type |
| |
| Build_Access_Subprogram_Type (P); |
| |
| -- For unrestricted access, kill current values, since this |
| -- attribute allows a reference to a local subprogram that |
| -- could modify local variables to be passed out of scope |
| |
| if Aname = Name_Unrestricted_Access then |
| Kill_Current_Values; |
| end if; |
| |
| return; |
| |
| -- Component is an operation of a protected type |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Is_Overloadable (Entity (Selector_Name (P))) |
| then |
| if Ekind (Entity (Selector_Name (P))) = E_Entry then |
| Error_Attr ("prefix of % attribute must be subprogram", P); |
| end if; |
| |
| Build_Access_Subprogram_Type (Selector_Name (P)); |
| return; |
| end if; |
| |
| -- Deal with incorrect reference to a type, but note that some |
| -- accesses are allowed (references to the current type instance). |
| |
| if Is_Entity_Name (P) then |
| Typ := Entity (P); |
| |
| -- The reference may appear in an aggregate that has been expanded |
| -- into a loop. Locate scope of type definition, if any. |
| |
| Scop := Current_Scope; |
| while Ekind (Scop) = E_Loop loop |
| Scop := Scope (Scop); |
| end loop; |
| |
| if Is_Type (Typ) then |
| |
| -- OK if we are within the scope of a limited type |
| -- let's mark the component as having per object constraint |
| |
| if Is_Anonymous_Tagged_Base (Scop, Typ) then |
| Typ := Scop; |
| Set_Entity (P, Typ); |
| Set_Etype (P, Typ); |
| end if; |
| |
| if Typ = Scop then |
| declare |
| Q : Node_Id := Parent (N); |
| |
| begin |
| while Present (Q) |
| and then Nkind (Q) /= N_Component_Declaration |
| loop |
| Q := Parent (Q); |
| end loop; |
| |
| if Present (Q) then |
| Set_Has_Per_Object_Constraint ( |
| Defining_Identifier (Q), True); |
| end if; |
| end; |
| |
| if Nkind (P) = N_Expanded_Name then |
| Error_Msg_N |
| ("current instance prefix must be a direct name", P); |
| end if; |
| |
| -- If a current instance attribute appears within a |
| -- a component constraint it must appear alone; other |
| -- contexts (default expressions, within a task body) |
| -- are not subject to this restriction. |
| |
| if not In_Default_Expression |
| and then not Has_Completion (Scop) |
| and then |
| Nkind (Parent (N)) /= N_Discriminant_Association |
| and then |
| Nkind (Parent (N)) /= N_Index_Or_Discriminant_Constraint |
| then |
| Error_Msg_N |
| ("current instance attribute must appear alone", N); |
| end if; |
| |
| -- OK if we are in initialization procedure for the type |
| -- in question, in which case the reference to the type |
| -- is rewritten as a reference to the current object. |
| |
| elsif Ekind (Scop) = E_Procedure |
| and then Is_Init_Proc (Scop) |
| and then Etype (First_Formal (Scop)) = Typ |
| then |
| Rewrite (N, |
| Make_Attribute_Reference (Loc, |
| Prefix => Make_Identifier (Loc, Name_uInit), |
| Attribute_Name => Name_Unrestricted_Access)); |
| Analyze (N); |
| return; |
| |
| -- OK if a task type, this test needs sharpening up ??? |
| |
| elsif Is_Task_Type (Typ) then |
| null; |
| |
| -- Otherwise we have an error case |
| |
| else |
| Error_Attr ("% attribute cannot be applied to type", P); |
| return; |
| end if; |
| end if; |
| end if; |
| |
| -- If we fall through, we have a normal access to object case. |
| -- Unrestricted_Access is legal wherever an allocator would be |
| -- legal, so its Etype is set to E_Allocator. The expected type |
| -- of the other attributes is a general access type, and therefore |
| -- we label them with E_Access_Attribute_Type. |
| |
| if not Is_Overloaded (P) then |
| Acc_Type := Build_Access_Object_Type (P_Type); |
| Set_Etype (N, Acc_Type); |
| else |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| begin |
| Set_Etype (N, Any_Type); |
| Get_First_Interp (P, Index, It); |
| while Present (It.Typ) loop |
| Acc_Type := Build_Access_Object_Type (It.Typ); |
| Add_One_Interp (N, Acc_Type, Acc_Type); |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| end if; |
| |
| -- If we have an access to an object, and the attribute comes |
| -- from source, then set the object as potentially source modified. |
| -- We do this because the resulting access pointer can be used to |
| -- modify the variable, and we might not detect this, leading to |
| -- some junk warnings. |
| |
| if Is_Entity_Name (P) then |
| Set_Never_Set_In_Source (Entity (P), False); |
| end if; |
| |
| -- Check for aliased view unless unrestricted case. We allow |
| -- a nonaliased prefix when within an instance because the |
| -- prefix may have been a tagged formal object, which is |
| -- defined to be aliased even when the actual might not be |
| -- (other instance cases will have been caught in the generic). |
| -- Similarly, within an inlined body we know that the attribute |
| -- is legal in the original subprogram, and therefore legal in |
| -- the expansion. |
| |
| if Aname /= Name_Unrestricted_Access |
| and then not Is_Aliased_View (P) |
| and then not In_Instance |
| and then not In_Inlined_Body |
| then |
| Error_Attr ("prefix of % attribute must be aliased", P); |
| end if; |
| end Analyze_Access_Attribute; |
| |
| -------------------------------- |
| -- Check_Array_Or_Scalar_Type -- |
| -------------------------------- |
| |
| procedure Check_Array_Or_Scalar_Type is |
| Index : Entity_Id; |
| |
| D : Int; |
| -- Dimension number for array attributes |
| |
| begin |
| -- Case of string literal or string literal subtype. These cases |
| -- cannot arise from legal Ada code, but the expander is allowed |
| -- to generate them. They require special handling because string |
| -- literal subtypes do not have standard bounds (the whole idea |
| -- of these subtypes is to avoid having to generate the bounds) |
| |
| if Ekind (P_Type) = E_String_Literal_Subtype then |
| Set_Etype (N, Etype (First_Index (P_Base_Type))); |
| return; |
| |
| -- Scalar types |
| |
| elsif Is_Scalar_Type (P_Type) then |
| Check_Type; |
| |
| if Present (E1) then |
| Error_Attr ("invalid argument in % attribute", E1); |
| else |
| Set_Etype (N, P_Base_Type); |
| return; |
| end if; |
| |
| -- The following is a special test to allow 'First to apply to |
| -- private scalar types if the attribute comes from generated |
| -- code. This occurs in the case of Normalize_Scalars code. |
| |
| elsif Is_Private_Type (P_Type) |
| and then Present (Full_View (P_Type)) |
| and then Is_Scalar_Type (Full_View (P_Type)) |
| and then not Comes_From_Source (N) |
| then |
| Set_Etype (N, Implementation_Base_Type (P_Type)); |
| |
| -- Array types other than string literal subtypes handled above |
| |
| else |
| Check_Array_Type; |
| |
| -- We know prefix is an array type, or the name of an array |
| -- object, and that the expression, if present, is static |
| -- and within the range of the dimensions of the type. |
| |
| pragma Assert (Is_Array_Type (P_Type)); |
| Index := First_Index (P_Base_Type); |
| |
| if No (E1) then |
| |
| -- First dimension assumed |
| |
| Set_Etype (N, Base_Type (Etype (Index))); |
| |
| else |
| D := UI_To_Int (Intval (E1)); |
| |
| for J in 1 .. D - 1 loop |
| Next_Index (Index); |
| end loop; |
| |
| Set_Etype (N, Base_Type (Etype (Index))); |
| Set_Etype (E1, Standard_Integer); |
| end if; |
| end if; |
| end Check_Array_Or_Scalar_Type; |
| |
| ---------------------- |
| -- Check_Array_Type -- |
| ---------------------- |
| |
| procedure Check_Array_Type is |
| D : Int; |
| -- Dimension number for array attributes |
| |
| begin |
| -- If the type is a string literal type, then this must be generated |
| -- internally, and no further check is required on its legality. |
| |
| if Ekind (P_Type) = E_String_Literal_Subtype then |
| return; |
| |
| -- If the type is a composite, it is an illegal aggregate, no point |
| -- in going on. |
| |
| elsif P_Type = Any_Composite then |
| raise Bad_Attribute; |
| end if; |
| |
| -- Normal case of array type or subtype |
| |
| Check_Either_E0_Or_E1; |
| Check_Dereference; |
| |
| if Is_Array_Type (P_Type) then |
| if not Is_Constrained (P_Type) |
| and then Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| -- Note: we do not call Error_Attr here, since we prefer to |
| -- continue, using the relevant index type of the array, |
| -- even though it is unconstrained. This gives better error |
| -- recovery behavior. |
| |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("prefix for % attribute must be constrained array", P); |
| end if; |
| |
| D := Number_Dimensions (P_Type); |
| |
| else |
| if Is_Private_Type (P_Type) then |
| Error_Attr |
| ("prefix for % attribute may not be private type", P); |
| |
| elsif Is_Access_Type (P_Type) |
| and then Is_Array_Type (Designated_Type (P_Type)) |
| and then Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| Error_Attr ("prefix of % attribute cannot be access type", P); |
| |
| elsif Attr_Id = Attribute_First |
| or else |
| Attr_Id = Attribute_Last |
| then |
| Error_Attr ("invalid prefix for % attribute", P); |
| |
| else |
| Error_Attr ("prefix for % attribute must be array", P); |
| end if; |
| end if; |
| |
| if Present (E1) then |
| Resolve (E1, Any_Integer); |
| Set_Etype (E1, Standard_Integer); |
| |
| if not Is_Static_Expression (E1) |
| or else Raises_Constraint_Error (E1) |
| then |
| Flag_Non_Static_Expr |
| ("expression for dimension must be static!", E1); |
| Error_Attr; |
| |
| elsif UI_To_Int (Expr_Value (E1)) > D |
| or else UI_To_Int (Expr_Value (E1)) < 1 |
| then |
| Error_Attr ("invalid dimension number for array type", E1); |
| end if; |
| end if; |
| end Check_Array_Type; |
| |
| ------------------------- |
| -- Check_Asm_Attribute -- |
| ------------------------- |
| |
| procedure Check_Asm_Attribute is |
| begin |
| Check_Type; |
| Check_E2; |
| |
| -- Check first argument is static string expression |
| |
| Analyze_And_Resolve (E1, Standard_String); |
| |
| if Etype (E1) = Any_Type then |
| return; |
| |
| elsif not Is_OK_Static_Expression (E1) then |
| Flag_Non_Static_Expr |
| ("constraint argument must be static string expression!", E1); |
| Error_Attr; |
| end if; |
| |
| -- Check second argument is right type |
| |
| Analyze_And_Resolve (E2, Entity (P)); |
| |
| -- Note: that is all we need to do, we don't need to check |
| -- that it appears in a correct context. The Ada type system |
| -- will do that for us. |
| |
| end Check_Asm_Attribute; |
| |
| --------------------- |
| -- Check_Component -- |
| --------------------- |
| |
| procedure Check_Component is |
| begin |
| Check_E0; |
| |
| if Nkind (P) /= N_Selected_Component |
| or else |
| (Ekind (Entity (Selector_Name (P))) /= E_Component |
| and then |
| Ekind (Entity (Selector_Name (P))) /= E_Discriminant) |
| then |
| Error_Attr |
| ("prefix for % attribute must be selected component", P); |
| end if; |
| end Check_Component; |
| |
| ------------------------------------ |
| -- Check_Decimal_Fixed_Point_Type -- |
| ------------------------------------ |
| |
| procedure Check_Decimal_Fixed_Point_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Decimal_Fixed_Point_Type (P_Type) then |
| Error_Attr |
| ("prefix of % attribute must be decimal type", P); |
| end if; |
| end Check_Decimal_Fixed_Point_Type; |
| |
| ----------------------- |
| -- Check_Dereference -- |
| ----------------------- |
| |
| procedure Check_Dereference is |
| begin |
| |
| -- Case of a subtype mark |
| |
| if Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| return; |
| end if; |
| |
| -- Case of an expression |
| |
| Resolve (P); |
| |
| if Is_Access_Type (P_Type) then |
| |
| -- If there is an implicit dereference, then we must freeze |
| -- the designated type of the access type, since the type of |
| -- the referenced array is this type (see AI95-00106). |
| |
| Freeze_Before (N, Designated_Type (P_Type)); |
| |
| Rewrite (P, |
| Make_Explicit_Dereference (Sloc (P), |
| Prefix => Relocate_Node (P))); |
| |
| Analyze_And_Resolve (P); |
| P_Type := Etype (P); |
| |
| if P_Type = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| P_Base_Type := Base_Type (P_Type); |
| end if; |
| end Check_Dereference; |
| |
| ------------------------- |
| -- Check_Discrete_Type -- |
| ------------------------- |
| |
| procedure Check_Discrete_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Discrete_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be discrete type", P); |
| end if; |
| end Check_Discrete_Type; |
| |
| -------------- |
| -- Check_E0 -- |
| -------------- |
| |
| procedure Check_E0 is |
| begin |
| if Present (E1) then |
| Unexpected_Argument (E1); |
| end if; |
| end Check_E0; |
| |
| -------------- |
| -- Check_E1 -- |
| -------------- |
| |
| procedure Check_E1 is |
| begin |
| Check_Either_E0_Or_E1; |
| |
| if No (E1) then |
| |
| -- Special-case attributes that are functions and that appear as |
| -- the prefix of another attribute. Error is posted on parent. |
| |
| if Nkind (Parent (N)) = N_Attribute_Reference |
| and then (Attribute_Name (Parent (N)) = Name_Address |
| or else |
| Attribute_Name (Parent (N)) = Name_Code_Address |
| or else |
| Attribute_Name (Parent (N)) = Name_Access) |
| then |
| Error_Msg_Name_1 := Attribute_Name (Parent (N)); |
| Error_Msg_N ("illegal prefix for % attribute", Parent (N)); |
| Set_Etype (Parent (N), Any_Type); |
| Set_Entity (Parent (N), Any_Type); |
| raise Bad_Attribute; |
| |
| else |
| Error_Attr ("missing argument for % attribute", N); |
| end if; |
| end if; |
| end Check_E1; |
| |
| -------------- |
| -- Check_E2 -- |
| -------------- |
| |
| procedure Check_E2 is |
| begin |
| if No (E1) then |
| Error_Attr ("missing arguments for % attribute (2 required)", N); |
| elsif No (E2) then |
| Error_Attr ("missing argument for % attribute (2 required)", N); |
| end if; |
| end Check_E2; |
| |
| --------------------------- |
| -- Check_Either_E0_Or_E1 -- |
| --------------------------- |
| |
| procedure Check_Either_E0_Or_E1 is |
| begin |
| if Present (E2) then |
| Unexpected_Argument (E2); |
| end if; |
| end Check_Either_E0_Or_E1; |
| |
| ---------------------- |
| -- Check_Enum_Image -- |
| ---------------------- |
| |
| procedure Check_Enum_Image is |
| Lit : Entity_Id; |
| |
| begin |
| if Is_Enumeration_Type (P_Base_Type) then |
| Lit := First_Literal (P_Base_Type); |
| while Present (Lit) loop |
| Set_Referenced (Lit); |
| Next_Literal (Lit); |
| end loop; |
| end if; |
| end Check_Enum_Image; |
| |
| ---------------------------- |
| -- Check_Fixed_Point_Type -- |
| ---------------------------- |
| |
| procedure Check_Fixed_Point_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Fixed_Point_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be fixed point type", P); |
| end if; |
| end Check_Fixed_Point_Type; |
| |
| ------------------------------ |
| -- Check_Fixed_Point_Type_0 -- |
| ------------------------------ |
| |
| procedure Check_Fixed_Point_Type_0 is |
| begin |
| Check_Fixed_Point_Type; |
| Check_E0; |
| end Check_Fixed_Point_Type_0; |
| |
| ------------------------------- |
| -- Check_Floating_Point_Type -- |
| ------------------------------- |
| |
| procedure Check_Floating_Point_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Floating_Point_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be float type", P); |
| end if; |
| end Check_Floating_Point_Type; |
| |
| --------------------------------- |
| -- Check_Floating_Point_Type_0 -- |
| --------------------------------- |
| |
| procedure Check_Floating_Point_Type_0 is |
| begin |
| Check_Floating_Point_Type; |
| Check_E0; |
| end Check_Floating_Point_Type_0; |
| |
| --------------------------------- |
| -- Check_Floating_Point_Type_1 -- |
| --------------------------------- |
| |
| procedure Check_Floating_Point_Type_1 is |
| begin |
| Check_Floating_Point_Type; |
| Check_E1; |
| end Check_Floating_Point_Type_1; |
| |
| --------------------------------- |
| -- Check_Floating_Point_Type_2 -- |
| --------------------------------- |
| |
| procedure Check_Floating_Point_Type_2 is |
| begin |
| Check_Floating_Point_Type; |
| Check_E2; |
| end Check_Floating_Point_Type_2; |
| |
| ------------------------ |
| -- Check_Integer_Type -- |
| ------------------------ |
| |
| procedure Check_Integer_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Integer_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be integer type", P); |
| end if; |
| end Check_Integer_Type; |
| |
| ------------------------ |
| -- Check_Library_Unit -- |
| ------------------------ |
| |
| procedure Check_Library_Unit is |
| begin |
| if not Is_Compilation_Unit (Entity (P)) then |
| Error_Attr ("prefix of % attribute must be library unit", P); |
| end if; |
| end Check_Library_Unit; |
| |
| -------------------------------- |
| -- Check_Modular_Integer_Type -- |
| -------------------------------- |
| |
| procedure Check_Modular_Integer_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Modular_Integer_Type (P_Type) then |
| Error_Attr |
| ("prefix of % attribute must be modular integer type", P); |
| end if; |
| end Check_Modular_Integer_Type; |
| |
| ------------------------------- |
| -- Check_Not_Incomplete_Type -- |
| ------------------------------- |
| |
| procedure Check_Not_Incomplete_Type is |
| E : Entity_Id; |
| Typ : Entity_Id; |
| |
| begin |
| -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit |
| -- dereference we have to check wrong uses of incomplete types |
| -- (other wrong uses are checked at their freezing point). |
| |
| -- Example 1: Limited-with |
| |
| -- limited with Pkg; |
| -- package P is |
| -- type Acc is access Pkg.T; |
| -- X : Acc; |
| -- S : Integer := X.all'Size; -- ERROR |
| -- end P; |
| |
| -- Example 2: Tagged incomplete |
| |
| -- type T is tagged; |
| -- type Acc is access all T; |
| -- X : Acc; |
| -- S : constant Integer := X.all'Size; -- ERROR |
| -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR |
| |
| if Ada_Version >= Ada_05 |
| and then Nkind (P) = N_Explicit_Dereference |
| then |
| E := P; |
| while Nkind (E) = N_Explicit_Dereference loop |
| E := Prefix (E); |
| end loop; |
| |
| if From_With_Type (Etype (E)) then |
| Error_Attr |
| ("prefix of % attribute cannot be an incomplete type", P); |
| |
| else |
| if Is_Access_Type (Etype (E)) then |
| Typ := Directly_Designated_Type (Etype (E)); |
| else |
| Typ := Etype (E); |
| end if; |
| |
| if Ekind (Typ) = E_Incomplete_Type |
| and then No (Full_View (Typ)) |
| then |
| Error_Attr |
| ("prefix of % attribute cannot be an incomplete type", P); |
| end if; |
| end if; |
| end if; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| or else In_Default_Expression |
| then |
| return; |
| else |
| Check_Fully_Declared (P_Type, P); |
| end if; |
| end Check_Not_Incomplete_Type; |
| |
| ---------------------------- |
| -- Check_Object_Reference -- |
| ---------------------------- |
| |
| procedure Check_Object_Reference (P : Node_Id) is |
| Rtyp : Entity_Id; |
| |
| begin |
| -- If we need an object, and we have a prefix that is the name of |
| -- a function entity, convert it into a function call. |
| |
| if Is_Entity_Name (P) |
| and then Ekind (Entity (P)) = E_Function |
| then |
| Rtyp := Etype (Entity (P)); |
| |
| Rewrite (P, |
| Make_Function_Call (Sloc (P), |
| Name => Relocate_Node (P))); |
| |
| Analyze_And_Resolve (P, Rtyp); |
| |
| -- Otherwise we must have an object reference |
| |
| elsif not Is_Object_Reference (P) then |
| Error_Attr ("prefix of % attribute must be object", P); |
| end if; |
| end Check_Object_Reference; |
| |
| ------------------------ |
| -- Check_Program_Unit -- |
| ------------------------ |
| |
| procedure Check_Program_Unit is |
| begin |
| if Is_Entity_Name (P) then |
| declare |
| K : constant Entity_Kind := Ekind (Entity (P)); |
| T : constant Entity_Id := Etype (Entity (P)); |
| |
| begin |
| if K in Subprogram_Kind |
| or else K in Task_Kind |
| or else K in Protected_Kind |
| or else K = E_Package |
| or else K in Generic_Unit_Kind |
| or else (K = E_Variable |
| and then |
| (Is_Task_Type (T) |
| or else |
| Is_Protected_Type (T))) |
| then |
| return; |
| end if; |
| end; |
| end if; |
| |
| Error_Attr ("prefix of % attribute must be program unit", P); |
| end Check_Program_Unit; |
| |
| --------------------- |
| -- Check_Real_Type -- |
| --------------------- |
| |
| procedure Check_Real_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Real_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be real type", P); |
| end if; |
| end Check_Real_Type; |
| |
| ----------------------- |
| -- Check_Scalar_Type -- |
| ----------------------- |
| |
| procedure Check_Scalar_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Scalar_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be scalar type", P); |
| end if; |
| end Check_Scalar_Type; |
| |
| --------------------------- |
| -- Check_Standard_Prefix -- |
| --------------------------- |
| |
| procedure Check_Standard_Prefix is |
| begin |
| Check_E0; |
| |
| if Nkind (P) /= N_Identifier |
| or else Chars (P) /= Name_Standard |
| then |
| Error_Attr ("only allowed prefix for % attribute is Standard", P); |
| end if; |
| |
| end Check_Standard_Prefix; |
| |
| ---------------------------- |
| -- Check_Stream_Attribute -- |
| ---------------------------- |
| |
| procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is |
| Etyp : Entity_Id; |
| Btyp : Entity_Id; |
| begin |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| -- With the exception of 'Input, Stream attributes are procedures, |
| -- and can only appear at the position of procedure calls. We check |
| -- for this here, before they are rewritten, to give a more precise |
| -- diagnostic. |
| |
| if Nam = TSS_Stream_Input then |
| null; |
| |
| elsif Is_List_Member (N) |
| and then Nkind (Parent (N)) /= N_Procedure_Call_Statement |
| and then Nkind (Parent (N)) /= N_Aggregate |
| then |
| null; |
| |
| else |
| Error_Attr |
| ("invalid context for attribute%, which is a procedure", N); |
| end if; |
| |
| Check_Type; |
| Btyp := Implementation_Base_Type (P_Type); |
| |
| -- Stream attributes not allowed on limited types unless the |
| -- attribute reference was generated by the expander (in which |
| -- case the underlying type will be used, as described in Sinfo), |
| -- or the attribute was specified explicitly for the type itself |
| -- or one of its ancestors (taking visibility rules into account if |
| -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp |
| -- (with no visibility restriction). |
| |
| if Comes_From_Source (N) |
| and then not Stream_Attribute_Available (P_Type, Nam) |
| and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert) |
| then |
| Error_Msg_Name_1 := Aname; |
| |
| if Is_Limited_Type (P_Type) then |
| Error_Msg_NE |
| ("limited type& has no% attribute", P, P_Type); |
| Explain_Limited_Type (P_Type, P); |
| else |
| Error_Msg_NE |
| ("attribute% for type& is not available", P, P_Type); |
| end if; |
| end if; |
| |
| -- Check for violation of restriction No_Stream_Attributes |
| |
| if Is_RTE (P_Type, RE_Exception_Id) |
| or else |
| Is_RTE (P_Type, RE_Exception_Occurrence) |
| then |
| Check_Restriction (No_Exception_Registration, P); |
| end if; |
| |
| -- Here we must check that the first argument is an access type |
| -- that is compatible with Ada.Streams.Root_Stream_Type'Class. |
| |
| Analyze_And_Resolve (E1); |
| Etyp := Etype (E1); |
| |
| -- Note: the double call to Root_Type here is needed because the |
| -- root type of a class-wide type is the corresponding type (e.g. |
| -- X for X'Class, and we really want to go to the root. |
| |
| if not Is_Access_Type (Etyp) |
| or else Root_Type (Root_Type (Designated_Type (Etyp))) /= |
| RTE (RE_Root_Stream_Type) |
| then |
| Error_Attr |
| ("expected access to Ada.Streams.Root_Stream_Type''Class", E1); |
| end if; |
| |
| -- Check that the second argument is of the right type if there is |
| -- one (the Input attribute has only one argument so this is skipped) |
| |
| if Present (E2) then |
| Analyze (E2); |
| |
| if Nam = TSS_Stream_Read |
| and then not Is_OK_Variable_For_Out_Formal (E2) |
| then |
| Error_Attr |
| ("second argument of % attribute must be a variable", E2); |
| end if; |
| |
| Resolve (E2, P_Type); |
| end if; |
| end Check_Stream_Attribute; |
| |
| ----------------------- |
| -- Check_Task_Prefix -- |
| ----------------------- |
| |
| procedure Check_Task_Prefix is |
| begin |
| Analyze (P); |
| |
| -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to |
| -- task interface class-wide types. |
| |
| if Is_Task_Type (Etype (P)) |
| or else (Is_Access_Type (Etype (P)) |
| and then Is_Task_Type (Designated_Type (Etype (P)))) |
| or else (Ada_Version >= Ada_05 |
| and then Ekind (Etype (P)) = E_Class_Wide_Type |
| and then Is_Interface (Etype (P)) |
| and then Is_Task_Interface (Etype (P))) |
| then |
| Resolve (P); |
| |
| else |
| if Ada_Version >= Ada_05 then |
| Error_Attr ("prefix of % attribute must be a task or a task " |
| & "interface class-wide object", P); |
| |
| else |
| Error_Attr ("prefix of % attribute must be a task", P); |
| end if; |
| end if; |
| end Check_Task_Prefix; |
| |
| ---------------- |
| -- Check_Type -- |
| ---------------- |
| |
| -- The possibilities are an entity name denoting a type, or an |
| -- attribute reference that denotes a type (Base or Class). If |
| -- the type is incomplete, replace it with its full view. |
| |
| procedure Check_Type is |
| begin |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| then |
| Error_Attr ("prefix of % attribute must be a type", P); |
| |
| elsif Ekind (Entity (P)) = E_Incomplete_Type |
| and then Present (Full_View (Entity (P))) |
| then |
| P_Type := Full_View (Entity (P)); |
| Set_Entity (P, P_Type); |
| end if; |
| end Check_Type; |
| |
| --------------------- |
| -- Check_Unit_Name -- |
| --------------------- |
| |
| procedure Check_Unit_Name (Nod : Node_Id) is |
| begin |
| if Nkind (Nod) = N_Identifier then |
| return; |
| |
| elsif Nkind (Nod) = N_Selected_Component then |
| Check_Unit_Name (Prefix (Nod)); |
| |
| if Nkind (Selector_Name (Nod)) = N_Identifier then |
| return; |
| end if; |
| end if; |
| |
| Error_Attr ("argument for % attribute must be unit name", P); |
| end Check_Unit_Name; |
| |
| ---------------- |
| -- Error_Attr -- |
| ---------------- |
| |
| procedure Error_Attr is |
| begin |
| Set_Etype (N, Any_Type); |
| Set_Entity (N, Any_Type); |
| raise Bad_Attribute; |
| end Error_Attr; |
| |
| procedure Error_Attr (Msg : String; Error_Node : Node_Id) is |
| begin |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N (Msg, Error_Node); |
| Error_Attr; |
| end Error_Attr; |
| |
| ---------------------------- |
| -- Legal_Formal_Attribute -- |
| ---------------------------- |
| |
| procedure Legal_Formal_Attribute is |
| begin |
| Check_E0; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| then |
| Error_Attr ("prefix of % attribute must be generic type", N); |
| |
| elsif Is_Generic_Actual_Type (Entity (P)) |
| or else In_Instance |
| or else In_Inlined_Body |
| then |
| null; |
| |
| elsif Is_Generic_Type (Entity (P)) then |
| if not Is_Indefinite_Subtype (Entity (P)) then |
| Error_Attr |
| ("prefix of % attribute must be indefinite generic type", N); |
| end if; |
| |
| else |
| Error_Attr |
| ("prefix of % attribute must be indefinite generic type", N); |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| end Legal_Formal_Attribute; |
| |
| ------------------------ |
| -- Standard_Attribute -- |
| ------------------------ |
| |
| procedure Standard_Attribute (Val : Int) is |
| begin |
| Check_Standard_Prefix; |
| |
| -- First a special check (more like a kludge really). For GNAT5 |
| -- on Windows, the alignments in GCC are severely mixed up. In |
| -- particular, we have a situation where the maximum alignment |
| -- that GCC thinks is possible is greater than the guaranteed |
| -- alignment at run-time. That causes many problems. As a partial |
| -- cure for this situation, we force a value of 4 for the maximum |
| -- alignment attribute on this target. This still does not solve |
| -- all problems, but it helps. |
| |
| -- A further (even more horrible) dimension to this kludge is now |
| -- installed. There are two uses for Maximum_Alignment, one is to |
| -- determine the maximum guaranteed alignment, that's the one we |
| -- want the kludge to yield as 4. The other use is to maximally |
| -- align objects, we can't use 4 here, since for example, long |
| -- long integer has an alignment of 8, so we will get errors. |
| |
| -- It is of course impossible to determine which use the programmer |
| -- has in mind, but an approximation for now is to disconnect the |
| -- kludge if the attribute appears in an alignment clause. |
| |
| -- To be removed if GCC ever gets its act together here ??? |
| |
| Alignment_Kludge : declare |
| P : Node_Id; |
| |
| function On_X86 return Boolean; |
| -- Determine if target is x86 (ia32), return True if so |
| |
| ------------ |
| -- On_X86 -- |
| ------------ |
| |
| function On_X86 return Boolean is |
| T : constant String := Sdefault.Target_Name.all; |
| |
| begin |
| -- There is no clean way to check this. That's not surprising, |
| -- the front end should not be doing this kind of test ???. The |
| -- way we do it is test for either "86" or "pentium" being in |
| -- the string for the target name. However, we need to exclude |
| -- x86_64 for this check. |
| |
| for J in T'First .. T'Last - 1 loop |
| if (T (J .. J + 1) = "86" |
| and then |
| (J + 4 > T'Last |
| or else T (J + 2 .. J + 4) /= "_64")) |
| or else (J <= T'Last - 6 |
| and then T (J .. J + 6) = "pentium") |
| then |
| return True; |
| end if; |
| end loop; |
| |
| return False; |
| end On_X86; |
| |
| begin |
| if Aname = Name_Maximum_Alignment and then On_X86 then |
| P := Parent (N); |
| |
| while Nkind (P) in N_Subexpr loop |
| P := Parent (P); |
| end loop; |
| |
| if Nkind (P) /= N_Attribute_Definition_Clause |
| or else Chars (P) /= Name_Alignment |
| then |
| Rewrite (N, Make_Integer_Literal (Loc, 4)); |
| Analyze (N); |
| return; |
| end if; |
| end if; |
| end Alignment_Kludge; |
| |
| -- Normally we get the value from gcc ??? |
| |
| Rewrite (N, Make_Integer_Literal (Loc, Val)); |
| Analyze (N); |
| end Standard_Attribute; |
| |
| ------------------------- |
| -- Unexpected Argument -- |
| ------------------------- |
| |
| procedure Unexpected_Argument (En : Node_Id) is |
| begin |
| Error_Attr ("unexpected argument for % attribute", En); |
| end Unexpected_Argument; |
| |
| ------------------------------------------------- |
| -- Validate_Non_Static_Attribute_Function_Call -- |
| ------------------------------------------------- |
| |
| -- This function should be moved to Sem_Dist ??? |
| |
| procedure Validate_Non_Static_Attribute_Function_Call is |
| begin |
| if In_Preelaborated_Unit |
| and then not In_Subprogram_Or_Concurrent_Unit |
| then |
| Flag_Non_Static_Expr |
| ("non-static function call in preelaborated unit!", N); |
| end if; |
| end Validate_Non_Static_Attribute_Function_Call; |
| |
| ----------------------------------------------- |
| -- Start of Processing for Analyze_Attribute -- |
| ----------------------------------------------- |
| |
| begin |
| -- Immediate return if unrecognized attribute (already diagnosed |
| -- by parser, so there is nothing more that we need to do) |
| |
| if not Is_Attribute_Name (Aname) then |
| raise Bad_Attribute; |
| end if; |
| |
| -- Deal with Ada 83 and Features issues |
| |
| if Comes_From_Source (N) then |
| if not Attribute_83 (Attr_Id) then |
| if Ada_Version = Ada_83 and then Comes_From_Source (N) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N ("(Ada 83) attribute% is not standard?", N); |
| end if; |
| |
| if Attribute_Impl_Def (Attr_Id) then |
| Check_Restriction (No_Implementation_Attributes, N); |
| end if; |
| end if; |
| end if; |
| |
| -- Remote access to subprogram type access attribute reference needs |
| -- unanalyzed copy for tree transformation. The analyzed copy is used |
| -- for its semantic information (whether prefix is a remote subprogram |
| -- name), the unanalyzed copy is used to construct new subtree rooted |
| -- with N_Aggregate which represents a fat pointer aggregate. |
| |
| if Aname = Name_Access then |
| Discard_Node (Copy_Separate_Tree (N)); |
| end if; |
| |
| -- Analyze prefix and exit if error in analysis. If the prefix is an |
| -- incomplete type, use full view if available. A special case is |
| -- that we never analyze the prefix of an Elab_Body or Elab_Spec |
| -- or UET_Address attribute. |
| |
| if Aname /= Name_Elab_Body |
| and then |
| Aname /= Name_Elab_Spec |
| and then |
| Aname /= Name_UET_Address |
| then |
| Analyze (P); |
| P_Type := Etype (P); |
| |
| if Is_Entity_Name (P) |
| and then Present (Entity (P)) |
| and then Is_Type (Entity (P)) |
| then |
| if Ekind (Entity (P)) = E_Incomplete_Type then |
| P_Type := Get_Full_View (P_Type); |
| Set_Entity (P, P_Type); |
| Set_Etype (P, P_Type); |
| |
| elsif Entity (P) = Current_Scope |
| and then Is_Record_Type (Entity (P)) |
| then |
| |
| -- Use of current instance within the type. Verify that if the |
| -- attribute appears within a constraint, it yields an access |
| -- type, other uses are illegal. |
| |
| declare |
| Par : Node_Id; |
| |
| begin |
| Par := Parent (N); |
| while Present (Par) |
| and then Nkind (Parent (Par)) /= N_Component_Definition |
| loop |
| Par := Parent (Par); |
| end loop; |
| |
| if Present (Par) |
| and then Nkind (Par) = N_Subtype_Indication |
| then |
| if Attr_Id /= Attribute_Access |
| and then Attr_Id /= Attribute_Unchecked_Access |
| and then Attr_Id /= Attribute_Unrestricted_Access |
| then |
| Error_Msg_N |
| ("in a constraint the current instance can only" |
| & " be used with an access attribute", N); |
| end if; |
| end if; |
| end; |
| end if; |
| end if; |
| |
| if P_Type = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| P_Base_Type := Base_Type (P_Type); |
| end if; |
| |
| -- Analyze expressions that may be present, exiting if an error occurs |
| |
| if No (Exprs) then |
| E1 := Empty; |
| E2 := Empty; |
| |
| else |
| E1 := First (Exprs); |
| Analyze (E1); |
| |
| -- Check for missing or bad expression (result of previous error) |
| |
| if No (E1) or else Etype (E1) = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| E2 := Next (E1); |
| |
| if Present (E2) then |
| Analyze (E2); |
| |
| if Etype (E2) = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| if Present (Next (E2)) then |
| Unexpected_Argument (Next (E2)); |
| end if; |
| end if; |
| end if; |
| |
| -- Ada 2005 (AI-345): Ensure that the compiler gives exactly the current |
| -- output compiling in Ada 95 mode |
| |
| if Ada_Version < Ada_05 |
| and then Is_Overloaded (P) |
| and then Aname /= Name_Access |
| and then Aname /= Name_Address |
| and then Aname /= Name_Code_Address |
| and then Aname /= Name_Count |
| and then Aname /= Name_Unchecked_Access |
| then |
| Error_Attr ("ambiguous prefix for % attribute", P); |
| |
| elsif Ada_Version >= Ada_05 |
| and then Is_Overloaded (P) |
| and then Aname /= Name_Access |
| and then Aname /= Name_Address |
| and then Aname /= Name_Code_Address |
| and then Aname /= Name_Unchecked_Access |
| then |
| -- Ada 2005 (AI-345): Since protected and task types have primitive |
| -- entry wrappers, the attributes Count, Caller and AST_Entry require |
| -- a context check |
| |
| if Ada_Version >= Ada_05 |
| and then (Aname = Name_Count |
| or else Aname = Name_Caller |
| or else Aname = Name_AST_Entry) |
| then |
| declare |
| Count : Natural := 0; |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (P, I, It); |
| |
| while Present (It.Nam) loop |
| if Comes_From_Source (It.Nam) then |
| Count := Count + 1; |
| else |
| Remove_Interp (I); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| if Count > 1 then |
| Error_Attr ("ambiguous prefix for % attribute", P); |
| else |
| Set_Is_Overloaded (P, False); |
| end if; |
| end; |
| |
| else |
| Error_Attr ("ambiguous prefix for % attribute", P); |
| end if; |
| end if; |
| |
| -- Remaining processing depends on attribute |
| |
| case Attr_Id is |
| |
| ------------------ |
| -- Abort_Signal -- |
| ------------------ |
| |
| when Attribute_Abort_Signal => |
| Check_Standard_Prefix; |
| Rewrite (N, |
| New_Reference_To (Stand.Abort_Signal, Loc)); |
| Analyze (N); |
| |
| ------------ |
| -- Access -- |
| ------------ |
| |
| when Attribute_Access => |
| Analyze_Access_Attribute; |
| |
| ------------- |
| -- Address -- |
| ------------- |
| |
| when Attribute_Address => |
| Check_E0; |
| |
| -- Check for some junk cases, where we have to allow the address |
| -- attribute but it does not make much sense, so at least for now |
| -- just replace with Null_Address. |
| |
| -- We also do this if the prefix is a reference to the AST_Entry |
| -- attribute. If expansion is active, the attribute will be |
| -- replaced by a function call, and address will work fine and |
| -- get the proper value, but if expansion is not active, then |
| -- the check here allows proper semantic analysis of the reference. |
| |
| -- An Address attribute created by expansion is legal even when it |
| -- applies to other entity-denoting expressions. |
| |
| if Is_Entity_Name (P) then |
| declare |
| Ent : constant Entity_Id := Entity (P); |
| |
| begin |
| if Is_Subprogram (Ent) then |
| if not Is_Library_Level_Entity (Ent) then |
| Check_Restriction (No_Implicit_Dynamic_Code, P); |
| end if; |
| |
| Set_Address_Taken (Ent); |
| |
| -- An Address attribute is accepted when generated by |
| -- the compiler for dispatching operation, and an error |
| -- is issued once the subprogram is frozen (to avoid |
| -- confusing errors about implicit uses of Address in |
| -- the dispatch table initialization). |
| |
| if Is_Always_Inlined (Entity (P)) |
| and then Comes_From_Source (P) |
| then |
| Error_Attr |
| ("prefix of % attribute cannot be Inline_Always" & |
| " subprogram", P); |
| end if; |
| |
| elsif Is_Object (Ent) |
| or else Ekind (Ent) = E_Label |
| then |
| Set_Address_Taken (Ent); |
| |
| -- If we have an address of an object, and the attribute |
| -- comes from source, then set the object as potentially |
| -- source modified. We do this because the resulting address |
| -- can potentially be used to modify the variable and we |
| -- might not detect this, leading to some junk warnings. |
| |
| Set_Never_Set_In_Source (Ent, False); |
| |
| elsif (Is_Concurrent_Type (Etype (Ent)) |
| and then Etype (Ent) = Base_Type (Ent)) |
| or else Ekind (Ent) = E_Package |
| or else Is_Generic_Unit (Ent) |
| then |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N))); |
| |
| else |
| Error_Attr ("invalid prefix for % attribute", P); |
| end if; |
| end; |
| |
| elsif Nkind (P) = N_Attribute_Reference |
| and then Attribute_Name (P) = Name_AST_Entry |
| then |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N))); |
| |
| elsif Is_Object_Reference (P) then |
| null; |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Is_Subprogram (Entity (Selector_Name (P))) |
| then |
| null; |
| |
| -- What exactly are we allowing here ??? and is this properly |
| -- documented in the sinfo documentation for this node ??? |
| |
| elsif not Comes_From_Source (N) then |
| null; |
| |
| else |
| Error_Attr ("invalid prefix for % attribute", P); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Address)); |
| |
| ------------------ |
| -- Address_Size -- |
| ------------------ |
| |
| when Attribute_Address_Size => |
| Standard_Attribute (System_Address_Size); |
| |
| -------------- |
| -- Adjacent -- |
| -------------- |
| |
| when Attribute_Adjacent => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| |
| --------- |
| -- Aft -- |
| --------- |
| |
| when Attribute_Aft => |
| Check_Fixed_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Alignment -- |
| --------------- |
| |
| when Attribute_Alignment => |
| |
| -- Don't we need more checking here, cf Size ??? |
| |
| Check_E0; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Asm_Input -- |
| --------------- |
| |
| when Attribute_Asm_Input => |
| Check_Asm_Attribute; |
| Set_Etype (N, RTE (RE_Asm_Input_Operand)); |
| |
| ---------------- |
| -- Asm_Output -- |
| ---------------- |
| |
| when Attribute_Asm_Output => |
| Check_Asm_Attribute; |
| |
| if Etype (E2) = Any_Type then |
| return; |
| |
| elsif Aname = Name_Asm_Output then |
| if not Is_Variable (E2) then |
| Error_Attr |
| ("second argument for Asm_Output is not variable", E2); |
| end if; |
| end if; |
| |
| Note_Possible_Modification (E2); |
| Set_Etype (N, RTE (RE_Asm_Output_Operand)); |
| |
| --------------- |
| -- AST_Entry -- |
| --------------- |
| |
| when Attribute_AST_Entry => AST_Entry : declare |
| Ent : Entity_Id; |
| Pref : Node_Id; |
| Ptyp : Entity_Id; |
| |
| Indexed : Boolean; |
| -- Indicates if entry family index is present. Note the coding |
| -- here handles the entry family case, but in fact it cannot be |
| -- executed currently, because pragma AST_Entry does not permit |
| -- the specification of an entry family. |
| |
| procedure Bad_AST_Entry; |
| -- Signal a bad AST_Entry pragma |
| |
| function OK_Entry (E : Entity_Id) return Boolean; |
| -- Checks that E is of an appropriate entity kind for an entry |
| -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index |
| -- is set True for the entry family case). In the True case, |
| -- makes sure that Is_AST_Entry is set on the entry. |
| |
| procedure Bad_AST_Entry is |
| begin |
| Error_Attr ("prefix for % attribute must be task entry", P); |
| end Bad_AST_Entry; |
| |
| function OK_Entry (E : Entity_Id) return Boolean is |
| Result : Boolean; |
| |
| begin |
| if Indexed then |
| Result := (Ekind (E) = E_Entry_Family); |
| else |
| Result := (Ekind (E) = E_Entry); |
| end if; |
| |
| if Result then |
| if not Is_AST_Entry (E) then |
| Error_Msg_Name_2 := Aname; |
| Error_Attr |
| ("% attribute requires previous % pragma", P); |
| end if; |
| end if; |
| |
| return Result; |
| end OK_Entry; |
| |
| -- Start of processing for AST_Entry |
| |
| begin |
| Check_VMS (N); |
| Check_E0; |
| |
| -- Deal with entry family case |
| |
| if Nkind (P) = N_Indexed_Component then |
| Pref := Prefix (P); |
| Indexed := True; |
| else |
| Pref := P; |
| Indexed := False; |
| end if; |
| |
| Ptyp := Etype (Pref); |
| |
| if Ptyp = Any_Type or else Error_Posted (Pref) then |
| return; |
| end if; |
| |
| -- If the prefix is a selected component whose prefix is of an |
| -- access type, then introduce an explicit dereference. |
| -- ??? Could we reuse Check_Dereference here? |
| |
| if Nkind (Pref) = N_Selected_Component |
| and then Is_Access_Type (Ptyp) |
| then |
| Rewrite (Pref, |
| Make_Explicit_Dereference (Sloc (Pref), |
| Relocate_Node (Pref))); |
| Analyze_And_Resolve (Pref, Designated_Type (Ptyp)); |
| end if; |
| |
| -- Prefix can be of the form a.b, where a is a task object |
| -- and b is one of the entries of the corresponding task type. |
| |
| if Nkind (Pref) = N_Selected_Component |
| and then OK_Entry (Entity (Selector_Name (Pref))) |
| and then Is_Object_Reference (Prefix (Pref)) |
| and then Is_Task_Type (Etype (Prefix (Pref))) |
| then |
| null; |
| |
| -- Otherwise the prefix must be an entry of a containing task, |
| -- or of a variable of the enclosing task type. |
| |
| else |
| if Nkind (Pref) = N_Identifier |
| or else Nkind (Pref) = N_Expanded_Name |
| then |
| Ent := Entity (Pref); |
| |
| if not OK_Entry (Ent) |
| or else not In_Open_Scopes (Scope (Ent)) |
| then |
| Bad_AST_Entry; |
| end if; |
| |
| else |
| Bad_AST_Entry; |
| end if; |
| end if; |
| |
| Set_Etype (N, RTE (RE_AST_Handler)); |
| end AST_Entry; |
| |
| ---------- |
| -- Base -- |
| ---------- |
| |
| -- Note: when the base attribute appears in the context of a subtype |
| -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by |
| -- the following circuit. |
| |
| when Attribute_Base => Base : declare |
| Typ : Entity_Id; |
| |
| begin |
| Check_Either_E0_Or_E1; |
| Find_Type (P); |
| Typ := Entity (P); |
| |
| if Ada_Version >= Ada_95 |
| and then not Is_Scalar_Type (Typ) |
| and then not Is_Generic_Type (Typ) |
| then |
| Error_Msg_N ("prefix of Base attribute must be scalar type", N); |
| |
| elsif Sloc (Typ) = Standard_Location |
| and then Base_Type (Typ) = Typ |
| and then Warn_On_Redundant_Constructs |
| then |
| Error_Msg_NE |
| ("?redudant attribute, & is its own base type", N, Typ); |
| end if; |
| |
| Set_Etype (N, Base_Type (Entity (P))); |
| |
| -- If we have an expression present, then really this is a conversion |
| -- and the tree must be reformed. Note that this is one of the cases |
| -- in which we do a replace rather than a rewrite, because the |
| -- original tree is junk. |
| |
| if Present (E1) then |
| Replace (N, |
| Make_Type_Conversion (Loc, |
| Subtype_Mark => |
| Make_Attribute_Reference (Loc, |
| Prefix => Prefix (N), |
| Attribute_Name => Name_Base), |
| Expression => Relocate_Node (E1))); |
| |
| -- E1 may be overloaded, and its interpretations preserved |
| |
| Save_Interps (E1, Expression (N)); |
| Analyze (N); |
| |
| -- For other cases, set the proper type as the entity of the |
| -- attribute reference, and then rewrite the node to be an |
| -- occurrence of the referenced base type. This way, no one |
| -- else in the compiler has to worry about the base attribute. |
| |
| else |
| Set_Entity (N, Base_Type (Entity (P))); |
| Rewrite (N, |
| New_Reference_To (Entity (N), Loc)); |
| Analyze (N); |
| end if; |
| end Base; |
| |
| --------- |
| -- Bit -- |
| --------- |
| |
| when Attribute_Bit => Bit : |
| begin |
| Check_E0; |
| |
| if not Is_Object_Reference (P) then |
| Error_Attr ("prefix for % attribute must be object", P); |
| |
| -- What about the access object cases ??? |
| |
| else |
| null; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| end Bit; |
| |
| --------------- |
| -- Bit_Order -- |
| --------------- |
| |
| when Attribute_Bit_Order => Bit_Order : |
| begin |
| Check_E0; |
| Check_Type; |
| |
| if not Is_Record_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be record type", P); |
| end if; |
| |
| if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_High_Order_First), Loc)); |
| else |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_Low_Order_First), Loc)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Bit_Order)); |
| Resolve (N); |
| |
| -- Reset incorrect indication of staticness |
| |
| Set_Is_Static_Expression (N, False); |
| end Bit_Order; |
| |
| ------------------ |
| -- Bit_Position -- |
| ------------------ |
| |
| -- Note: in generated code, we can have a Bit_Position attribute |
| -- applied to a (naked) record component (i.e. the prefix is an |
| -- identifier that references an E_Component or E_Discriminant |
| -- entity directly, and this is interpreted as expected by Gigi. |
| -- The following code will not tolerate such usage, but when the |
| -- expander creates this special case, it marks it as analyzed |
| -- immediately and sets an appropriate type. |
| |
| when Attribute_Bit_Position => |
| |
| if Comes_From_Source (N) then |
| Check_Component; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| when Attribute_Body_Version => |
| Check_E0; |
| Check_Program_Unit; |
| Set_Etype (N, RTE (RE_Version_String)); |
| |
| -------------- |
| -- Callable -- |
| -------------- |
| |
| when Attribute_Callable => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| Check_Task_Prefix; |
| |
| ------------ |
| -- Caller -- |
| ------------ |
| |
| when Attribute_Caller => Caller : declare |
| Ent : Entity_Id; |
| S : Entity_Id; |
| |
| begin |
| Check_E0; |
| |
| if Nkind (P) = N_Identifier |
| or else Nkind (P) = N_Expanded_Name |
| then |
| Ent := Entity (P); |
| |
| if not Is_Entry (Ent) then |
| Error_Attr ("invalid entry name", N); |
| end if; |
| |
| else |
| Error_Attr ("invalid entry name", N); |
| return; |
| end if; |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| S := Scope_Stack.Table (J).Entity; |
| |
| if S = Scope (Ent) then |
| Error_Attr ("Caller must appear in matching accept or body", N); |
| elsif S = Ent then |
| exit; |
| end if; |
| end loop; |
| |
| Set_Etype (N, RTE (RO_AT_Task_Id)); |
| end Caller; |
| |
| ------------- |
| -- Ceiling -- |
| ------------- |
| |
| when Attribute_Ceiling => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ----------- |
| -- Class -- |
| ----------- |
| |
| when Attribute_Class => Class : declare |
| P : constant Entity_Id := Prefix (N); |
| |
| begin |
| Check_Restriction (No_Dispatch, N); |
| Check_Either_E0_Or_E1; |
| |
| -- If we have an expression present, then really this is a conversion |
| -- and the tree must be reformed into a proper conversion. This is a |
| -- Replace rather than a Rewrite, because the original tree is junk. |
| -- If expression is overloaded, propagate interpretations to new one. |
| |
| if Present (E1) then |
| Replace (N, |
| Make_Type_Conversion (Loc, |
| Subtype_Mark => |
| Make_Attribute_Reference (Loc, |
| Prefix => P, |
| Attribute_Name => Name_Class), |
| Expression => Relocate_Node (E1))); |
| |
| Save_Interps (E1, Expression (N)); |
| |
| if not Is_Interface (Etype (P)) then |
| Analyze (N); |
| |
| -- Ada 2005 (AI-251): In case of abstract interfaces we have to |
| -- analyze and resolve the type conversion to generate the code |
| -- that displaces the reference to the base of the object. |
| |
| else |
| Analyze_And_Resolve (N, Etype (P)); |
| end if; |
| |
| -- Otherwise we just need to find the proper type |
| |
| else |
| Find_Type (N); |
| end if; |
| |
| end Class; |
| |
| ------------------ |
| -- Code_Address -- |
| ------------------ |
| |
| when Attribute_Code_Address => |
| Check_E0; |
| |
| if Nkind (P) = N_Attribute_Reference |
| and then (Attribute_Name (P) = Name_Elab_Body |
| or else |
| Attribute_Name (P) = Name_Elab_Spec) |
| then |
| null; |
| |
| elsif not Is_Entity_Name (P) |
| or else (Ekind (Entity (P)) /= E_Function |
| and then |
| Ekind (Entity (P)) /= E_Procedure) |
| then |
| Error_Attr ("invalid prefix for % attribute", P); |
| Set_Address_Taken (Entity (P)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Address)); |
| |
| -------------------- |
| -- Component_Size -- |
| -------------------- |
| |
| when Attribute_Component_Size => |
| Check_E0; |
| Set_Etype (N, Universal_Integer); |
| |
| -- Note: unlike other array attributes, unconstrained arrays are OK |
| |
| if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then |
| null; |
| else |
| Check_Array_Type; |
| end if; |
| |
| ------------- |
| -- Compose -- |
| ------------- |
| |
| when Attribute_Compose => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, Any_Integer); |
| |
| ----------------- |
| -- Constrained -- |
| ----------------- |
| |
| when Attribute_Constrained => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| -- Case from RM J.4(2) of constrained applied to private type |
| |
| if Is_Entity_Name (P) and then Is_Type (Entity (P)) then |
| Check_Restriction (No_Obsolescent_Features, N); |
| |
| if Warn_On_Obsolescent_Feature then |
| Error_Msg_N |
| ("constrained for private type is an " & |
| "obsolescent feature ('R'M 'J.4)?", N); |
| end if; |
| |
| -- If we are within an instance, the attribute must be legal |
| -- because it was valid in the generic unit. Ditto if this is |
| -- an inlining of a function declared in an instance. |
| |
| if In_Instance |
| or else In_Inlined_Body |
| then |
| return; |
| |
| -- For sure OK if we have a real private type itself, but must |
| -- be completed, cannot apply Constrained to incomplete type. |
| |
| elsif Is_Private_Type (Entity (P)) then |
| |
| -- Note: this is one of the Annex J features that does not |
| -- generate a warning from -gnatwj, since in fact it seems |
| -- very useful, and is used in the GNAT runtime. |
| |
| Check_Not_Incomplete_Type; |
| return; |
| end if; |
| |
| -- Normal (non-obsolescent case) of application to object of |
| -- a discriminated type. |
| |
| else |
| Check_Object_Reference (P); |
| |
| -- If N does not come from source, then we allow the |
| -- the attribute prefix to be of a private type whose |
| -- full type has discriminants. This occurs in cases |
| -- involving expanded calls to stream attributes. |
| |
| if not Comes_From_Source (N) then |
| P_Type := Underlying_Type (P_Type); |
| end if; |
| |
| -- Must have discriminants or be an access type designating |
| -- a type with discriminants. If it is a classwide type is |
| -- has unknown discriminants. |
| |
| if Has_Discriminants (P_Type) |
| or else Has_Unknown_Discriminants (P_Type) |
| or else |
| (Is_Access_Type (P_Type) |
| and then Has_Discriminants (Designated_Type (P_Type))) |
| then |
| return; |
| |
| -- Also allow an object of a generic type if extensions allowed |
| -- and allow this for any type at all. |
| |
| elsif (Is_Generic_Type (P_Type) |
| or else Is_Generic_Actual_Type (P_Type)) |
| and then Extensions_Allowed |
| then |
| return; |
| end if; |
| end if; |
| |
| -- Fall through if bad prefix |
| |
| Error_Attr |
| ("prefix of % attribute must be object of discriminated type", P); |
| |
| --------------- |
| -- Copy_Sign -- |
| --------------- |
| |
| when Attribute_Copy_Sign => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| |
| ----------- |
| -- Count -- |
| ----------- |
| |
| when Attribute_Count => Count : |
| declare |
| Ent : Entity_Id; |
| S : Entity_Id; |
| Tsk : Entity_Id; |
| |
| begin |
| Check_E0; |
| |
| if Nkind (P) = N_Identifier |
| or else Nkind (P) = N_Expanded_Name |
| then |
| Ent := Entity (P); |
| |
| if Ekind (Ent) /= E_Entry then |
| Error_Attr ("invalid entry name", N); |
| end if; |
| |
| elsif Nkind (P) = N_Indexed_Component then |
| if not Is_Entity_Name (Prefix (P)) |
| or else No (Entity (Prefix (P))) |
| or else Ekind (Entity (Prefix (P))) /= E_Entry_Family |
| then |
| if Nkind (Prefix (P)) = N_Selected_Component |
| and then Present (Entity (Selector_Name (Prefix (P)))) |
| and then Ekind (Entity (Selector_Name (Prefix (P)))) = |
| E_Entry_Family |
| then |
| Error_Attr |
| ("attribute % must apply to entry of current task", P); |
| |
| else |
| Error_Attr ("invalid entry family name", P); |
| end if; |
| return; |
| |
| else |
| Ent := Entity (Prefix (P)); |
| end if; |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Present (Entity (Selector_Name (P))) |
| and then Ekind (Entity (Selector_Name (P))) = E_Entry |
| then |
| Error_Attr |
| ("attribute % must apply to entry of current task", P); |
| |
| else |
| Error_Attr ("invalid entry name", N); |
| return; |
| end if; |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| S := Scope_Stack.Table (J).Entity; |
| |
| if S = Scope (Ent) then |
| if Nkind (P) = N_Expanded_Name then |
| Tsk := Entity (Prefix (P)); |
| |
| -- The prefix denotes either the task type, or else a |
| -- single task whose task type is being analyzed. |
| |
| if (Is_Type (Tsk) |
| and then Tsk = S) |
| |
| or else (not Is_Type (Tsk) |
| and then Etype (Tsk) = S |
| and then not (Comes_From_Source (S))) |
| then |
| null; |
| else |
| Error_Attr |
| ("Attribute % must apply to entry of current task", N); |
| end if; |
| end if; |
| |
| exit; |
| |
| elsif Ekind (Scope (Ent)) in Task_Kind |
| and then Ekind (S) /= E_Loop |
| and then Ekind (S) /= E_Block |
| and then Ekind (S) /= E_Entry |
| and then Ekind (S) /= E_Entry_Family |
| then |
| Error_Attr ("Attribute % cannot appear in inner unit", N); |
| |
| elsif Ekind (Scope (Ent)) = E_Protected_Type |
| and then not Has_Completion (Scope (Ent)) |
| then |
| Error_Attr ("attribute % can only be used inside body", N); |
| end if; |
| end loop; |
| |
| if Is_Overloaded (P) then |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (P, Index, It); |
| |
| while Present (It.Nam) loop |
| if It.Nam = Ent then |
| null; |
| |
| -- Ada 2005 (AI-345): Do not consider primitive entry |
| -- wrappers generated for task or protected types. |
| |
| elsif Ada_Version >= Ada_05 |
| and then not Comes_From_Source (It.Nam) |
| then |
| null; |
| |
| else |
| Error_Attr ("ambiguous entry name", N); |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| end Count; |
| |
| ----------------------- |
| -- Default_Bit_Order -- |
| ----------------------- |
| |
| when Attribute_Default_Bit_Order => Default_Bit_Order : |
| begin |
| Check_Standard_Prefix; |
| Check_E0; |
| |
| if Bytes_Big_Endian then |
| Rewrite (N, |
| Make_Integer_Literal (Loc, False_Value)); |
| else |
| Rewrite (N, |
| Make_Integer_Literal (Loc, True_Value)); |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| Set_Is_Static_Expression (N); |
| end Default_Bit_Order; |
| |
| -------------- |
| -- Definite -- |
| -------------- |
| |
| when Attribute_Definite => |
| Legal_Formal_Attribute; |
| |
| ----------- |
| -- Delta -- |
| ----------- |
| |
| when Attribute_Delta => |
| Check_Fixed_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ------------ |
| -- Denorm -- |
| ------------ |
| |
| when Attribute_Denorm => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------ |
| -- Digits -- |
| ------------ |
| |
| when Attribute_Digits => |
| Check_E0; |
| Check_Type; |
| |
| if not Is_Floating_Point_Type (P_Type) |
| and then not Is_Decimal_Fixed_Point_Type (P_Type) |
| then |
| Error_Attr |
| ("prefix of % attribute must be float or decimal type", P); |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Elab_Body -- |
| --------------- |
| |
| -- Also handles processing for Elab_Spec |
| |
| when Attribute_Elab_Body | Attribute_Elab_Spec => |
| Check_E0; |
| Check_Unit_Name (P); |
| Set_Etype (N, Standard_Void_Type); |
| |
| -- We have to manually call the expander in this case to get |
| -- the necessary expansion (normally attributes that return |
| -- entities are not expanded). |
| |
| Expand (N); |
| |
| --------------- |
| -- Elab_Spec -- |
| --------------- |
| |
| -- Shares processing with Elab_Body |
| |
| ---------------- |
| -- Elaborated -- |
| ---------------- |
| |
| when Attribute_Elaborated => |
| Check_E0; |
| Check_Library_Unit; |
| Set_Etype (N, Standard_Boolean); |
| |
| ---------- |
| -- Emax -- |
| ---------- |
| |
| when Attribute_Emax => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Enum_Rep -- |
| -------------- |
| |
| when Attribute_Enum_Rep => Enum_Rep : declare |
| begin |
| if Present (E1) then |
| Check_E1; |
| Check_Discrete_Type; |
| Resolve (E1, P_Base_Type); |
| |
| else |
| if not Is_Entity_Name (P) |
| or else (not Is_Object (Entity (P)) |
| and then |
| Ekind (Entity (P)) /= E_Enumeration_Literal) |
| then |
| Error_Attr |
| ("prefix of %attribute must be " & |
| "discrete type/object or enum literal", P); |
| end if; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| end Enum_Rep; |
| |
| ------------- |
| -- Epsilon -- |
| ------------- |
| |
| when Attribute_Epsilon => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| -------------- |
| -- Exponent -- |
| -------------- |
| |
| when Attribute_Exponent => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, Universal_Integer); |
| Resolve (E1, P_Base_Type); |
| |
| ------------------ |
| -- External_Tag -- |
| ------------------ |
| |
| when Attribute_External_Tag => |
| Check_E0; |
| Check_Type; |
| |
| Set_Etype (N, Standard_String); |
| |
| if not Is_Tagged_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be tagged", P); |
| end if; |
| |
| ----------- |
| -- First -- |
| ----------- |
| |
| when Attribute_First => |
| Check_Array_Or_Scalar_Type; |
| |
| --------------- |
| -- First_Bit -- |
| --------------- |
| |
| when Attribute_First_Bit => |
| Check_Component; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------- |
| -- Fixed_Value -- |
| ----------------- |
| |
| when Attribute_Fixed_Value => |
| Check_E1; |
| Check_Fixed_Point_Type; |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| |
| ----------- |
| -- Floor -- |
| ----------- |
| |
| when Attribute_Floor => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ---------- |
| -- Fore -- |
| ---------- |
| |
| when Attribute_Fore => |
| Check_Fixed_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Fraction -- |
| -------------- |
| |
| when Attribute_Fraction => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ----------------------- |
| -- Has_Access_Values -- |
| ----------------------- |
| |
| when Attribute_Has_Access_Values => |
| Check_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ----------------------- |
| -- Has_Discriminants -- |
| ----------------------- |
| |
| when Attribute_Has_Discriminants => |
| Legal_Formal_Attribute; |
| |
| -------------- |
| -- Identity -- |
| -------------- |
| |
| when Attribute_Identity => |
| Check_E0; |
| Analyze (P); |
| |
| if Etype (P) = Standard_Exception_Type then |
| Set_Etype (N, RTE (RE_Exception_Id)); |
| |
| -- Ada 2005 (AI-345): Attribute 'Identity may be applied to |
| -- task interface class-wide types. |
| |
| elsif Is_Task_Type (Etype (P)) |
| or else (Is_Access_Type (Etype (P)) |
| and then Is_Task_Type (Designated_Type (Etype (P)))) |
| or else (Ada_Version >= Ada_05 |
| and then Ekind (Etype (P)) = E_Class_Wide_Type |
| and then Is_Interface (Etype (P)) |
| and then Is_Task_Interface (Etype (P))) |
| then |
| Resolve (P); |
| Set_Etype (N, RTE (RO_AT_Task_Id)); |
| |
| else |
| if Ada_Version >= Ada_05 then |
| Error_Attr ("prefix of % attribute must be an exception, a " |
| & "task or a task interface class-wide object", P); |
| else |
| Error_Attr ("prefix of % attribute must be a task or an " |
| & "exception", P); |
| end if; |
| end if; |
| |
| ----------- |
| -- Image -- |
| ----------- |
| |
| when Attribute_Image => Image : |
| begin |
| Set_Etype (N, Standard_String); |
| Check_Scalar_Type; |
| |
| if Is_Real_Type (P_Type) then |
| if Ada_Version = Ada_83 and then Comes_From_Source (N) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("(Ada 83) % attribute not allowed for real types", N); |
| end if; |
| end if; |
| |
| if Is_Enumeration_Type (P_Type) then |
| Check_Restriction (No_Enumeration_Maps, N); |
| end if; |
| |
| Check_E1; |
| Resolve (E1, P_Base_Type); |
| Check_Enum_Image; |
| Validate_Non_Static_Attribute_Function_Call; |
| end Image; |
| |
| --------- |
| -- Img -- |
| --------- |
| |
| when Attribute_Img => Img : |
| begin |
| Set_Etype (N, Standard_String); |
| |
| if not Is_Scalar_Type (P_Type) |
| or else (Is_Entity_Name (P) and then Is_Type (Entity (P))) |
| then |
| Error_Attr |
| ("prefix of % attribute must be scalar object name", N); |
| end if; |
| |
| Check_Enum_Image; |
| end Img; |
| |
| ----------- |
| -- Input -- |
| ----------- |
| |
| when Attribute_Input => |
| Check_E1; |
| Check_Stream_Attribute (TSS_Stream_Input); |
| Set_Etype (N, P_Base_Type); |
| |
| ------------------- |
| -- Integer_Value -- |
| ------------------- |
| |
| when Attribute_Integer_Value => |
| Check_E1; |
| Check_Integer_Type; |
| Resolve (E1, Any_Fixed); |
| Set_Etype (N, P_Base_Type); |
| |
| ----------- |
| -- Large -- |
| ----------- |
| |
| when Attribute_Large => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| ---------- |
| -- Last -- |
| ---------- |
| |
| when Attribute_Last => |
| Check_Array_Or_Scalar_Type; |
| |
| -------------- |
| -- Last_Bit -- |
| -------------- |
| |
| when Attribute_Last_Bit => |
| Check_Component; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------ |
| -- Leading_Part -- |
| ------------------ |
| |
| when Attribute_Leading_Part => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, Any_Integer); |
| |
| ------------ |
| -- Length -- |
| ------------ |
| |
| when Attribute_Length => |
| Check_Array_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------- |
| -- Machine -- |
| ------------- |
| |
| when Attribute_Machine => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ------------------ |
| -- Machine_Emax -- |
| ------------------ |
| |
| when Attribute_Machine_Emax => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------ |
| -- Machine_Emin -- |
| ------------------ |
| |
| when Attribute_Machine_Emin => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------------- |
| -- Machine_Mantissa -- |
| ---------------------- |
| |
| when Attribute_Machine_Mantissa => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------------- |
| -- Machine_Overflows -- |
| ----------------------- |
| |
| when Attribute_Machine_Overflows => |
| Check_Real_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------- |
| -- Machine_Radix -- |
| ------------------- |
| |
| when Attribute_Machine_Radix => |
| Check_Real_Type; |
| Check_E0; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------------- |
| -- Machine_Rounding -- |
| ---------------------- |
| |
| when Attribute_Machine_Rounding => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| -------------------- |
| -- Machine_Rounds -- |
| -------------------- |
| |
| when Attribute_Machine_Rounds => |
| Check_Real_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------ |
| -- Machine_Size -- |
| ------------------ |
| |
| when Attribute_Machine_Size => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Mantissa -- |
| -------------- |
| |
| when Attribute_Mantissa => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------- |
| -- Max -- |
| --------- |
| |
| when Attribute_Max => |
| Check_E2; |
| Check_Scalar_Type; |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| ---------------------------------- |
| -- Max_Size_In_Storage_Elements -- |
| ---------------------------------- |
| |
| when Attribute_Max_Size_In_Storage_Elements => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------------- |
| -- Maximum_Alignment -- |
| ----------------------- |
| |
| when Attribute_Maximum_Alignment => |
| Standard_Attribute (Ttypes.Maximum_Alignment); |
| |
| -------------------- |
| -- Mechanism_Code -- |
| -------------------- |
| |
| when Attribute_Mechanism_Code => |
| if not Is_Entity_Name (P) |
| or else not Is_Subprogram (Entity (P)) |
| then |
| Error_Attr ("prefix of % attribute must be subprogram", P); |
| end if; |
| |
| Check_Either_E0_Or_E1; |
| |
| if Present (E1) then |
| Resolve (E1, Any_Integer); |
| Set_Etype (E1, Standard_Integer); |
| |
| if not Is_Static_Expression (E1) then |
| Flag_Non_Static_Expr |
| ("expression for parameter number must be static!", E1); |
| Error_Attr; |
| |
| elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P)) |
| or else UI_To_Int (Intval (E1)) < 0 |
| then |
| Error_Attr ("invalid parameter number for %attribute", E1); |
| end if; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| --------- |
| -- Min -- |
| --------- |
| |
| when Attribute_Min => |
| Check_E2; |
| Check_Scalar_Type; |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| --------- |
| -- Mod -- |
| --------- |
| |
| when Attribute_Mod => |
| |
| -- Note: this attribute is only allowed in Ada 2005 mode, but |
| -- we do not need to test that here, since Mod is only recognized |
| -- as an attribute name in Ada 2005 mode during the parse. |
| |
| Check_E1; |
| Check_Modular_Integer_Type; |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| |
| ----------- |
| -- Model -- |
| ----------- |
| |
| when Attribute_Model => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ---------------- |
| -- Model_Emin -- |
| ---------------- |
| |
| when Attribute_Model_Emin => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------- |
| -- Model_Epsilon -- |
| ------------------- |
| |
| when Attribute_Model_Epsilon => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| -------------------- |
| -- Model_Mantissa -- |
| -------------------- |
| |
| when Attribute_Model_Mantissa => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------- |
| -- Model_Small -- |
| ----------------- |
| |
| when Attribute_Model_Small => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ------------- |
| -- Modulus -- |
| ------------- |
| |
| when Attribute_Modulus => |
| Check_E0; |
| Check_Modular_Integer_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------------- |
| -- Null_Parameter -- |
| -------------------- |
| |
| when Attribute_Null_Parameter => Null_Parameter : declare |
| Parnt : constant Node_Id := Parent (N); |
| GParnt : constant Node_Id := Parent (Parnt); |
| |
| procedure Bad_Null_Parameter (Msg : String); |
| -- Used if bad Null parameter attribute node is found. Issues |
| -- given error message, and also sets the type to Any_Type to |
| -- avoid blowups later on from dealing with a junk node. |
| |
| procedure Must_Be_Imported (Proc_Ent : Entity_Id); |
| -- Called to check that Proc_Ent is imported subprogram |
| |
| ------------------------ |
| -- Bad_Null_Parameter -- |
| ------------------------ |
| |
| procedure Bad_Null_Parameter (Msg : String) is |
| begin |
| Error_Msg_N (Msg, N); |
| Set_Etype (N, Any_Type); |
| end Bad_Null_Parameter; |
| |
| ---------------------- |
| -- Must_Be_Imported -- |
| ---------------------- |
| |
| procedure Must_Be_Imported (Proc_Ent : Entity_Id) is |
| Pent : Entity_Id := Proc_Ent; |
| |
| begin |
| while Present (Alias (Pent)) loop |
| Pent := Alias (Pent); |
| end loop; |
| |
| -- Ignore check if procedure not frozen yet (we will get |
| -- another chance when the default parameter is reanalyzed) |
| |
| if not Is_Frozen (Pent) then |
| return; |
| |
| elsif not Is_Imported (Pent) then |
| Bad_Null_Parameter |
| ("Null_Parameter can only be used with imported subprogram"); |
| |
| else |
| return; |
| end if; |
| end Must_Be_Imported; |
| |
| -- Start of processing for Null_Parameter |
| |
| begin |
| Check_Type; |
| Check_E0; |
| Set_Etype (N, P_Type); |
| |
| -- Case of attribute used as default expression |
| |
| if Nkind (Parnt) = N_Parameter_Specification then |
| Must_Be_Imported (Defining_Entity (GParnt)); |
| |
| -- Case of attribute used as actual for subprogram (positional) |
| |
| elsif (Nkind (Parnt) = N_Procedure_Call_Statement |
| or else |
| Nkind (Parnt) = N_Function_Call) |
| and then Is_Entity_Name (Name (Parnt)) |
| then |
| Must_Be_Imported (Entity (Name (Parnt))); |
| |
| -- Case of attribute used as actual for subprogram (named) |
| |
| elsif Nkind (Parnt) = N_Parameter_Association |
| and then (Nkind (GParnt) = N_Procedure_Call_Statement |
| or else |
| Nkind (GParnt) = N_Function_Call) |
| and then Is_Entity_Name (Name (GParnt)) |
| then |
| Must_Be_Imported (Entity (Name (GParnt))); |
| |
| -- Not an allowed case |
| |
| else |
| Bad_Null_Parameter |
| ("Null_Parameter must be actual or default parameter"); |
| end if; |
| |
| end Null_Parameter; |
| |
| ----------------- |
| -- Object_Size -- |
| ----------------- |
| |
| when Attribute_Object_Size => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------ |
| -- Output -- |
| ------------ |
| |
| when Attribute_Output => |
| Check_E2; |
| Check_Stream_Attribute (TSS_Stream_Output); |
| Set_Etype (N, Standard_Void_Type); |
| Resolve (N, Standard_Void_Type); |
| |
| ------------------ |
| -- Partition_ID -- |
| ------------------ |
| |
| when Attribute_Partition_ID => |
| Check_E0; |
| |
| if P_Type /= Any_Type then |
| if not Is_Library_Level_Entity (Entity (P)) then |
| Error_Attr |
| ("prefix of % attribute must be library-level entity", P); |
| |
| -- The defining entity of prefix should not be declared inside |
| -- a Pure unit. RM E.1(8). |
| -- The Is_Pure flag has been set during declaration. |
| |
| elsif Is_Entity_Name (P) |
| and then Is_Pure (Entity (P)) |
| then |
| Error_Attr |
| ("prefix of % attribute must not be declared pure", P); |
| end if; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------------- |
| -- Passed_By_Reference -- |
| ------------------------- |
| |
| when Attribute_Passed_By_Reference => |
| Check_E0; |
| Check_Type; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------ |
| -- Pool_Address -- |
| ------------------ |
| |
| when Attribute_Pool_Address => |
| Check_E0; |
| Set_Etype (N, RTE (RE_Address)); |
| |
| --------- |
| -- Pos -- |
| --------- |
| |
| when Attribute_Pos => |
| Check_Discrete_Type; |
| Check_E1; |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Position -- |
| -------------- |
| |
| when Attribute_Position => |
| Check_Component; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------- |
| -- Pred -- |
| ---------- |
| |
| when Attribute_Pred => |
| Check_Scalar_Type; |
| Check_E1; |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| -- Nothing to do for real type case |
| |
| if Is_Real_Type (P_Type) then |
| null; |
| |
| -- If not modular type, test for overflow check required |
| |
| else |
| if not Is_Modular_Integer_Type (P_Type) |
| and then not Range_Checks_Suppressed (P_Base_Type) |
| then |
| Enable_Range_Check (E1); |
| end if; |
| end if; |
| |
| ----------- |
| -- Range -- |
| ----------- |
| |
| when Attribute_Range => |
| Check_Array_Or_Scalar_Type; |
| |
| if Ada_Version = Ada_83 |
| and then Is_Scalar_Type (P_Type) |
| and then Comes_From_Source (N) |
| then |
| Error_Attr |
| ("(Ada 83) % attribute not allowed for scalar type", P); |
| end if; |
| |
| ------------------ |
| -- Range_Length -- |
| ------------------ |
| |
| when Attribute_Range_Length => |
| Check_Discrete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------- |
| -- Read -- |
| ---------- |
| |
| when Attribute_Read => |
| Check_E2; |
| Check_Stream_Attribute (TSS_Stream_Read); |
| Set_Etype (N, Standard_Void_Type); |
| Resolve (N, Standard_Void_Type); |
| Note_Possible_Modification (E2); |
| |
| --------------- |
| -- Remainder -- |
| --------------- |
| |
| when Attribute_Remainder => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| |
| ----------- |
| -- Round -- |
| ----------- |
| |
| when Attribute_Round => |
| Check_E1; |
| Check_Decimal_Fixed_Point_Type; |
| Set_Etype (N, P_Base_Type); |
| |
| -- Because the context is universal_real (3.5.10(12)) it is a legal |
| -- context for a universal fixed expression. This is the only |
| -- attribute whose functional description involves U_R. |
| |
| if Etype (E1) = Universal_Fixed then |
| declare |
| Conv : constant Node_Id := Make_Type_Conversion (Loc, |
| Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc), |
| Expression => Relocate_Node (E1)); |
| |
| begin |
| Rewrite (E1, Conv); |
| Analyze (E1); |
| end; |
| end if; |
| |
| Resolve (E1, Any_Real); |
| |
| -------------- |
| -- Rounding -- |
| -------------- |
| |
| when Attribute_Rounding => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| --------------- |
| -- Safe_Emax -- |
| --------------- |
| |
| when Attribute_Safe_Emax => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------- |
| -- Safe_First -- |
| ---------------- |
| |
| when Attribute_Safe_First => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ---------------- |
| -- Safe_Large -- |
| ---------------- |
| |
| when Attribute_Safe_Large => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| --------------- |
| -- Safe_Last -- |
| --------------- |
| |
| when Attribute_Safe_Last => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ---------------- |
| -- Safe_Small -- |
| ---------------- |
| |
| when Attribute_Safe_Small => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| ----------- |
| -- Scale -- |
| ----------- |
| |
| when Attribute_Scale => |
| Check_E0; |
| Check_Decimal_Fixed_Point_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------- |
| -- Scaling -- |
| ------------- |
| |
| when Attribute_Scaling => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ------------------ |
| -- Signed_Zeros -- |
| ------------------ |
| |
| when Attribute_Signed_Zeros => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ---------- |
| -- Size -- |
| ---------- |
| |
| when Attribute_Size | Attribute_VADS_Size => |
| Check_E0; |
| |
| -- If prefix is parameterless function call, rewrite and resolve |
| -- as such. |
| |
| if Is_Entity_Name (P) |
| and then Ekind (Entity (P)) = E_Function |
| then |
| Resolve (P); |
| |
| -- Similar processing for a protected function call |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Ekind (Entity (Selector_Name (P))) = E_Function |
| then |
| Resolve (P); |
| end if; |
| |
| if Is_Object_Reference (P) then |
| Check_Object_Reference (P); |
| |
| elsif Is_Entity_Name (P) |
| and then (Is_Type (Entity (P)) |
| or else Ekind (Entity (P)) = E_Enumeration_Literal) |
| then |
| null; |
| |
| elsif Nkind (P) = N_Type_Conversion |
| and then not Comes_From_Source (P) |
| then |
| null; |
| |
| else |
| Error_Attr ("invalid prefix for % attribute", P); |
| end if; |
| |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------- |
| -- Small -- |
| ----------- |
| |
| when Attribute_Small => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| ------------------ |
| -- Storage_Pool -- |
| ------------------ |
| |
| when Attribute_Storage_Pool => |
| if Is_Access_Type (P_Type) then |
| Check_E0; |
| |
| -- Set appropriate entity |
| |
| if Present (Associated_Storage_Pool (Root_Type (P_Type))) then |
| Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type))); |
| else |
| Set_Entity (N, RTE (RE_Global_Pool_Object)); |
| end if; |
| |
| Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool))); |
| |
| -- Validate_Remote_Access_To_Class_Wide_Type for attribute |
| -- Storage_Pool since this attribute is not defined for such |
| -- types (RM E.2.3(22)). |
| |
| Validate_Remote_Access_To_Class_Wide_Type (N); |
| |
| else |
| Error_Attr ("prefix of % attribute must be access type", P); |
| end if; |
| |
| ------------------ |
| -- Storage_Size -- |
| ------------------ |
| |
| when Attribute_Storage_Size => |
| |
| if Is_Task_Type (P_Type) then |
| Check_E0; |
| Set_Etype (N, Universal_Integer); |
| |
| elsif Is_Access_Type (P_Type) then |
| if Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| Check_E0; |
| Check_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -- Validate_Remote_Access_To_Class_Wide_Type for attribute |
| -- Storage_Size since this attribute is not defined for |
| -- such types (RM E.2.3(22)). |
| |
| Validate_Remote_Access_To_Class_Wide_Type (N); |
| |
| -- The prefix is allowed to be an implicit dereference |
| -- of an access value designating a task. |
| |
| else |
| Check_E0; |
| Check_Task_Prefix; |
| Set_Etype (N, Universal_Integer); |
| end if; |
| |
| else |
| Error_Attr |
| ("prefix of % attribute must be access or task type", P); |
| end if; |
| |
| ------------------ |
| -- Storage_Unit -- |
| ------------------ |
| |
| when Attribute_Storage_Unit => |
| Standard_Attribute (Ttypes.System_Storage_Unit); |
| |
| ----------------- |
| -- Stream_Size -- |
| ----------------- |
| |
| when Attribute_Stream_Size => |
| Check_E0; |
| Check_Type; |
| |
| if Is_Entity_Name (P) |
| and then Is_Elementary_Type (Entity (P)) |
| then |
| Set_Etype (N, Universal_Integer); |
| else |
| Error_Attr ("invalid prefix for % attribute", P); |
| end if; |
| |
| ---------- |
| -- Succ -- |
| ---------- |
| |
| when Attribute_Succ => |
| Check_Scalar_Type; |
| Check_E1; |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| -- Nothing to do for real type case |
| |
| if Is_Real_Type (P_Type) then |
| null; |
| |
| -- If not modular type, test for overflow check required |
| |
| else |
| if not Is_Modular_Integer_Type (P_Type) |
| and then not Range_Checks_Suppressed (P_Base_Type) |
| then |
| Enable_Range_Check (E1); |
| end if; |
| end if; |
| |
| --------- |
| -- Tag -- |
| --------- |
| |
| when Attribute_Tag => |
| Check_E0; |
| Check_Dereference; |
| |
| if not Is_Tagged_Type (P_Type) then |
| Error_Attr ("prefix of % attribute must be tagged", P); |
| |
| -- Next test does not apply to generated code |
| -- why not, and what does the illegal reference mean??? |
| |
| elsif Is_Object_Reference (P) |
| and then not Is_Class_Wide_Type (P_Type) |
| and then Comes_From_Source (N) |
| then |
| Error_Attr |
| ("% attribute can only be applied to objects of class-wide type", |
| P); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Tag)); |
| |
| ----------------- |
| -- Target_Name -- |
| ----------------- |
| |
| when Attribute_Target_Name => Target_Name : declare |
| TN : constant String := Sdefault.Target_Name.all; |
| TL : Natural; |
| |
| begin |
| Check_Standard_Prefix; |
| Check_E0; |
| |
| TL := TN'Last; |
| |
| if TN (TL) = '/' or else TN (TL) = '\' then |
| TL := TL - 1; |
| end if; |
| |
| Rewrite (N, |
| Make_String_Literal (Loc, |
| Strval => TN (TN'First .. TL))); |
| Analyze_And_Resolve (N, Standard_String); |
| end Target_Name; |
| |
| ---------------- |
| -- Terminated -- |
| ---------------- |
| |
| when Attribute_Terminated => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| Check_Task_Prefix; |
| |
| ---------------- |
| -- To_Address -- |
| ---------------- |
| |
| when Attribute_To_Address => |
| Check_E1; |
| Analyze (P); |
| |
| if Nkind (P) /= N_Identifier |
| or else Chars (P) /= Name_System |
| then |
| Error_Attr ("prefix of %attribute must be System", P); |
| end if; |
| |
| Generate_Reference (RTE (RE_Address), P); |
| Analyze_And_Resolve (E1, Any_Integer); |
| Set_Etype (N, RTE (RE_Address)); |
| |
| ---------------- |
| -- Truncation -- |
| ---------------- |
| |
| when Attribute_Truncation => |
| Check_Floating_Point_Type_1; |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| ---------------- |
| -- Type_Class -- |
| ---------------- |
| |
| when Attribute_Type_Class => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, RTE (RE_Type_Class)); |
| |
| ----------------- |
| -- UET_Address -- |
| ----------------- |
| |
| when Attribute_UET_Address => |
| Check_E0; |
| Check_Unit_Name (P); |
| Set_Etype (N, RTE (RE_Address)); |
| |
| ----------------------- |
| -- Unbiased_Rounding -- |
| ----------------------- |
| |
| when Attribute_Unbiased_Rounding => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ---------------------- |
| -- Unchecked_Access -- |
| ---------------------- |
| |
| when Attribute_Unchecked_Access => |
| if Comes_From_Source (N) then |
| Check_Restriction (No_Unchecked_Access, N); |
| end if; |
| |
| Analyze_Access_Attribute; |
| |
| ------------------------- |
| -- Unconstrained_Array -- |
| ------------------------- |
| |
| when Attribute_Unconstrained_Array => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------------------ |
| -- Universal_Literal_String -- |
| ------------------------------ |
| |
| -- This is a GNAT specific attribute whose prefix must be a named |
| -- number where the expression is either a single numeric literal, |
| -- or a numeric literal immediately preceded by a minus sign. The |
| -- result is equivalent to a string literal containing the text of |
| -- the literal as it appeared in the source program with a possible |
| -- leading minus sign. |
| |
| when Attribute_Universal_Literal_String => Universal_Literal_String : |
| begin |
| Check_E0; |
| |
| if not Is_Entity_Name (P) |
| or else Ekind (Entity (P)) not in Named_Kind |
| then |
| Error_Attr ("prefix for % attribute must be named number", P); |
| |
| else |
| declare |
| Expr : Node_Id; |
| Negative : Boolean; |
| S : Source_Ptr; |
| Src : Source_Buffer_Ptr; |
| |
| begin |
| Expr := Original_Node (Expression (Parent (Entity (P)))); |
| |
| if Nkind (Expr) = N_Op_Minus then |
| Negative := True; |
| Expr := Original_Node (Right_Opnd (Expr)); |
| else |
| Negative := False; |
| end if; |
| |
| if Nkind (Expr) /= N_Integer_Literal |
| and then Nkind (Expr) /= N_Real_Literal |
| then |
| Error_Attr |
| ("named number for % attribute must be simple literal", N); |
| end if; |
| |
| -- Build string literal corresponding to source literal text |
| |
| Start_String; |
| |
| if Negative then |
| Store_String_Char (Get_Char_Code ('-')); |
| end if; |
| |
| S := Sloc (Expr); |
| Src := Source_Text (Get_Source_File_Index (S)); |
| |
| while Src (S) /= ';' and then Src (S) /= ' ' loop |
| Store_String_Char (Get_Char_Code (Src (S))); |
| S := S + 1; |
| end loop; |
| |
| -- Now we rewrite the attribute with the string literal |
| |
| Rewrite (N, |
| Make_String_Literal (Loc, End_String)); |
| Analyze (N); |
| end; |
| end if; |
| end Universal_Literal_String; |
| |
| ------------------------- |
| -- Unrestricted_Access -- |
| ------------------------- |
| |
| -- This is a GNAT specific attribute which is like Access except that |
| -- all scope checks and checks for aliased views are omitted. |
| |
| when Attribute_Unrestricted_Access => |
| if Comes_From_Source (N) then |
| Check_Restriction (No_Unchecked_Access, N); |
| end if; |
| |
| if Is_Entity_Name (P) then |
| Set_Address_Taken (Entity (P)); |
| end if; |
| |
| Analyze_Access_Attribute; |
| |
| --------- |
| -- Val -- |
| --------- |
| |
| when Attribute_Val => Val : declare |
| begin |
| Check_E1; |
| Check_Discrete_Type; |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| |
| -- Note, we need a range check in general, but we wait for the |
| -- Resolve call to do this, since we want to let Eval_Attribute |
| -- have a chance to find an static illegality first! |
| end Val; |
| |
| ----------- |
| -- Valid -- |
| ----------- |
| |
| when Attribute_Valid => |
| Check_E0; |
| |
| -- Ignore check for object if we have a 'Valid reference generated |
| -- by the expanded code, since in some cases valid checks can occur |
| -- on items that are names, but are not objects (e.g. attributes). |
| |
| if Comes_From_Source (N) then |
| Check_Object_Reference (P); |
| end if; |
| |
| if not Is_Scalar_Type (P_Type) then |
| Error_Attr ("object for % attribute must be of scalar type", P); |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| |
| ----------- |
| -- Value -- |
| ----------- |
| |
| when Attribute_Value => Value : |
| begin |
| Check_E1; |
| Check_Scalar_Type; |
| |
| if Is_Enumeration_Type (P_Type) then |
| Check_Restriction (No_Enumeration_Maps, N); |
| end if; |
| |
| -- Set Etype before resolving expression because expansion of |
| -- expression may require enclosing type. Note that the type |
| -- returned by 'Value is the base type of the prefix type. |
| |
| Set_Etype (N, P_Base_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| end Value; |
| |
| ---------------- |
| -- Value_Size -- |
| ---------------- |
| |
| when Attribute_Value_Size => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------- |
| -- Version -- |
| ------------- |
| |
| when Attribute_Version => |
| Check_E0; |
| Check_Program_Unit; |
| Set_Etype (N, RTE (RE_Version_String)); |
| |
| ------------------ |
| -- Wchar_T_Size -- |
| ------------------ |
| |
| when Attribute_Wchar_T_Size => |
| Standard_Attribute (Interfaces_Wchar_T_Size); |
| |
| ---------------- |
| -- Wide_Image -- |
| ---------------- |
| |
| when Attribute_Wide_Image => Wide_Image : |
| begin |
| Check_Scalar_Type; |
| Set_Etype (N, Standard_Wide_String); |
| Check_E1; |
| Resolve (E1, P_Base_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| end Wide_Image; |
| |
| --------------------- |
| -- Wide_Wide_Image -- |
| --------------------- |
| |
| when Attribute_Wide_Wide_Image => Wide_Wide_Image : |
| begin |
| Check_Scalar_Type; |
| Set_Etype (N, Standard_Wide_Wide_String); |
| Check_E1; |
| Resolve (E1, P_Base_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| end Wide_Wide_Image; |
| |
| ---------------- |
| -- Wide_Value -- |
| ---------------- |
| |
| when Attribute_Wide_Value => Wide_Value : |
| begin |
| Check_E1; |
| Check_Scalar_Type; |
| |
| -- Set Etype before resolving expression because expansion |
| -- of expression may require enclosing type. |
| |
| Set_Etype (N, P_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| end Wide_Value; |
| |
| --------------------- |
| -- Wide_Wide_Value -- |
| --------------------- |
| |
| when Attribute_Wide_Wide_Value => Wide_Wide_Value : |
| begin |
| Check_E1; |
| Check_Scalar_Type; |
| |
| -- Set Etype before resolving expression because expansion |
| -- of expression may require enclosing type. |
| |
| Set_Etype (N, P_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| end Wide_Wide_Value; |
| |
| --------------------- |
| -- Wide_Wide_Width -- |
| --------------------- |
| |
| when Attribute_Wide_Wide_Width => |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------- |
| -- Wide_Width -- |
| ---------------- |
| |
| when Attribute_Wide_Width => |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------- |
| -- Width -- |
| ----------- |
| |
| when Attribute_Width => |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Word_Size -- |
| --------------- |
| |
| when Attribute_Word_Size => |
| Standard_Attribute (System_Word_Size); |
| |
| ----------- |
| -- Write -- |
| ----------- |
| |
| when Attribute_Write => |
| Check_E2; |
| Check_Stream_Attribute (TSS_Stream_Write); |
| Set_Etype (N, Standard_Void_Type); |
| Resolve (N, Standard_Void_Type); |
| |
| end case; |
| |
| -- All errors raise Bad_Attribute, so that we get out before any further |
| -- damage occurs when an error is detected (for example, if we check for |
| -- one attribute expression, and the check succeeds, we want to be able |
| -- to proceed securely assuming that an expression is in fact present. |
| |
| -- Note: we set the attribute analyzed in this case to prevent any |
| -- attempt at reanalysis which could generate spurious error msgs. |
| |
| exception |
| when Bad_Attribute => |
| Set_Analyzed (N); |
| Set_Etype (N, Any_Type); |
| return; |
| end Analyze_Attribute; |
| |
| -------------------- |
| -- Eval_Attribute -- |
| -------------------- |
| |
| procedure Eval_Attribute (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Aname : constant Name_Id := Attribute_Name (N); |
| Id : constant Attribute_Id := Get_Attribute_Id (Aname); |
| P : constant Node_Id := Prefix (N); |
| |
| C_Type : constant Entity_Id := Etype (N); |
| -- The type imposed by the context |
| |
| E1 : Node_Id; |
| -- First expression, or Empty if none |
| |
| E2 : Node_Id; |
| -- Second expression, or Empty if none |
| |
| P_Entity : Entity_Id; |
| -- Entity denoted by prefix |
| |
| P_Type : Entity_Id; |
| -- The type of the prefix |
| |
| P_Base_Type : Entity_Id; |
| -- The base type of the prefix type |
| |
| P_Root_Type : Entity_Id; |
| -- The root type of the prefix type |
| |
| Static : Boolean; |
| -- True if the result is Static. This is set by the general processing |
| -- to true if the prefix is static, and all expressions are static. It |
| -- can be reset as processing continues for particular attributes |
| |
| Lo_Bound, Hi_Bound : Node_Id; |
| -- Expressions for low and high bounds of type or array index referenced |
| -- by First, Last, or Length attribute for array, set by Set_Bounds. |
| |
| CE_Node : Node_Id; |
| -- Constraint error node used if we have an attribute reference has |
| -- an argument that raises a constraint error. In this case we replace |
| -- the attribute with a raise constraint_error node. This is important |
| -- processing, since otherwise gigi might see an attribute which it is |
| -- unprepared to deal with. |
| |
| function Aft_Value return Nat; |
| -- Computes Aft value for current attribute prefix (used by Aft itself |
| -- and also by Width for computing the Width of a fixed point type). |
| |
| procedure Check_Expressions; |
| -- In case where the attribute is not foldable, the expressions, if |
| -- any, of the attribute, are in a non-static context. This procedure |
| -- performs the required additional checks. |
| |
| function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean; |
| -- Determines if the given type has compile time known bounds. Note |
| -- that we enter the case statement even in cases where the prefix |
| -- type does NOT have known bounds, so it is important to guard any |
| -- attempt to evaluate both bounds with a call to this function. |
| |
| procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint); |
| -- This procedure is called when the attribute N has a non-static |
| -- but compile time known value given by Val. It includes the |
| -- necessary checks for out of range values. |
| |
| procedure Float_Attribute_Universal_Integer |
| (IEEES_Val : Int; |
| IEEEL_Val : Int; |
| IEEEX_Val : Int; |
| VAXFF_Val : Int; |
| VAXDF_Val : Int; |
| VAXGF_Val : Int; |
| AAMPS_Val : Int; |
| AAMPL_Val : Int); |
| -- This procedure evaluates a float attribute with no arguments that |
| -- returns a universal integer result. The parameters give the values |
| -- for the possible floating-point root types. See ttypef for details. |
| -- The prefix type is a float type (and is thus not a generic type). |
| |
| procedure Float_Attribute_Universal_Real |
| (IEEES_Val : String; |
| IEEEL_Val : String; |
| IEEEX_Val : String; |
| VAXFF_Val : String; |
| VAXDF_Val : String; |
| VAXGF_Val : String; |
| AAMPS_Val : String; |
| AAMPL_Val : String); |
| -- This procedure evaluates a float attribute with no arguments that |
| -- returns a universal real result. The parameters give the values |
| -- required for the possible floating-point root types in string |
| -- format as real literals with a possible leading minus sign. |
| -- The prefix type is a float type (and is thus not a generic type). |
| |
| function Fore_Value return Nat; |
| -- Computes the Fore value for the current attribute prefix, which is |
| -- known to be a static fixed-point type. Used by Fore and Width. |
| |
| function Mantissa return Uint; |
| -- Returns the Mantissa value for the prefix type |
| |
| procedure Set_Bounds; |
| -- Used for First, Last and Length attributes applied to an array or |
| -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low |
| -- and high bound expressions for the index referenced by the attribute |
| -- designator (i.e. the first index if no expression is present, and |
| -- the N'th index if the value N is present as an expression). Also |
| -- used for First and Last of scalar types. Static is reset to False |
| -- if the type or index type is not statically constrained. |
| |
| function Statically_Denotes_Entity (N : Node_Id) return Boolean; |
| -- Verify that the prefix of a potentially static array attribute |
| -- satisfies the conditions of 4.9 (14). |
| |
| --------------- |
| -- Aft_Value -- |
| --------------- |
| |
| function Aft_Value return Nat is |
| Result : Nat; |
| Delta_Val : Ureal; |
| |
| begin |
| Result := 1; |
| Delta_Val := Delta_Value (P_Type); |
| |
| while Delta_Val < Ureal_Tenth loop |
| Delta_Val := Delta_Val * Ureal_10; |
| Result := Result + 1; |
| end loop; |
| |
| return Result; |
| end Aft_Value; |
| |
| ----------------------- |
| -- Check_Expressions -- |
| ----------------------- |
| |
| procedure Check_Expressions is |
| E : Node_Id := E1; |
| |
| begin |
| while Present (E) loop |
| Check_Non_Static_Context (E); |
| Next (E); |
| end loop; |
| end Check_Expressions; |
| |
| ---------------------------------- |
| -- Compile_Time_Known_Attribute -- |
| ---------------------------------- |
| |
| procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is |
| T : constant Entity_Id := Etype (N); |
| |
| begin |
| Fold_Uint (N, Val, False); |
| |
| -- Check that result is in bounds of the type if it is static |
| |
| if Is_In_Range (N, T) then |
| null; |
| |
| elsif Is_Out_Of_Range (N, T) then |
| Apply_Compile_Time_Constraint_Error |
| (N, "value not in range of}?", CE_Range_Check_Failed); |
| |
| elsif not Range_Checks_Suppressed (T) then |
| Enable_Range_Check (N); |
| |
| else |
| Set_Do_Range_Check (N, False); |
| end if; |
| end Compile_Time_Known_Attribute; |
| |
| ------------------------------- |
| -- Compile_Time_Known_Bounds -- |
| ------------------------------- |
| |
| function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is |
| begin |
| return |
| Compile_Time_Known_Value (Type_Low_Bound (Typ)) |
| and then |
| Compile_Time_Known_Value (Type_High_Bound (Typ)); |
| end Compile_Time_Known_Bounds; |
| |
| --------------------------------------- |
| -- Float_Attribute_Universal_Integer -- |
| --------------------------------------- |
| |
| procedure Float_Attribute_Universal_Integer |
| (IEEES_Val : Int; |
| IEEEL_Val : Int; |
| IEEEX_Val : Int; |
| VAXFF_Val : Int; |
| VAXDF_Val : Int; |
| VAXGF_Val : Int; |
| AAMPS_Val : Int; |
| AAMPL_Val : Int) |
| is |
| Val : Int; |
| Digs : constant Nat := UI_To_Int (Digits_Value (P_Base_Type)); |
| |
| begin |
| if Vax_Float (P_Base_Type) then |
| if Digs = VAXFF_Digits then |
| Val := VAXFF_Val; |
| elsif Digs = VAXDF_Digits then |
| Val := VAXDF_Val; |
| else pragma Assert (Digs = VAXGF_Digits); |
| Val := VAXGF_Val; |
| end if; |
| |
| elsif Is_AAMP_Float (P_Base_Type) then |
| if Digs = AAMPS_Digits then |
| Val := AAMPS_Val; |
| else pragma Assert (Digs = AAMPL_Digits); |
| Val := AAMPL_Val; |
| end if; |
| |
| else |
| if Digs = IEEES_Digits then |
| Val := IEEES_Val; |
| elsif Digs = IEEEL_Digits then |
| Val := IEEEL_Val; |
| else pragma Assert (Digs = IEEEX_Digits); |
| Val := IEEEX_Val; |
| end if; |
| end if; |
| |
| Fold_Uint (N, UI_From_Int (Val), True); |
| end Float_Attribute_Universal_Integer; |
| |
| ------------------------------------ |
| -- Float_Attribute_Universal_Real -- |
| ------------------------------------ |
| |
| procedure Float_Attribute_Universal_Real |
| (IEEES_Val : String; |
| IEEEL_Val : String; |
| IEEEX_Val : String; |
| VAXFF_Val : String; |
| VAXDF_Val : String; |
| VAXGF_Val : String; |
| AAMPS_Val : String; |
| AAMPL_Val : String) |
| is |
| Val : Node_Id; |
| Digs : constant Nat := UI_To_Int (Digits_Value (P_Base_Type)); |
| |
| begin |
| if Vax_Float (P_Base_Type) then |
| if Digs = VAXFF_Digits then |
| Val := Real_Convert (VAXFF_Val); |
| elsif Digs = VAXDF_Digits then |
| Val := Real_Convert (VAXDF_Val); |
| else pragma Assert (Digs = VAXGF_Digits); |
| Val := Real_Convert (VAXGF_Val); |
| end if; |
| |
| elsif Is_AAMP_Float (P_Base_Type) then |
| if Digs = AAMPS_Digits then |
| Val := Real_Convert (AAMPS_Val); |
| else pragma Assert (Digs = AAMPL_Digits); |
| Val := Real_Convert (AAMPL_Val); |
| end if; |
| |
| else |
| if Digs = IEEES_Digits then |
| Val := Real_Convert (IEEES_Val); |
| elsif Digs = IEEEL_Digits then |
| Val := Real_Convert (IEEEL_Val); |
| else pragma Assert (Digs = IEEEX_Digits); |
| Val := Real_Convert (IEEEX_Val); |
| end if; |
| end if; |
| |
| Set_Sloc (Val, Loc); |
| Rewrite (N, Val); |
| Set_Is_Static_Expression (N, Static); |
| Analyze_And_Resolve (N, C_Type); |
| end Float_Attribute_Universal_Real; |
| |
| ---------------- |
| -- Fore_Value -- |
| ---------------- |
| |
| -- Note that the Fore calculation is based on the actual values |
| -- of the bounds, and does not take into account possible rounding. |
| |
| function Fore_Value return Nat is |
| Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type)); |
| Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type)); |
| Small : constant Ureal := Small_Value (P_Type); |
| Lo_Real : constant Ureal := Lo * Small; |
| Hi_Real : constant Ureal := Hi * Small; |
| T : Ureal; |
| R : Nat; |
| |
| begin |
| -- Bounds are given in terms of small units, so first compute |
| -- proper values as reals. |
| |
| T := UR_Max (abs Lo_Real, abs Hi_Real); |
| R := 2; |
| |
| -- Loop to compute proper value if more than one digit required |
| |
| while T >= Ureal_10 loop |
| R := R + 1; |
| T := T / Ureal_10; |
| end loop; |
| |
| return R; |
| end Fore_Value; |
| |
| -------------- |
| -- Mantissa -- |
| -------------- |
| |
| -- Table of mantissa values accessed by function Computed using |
| -- the relation: |
| |
| -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1) |
| |
| -- where D is T'Digits (RM83 3.5.7) |
| |
| Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := ( |
| 1 => 5, |
| 2 => 8, |
| 3 => 11, |
| 4 => 15, |
| 5 => 18, |
| 6 => 21, |
| 7 => 25, |
| 8 => 28, |
| 9 => 31, |
| 10 => 35, |
| 11 => 38, |
| 12 => 41, |
| 13 => 45, |
| 14 => 48, |
| 15 => 51, |
| 16 => 55, |
| 17 => 58, |
| 18 => 61, |
| 19 => 65, |
| 20 => 68, |
| 21 => 71, |
| 22 => 75, |
| 23 => 78, |
| 24 => 81, |
| 25 => 85, |
| 26 => 88, |
| 27 => 91, |
| 28 => 95, |
| 29 => 98, |
| 30 => 101, |
| 31 => 104, |
| 32 => 108, |
| 33 => 111, |
| 34 => 114, |
| 35 => 118, |
| 36 => 121, |
| 37 => 124, |
| 38 => 128, |
| 39 => 131, |
| 40 => 134); |
| |
| function Mantissa return Uint is |
| begin |
| return |
| UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type)))); |
| end Mantissa; |
| |
| ---------------- |
| -- Set_Bounds -- |
| ---------------- |
| |
| procedure Set_Bounds is |
| Ndim : Nat; |
| Indx : Node_Id; |
| Ityp : Entity_Id; |
| |
| begin |
| -- For a string literal subtype, we have to construct the bounds. |
| -- Valid Ada code never applies attributes to string literals, but |
| -- it is convenient to allow the expander to generate attribute |
| -- references of this type (e.g. First and Last applied to a string |
| -- literal). |
| |
| -- Note that the whole point of the E_String_Literal_Subtype is to |
| -- avoid this construction of bounds, but the cases in which we |
| -- have to materialize them are rare enough that we don't worry! |
| |
| -- The low bound is simply the low bound of the base type. The |
| -- high bound is computed from the length of the string and this |
| -- low bound. |
| |
| if Ekind (P_Type) = E_String_Literal_Subtype then |
| Ityp := Etype (First_Index (Base_Type (P_Type))); |
| Lo_Bound := Type_Low_Bound (Ityp); |
| |
| Hi_Bound := |
| Make_Integer_Literal (Sloc (P), |
| Intval => |
| Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1); |
| |
| Set_Parent (Hi_Bound, P); |
| Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound)); |
| return; |
| |
| -- For non-array case, just get bounds of scalar type |
| |
| elsif Is_Scalar_Type (P_Type) then |
| Ityp := P_Type; |
| |
| -- For a fixed-point type, we must freeze to get the attributes |
| -- of the fixed-point type set now so we can reference them. |
| |
| if Is_Fixed_Point_Type (P_Type) |
| and then not Is_Frozen (Base_Type (P_Type)) |
| and then Compile_Time_Known_Value (Type_Low_Bound (P_Type)) |
| and then Compile_Time_Known_Value (Type_High_Bound (P_Type)) |
| then |
| Freeze_Fixed_Point_Type (Base_Type (P_Type)); |
| end if; |
| |
| -- For array case, get type of proper index |
| |
| else |
| if No (E1) then |
| Ndim := 1; |
| else |
| Ndim := UI_To_Int (Expr_Value (E1)); |
| end if; |
| |
| Indx := First_Index (P_Type); |
| for J in 1 .. Ndim - 1 loop |
| Next_Index (Indx); |
| end loop; |
| |
| -- If no index type, get out (some other error occurred, and |
| -- we don't have enough information to complete the job!) |
| |
| if No (Indx) then |
| Lo_Bound := Error; |
| Hi_Bound := Error; |
| return; |
| end if; |
| |
| Ityp := Etype (Indx); |
| end if; |
| |
| -- A discrete range in an index constraint is allowed to be a |
| -- subtype indication. This is syntactically a pain, but should |
| -- not propagate to the entity for the corresponding index subtype. |
| -- After checking that the subtype indication is legal, the range |
| -- of the subtype indication should be transfered to the entity. |
| -- The attributes for the bounds should remain the simple retrievals |
| -- that they are now. |
| |
| Lo_Bound := Type_Low_Bound (Ityp); |
| Hi_Bound := Type_High_Bound (Ityp); |
| |
| if not Is_Static_Subtype (Ityp) then |
| Static := False; |
| end if; |
| end Set_Bounds; |
| |
| ------------------------------- |
| -- Statically_Denotes_Entity -- |
| ------------------------------- |
| |
| function Statically_Denotes_Entity (N : Node_Id) return Boolean is |
| E : Entity_Id; |
| |
| begin |
| if not Is_Entity_Name (N) then |
| return False; |
| else |
| E := Entity (N); |
| end if; |
| |
| return |
| Nkind (Parent (E)) /= N_Object_Renaming_Declaration |
| or else Statically_Denotes_Entity (Renamed_Object (E)); |
| end Statically_Denotes_Entity; |
| |
| -- Start of processing for Eval_Attribute |
| |
| begin |
| -- Acquire first two expressions (at the moment, no attributes |
| -- take more than two expressions in any case). |
| |
| if Present (Expressions (N)) then |
| E1 := First (Expressions (N)); |
| E2 := Next (E1); |
| else |
| E1 := Empty; |
| E2 := Empty; |
| end if; |
| |
| -- Special processing for cases where the prefix is an object. For |
| -- this purpose, a string literal counts as an object (attributes |
| -- of string literals can only appear in generated code). |
| |
| if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then |
| |
| -- For Component_Size, the prefix is an array object, and we apply |
| -- the attribute to the type of the object. This is allowed for |
| -- both unconstrained and constrained arrays, since the bounds |
| -- have no influence on the value of this attribute. |
| |
| if Id = Attribute_Component_Size then |
| P_Entity := Etype (P); |
| |
| -- For First and Last, the prefix is an array object, and we apply |
| -- the attribute to the type of the array, but we need a constrained |
| -- type for this, so we use the actual subtype if available. |
| |
| elsif Id = Attribute_First |
| or else |
| Id = Attribute_Last |
| or else |
| Id = Attribute_Length |
| then |
| declare |
| AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P); |
| |
| begin |
| if Present (AS) and then Is_Constrained (AS) then |
| P_Entity := AS; |
| |
| -- If we have an unconstrained type, cannot fold |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| end; |
| |
| -- For Size, give size of object if available, otherwise we |
| -- cannot fold Size. |
| |
| elsif Id = Attribute_Size then |
| if Is_Entity_Name (P) |
| and then Known_Esize (Entity (P)) |
| then |
| Compile_Time_Known_Attribute (N, Esize (Entity (P))); |
| return; |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- For Alignment, give size of object if available, otherwise we |
| -- cannot fold Alignment. |
| |
| elsif Id = Attribute_Alignment then |
| if Is_Entity_Name (P) |
| and then Known_Alignment (Entity (P)) |
| then |
| Fold_Uint (N, Alignment (Entity (P)), False); |
| return; |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- No other attributes for objects are folded |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- Cases where P is not an object. Cannot do anything if P is |
| -- not the name of an entity. |
| |
| elsif not Is_Entity_Name (P) then |
| Check_Expressions; |
| return; |
| |
| -- Otherwise get prefix entity |
| |
| else |
| P_Entity := Entity (P); |
| end if; |
| |
| -- At this stage P_Entity is the entity to which the attribute |
| -- is to be applied. This is usually simply the entity of the |
| -- prefix, except in some cases of attributes for objects, where |
| -- as described above, we apply the attribute to the object type. |
| |
| -- First foldable possibility is a scalar or array type (RM 4.9(7)) |
| -- that is not generic (generic types are eliminated by RM 4.9(25)). |
| -- Note we allow non-static non-generic types at this stage as further |
| -- described below. |
| |
| if Is_Type (P_Entity) |
| and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity)) |
| and then (not Is_Generic_Type (P_Entity)) |
| then |
| P_Type := P_Entity; |
| |
| -- Second foldable possibility is an array object (RM 4.9(8)) |
| |
| elsif (Ekind (P_Entity) = E_Variable |
| or else |
| Ekind (P_Entity) = E_Constant) |
| and then Is_Array_Type (Etype (P_Entity)) |
| and then (not Is_Generic_Type (Etype (P_Entity))) |
| then |
| P_Type := Etype (P_Entity); |
| |
| -- If the entity is an array constant with an unconstrained nominal |
| -- subtype then get the type from the initial value. If the value has |
| -- been expanded into assignments, there is no expression and the |
| -- attribute reference remains dynamic. |
| -- We could do better here and retrieve the type ??? |
| |
| if Ekind (P_Entity) = E_Constant |
| and then not Is_Constrained (P_Type) |
| then |
| if No (Constant_Value (P_Entity)) then |
| return; |
| else |
| P_Type := Etype (Constant_Value (P_Entity)); |
| end if; |
| end if; |
| |
| -- Definite must be folded if the prefix is not a generic type, |
| -- that is to say if we are within an instantiation. Same processing |
| -- applies to the GNAT attributes Has_Discriminants, Type_Class, |
| -- and Unconstrained_Array. |
| |
| elsif (Id = Attribute_Definite |
| or else |
| Id = Attribute_Has_Access_Values |
| or else |
| Id = Attribute_Has_Discriminants |
| or else |
| Id = Attribute_Type_Class |
| or else |
| Id = Attribute_Unconstrained_Array) |
| and then not Is_Generic_Type (P_Entity) |
| then |
| P_Type := P_Entity; |
| |
| -- We can fold 'Size applied to a type if the size is known |
| -- (as happens for a size from an attribute definition clause). |
| -- At this stage, this can happen only for types (e.g. record |
| -- types) for which the size is always non-static. We exclude |
| -- generic types from consideration (since they have bogus |
| -- sizes set within templates). |
| |
| elsif Id = Attribute_Size |
| and then Is_Type (P_Entity) |
| and then (not Is_Generic_Type (P_Entity)) |
| and then Known_Static_RM_Size (P_Entity) |
| then |
| Compile_Time_Known_Attribute (N, RM_Size (P_Entity)); |
| return; |
| |
| -- We can fold 'Alignment applied to a type if the alignment is known |
| -- (as happens for an alignment from an attribute definition clause). |
| -- At this stage, this can happen only for types (e.g. record |
| -- types) for which the size is always non-static. We exclude |
| -- generic types from consideration (since they have bogus |
| -- sizes set within templates). |
| |
| elsif Id = Attribute_Alignment |
| and then Is_Type (P_Entity) |
| and then (not Is_Generic_Type (P_Entity)) |
| and then Known_Alignment (P_Entity) |
| then |
| Compile_Time_Known_Attribute (N, Alignment (P_Entity)); |
| return; |
| |
| -- If this is an access attribute that is known to fail accessibility |
| -- check, rewrite accordingly. |
| |
| elsif Attribute_Name (N) = Name_Access |
| and then Raises_Constraint_Error (N) |
| then |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, C_Type); |
| return; |
| |
| -- No other cases are foldable (they certainly aren't static, and at |
| -- the moment we don't try to fold any cases other than these three). |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- If either attribute or the prefix is Any_Type, then propagate |
| -- Any_Type to the result and don't do anything else at all. |
| |
| if P_Type = Any_Type |
| or else (Present (E1) and then Etype (E1) = Any_Type) |
| or else (Present (E2) and then Etype (E2) = Any_Type) |
| then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Scalar subtype case. We have not yet enforced the static requirement |
| -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases |
| -- of non-static attribute references (e.g. S'Digits for a non-static |
| -- floating-point type, which we can compute at compile time). |
| |
| -- Note: this folding of non-static attributes is not simply a case of |
| -- optimization. For many of the attributes affected, Gigi cannot handle |
| -- the attribute and depends on the front end having folded them away. |
| |
| -- Note: although we don't require staticness at this stage, we do set |
| -- the Static variable to record the staticness, for easy reference by |
| -- those attributes where it matters (e.g. Succ and Pred), and also to |
| -- be used to ensure that non-static folded things are not marked as |
| -- being static (a check that is done right at the end). |
| |
| P_Root_Type := Root_Type (P_Type); |
| P_Base_Type := Base_Type (P_Type); |
| |
| -- If the root type or base type is generic, then we cannot fold. This |
| -- test is needed because subtypes of generic types are not always |
| -- marked as being generic themselves (which seems odd???) |
| |
| if Is_Generic_Type (P_Root_Type) |
| or else Is_Generic_Type (P_Base_Type) |
| then |
| return; |
| end if; |
| |
| if Is_Scalar_Type (P_Type) then |
| Static := Is_OK_Static_Subtype (P_Type); |
| |
| -- Array case. We enforce the constrained requirement of (RM 4.9(7-8)) |
| -- since we can't do anything with unconstrained arrays. In addition, |
| -- only the First, Last and Length attributes are possibly static. |
| |
| -- Definite, Has_Access_Values, Has_Discriminants, Type_Class, and |
| -- Unconstrained_Array are again exceptions, because they apply as |
| -- well to unconstrained types. |
| |
| -- In addition Component_Size is an exception since it is possibly |
| -- foldable, even though it is never static, and it does apply to |
| -- unconstrained arrays. Furthermore, it is essential to fold this |
| -- in the packed case, since otherwise the value will be incorrect. |
| |
| elsif Id = Attribute_Definite |
| or else |
| Id = Attribute_Has_Access_Values |
| or else |
| Id = Attribute_Has_Discriminants |
| or else |
| Id = Attribute_Type_Class |
| or else |
| Id = Attribute_Unconstrained_Array |
| or else |
| Id = Attribute_Component_Size |
| then |
| Static := False; |
| |
| else |
| if not Is_Constrained (P_Type) |
| or else (Id /= Attribute_First and then |
| Id /= Attribute_Last and then |
| Id /= Attribute_Length) |
| then |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- The rules in (RM 4.9(7,8)) require a static array, but as in the |
| -- scalar case, we hold off on enforcing staticness, since there are |
| -- cases which we can fold at compile time even though they are not |
| -- static (e.g. 'Length applied to a static index, even though other |
| -- non-static indexes make the array type non-static). This is only |
| -- an optimization, but it falls out essentially free, so why not. |
| -- Again we compute the variable Static for easy reference later |
| -- (note that no array attributes are static in Ada 83). |
| |
| Static := Ada_Version >= Ada_95 |
| and then Statically_Denotes_Entity (P); |
| |
| declare |
| N : Node_Id; |
| |
| begin |
| N := First_Index (P_Type); |
| while Present (N) loop |
| Static := Static and then Is_Static_Subtype (Etype (N)); |
| |
| -- If however the index type is generic, attributes cannot |
| -- be folded. |
| |
| if Is_Generic_Type (Etype (N)) |
| and then Id /= Attribute_Component_Size |
| then |
| return; |
| end if; |
| |
| Next_Index (N); |
| end loop; |
| end; |
| end if; |
| |
| -- Check any expressions that are present. Note that these expressions, |
| -- depending on the particular attribute type, are either part of the |
| -- attribute designator, or they are arguments in a case where the |
| -- attribute reference returns a function. In the latter case, the |
| -- rule in (RM 4.9(22)) applies and in particular requires the type |
| -- of the expressions to be scalar in order for the attribute to be |
| -- considered to be static. |
| |
| declare |
| E : Node_Id; |
| |
| begin |
| E := E1; |
| while Present (E) loop |
| |
| -- If expression is not static, then the attribute reference |
| -- result certainly cannot be static. |
| |
| if not Is_Static_Expression (E) then |
| Static := False; |
| end if; |
| |
| -- If the result is not known at compile time, or is not of |
| -- a scalar type, then the result is definitely not static, |
| -- so we can quit now. |
| |
| if not Compile_Time_Known_Value (E) |
| or else not Is_Scalar_Type (Etype (E)) |
| then |
| -- An odd special case, if this is a Pos attribute, this |
| -- is where we need to apply a range check since it does |
| -- not get done anywhere else. |
| |
| if Id = Attribute_Pos then |
| if Is_Integer_Type (Etype (E)) then |
| Apply_Range_Check (E, Etype (N)); |
| end if; |
| end if; |
| |
| Check_Expressions; |
| return; |
| |
| -- If the expression raises a constraint error, then so does |
| -- the attribute reference. We keep going in this case because |
| -- we are still interested in whether the attribute reference |
| -- is static even if it is not static. |
| |
| elsif Raises_Constraint_Error (E) then |
| Set_Raises_Constraint_Error (N); |
| end if; |
| |
| Next (E); |
| end loop; |
| |
| if Raises_Constraint_Error (Prefix (N)) then |
| return; |
| end if; |
| end; |
| |
| -- Deal with the case of a static attribute reference that raises |
| -- constraint error. The Raises_Constraint_Error flag will already |
| -- have been set, and the Static flag shows whether the attribute |
| -- reference is static. In any case we certainly can't fold such an |
| -- attribute reference. |
| |
| -- Note that the rewriting of the attribute node with the constraint |
| -- error node is essential in this case, because otherwise Gigi might |
| -- blow up on one of the attributes it never expects to see. |
| |
| -- The constraint_error node must have the type imposed by the context, |
| -- to avoid spurious errors in the enclosing expression. |
| |
| if Raises_Constraint_Error (N) then |
| CE_Node := |
| Make_Raise_Constraint_Error (Sloc (N), |
| Reason => CE_Range_Check_Failed); |
| Set_Etype (CE_Node, Etype (N)); |
| Set_Raises_Constraint_Error (CE_Node); |
| Check_Expressions; |
| Rewrite (N, Relocate_Node (CE_Node)); |
| Set_Is_Static_Expression (N, Static); |
| return; |
| end if; |
| |
| -- At this point we have a potentially foldable attribute reference. |
| -- If Static is set, then the attribute reference definitely obeys |
| -- the requirements in (RM 4.9(7,8,22)), and it definitely can be |
| -- folded. If Static is not set, then the attribute may or may not |
| -- be foldable, and the individual attribute processing routines |
| -- test Static as required in cases where it makes a difference. |
| |
| -- In the case where Static is not set, we do know that all the |
| -- expressions present are at least known at compile time (we |
| -- assumed above that if this was not the case, then there was |
| -- no hope of static evaluation). However, we did not require |
| -- that the bounds of the prefix type be compile time known, |
| -- let alone static). That's because there are many attributes |
| -- that can be computed at compile time on non-static subtypes, |
| -- even though such references are not static expressions. |
| |
| case Id is |
| |
| -------------- |
| -- Adjacent -- |
| -------------- |
| |
| when Attribute_Adjacent => |
| Fold_Ureal (N, |
| Eval_Fat.Adjacent |
| (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static); |
| |
| --------- |
| -- Aft -- |
| --------- |
| |
| when Attribute_Aft => |
| Fold_Uint (N, UI_From_Int (Aft_Value), True); |
| |
| --------------- |
| -- Alignment -- |
| --------------- |
| |
| when Attribute_Alignment => Alignment_Block : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| -- Fold if alignment is set and not otherwise |
| |
| if Known_Alignment (P_TypeA) then |
| Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA)); |
| end if; |
| end Alignment_Block; |
| |
| --------------- |
| -- AST_Entry -- |
| --------------- |
| |
| -- Can only be folded in No_Ast_Handler case |
| |
| when Attribute_AST_Entry => |
| if not Is_AST_Entry (P_Entity) then |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc)); |
| else |
| null; |
| end if; |
| |
| --------- |
| -- Bit -- |
| --------- |
| |
| -- Bit can never be folded |
| |
| when Attribute_Bit => |
| null; |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| -- Body_version can never be static |
| |
| when Attribute_Body_Version => |
| null; |
| |
| ------------- |
| -- Ceiling -- |
| ------------- |
| |
| when Attribute_Ceiling => |
| Fold_Ureal (N, |
| Eval_Fat.Ceiling (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| -------------------- |
| -- Component_Size -- |
| -------------------- |
| |
| when Attribute_Component_Size => |
| if Known_Static_Component_Size (P_Type) then |
| Fold_Uint (N, Component_Size (P_Type), False); |
| end if; |
| |
| ------------- |
| -- Compose -- |
| ------------- |
| |
| when Attribute_Compose => |
| Fold_Ureal (N, |
| Eval_Fat.Compose |
| (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), |
| Static); |
| |
| ----------------- |
| -- Constrained -- |
| ----------------- |
| |
| -- Constrained is never folded for now, there may be cases that |
| -- could be handled at compile time. to be looked at later. |
| |
| when Attribute_Constrained => |
| null; |
| |
| --------------- |
| -- Copy_Sign -- |
| --------------- |
| |
| when Attribute_Copy_Sign => |
| Fold_Ureal (N, |
| Eval_Fat.Copy_Sign |
| (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static); |
| |
| ----------- |
| -- Delta -- |
| ----------- |
| |
| when Attribute_Delta => |
| Fold_Ureal (N, Delta_Value (P_Type), True); |
| |
| -------------- |
| -- Definite -- |
| -------------- |
| |
| when Attribute_Definite => |
| Rewrite (N, New_Occurrence_Of ( |
| Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| ------------ |
| -- Denorm -- |
| ------------ |
| |
| when Attribute_Denorm => |
| Fold_Uint |
| (N, UI_From_Int (Boolean'Pos (Denorm_On_Target)), True); |
| |
| ------------ |
| -- Digits -- |
| ------------ |
| |
| when Attribute_Digits => |
| Fold_Uint (N, Digits_Value (P_Type), True); |
| |
| ---------- |
| -- Emax -- |
| ---------- |
| |
| when Attribute_Emax => |
| |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Emax = 4 * T'Mantissa |
| |
| Fold_Uint (N, 4 * Mantissa, True); |
| |
| -------------- |
| -- Enum_Rep -- |
| -------------- |
| |
| when Attribute_Enum_Rep => |
| |
| -- For an enumeration type with a non-standard representation use |
| -- the Enumeration_Rep field of the proper constant. Note that this |
| -- will not work for types Character/Wide_[Wide-]Character, since no |
| -- real entities are created for the enumeration literals, but that |
| -- does not matter since these two types do not have non-standard |
| -- representations anyway. |
| |
| if Is_Enumeration_Type (P_Type) |
| and then Has_Non_Standard_Rep (P_Type) |
| then |
| Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static); |
| |
| -- For enumeration types with standard representations and all |
| -- other cases (i.e. all integer and modular types), Enum_Rep |
| -- is equivalent to Pos. |
| |
| else |
| Fold_Uint (N, Expr_Value (E1), Static); |
| end if; |
| |
| ------------- |
| -- Epsilon -- |
| ------------- |
| |
| when Attribute_Epsilon => |
| |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Epsilon = 2.0**(1 - T'Mantissa) |
| |
| Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True); |
| |
| -------------- |
| -- Exponent -- |
| -------------- |
| |
| when Attribute_Exponent => |
| Fold_Uint (N, |
| Eval_Fat.Exponent (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| ----------- |
| -- First -- |
| ----------- |
| |
| when Attribute_First => First_Attr : |
| begin |
| Set_Bounds; |
| |
| if Compile_Time_Known_Value (Lo_Bound) then |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static); |
| else |
| Fold_Uint (N, Expr_Value (Lo_Bound), Static); |
| end if; |
| end if; |
| end First_Attr; |
| |
| ----------------- |
| -- Fixed_Value -- |
| ----------------- |
| |
| when Attribute_Fixed_Value => |
| null; |
| |
| ----------- |
| -- Floor -- |
| ----------- |
| |
| when Attribute_Floor => |
| Fold_Ureal (N, |
| Eval_Fat.Floor (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| ---------- |
| -- Fore -- |
| ---------- |
| |
| when Attribute_Fore => |
| if Compile_Time_Known_Bounds (P_Type) then |
| Fold_Uint (N, UI_From_Int (Fore_Value), Static); |
| end if; |
| |
| -------------- |
| -- Fraction -- |
| -------------- |
| |
| when Attribute_Fraction => |
| Fold_Ureal (N, |
| Eval_Fat.Fraction (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| ----------------------- |
| -- Has_Access_Values -- |
| ----------------------- |
| |
| when Attribute_Has_Access_Values => |
| Rewrite (N, New_Occurrence_Of |
| (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| ----------------------- |
| -- Has_Discriminants -- |
| ----------------------- |
| |
| when Attribute_Has_Discriminants => |
| Rewrite (N, New_Occurrence_Of ( |
| Boolean_Literals (Has_Discriminants (P_Entity)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| -------------- |
| -- Identity -- |
| -------------- |
| |
| when Attribute_Identity => |
| null; |
| |
| ----------- |
| -- Image -- |
| ----------- |
| |
| -- Image is a scalar attribute, but is never static, because it is |
| -- not a static function (having a non-scalar argument (RM 4.9(22)) |
| |
| when Attribute_Image => |
| null; |
| |
| --------- |
| -- Img -- |
| --------- |
| |
| -- Img is a scalar attribute, but is never static, because it is |
| -- not a static function (having a non-scalar argument (RM 4.9(22)) |
| |
| when Attribute_Img => |
| null; |
| |
| ------------------- |
| -- Integer_Value -- |
| ------------------- |
| |
| when Attribute_Integer_Value => |
| null; |
| |
| ----------- |
| -- Large -- |
| ----------- |
| |
| when Attribute_Large => |
| |
| -- For fixed-point, we use the identity: |
| |
| -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Rewrite (N, |
| Make_Op_Multiply (Loc, |
| Left_Opnd => |
| Make_Op_Subtract (Loc, |
| Left_Opnd => |
| Make_Op_Expon (Loc, |
| Left_Opnd => |
| Make_Real_Literal (Loc, Ureal_2), |
| Right_Opnd => |
| Make_Attribute_Reference (Loc, |
| Prefix => P, |
| Attribute_Name => Name_Mantissa)), |
| Right_Opnd => Make_Real_Literal (Loc, Ureal_1)), |
| |
| Right_Opnd => |
| Make_Real_Literal (Loc, Small_Value (Entity (P))))); |
| |
| Analyze_And_Resolve (N, C_Type); |
| |
| -- Floating-point (Ada 83 compatibility) |
| |
| else |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa)) |
| |
| -- where |
| |
| -- T'Emax = 4 * T'Mantissa |
| |
| Fold_Ureal (N, |
| Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)), |
| True); |
| end if; |
| |
| ---------- |
| -- Last -- |
| ---------- |
| |
| when Attribute_Last => Last : |
| begin |
| Set_Bounds; |
| |
| if Compile_Time_Known_Value (Hi_Bound) then |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static); |
| else |
| Fold_Uint (N, Expr_Value (Hi_Bound), Static); |
| end if; |
| end if; |
| end Last; |
| |
| ------------------ |
| -- Leading_Part -- |
| ------------------ |
| |
| when Attribute_Leading_Part => |
| Fold_Ureal (N, |
| Eval_Fat.Leading_Part |
| (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static); |
| |
| ------------ |
| -- Length -- |
| ------------ |
| |
| when Attribute_Length => Length : declare |
| Ind : Node_Id; |
| |
| begin |
| -- In the case of a generic index type, the bounds may |
| -- appear static but the computation is not meaningful, |
| -- and may generate a spurious warning. |
| |
| Ind := First_Index (P_Type); |
| |
| while Present (Ind) loop |
| if Is_Generic_Type (Etype (Ind)) then |
| return; |
| end if; |
| |
| Next_Index (Ind); |
| end loop; |
| |
| Set_Bounds; |
| |
| if Compile_Time_Known_Value (Lo_Bound) |
| and then Compile_Time_Known_Value (Hi_Bound) |
| then |
| Fold_Uint (N, |
| UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))), |
| True); |
| end if; |
| end Length; |
| |
| ------------- |
| -- Machine -- |
| ------------- |
| |
| when Attribute_Machine => |
| Fold_Ureal (N, |
| Eval_Fat.Machine |
| (P_Root_Type, Expr_Value_R (E1), Eval_Fat.Round, N), |
| Static); |
| |
| ------------------ |
| -- Machine_Emax -- |
| ------------------ |
| |
| when Attribute_Machine_Emax => |
| Float_Attribute_Universal_Integer ( |
| IEEES_Machine_Emax, |
| IEEEL_Machine_Emax, |
| IEEEX_Machine_Emax, |
| VAXFF_Machine_Emax, |
| VAXDF_Machine_Emax, |
| VAXGF_Machine_Emax, |
| AAMPS_Machine_Emax, |
| AAMPL_Machine_Emax); |
| |
| ------------------ |
| -- Machine_Emin -- |
| ------------------ |
| |
| when Attribute_Machine_Emin => |
| Float_Attribute_Universal_Integer ( |
| IEEES_Machine_Emin, |
| IEEEL_Machine_Emin, |
| IEEEX_Machine_Emin, |
| VAXFF_Machine_Emin, |
| VAXDF_Machine_Emin, |
| VAXGF_Machine_Emin, |
| AAMPS_Machine_Emin, |
| AAMPL_Machine_Emin); |
| |
| ---------------------- |
| -- Machine_Mantissa -- |
| ---------------------- |
| |
| when Attribute_Machine_Mantissa => |
| Float_Attribute_Universal_Integer ( |
| IEEES_Machine_Mantissa, |
| IEEEL_Machine_Mantissa, |
| IEEEX_Machine_Mantissa, |
| VAXFF_Machine_Mantissa, |
| VAXDF_Machine_Mantissa, |
| VAXGF_Machine_Mantissa, |
| AAMPS_Machine_Mantissa, |
| AAMPL_Machine_Mantissa); |
| |
| ----------------------- |
| -- Machine_Overflows -- |
| ----------------------- |
| |
| when Attribute_Machine_Overflows => |
| |
| -- Always true for fixed-point |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Uint (N, True_Value, True); |
| |
| -- Floating point case |
| |
| else |
| Fold_Uint (N, |
| UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)), |
| True); |
| end if; |
| |
| ------------------- |
| -- Machine_Radix -- |
| ------------------- |
| |
| when Attribute_Machine_Radix => |
| if Is_Fixed_Point_Type (P_Type) then |
| if Is_Decimal_Fixed_Point_Type (P_Type) |
| and then Machine_Radix_10 (P_Type) |
| then |
| Fold_Uint (N, Uint_10, True); |
| else |
| Fold_Uint (N, Uint_2, True); |
| end if; |
| |
| -- All floating-point type always have radix 2 |
| |
| else |
| Fold_Uint (N, Uint_2, True); |
| end if; |
| |
| ---------------------- |
| -- Machine_Rounding -- |
| ---------------------- |
| |
| -- Note: for the folding case, it is fine to treat Machine_Rounding |
| -- exactly the same way as Rounding, since this is one of the allowed |
| -- behaviors, and performance is not an issue here. It might be a bit |
| -- better to give the same result as it would give at run-time, even |
| -- though the non-determinism is certainly permitted. |
| |
| when Attribute_Machine_Rounding => |
| Fold_Ureal (N, |
| Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| -------------------- |
| -- Machine_Rounds -- |
| -------------------- |
| |
| when Attribute_Machine_Rounds => |
| |
| -- Always False for fixed-point |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Uint (N, False_Value, True); |
| |
| -- Else yield proper floating-point result |
| |
| else |
| Fold_Uint |
| (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True); |
| end if; |
| |
| ------------------ |
| -- Machine_Size -- |
| ------------------ |
| |
| -- Note: Machine_Size is identical to Object_Size |
| |
| when Attribute_Machine_Size => Machine_Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if Known_Esize (P_TypeA) then |
| Fold_Uint (N, Esize (P_TypeA), True); |
| end if; |
| end Machine_Size; |
| |
| -------------- |
| -- Mantissa -- |
| -------------- |
| |
| when Attribute_Mantissa => |
| |
| -- Fixed-point mantissa |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| |
| -- Compile time foldable case |
| |
| if Compile_Time_Known_Value (Type_Low_Bound (P_Type)) |
| and then |
| Compile_Time_Known_Value (Type_High_Bound (P_Type)) |
| then |
| -- The calculation of the obsolete Ada 83 attribute Mantissa |
| -- is annoying, because of AI00143, quoted here: |
| |
| -- !question 84-01-10 |
| |
| -- Consider the model numbers for F: |
| |
| -- type F is delta 1.0 range -7.0 .. 8.0; |
| |
| -- The wording requires that F'MANTISSA be the SMALLEST |
| -- integer number for which each bound of the specified |
| -- range is either a model number or lies at most small |
| -- distant from a model number. This means F'MANTISSA |
| -- is required to be 3 since the range -7.0 .. 7.0 fits |
| -- in 3 signed bits, and 8 is "at most" 1.0 from a model |
| -- number, namely, 7. Is this analysis correct? Note that |
| -- this implies the upper bound of the range is not |
| -- represented as a model number. |
| |
| -- !response 84-03-17 |
| |
| -- The analysis is correct. The upper and lower bounds for |
| -- a fixed point type can lie outside the range of model |
| -- numbers. |
| |
| declare |
| Siz : Uint; |
| LBound : Ureal; |
| UBound : Ureal; |
| Bound : Ureal; |
| Max_Man : Uint; |
| |
| begin |
| LBound := Expr_Value_R (Type_Low_Bound (P_Type)); |
| UBound := Expr_Value_R (Type_High_Bound (P_Type)); |
| Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound)); |
| Max_Man := UR_Trunc (Bound / Small_Value (P_Type)); |
| |
| -- If the Bound is exactly a model number, i.e. a multiple |
| -- of Small, then we back it off by one to get the integer |
| -- value that must be representable. |
| |
| if Small_Value (P_Type) * Max_Man = Bound then |
| Max_Man := Max_Man - 1; |
| end if; |
| |
| -- Now find corresponding size = Mantissa value |
| |
| Siz := Uint_0; |
| while 2 ** Siz < Max_Man loop |
| Siz := Siz + 1; |
| end loop; |
| |
| Fold_Uint (N, Siz, True); |
| end; |
| |
| else |
| -- The case of dynamic bounds cannot be evaluated at compile |
| -- time. Instead we use a runtime routine (see Exp_Attr). |
| |
| null; |
| end if; |
| |
| -- Floating-point Mantissa |
| |
| else |
| Fold_Uint (N, Mantissa, True); |
| end if; |
| |
| --------- |
| -- Max -- |
| --------- |
| |
| when Attribute_Max => Max : |
| begin |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal |
| (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static); |
| else |
| Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static); |
| end if; |
| end Max; |
| |
| ---------------------------------- |
| -- Max_Size_In_Storage_Elements -- |
| ---------------------------------- |
| |
| -- Max_Size_In_Storage_Elements is simply the Size rounded up to a |
| -- Storage_Unit boundary. We can fold any cases for which the size |
| -- is known by the front end. |
| |
| when Attribute_Max_Size_In_Storage_Elements => |
| if Known_Esize (P_Type) then |
| Fold_Uint (N, |
| (Esize (P_Type) + System_Storage_Unit - 1) / |
| System_Storage_Unit, |
| Static); |
| end if; |
| |
| -------------------- |
| -- Mechanism_Code -- |
| -------------------- |
| |
| when Attribute_Mechanism_Code => |
| declare |
| Val : Int; |
| Formal : Entity_Id; |
| Mech : Mechanism_Type; |
| |
| begin |
| if No (E1) then |
| Mech := Mechanism (P_Entity); |
| |
| else |
| Val := UI_To_Int (Expr_Value (E1)); |
| |
| Formal := First_Formal (P_Entity); |
| for J in 1 .. Val - 1 loop |
| Next_Formal (Formal); |
| end loop; |
| Mech := Mechanism (Formal); |
| end if; |
| |
| if Mech < 0 then |
| Fold_Uint (N, UI_From_Int (Int (-Mech)), True); |
| end if; |
| end; |
| |
| --------- |
| -- Min -- |
| --------- |
| |
| when Attribute_Min => Min : |
| begin |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal |
| (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static); |
| else |
| Fold_Uint |
| (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static); |
| end if; |
| end Min; |
| |
| --------- |
| -- Mod -- |
| --------- |
| |
| when Attribute_Mod => |
| Fold_Uint |
| (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static); |
| |
| ----------- |
| -- Model -- |
| ----------- |
| |
| when Attribute_Model => |
| Fold_Ureal (N, |
| Eval_Fat.Model (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| ---------------- |
| -- Model_Emin -- |
| ---------------- |
| |
| when Attribute_Model_Emin => |
| Float_Attribute_Universal_Integer ( |
| IEEES_Model_Emin, |
| IEEEL_Model_Emin, |
| IEEEX_Model_Emin, |
| VAXFF_Model_Emin, |
| VAXDF_Model_Emin, |
| VAXGF_Model_Emin, |
| AAMPS_Model_Emin, |
| AAMPL_Model_Emin); |
| |
| ------------------- |
| -- Model_Epsilon -- |
| ------------------- |
| |
| when Attribute_Model_Epsilon => |
| Float_Attribute_Universal_Real ( |
| IEEES_Model_Epsilon'Universal_Literal_String, |
| IEEEL_Model_Epsilon'Universal_Literal_String, |
| IEEEX_Model_Epsilon'Universal_Literal_String, |
| VAXFF_Model_Epsilon'Universal_Literal_String, |
| VAXDF_Model_Epsilon'Universal_Literal_String, |
| VAXGF_Model_Epsilon'Universal_Literal_String, |
| AAMPS_Model_Epsilon'Universal_Literal_String, |
| AAMPL_Model_Epsilon'Universal_Literal_String); |
| |
| -------------------- |
| -- Model_Mantissa -- |
| -------------------- |
| |
| when Attribute_Model_Mantissa => |
| Float_Attribute_Universal_Integer ( |
| IEEES_Model_Mantissa, |
| IEEEL_Model_Mantissa, |
| IEEEX_Model_Mantissa, |
| VAXFF_Model_Mantissa, |
| VAXDF_Model_Mantissa, |
| VAXGF_Model_Mantissa, |
| AAMPS_Model_Mantissa, |
| AAMPL_Model_Mantissa); |
| |
| ----------------- |
| -- Model_Small -- |
| ----------------- |
| |
| when Attribute_Model_Small => |
| Float_Attribute_Universal_Real ( |
| IEEES_Model_Small'Universal_Literal_String, |
| IEEEL_Model_Small'Universal_Literal_String, |
| IEEEX_Model_Small'Universal_Literal_String, |
| VAXFF_Model_Small'Universal_Literal_String, |
| VAXDF_Model_Small'Universal_Literal_String, |
| VAXGF_Model_Small'Universal_Literal_String, |
| AAMPS_Model_Small'Universal_Literal_String, |
| AAMPL_Model_Small'Universal_Literal_String); |
| |
| ------------- |
| -- Modulus -- |
| ------------- |
| |
| when Attribute_Modulus => |
| Fold_Uint (N, Modulus (P_Type), True); |
| |
| -------------------- |
| -- Null_Parameter -- |
| -------------------- |
| |
| -- Cannot fold, we know the value sort of, but the whole point is |
| -- that there is no way to talk about this imaginary value except |
| -- by using the attribute, so we leave it the way it is. |
| |
| when Attribute_Null_Parameter => |
| null; |
| |
| ----------------- |
| -- Object_Size -- |
| ----------------- |
| |
| -- The Object_Size attribute for a type returns the Esize of the |
| -- type and can be folded if this value is known. |
| |
| when Attribute_Object_Size => Object_Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if Known_Esize (P_TypeA) then |
| Fold_Uint (N, Esize (P_TypeA), True); |
| end if; |
| end Object_Size; |
| |
| ------------------------- |
| -- Passed_By_Reference -- |
| ------------------------- |
| |
| -- Scalar types are never passed by reference |
| |
| when Attribute_Passed_By_Reference => |
| Fold_Uint (N, False_Value, True); |
| |
| --------- |
| -- Pos -- |
| --------- |
| |
| when Attribute_Pos => |
| Fold_Uint (N, Expr_Value (E1), True); |
| |
| ---------- |
| -- Pred -- |
| ---------- |
| |
| when Attribute_Pred => Pred : |
| begin |
| -- Floating-point case |
| |
| if Is_Floating_Point_Type (P_Type) then |
| Fold_Ureal (N, |
| Eval_Fat.Pred (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| -- Fixed-point case |
| |
| elsif Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal (N, |
| Expr_Value_R (E1) - Small_Value (P_Type), True); |
| |
| -- Modular integer case (wraps) |
| |
| elsif Is_Modular_Integer_Type (P_Type) then |
| Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static); |
| |
| -- Other scalar cases |
| |
| else |
| pragma Assert (Is_Scalar_Type (P_Type)); |
| |
| if Is_Enumeration_Type (P_Type) |
| and then Expr_Value (E1) = |
| Expr_Value (Type_Low_Bound (P_Base_Type)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "Pred of `&''First`", |
| CE_Overflow_Check_Failed, |
| Ent => P_Base_Type, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| end if; |
| |
| Fold_Uint (N, Expr_Value (E1) - 1, Static); |
| end if; |
| end Pred; |
| |
| ----------- |
| -- Range -- |
| ----------- |
| |
| -- No processing required, because by this stage, Range has been |
| -- replaced by First .. Last, so this branch can never be taken. |
| |
| when Attribute_Range => |
| raise Program_Error; |
| |
| ------------------ |
| -- Range_Length -- |
| ------------------ |
| |
| when Attribute_Range_Length => |
| Set_Bounds; |
| |
| if Compile_Time_Known_Value (Hi_Bound) |
| and then Compile_Time_Known_Value (Lo_Bound) |
| then |
| Fold_Uint (N, |
| UI_Max |
| (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1), |
| Static); |
| end if; |
| |
| --------------- |
| -- Remainder -- |
| --------------- |
| |
| when Attribute_Remainder => Remainder : declare |
| X : constant Ureal := Expr_Value_R (E1); |
| Y : constant Ureal := Expr_Value_R (E2); |
| |
| begin |
| if UR_Is_Zero (Y) then |
| Apply_Compile_Time_Constraint_Error |
| (N, "division by zero in Remainder", |
| CE_Overflow_Check_Failed, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| end if; |
| |
| Fold_Ureal (N, Eval_Fat.Remainder (P_Root_Type, X, Y), Static); |
| end Remainder; |
| |
| ----------- |
| -- Round -- |
| ----------- |
| |
| when Attribute_Round => Round : |
| declare |
| Sr : Ureal; |
| Si : Uint; |
| |
| begin |
| -- First we get the (exact result) in units of small |
| |
| Sr := Expr_Value_R (E1) / Small_Value (C_Type); |
| |
| -- Now round that exactly to an integer |
| |
| Si := UR_To_Uint (Sr); |
| |
| -- Finally the result is obtained by converting back to real |
| |
| Fold_Ureal (N, Si * Small_Value (C_Type), Static); |
| end Round; |
| |
| -------------- |
| -- Rounding -- |
| -------------- |
| |
| when Attribute_Rounding => |
| Fold_Ureal (N, |
| Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| --------------- |
| -- Safe_Emax -- |
| --------------- |
| |
| when Attribute_Safe_Emax => |
| Float_Attribute_Universal_Integer ( |
| IEEES_Safe_Emax, |
| IEEEL_Safe_Emax, |
| IEEEX_Safe_Emax, |
| VAXFF_Safe_Emax, |
| VAXDF_Safe_Emax, |
| VAXGF_Safe_Emax, |
| AAMPS_Safe_Emax, |
| AAMPL_Safe_Emax); |
| |
| ---------------- |
| -- Safe_First -- |
| ---------------- |
| |
| when Attribute_Safe_First => |
| Float_Attribute_Universal_Real ( |
| IEEES_Safe_First'Universal_Literal_String, |
| IEEEL_Safe_First'Universal_Literal_String, |
| IEEEX_Safe_First'Universal_Literal_String, |
| VAXFF_Safe_First'Universal_Literal_String, |
| VAXDF_Safe_First'Universal_Literal_String, |
| VAXGF_Safe_First'Universal_Literal_String, |
| AAMPS_Safe_First'Universal_Literal_String, |
| AAMPL_Safe_First'Universal_Literal_String); |
| |
| ---------------- |
| -- Safe_Large -- |
| ---------------- |
| |
| when Attribute_Safe_Large => |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal |
| (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static); |
| else |
| Float_Attribute_Universal_Real ( |
| IEEES_Safe_Large'Universal_Literal_String, |
| IEEEL_Safe_Large'Universal_Literal_String, |
| IEEEX_Safe_Large'Universal_Literal_String, |
| VAXFF_Safe_Large'Universal_Literal_String, |
| VAXDF_Safe_Large'Universal_Literal_String, |
| VAXGF_Safe_Large'Universal_Literal_String, |
| AAMPS_Safe_Large'Universal_Literal_String, |
| AAMPL_Safe_Large'Universal_Literal_String); |
| end if; |
| |
| --------------- |
| -- Safe_Last -- |
| --------------- |
| |
| when Attribute_Safe_Last => |
| Float_Attribute_Universal_Real ( |
| IEEES_Safe_Last'Universal_Literal_String, |
| IEEEL_Safe_Last'Universal_Literal_String, |
| IEEEX_Safe_Last'Universal_Literal_String, |
| VAXFF_Safe_Last'Universal_Literal_String, |
| VAXDF_Safe_Last'Universal_Literal_String, |
| VAXGF_Safe_Last'Universal_Literal_String, |
| AAMPS_Safe_Last'Universal_Literal_String, |
| AAMPL_Safe_Last'Universal_Literal_String); |
| |
| ---------------- |
| -- Safe_Small -- |
| ---------------- |
| |
| when Attribute_Safe_Small => |
| |
| -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant |
| -- for fixed-point, since is the same as Small, but we implement |
| -- it for backwards compatibility. |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal (N, Small_Value (P_Type), Static); |
| |
| -- Ada 83 Safe_Small for floating-point cases |
| |
| else |
| Float_Attribute_Universal_Real ( |
| IEEES_Safe_Small'Universal_Literal_String, |
| IEEEL_Safe_Small'Universal_Literal_String, |
| IEEEX_Safe_Small'Universal_Literal_String, |
| VAXFF_Safe_Small'Universal_Literal_String, |
| VAXDF_Safe_Small'Universal_Literal_String, |
| VAXGF_Safe_Small'Universal_Literal_String, |
| AAMPS_Safe_Small'Universal_Literal_String, |
| AAMPL_Safe_Small'Universal_Literal_String); |
| end if; |
| |
| ----------- |
| -- Scale -- |
| ----------- |
| |
| when Attribute_Scale => |
| Fold_Uint (N, Scale_Value (P_Type), True); |
| |
| ------------- |
| -- Scaling -- |
| ------------- |
| |
| when Attribute_Scaling => |
| Fold_Ureal (N, |
| Eval_Fat.Scaling |
| (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static); |
| |
| ------------------ |
| -- Signed_Zeros -- |
| ------------------ |
| |
| when Attribute_Signed_Zeros => |
| Fold_Uint |
| (N, UI_From_Int (Boolean'Pos (Signed_Zeros_On_Target)), Static); |
| |
| ---------- |
| -- Size -- |
| ---------- |
| |
| -- Size attribute returns the RM size. All scalar types can be folded, |
| -- as well as any types for which the size is known by the front end, |
| -- including any type for which a size attribute is specified. |
| |
| when Attribute_Size | Attribute_VADS_Size => Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if RM_Size (P_TypeA) /= Uint_0 then |
| |
| -- VADS_Size case |
| |
| if Id = Attribute_VADS_Size or else Use_VADS_Size then |
| declare |
| S : constant Node_Id := Size_Clause (P_TypeA); |
| |
| begin |
| -- If a size clause applies, then use the size from it. |
| -- This is one of the rare cases where we can use the |
| -- Size_Clause field for a subtype when Has_Size_Clause |
| -- is False. Consider: |
| |
| -- type x is range 1 .. 64; |
| -- for x'size use 12; |
| -- subtype y is x range 0 .. 3; |
| |
| -- Here y has a size clause inherited from x, but normally |
| -- it does not apply, and y'size is 2. However, y'VADS_Size |
| -- is indeed 12 and not 2. |
| |
| if Present (S) |
| and then Is_OK_Static_Expression (Expression (S)) |
| then |
| Fold_Uint (N, Expr_Value (Expression (S)), True); |
| |
| -- If no size is specified, then we simply use the object |
| -- size in the VADS_Size case (e.g. Natural'Size is equal |
| -- to Integer'Size, not one less). |
| |
| else |
| Fold_Uint (N, Esize (P_TypeA), True); |
| end if; |
| end; |
| |
| -- Normal case (Size) in which case we want the RM_Size |
| |
| else |
| Fold_Uint (N, |
| RM_Size (P_TypeA), |
| Static and then Is_Discrete_Type (P_TypeA)); |
| end if; |
| end if; |
| end Size; |
| |
| ----------- |
| -- Small -- |
| ----------- |
| |
| when Attribute_Small => |
| |
| -- The floating-point case is present only for Ada 83 compatability. |
| -- Note that strictly this is an illegal addition, since we are |
| -- extending an Ada 95 defined attribute, but we anticipate an |
| -- ARG ruling that will permit this. |
| |
| if Is_Floating_Point_Type (P_Type) then |
| |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Small = 2.0**(-T'Emax - 1) |
| |
| -- where |
| |
| -- T'Emax = 4 * T'Mantissa |
| |
| Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static); |
| |
| -- Normal Ada 95 fixed-point case |
| |
| else |
| Fold_Ureal (N, Small_Value (P_Type), True); |
| end if; |
| |
| ----------------- |
| -- Stream_Size -- |
| ----------------- |
| |
| when Attribute_Stream_Size => |
| null; |
| |
| ---------- |
| -- Succ -- |
| ---------- |
| |
| when Attribute_Succ => Succ : |
| begin |
| -- Floating-point case |
| |
| if Is_Floating_Point_Type (P_Type) then |
| Fold_Ureal (N, |
| Eval_Fat.Succ (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| -- Fixed-point case |
| |
| elsif Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal (N, |
| Expr_Value_R (E1) + Small_Value (P_Type), Static); |
| |
| -- Modular integer case (wraps) |
| |
| elsif Is_Modular_Integer_Type (P_Type) then |
| Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static); |
| |
| -- Other scalar cases |
| |
| else |
| pragma Assert (Is_Scalar_Type (P_Type)); |
| |
| if Is_Enumeration_Type (P_Type) |
| and then Expr_Value (E1) = |
| Expr_Value (Type_High_Bound (P_Base_Type)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "Succ of `&''Last`", |
| CE_Overflow_Check_Failed, |
| Ent => P_Base_Type, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| else |
| Fold_Uint (N, Expr_Value (E1) + 1, Static); |
| end if; |
| end if; |
| end Succ; |
| |
| ---------------- |
| -- Truncation -- |
| ---------------- |
| |
| when Attribute_Truncation => |
| Fold_Ureal (N, |
| Eval_Fat.Truncation (P_Root_Type, Expr_Value_R (E1)), Static); |
| |
| ---------------- |
| -- Type_Class -- |
| ---------------- |
| |
| when Attribute_Type_Class => Type_Class : declare |
| Typ : constant Entity_Id := Underlying_Type (P_Base_Type); |
| Id : RE_Id; |
| |
| begin |
| if Is_Descendent_Of_Address (Typ) then |
| Id := RE_Type_Class_Address; |
| |
| elsif Is_Enumeration_Type (Typ) then |
| Id := RE_Type_Class_Enumeration; |
| |
| elsif Is_Integer_Type (Typ) then |
| Id := RE_Type_Class_Integer; |
| |
| elsif Is_Fixed_Point_Type (Typ) then |
| Id := RE_Type_Class_Fixed_Point; |
| |
| elsif Is_Floating_Point_Type (Typ) then |
| Id := RE_Type_Class_Floating_Point; |
| |
| elsif Is_Array_Type (Typ) then |
| Id := RE_Type_Class_Array; |
| |
| elsif Is_Record_Type (Typ) then |
| Id := RE_Type_Class_Record; |
| |
| elsif Is_Access_Type (Typ) then |
| Id := RE_Type_Class_Access; |
| |
| elsif Is_Enumeration_Type (Typ) then |
| Id := RE_Type_Class_Enumeration; |
| |
| elsif Is_Task_Type (Typ) then |
| Id := RE_Type_Class_Task; |
| |
| -- We treat protected types like task types. It would make more |
| -- sense to have another enumeration value, but after all the |
| -- whole point of this feature is to be exactly DEC compatible, |
| -- and changing the type Type_Clas would not meet this requirement. |
| |
| elsif Is_Protected_Type (Typ) then |
| Id := RE_Type_Class_Task; |
| |
| -- Not clear if there are any other possibilities, but if there |
| -- are, then we will treat them as the address case. |
| |
| else |
| Id := RE_Type_Class_Address; |
| end if; |
| |
| Rewrite (N, New_Occurrence_Of (RTE (Id), Loc)); |
| end Type_Class; |
| |
| ----------------------- |
| -- Unbiased_Rounding -- |
| ----------------------- |
| |
| when Attribute_Unbiased_Rounding => |
| Fold_Ureal (N, |
| Eval_Fat.Unbiased_Rounding (P_Root_Type, Expr_Value_R (E1)), |
| Static); |
| |
| ------------------------- |
| -- Unconstrained_Array -- |
| ------------------------- |
| |
| when Attribute_Unconstrained_Array => Unconstrained_Array : declare |
| Typ : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| Rewrite (N, New_Occurrence_Of ( |
| Boolean_Literals ( |
| Is_Array_Type (P_Type) |
| and then not Is_Constrained (Typ)), Loc)); |
| |
| -- Analyze and resolve as boolean, note that this attribute is |
| -- a static attribute in GNAT. |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| Static := True; |
| end Unconstrained_Array; |
| |
| --------------- |
| -- VADS_Size -- |
| --------------- |
| |
| -- Processing is shared with Size |
| |
| --------- |
| -- Val -- |
| --------- |
| |
| when Attribute_Val => Val : |
| begin |
| if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type)) |
| or else |
| Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "Val expression out of range", |
| CE_Range_Check_Failed, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| |
| else |
| Fold_Uint (N, Expr_Value (E1), Static); |
| end if; |
| end Val; |
| |
| ---------------- |
| -- Value_Size -- |
| ---------------- |
| |
| -- The Value_Size attribute for a type returns the RM size of the |
| -- type. This an always be folded for scalar types, and can also |
| -- be folded for non-scalar types if the size is set. |
| |
| when Attribute_Value_Size => Value_Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if RM_Size (P_TypeA) /= Uint_0 then |
| Fold_Uint (N, RM_Size (P_TypeA), True); |
| end if; |
| |
| end Value_Size; |
| |
| ------------- |
| -- Version -- |
| ------------- |
| |
| -- Version can never be static |
| |
| when Attribute_Version => |
| null; |
| |
| ---------------- |
| -- Wide_Image -- |
| ---------------- |
| |
| -- Wide_Image is a scalar attribute, but is never static, because it |
| -- is not a static function (having a non-scalar argument (RM 4.9(22)) |
| |
| when Attribute_Wide_Image => |
| null; |
| |
| --------------------- |
| -- Wide_Wide_Image -- |
| --------------------- |
| |
| -- Wide_Wide_Image is a scalar attribute but is never static, because it |
| -- is not a static function (having a non-scalar argument (RM 4.9(22)). |
| |
| when Attribute_Wide_Wide_Image => |
| null; |
| |
| --------------------- |
| -- Wide_Wide_Width -- |
| --------------------- |
| |
| -- Processing for Wide_Wide_Width is combined with Width |
| |
| ---------------- |
| -- Wide_Width -- |
| ---------------- |
| |
| -- Processing for Wide_Width is combined with Width |
| |
| ----------- |
| -- Width -- |
| ----------- |
| |
| -- This processing also handles the case of Wide_[Wide_]Width |
| |
| when Attribute_Width | |
| Attribute_Wide_Width | |
| Attribute_Wide_Wide_Width => Width : |
| begin |
| if Compile_Time_Known_Bounds (P_Type) then |
| |
| -- Floating-point types |
| |
| if Is_Floating_Point_Type (P_Type) then |
| |
| -- Width is zero for a null range (RM 3.5 (38)) |
| |
| if Expr_Value_R (Type_High_Bound (P_Type)) < |
| Expr_Value_R (Type_Low_Bound (P_Type)) |
| then |
| Fold_Uint (N, Uint_0, True); |
| |
| else |
| -- For floating-point, we have +N.dddE+nnn where length |
| -- of ddd is determined by type'Digits - 1, but is one |
| -- if Digits is one (RM 3.5 (33)). |
| |
| -- nnn is set to 2 for Short_Float and Float (32 bit |
| -- floats), and 3 for Long_Float and Long_Long_Float. |
| -- For machines where Long_Long_Float is the IEEE |
| -- extended precision type, the exponent takes 4 digits. |
| |
| declare |
| Len : Int := |
| Int'Max (2, UI_To_Int (Digits_Value (P_Type))); |
| |
| begin |
| if Esize (P_Type) <= 32 then |
| Len := Len + 6; |
| elsif Esize (P_Type) = 64 then |
| Len := Len + 7; |
| else |
| Len := Len + 8; |
| end if; |
| |
| Fold_Uint (N, UI_From_Int (Len), True); |
| end; |
| end if; |
| |
| -- Fixed-point types |
| |
| elsif Is_Fixed_Point_Type (P_Type) then |
| |
| -- Width is zero for a null range (RM 3.5 (38)) |
| |
| if Expr_Value (Type_High_Bound (P_Type)) < |
| Expr_Value (Type_Low_Bound (P_Type)) |
| then |
| Fold_Uint (N, Uint_0, True); |
| |
| -- The non-null case depends on the specific real type |
| |
| else |
| -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34)) |
| |
| Fold_Uint |
| (N, UI_From_Int (Fore_Value + 1 + Aft_Value), True); |
| end if; |
| |
| -- Discrete types |
| |
| else |
| declare |
| R : constant Entity_Id := Root_Type (P_Type); |
| Lo : constant Uint := |
| Expr_Value (Type_Low_Bound (P_Type)); |
| Hi : constant Uint := |
| Expr_Value (Type_High_Bound (P_Type)); |
| W : Nat; |
| Wt : Nat; |
| T : Uint; |
| L : Node_Id; |
| C : Character; |
| |
| begin |
| -- Empty ranges |
| |
| if Lo > Hi then |
| W := 0; |
| |
| -- Width for types derived from Standard.Character |
| -- and Standard.Wide_[Wide_]Character. |
| |
| elsif R = Standard_Character |
| or else R = Standard_Wide_Character |
| or else R = Standard_Wide_Wide_Character |
| then |
| W := 0; |
| |
| -- Set W larger if needed |
| |
| for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop |
| |
| -- All wide characters look like Hex_hhhhhhhh |
| |
| if J > 255 then |
| W := 12; |
| |
| else |
| C := Character'Val (J); |
| |
| -- Test for all cases where Character'Image |
| -- yields an image that is longer than three |
| -- characters. First the cases of Reserved_xxx |
| -- names (length = 12). |
| |
| case C is |
| when Reserved_128 | Reserved_129 | |
| Reserved_132 | Reserved_153 |
| |
| => Wt := 12; |
| |
| when BS | HT | LF | VT | FF | CR | |
| SO | SI | EM | FS | GS | RS | |
| US | RI | MW | ST | PM |
| |
| => Wt := 2; |
| |
| when NUL | SOH | STX | ETX | EOT | |
| ENQ | ACK | BEL | DLE | DC1 | |
| DC2 | DC3 | DC4 | NAK | SYN | |
| ETB | CAN | SUB | ESC | DEL | |
| BPH | NBH | NEL | SSA | ESA | |
| HTS | HTJ | VTS | PLD | PLU | |
| SS2 | SS3 | DCS | PU1 | PU2 | |
| STS | CCH | SPA | EPA | SOS | |
| SCI | CSI | OSC | APC |
| |
| => Wt := 3; |
| |
| when Space .. Tilde | |
| No_Break_Space .. LC_Y_Diaeresis |
| |
| => Wt := 3; |
| end case; |
| |
| W := Int'Max (W, Wt); |
| end if; |
| end loop; |
| |
| -- Width for types derived from Standard.Boolean |
| |
| elsif R = Standard_Boolean then |
| if Lo = 0 then |
| W := 5; -- FALSE |
| else |
| W := 4; -- TRUE |
| end if; |
| |
| -- Width for integer types |
| |
| elsif Is_Integer_Type (P_Type) then |
| T := UI_Max (abs Lo, abs Hi); |
| |
| W := 2; |
| while T >= 10 loop |
| W := W + 1; |
| T := T / 10; |
| end loop; |
| |
| -- Only remaining possibility is user declared enum type |
| |
| else |
| pragma Assert (Is_Enumeration_Type (P_Type)); |
| |
| W := 0; |
| L := First_Literal (P_Type); |
| |
| while Present (L) loop |
| |
| -- Only pay attention to in range characters |
| |
| if Lo <= Enumeration_Pos (L) |
| and then Enumeration_Pos (L) <= Hi |
| then |
| -- For Width case, use decoded name |
| |
| if Id = Attribute_Width then |
| Get_Decoded_Name_String (Chars (L)); |
| Wt := Nat (Name_Len); |
| |
| -- For Wide_[Wide_]Width, use encoded name, and |
| -- then adjust for the encoding. |
| |
| else |
| Get_Name_String (Chars (L)); |
| |
| -- Character literals are always of length 3 |
| |
| if Name_Buffer (1) = 'Q' then |
| Wt := 3; |
| |
| -- Otherwise loop to adjust for upper/wide chars |
| |
| else |
| Wt := Nat (Name_Len); |
| |
| for J in 1 .. Name_Len loop |
| if Name_Buffer (J) = 'U' then |
| Wt := Wt - 2; |
| elsif Name_Buffer (J) = 'W' then |
| Wt := Wt - 4; |
| end if; |
| end loop; |
| end if; |
| end if; |
| |
| W := Int'Max (W, Wt); |
| end if; |
| |
| Next_Literal (L); |
| end loop; |
| end if; |
| |
| Fold_Uint (N, UI_From_Int (W), True); |
| end; |
| end if; |
| end if; |
| end Width; |
| |
| -- The following attributes can never be folded, and furthermore we |
| -- should not even have entered the case statement for any of these. |
| -- Note that in some cases, the values have already been folded as |
| -- a result of the processing in Analyze_Attribute. |
| |
| when Attribute_Abort_Signal | |
| Attribute_Access | |
| Attribute_Address | |
| Attribute_Address_Size | |
| Attribute_Asm_Input | |
| Attribute_Asm_Output | |
| Attribute_Base | |
| Attribute_Bit_Order | |
| Attribute_Bit_Position | |
| Attribute_Callable | |
| Attribute_Caller | |
| Attribute_Class | |
| Attribute_Code_Address | |
| Attribute_Count | |
| Attribute_Default_Bit_Order | |
| Attribute_Elaborated | |
| Attribute_Elab_Body | |
| Attribute_Elab_Spec | |
| Attribute_External_Tag | |
| Attribute_First_Bit | |
| Attribute_Input | |
| Attribute_Last_Bit | |
| Attribute_Maximum_Alignment | |
| Attribute_Output | |
| Attribute_Partition_ID | |
| Attribute_Pool_Address | |
| Attribute_Position | |
| Attribute_Read | |
| Attribute_Storage_Pool | |
| Attribute_Storage_Size | |
| Attribute_Storage_Unit | |
| Attribute_Tag | |
| Attribute_Target_Name | |
| Attribute_Terminated | |
| Attribute_To_Address | |
| Attribute_UET_Address | |
| Attribute_Unchecked_Access | |
| Attribute_Universal_Literal_String | |
| Attribute_Unrestricted_Access | |
| Attribute_Valid | |
| Attribute_Value | |
| Attribute_Wchar_T_Size | |
| Attribute_Wide_Value | |
| Attribute_Wide_Wide_Value | |
| Attribute_Word_Size | |
| Attribute_Write => |
| |
| raise Program_Error; |
| end case; |
| |
| -- At the end of the case, one more check. If we did a static evaluation |
| -- so that the result is now a literal, then set Is_Static_Expression |
| -- in the constant only if the prefix type is a static subtype. For |
| -- non-static subtypes, the folding is still OK, but not static. |
| |
| -- An exception is the GNAT attribute Constrained_Array which is |
| -- defined to be a static attribute in all cases. |
| |
| if Nkind (N) = N_Integer_Literal |
| or else Nkind (N) = N_Real_Literal |
| or else Nkind (N) = N_Character_Literal |
| or else Nkind (N) = N_String_Literal |
| or else (Is_Entity_Name (N) |
| and then Ekind (Entity (N)) = E_Enumeration_Literal) |
| then |
| Set_Is_Static_Expression (N, Static); |
| |
| -- If this is still an attribute reference, then it has not been folded |
| -- and that means that its expressions are in a non-static context. |
| |
| elsif Nkind (N) = N_Attribute_Reference then |
| Check_Expressions; |
| |
| -- Note: the else case not covered here are odd cases where the |
| -- processing has transformed the attribute into something other |
| -- than a constant. Nothing more to do in such cases. |
| |
| else |
| null; |
| end if; |
| |
| end Eval_Attribute; |
| |
| ------------------------------ |
| -- Is_Anonymous_Tagged_Base -- |
| ------------------------------ |
| |
| function Is_Anonymous_Tagged_Base |
| (Anon : Entity_Id; |
| Typ : Entity_Id) |
| return Boolean |
| is |
| begin |
| return |
| Anon = Current_Scope |
| and then Is_Itype (Anon) |
| and then Associated_Node_For_Itype (Anon) = Parent (Typ); |
| end Is_Anonymous_Tagged_Base; |
| |
| ----------------------- |
| -- Resolve_Attribute -- |
| ----------------------- |
| |
| procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| P : constant Node_Id := Prefix (N); |
| Aname : constant Name_Id := Attribute_Name (N); |
| Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname); |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Index : Interp_Index; |
| It : Interp; |
| Nom_Subt : Entity_Id; |
| |
| procedure Accessibility_Message; |
| -- Error, or warning within an instance, if the static accessibility |
| -- rules of 3.10.2 are violated. |
| |
| --------------------------- |
| -- Accessibility_Message -- |
| --------------------------- |
| |
| procedure Accessibility_Message is |
| Indic : Node_Id := Parent (Parent (N)); |
| |
| begin |
| -- In an instance, this is a runtime check, but one we |
| -- know will fail, so generate an appropriate warning. |
| |
| if In_Instance_Body then |
| Error_Msg_N |
| ("?non-local pointer cannot point to local object", P); |
| Error_Msg_N |
| ("\?Program_Error will be raised at run time", P); |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, Typ); |
| return; |
| |
| else |
| Error_Msg_N |
| ("non-local pointer cannot point to local object", P); |
| |
| -- Check for case where we have a missing access definition |
| |
| if Is_Record_Type (Current_Scope) |
| and then |
| (Nkind (Parent (N)) = N_Discriminant_Association |
| or else |
| Nkind (Parent (N)) = N_Index_Or_Discriminant_Constraint) |
| then |
| Indic := Parent (Parent (N)); |
| while Present (Indic) |
| and then Nkind (Indic) /= N_Subtype_Indication |
| loop |
| Indic := Parent (Indic); |
| end loop; |
| |
| if Present (Indic) then |
| Error_Msg_NE |
| ("\use an access definition for" & |
| " the access discriminant of&", N, |
| Entity (Subtype_Mark (Indic))); |
| end if; |
| end if; |
| end if; |
| end Accessibility_Message; |
| |
| -- Start of processing for Resolve_Attribute |
| |
| begin |
| -- If error during analysis, no point in continuing, except for |
| -- array types, where we get better recovery by using unconstrained |
| -- indices than nothing at all (see Check_Array_Type). |
| |
| if Error_Posted (N) |
| and then Attr_Id /= Attribute_First |
| and then Attr_Id /= Attribute_Last |
| and then Attr_Id /= Attribute_Length |
| and then Attr_Id /= Attribute_Range |
| then |
| return; |
| end if; |
| |
| -- If attribute was universal type, reset to actual type |
| |
| if Etype (N) = Universal_Integer |
| or else Etype (N) = Universal_Real |
| then |
| Set_Etype (N, Typ); |
| end if; |
| |
| -- Remaining processing depends on attribute |
| |
| case Attr_Id is |
| |
| ------------ |
| -- Access -- |
| ------------ |
| |
| -- For access attributes, if the prefix denotes an entity, it is |
| -- interpreted as a name, never as a call. It may be overloaded, |
| -- in which case resolution uses the profile of the context type. |
| -- Otherwise prefix must be resolved. |
| |
| when Attribute_Access |
| | Attribute_Unchecked_Access |
| | Attribute_Unrestricted_Access => |
| |
| if Is_Variable (P) then |
| Note_Possible_Modification (P); |
| end if; |
| |
| if Is_Entity_Name (P) then |
| if Is_Overloaded (P) then |
| Get_First_Interp (P, Index, It); |
| |
| while Present (It.Nam) loop |
| |
| if Type_Conformant (Designated_Type (Typ), It.Nam) then |
| Set_Entity (P, It.Nam); |
| |
| -- The prefix is definitely NOT overloaded anymore |
| -- at this point, so we reset the Is_Overloaded |
| -- flag to avoid any confusion when reanalyzing |
| -- the node. |
| |
| Set_Is_Overloaded (P, False); |
| Generate_Reference (Entity (P), P); |
| exit; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| |
| -- If it is a subprogram name or a type, there is nothing |
| -- to resolve. |
| |
| elsif not Is_Overloadable (Entity (P)) |
| and then not Is_Type (Entity (P)) |
| then |
| Resolve (P); |
| end if; |
| |
| Error_Msg_Name_1 := Aname; |
| |
| if not Is_Entity_Name (P) then |
| null; |
| |
| elsif Is_Abstract (Entity (P)) |
| and then Is_Overloadable (Entity (P)) |
| then |
| Error_Msg_N ("prefix of % attribute cannot be abstract", P); |
| Set_Etype (N, Any_Type); |
| |
| elsif Convention (Entity (P)) = Convention_Intrinsic then |
| if Ekind (Entity (P)) = E_Enumeration_Literal then |
| Error_Msg_N |
| ("prefix of % attribute cannot be enumeration literal", |
| P); |
| else |
| Error_Msg_N |
| ("prefix of % attribute cannot be intrinsic", P); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| |
| elsif Is_Thread_Body (Entity (P)) then |
| Error_Msg_N |
| ("prefix of % attribute cannot be a thread body", P); |
| end if; |
| |
| -- Assignments, return statements, components of aggregates, |
| -- generic instantiations will require convention checks if |
| -- the type is an access to subprogram. Given that there will |
| -- also be accessibility checks on those, this is where the |
| -- checks can eventually be centralized ??? |
| |
| if Ekind (Btyp) = E_Access_Subprogram_Type |
| or else |
| Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type |
| or else |
| Ekind (Btyp) = E_Anonymous_Access_Protected_Subprogram_Type |
| then |
| if Convention (Btyp) /= Convention (Entity (P)) then |
| Error_Msg_N |
| ("subprogram has invalid convention for context", P); |
| |
| else |
| Check_Subtype_Conformant |
| (New_Id => Entity (P), |
| Old_Id => Designated_Type (Btyp), |
| Err_Loc => P); |
| end if; |
| |
| if Attr_Id = Attribute_Unchecked_Access then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("attribute% cannot be applied to a subprogram", P); |
| |
| elsif Aname = Name_Unrestricted_Access then |
| null; -- Nothing to check |
| |
| -- Check the static accessibility rule of 3.10.2(32). |
| -- This rule also applies within the private part of an |
| -- instantiation. This rule does not apply to anonymous |
| -- access-to-subprogram types (Ada 2005). |
| |
| elsif Attr_Id = Attribute_Access |
| and then not In_Instance_Body |
| and then Subprogram_Access_Level (Entity (P)) > |
| Type_Access_Level (Btyp) |
| and then Ekind (Btyp) /= |
| E_Anonymous_Access_Subprogram_Type |
| and then Ekind (Btyp) /= |
| E_Anonymous_Access_Protected_Subprogram_Type |
| then |
| Error_Msg_N |
| ("subprogram must not be deeper than access type", P); |
| |
| -- Check the restriction of 3.10.2(32) that disallows the |
| -- access attribute within a generic body when the ultimate |
| -- ancestor of the type of the attribute is declared outside |
| -- of the generic unit and the subprogram is declared within |
| -- that generic unit. This includes any such attribute that |
| -- occurs within the body of a generic unit that is a child |
| -- of the generic unit where the subprogram is declared. |
| -- The rule also prohibits applying the attibute when the |
| -- access type is a generic formal access type (since the |
| -- level of the actual type is not known). This restriction |
| -- does not apply when the attribute type is an anonymous |
| -- access-to-subprogram type. Note that this check was |
| -- revised by AI-229, because the originally Ada 95 rule |
| -- was too lax. The original rule only applied when the |
| -- subprogram was declared within the body of the generic, |
| -- which allowed the possibility of dangling references). |
| -- The rule was also too strict in some case, in that it |
| -- didn't permit the access to be declared in the generic |
| -- spec, whereas the revised rule does (as long as it's not |
| -- a formal type). |
| |
| -- There are a couple of subtleties of the test for applying |
| -- the check that are worth noting. First, we only apply it |
| -- when the levels of the subprogram and access type are the |
| -- same (the case where the subprogram is statically deeper |
| -- was applied above, and the case where the type is deeper |
| -- is always safe). Second, we want the check to apply |
| -- within nested generic bodies and generic child unit |
| -- bodies, but not to apply to an attribute that appears in |
| -- the generic unit's specification. This is done by testing |
| -- that the attribute's innermost enclosing generic body is |
| -- not the same as the innermost generic body enclosing the |
| -- generic unit where the subprogram is declared (we don't |
| -- want the check to apply when the access attribute is in |
| -- the spec and there's some other generic body enclosing |
| -- generic). Finally, there's no point applying the check |
| -- when within an instance, because any violations will |
| -- have been caught by the compilation of the generic unit. |
| |
| elsif Attr_Id = Attribute_Access |
| and then not In_Instance |
| and then Present (Enclosing_Generic_Unit (Entity (P))) |
| and then Present (Enclosing_Generic_Body (N)) |
| and then Enclosing_Generic_Body (N) /= |
| Enclosing_Generic_Body |
| (Enclosing_Generic_Unit (Entity (P))) |
| and then Subprogram_Access_Level (Entity (P)) = |
| Type_Access_Level (Btyp) |
| and then Ekind (Btyp) /= |
| E_Anonymous_Access_Subprogram_Type |
| and then Ekind (Btyp) /= |
| E_Anonymous_Access_Protected_Subprogram_Type |
| then |
| -- The attribute type's ultimate ancestor must be |
| -- declared within the same generic unit as the |
| -- subprogram is declared. The error message is |
| -- specialized to say "ancestor" for the case where |
| -- the access type is not its own ancestor, since |
| -- saying simply "access type" would be very confusing. |
| |
| if Enclosing_Generic_Unit (Entity (P)) /= |
| Enclosing_Generic_Unit (Root_Type (Btyp)) |
| then |
| if Root_Type (Btyp) = Btyp then |
| Error_Msg_N |
| ("access type must not be outside generic unit", |
| N); |
| else |
| Error_Msg_N |
| ("ancestor access type must not be outside " & |
| "generic unit", N); |
| end if; |
| |
| -- If the ultimate ancestor of the attribute's type is |
| -- a formal type, then the attribute is illegal because |
| -- the actual type might be declared at a higher level. |
| -- The error message is specialized to say "ancestor" |
| -- for the case where the access type is not its own |
| -- ancestor, since saying simply "access type" would be |
| -- very confusing. |
| |
| elsif Is_Generic_Type (Root_Type (Btyp)) then |
| if Root_Type (Btyp) = Btyp then |
| Error_Msg_N |
| ("access type must not be a generic formal type", |
| N); |
| else |
| Error_Msg_N |
| ("ancestor access type must not be a generic " & |
| "formal type", N); |
| end if; |
| end if; |
| end if; |
| end if; |
| |
| -- If this is a renaming, an inherited operation, or a |
| -- subprogram instance, use the original entity. |
| |
| if Is_Entity_Name (P) |
| and then Is_Overloadable (Entity (P)) |
| and then Present (Alias (Entity (P))) |
| then |
| Rewrite (P, |
| New_Occurrence_Of (Alias (Entity (P)), Sloc (P))); |
| end if; |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Is_Overloadable (Entity (Selector_Name (P))) |
| then |
| -- Protected operation. If operation is overloaded, must |
| -- disambiguate. Prefix that denotes protected object itself |
| -- is resolved with its own type. |
| |
| if Attr_Id = Attribute_Unchecked_Access then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("attribute% cannot be applied to protected operation", P); |
| end if; |
| |
| Resolve (Prefix (P)); |
| Generate_Reference (Entity (Selector_Name (P)), P); |
| |
| elsif Is_Overloaded (P) then |
| |
| -- Use the designated type of the context to disambiguate |
| -- Note that this was not strictly conformant to Ada 95, |
| -- but was the implementation adopted by most Ada 95 compilers. |
| -- The use of the context type to resolve an Access attribute |
| -- reference is now mandated in AI-235 for Ada 2005. |
| |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (P, Index, It); |
| while Present (It.Typ) loop |
| if Covers (Designated_Type (Typ), It.Typ) then |
| Resolve (P, It.Typ); |
| exit; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| else |
| Resolve (P); |
| end if; |
| |
| -- X'Access is illegal if X denotes a constant and the access |
| -- type is access-to-variable. Same for 'Unchecked_Access. |
| -- The rule does not apply to 'Unrestricted_Access. |
| |
| if not (Ekind (Btyp) = E_Access_Subprogram_Type |
| or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type |
| or else (Is_Record_Type (Btyp) and then |
| Present (Corresponding_Remote_Type (Btyp))) |
| or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type |
| or else Ekind (Btyp) |
| = E_Anonymous_Access_Protected_Subprogram_Type |
| or else Is_Access_Constant (Btyp) |
| or else Is_Variable (P) |
| or else Attr_Id = Attribute_Unrestricted_Access) |
| then |
| if Comes_From_Source (N) then |
| Error_Msg_N ("access-to-variable designates constant", P); |
| end if; |
| end if; |
| |
| if (Attr_Id = Attribute_Access |
| or else |
| Attr_Id = Attribute_Unchecked_Access) |
| and then (Ekind (Btyp) = E_General_Access_Type |
| or else Ekind (Btyp) = E_Anonymous_Access_Type) |
| then |
| -- Ada 2005 (AI-230): Check the accessibility of anonymous |
| -- access types in record and array components. For a |
| -- component definition the level is the same of the |
| -- enclosing composite type. |
| |
| if Ada_Version >= Ada_05 |
| and then Is_Local_Anonymous_Access (Btyp) |
| and then Object_Access_Level (P) > Type_Access_Level (Btyp) |
| then |
| -- In an instance, this is a runtime check, but one we |
| -- know will fail, so generate an appropriate warning. |
| |
| if In_Instance_Body then |
| Error_Msg_N |
| ("?non-local pointer cannot point to local object", P); |
| Error_Msg_N |
| ("\?Program_Error will be raised at run time", P); |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, Typ); |
| else |
| Error_Msg_N |
| ("non-local pointer cannot point to local object", P); |
| end if; |
| end if; |
| |
| if Is_Dependent_Component_Of_Mutable_Object (P) then |
| Error_Msg_N |
| ("illegal attribute for discriminant-dependent component", |
| P); |
| end if; |
| |
| -- Check the static matching rule of 3.10.2(27). The |
| -- nominal subtype of the prefix must statically |
| -- match the designated type. |
| |
| Nom_Subt := Etype (P); |
| |
| if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then |
| Nom_Subt := Etype (Nom_Subt); |
| end if; |
| |
| if Is_Tagged_Type (Designated_Type (Typ)) then |
| |
| -- If the attribute is in the context of an access |
| -- parameter, then the prefix is allowed to be of |
| -- the class-wide type (by AI-127). |
| |
| if Ekind (Typ) = E_Anonymous_Access_Type then |
| if not Covers (Designated_Type (Typ), Nom_Subt) |
| and then not Covers (Nom_Subt, Designated_Type (Typ)) |
| then |
| declare |
| Desig : Entity_Id; |
| |
| begin |
| Desig := Designated_Type (Typ); |
| |
| if Is_Class_Wide_Type (Desig) then |
| Desig := Etype (Desig); |
| end if; |
| |
| if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then |
| null; |
| |
| else |
| Error_Msg_NE |
| ("type of prefix: & not compatible", |
| P, Nom_Subt); |
| Error_Msg_NE |
| ("\with &, the expected designated type", |
| P, Designated_Type (Typ)); |
| end if; |
| end; |
| end if; |
| |
| elsif not Covers (Designated_Type (Typ), Nom_Subt) |
| or else |
| (not Is_Class_Wide_Type (Designated_Type (Typ)) |
| and then Is_Class_Wide_Type (Nom_Subt)) |
| then |
| Error_Msg_NE |
| ("type of prefix: & is not covered", P, Nom_Subt); |
| Error_Msg_NE |
| ("\by &, the expected designated type" & |
| " ('R'M 3.10.2 (27))", P, Designated_Type (Typ)); |
| end if; |
| |
| if Is_Class_Wide_Type (Designated_Type (Typ)) |
| and then Has_Discriminants (Etype (Designated_Type (Typ))) |
| and then Is_Constrained (Etype (Designated_Type (Typ))) |
| and then Designated_Type (Typ) /= Nom_Subt |
| then |
| Apply_Discriminant_Check |
| (N, Etype (Designated_Type (Typ))); |
| end if; |
| |
| elsif not Subtypes_Statically_Match |
| (Designated_Type (Base_Type (Typ)), Nom_Subt) |
| and then |
| not (Has_Discriminants (Designated_Type (Typ)) |
| and then |
| not Is_Constrained |
| (Designated_Type (Base_Type (Typ)))) |
| then |
| Error_Msg_N |
| ("object subtype must statically match " |
| & "designated subtype", P); |
| |
| if Is_Entity_Name (P) |
| and then Is_Array_Type (Designated_Type (Typ)) |
| then |
| |
| declare |
| D : constant Node_Id := Declaration_Node (Entity (P)); |
| |
| begin |
| Error_Msg_N ("aliased object has explicit bounds?", |
| D); |
| Error_Msg_N ("\declare without bounds" |
| & " (and with explicit initialization)?", D); |
| Error_Msg_N ("\for use with unconstrained access?", D); |
| end; |
| end if; |
| end if; |
| |
| -- Check the static accessibility rule of 3.10.2(28). |
| -- Note that this check is not performed for the |
| -- case of an anonymous access type, since the access |
| -- attribute is always legal in such a context. |
| |
| if Attr_Id /= Attribute_Unchecked_Access |
| and then Object_Access_Level (P) > Type_Access_Level (Btyp) |
| and then Ekind (Btyp) = E_General_Access_Type |
| then |
| Accessibility_Message; |
| return; |
| end if; |
| end if; |
| |
| if Ekind (Btyp) = E_Access_Protected_Subprogram_Type |
| or else |
| Ekind (Btyp) = E_Anonymous_Access_Protected_Subprogram_Type |
| then |
| if Is_Entity_Name (P) |
| and then not Is_Protected_Type (Scope (Entity (P))) |
| then |
| Error_Msg_N ("context requires a protected subprogram", P); |
| |
| -- Check accessibility of protected object against that |
| -- of the access type, but only on user code, because |
| -- the expander creates access references for handlers. |
| -- If the context is an anonymous_access_to_protected, |
| -- there are no accessibility checks either. |
| |
| elsif Object_Access_Level (P) > Type_Access_Level (Btyp) |
| and then Comes_From_Source (N) |
| and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type |
| and then No (Original_Access_Type (Typ)) |
| then |
| Accessibility_Message; |
| return; |
| end if; |
| |
| elsif (Ekind (Btyp) = E_Access_Subprogram_Type |
| or else |
| Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type) |
| and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type |
| then |
| Error_Msg_N ("context requires a non-protected subprogram", P); |
| end if; |
| |
| -- The context cannot be a pool-specific type, but this is a |
| -- legality rule, not a resolution rule, so it must be checked |
| -- separately, after possibly disambiguation (see AI-245). |
| |
| if Ekind (Btyp) = E_Access_Type |
| and then Attr_Id /= Attribute_Unrestricted_Access |
| then |
| Wrong_Type (N, Typ); |
| end if; |
| |
| Set_Etype (N, Typ); |
| |
| -- Check for incorrect atomic/volatile reference (RM C.6(12)) |
| |
| if Attr_Id /= Attribute_Unrestricted_Access then |
| if Is_Atomic_Object (P) |
| and then not Is_Atomic (Designated_Type (Typ)) |
| then |
| Error_Msg_N |
| ("access to atomic object cannot yield access-to-" & |
| "non-atomic type", P); |
| |
| elsif Is_Volatile_Object (P) |
| and then not Is_Volatile (Designated_Type (Typ)) |
| then |
| Error_Msg_N |
| ("access to volatile object cannot yield access-to-" & |
| "non-volatile type", P); |
| end if; |
| end if; |
| |
| ------------- |
| -- Address -- |
| ------------- |
| |
| -- Deal with resolving the type for Address attribute, overloading |
| -- is not permitted here, since there is no context to resolve it. |
| |
| when Attribute_Address | Attribute_Code_Address => |
| |
| -- To be safe, assume that if the address of a variable is taken, |
| -- it may be modified via this address, so note modification. |
| |
| if Is_Variable (P) then |
| Note_Possible_Modification (P); |
| end if; |
| |
| if Nkind (P) in N_Subexpr |
| and then Is_Overloaded (P) |
| then |
| Get_First_Interp (P, Index, It); |
| Get_Next_Interp (Index, It); |
| |
| if Present (It.Nam) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("prefix of % attribute cannot be overloaded", P); |
| return; |
| end if; |
| end if; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Overloadable (Entity (P)) |
| then |
| if not Is_Task_Type (Etype (P)) |
| or else Nkind (P) = N_Explicit_Dereference |
| then |
| Resolve (P); |
| end if; |
| end if; |
| |
| -- If this is the name of a derived subprogram, or that of a |
| -- generic actual, the address is that of the original entity. |
| |
| if Is_Entity_Name (P) |
| and then Is_Overloadable (Entity (P)) |
| and then Present (Alias (Entity (P))) |
| then |
| Rewrite (P, |
| New_Occurrence_Of (Alias (Entity (P)), Sloc (P))); |
| end if; |
| |
| --------------- |
| -- AST_Entry -- |
| --------------- |
| |
| -- Prefix of the AST_Entry attribute is an entry name which must |
| -- not be resolved, since this is definitely not an entry call. |
| |
| when Attribute_AST_Entry => |
| null; |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| -- Prefix of Body_Version attribute can be a subprogram name which |
| -- must not be resolved, since this is not a call. |
| |
| when Attribute_Body_Version => |
| null; |
| |
| ------------ |
| -- Caller -- |
| ------------ |
| |
| -- Prefix of Caller attribute is an entry name which must not |
| -- be resolved, since this is definitely not an entry call. |
| |
| when Attribute_Caller => |
| null; |
| |
| ------------------ |
| -- Code_Address -- |
| ------------------ |
| |
| -- Shares processing with Address attribute |
| |
| ----------- |
| -- Count -- |
| ----------- |
| |
| -- If the prefix of the Count attribute is an entry name it must not |
| -- be resolved, since this is definitely not an entry call. However, |
| -- if it is an element of an entry family, the index itself may |
| -- have to be resolved because it can be a general expression. |
| |
| when Attribute_Count => |
| if Nkind (P) = N_Indexed_Component |
| and then Is_Entity_Name (Prefix (P)) |
| then |
| declare |
| Indx : constant Node_Id := First (Expressions (P)); |
| Fam : constant Entity_Id := Entity (Prefix (P)); |
| begin |
| Resolve (Indx, Entry_Index_Type (Fam)); |
| Apply_Range_Check (Indx, Entry_Index_Type (Fam)); |
| end; |
| end if; |
| |
| ---------------- |
| -- Elaborated -- |
| ---------------- |
| |
| -- Prefix of the Elaborated attribute is a subprogram name which |
| -- must not be resolved, since this is definitely not a call. Note |
| -- that it is a library unit, so it cannot be overloaded here. |
| |
| when Attribute_Elaborated => |
| null; |
| |
| -------------------- |
| -- Mechanism_Code -- |
| -------------------- |
| |
| -- Prefix of the Mechanism_Code attribute is a function name |
| -- which must not be resolved. Should we check for overloaded ??? |
| |
| when Attribute_Mechanism_Code => |
| null; |
| |
| ------------------ |
| -- Partition_ID -- |
| ------------------ |
| |
| -- Most processing is done in sem_dist, after determining the |
| -- context type. Node is rewritten as a conversion to a runtime call. |
| |
| when Attribute_Partition_ID => |
| Process_Partition_Id (N); |
| return; |
| |
| when Attribute_Pool_Address => |
| Resolve (P); |
| |
| ----------- |
| -- Range -- |
| ----------- |
| |
| -- We replace the Range attribute node with a range expression |
| -- whose bounds are the 'First and 'Last attributes applied to the |
| -- same prefix. The reason that we do this transformation here |
| -- instead of in the expander is that it simplifies other parts of |
| -- the semantic analysis which assume that the Range has been |
| -- replaced; thus it must be done even when in semantic-only mode |
| -- (note that the RM specifically mentions this equivalence, we |
| -- take care that the prefix is only evaluated once). |
| |
| when Attribute_Range => Range_Attribute : |
| declare |
| LB : Node_Id; |
| HB : Node_Id; |
| |
| function Check_Discriminated_Prival |
| (N : Node_Id) |
| return Node_Id; |
| -- The range of a private component constrained by a |
| -- discriminant is rewritten to make the discriminant |
| -- explicit. This solves some complex visibility problems |
| -- related to the use of privals. |
| |
| -------------------------------- |
| -- Check_Discriminated_Prival -- |
| -------------------------------- |
| |
| function Check_Discriminated_Prival |
| (N : Node_Id) |
| return Node_Id |
| is |
| begin |
| if Is_Entity_Name (N) |
| and then Ekind (Entity (N)) = E_In_Parameter |
| and then not Within_Init_Proc |
| then |
| return Make_Identifier (Sloc (N), Chars (Entity (N))); |
| else |
| return Duplicate_Subexpr (N); |
| end if; |
| end Check_Discriminated_Prival; |
| |
| -- Start of processing for Range_Attribute |
| |
| begin |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| then |
| Resolve (P); |
| end if; |
| |
| -- Check whether prefix is (renaming of) private component |
| -- of protected type. |
| |
| if Is_Entity_Name (P) |
| and then Comes_From_Source (N) |
| and then Is_Array_Type (Etype (P)) |
| and then Number_Dimensions (Etype (P)) = 1 |
| and then (Ekind (Scope (Entity (P))) = E_Protected_Type |
| or else |
| Ekind (Scope (Scope (Entity (P)))) = |
| E_Protected_Type) |
| then |
| LB := |
| Check_Discriminated_Prival |
| (Type_Low_Bound (Etype (First_Index (Etype (P))))); |
| |
| HB := |
| Check_Discriminated_Prival |
| (Type_High_Bound (Etype (First_Index (Etype (P))))); |
| |
| else |
| HB := |
| Make_Attribute_Reference (Loc, |
| Prefix => Duplicate_Subexpr (P), |
| Attribute_Name => Name_Last, |
| Expressions => Expressions (N)); |
| |
| LB := |
| Make_Attribute_Reference (Loc, |
| Prefix => P, |
| Attribute_Name => Name_First, |
| Expressions => Expressions (N)); |
| end if; |
| |
| -- If the original was marked as Must_Not_Freeze (see code |
| -- in Sem_Ch3.Make_Index), then make sure the rewriting |
| -- does not freeze either. |
| |
| if Must_Not_Freeze (N) then |
| Set_Must_Not_Freeze (HB); |
| Set_Must_Not_Freeze (LB); |
| Set_Must_Not_Freeze (Prefix (HB)); |
| Set_Must_Not_Freeze (Prefix (LB)); |
| end if; |
| |
| if Raises_Constraint_Error (Prefix (N)) then |
| |
| -- Preserve Sloc of prefix in the new bounds, so that |
| -- the posted warning can be removed if we are within |
| -- unreachable code. |
| |
| Set_Sloc (LB, Sloc (Prefix (N))); |
| Set_Sloc (HB, Sloc (Prefix (N))); |
| end if; |
| |
| Rewrite (N, Make_Range (Loc, LB, HB)); |
| Analyze_And_Resolve (N, Typ); |
| |
| -- Normally after resolving attribute nodes, Eval_Attribute |
| -- is called to do any possible static evaluation of the node. |
| -- However, here since the Range attribute has just been |
| -- transformed into a range expression it is no longer an |
| -- attribute node and therefore the call needs to be avoided |
| -- and is accomplished by simply returning from the procedure. |
| |
| return; |
| end Range_Attribute; |
| |
| ----------------- |
| -- UET_Address -- |
| ----------------- |
| |
| -- Prefix must not be resolved in this case, since it is not a |
| -- real entity reference. No action of any kind is require! |
| |
| when Attribute_UET_Address => |
| return; |
| |
| ---------------------- |
| -- Unchecked_Access -- |
| ---------------------- |
| |
| -- Processing is shared with Access |
| |
| ------------------------- |
| -- Unrestricted_Access -- |
| ------------------------- |
| |
| -- Processing is shared with Access |
| |
| --------- |
| -- Val -- |
| --------- |
| |
| -- Apply range check. Note that we did not do this during the |
| -- analysis phase, since we wanted Eval_Attribute to have a |
| -- chance at finding an illegal out of range value. |
| |
| when Attribute_Val => |
| |
| -- Note that we do our own Eval_Attribute call here rather than |
| -- use the common one, because we need to do processing after |
| -- the call, as per above comment. |
| |
| Eval_Attribute (N); |
| |
| -- Eval_Attribute may replace the node with a raise CE, or |
| -- fold it to a constant. Obviously we only apply a scalar |
| -- range check if this did not happen! |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then Attribute_Name (N) = Name_Val |
| then |
| Apply_Scalar_Range_Check (First (Expressions (N)), Btyp); |
| end if; |
| |
| return; |
| |
| ------------- |
| -- Version -- |
| ------------- |
| |
| -- Prefix of Version attribute can be a subprogram name which |
| -- must not be resolved, since this is not a call. |
| |
| when Attribute_Version => |
| null; |
| |
| ---------------------- |
| -- Other Attributes -- |
| ---------------------- |
| |
| -- For other attributes, resolve prefix unless it is a type. If |
| -- the attribute reference itself is a type name ('Base and 'Class) |
| -- then this is only legal within a task or protected record. |
| |
| when others => |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| then |
| Resolve (P); |
| end if; |
| |
| -- If the attribute reference itself is a type name ('Base, |
| -- 'Class) then this is only legal within a task or protected |
| -- record. What is this all about ??? |
| |
| if Is_Entity_Name (N) |
| and then Is_Type (Entity (N)) |
| then |
| if Is_Concurrent_Type (Entity (N)) |
| and then In_Open_Scopes (Entity (P)) |
| then |
| null; |
| else |
| Error_Msg_N |
| ("invalid use of subtype name in expression or call", N); |
| end if; |
| end if; |
| |
| -- For attributes whose argument may be a string, complete |
| -- resolution of argument now. This avoids premature expansion |
| -- (and the creation of transient scopes) before the attribute |
| -- reference is resolved. |
| |
| case Attr_Id is |
| when Attribute_Value => |
| Resolve (First (Expressions (N)), Standard_String); |
| |
| when Attribute_Wide_Value => |
| Resolve (First (Expressions (N)), Standard_Wide_String); |
| |
| when Attribute_Wide_Wide_Value => |
| Resolve (First (Expressions (N)), Standard_Wide_Wide_String); |
| |
| when others => null; |
| end case; |
| end case; |
| |
| -- Normally the Freezing is done by Resolve but sometimes the Prefix |
| -- is not resolved, in which case the freezing must be done now. |
| |
| Freeze_Expression (P); |
| |
| -- Finally perform static evaluation on the attribute reference |
| |
| Eval_Attribute (N); |
| end Resolve_Attribute; |
| |
| -------------------------------- |
| -- Stream_Attribute_Available -- |
| -------------------------------- |
| |
| function Stream_Attribute_Available |
| (Typ : Entity_Id; |
| Nam : TSS_Name_Type; |
| Partial_View : Node_Id := Empty) return Boolean |
| is |
| Etyp : Entity_Id := Typ; |
| |
| function Has_Specified_Stream_Attribute |
| (Typ : Entity_Id; |
| Nam : TSS_Name_Type) return Boolean; |
| -- True iff there is a visible attribute definition clause specifying |
| -- attribute Nam for Typ. |
| |
| ------------------------------------ |
| -- Has_Specified_Stream_Attribute -- |
| ------------------------------------ |
| |
| function Has_Specified_Stream_Attribute |
| (Typ : Entity_Id; |
| Nam : TSS_Name_Type) return Boolean |
| is |
| begin |
| return False |
| or else |
| (Nam = TSS_Stream_Input |
| and then Has_Specified_Stream_Input (Typ)) |
| or else |
| (Nam = TSS_Stream_Output |
| and then Has_Specified_Stream_Output (Typ)) |
| or else |
| (Nam = TSS_Stream_Read |
| and then Has_Specified_Stream_Read (Typ)) |
| or else |
| (Nam = TSS_Stream_Write |
| and then Has_Specified_Stream_Write (Typ)); |
| end Has_Specified_Stream_Attribute; |
| |
| -- Start of processing for Stream_Attribute_Available |
| |
| begin |
| -- We need some comments in this body ??? |
| |
| if Has_Specified_Stream_Attribute (Typ, Nam) then |
| return True; |
| end if; |
| |
| if Is_Class_Wide_Type (Typ) then |
| return not Is_Limited_Type (Typ) |
| or else Stream_Attribute_Available (Etype (Typ), Nam); |
| end if; |
| |
| if Nam = TSS_Stream_Input |
| and then Is_Abstract (Typ) |
| and then not Is_Class_Wide_Type (Typ) |
| then |
| return False; |
| end if; |
| |
| if not (Is_Limited_Type (Typ) |
| or else (Present (Partial_View) |
| and then Is_Limited_Type (Partial_View))) |
| then |
| return True; |
| end if; |
| |
| -- In Ada 2005, Input can invoke Read, and Output can invoke Write |
| |
| if Nam = TSS_Stream_Input |
| and then Ada_Version >= Ada_05 |
| and then Stream_Attribute_Available (Etyp, TSS_Stream_Read) |
| then |
| return True; |
| |
| elsif Nam = TSS_Stream_Output |
| and then Ada_Version >= Ada_05 |
| and then Stream_Attribute_Available (Etyp, TSS_Stream_Write) |
| then |
| return True; |
| end if; |
| |
| -- Case of Read and Write: check for attribute definition clause that |
| -- applies to an ancestor type. |
| |
| while Etype (Etyp) /= Etyp loop |
| Etyp := Etype (Etyp); |
| |
| if Has_Specified_Stream_Attribute (Etyp, Nam) then |
| return True; |
| end if; |
| end loop; |
| |
| if Ada_Version < Ada_05 then |
| |
| -- In Ada 95 mode, also consider a non-visible definition |
| |
| declare |
| Btyp : constant Entity_Id := Implementation_Base_Type (Typ); |
| begin |
| return Btyp /= Typ |
| and then Stream_Attribute_Available |
| (Btyp, Nam, Partial_View => Typ); |
| end; |
| end if; |
| |
| return False; |
| end Stream_Attribute_Available; |
| |
| end Sem_Attr; |