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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 "CGDebugInfo.h"
#include "CodeGenFunction.h"
#include "CGObjCRuntime.h"
#include "CodeGenModule.h"
#include "clang/AST/DeclObjC.h"
#include "llvm/Module.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Target/TargetData.h"
#include <algorithm>
using namespace clang;
using namespace CodeGen;
CGBlockInfo::CGBlockInfo(const char *N)
: Name(N), CXXThisRef(0), NeedsObjCSelf(false) {
// Skip asm prefix, if any.
if (Name && Name[0] == '\01')
++Name;
}
llvm::Constant *CodeGenFunction::
BuildDescriptorBlockDecl(const BlockExpr *BE, const CGBlockInfo &Info,
const llvm::StructType* Ty,
llvm::Constant *BlockVarLayout,
std::vector<HelperInfo> *NoteForHelper) {
bool BlockHasCopyDispose = Info.BlockHasCopyDispose;
CharUnits Size = Info.BlockSize;
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.getQuantity());
Elts.push_back(C);
// optional copy/dispose helpers
if (BlockHasCopyDispose) {
// copy_func_helper_decl
Elts.push_back(BuildCopyHelper(Ty, NoteForHelper));
// destroy_func_decl
Elts.push_back(BuildDestroyHelper(Ty, NoteForHelper));
}
// Signature. non-optional ObjC-style method descriptor @encode sequence
std::string BlockTypeEncoding;
CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
Elts.push_back(llvm::ConstantExpr::getBitCast(
CGM.GetAddrOfConstantCString(BlockTypeEncoding), PtrToInt8Ty));
// Layout.
C = BlockVarLayout;
Elts.push_back(C);
C = llvm::ConstantStruct::get(VMContext, Elts, false);
C = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true,
llvm::GlobalValue::InternalLinkage,
C, "__block_descriptor_tmp");
return C;
}
static void CollectBlockDeclRefInfo(const Stmt *S, CGBlockInfo &Info) {
for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end();
I != E; ++I)
if (*I)
CollectBlockDeclRefInfo(*I, Info);
// We want to ensure we walk down into block literals so we can find
// all nested BlockDeclRefExprs.
if (const BlockExpr *BE = dyn_cast<BlockExpr>(S)) {
Info.InnerBlocks.insert(BE->getBlockDecl());
CollectBlockDeclRefInfo(BE->getBody(), Info);
}
else if (const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(S)) {
const ValueDecl *D = BDRE->getDecl();
// FIXME: Handle enums.
if (isa<FunctionDecl>(D))
return;
if (isa<ImplicitParamDecl>(D) &&
isa<ObjCMethodDecl>(D->getDeclContext()) &&
cast<ObjCMethodDecl>(D->getDeclContext())->getSelfDecl() == D) {
Info.NeedsObjCSelf = true;
return;
}
// Only Decls that escape are added.
if (!Info.InnerBlocks.count(D->getDeclContext()))
Info.DeclRefs.push_back(BDRE);
}
// Make sure to capture implicit 'self' references due to super calls.
else if (const ObjCMessageExpr *E = dyn_cast<ObjCMessageExpr>(S)) {
if (E->getReceiverKind() == ObjCMessageExpr::SuperClass ||
E->getReceiverKind() == ObjCMessageExpr::SuperInstance)
Info.NeedsObjCSelf = true;
}
// Getter/setter uses may also cause implicit super references,
// which we can check for with:
else if (isa<ObjCSuperExpr>(S))
Info.NeedsObjCSelf = true;
else if (isa<CXXThisExpr>(S))
Info.CXXThisRef = cast<CXXThisExpr>(S);
}
/// CanBlockBeGlobal - Given a CGBlockInfo struct, determines if a block can be
/// declared as a global variable instead of on the stack.
static bool CanBlockBeGlobal(const CGBlockInfo &Info) {
return Info.DeclRefs.empty();
}
/// AllocateAllBlockDeclRefs - Preallocate all nested BlockDeclRefExprs to
/// ensure we can generate the debug information for the parameter for the block
/// invoke function.
static void AllocateAllBlockDeclRefs(CodeGenFunction &CGF, CGBlockInfo &Info) {
if (Info.CXXThisRef)
CGF.AllocateBlockCXXThisPointer(Info.CXXThisRef);
for (size_t i = 0; i < Info.DeclRefs.size(); ++i)
CGF.AllocateBlockDecl(Info.DeclRefs[i]);
if (Info.NeedsObjCSelf) {
ValueDecl *Self = cast<ObjCMethodDecl>(CGF.CurFuncDecl)->getSelfDecl();
BlockDeclRefExpr *BDRE =
new (CGF.getContext()) BlockDeclRefExpr(Self, Self->getType(),
SourceLocation(), false);
Info.DeclRefs.push_back(BDRE);
CGF.AllocateBlockDecl(BDRE);
}
}
static unsigned computeBlockFlag(CodeGenModule &CGM,
const BlockExpr *BE, unsigned flags) {
QualType BPT = BE->getType();
const FunctionType *ftype = BPT->getPointeeType()->getAs<FunctionType>();
QualType ResultType = ftype->getResultType();
CallArgList Args;
CodeGenTypes &Types = CGM.getTypes();
const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, Args,
FunctionType::ExtInfo());
if (CGM.ReturnTypeUsesSRet(FnInfo))
flags |= CodeGenFunction::BLOCK_USE_STRET;
return flags;
}
// FIXME: Push most into CGM, passing down a few bits, like current function
// name.
llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
std::string Name = CurFn->getName();
CGBlockInfo Info(Name.c_str());
Info.InnerBlocks.insert(BE->getBlockDecl());
CollectBlockDeclRefInfo(BE->getBody(), Info);
// Check if the block can be global.
// FIXME: This test doesn't work for nested blocks yet. Longer term, I'd like
// to just have one code path. We should move this function into CGM and pass
// CGF, then we can just check to see if CGF is 0.
if (0 && CanBlockBeGlobal(Info))
return CGM.GetAddrOfGlobalBlock(BE, Name.c_str());
size_t BlockFields = 5;
std::vector<llvm::Constant*> Elts(BlockFields);
llvm::Constant *C;
llvm::Value *V;
{
llvm::Constant *BlockVarLayout;
// C = BuildBlockStructInitlist();
unsigned int flags = BLOCK_HAS_SIGNATURE;
// We run this first so that we set BlockHasCopyDispose from the entire
// block literal.
// __invoke
llvm::Function *Fn
= CodeGenFunction(CGM).GenerateBlockFunction(CurGD, BE, Info, CurFuncDecl,
BlockVarLayout,
LocalDeclMap);
BlockHasCopyDispose |= Info.BlockHasCopyDispose;
Elts[3] = Fn;
// FIXME: Don't use BlockHasCopyDispose, it is set more often then
// necessary, for example: { ^{ __block int i; ^{ i = 1; }(); }(); }
if (Info.BlockHasCopyDispose)
flags |= BLOCK_HAS_COPY_DISPOSE;
// __isa
C = CGM.getNSConcreteStackBlock();
C = llvm::ConstantExpr::getBitCast(C, PtrToInt8Ty);
Elts[0] = C;
// __flags
flags = computeBlockFlag(CGM, BE, flags);
const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
CGM.getTypes().ConvertType(CGM.getContext().IntTy));
C = llvm::ConstantInt::get(IntTy, flags);
Elts[1] = C;
// __reserved
C = llvm::ConstantInt::get(IntTy, 0);
Elts[2] = C;
if (Info.BlockLayout.empty()) {
// __descriptor
C = llvm::Constant::getNullValue(PtrToInt8Ty);
Elts[4] = BuildDescriptorBlockDecl(BE, Info, 0, C, 0);
// Optimize to being a global block.
Elts[0] = CGM.getNSConcreteGlobalBlock();
Elts[1] = llvm::ConstantInt::get(IntTy, flags|BLOCK_IS_GLOBAL);
C = llvm::ConstantStruct::get(VMContext, Elts, false);
C = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true,
llvm::GlobalValue::InternalLinkage, C,
"__block_holder_tmp_" +
llvm::Twine(CGM.getGlobalUniqueCount()));
QualType BPT = BE->getType();
C = llvm::ConstantExpr::getBitCast(C, ConvertType(BPT));
return C;
}
std::vector<const llvm::Type *> Types(BlockFields+Info.BlockLayout.size());
for (int i=0; i<4; ++i)
Types[i] = Elts[i]->getType();
Types[4] = PtrToInt8Ty;
for (unsigned i = 0, n = Info.BlockLayout.size(); i != n; ++i) {
const Expr *E = Info.BlockLayout[i];
const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E);
QualType Ty = E->getType();
if (BDRE && BDRE->isByRef()) {
Types[i+BlockFields] =
llvm::PointerType::get(BuildByRefType(BDRE->getDecl()), 0);
} else if (BDRE && BDRE->getDecl()->getType()->isReferenceType()) {
Types[i+BlockFields] = llvm::PointerType::get(ConvertType(Ty), 0);
} else
Types[i+BlockFields] = ConvertType(Ty);
}
llvm::StructType *Ty = llvm::StructType::get(VMContext, Types, true);
llvm::AllocaInst *A = CreateTempAlloca(Ty);
A->setAlignment(Info.BlockAlign.getQuantity());
V = A;
// Build layout / cleanup information for all the data entries in the
// layout, and write the enclosing fields into the type.
std::vector<HelperInfo> NoteForHelper(Info.BlockLayout.size());
unsigned NumHelpers = 0;
for (unsigned i=0; i<4; ++i)
Builder.CreateStore(Elts[i], Builder.CreateStructGEP(V, i, "block.tmp"));
for (unsigned i=0; i < Info.BlockLayout.size(); ++i) {
const Expr *E = Info.BlockLayout[i];
// Skip padding.
if (isa<DeclRefExpr>(E)) continue;
llvm::Value* Addr = Builder.CreateStructGEP(V, i+BlockFields, "tmp");
HelperInfo &Note = NoteForHelper[NumHelpers++];
Note.index = i+5;
if (isa<CXXThisExpr>(E)) {
Note.RequiresCopying = false;
Note.flag = BLOCK_FIELD_IS_OBJECT;
Builder.CreateStore(LoadCXXThis(), Addr);
continue;
}
const BlockDeclRefExpr *BDRE = cast<BlockDeclRefExpr>(E);
const ValueDecl *VD = BDRE->getDecl();
QualType T = VD->getType();
Note.RequiresCopying = BlockRequiresCopying(T);
if (BDRE->isByRef()) {
Note.flag = BLOCK_FIELD_IS_BYREF;
if (T.isObjCGCWeak())
Note.flag |= BLOCK_FIELD_IS_WEAK;
} else if (T->isBlockPointerType()) {
Note.flag = BLOCK_FIELD_IS_BLOCK;
} else {
Note.flag = BLOCK_FIELD_IS_OBJECT;
}
if (LocalDeclMap[VD]) {
if (BDRE->isByRef()) {
llvm::Value *Loc = LocalDeclMap[VD];
Loc = Builder.CreateStructGEP(Loc, 1, "forwarding");
Loc = Builder.CreateLoad(Loc);
Builder.CreateStore(Loc, Addr);
continue;
} else {
if (BDRE->getCopyConstructorExpr()) {
E = BDRE->getCopyConstructorExpr();
PushDestructorCleanup(E->getType(), Addr);
}
else {
E = new (getContext()) DeclRefExpr(const_cast<ValueDecl*>(VD),
VD->getType().getNonReferenceType(),
SourceLocation());
if (VD->getType()->isReferenceType()) {
E = new (getContext())
UnaryOperator(const_cast<Expr*>(E), UO_AddrOf,
getContext().getPointerType(E->getType()),
SourceLocation());
}
}
}
}
if (BDRE->isByRef()) {
E = new (getContext())
UnaryOperator(const_cast<Expr*>(E), UO_AddrOf,
getContext().getPointerType(E->getType()),
SourceLocation());
}
RValue r = EmitAnyExpr(E, AggValueSlot::forAddr(Addr, false, true));
if (r.isScalar()) {
llvm::Value *Loc = r.getScalarVal();
const llvm::Type *Ty = Types[i+BlockFields];
if (BDRE->isByRef()) {
// E is now the address of the value field, instead, we want the
// address of the actual ByRef struct. We optimize this slightly
// compared to gcc by not grabbing the forwarding slot as this must
// be done during Block_copy for us, and we can postpone the work
// until then.
CharUnits offset = BlockDecls[BDRE->getDecl()];
llvm::Value *BlockLiteral = LoadBlockStruct();
Loc = Builder.CreateGEP(BlockLiteral,
llvm::ConstantInt::get(Int64Ty, offset.getQuantity()),
"block.literal");
Ty = llvm::PointerType::get(Ty, 0);
Loc = Builder.CreateBitCast(Loc, Ty);
Loc = Builder.CreateLoad(Loc);
// Loc = Builder.CreateBitCast(Loc, Ty);
}
Builder.CreateStore(Loc, 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.
}
NoteForHelper.resize(NumHelpers);
// __descriptor
llvm::Value *Descriptor = BuildDescriptorBlockDecl(BE, Info, Ty,
BlockVarLayout,
&NoteForHelper);
Descriptor = Builder.CreateBitCast(Descriptor, PtrToInt8Ty);
Builder.CreateStore(Descriptor, Builder.CreateStructGEP(V, 4, "block.tmp"));
}
QualType BPT = BE->getType();
V = Builder.CreateBitCast(V, ConvertType(BPT));
// See if this is a __weak block variable and the must call objc_read_weak
// on it.
const FunctionType *ftype = BPT->getPointeeType()->getAs<FunctionType>();
QualType RES = ftype->getResultType();
if (RES.isObjCGCWeak()) {
// Must cast argument to id*
const llvm::Type *ObjectPtrTy =
ConvertType(CGM.getContext().getObjCIdType());
const llvm::Type *PtrObjectPtrTy =
llvm::PointerType::getUnqual(ObjectPtrTy);
V = Builder.CreateBitCast(V, PtrObjectPtrTy);
V = CGM.getObjCRuntime().EmitObjCWeakRead(*this, V);
}
return V;
}
const llvm::Type *BlockModule::getBlockDescriptorType() {
if (BlockDescriptorType)
return BlockDescriptorType;
const llvm::Type *UnsignedLongTy =
getTypes().ConvertType(getContext().UnsignedLongTy);
// struct __block_descriptor {
// unsigned long reserved;
// unsigned long block_size;
//
// // later, the following will be added
//
// struct {
// void (*copyHelper)();
// void (*copyHelper)();
// } helpers; // !!! optional
//
// const char *signature; // the block signature
// const char *layout; // reserved
// };
BlockDescriptorType = llvm::StructType::get(UnsignedLongTy->getContext(),
UnsignedLongTy,
UnsignedLongTy,
NULL);
getModule().addTypeName("struct.__block_descriptor",
BlockDescriptorType);
return BlockDescriptorType;
}
const llvm::Type *BlockModule::getGenericBlockLiteralType() {
if (GenericBlockLiteralType)
return GenericBlockLiteralType;
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(IntTy->getContext(),
PtrToInt8Ty,
IntTy,
IntTy,
PtrToInt8Ty,
BlockDescPtrTy,
NULL);
getModule().addTypeName("struct.__block_literal_generic",
GenericBlockLiteralType);
return GenericBlockLiteralType;
}
RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr* E,
ReturnValueSlot ReturnValue) {
const BlockPointerType *BPT =
E->getCallee()->getType()->getAs<BlockPointerType>();
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");
BlockLiteral =
Builder.CreateBitCast(BlockLiteral,
llvm::Type::getInt8PtrTy(VMContext),
"tmp");
// Add the block literal.
QualType VoidPtrTy = getContext().getPointerType(getContext().VoidTy);
CallArgList Args;
Args.push_back(std::make_pair(RValue::get(BlockLiteral), VoidPtrTy));
QualType FnType = BPT->getPointeeType();
// And the rest of the arguments.
EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(),
E->arg_begin(), E->arg_end());
// Load the function.
llvm::Value *Func = Builder.CreateLoad(FuncPtr, "tmp");
const FunctionType *FuncTy = FnType->getAs<FunctionType>();
QualType ResultType = FuncTy->getResultType();
const CGFunctionInfo &FnInfo =
CGM.getTypes().getFunctionInfo(ResultType, Args,
FuncTy->getExtInfo());
// Cast the function pointer to the right type.
const llvm::Type *BlockFTy =
CGM.getTypes().GetFunctionType(FnInfo, false);
const llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
Func = Builder.CreateBitCast(Func, BlockFTyPtr);
// And call the block.
return EmitCall(FnInfo, Func, ReturnValue, Args);
}
void CodeGenFunction::AllocateBlockCXXThisPointer(const CXXThisExpr *E) {
assert(BlockCXXThisOffset.isZero() && "already computed 'this' pointer");
// Figure out what the offset is.
QualType T = E->getType();
std::pair<CharUnits,CharUnits> TypeInfo = getContext().getTypeInfoInChars(T);
CharUnits Offset = getBlockOffset(TypeInfo.first, TypeInfo.second);
BlockCXXThisOffset = Offset;
BlockLayout.push_back(E);
}
void CodeGenFunction::AllocateBlockDecl(const BlockDeclRefExpr *E) {
const ValueDecl *VD = E->getDecl();
CharUnits &Offset = BlockDecls[VD];
// See if we have already allocated an offset for this variable.
if (!Offset.isZero())
return;
// Don't run the expensive check, unless we have to.
if (!BlockHasCopyDispose)
if (E->isByRef()
|| BlockRequiresCopying(E->getType()))
BlockHasCopyDispose = true;
const ValueDecl *D = cast<ValueDecl>(E->getDecl());
CharUnits Size;
CharUnits Align;
if (E->isByRef()) {
llvm::tie(Size,Align) =
getContext().getTypeInfoInChars(getContext().VoidPtrTy);
} else {
Size = getContext().getTypeSizeInChars(D->getType());
Align = getContext().getDeclAlign(D);
}
Offset = getBlockOffset(Size, Align);
BlockLayout.push_back(E);
}
llvm::Value *CodeGenFunction::GetAddrOfBlockDecl(const ValueDecl *VD,
bool IsByRef) {
CharUnits offset = BlockDecls[VD];
assert(!offset.isZero() && "getting address of unallocated decl");
llvm::Value *BlockLiteral = LoadBlockStruct();
llvm::Value *V = Builder.CreateGEP(BlockLiteral,
llvm::ConstantInt::get(Int64Ty, offset.getQuantity()),
"block.literal");
if (IsByRef) {
const llvm::Type *PtrStructTy
= llvm::PointerType::get(BuildByRefType(VD), 0);
// The block literal will need a copy/destroy helper.
BlockHasCopyDispose = true;
const llvm::Type *Ty = PtrStructTy;
Ty = llvm::PointerType::get(Ty, 0);
V = Builder.CreateBitCast(V, Ty);
V = Builder.CreateLoad(V);
V = Builder.CreateStructGEP(V, 1, "forwarding");
V = Builder.CreateLoad(V);
V = Builder.CreateBitCast(V, PtrStructTy);
V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
VD->getNameAsString());
if (VD->getType()->isReferenceType())
V = Builder.CreateLoad(V);
} else {
const llvm::Type *Ty = CGM.getTypes().ConvertType(VD->getType());
Ty = llvm::PointerType::get(Ty, 0);
V = Builder.CreateBitCast(V, Ty);
if (VD->getType()->isReferenceType())
V = Builder.CreateLoad(V, "ref.tmp");
}
return V;
}
llvm::Constant *
BlockModule::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[4];
// Reserved
DescriptorFields[0] = llvm::Constant::getNullValue(UnsignedLongTy);
// Block literal size. For global blocks we just use the size of the generic
// block literal struct.
CharUnits BlockLiteralSize =
CGM.GetTargetTypeStoreSize(getGenericBlockLiteralType());
DescriptorFields[1] =
llvm::ConstantInt::get(UnsignedLongTy,BlockLiteralSize.getQuantity());
// signature. non-optional ObjC-style method descriptor @encode sequence
std::string BlockTypeEncoding;
CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
DescriptorFields[2] = llvm::ConstantExpr::getBitCast(
CGM.GetAddrOfConstantCString(BlockTypeEncoding), PtrToInt8Ty);
// layout
DescriptorFields[3] =
llvm::ConstantInt::get(UnsignedLongTy,0);
// build the structure from the 4 elements
llvm::Constant *DescriptorStruct =
llvm::ConstantStruct::get(VMContext, &DescriptorFields[0], 4, false);
llvm::GlobalVariable *Descriptor =
new llvm::GlobalVariable(getModule(), DescriptorStruct->getType(), true,
llvm::GlobalVariable::InternalLinkage,
DescriptorStruct, "__block_descriptor_global");
int FieldCount = 5;
// Generate the constants for the block literal.
std::vector<llvm::Constant*> LiteralFields(FieldCount);
CGBlockInfo Info(n);
llvm::Constant *BlockVarLayout;
llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap;
llvm::Function *Fn
= CodeGenFunction(CGM).GenerateBlockFunction(GlobalDecl(), BE,
Info, 0, BlockVarLayout,
LocalDeclMap);
assert(Info.BlockSize == BlockLiteralSize
&& "no imports allowed for global block");
// isa
LiteralFields[0] = CGM.getNSConcreteGlobalBlock();
// __flags
unsigned flags = computeBlockFlag(CGM, BE,
(BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE));
LiteralFields[1] =
llvm::ConstantInt::get(IntTy, flags);
// Reserved
LiteralFields[2] = llvm::Constant::getNullValue(IntTy);
// Function
LiteralFields[3] = Fn;
// Descriptor
LiteralFields[4] = Descriptor;
llvm::Constant *BlockLiteralStruct =
llvm::ConstantStruct::get(VMContext, LiteralFields, false);
llvm::GlobalVariable *BlockLiteral =
new llvm::GlobalVariable(getModule(), BlockLiteralStruct->getType(), true,
llvm::GlobalVariable::InternalLinkage,
BlockLiteralStruct, "__block_literal_global");
return BlockLiteral;
}
llvm::Value *CodeGenFunction::LoadBlockStruct() {
llvm::Value *V = Builder.CreateLoad(LocalDeclMap[getBlockStructDecl()],
"self");
// For now, we codegen based upon byte offsets.
return Builder.CreateBitCast(V, PtrToInt8Ty);
}
llvm::Function *
CodeGenFunction::GenerateBlockFunction(GlobalDecl GD, const BlockExpr *BExpr,
CGBlockInfo &Info,
const Decl *OuterFuncDecl,
llvm::Constant *& BlockVarLayout,
llvm::DenseMap<const Decl*, llvm::Value*> ldm) {
// Check if we should generate debug info for this block.
if (CGM.getDebugInfo())
DebugInfo = CGM.getDebugInfo();
// Arrange for local static and local extern declarations to appear
// to be local to this function as well, as they are directly referenced
// in a block.
for (llvm::DenseMap<const Decl *, llvm::Value*>::iterator i = ldm.begin();
i != ldm.end();
++i) {
const VarDecl *VD = dyn_cast<VarDecl>(i->first);
if (VD->getStorageClass() == SC_Static || VD->hasExternalStorage())
LocalDeclMap[VD] = i->second;
}
BlockOffset =
CGM.GetTargetTypeStoreSize(CGM.getGenericBlockLiteralType());
BlockAlign = getContext().getTypeAlignInChars(getContext().VoidPtrTy);
const FunctionType *BlockFunctionType = BExpr->getFunctionType();
QualType ResultType;
FunctionType::ExtInfo EInfo = getFunctionExtInfo(*BlockFunctionType);
bool IsVariadic;
if (const FunctionProtoType *FTy =
dyn_cast<FunctionProtoType>(BlockFunctionType)) {
ResultType = FTy->getResultType();
IsVariadic = FTy->isVariadic();
} else {
// K&R style block.
ResultType = BlockFunctionType->getResultType();
IsVariadic = false;
}
FunctionArgList Args;
CurFuncDecl = OuterFuncDecl;
const BlockDecl *BD = BExpr->getBlockDecl();
IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
// Build the block struct now.
AllocateAllBlockDeclRefs(*this, Info);
// Capture block layout info. here.
if (CGM.getContext().getLangOptions().ObjC1)
BlockVarLayout = CGM.getObjCRuntime().GCBlockLayout(*this, BlockLayout);
else
BlockVarLayout = llvm::Constant::getNullValue(PtrToInt8Ty);
QualType ParmTy = getContext().getBlockParmType(BlockHasCopyDispose,
BlockLayout);
// FIXME: This leaks
ImplicitParamDecl *SelfDecl =
ImplicitParamDecl::Create(getContext(), const_cast<BlockDecl*>(BD),
SourceLocation(), II,
ParmTy);
Args.push_back(std::make_pair(SelfDecl, SelfDecl->getType()));
BlockStructDecl = SelfDecl;
for (BlockDecl::param_const_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(ResultType, Args, EInfo);
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *LTy = Types.GetFunctionType(FI, IsVariadic);
MangleBuffer Name;
CGM.getMangledName(GD, Name, BD);
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
Name.getString(), &CGM.getModule());
CGM.SetInternalFunctionAttributes(BD, Fn, FI);
StartFunction(BD, ResultType, Fn, Args,
BExpr->getBody()->getLocEnd());
CurFuncDecl = OuterFuncDecl;
QualType FnType(BlockFunctionType, 0);
bool HasPrototype = isa<FunctionProtoType>(BlockFunctionType);
IdentifierInfo *ID = &getContext().Idents.get(Name.getString());
CurCodeDecl = FunctionDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(), ID, FnType,
0,
SC_Static,
SC_None,
false, HasPrototype);
if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(FnType)) {
const FunctionDecl *CFD = dyn_cast<FunctionDecl>(CurCodeDecl);
FunctionDecl *FD = const_cast<FunctionDecl *>(CFD);
llvm::SmallVector<ParmVarDecl*, 16> Params;
for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i)
Params.push_back(ParmVarDecl::Create(getContext(), FD,
SourceLocation(), 0,
FT->getArgType(i), /*TInfo=*/0,
SC_None, SC_None, 0));
FD->setParams(Params.data(), Params.size());
}
// If we have a C++ 'this' reference, go ahead and force it into
// existence now.
if (Info.CXXThisRef) {
assert(!BlockCXXThisOffset.isZero() &&
"haven't yet allocated 'this' reference");
// TODO: I have a dream that one day this will be typed.
llvm::Value *BlockLiteral = LoadBlockStruct();
llvm::Value *ThisPtrRaw =
Builder.CreateConstInBoundsGEP1_64(BlockLiteral,
BlockCXXThisOffset.getQuantity(),
"this.ptr.raw");
const llvm::Type *Ty =
CGM.getTypes().ConvertType(Info.CXXThisRef->getType());
Ty = llvm::PointerType::get(Ty, 0);
llvm::Value *ThisPtr = Builder.CreateBitCast(ThisPtrRaw, Ty, "this.ptr");
CXXThisValue = Builder.CreateLoad(ThisPtr, "this");
}
// If we have an Objective C 'self' reference, go ahead and force it
// into existence now.
if (Info.NeedsObjCSelf) {
ValueDecl *Self = cast<ObjCMethodDecl>(CurFuncDecl)->getSelfDecl();
LocalDeclMap[Self] = GetAddrOfBlockDecl(Self, false);
}
// Save a spot to insert the debug information for all the BlockDeclRefDecls.
llvm::BasicBlock *entry = Builder.GetInsertBlock();
llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
--entry_ptr;
EmitStmt(BExpr->getBody());
// Remember where we were...
llvm::BasicBlock *resume = Builder.GetInsertBlock();
// Go back to the entry.
++entry_ptr;
Builder.SetInsertPoint(entry, entry_ptr);
if (CGDebugInfo *DI = getDebugInfo()) {
// Emit debug information for all the BlockDeclRefDecls.
// FIXME: also for 'this'
for (unsigned i = 0, e = BlockLayout.size(); i != e; ++i) {
if (const BlockDeclRefExpr *BDRE =
dyn_cast<BlockDeclRefExpr>(BlockLayout[i])) {
const ValueDecl *D = BDRE->getDecl();
DI->setLocation(D->getLocation());
DI->EmitDeclareOfBlockDeclRefVariable(BDRE,
LocalDeclMap[getBlockStructDecl()],
Builder, this);
}
}
}
// And resume where we left off.
if (resume == 0)
Builder.ClearInsertionPoint();
else
Builder.SetInsertPoint(resume);
FinishFunction(cast<CompoundStmt>(BExpr->getBody())->getRBracLoc());
// The runtime needs a minimum alignment of a void *.
CharUnits MinAlign = getContext().getTypeAlignInChars(getContext().VoidPtrTy);
BlockOffset = CharUnits::fromQuantity(
llvm::RoundUpToAlignment(BlockOffset.getQuantity(),
MinAlign.getQuantity()));
Info.BlockSize = BlockOffset;
Info.BlockAlign = BlockAlign;
Info.BlockLayout = BlockLayout;
Info.BlockHasCopyDispose = BlockHasCopyDispose;
return Fn;
}
CharUnits BlockFunction::getBlockOffset(CharUnits Size, CharUnits Align) {
assert((Align.isPositive()) && "alignment must be 1 byte or more");
CharUnits OldOffset = BlockOffset;
// Ensure proper alignment, even if it means we have to have a gap
BlockOffset = CharUnits::fromQuantity(
llvm::RoundUpToAlignment(BlockOffset.getQuantity(), Align.getQuantity()));
BlockAlign = std::max(Align, BlockAlign);
CharUnits Pad = BlockOffset - OldOffset;
if (Pad.isPositive()) {
QualType PadTy = getContext().getConstantArrayType(getContext().CharTy,
llvm::APInt(32,
Pad.getQuantity()),
ArrayType::Normal, 0);
ValueDecl *PadDecl = VarDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(),
0, QualType(PadTy), 0,
SC_None, SC_None);
Expr *E = new (getContext()) DeclRefExpr(PadDecl, PadDecl->getType(),
SourceLocation());
BlockLayout.push_back(E);
}
BlockOffset += Size;
return BlockOffset - Size;
}
llvm::Constant *BlockFunction::
GenerateCopyHelperFunction(bool BlockHasCopyDispose, const llvm::StructType *T,
std::vector<HelperInfo> *NoteForHelperp) {
QualType R = getContext().VoidTy;
FunctionArgList Args;
// FIXME: This leaks
ImplicitParamDecl *Dst =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(Dst, Dst->getType()));
ImplicitParamDecl *Src =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(Src, Src->getType()));
const CGFunctionInfo &FI =
CGM.getTypes().getFunctionInfo(R, Args, FunctionType::ExtInfo());
// FIXME: We'd like to put these into a mergable by content, with
// internal linkage.
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
"__copy_helper_block_", &CGM.getModule());
IdentifierInfo *II
= &CGM.getContext().Idents.get("__copy_helper_block_");
FunctionDecl *FD = FunctionDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(), II, R, 0,
SC_Static,
SC_None,
false,
true);
CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
llvm::Value *SrcObj = CGF.GetAddrOfLocalVar(Src);
llvm::Type *PtrPtrT;
if (NoteForHelperp) {
std::vector<HelperInfo> &NoteForHelper = *NoteForHelperp;
PtrPtrT = llvm::PointerType::get(llvm::PointerType::get(T, 0), 0);
SrcObj = Builder.CreateBitCast(SrcObj, PtrPtrT);
SrcObj = Builder.CreateLoad(SrcObj);
llvm::Value *DstObj = CGF.GetAddrOfLocalVar(Dst);
llvm::Type *PtrPtrT;
PtrPtrT = llvm::PointerType::get(llvm::PointerType::get(T, 0), 0);
DstObj = Builder.CreateBitCast(DstObj, PtrPtrT);
DstObj = Builder.CreateLoad(DstObj);
for (unsigned i=0; i < NoteForHelper.size(); ++i) {
int flag = NoteForHelper[i].flag;
int index = NoteForHelper[i].index;
if ((NoteForHelper[i].flag & BLOCK_FIELD_IS_BYREF)
|| NoteForHelper[i].RequiresCopying) {
llvm::Value *Srcv = SrcObj;
Srcv = Builder.CreateStructGEP(Srcv, index);
Srcv = Builder.CreateBitCast(Srcv,
llvm::PointerType::get(PtrToInt8Ty, 0));
Srcv = Builder.CreateLoad(Srcv);
llvm::Value *Dstv = Builder.CreateStructGEP(DstObj, index);
Dstv = Builder.CreateBitCast(Dstv, PtrToInt8Ty);
llvm::Value *N = llvm::ConstantInt::get(CGF.Int32Ty, flag);
llvm::Value *F = CGM.getBlockObjectAssign();
Builder.CreateCall3(F, Dstv, Srcv, N);
}
}
}
CGF.FinishFunction();
return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
}
llvm::Constant *BlockFunction::
GenerateDestroyHelperFunction(bool BlockHasCopyDispose,
const llvm::StructType* T,
std::vector<HelperInfo> *NoteForHelperp) {
QualType R = getContext().VoidTy;
FunctionArgList Args;
// FIXME: This leaks
ImplicitParamDecl *Src =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(Src, Src->getType()));
const CGFunctionInfo &FI =
CGM.getTypes().getFunctionInfo(R, Args, FunctionType::ExtInfo());
// FIXME: We'd like to put these into a mergable by content, with
// internal linkage.
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
"__destroy_helper_block_", &CGM.getModule());
IdentifierInfo *II
= &CGM.getContext().Idents.get("__destroy_helper_block_");
FunctionDecl *FD = FunctionDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(), II, R, 0,
SC_Static,
SC_None,
false, true);
CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
if (NoteForHelperp) {
std::vector<HelperInfo> &NoteForHelper = *NoteForHelperp;
llvm::Value *SrcObj = CGF.GetAddrOfLocalVar(Src);
llvm::Type *PtrPtrT;
PtrPtrT = llvm::PointerType::get(llvm::PointerType::get(T, 0), 0);
SrcObj = Builder.CreateBitCast(SrcObj, PtrPtrT);
SrcObj = Builder.CreateLoad(SrcObj);
for (unsigned i=0; i < NoteForHelper.size(); ++i) {
int flag = NoteForHelper[i].flag;
int index = NoteForHelper[i].index;
if ((NoteForHelper[i].flag & BLOCK_FIELD_IS_BYREF)
|| NoteForHelper[i].RequiresCopying) {
llvm::Value *Srcv = SrcObj;
Srcv = Builder.CreateStructGEP(Srcv, index);
Srcv = Builder.CreateBitCast(Srcv,
llvm::PointerType::get(PtrToInt8Ty, 0));
Srcv = Builder.CreateLoad(Srcv);
BuildBlockRelease(Srcv, flag);
}
}
}
CGF.FinishFunction();
return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
}
llvm::Constant *BlockFunction::BuildCopyHelper(const llvm::StructType *T,
std::vector<HelperInfo> *NoteForHelper) {
return CodeGenFunction(CGM).GenerateCopyHelperFunction(BlockHasCopyDispose,
T, NoteForHelper);
}
llvm::Constant *BlockFunction::BuildDestroyHelper(const llvm::StructType *T,
std::vector<HelperInfo> *NoteForHelperp) {
return CodeGenFunction(CGM).GenerateDestroyHelperFunction(BlockHasCopyDispose,
T, NoteForHelperp);
}
llvm::Constant *BlockFunction::
GeneratebyrefCopyHelperFunction(const llvm::Type *T, int flag) {
QualType R = getContext().VoidTy;
FunctionArgList Args;
// FIXME: This leaks
ImplicitParamDecl *Dst =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(Dst, Dst->getType()));
// FIXME: This leaks
ImplicitParamDecl *Src =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(Src, Src->getType()));
const CGFunctionInfo &FI =
CGM.getTypes().getFunctionInfo(R, Args, FunctionType::ExtInfo());
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
// FIXME: We'd like to put these into a mergable by content, with
// internal linkage.
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
"__Block_byref_id_object_copy_", &CGM.getModule());
IdentifierInfo *II
= &CGM.getContext().Idents.get("__Block_byref_id_object_copy_");
FunctionDecl *FD = FunctionDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(), II, R, 0,
SC_Static,
SC_None,
false, true);
CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
// dst->x
llvm::Value *V = CGF.GetAddrOfLocalVar(Dst);
V = Builder.CreateBitCast(V, llvm::PointerType::get(T, 0));
V = Builder.CreateLoad(V);
V = Builder.CreateStructGEP(V, 6, "x");
llvm::Value *DstObj = Builder.CreateBitCast(V, PtrToInt8Ty);
// src->x
V = CGF.GetAddrOfLocalVar(Src);
V = Builder.CreateLoad(V);
V = Builder.CreateBitCast(V, T);
V = Builder.CreateStructGEP(V, 6, "x");
V = Builder.CreateBitCast(V, llvm::PointerType::get(PtrToInt8Ty, 0));
llvm::Value *SrcObj = Builder.CreateLoad(V);
flag |= BLOCK_BYREF_CALLER;
llvm::Value *N = llvm::ConstantInt::get(CGF.Int32Ty, flag);
llvm::Value *F = CGM.getBlockObjectAssign();
Builder.CreateCall3(F, DstObj, SrcObj, N);
CGF.FinishFunction();
return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
}
llvm::Constant *
BlockFunction::GeneratebyrefDestroyHelperFunction(const llvm::Type *T,
int flag) {
QualType R = getContext().VoidTy;
FunctionArgList Args;
// FIXME: This leaks
ImplicitParamDecl *Src =
ImplicitParamDecl::Create(getContext(), 0,
SourceLocation(), 0,
getContext().getPointerType(getContext().VoidTy));
Args.push_back(std::make_pair(Src, Src->getType()));
const CGFunctionInfo &FI =
CGM.getTypes().getFunctionInfo(R, Args, FunctionType::ExtInfo());
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
// FIXME: We'd like to put these into a mergable by content, with
// internal linkage.
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
"__Block_byref_id_object_dispose_",
&CGM.getModule());
IdentifierInfo *II
= &CGM.getContext().Idents.get("__Block_byref_id_object_dispose_");
FunctionDecl *FD = FunctionDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(), II, R, 0,
SC_Static,
SC_None,
false, true);
CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
llvm::Value *V = CGF.GetAddrOfLocalVar(Src);
V = Builder.CreateBitCast(V, llvm::PointerType::get(T, 0));
V = Builder.CreateLoad(V);
V = Builder.CreateStructGEP(V, 6, "x");
V = Builder.CreateBitCast(V, llvm::PointerType::get(PtrToInt8Ty, 0));
V = Builder.CreateLoad(V);
flag |= BLOCK_BYREF_CALLER;
BuildBlockRelease(V, flag);
CGF.FinishFunction();
return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
}
llvm::Constant *BlockFunction::BuildbyrefCopyHelper(const llvm::Type *T,
int Flag, unsigned Align) {
// All alignments below that of pointer alignment collapse down to just
// pointer alignment, as we always have at least that much alignment to begin
// with.
Align /= unsigned(CGF.Target.getPointerAlign(0)/8);
// As an optimization, we only generate a single function of each kind we
// might need. We need a different one for each alignment and for each
// setting of flags. We mix Align and flag to get the kind.
uint64_t Kind = (uint64_t)Align*BLOCK_BYREF_CURRENT_MAX + Flag;
llvm::Constant *&Entry = CGM.AssignCache[Kind];
if (Entry)
return Entry;
return Entry = CodeGenFunction(CGM).GeneratebyrefCopyHelperFunction(T, Flag);
}
llvm::Constant *BlockFunction::BuildbyrefDestroyHelper(const llvm::Type *T,
int Flag,
unsigned Align) {
// All alignments below that of pointer alignment collpase down to just
// pointer alignment, as we always have at least that much alignment to begin
// with.
Align /= unsigned(CGF.Target.getPointerAlign(0)/8);
// As an optimization, we only generate a single function of each kind we
// might need. We need a different one for each alignment and for each
// setting of flags. We mix Align and flag to get the kind.
uint64_t Kind = (uint64_t)Align*BLOCK_BYREF_CURRENT_MAX + Flag;
llvm::Constant *&Entry = CGM.DestroyCache[Kind];
if (Entry)
return Entry;
return Entry=CodeGenFunction(CGM).GeneratebyrefDestroyHelperFunction(T, Flag);
}
void BlockFunction::BuildBlockRelease(llvm::Value *V, int flag) {
llvm::Value *F = CGM.getBlockObjectDispose();
llvm::Value *N;
V = Builder.CreateBitCast(V, PtrToInt8Ty);
N = llvm::ConstantInt::get(CGF.Int32Ty, flag);
Builder.CreateCall2(F, V, N);
}
ASTContext &BlockFunction::getContext() const { return CGM.getContext(); }
BlockFunction::BlockFunction(CodeGenModule &cgm, CodeGenFunction &cgf,
CGBuilderTy &B)
: CGM(cgm), VMContext(cgm.getLLVMContext()), CGF(cgf), Builder(B) {
PtrToInt8Ty = llvm::PointerType::getUnqual(
llvm::Type::getInt8Ty(VMContext));
BlockHasCopyDispose = false;
}
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