| //===-- DWARFExpression.h ---------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef liblldb_DWARFExpression_h_ |
| #define liblldb_DWARFExpression_h_ |
| |
| #include "lldb/lldb-private.h" |
| #include "lldb/Core/ClangForward.h" |
| #include "lldb/Core/Address.h" |
| #include "lldb/Core/DataExtractor.h" |
| #include "lldb/Core/Error.h" |
| #include "lldb/Core/Scalar.h" |
| |
| namespace lldb_private { |
| |
| class ClangExpressionVariable; |
| class ClangExpressionVariableList; |
| |
| class ClangExpressionDeclMap; |
| |
| //---------------------------------------------------------------------- |
| /// @class DWARFExpression DWARFExpression.h "lldb/Expression/DWARFExpression.h" |
| /// @brief Encapsulates a DWARF location expression and interprets it. |
| /// |
| /// DWARF location expressions are used in two ways by LLDB. The first |
| /// use is to find entities specified in the debug information, since |
| /// their locations are specified in precisely this language. The second |
| /// is to interpret expressions without having to run the target in cases |
| /// where the overhead from copying JIT-compiled code into the target is |
| /// too high or where the target cannot be run. This class encapsulates |
| /// a single DWARF location expression or a location list and interprets |
| /// it. |
| //---------------------------------------------------------------------- |
| class DWARFExpression |
| { |
| public: |
| //------------------------------------------------------------------ |
| /// Constructor |
| //------------------------------------------------------------------ |
| DWARFExpression(); |
| |
| //------------------------------------------------------------------ |
| /// Constructor |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read the DWARF location expression's |
| /// bytecode. |
| /// |
| /// @param[in] data_offset |
| /// The offset of the location expression in the extractor. |
| /// |
| /// @param[in] data_length |
| /// The byte length of the location expression. |
| //------------------------------------------------------------------ |
| DWARFExpression(lldb::ModuleSP module, |
| const DataExtractor& data, |
| lldb::offset_t data_offset, |
| lldb::offset_t data_length); |
| |
| //------------------------------------------------------------------ |
| /// Copy constructor |
| //------------------------------------------------------------------ |
| DWARFExpression(const DWARFExpression& rhs); |
| |
| //------------------------------------------------------------------ |
| /// Destructor |
| //------------------------------------------------------------------ |
| virtual |
| ~DWARFExpression(); |
| |
| //------------------------------------------------------------------ |
| /// Print the description of the expression to a stream |
| /// |
| /// @param[in] s |
| /// The stream to print to. |
| /// |
| /// @param[in] level |
| /// The level of verbosity to use. |
| /// |
| /// @param[in] location_list_base_addr |
| /// If this is a location list based expression, this is the |
| /// address of the object that owns it. NOTE: this value is |
| /// different from the DWARF version of the location list base |
| /// address which is compile unit relative. This base address |
| /// is the address of the object that owns the location list. |
| /// |
| /// @param[in] abi |
| /// An optional ABI plug-in that can be used to resolve register |
| /// names. |
| //------------------------------------------------------------------ |
| void |
| GetDescription (Stream *s, |
| lldb::DescriptionLevel level, |
| lldb::addr_t location_list_base_addr, |
| ABI *abi) const; |
| |
| //------------------------------------------------------------------ |
| /// Return true if the location expression contains data |
| //------------------------------------------------------------------ |
| bool |
| IsValid() const; |
| |
| //------------------------------------------------------------------ |
| /// Return true if a location list was provided |
| //------------------------------------------------------------------ |
| bool |
| IsLocationList() const; |
| |
| //------------------------------------------------------------------ |
| /// Search for a load address in the location list |
| /// |
| /// @param[in] process |
| /// The process to use when resolving the load address |
| /// |
| /// @param[in] addr |
| /// The address to resolve |
| /// |
| /// @return |
| /// True if IsLocationList() is true and the address was found; |
| /// false otherwise. |
| //------------------------------------------------------------------ |
| // bool |
| // LocationListContainsLoadAddress (Process* process, const Address &addr) const; |
| // |
| bool |
| LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const; |
| |
| //------------------------------------------------------------------ |
| /// If a location is not a location list, return true if the location |
| /// contains a DW_OP_addr () opcode in the stream that matches \a |
| /// file_addr. If file_addr is LLDB_INVALID_ADDRESS, the this |
| /// function will return true if the variable there is any DW_OP_addr |
| /// in a location that (yet still is NOT a location list). This helps |
| /// us detect if a variable is a global or static variable since |
| /// there is no other indication from DWARF debug info. |
| /// |
| /// @param[in] op_addr_idx |
| /// The DW_OP_addr index to retrieve in case there is more than |
| /// one DW_OP_addr opcode in the location byte stream. |
| /// |
| /// @param[out] error |
| /// If the location stream contains unknown DW_OP opcodes or the |
| /// data is missing, \a error will be set to \b true. |
| /// |
| /// @return |
| /// LLDB_INVALID_ADDRESS if the location doesn't contain a |
| /// DW_OP_addr for \a op_addr_idx, otherwise a valid file address |
| //------------------------------------------------------------------ |
| lldb::addr_t |
| GetLocation_DW_OP_addr (uint32_t op_addr_idx, bool &error) const; |
| |
| bool |
| Update_DW_OP_addr (lldb::addr_t file_addr); |
| |
| //------------------------------------------------------------------ |
| /// Make the expression parser read its location information from a |
| /// given data source. Does not change the offset and length |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read the DWARF location expression's |
| /// bytecode. |
| //------------------------------------------------------------------ |
| void |
| SetOpcodeData(const DataExtractor& data); |
| |
| //------------------------------------------------------------------ |
| /// Make the expression parser read its location information from a |
| /// given data source |
| /// |
| /// @param[in] module_sp |
| /// The module that defines the DWARF expression. |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read the DWARF location expression's |
| /// bytecode. |
| /// |
| /// @param[in] data_offset |
| /// The offset of the location expression in the extractor. |
| /// |
| /// @param[in] data_length |
| /// The byte length of the location expression. |
| //------------------------------------------------------------------ |
| void |
| SetOpcodeData(lldb::ModuleSP module_sp, const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length); |
| |
| //------------------------------------------------------------------ |
| /// Copy the DWARF location expression into a local buffer. |
| /// |
| /// It is a good idea to copy the data so we don't keep the entire |
| /// object file worth of data around just for a few bytes of location |
| /// expression. LLDB typically will mmap the entire contents of debug |
| /// information files, and if we use SetOpcodeData, it will get a |
| /// shared reference to all of this data for the and cause the object |
| /// file to have to stay around. Even worse, a very very large ".a" |
| /// that contains one or more .o files could end up being referenced. |
| /// Location lists are typically small so even though we are copying |
| /// the data, it shouldn't amount to that much for the variables we |
| /// end up parsing. |
| /// |
| /// @param[in] module_sp |
| /// The module that defines the DWARF expression. |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read and copy the DWARF |
| /// location expression's bytecode. |
| /// |
| /// @param[in] data_offset |
| /// The offset of the location expression in the extractor. |
| /// |
| /// @param[in] data_length |
| /// The byte length of the location expression. |
| //------------------------------------------------------------------ |
| void |
| CopyOpcodeData (lldb::ModuleSP module_sp, |
| const DataExtractor& data, |
| lldb::offset_t data_offset, |
| lldb::offset_t data_length); |
| |
| |
| //------------------------------------------------------------------ |
| /// Tells the expression that it refers to a location list. |
| /// |
| /// @param[in] slide |
| /// This value should be a slide that is applied to any values |
| /// in the location list data so the values become zero based |
| /// offsets into the object that owns the location list. We need |
| /// to make location lists relative to the objects that own them |
| /// so we can relink addresses on the fly. |
| //------------------------------------------------------------------ |
| void |
| SetLocationListSlide (lldb::addr_t slide); |
| |
| //------------------------------------------------------------------ |
| /// Return the call-frame-info style register kind |
| //------------------------------------------------------------------ |
| int |
| GetRegisterKind (); |
| |
| //------------------------------------------------------------------ |
| /// Set the call-frame-info style register kind |
| /// |
| /// @param[in] reg_kind |
| /// The register kind. |
| //------------------------------------------------------------------ |
| void |
| SetRegisterKind (lldb::RegisterKind reg_kind); |
| |
| //------------------------------------------------------------------ |
| /// Wrapper for the static evaluate function that accepts an |
| /// ExecutionContextScope instead of an ExecutionContext and uses |
| /// member variables to populate many operands |
| //------------------------------------------------------------------ |
| bool |
| Evaluate (ExecutionContextScope *exe_scope, |
| ClangExpressionVariableList *expr_locals, |
| ClangExpressionDeclMap *decl_map, |
| lldb::addr_t loclist_base_load_addr, |
| const Value* initial_value_ptr, |
| Value& result, |
| Error *error_ptr) const; |
| |
| //------------------------------------------------------------------ |
| /// Wrapper for the static evaluate function that uses member |
| /// variables to populate many operands |
| //------------------------------------------------------------------ |
| bool |
| Evaluate (ExecutionContext *exe_ctx, |
| ClangExpressionVariableList *expr_locals, |
| ClangExpressionDeclMap *decl_map, |
| RegisterContext *reg_ctx, |
| lldb::addr_t loclist_base_load_addr, |
| const Value* initial_value_ptr, |
| Value& result, |
| Error *error_ptr) const; |
| |
| //------------------------------------------------------------------ |
| /// Evaluate a DWARF location expression in a particular context |
| /// |
| /// @param[in] exe_ctx |
| /// The execution context in which to evaluate the location |
| /// expression. The location expression may access the target's |
| /// memory, especially if it comes from the expression parser. |
| /// |
| /// @param[in] opcode_ctx |
| /// The module which defined the expression. |
| /// |
| /// @param[in] opcodes |
| /// This is a static method so the opcodes need to be provided |
| /// explicitly. |
| /// |
| /// @param[in] expr_locals |
| /// If the location expression was produced by the expression parser, |
| /// the list of local variables referenced by the DWARF expression. |
| /// This list should already have been populated during parsing; |
| /// the DWARF expression refers to variables by index. Can be NULL if |
| /// the location expression uses no locals. |
| /// |
| /// @param[in] decl_map |
| /// If the location expression was produced by the expression parser, |
| /// the list of external variables referenced by the location |
| /// expression. Can be NULL if the location expression uses no |
| /// external variables. |
| /// |
| /// @param[in] reg_ctx |
| /// An optional parameter which provides a RegisterContext for use |
| /// when evaluating the expression (i.e. for fetching register values). |
| /// Normally this will come from the ExecutionContext's StackFrame but |
| /// in the case where an expression needs to be evaluated while building |
| /// the stack frame list, this short-cut is available. |
| /// |
| /// @param[in] offset |
| /// The offset of the location expression in the data extractor. |
| /// |
| /// @param[in] length |
| /// The length in bytes of the location expression. |
| /// |
| /// @param[in] reg_set |
| /// The call-frame-info style register kind. |
| /// |
| /// @param[in] initial_value_ptr |
| /// A value to put on top of the interpreter stack before evaluating |
| /// the expression, if the expression is parametrized. Can be NULL. |
| /// |
| /// @param[in] result |
| /// A value into which the result of evaluating the expression is |
| /// to be placed. |
| /// |
| /// @param[in] error_ptr |
| /// If non-NULL, used to report errors in expression evaluation. |
| /// |
| /// @return |
| /// True on success; false otherwise. If error_ptr is non-NULL, |
| /// details of the failure are provided through it. |
| //------------------------------------------------------------------ |
| static bool |
| Evaluate (ExecutionContext *exe_ctx, |
| ClangExpressionVariableList *expr_locals, |
| ClangExpressionDeclMap *decl_map, |
| RegisterContext *reg_ctx, |
| lldb::ModuleSP opcode_ctx, |
| const DataExtractor& opcodes, |
| const lldb::offset_t offset, |
| const lldb::offset_t length, |
| const lldb::RegisterKind reg_set, |
| const Value* initial_value_ptr, |
| Value& result, |
| Error *error_ptr); |
| |
| //------------------------------------------------------------------ |
| /// Loads a ClangExpressionVariableList into the object |
| /// |
| /// @param[in] locals |
| /// If non-NULL, the list of locals used by this expression. |
| /// See Evaluate(). |
| //------------------------------------------------------------------ |
| void |
| SetExpressionLocalVariableList (ClangExpressionVariableList *locals); |
| |
| //------------------------------------------------------------------ |
| /// Loads a ClangExpressionDeclMap into the object |
| /// |
| /// @param[in] locals |
| /// If non-NULL, the list of external variables used by this |
| /// expression. See Evaluate(). |
| //------------------------------------------------------------------ |
| void |
| SetExpressionDeclMap (ClangExpressionDeclMap *decl_map); |
| |
| bool |
| GetExpressionData (DataExtractor &data) const |
| { |
| data = m_data; |
| return data.GetByteSize() > 0; |
| } |
| |
| bool |
| DumpLocationForAddress (Stream *s, |
| lldb::DescriptionLevel level, |
| lldb::addr_t loclist_base_load_addr, |
| lldb::addr_t address, |
| ABI *abi); |
| |
| protected: |
| //------------------------------------------------------------------ |
| /// Pretty-prints the location expression to a stream |
| /// |
| /// @param[in] stream |
| /// The stream to use for pretty-printing. |
| /// |
| /// @param[in] offset |
| /// The offset into the data buffer of the opcodes to be printed. |
| /// |
| /// @param[in] length |
| /// The length in bytes of the opcodes to be printed. |
| /// |
| /// @param[in] level |
| /// The level of detail to use in pretty-printing. |
| /// |
| /// @param[in] abi |
| /// An optional ABI plug-in that can be used to resolve register |
| /// names. |
| //------------------------------------------------------------------ |
| void |
| DumpLocation(Stream *s, |
| lldb::offset_t offset, |
| lldb::offset_t length, |
| lldb::DescriptionLevel level, |
| ABI *abi) const; |
| |
| bool |
| GetLocation (lldb::addr_t base_addr, |
| lldb::addr_t pc, |
| lldb::offset_t &offset, |
| lldb::offset_t &len); |
| |
| //------------------------------------------------------------------ |
| /// Classes that inherit from DWARFExpression can see and modify these |
| //------------------------------------------------------------------ |
| |
| lldb::ModuleWP m_module_wp; ///< Module which defined this expression. |
| DataExtractor m_data; ///< A data extractor capable of reading opcode bytes |
| lldb::RegisterKind m_reg_kind; ///< One of the defines that starts with LLDB_REGKIND_ |
| lldb::addr_t m_loclist_slide; ///< A value used to slide the location list offsets so that |
| ///< they are relative to the object that owns the location list |
| ///< (the function for frame base and variable location lists) |
| |
| }; |
| |
| } // namespace lldb_private |
| |
| #endif // liblldb_DWARFExpression_h_ |
