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/* APPLE LOCAL begin LLVM (ENTIRE FILE!) */
/* Tree type to LLVM type converter
Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by Chris Lattner (sabre@nondot.org)
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT 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
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
//===----------------------------------------------------------------------===//
// This is the code that converts GCC tree types into LLVM types.
//===----------------------------------------------------------------------===//
#include "llvm-internal.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/TypeSymbolTable.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringExtras.h"
#include <iostream>
#include <map>
extern "C" {
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
}
#include "llvm-abi.h"
//===----------------------------------------------------------------------===//
// Matching LLVM types with GCC trees
//===----------------------------------------------------------------------===//
//
// LTypes is a vector of LLVM types. GCC tree nodes keep track of LLVM types
// using this vector's index. It is easier to save and restore the index than
// the LLVM type pointer while usig PCH. STL vector does not provide fast
// searching mechanism which is required to remove LLVM Type entry when type is
// refined and replaced by another LLVM Type. This is achieved by maintaining
// a map.
// Collection of LLVM Types
static std::vector<const Type *> LTypes;
typedef DenseMap<const Type *, unsigned> LTypesMapTy;
static LTypesMapTy LTypesMap;
// GET_TYPE_LLVM/SET_TYPE_LLVM - Associate an LLVM type with each TREE type.
// These are lazily computed by ConvertType.
#define SET_TYPE_SYMTAB_LLVM(NODE, index) \
(TYPE_CHECK (NODE)->type.symtab.llvm = index)
// Note down LLVM type for GCC tree node.
static const Type * llvm_set_type(tree Tr, const Type *Ty) {
// For x86 long double, llvm records the size of the data (80) while
// gcc's TYPE_SIZE including alignment padding. getABITypeSizeInBits
// is used to compensate for this.
assert((!TYPE_SIZE(Tr) || !Ty->isSized() || !isInt64(TYPE_SIZE(Tr), true) ||
getInt64(TYPE_SIZE(Tr), true) ==
getTargetData().getABITypeSizeInBits(Ty))
&& "LLVM type size doesn't match GCC type size!");
unsigned &TypeSlot = LTypesMap[Ty];
if (TypeSlot) {
// Already in map.
SET_TYPE_SYMTAB_LLVM(Tr, TypeSlot);
return Ty;
}
unsigned Index = LTypes.size() + 1;
LTypes.push_back(Ty);
SET_TYPE_SYMTAB_LLVM(Tr, Index);
LTypesMap[Ty] = Index;
return Ty;
}
#define SET_TYPE_LLVM(NODE, TYPE) (const Type *)llvm_set_type(NODE, TYPE)
// Get LLVM Type for the GCC tree node based on LTypes vector index.
// When GCC tree node is initialized, it has 0 as the index value. This is
// why all recorded indexes are offset by 1.
extern "C" const Type *llvm_get_type(unsigned Index) {
if (Index == 0)
return NULL;
assert ((Index - 1) < LTypes.size() && "Invalid LLVM Type index");
return LTypes[Index - 1];
}
#define GET_TYPE_LLVM(NODE) \
(const Type *)llvm_get_type( TYPE_CHECK (NODE)->type.symtab.llvm)
// Erase type from LTypes vector
static void llvmEraseLType(const Type *Ty) {
LTypesMapTy::iterator I = LTypesMap.find(Ty);
if (I != LTypesMap.end()) {
// It is OK to clear this entry instead of removing this entry
// to avoid re-indexing of other entries.
LTypes[ LTypesMap[Ty] - 1] = NULL;
LTypesMap.erase(I);
}
}
// Read LLVM Types string table
void readLLVMTypesStringTable() {
GlobalValue *V = TheModule->getNamedGlobal("llvm.pch.types");
if (!V)
return;
// Value *GV = TheModule->getValueSymbolTable().lookup("llvm.pch.types");
GlobalVariable *GV = cast<GlobalVariable>(V);
ConstantStruct *LTypesNames = cast<ConstantStruct>(GV->getOperand(0));
for (unsigned i = 0; i < LTypesNames->getNumOperands(); ++i) {
const Type *Ty = NULL;
if (ConstantArray *CA =
dyn_cast<ConstantArray>(LTypesNames->getOperand(i))) {
std::string Str = CA->getAsString();
Ty = TheModule->getTypeByName(Str);
assert (Ty != NULL && "Invalid Type in LTypes string table");
}
// If V is not a string then it is empty. Insert NULL to represent
// empty entries.
LTypes.push_back(Ty);
}
// Now, llvm.pch.types value is not required so remove it from the symbol
// table.
GV->eraseFromParent();
}
// GCC tree's uses LTypes vector's index to reach LLVM types.
// Create a string table to hold these LLVM types' names. This string
// table will be used to recreate LTypes vector after loading PCH.
void writeLLVMTypesStringTable() {
if (LTypes.empty())
return;
std::vector<Constant *> LTypesNames;
std::map < const Type *, std::string > TypeNameMap;
// Collect Type Names in advance.
const TypeSymbolTable &ST = TheModule->getTypeSymbolTable();
TypeSymbolTable::const_iterator TI = ST.begin();
for (; TI != ST.end(); ++TI) {
TypeNameMap[TI->second] = TI->first;
}
// Populate LTypesNames vector.
for (std::vector<const Type *>::iterator I = LTypes.begin(),
E = LTypes.end(); I != E; ++I) {
const Type *Ty = *I;
// Give names to nameless types.
if (Ty && TypeNameMap[Ty].empty()) {
std::string NewName =
TheModule->getTypeSymbolTable().getUniqueName("llvm.fe.ty");
TheModule->addTypeName(NewName, Ty);
TypeNameMap[*I] = NewName;
}
const std::string &TypeName = TypeNameMap[*I];
LTypesNames.push_back(ConstantArray::get(TypeName, false));
}
// Create string table.
Constant *LTypesNameTable = ConstantStruct::get(LTypesNames, false);
// Create variable to hold this string table.
GlobalVariable *GV = new GlobalVariable(LTypesNameTable->getType(), true,
GlobalValue::ExternalLinkage,
LTypesNameTable,
"llvm.pch.types", TheModule);
}
//===----------------------------------------------------------------------===//
// Recursive Type Handling Code and Data
//===----------------------------------------------------------------------===//
// Recursive types are a major pain to handle for a couple of reasons. Because
// of this, when we start parsing a struct or a union, we globally change how
// POINTER_TYPE and REFERENCE_TYPE are handled. In particular, instead of
// actually recursing and computing the type they point to, they will return an
// opaque*, and remember that they did this in PointersToReresolve.
/// GetFunctionType - This is just a helper like FunctionType::get but that
/// takes PATypeHolders.
static FunctionType *GetFunctionType(const PATypeHolder &Res,
std::vector<PATypeHolder> &ArgTys,
bool isVarArg) {
std::vector<const Type*> ArgTysP;
ArgTysP.reserve(ArgTys.size());
for (unsigned i = 0, e = ArgTys.size(); i != e; ++i)
ArgTysP.push_back(ArgTys[i]);
return FunctionType::get(Res, ArgTysP, isVarArg);
}
//===----------------------------------------------------------------------===//
// Type Conversion Utilities
//===----------------------------------------------------------------------===//
// isPassedByInvisibleReference - Return true if an argument of the specified
// type should be passed in by invisible reference.
//
bool isPassedByInvisibleReference(tree Type) {
// FIXME: Search for TREE_ADDRESSABLE in calls.c, and see if there are other
// cases that make arguments automatically passed in by reference.
return TREE_ADDRESSABLE(Type) || TYPE_SIZE(Type) == 0 ||
TREE_CODE(TYPE_SIZE(Type)) != INTEGER_CST;
}
/// GetTypeName - Return a fully qualified (with namespace prefixes) name for
/// the specified type.
static std::string GetTypeName(const char *Prefix, tree type) {
const char *Name = "anon";
if (TYPE_NAME(type))
if (TREE_CODE(TYPE_NAME(type)) == IDENTIFIER_NODE)
Name = IDENTIFIER_POINTER(TYPE_NAME(type));
else
Name = IDENTIFIER_POINTER(DECL_NAME(TYPE_NAME(type)));
std::string ContextStr;
tree Context = TYPE_CONTEXT(type);
while (Context) {
switch (TREE_CODE(Context)) {
case TRANSLATION_UNIT_DECL: Context = 0; break; // Done.
case RECORD_TYPE:
case NAMESPACE_DECL:
if (TREE_CODE(Context) == RECORD_TYPE) {
if (TYPE_NAME(Context)) {
std::string NameFrag;
if (TREE_CODE(TYPE_NAME(Context)) == IDENTIFIER_NODE) {
NameFrag = IDENTIFIER_POINTER(TYPE_NAME(Context));
} else {
NameFrag = IDENTIFIER_POINTER(DECL_NAME(TYPE_NAME(Context)));
}
ContextStr = NameFrag + "::" + ContextStr;
Context = TYPE_CONTEXT(Context);
break;
}
// Anonymous record, fall through.
} else if (DECL_NAME(Context)
/*&& DECL_NAME(Context) != anonymous_namespace_name*/){
assert(TREE_CODE(DECL_NAME(Context)) == IDENTIFIER_NODE);
std::string NamespaceName = IDENTIFIER_POINTER(DECL_NAME(Context));
ContextStr = NamespaceName + "::" + ContextStr;
Context = DECL_CONTEXT(Context);
break;
}
// FALL THROUGH for anonymous namespaces and records!
default: {
// If this is a structure type defined inside of a function or other block
// scope, make sure to make the type name unique by putting a unique ID
// in it.
static unsigned UniqueID = 0;
ContextStr = "." + utostr(UniqueID++);
Context = 0; // Stop looking at context
break;
}
}
}
return Prefix + ContextStr + Name;
}
/// isSequentialCompatible - Return true if the specified gcc array or pointer
/// type and the corresponding LLVM SequentialType lay out their components
/// identically in memory.
bool isSequentialCompatible(tree_node *type) {
assert((TREE_CODE (type) == ARRAY_TYPE ||
TREE_CODE (type) == POINTER_TYPE ||
TREE_CODE (type) == REFERENCE_TYPE) && "not a sequential type!");
// This relies on gcc types with constant size mapping to LLVM types with the
// same size.
return !VOID_TYPE_P(TREE_TYPE(type)) && isInt64(TYPE_SIZE(TREE_TYPE(type)), true);
}
/// isArrayCompatible - Return true if the specified gcc array or pointer type
/// corresponds to an LLVM array type.
bool isArrayCompatible(tree_node *type) {
assert((TREE_CODE (type) == ARRAY_TYPE ||
TREE_CODE (type) == POINTER_TYPE ||
TREE_CODE (type) == REFERENCE_TYPE) && "not a sequential type!");
return
(TREE_CODE (type) == ARRAY_TYPE) && (
// Arrays with no size are fine as long as their components are layed out
// the same way in memory by LLVM. For example "int X[]" -> "[0 x int]".
(!TYPE_SIZE(type) && isSequentialCompatible(type)) ||
// Arrays with constant size map to LLVM arrays. If the array has zero
// size then there can be two exotic cases: (1) the array might have zero
// length and a component type of variable size; or (2) the array could
// have variable length and a component type with zero size. In both
// cases we convert to a zero length LLVM array.
(TYPE_SIZE(type) && isInt64(TYPE_SIZE(type), true))
);
}
/// arrayLength - Return a tree expressing the number of elements in an array
/// of the specified type, or NULL if the type does not specify the length.
tree_node *arrayLength(tree_node *type) {
tree Domain = TYPE_DOMAIN(type);
if (!Domain || !TYPE_MAX_VALUE(Domain))
return NULL;
tree length = fold_convert(sizetype, TYPE_MAX_VALUE(Domain));
if (TYPE_MIN_VALUE(Domain))
length = size_binop (MINUS_EXPR, length,
fold_convert(sizetype, TYPE_MIN_VALUE(Domain)));
return size_binop (PLUS_EXPR, length, size_one_node);
}
//===----------------------------------------------------------------------===//
// Abstract Type Refinement Helpers
//===----------------------------------------------------------------------===//
//
// This code is built to make sure that the TYPE_LLVM field on tree types are
// updated when LLVM types are refined. This prevents dangling pointers from
// occuring due to type coallescing.
//
namespace {
class TypeRefinementDatabase : public AbstractTypeUser {
virtual void refineAbstractType(const DerivedType *OldTy,
const Type *NewTy);
virtual void typeBecameConcrete(const DerivedType *AbsTy);
// TypeUsers - For each abstract LLVM type, we keep track of all of the GCC
// types that point to it.
std::map<const Type*, std::vector<tree> > TypeUsers;
public:
/// setType - call SET_TYPE_LLVM(type, Ty), associating the type with the
/// specified tree type. In addition, if the LLVM type is an abstract type,
/// we add it to our data structure to track it.
inline const Type *setType(tree type, const Type *Ty) {
if (GET_TYPE_LLVM(type))
RemoveTypeFromTable(type);
if (Ty->isAbstract()) {
std::vector<tree> &Users = TypeUsers[Ty];
if (Users.empty()) Ty->addAbstractTypeUser(this);
Users.push_back(type);
}
return SET_TYPE_LLVM(type, Ty);
}
void RemoveTypeFromTable(tree type);
void dump() const;
};
/// TypeDB - The main global type database.
TypeRefinementDatabase TypeDB;
}
/// RemoveTypeFromTable - We're about to change the LLVM type of 'type'
///
void TypeRefinementDatabase::RemoveTypeFromTable(tree type) {
const Type *Ty = GET_TYPE_LLVM(type);
if (!Ty->isAbstract()) return;
std::map<const Type*, std::vector<tree> >::iterator I = TypeUsers.find(Ty);
assert(I != TypeUsers.end() && "Using an abstract type but not in table?");
bool FoundIt = false;
for (unsigned i = 0, e = I->second.size(); i != e; ++i)
if (I->second[i] == type) {
FoundIt = true;
std::swap(I->second[i], I->second.back());
I->second.pop_back();
break;
}
assert(FoundIt && "Using an abstract type but not in table?");
// If the type plane is now empty, nuke it.
if (I->second.empty()) {
TypeUsers.erase(I);
Ty->removeAbstractTypeUser(this);
}
}
/// refineAbstractType - The callback method invoked when an abstract type is
/// resolved to another type. An object must override this method to update
/// its internal state to reference NewType instead of OldType.
///
void TypeRefinementDatabase::refineAbstractType(const DerivedType *OldTy,
const Type *NewTy) {
if (OldTy == NewTy && OldTy->isAbstract()) return; // Nothing to do.
std::map<const Type*, std::vector<tree> >::iterator I = TypeUsers.find(OldTy);
assert(I != TypeUsers.end() && "Using an abstract type but not in table?");
if (!NewTy->isAbstract()) {
// If the type became concrete, update everything pointing to it, and remove
// all of our entries from the map.
if (OldTy != NewTy)
for (unsigned i = 0, e = I->second.size(); i != e; ++i)
SET_TYPE_LLVM(I->second[i], NewTy);
} else {
// Otherwise, it was refined to another instance of an abstract type. Move
// everything over and stop monitoring OldTy.
std::vector<tree> &NewSlot = TypeUsers[NewTy];
if (NewSlot.empty()) NewTy->addAbstractTypeUser(this);
for (unsigned i = 0, e = I->second.size(); i != e; ++i) {
NewSlot.push_back(I->second[i]);
SET_TYPE_LLVM(I->second[i], NewTy);
}
}
llvmEraseLType(OldTy);
TypeUsers.erase(I);
// Next, remove OldTy's entry in the TargetData object if it has one.
if (const StructType *STy = dyn_cast<StructType>(OldTy))
getTargetData().InvalidateStructLayoutInfo(STy);
OldTy->removeAbstractTypeUser(this);
}
/// The other case which AbstractTypeUsers must be aware of is when a type
/// makes the transition from being abstract (where it has clients on it's
/// AbstractTypeUsers list) to concrete (where it does not). This method
/// notifies ATU's when this occurs for a type.
///
void TypeRefinementDatabase::typeBecameConcrete(const DerivedType *AbsTy) {
assert(TypeUsers.count(AbsTy) && "Not using this type!");
// Remove the type from our collection of tracked types.
TypeUsers.erase(AbsTy);
AbsTy->removeAbstractTypeUser(this);
}
void TypeRefinementDatabase::dump() const {
std::cerr << "TypeRefinementDatabase\n";
}
//===----------------------------------------------------------------------===//
// Helper Routines
//===----------------------------------------------------------------------===//
/// getFieldOffsetInBits - Return the offset (in bits) of a FIELD_DECL in a
/// structure.
static unsigned getFieldOffsetInBits(tree Field) {
assert(DECL_FIELD_BIT_OFFSET(Field) != 0 && DECL_FIELD_OFFSET(Field) != 0);
unsigned Result = TREE_INT_CST_LOW(DECL_FIELD_BIT_OFFSET(Field));
if (TREE_CODE(DECL_FIELD_OFFSET(Field)) == INTEGER_CST)
Result += TREE_INT_CST_LOW(DECL_FIELD_OFFSET(Field))*8;
return Result;
}
/// FindLLVMTypePadding - If the specified struct has any inter-element padding,
/// add it to the Padding array.
static void FindLLVMTypePadding(const Type *Ty, unsigned BitOffset,
SmallVector<std::pair<unsigned,unsigned>, 16> &Padding) {
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
const TargetData &TD = getTargetData();
const StructLayout *SL = TD.getStructLayout(STy);
unsigned PrevFieldBitOffset = 0;
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
unsigned FieldBitOffset = SL->getElementOffset(i)*8;
// Get padding of sub-elements.
FindLLVMTypePadding(STy->getElementType(i),
BitOffset+FieldBitOffset, Padding);
// Check to see if there is any padding between this element and the
// previous one.
if (i) {
unsigned PrevFieldEnd =
PrevFieldBitOffset+TD.getTypeSizeInBits(STy->getElementType(i-1));
if (PrevFieldEnd < FieldBitOffset)
Padding.push_back(std::make_pair(PrevFieldEnd+BitOffset,
FieldBitOffset-PrevFieldEnd));
}
PrevFieldBitOffset = FieldBitOffset;
}
// Check for tail padding.
if (unsigned EltCount = STy->getNumElements()) {
unsigned PrevFieldEnd = PrevFieldBitOffset +
TD.getTypeSizeInBits(STy->getElementType(EltCount-1));
if (PrevFieldEnd < SL->getSizeInBytes()*8)
Padding.push_back(std::make_pair(PrevFieldEnd,
SL->getSizeInBytes()*8-PrevFieldEnd));
}
} else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
unsigned EltSize = getTargetData().getTypeSizeInBits(ATy->getElementType());
for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
FindLLVMTypePadding(ATy->getElementType(), BitOffset+i*EltSize, Padding);
}
// primitive and vector types have no padding.
}
/// GCCTypeOverlapsWithPadding - Return true if the specified gcc type overlaps
/// with the specified region of padding. This only needs to handle types with
/// a constant size.
static bool GCCTypeOverlapsWithPadding(tree type, int PadStartBits,
int PadSizeBits) {
assert(type != error_mark_node);
// LLVM doesn't care about variants such as const, volatile, or restrict.
type = TYPE_MAIN_VARIANT(type);
// If the type does not overlap, don't bother checking below.
if (!TYPE_SIZE(type))
// C-style variable length array? Be conservative.
return true;
if (!isInt64(TYPE_SIZE(type), true))
// Negative size (!) or huge - be conservative.
return true;
if (!getInt64(TYPE_SIZE(type), true) ||
PadStartBits >= (int64_t)getInt64(TYPE_SIZE(type), false) ||
PadStartBits+PadSizeBits <= 0)
return false;
switch (TREE_CODE(type)) {
default:
fprintf(stderr, "Unknown type to compare:\n");
debug_tree(type);
abort();
case VOID_TYPE:
case BOOLEAN_TYPE:
case ENUMERAL_TYPE:
case INTEGER_TYPE:
case REAL_TYPE:
case COMPLEX_TYPE:
case VECTOR_TYPE:
case POINTER_TYPE:
case REFERENCE_TYPE:
// These types have no holes.
return true;
case ARRAY_TYPE: {
unsigned EltSizeBits = TREE_INT_CST_LOW(TYPE_SIZE(TREE_TYPE(type)));
unsigned NumElts = getInt64(arrayLength(type), true);
unsigned OverlapElt = (unsigned)PadStartBits/EltSizeBits;
// Check each element for overlap. This is inelegant, but effective.
for (unsigned i = 0; i != NumElts; ++i)
if (GCCTypeOverlapsWithPadding(TREE_TYPE(type),
PadStartBits- i*EltSizeBits, PadSizeBits))
return true;
return false;
}
case UNION_TYPE: {
// If this is a union with the transparent_union attribute set, it is
// treated as if it were just the same as its first type.
if (TYPE_TRANSPARENT_UNION(type)) {
tree Field = TYPE_FIELDS(type);
assert(Field && "Transparent union must have some elements!");
while (TREE_CODE(Field) != FIELD_DECL) {
Field = TREE_CHAIN(Field);
assert(Field && "Transparent union must have some elements!");
}
return GCCTypeOverlapsWithPadding(TREE_TYPE(Field),
PadStartBits, PadSizeBits);
}
// See if any elements overlap.
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (TREE_CODE(Field) != FIELD_DECL) continue;
assert(getFieldOffsetInBits(Field) == 0 && "Union with non-zero offset?");
if (GCCTypeOverlapsWithPadding(TREE_TYPE(Field),
PadStartBits, PadSizeBits))
return true;
}
return false;
}
case RECORD_TYPE:
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (TREE_CODE(Field) != FIELD_DECL) continue;
if (TREE_CODE(DECL_FIELD_OFFSET(Field)) != INTEGER_CST)
return true;
unsigned FieldBitOffset = getFieldOffsetInBits(Field);
if (GCCTypeOverlapsWithPadding(TREE_TYPE(Field),
PadStartBits-FieldBitOffset, PadSizeBits))
return true;
}
return false;
}
}
bool TypeConverter::GCCTypeOverlapsWithLLVMTypePadding(tree type,
const Type *Ty) {
// Start by finding all of the padding in the LLVM Type.
SmallVector<std::pair<unsigned,unsigned>, 16> StructPadding;
FindLLVMTypePadding(Ty, 0, StructPadding);
for (unsigned i = 0, e = StructPadding.size(); i != e; ++i)
if (GCCTypeOverlapsWithPadding(type, StructPadding[i].first,
StructPadding[i].second))
return true;
return false;
}
//===----------------------------------------------------------------------===//
// Main Type Conversion Routines
//===----------------------------------------------------------------------===//
const Type *TypeConverter::ConvertType(tree orig_type) {
if (orig_type == error_mark_node) return Type::Int32Ty;
// LLVM doesn't care about variants such as const, volatile, or restrict.
tree type = TYPE_MAIN_VARIANT(orig_type);
switch (TREE_CODE(type)) {
default:
fprintf(stderr, "Unknown type to convert:\n");
debug_tree(type);
abort();
case VOID_TYPE: return SET_TYPE_LLVM(type, Type::VoidTy);
case RECORD_TYPE: return ConvertRECORD(type, orig_type);
case UNION_TYPE: return ConvertUNION(type, orig_type);
case BOOLEAN_TYPE: {
if (const Type *Ty = GET_TYPE_LLVM(type))
return Ty;
return SET_TYPE_LLVM(type,
IntegerType::get(TREE_INT_CST_LOW(TYPE_SIZE(type))));
}
case ENUMERAL_TYPE:
// Use of an enum that is implicitly declared?
if (TYPE_SIZE(orig_type) == 0) {
// If we already compiled this type, use the old type.
if (const Type *Ty = GET_TYPE_LLVM(orig_type))
return Ty;
const Type *Ty = OpaqueType::get();
TheModule->addTypeName(GetTypeName("enum.", orig_type), Ty);
return TypeDB.setType(orig_type, Ty);
}
// FALL THROUGH.
type = orig_type;
case INTEGER_TYPE:
if (const Type *Ty = GET_TYPE_LLVM(type)) return Ty;
// FIXME: eliminate this when 128-bit integer types in LLVM work.
switch (TREE_INT_CST_LOW(TYPE_SIZE(type))) {
case 1:
case 8:
case 16:
case 32:
case 64:
//case 128: Waiting for PR1462 etc.
break;
default:
static bool Warned = false;
if (!Warned)
fprintf(stderr, "WARNING: %d-bit integers not supported!\n",
(int)TREE_INT_CST_LOW(TYPE_SIZE(type)));
Warned = true;
return Type::Int64Ty;
}
return SET_TYPE_LLVM(type,
IntegerType::get(TREE_INT_CST_LOW(TYPE_SIZE(type))));
case REAL_TYPE:
if (const Type *Ty = GET_TYPE_LLVM(type)) return Ty;
switch (TYPE_PRECISION(type)) {
default:
fprintf(stderr, "Unknown FP type!\n");
debug_tree(type);
abort();
case 32: return SET_TYPE_LLVM(type, Type::FloatTy);
case 64: return SET_TYPE_LLVM(type, Type::DoubleTy);
case 80: return SET_TYPE_LLVM(type, Type::X86_FP80Ty);
case 128:
#ifdef TARGET_POWERPC
return SET_TYPE_LLVM(type, Type::PPC_FP128Ty);
#elif 0
// This is for IEEE double extended, e.g. Sparc
return SET_TYPE_LLVM(type, Type::FP128Ty);
#else
// 128-bit long doubles map onto { double, double }.
const Type *Ty = Type::DoubleTy;
Ty = StructType::get(std::vector<const Type*>(2, Ty), false);
return SET_TYPE_LLVM(type, Ty);
#endif
}
case COMPLEX_TYPE: {
if (const Type *Ty = GET_TYPE_LLVM(type)) return Ty;
const Type *Ty = ConvertType(TREE_TYPE(type));
assert(!Ty->isAbstract() && "should use TypeDB.setType()");
Ty = StructType::get(std::vector<const Type*>(2, Ty), false);
return SET_TYPE_LLVM(type, Ty);
}
case VECTOR_TYPE: {
if (const Type *Ty = GET_TYPE_LLVM(type)) return Ty;
const Type *Ty = ConvertType(TREE_TYPE(type));
assert(!Ty->isAbstract() && "should use TypeDB.setType()");
Ty = VectorType::get(Ty, TYPE_VECTOR_SUBPARTS(type));
return SET_TYPE_LLVM(type, Ty);
}
case POINTER_TYPE:
case REFERENCE_TYPE:
if (const PointerType *Ty = cast_or_null<PointerType>(GET_TYPE_LLVM(type))){
// We already converted this type. If this isn't a case where we have to
// reparse it, just return it.
if (PointersToReresolve.empty() || PointersToReresolve.back() != type ||
ConvertingStruct)
return Ty;
// Okay, we know that we're !ConvertingStruct and that type is on the end
// of the vector. Remove this entry from the PointersToReresolve list and
// get the pointee type. Note that this order is important in case the
// pointee type uses this pointer.
assert(isa<OpaqueType>(Ty->getElementType()) && "Not a deferred ref!");
// We are actively resolving this pointer. We want to pop this value from
// the stack, as we are no longer resolving it. However, we don't want to
// make it look like we are now resolving the previous pointer on the
// stack, so pop this value and push a null.
PointersToReresolve.back() = 0;
// Do not do any nested resolution. We know that there is a higher-level
// loop processing deferred pointers, let it handle anything new.
ConvertingStruct = true;
// Note that we know that Ty cannot be resolved or invalidated here.
const Type *Actual = ConvertType(TREE_TYPE(type));
assert(GET_TYPE_LLVM(type) == Ty && "Pointer invalidated!");
// Restore ConvertingStruct for the caller.
ConvertingStruct = false;
if (Actual->getTypeID() == Type::VoidTyID)
Actual = Type::Int8Ty; // void* -> sbyte*
// Update the type, potentially updating TYPE_LLVM(type).
const OpaqueType *OT = cast<OpaqueType>(Ty->getElementType());
const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(Actual);
return GET_TYPE_LLVM(type);
} else {
const Type *Ty;
// If we are converting a struct, and if we haven't converted the pointee
// type, add this pointer to PointersToReresolve and return an opaque*.
if (ConvertingStruct) {
// If the pointee type has not already been converted to LLVM, create
// a new opaque type and remember it in the database.
Ty = GET_TYPE_LLVM(TYPE_MAIN_VARIANT(TREE_TYPE(type)));
if (Ty == 0) {
PointersToReresolve.push_back(type);
return TypeDB.setType(type,
PointerType::getUnqual(OpaqueType::get()));
}
// A type has already been computed. However, this may be some sort of
// recursive struct. We don't want to call ConvertType on it, because
// this will try to resolve it, and not adding the type to the
// PointerToReresolve collection is just an optimization. Instead,
// we'll use the type returned by GET_TYPE_LLVM directly, even if this
// may be resolved further in the future.
} else {
// If we're not in a struct, just call ConvertType. If it has already
// been converted, this will return the precomputed value, otherwise
// this will compute and return the new type.
Ty = ConvertType(TREE_TYPE(type));
}
if (Ty->getTypeID() == Type::VoidTyID)
Ty = Type::Int8Ty; // void* -> sbyte*
return TypeDB.setType(type, PointerType::getUnqual(Ty));
}
case METHOD_TYPE:
case FUNCTION_TYPE: {
if (const Type *Ty = GET_TYPE_LLVM(type))
return Ty;
// No declaration to pass through, passing NULL.
unsigned CallingConv;
PAListPtr PAL;
return TypeDB.setType(type, ConvertFunctionType(type, NULL, NULL,
CallingConv, PAL));
}
case ARRAY_TYPE: {
if (const Type *Ty = GET_TYPE_LLVM(type))
return Ty;
if (isArrayCompatible(type)) {
uint64_t NumElements;
tree length = arrayLength(type);
if (!length) {
// We get here if we have something that is globally declared as an
// array with no dimension, this becomes just a zero size array of the
// element type so that: int X[] becomes '%X = external global [0x i32]'
//
// Note that this also affects new expressions, which return a pointer
// to an unsized array of elements.
NumElements = 0;
} else if (!isInt64(length, true)) {
// A variable length array where the element type has size zero. Turn
// it into a zero length array of the element type.
assert(integer_zerop(TYPE_SIZE(TREE_TYPE(type)))
&& "variable length array has constant size!");
NumElements = 0;
} else {
// Normal array.
NumElements = getInt64(length, true);
}
return TypeDB.setType(type, ArrayType::get(ConvertType(TREE_TYPE(type)),
NumElements));
}
// This handles cases like "int A[n]" which have a runtime constant
// number of elements, but is a compile-time variable. Since these are
// variable sized, we just represent them as the element themself.
return TypeDB.setType(type, ConvertType(TREE_TYPE(type)));
}
case OFFSET_TYPE:
// Handle OFFSET_TYPE specially. This is used for pointers to members,
// which are really just integer offsets. As such, return the appropriate
// integer directly.
switch (getTargetData().getPointerSize()) {
default: assert(0 && "Unknown pointer size!");
case 4: return Type::Int32Ty;
case 8: return Type::Int64Ty;
}
}
}
//===----------------------------------------------------------------------===//
// FUNCTION/METHOD_TYPE Conversion Routines
//===----------------------------------------------------------------------===//
namespace {
class FunctionTypeConversion : public DefaultABIClient {
PATypeHolder &RetTy;
std::vector<PATypeHolder> &ArgTypes;
unsigned &CallingConv;
bool isStructRet;
bool KNRPromotion;
public:
FunctionTypeConversion(PATypeHolder &retty, std::vector<PATypeHolder> &AT,
unsigned &CC, bool KNR)
: RetTy(retty), ArgTypes(AT), CallingConv(CC), KNRPromotion(KNR) {
CallingConv = CallingConv::C;
isStructRet = false;
}
bool isStructReturn() const { return isStructRet; }
/// HandleScalarResult - This callback is invoked if the function returns a
/// simple scalar result value.
void HandleScalarResult(const Type *RetTy) {
this->RetTy = RetTy;
}
/// HandleAggregateResultAsScalar - This callback is invoked if the function
/// returns an aggregate value by bit converting it to the specified scalar
/// type and returning that.
void HandleAggregateResultAsScalar(const Type *ScalarTy) {
RetTy = ScalarTy;
}
/// HandleAggregateShadowArgument - This callback is invoked if the function
/// returns an aggregate value by using a "shadow" first parameter. If
/// RetPtr is set to true, the pointer argument itself is returned from
/// the function.
void HandleAggregateShadowArgument(const PointerType *PtrArgTy,
bool RetPtr) {
// If this function returns a structure by value, it either returns void
// or the shadow argument, depending on the target.
this->RetTy = RetPtr ? PtrArgTy : Type::VoidTy;
// In any case, there is a dummy shadow argument though!
ArgTypes.push_back(PtrArgTy);
// Also, switch the to C Struct Return.
isStructRet = true;
}
void HandleScalarArgument(const llvm::Type *LLVMTy, tree type) {
if (KNRPromotion) {
if (LLVMTy == Type::FloatTy)
LLVMTy = Type::DoubleTy;
else if (LLVMTy == Type::Int16Ty || LLVMTy == Type::Int8Ty ||
LLVMTy == Type::Int1Ty)
LLVMTy = Type::Int32Ty;
}
ArgTypes.push_back(LLVMTy);
}
/// HandleByValArgument - This callback is invoked if the aggregate function
/// argument is passed by value. It is lowered to a parameter passed by
/// reference with an additional parameter attribute "ByVal".
void HandleByValArgument(const llvm::Type *LLVMTy, tree type) {
HandleScalarArgument(PointerType::getUnqual(LLVMTy), type);
}
};
}
static ParameterAttributes HandleArgumentExtension(tree ArgTy) {
if (TREE_CODE(ArgTy) == BOOLEAN_TYPE) {
if (TREE_INT_CST_LOW(TYPE_SIZE(ArgTy)) < INT_TYPE_SIZE)
return ParamAttr::ZExt;
} else if (TREE_CODE(ArgTy) == INTEGER_TYPE &&
TREE_INT_CST_LOW(TYPE_SIZE(ArgTy)) < INT_TYPE_SIZE) {
if (TYPE_UNSIGNED(ArgTy))
return ParamAttr::ZExt;
else
return ParamAttr::SExt;
}
return ParamAttr::None;
}
/// ConvertParamListToLLVMSignature - This method is used to build the argument
/// type list for K&R prototyped functions. In this case, we have to figure out
/// the type list (to build a FunctionType) from the actual DECL_ARGUMENTS list
/// for the function. This method takes the DECL_ARGUMENTS list (Args), and
/// fills in Result with the argument types for the function. It returns the
/// specified result type for the function.
const FunctionType *TypeConverter::
ConvertArgListToFnType(tree ReturnType, tree Args, tree static_chain,
unsigned &CallingConv, PAListPtr &PAL) {
std::vector<PATypeHolder> ArgTys;
PATypeHolder RetTy(Type::VoidTy);
FunctionTypeConversion Client(RetTy, ArgTys, CallingConv, true /*K&R*/);
TheLLVMABI<FunctionTypeConversion> ABIConverter(Client);
ABIConverter.HandleReturnType(ReturnType);
SmallVector<ParamAttrsWithIndex, 8> Attrs;
// Compute whether the result needs to be zext or sext'd.
ParameterAttributes RAttributes = HandleArgumentExtension(ReturnType);
if (RAttributes != ParamAttr::None)
Attrs.push_back(ParamAttrsWithIndex::get(0, RAttributes));
// If this is a struct-return function, the dest loc is passed in as a
// pointer. Mark that pointer as structret.
if (ABIConverter.isStructReturn())
Attrs.push_back(ParamAttrsWithIndex::get(ArgTys.size(),
ParamAttr::StructRet));
if (static_chain) {
// Pass the static chain as the first parameter.
ABIConverter.HandleArgument(TREE_TYPE(static_chain));
// Mark it as the chain argument.
Attrs.push_back(ParamAttrsWithIndex::get(ArgTys.size(),
ParamAttr::Nest));
}
for (; Args && TREE_TYPE(Args) != void_type_node; Args = TREE_CHAIN(Args)) {
tree ArgTy = TREE_TYPE(Args);
// Determine if there are any attributes for this param.
ParameterAttributes Attributes = ParamAttr::None;
ABIConverter.HandleArgument(ArgTy, &Attributes);
// Compute zext/sext attributes.
Attributes |= HandleArgumentExtension(ArgTy);
if (Attributes != ParamAttr::None)
Attrs.push_back(ParamAttrsWithIndex::get(ArgTys.size(), Attributes));
}
PAL = PAListPtr::get(Attrs.begin(), Attrs.end());
return GetFunctionType(RetTy, ArgTys, false);
}
const FunctionType *TypeConverter::
ConvertFunctionType(tree type, tree decl, tree static_chain,
unsigned &CallingConv, PAListPtr& PAL) {
PATypeHolder RetTy = Type::VoidTy;
std::vector<PATypeHolder> ArgTypes;
bool isVarArg = false;
FunctionTypeConversion Client(RetTy, ArgTypes, CallingConv, false/*not K&R*/);
TheLLVMABI<FunctionTypeConversion> ABIConverter(Client);
ABIConverter.HandleReturnType(TREE_TYPE(type));
// Allow the target to set the CC for things like fastcall etc.
#ifdef TARGET_ADJUST_LLVM_CC
TARGET_ADJUST_LLVM_CC(CallingConv, type);
#endif
// Compute attributes for return type (and function attributes).
SmallVector<ParamAttrsWithIndex, 8> Attrs;
ParameterAttributes RAttributes = ParamAttr::None;
int flags = flags_from_decl_or_type(decl ? decl : type);
// Check for 'noreturn' function attribute.
if (flags & ECF_NORETURN)
RAttributes |= ParamAttr::NoReturn;
// Check for 'nounwind' function attribute.
if (flags & ECF_NOTHROW)
RAttributes |= ParamAttr::NoUnwind;
// Check for 'readnone' function attribute.
if (flags & ECF_CONST)
RAttributes |= ParamAttr::ReadNone;
// Check for 'readonly' function attribute.
if (flags & ECF_PURE && !(flags & ECF_CONST))
RAttributes |= ParamAttr::ReadOnly;
// Since they write the return value through a pointer,
// 'sret' functions cannot be 'readnone' or 'readonly'.
if (ABIConverter.isStructReturn())
RAttributes &= ~(ParamAttr::ReadNone|ParamAttr::ReadOnly);
// Compute whether the result needs to be zext or sext'd.
RAttributes |= HandleArgumentExtension(TREE_TYPE(type));
if (RAttributes != ParamAttr::None)
Attrs.push_back(ParamAttrsWithIndex::get(0, RAttributes));
// If this is a struct-return function, the dest loc is passed in as a
// pointer. Mark that pointer as structret.
if (ABIConverter.isStructReturn())
Attrs.push_back(ParamAttrsWithIndex::get(ArgTypes.size(),
ParamAttr::StructRet));
if (static_chain) {
// Pass the static chain as the first parameter.
ABIConverter.HandleArgument(TREE_TYPE(static_chain));
// Mark it as the chain argument.
Attrs.push_back(ParamAttrsWithIndex::get(ArgTypes.size(),
ParamAttr::Nest));
}
// If the target has regparam parameters, allow it to inspect the function
// type.
int local_regparam = 0;
#ifdef LLVM_TARGET_ENABLE_REGPARM
LLVM_TARGET_INIT_REGPARM(local_regparam, type);
#endif // LLVM_TARGET_ENABLE_REGPARM
// Keep track of whether we see a byval argument.
bool HasByVal = false;
// Check if we have a corresponding decl to inspect.
tree DeclArgs = (decl) ? DECL_ARGUMENTS(decl) : NULL;
// Loop over all of the arguments, adding them as we go.
tree Args = TYPE_ARG_TYPES(type);
for (; Args && TREE_VALUE(Args) != void_type_node; Args = TREE_CHAIN(Args)){
tree ArgTy = TREE_VALUE(Args);
if (!isPassedByInvisibleReference(ArgTy) &&
isa<OpaqueType>(ConvertType(ArgTy))) {
// If we are passing an opaque struct by value, we don't know how many
// arguments it will turn into. Because we can't handle this yet,
// codegen the prototype as (...).
if (CallingConv == CallingConv::C)
ArgTypes.clear();
else
// Don't nuke last argument.
ArgTypes.erase(ArgTypes.begin()+1, ArgTypes.end());
Args = 0;
break;
}
// Determine if there are any attributes for this param.
ParameterAttributes Attributes = ParamAttr::None;
ABIConverter.HandleArgument(ArgTy, &Attributes);
// Compute zext/sext attributes.
Attributes |= HandleArgumentExtension(ArgTy);
// Compute noalias attributes. If we have a decl for the function
// inspect it for restrict qualifiers, otherwise try the argument
// types.
tree RestrictArgTy = (DeclArgs) ? TREE_TYPE(DeclArgs) : ArgTy;
if (TREE_CODE(RestrictArgTy) == POINTER_TYPE ||
TREE_CODE(RestrictArgTy) == REFERENCE_TYPE) {
if (TYPE_RESTRICT(RestrictArgTy))
Attributes |= ParamAttr::NoAlias;
}
#ifdef LLVM_TARGET_ENABLE_REGPARM
// Allow the target to mark this as inreg.
if (TREE_CODE(ArgTy) == INTEGER_TYPE || TREE_CODE(ArgTy) == POINTER_TYPE)
LLVM_ADJUST_REGPARM_ATTRIBUTE(Attributes,
TREE_INT_CST_LOW(TYPE_SIZE(ArgTy)),
local_regparam);
#endif // LLVM_TARGET_ENABLE_REGPARM
if (Attributes != ParamAttr::None) {
HasByVal |= Attributes & ParamAttr::ByVal;
Attrs.push_back(ParamAttrsWithIndex::get(ArgTypes.size(), Attributes));
}
if (DeclArgs)
DeclArgs = TREE_CHAIN(DeclArgs);
}
// If there is a byval argument then it is not safe to mark the function
// 'readnone' or 'readonly': gcc permits a 'const' or 'pure' function to
// write to struct arguments passed by value, but in LLVM this becomes a
// write through the byval pointer argument, which LLVM does not allow for
// readonly/readnone functions.
if (HasByVal && Attrs[0].Index == 0) {
ParameterAttributes &RAttrs = Attrs[0].Attrs;
RAttrs &= ~(ParamAttr::ReadNone | ParamAttr::ReadOnly);
if (RAttrs == ParamAttr::None)
Attrs.erase(Attrs.begin());
}
// If the argument list ends with a void type node, it isn't vararg.
isVarArg = (Args == 0);
assert(RetTy && "Return type not specified!");
// Finally, make the function type and result attributes.
PAL = PAListPtr::get(Attrs.begin(), Attrs.end());
return GetFunctionType(RetTy, ArgTypes, isVarArg);
}
//===----------------------------------------------------------------------===//
// RECORD/Struct Conversion Routines
//===----------------------------------------------------------------------===//
/// StructTypeConversionInfo - A temporary structure that is used when
/// translating a RECORD_TYPE to an LLVM type.
struct StructTypeConversionInfo {
std::vector<const Type*> Elements;
std::vector<uint64_t> ElementOffsetInBytes;
std::vector<uint64_t> ElementSizeInBytes;
std::vector<bool> PaddingElement; // True if field is used for padding
const TargetData &TD;
unsigned GCCStructAlignmentInBytes;
bool Packed; // True if struct is packed
bool AllBitFields; // True if all struct fields are bit fields
bool LastFieldStartsAtNonByteBoundry;
unsigned ExtraBitsAvailable; // Non-zero if last field is bit field and it
// does not use all allocated bits
StructTypeConversionInfo(TargetMachine &TM, unsigned GCCAlign, bool P)
: TD(*TM.getTargetData()), GCCStructAlignmentInBytes(GCCAlign),
Packed(P), AllBitFields(true), LastFieldStartsAtNonByteBoundry(false),
ExtraBitsAvailable(0) {}
void lastFieldStartsAtNonByteBoundry(bool value) {
LastFieldStartsAtNonByteBoundry = value;
}
void extraBitsAvailable (unsigned E) {
ExtraBitsAvailable = E;
}
bool isPacked() { return Packed; }
void markAsPacked() {
Packed = true;
}
void allFieldsAreNotBitFields() {
AllBitFields = false;
// Next field is not a bitfield.
LastFieldStartsAtNonByteBoundry = false;
}
unsigned getGCCStructAlignmentInBytes() const {
return GCCStructAlignmentInBytes;
}
/// getTypeAlignment - Return the alignment of the specified type in bytes.
///
unsigned getTypeAlignment(const Type *Ty) const {
return Packed ? 1 : TD.getABITypeAlignment(Ty);
}
/// getTypeSize - Return the size of the specified type in bytes.
///
unsigned getTypeSize(const Type *Ty) const {
return Packed ? TD.getTypeStoreSize(Ty) : TD.getABITypeSize(Ty);
}
/// getLLVMType - Return the LLVM type for the specified object.
///
const Type *getLLVMType() const {
// Use Packed type if Packed is set or all struct fields are bitfields.
// Empty struct is not packed unless packed is set.
return StructType::get(Elements,
Packed || (!Elements.empty() && AllBitFields));
}
/// getSizeAsLLVMStruct - Return the size of this struct if it were converted
/// to an LLVM type. This is the end of last element push an alignment pad at
/// the end.
uint64_t getSizeAsLLVMStruct() const {
if (Elements.empty()) return 0;
unsigned MaxAlign = 1;
if (!Packed && !AllBitFields)
for (unsigned i = 0, e = Elements.size(); i != e; ++i)
MaxAlign = std::max(MaxAlign, getTypeAlignment(Elements[i]));
uint64_t Size = ElementOffsetInBytes.back()+ElementSizeInBytes.back();
return (Size+MaxAlign-1) & ~(MaxAlign-1);
}
// If this is a Packed struct and ExtraBitsAvailable is not zero then
// remove Extra bytes if ExtraBitsAvailable > 8.
void RemoveExtraBytes () {
unsigned NoOfBytesToRemove = ExtraBitsAvailable/8;
if (!Packed && !AllBitFields)
return;
if (NoOfBytesToRemove == 0)
return;
const Type *LastType = Elements.back();
unsigned PadBytes = 0;
if (LastType == Type::Int8Ty)
PadBytes = 1 - NoOfBytesToRemove;
else if (LastType == Type::Int16Ty)
PadBytes = 2 - NoOfBytesToRemove;
else if (LastType == Type::Int32Ty)
PadBytes = 4 - NoOfBytesToRemove;
else if (LastType == Type::Int64Ty)
PadBytes = 8 - NoOfBytesToRemove;
else
return;
assert (PadBytes > 0 && "Unable to remove extra bytes");
// Update last element type and size, element offset is unchanged.
const Type *Pad = ArrayType::get(Type::Int8Ty, PadBytes);
unsigned OriginalSize = ElementSizeInBytes.back();
Elements.pop_back();
Elements.push_back(Pad);
ElementSizeInBytes.pop_back();
ElementSizeInBytes.push_back(OriginalSize - NoOfBytesToRemove);
}
/// ResizeLastElementIfOverlapsWith - If the last element in the struct
/// includes the specified byte, remove it. Return true struct
/// layout is sized properly. Return false if unable to handle ByteOffset.
/// In this case caller should redo this struct as a packed structure.
bool ResizeLastElementIfOverlapsWith(uint64_t ByteOffset, tree Field,
const Type *Ty) {
const Type *SavedTy = NULL;
if (!Elements.empty()) {
assert(ElementOffsetInBytes.back() <= ByteOffset &&
"Cannot go backwards in struct");
SavedTy = Elements.back();
if (ElementOffsetInBytes.back()+ElementSizeInBytes.back() > ByteOffset) {
// The last element overlapped with this one, remove it.
Elements.pop_back();
ElementOffsetInBytes.pop_back();
ElementSizeInBytes.pop_back();
PaddingElement.pop_back();
}
}
// Get the LLVM type for the field. If this field is a bitfield, use the
// declared type, not the shrunk-to-fit type that GCC gives us in TREE_TYPE.
unsigned ByteAlignment = getTypeAlignment(Ty);
unsigned NextByteOffset = getNewElementByteOffset(ByteAlignment);
if (NextByteOffset > ByteOffset ||
ByteAlignment > getGCCStructAlignmentInBytes()) {
// LLVM disagrees as to where this field should go in the natural field
// ordering. Therefore convert to a packed struct and try again.
return false;
}
// If alignment won't round us up to the right boundary, insert explicit
// padding.
if (NextByteOffset < ByteOffset) {
unsigned CurOffset = getNewElementByteOffset(1);
const Type *Pad = Type::Int8Ty;
if (SavedTy && LastFieldStartsAtNonByteBoundry)
// We want to reuse SavedType to access this bit field.
// e.g. struct __attribute__((packed)) {
// unsigned int A,
// unsigned short B : 6,
// C : 15;
// char D; };
// In this example, previous field is C and D is current field.
addElement(SavedTy, CurOffset, ByteOffset - CurOffset);
else if (ByteOffset - CurOffset != 1)
Pad = ArrayType::get(Pad, ByteOffset - CurOffset);
addElement(Pad, CurOffset, ByteOffset - CurOffset);
}
return true;
}
/// FieldNo - Remove the specified field and all of the fields that come after
/// it.
void RemoveFieldsAfter(unsigned FieldNo) {
Elements.erase(Elements.begin()+FieldNo, Elements.end());
ElementOffsetInBytes.erase(ElementOffsetInBytes.begin()+FieldNo,
ElementOffsetInBytes.end());
ElementSizeInBytes.erase(ElementSizeInBytes.begin()+FieldNo,
ElementSizeInBytes.end());
PaddingElement.erase(PaddingElement.begin()+FieldNo,
PaddingElement.end());
}
/// getNewElementByteOffset - If we add a new element with the specified
/// alignment, what byte offset will it land at?
unsigned getNewElementByteOffset(unsigned ByteAlignment) {
if (Elements.empty()) return 0;
uint64_t LastElementEnd =
ElementOffsetInBytes.back() + ElementSizeInBytes.back();
return (LastElementEnd+ByteAlignment-1) & ~(ByteAlignment-1);
}
/// addElement - Add an element to the structure with the specified type,
/// offset and size.
void addElement(const Type *Ty, uint64_t Offset, uint64_t Size,
bool ExtraPadding = false) {
Elements.push_back(Ty);
ElementOffsetInBytes.push_back(Offset);
ElementSizeInBytes.push_back(Size);
PaddingElement.push_back(ExtraPadding);
lastFieldStartsAtNonByteBoundry(false);
ExtraBitsAvailable = 0;
}
/// getFieldEndOffsetInBytes - Return the byte offset of the byte immediately
/// after the specified field. For example, if FieldNo is 0 and the field
/// is 4 bytes in size, this will return 4.
unsigned getFieldEndOffsetInBytes(unsigned FieldNo) const {
assert(FieldNo < ElementOffsetInBytes.size() && "Invalid field #!");
return ElementOffsetInBytes[FieldNo]+ElementSizeInBytes[FieldNo];
}
/// getEndUnallocatedByte - Return the first byte that isn't allocated at the
/// end of a structure. For example, for {}, it's 0, for {int} it is 4, for
/// {int,short}, it is 6.
unsigned getEndUnallocatedByte() const {
if (ElementOffsetInBytes.empty()) return 0;
return getFieldEndOffsetInBytes(ElementOffsetInBytes.size()-1);
}
/// getLLVMFieldFor - When we are assigning DECL_LLVM indexes to FieldDecls,
/// this method determines which struct element to use. Since the offset of
/// the fields cannot go backwards, CurFieldNo retains the last element we
/// looked at, to keep this a nice fast linear process. If isZeroSizeField
/// is true, this should return some zero sized field that starts at the
/// specified offset.
///
/// This returns the first field that contains the specified bit.
///
unsigned getLLVMFieldFor(uint64_t FieldOffsetInBits, unsigned &CurFieldNo,
bool isZeroSizeField) {
if (!isZeroSizeField) {
// Skip over LLVM fields that start and end before the GCC field starts.
while (CurFieldNo < ElementOffsetInBytes.size() &&
getFieldEndOffsetInBytes(CurFieldNo)*8 <= FieldOffsetInBits)
++CurFieldNo;
if (CurFieldNo < ElementOffsetInBytes.size())
return CurFieldNo;
// Otherwise, we couldn't find the field!
// FIXME: this works around a latent bug!
//assert(0 && "Could not find field!");
return ~0U;
}
// Handle zero sized fields now.
// Skip over LLVM fields that start and end before the GCC field starts.
// Such fields are always nonzero sized, and we don't want to skip past
// zero sized ones as well, which happens if you use only the Offset
// comparison.
while (CurFieldNo < ElementOffsetInBytes.size() &&
getFieldEndOffsetInBytes(CurFieldNo)*8 <= FieldOffsetInBits &&
ElementSizeInBytes[CurFieldNo] != 0)
++CurFieldNo;
// If the next field is zero sized, advance past this one. This is a nicety
// that causes us to assign C fields different LLVM fields in cases like
// struct X {}; struct Y { struct X a, b, c };
if (CurFieldNo+1 < ElementOffsetInBytes.size() &&
ElementSizeInBytes[CurFieldNo+1] == 0) {
return CurFieldNo++;
}
// Otherwise, if this is a zero sized field, return it.
if (CurFieldNo < ElementOffsetInBytes.size() &&
ElementSizeInBytes[CurFieldNo] == 0) {
return CurFieldNo;
}
// Otherwise, we couldn't find the field!
assert(0 && "Could not find field!");
return ~0U;
}
void addNewBitField(unsigned Size, unsigned FirstUnallocatedByte);
void dump() const;
};
// Add new element which is a bit field. Size is not the size of bit filed,
// but size of bits required to determine type of new Field which will be
// used to access this bit field.
void StructTypeConversionInfo::addNewBitField(unsigned Size,
unsigned FirstUnallocatedByte) {
// Figure out the LLVM type that we will use for the new field.
// Note, Size is not necessarily size of the new field. It indicates
// additional bits required after FirstunallocatedByte to cover new field.
const Type *NewFieldTy;
if (Size <= 8)
NewFieldTy = Type::Int8Ty;
else if (Size <= 16)
NewFieldTy = Type::Int16Ty;
else if (Size <= 32)
NewFieldTy = Type::Int32Ty;
else {
assert(Size <= 64 && "Bitfield too large!");
NewFieldTy = Type::Int64Ty;
}
// Check that the alignment of NewFieldTy won't cause a gap in the structure!
unsigned ByteAlignment = getTypeAlignment(NewFieldTy);
if (FirstUnallocatedByte & (ByteAlignment-1)) {
// Instead of inserting a nice whole field, insert a small array of ubytes.
NewFieldTy = ArrayType::get(Type::Int8Ty, (Size+7)/8);
}
// Finally, add the new field.
addElement(NewFieldTy, FirstUnallocatedByte, getTypeSize(NewFieldTy));
ExtraBitsAvailable = NewFieldTy->getPrimitiveSizeInBits() - Size;
}
void StructTypeConversionInfo::dump() const {
std::cerr << "Info has " << Elements.size() << " fields:\n";
for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
std::cerr << " Offset = " << ElementOffsetInBytes[i]
<< " Size = " << ElementSizeInBytes[i]
<< " Type = ";
WriteTypeSymbolic(std::cerr, Elements[i], TheModule) << "\n";
}
}
std::map<const Type *, StructTypeConversionInfo *> StructTypeInfoMap;
/// Return true if and only if field no. N from struct type T is a padding
/// element added to match llvm struct type size and gcc struct type size.
bool isPaddingElement(const Type *Ty, unsigned index) {
StructTypeConversionInfo *Info = StructTypeInfoMap[Ty];
// If info is not available then be conservative and return false.
if (!Info)
return false;
assert ( Info->Elements.size() == Info->PaddingElement.size()
&& "Invalid StructTypeConversionInfo");
assert ( index < Info->PaddingElement.size()
&& "Invalid PaddingElement index");
return Info->PaddingElement[index];
}
/// OldTy and NewTy are union members. If they are representing
/// structs then adjust their PaddingElement bits. Padding
/// field in one struct may not be a padding field in another
/// struct.
void adjustPaddingElement(const Type *OldTy, const Type *NewTy) {
StructTypeConversionInfo *OldInfo = StructTypeInfoMap[OldTy];
StructTypeConversionInfo *NewInfo = StructTypeInfoMap[NewTy];
if (!OldInfo || !NewInfo)
return;
/// FIXME : Find overlapping padding fields and preserve their
/// isPaddingElement bit. For now, clear all isPaddingElement bits.
for (unsigned i = 0, size = NewInfo->PaddingElement.size(); i != size; ++i)
NewInfo->PaddingElement[i] = false;
for (unsigned i = 0, size = OldInfo->PaddingElement.size(); i != size; ++i)
OldInfo->PaddingElement[i] = false;
}
/// DecodeStructFields - This method decodes the specified field, if it is a
/// FIELD_DECL, adding or updating the specified StructTypeConversionInfo to
/// reflect it. Return tree if field is decode correctly. Otherwise return
/// false.
bool TypeConverter::DecodeStructFields(tree Field,
StructTypeConversionInfo &Info) {
if (TREE_CODE(Field) != FIELD_DECL ||
TREE_CODE(DECL_FIELD_OFFSET(Field)) != INTEGER_CST)
return true;
// Handle bit-fields specially.
if (DECL_BIT_FIELD_TYPE(Field)) {
// Bit-field type does not influence structure alignment.
// For example, struct A { char a; short b; int c:25; char d; } does not
// have 4 byte alignment. To enforce this rule, always use packed struct.
if (!Info.isPacked())
return false;
DecodeStructBitField(Field, Info);
return true;
}
Info.allFieldsAreNotBitFields();
// Get the starting offset in the record.
unsigned StartOffsetInBits = getFieldOffsetInBits(Field);
assert((StartOffsetInBits & 7) == 0 && "Non-bit-field has non-byte offset!");
unsigned StartOffsetInBytes = StartOffsetInBits/8;
const Type *Ty = ConvertType(TREE_TYPE(Field));
// Pop any previous elements out of the struct if they overlap with this one.
// This can happen when the C++ front-end overlaps fields with tail padding in
// C++ classes.
if (!Info.ResizeLastElementIfOverlapsWith(StartOffsetInBytes, Field, Ty)) {
// LLVM disagrees as to where this field should go in the natural field
// ordering. Therefore convert to a packed struct and try again.
return false;
}
else if (TYPE_USER_ALIGN(TREE_TYPE(Field))
&& DECL_ALIGN_UNIT(Field) != Info.getTypeAlignment(Ty)
&& !Info.isPacked()) {
// If Field has user defined alignment and it does not match Ty alignment
// then convert to a packed struct and try again.
return false;
} else
// At this point, we know that adding the element will happen at the right
// offset. Add it.
Info.addElement(Ty, StartOffsetInBytes, Info.getTypeSize(Ty));
return true;
}
/// DecodeStructBitField - This method decodes the specified bit-field, adding
/// or updating the specified StructTypeConversionInfo to reflect it.
///
/// Note that in general, we cannot produce a good covering of struct fields for
/// bitfields. As such, we only make sure that all bits in a struct that
/// correspond to a bitfield are represented in the LLVM struct with
/// (potentially multiple) integer fields of integer type. This ensures that
/// initialized globals with bitfields can have the initializers for the
/// bitfields specified.
void TypeConverter::DecodeStructBitField(tree_node *Field,
StructTypeConversionInfo &Info) {
unsigned FieldSizeInBits = TREE_INT_CST_LOW(DECL_SIZE(Field));
if (DECL_PACKED(Field))
// Individual fields can be packed.
Info.markAsPacked();
if (FieldSizeInBits == 0) // Ignore 'int:0', which just affects layout.
return;
// Get the starting offset in the record.
unsigned StartOffsetInBits = getFieldOffsetInBits(Field);
unsigned EndBitOffset = FieldSizeInBits+StartOffsetInBits;
// If the last inserted LLVM field completely contains this bitfield, just
// ignore this field.
if (!Info.Elements.empty()) {
unsigned LastFieldBitOffset = Info.ElementOffsetInBytes.back()*8;
unsigned LastFieldBitSize = Info.ElementSizeInBytes.back()*8;
assert(LastFieldBitOffset <= StartOffsetInBits &&
"This bitfield isn't part of the last field!");
if (EndBitOffset <= LastFieldBitOffset+LastFieldBitSize &&
LastFieldBitOffset+LastFieldBitSize >= StartOffsetInBits) {
// Already contained in previous field. Update remaining extra bits that
// are available.
Info.extraBitsAvailable(Info.getEndUnallocatedByte()*8 - EndBitOffset);
return;
}
}
// Otherwise, this bitfield lives (potentially) partially in the preceeding
// field and in fields that exist after it. Add integer-typed fields to the
// LLVM struct such that there are no holes in the struct where the bitfield
// is: these holes would make it impossible to statically initialize a global
// of this type that has an initializer for the bitfield.
// Compute the number of bits that we need to add to this struct to cover
// this field.
unsigned FirstUnallocatedByte = Info.getEndUnallocatedByte();
unsigned StartOffsetFromByteBoundry = StartOffsetInBits & 7;
if (StartOffsetInBits < FirstUnallocatedByte*8) {
unsigned AvailableBits = FirstUnallocatedByte * 8 - StartOffsetInBits;
// This field's starting point is already allocated.
if (StartOffsetFromByteBoundry == 0) {
// This field starts at byte boundry. Need to allocate space
// for additional bytes not yet allocated.
unsigned NumBitsToAdd = FieldSizeInBits - AvailableBits;
Info.addNewBitField(NumBitsToAdd, FirstUnallocatedByte);
return;
}
// Otherwise, this field's starting point is inside previously used byte.
// This happens with Packed bit fields. In this case one LLVM Field is
// used to access previous field and current field.
unsigned prevFieldTypeSizeInBits =
Info.ElementSizeInBytes[Info.Elements.size() - 1] * 8;
unsigned NumBitsRequired = prevFieldTypeSizeInBits
+ (FieldSizeInBits - AvailableBits);
if (NumBitsRequired > 64) {
// Use bits from previous field.
NumBitsRequired = FieldSizeInBits - AvailableBits;
} else {
// If type used to access previous field is not large enough then
// remove previous field and insert new field that is large enough to
// hold both fields.
Info.RemoveFieldsAfter(Info.Elements.size() - 1);
for (unsigned idx = 0; idx < (prevFieldTypeSizeInBits/8); ++idx)
FirstUnallocatedByte--;
}
Info.addNewBitField(NumBitsRequired, FirstUnallocatedByte);
// Do this after adding Field.
Info.lastFieldStartsAtNonByteBoundry(true);
return;
}
if (StartOffsetInBits > FirstUnallocatedByte*8) {
// If there is padding between the last field and the struct, insert
// explicit bytes into the field to represent it.
unsigned PadBytes = 0;
unsigned PadBits = 0;
if (StartOffsetFromByteBoundry != 0) {
// New field does not start at byte boundry.
PadBits = StartOffsetInBits - (FirstUnallocatedByte*8);
PadBytes = PadBits/8;
PadBits = PadBits - PadBytes*8;
} else
PadBytes = StartOffsetInBits/8-FirstUnallocatedByte;
if (PadBytes) {
const Type *Pad = Type::Int8Ty;
if (PadBytes != 1)
Pad = ArrayType::get(Pad, PadBytes);
Info.addElement(Pad, FirstUnallocatedByte, PadBytes);
}
FirstUnallocatedByte = StartOffsetInBits/8;
// This field will use some of the bits from this PadBytes, if
// starting offset is not at byte boundry.
if (StartOffsetFromByteBoundry != 0)
FieldSizeInBits += PadBits;
}
// Now, Field starts at FirstUnallocatedByte and everything is aligned.
Info.addNewBitField(FieldSizeInBits, FirstUnallocatedByte);
}
/// ConvertRECORD - We know that 'type' is a RECORD_TYPE: convert it to an LLVM
/// type.
const Type *TypeConverter::ConvertRECORD(tree type, tree orig_type) {
if (const Type *Ty = GET_TYPE_LLVM(type)) {
// If we already compiled this type, and if it was not a forward
// definition that is now defined, use the old type.
if (!isa<OpaqueType>(Ty) || TYPE_SIZE(type) == 0)
return Ty;
}
if (TYPE_SIZE(type) == 0) { // Forward declaration?
const Type *Ty = OpaqueType::get();
TheModule->addTypeName(GetTypeName("struct.", orig_type), Ty);
return TypeDB.setType(type, Ty);
}
// Note that we are compiling a struct now.
bool OldConvertingStruct = ConvertingStruct;
ConvertingStruct = true;
// Construct LLVM types for the base types... in order to get names for
// base classes and to ensure they are laid out.
if (tree binfo = TYPE_BINFO(type)) {
for (unsigned i = 0, e = BINFO_N_BASE_BINFOS(binfo); i != e; ++i)
ConvertType(BINFO_TYPE(BINFO_BASE_BINFO(binfo, i)));
}
StructTypeConversionInfo *Info =
new StructTypeConversionInfo(*TheTarget, TYPE_ALIGN_UNIT(type),
TYPE_PACKED(type));
// Convert over all of the elements of the struct.
bool retryAsPackedStruct = false;
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (DecodeStructFields(Field, *Info) == false) {
retryAsPackedStruct = true;
break;
}
}
if (retryAsPackedStruct) {
delete Info;
Info = new StructTypeConversionInfo(*TheTarget, TYPE_ALIGN_UNIT(type),
true);
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (DecodeStructFields(Field, *Info) == false) {
assert(0 && "Unable to decode struct fields.");
}
}
}
// If the LLVM struct requires explicit tail padding to be the same size as
// the GCC struct, insert tail padding now. This handles, e.g., "{}" in C++.
if (TYPE_SIZE(type) && TREE_CODE(TYPE_SIZE(type)) == INTEGER_CST) {
uint64_t GCCTypeSize = ((uint64_t)TREE_INT_CST_LOW(TYPE_SIZE(type))+7)/8;
uint64_t LLVMStructSize = Info->getSizeAsLLVMStruct();
if (LLVMStructSize > GCCTypeSize) {
Info->RemoveExtraBytes();
LLVMStructSize = Info->getSizeAsLLVMStruct();
}
if (LLVMStructSize != GCCTypeSize) {
assert(LLVMStructSize < GCCTypeSize &&
"LLVM type size doesn't match GCC type size!");
uint64_t LLVMLastElementEnd = Info->getNewElementByteOffset(1);
// If only one byte is needed then insert i8.
if (GCCTypeSize-LLVMLastElementEnd == 1)
Info->addElement(Type::Int8Ty, 1, 1);
else {
if ( ((GCCTypeSize-LLVMStructSize) % 4) == 0) {
// insert array of i32
unsigned Int32ArraySize = (GCCTypeSize-LLVMStructSize)/4;
const Type *PadTy = ArrayType::get(Type::Int32Ty, Int32ArraySize);
Info->addElement(PadTy, GCCTypeSize - LLVMLastElementEnd,
Int32ArraySize, true /* Padding Element */);
} else {
const Type *PadTy =
ArrayType::get(Type::Int8Ty, GCCTypeSize-LLVMStructSize);
Info->addElement(PadTy, GCCTypeSize - LLVMLastElementEnd,
GCCTypeSize - LLVMLastElementEnd,
true /* Padding Element */);
}
}
}
} else
Info->RemoveExtraBytes();
// Now that the LLVM struct is finalized, figure out a safe place to index to
// and set the DECL_LLVM values for each FieldDecl that doesn't start at a
// variable offset.
unsigned CurFieldNo = 0;
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field))
if (TREE_CODE(Field) == FIELD_DECL &&
TREE_CODE(DECL_FIELD_OFFSET(Field)) == INTEGER_CST) {
unsigned FieldOffsetInBits = getFieldOffsetInBits(Field);
tree FieldType = TREE_TYPE(Field);
// If this is a bitfield, we may want to adjust the FieldOffsetInBits to
// produce safe code. In particular, bitfields will be loaded/stored as
// their *declared* type, not the smallest integer type that contains
// them. As such, we need to respect the alignment of the declared type.
if (tree DeclaredType = DECL_BIT_FIELD_TYPE(Field)) {
// If this is a bitfield, the declared type must be an integral type.
const Type *DeclFieldTy = ConvertType(DeclaredType);
unsigned DeclBitAlignment = Info->getTypeAlignment(DeclFieldTy)*8;
FieldOffsetInBits &= ~(DeclBitAlignment-1ULL);
// When we fix the field alignment, we must restart the FieldNo search
// because the FieldOffsetInBits can be lower than it was in the
// previous iteration.
CurFieldNo = 0;
}
// Figure out if this field is zero bits wide, e.g. {} or [0 x int]. Do
// not include variable sized fields here.
bool isZeroSizeField = !TYPE_SIZE(FieldType) ||
integer_zerop(TYPE_SIZE(FieldType));
unsigned FieldNo =
Info->getLLVMFieldFor(FieldOffsetInBits, CurFieldNo, isZeroSizeField);
SET_DECL_LLVM(Field, ConstantInt::get(Type::Int32Ty, FieldNo));
}
const Type *ResultTy = Info->getLLVMType();
StructTypeInfoMap[ResultTy] = Info;
const OpaqueType *OldTy = cast_or_null<OpaqueType>(GET_TYPE_LLVM(type));
TypeDB.setType(type, ResultTy);
// If there was a forward declaration for this type that is now resolved,
// refine anything that used it to the new type.
if (OldTy)
const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
// Finally, set the name for the type.
TheModule->addTypeName(GetTypeName("struct.", orig_type),
GET_TYPE_LLVM(type));
// We have finished converting this struct. See if the is the outer-most
// struct being converted by ConvertType.
ConvertingStruct = OldConvertingStruct;
if (!ConvertingStruct) {
// If this is the outer-most level of structness, resolve any pointers
// that were deferred.
while (!PointersToReresolve.empty()) {
if (tree PtrTy = PointersToReresolve.back()) {
ConvertType(PtrTy); // Reresolve this pointer type.
assert((PointersToReresolve.empty() ||
PointersToReresolve.back() != PtrTy) &&
"Something went wrong with pointer resolution!");
} else {
// Null marker element.
PointersToReresolve.pop_back();
}
}
}
return GET_TYPE_LLVM(type);
}
/// ConvertUNION - We know that 'type' is a UNION_TYPE: convert it to an LLVM
/// type.
const Type *TypeConverter::ConvertUNION(tree type, tree orig_type) {
if (const Type *Ty = GET_TYPE_LLVM(type)) {
// If we already compiled this type, and if it was not a forward
// definition that is now defined, use the old type.
if (!isa<OpaqueType>(Ty) || TYPE_SIZE(type) == 0)
return Ty;
}
if (TYPE_SIZE(type) == 0) { // Forward declaraion?
const Type *Ty = OpaqueType::get();
TheModule->addTypeName(GetTypeName("union.", orig_type), Ty);
return TypeDB.setType(type, Ty);
}
// If this is a union with the transparent_union attribute set, it is
// treated as if it were just the same as its first type.
if (TYPE_TRANSPARENT_UNION(type)) {
tree Field = TYPE_FIELDS(type);
assert(Field && "Transparent union must have some elements!");
while (TREE_CODE(Field) != FIELD_DECL) {
Field = TREE_CHAIN(Field);
assert(Field && "Transparent union must have some elements!");
}
return TypeDB.setType(type, ConvertType(TREE_TYPE(Field)));
}
// Note that we are compiling a struct now.
bool OldConvertingStruct = ConvertingStruct;
ConvertingStruct = true;
// Find the type with the largest aligment, and if we have multiple types with
// the same alignment, select one with largest size. If type with max. align
// is smaller then other types then we will add padding later on anyway to
// match union size.
const TargetData &TD = getTargetData();
const Type *UnionTy = 0;
unsigned MaxSize = 0, MaxAlign = 0;
Value *Idx = Constant::getNullValue(Type::Int32Ty);
for (tree Field = TYPE_FIELDS(type); Field; Field = TREE_CHAIN(Field)) {
if (TREE_CODE(Field) != FIELD_DECL) continue;
assert(getFieldOffsetInBits(Field) == 0 && "Union with non-zero offset?");
// Set the field idx to zero for all fields.
SET_DECL_LLVM(Field, Idx);
const Type *TheTy = ConvertType(TREE_TYPE(Field));
bool isPacked = false;
unsigned Size = TD.getABITypeSize(TheTy);
unsigned Align = TD.getABITypeAlignment(TheTy);
if (const StructType *STy = dyn_cast<StructType>(TheTy))
if (STy->isPacked())
isPacked = true;
adjustPaddingElement(UnionTy, TheTy);
// Select TheTy as union type if it meets one of the following criteria
// 1) UnionTy is 0
// 2) TheTy alignment is more then UnionTy
// 3) TheTy size is greater than UnionTy size and TheTy alignment is equal to UnionTy
// 4) TheTy size is greater then UnionTy size and TheTy is packed
bool useTheTy = false;
if (UnionTy == 0)
useTheTy = true;
else if (Align > MaxAlign)
useTheTy = true;
else if (MaxAlign == Align && Size > MaxSize)
useTheTy = true;
else if (isPacked && Size > MaxSize)
useTheTy = true;
if (useTheTy) {
UnionTy = TheTy;
MaxSize = MAX(MaxSize, Size);
MaxAlign = Align;
}
}
std::vector<const Type*> UnionElts;
unsigned UnionSize = 0;
if (UnionTy) { // Not an empty union.
UnionSize = TD.getABITypeSize(UnionTy);
UnionElts.push_back(UnionTy);
}
// If the LLVM struct requires explicit tail padding to be the same size as
// the GCC union, insert tail padding now. This handles cases where the union
// has larger alignment than the largest member does, thus requires tail
// padding.
if (TYPE_SIZE(type) && TREE_CODE(TYPE_SIZE(type)) == INTEGER_CST) {
unsigned GCCTypeSize = ((unsigned)TREE_INT_CST_LOW(TYPE_SIZE(type))+7)/8;
if (UnionSize != GCCTypeSize) {
assert(UnionSize < GCCTypeSize &&
"LLVM type size doesn't match GCC type size!");
const Type *PadTy = Type::Int8Ty;
if (GCCTypeSize-UnionSize != 1)
PadTy = ArrayType::get(PadTy, GCCTypeSize-UnionSize);
UnionElts.push_back(PadTy);
}
}
// If this is an empty union, but there is tail padding, make a filler.
if (UnionTy == 0) {
unsigned Size = ((unsigned)TREE_INT_CST_LOW(TYPE_SIZE(type))+7)/8;
UnionTy = Type::Int8Ty;
if (Size != 1) UnionTy = ArrayType::get(UnionTy, Size);
}
const Type *ResultTy = StructType::get(UnionElts, false);
const OpaqueType *OldTy = cast_or_null<OpaqueType>(GET_TYPE_LLVM(type));
TypeDB.setType(type, ResultTy);
// If there was a forward declaration for this type that is now resolved,
// refine anything that used it to the new type.
if (OldTy)
const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
// Finally, set the name for the type.
TheModule->addTypeName(GetTypeName("struct.", orig_type),
GET_TYPE_LLVM(type));
// We have finished converting this union. See if the is the outer-most
// union being converted by ConvertType.
ConvertingStruct = OldConvertingStruct;
if (!ConvertingStruct) {
// If this is the outer-most level of structness, resolve any pointers
// that were deferred.
while (!PointersToReresolve.empty()) {
if (tree PtrTy = PointersToReresolve.back()) {
ConvertType(PtrTy); // Reresolve this pointer type.
assert((PointersToReresolve.empty() ||
PointersToReresolve.back() != PtrTy) &&
"Something went wrong with pointer resolution!");
} else {
// Null marker element.
PointersToReresolve.pop_back();
}
}
}
return GET_TYPE_LLVM(type);
}
/* APPLE LOCAL end LLVM (ENTIRE FILE!) */