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llvm-project/clang/lib/CodeGen/CGBlocks.cpp

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//===--- CGBlocks.cpp - Emit LLVM Code for declarations -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit blocks.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "llvm/Module.h"
#include "llvm/Target/TargetData.h"
#include <algorithm>
using namespace clang;
using namespace CodeGen;
enum {
BLOCK_NEEDS_FREE = (1 << 24),
BLOCK_HAS_COPY_DISPOSE = (1 << 25),
BLOCK_HAS_CXX_OBJ = (1 << 26),
BLOCK_IS_GC = (1 << 27),
BLOCK_IS_GLOBAL = (1 << 28),
BLOCK_HAS_DESCRIPTOR = (1 << 29)
};
llvm::Constant *CodeGenFunction::BuildDescriptorBlockDecl(uint64_t Size) {
const llvm::PointerType *PtrToInt8Ty
= llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
const llvm::Type *UnsignedLongTy
= CGM.getTypes().ConvertType(getContext().UnsignedLongTy);
llvm::Constant *C;
std::vector<llvm::Constant*> Elts;
// reserved
C = llvm::ConstantInt::get(UnsignedLongTy, 0);
Elts.push_back(C);
// Size
// FIXME: What is the right way to say this doesn't fit? We should give
// a user diagnostic in that case. Better fix would be to change the
// API to size_t.
C = llvm::ConstantInt::get(UnsignedLongTy, Size);
Elts.push_back(C);
if (BlockHasCopyDispose) {
// copy_func_helper_decl
// FIXME: implement
C = llvm::ConstantInt::get(UnsignedLongTy, 0);
C = llvm::ConstantExpr::getBitCast(C, PtrToInt8Ty);
Elts.push_back(C);
// destroy_func_decl
// FIXME: implement
C = llvm::ConstantInt::get(UnsignedLongTy, 0);
C = llvm::ConstantExpr::getBitCast(C, PtrToInt8Ty);
Elts.push_back(C);
}
C = llvm::ConstantStruct::get(Elts);
C = new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalValue::InternalLinkage,
C, "__block_descriptor_tmp", &CGM.getModule());
return C;
}
llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() {
if (NSConcreteGlobalBlock)
return NSConcreteGlobalBlock;
const llvm::PointerType *PtrToInt8Ty
= llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
// FIXME: We should have a CodeGenModule::AddRuntimeVariable that does the
// same thing as CreateRuntimeFunction if there's already a variable with
// the same name.
NSConcreteGlobalBlock
= new llvm::GlobalVariable(PtrToInt8Ty, false,
llvm::GlobalValue::ExternalLinkage,
0, "_NSConcreteGlobalBlock",
&getModule());
return NSConcreteGlobalBlock;
}
llvm::Constant *CodeGenModule::getNSConcreteStackBlock() {
if (NSConcreteStackBlock)
return NSConcreteStackBlock;
const llvm::PointerType *PtrToInt8Ty
= llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
// FIXME: We should have a CodeGenModule::AddRuntimeVariable that does the
// same thing as CreateRuntimeFunction if there's already a variable with
// the same name.
NSConcreteStackBlock
= new llvm::GlobalVariable(PtrToInt8Ty, false,
llvm::GlobalValue::ExternalLinkage,
0, "_NSConcreteStackBlock",
&getModule());
return NSConcreteStackBlock;
}
// FIXME: Push most into CGM, passing down a few bits, like current
// function name.
llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
bool insideFunction = false;
bool BlockRefDeclList = false;
bool BlockByrefDeclList = false;
std::vector<llvm::Constant*> Elts;
llvm::Constant *C;
llvm::Value *V;
{
// C = BuildBlockStructInitlist();
unsigned int flags = BLOCK_HAS_DESCRIPTOR;
if (BlockHasCopyDispose)
flags |= BLOCK_HAS_COPY_DISPOSE;
// __isa
C = CGM.getNSConcreteStackBlock();
if (!insideFunction ||
(!BlockRefDeclList && !BlockByrefDeclList)) {
C = CGM.getNSConcreteGlobalBlock();
flags |= BLOCK_IS_GLOBAL;
}
const llvm::PointerType *PtrToInt8Ty
= llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
C = llvm::ConstantExpr::getBitCast(C, PtrToInt8Ty);
Elts.push_back(C);
// __flags
const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
CGM.getTypes().ConvertType(CGM.getContext().IntTy));
C = llvm::ConstantInt::get(IntTy, flags);
Elts.push_back(C);
// __reserved
C = llvm::ConstantInt::get(IntTy, 0);
Elts.push_back(C);
// __invoke
const char *Name = "";
if (const NamedDecl *ND = dyn_cast<NamedDecl>(CurFuncDecl))
if (ND->getIdentifier())
Name = ND->getNameAsCString();
BlockInfo Info(0, Name);
uint64_t subBlockSize, subBlockAlign;
llvm::SmallVector<const Expr *, 8> subBlockDeclRefDecls;
llvm::Function *Fn
= CodeGenFunction(CGM).GenerateBlockFunction(BE, Info, subBlockSize,
subBlockAlign, subBlockDeclRefDecls);
Elts.push_back(Fn);
// __descriptor
Elts.push_back(BuildDescriptorBlockDecl(subBlockSize));
if (subBlockDeclRefDecls.size() == 0) {
C = llvm::ConstantStruct::get(Elts);
char Name[32];
sprintf(Name, "__block_holder_tmp_%d", CGM.getGlobalUniqueCount());
C = new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalValue::InternalLinkage,
C, Name, &CGM.getModule());
QualType BPT = BE->getType();
C = llvm::ConstantExpr::getBitCast(C, ConvertType(BPT));
return C;
}
std::vector<const llvm::Type *> Types(5+subBlockDeclRefDecls.size());
for (int i=0; i<5; ++i)
Types[i] = Elts[i]->getType();
for (unsigned i=0; i < subBlockDeclRefDecls.size(); ++i) {
const Expr *E = subBlockDeclRefDecls[i];
const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E);
QualType Ty = E->getType();
if (BDRE && BDRE->isByRef())
Ty = getContext().getPointerType(Ty);
Types[i+5] = ConvertType(Ty);
}
llvm::Type *Ty = llvm::StructType::get(Types, true);
llvm::AllocaInst *A = CreateTempAlloca(Ty);
A->setAlignment(subBlockAlign);
V = A;
for (unsigned i=0; i<5; ++i)
Builder.CreateStore(Elts[i], Builder.CreateStructGEP(V, i, "block.tmp"));
for (unsigned i=0; i < subBlockDeclRefDecls.size(); ++i)
{
// FIXME: Push const down.
Expr *E = const_cast<Expr*>(subBlockDeclRefDecls[i]);
DeclRefExpr *DR;
ValueDecl *VD;
DR = dyn_cast<DeclRefExpr>(E);
// Skip padding.
if (DR) continue;
BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E);
VD = BDRE->getDecl();
// FIXME: I want a better way to do this.
if (LocalDeclMap[VD]) {
E = new (getContext()) DeclRefExpr (cast<NamedDecl>(VD),
VD->getType(), SourceLocation(),
false, false);
}
if (BDRE->isByRef())
E = new (getContext())
UnaryOperator(E, UnaryOperator::AddrOf,
getContext().getPointerType(E->getType()),
SourceLocation());
llvm::Value* Addr = Builder.CreateStructGEP(V, i+5, "tmp");
RValue r = EmitAnyExpr(E, Addr, false);
if (r.isScalar())
Builder.CreateStore(r.getScalarVal(), Addr);
else if (r.isComplex())
// FIXME: implement
ErrorUnsupported(BE, "complex in block literal");
else if (r.isAggregate())
; // Already created into the destination
else
assert (0 && "bad block variable");
// FIXME: Ensure that the offset created by the backend for
// the struct matches the previously computed offset in BlockDecls.
}
}
QualType BPT = BE->getType();
return Builder.CreateBitCast(V, ConvertType(BPT));
}
const llvm::Type *CodeGenModule::getBlockDescriptorType() {
if (BlockDescriptorType)
return BlockDescriptorType;
const llvm::Type *UnsignedLongTy =
getTypes().ConvertType(getContext().UnsignedLongTy);
// struct __block_descriptor {
// unsigned long reserved;
// unsigned long block_size;
// };
BlockDescriptorType = llvm::StructType::get(UnsignedLongTy,
UnsignedLongTy,
NULL);
getModule().addTypeName("struct.__block_descriptor",
BlockDescriptorType);
return BlockDescriptorType;
}
const llvm::Type *
CodeGenModule::getGenericBlockLiteralType() {
if (GenericBlockLiteralType)
return GenericBlockLiteralType;
const llvm::Type *Int8PtrTy =
llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
const llvm::Type *BlockDescPtrTy =
llvm::PointerType::getUnqual(getBlockDescriptorType());
const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
getTypes().ConvertType(getContext().IntTy));
// struct __block_literal_generic {
// void *__isa;
// int __flags;
// int __reserved;
// void (*__invoke)(void *);
// struct __block_descriptor *__descriptor;
// };
GenericBlockLiteralType = llvm::StructType::get(Int8PtrTy,
IntTy,
IntTy,
Int8PtrTy,
BlockDescPtrTy,
NULL);
getModule().addTypeName("struct.__block_literal_generic",
GenericBlockLiteralType);
return GenericBlockLiteralType;
}
const llvm::Type *
CodeGenModule::getGenericExtendedBlockLiteralType() {
if (GenericExtendedBlockLiteralType)
return GenericExtendedBlockLiteralType;
const llvm::Type *Int8PtrTy =
llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
const llvm::Type *BlockDescPtrTy =
llvm::PointerType::getUnqual(getBlockDescriptorType());
const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
getTypes().ConvertType(getContext().IntTy));
// struct __block_literal_generic {
// void *__isa;
// int __flags;
// int __reserved;
// void (*__invoke)(void *);
// struct __block_descriptor *__descriptor;
// void *__copy_func_helper_decl;
// void *__destroy_func_decl;
// };
GenericExtendedBlockLiteralType = llvm::StructType::get(Int8PtrTy,
IntTy,
IntTy,
Int8PtrTy,
BlockDescPtrTy,
Int8PtrTy,
Int8PtrTy,
NULL);
getModule().addTypeName("struct.__block_literal_extended_generic",
GenericExtendedBlockLiteralType);
return GenericExtendedBlockLiteralType;
}
/// getBlockFunctionType - Given a BlockPointerType, will return the
/// function type for the block, including the first block literal argument.
static QualType getBlockFunctionType(ASTContext &Ctx,
const BlockPointerType *BPT) {
const FunctionProtoType *FTy = cast<FunctionProtoType>(BPT->getPointeeType());
llvm::SmallVector<QualType, 8> Types;
Types.push_back(Ctx.getPointerType(Ctx.VoidTy));
for (FunctionProtoType::arg_type_iterator i = FTy->arg_type_begin(),
e = FTy->arg_type_end(); i != e; ++i)
Types.push_back(*i);
return Ctx.getFunctionType(FTy->getResultType(),
&Types[0], Types.size(),
FTy->isVariadic(), 0);
}
RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr* E) {
const BlockPointerType *BPT =
E->getCallee()->getType()->getAsBlockPointerType();
llvm::Value *Callee = EmitScalarExpr(E->getCallee());
// Get a pointer to the generic block literal.
const llvm::Type *BlockLiteralTy =
llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType());
// Bitcast the callee to a block literal.
llvm::Value *BlockLiteral =
Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal");
// Get the function pointer from the literal.
llvm::Value *FuncPtr = Builder.CreateStructGEP(BlockLiteral, 3, "tmp");
llvm::Value *Func = Builder.CreateLoad(FuncPtr, false, "tmp");
// Cast the function pointer to the right type.
const llvm::Type *BlockFTy =
ConvertType(getBlockFunctionType(getContext(), BPT));
const llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
Func = Builder.CreateBitCast(Func, BlockFTyPtr);
BlockLiteral =
Builder.CreateBitCast(BlockLiteral,
llvm::PointerType::getUnqual(llvm::Type::Int8Ty),
"tmp");
// Add the block literal.
QualType VoidPtrTy = getContext().getPointerType(getContext().VoidTy);
CallArgList Args;
Args.push_back(std::make_pair(RValue::get(BlockLiteral), VoidPtrTy));
// And the rest of the arguments.
for (CallExpr::const_arg_iterator i = E->arg_begin(), e = E->arg_end();
i != e; ++i)
Args.push_back(std::make_pair(EmitAnyExprToTemp(*i),
i->getType()));
// And call the block.
return EmitCall(CGM.getTypes().getFunctionInfo(E->getType(), Args),
Func, Args);
}
llvm::Constant *
CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
// Generate the block descriptor.
const llvm::Type *UnsignedLongTy = Types.ConvertType(Context.UnsignedLongTy);
const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
getTypes().ConvertType(getContext().IntTy));
llvm::Constant *DescriptorFields[2];
// Reserved
DescriptorFields[0] = llvm::Constant::getNullValue(UnsignedLongTy);
// Block literal size. For global blocks we just use the size of the generic
// block literal struct.
uint64_t BlockLiteralSize =
TheTargetData.getTypeStoreSizeInBits(getGenericBlockLiteralType()) / 8;
DescriptorFields[1] = llvm::ConstantInt::get(UnsignedLongTy,BlockLiteralSize);
llvm::Constant *DescriptorStruct =
llvm::ConstantStruct::get(&DescriptorFields[0], 2);
llvm::GlobalVariable *Descriptor =
new llvm::GlobalVariable(DescriptorStruct->getType(), true,
llvm::GlobalVariable::InternalLinkage,
DescriptorStruct, "__block_descriptor_global",
&getModule());
// Generate the constants for the block literal.
llvm::Constant *LiteralFields[5];
CodeGenFunction::BlockInfo Info(0, n);
uint64_t subBlockSize, subBlockAlign;
llvm::SmallVector<const Expr *, 8> subBlockDeclRefDecls;
llvm::Function *Fn
= CodeGenFunction(*this).GenerateBlockFunction(BE, Info, subBlockSize,
subBlockAlign,
subBlockDeclRefDecls);
assert(subBlockSize == BlockLiteralSize
&& "no imports allowed for global block");
// isa
LiteralFields[0] = getNSConcreteGlobalBlock();
// Flags
LiteralFields[1] = llvm::ConstantInt::get(IntTy, BLOCK_IS_GLOBAL);
// Reserved
LiteralFields[2] = llvm::Constant::getNullValue(IntTy);
// Function
LiteralFields[3] = Fn;
// Descriptor
LiteralFields[4] = Descriptor;
llvm::Constant *BlockLiteralStruct =
llvm::ConstantStruct::get(&LiteralFields[0], 5);
llvm::GlobalVariable *BlockLiteral =
new llvm::GlobalVariable(BlockLiteralStruct->getType(), true,
llvm::GlobalVariable::InternalLinkage,
BlockLiteralStruct, "__block_literal_global",
&getModule());
return BlockLiteral;
}
llvm::Value *CodeGenFunction::LoadBlockStruct() {
return Builder.CreateLoad(LocalDeclMap[getBlockStructDecl()], "self");
}
llvm::Function *CodeGenFunction::GenerateBlockFunction(const BlockExpr *BExpr,
const BlockInfo& Info,
uint64_t &Size,
uint64_t &Align,
llvm::SmallVector<const Expr *, 8> &subBlockDeclRefDecls) {
const FunctionProtoType *FTy =
cast<FunctionProtoType>(BExpr->getFunctionType());
FunctionArgList Args;
const BlockDecl *BD = BExpr->getBlockDecl();
// FIXME: This leaks
ImplicitParamDecl *SelfDecl =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(SelfDecl, SelfDecl->getType()));
BlockStructDecl = SelfDecl;
for (BlockDecl::param_iterator i = BD->param_begin(),
e = BD->param_end(); i != e; ++i)
Args.push_back(std::make_pair(*i, (*i)->getType()));
const CGFunctionInfo &FI =
CGM.getTypes().getFunctionInfo(FTy->getResultType(), Args);
std::string Name = std::string("__") + Info.Name + "_block_invoke_";
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *LTy = Types.GetFunctionType(FI, FTy->isVariadic());
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
Name,
&CGM.getModule());
StartFunction(BD, FTy->getResultType(), Fn, Args,
BExpr->getBody()->getLocEnd());
EmitStmt(BExpr->getBody());
FinishFunction(cast<CompoundStmt>(BExpr->getBody())->getRBracLoc());
// The runtime needs a minimum alignment of a void *.
uint64_t MinAlign = getContext().getTypeAlign(getContext().VoidPtrTy) / 8;
BlockOffset = llvm::RoundUpToAlignment(BlockOffset, MinAlign);
Size = BlockOffset;
Align = BlockAlign;
subBlockDeclRefDecls = BlockDeclRefDecls;
return Fn;
}
uint64_t CodeGenFunction::getBlockOffset(const BlockDeclRefExpr *BDRE) {
const ValueDecl *D = dyn_cast<ValueDecl>(BDRE->getDecl());
uint64_t Size = getContext().getTypeSize(D->getType()) / 8;
uint64_t Align = getContext().getDeclAlignInBytes(D);
if (BDRE->isByRef()) {
Size = getContext().getTypeSize(getContext().VoidPtrTy) / 8;
Align = getContext().getTypeAlign(getContext().VoidPtrTy) / 8;
}
assert ((Align > 0) && "alignment must be 1 byte or more");
uint64_t OldOffset = BlockOffset;
// Ensure proper alignment, even if it means we have to have a gap
BlockOffset = llvm::RoundUpToAlignment(BlockOffset, Align);
BlockAlign = std::max(Align, BlockAlign);
uint64_t Pad = BlockOffset - OldOffset;
if (Pad) {
llvm::ArrayType::get(llvm::Type::Int8Ty, Pad);
QualType PadTy = getContext().getConstantArrayType(getContext().CharTy,
llvm::APInt(32, Pad),
ArrayType::Normal, 0);
ValueDecl *PadDecl = VarDecl::Create(getContext(), 0, SourceLocation(),
0, QualType(PadTy), VarDecl::None,
SourceLocation());
Expr *E;
E = new (getContext()) DeclRefExpr(PadDecl, PadDecl->getType(),
SourceLocation(), false, false);
BlockDeclRefDecls.push_back(E);
}
BlockDeclRefDecls.push_back(BDRE);
BlockOffset += Size;
return BlockOffset-Size;
}
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