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//===--- CGDecl.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 Decl nodes as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CGDebugInfo.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Type.h"
#include "llvm/Support/Dwarf.h"
using namespace clang;
using namespace CodeGen;
void CodeGenFunction::EmitDecl(const Decl &D) {
switch (D.getKind()) {
default: assert(0 && "Unknown decl kind!");
case Decl::ParmVar:
assert(0 && "Parmdecls should not be in declstmts!");
case Decl::Typedef: // typedef int X;
case Decl::Function: // void X();
case Decl::Record: // struct/union/class X;
case Decl::Enum: // enum X;
case Decl::EnumConstant: // enum ? { X = ? }
case Decl::CXXRecord: // struct/union/class X; [C++]
// None of these decls require codegen support.
return;
case Decl::Var: {
const VarDecl &VD = cast<VarDecl>(D);
assert(VD.isBlockVarDecl() &&
"Should not see file-scope variables inside a function!");
return EmitBlockVarDecl(VD);
}
}
}
/// EmitBlockVarDecl - This method handles emission of any variable declaration
/// inside a function, including static vars etc.
void CodeGenFunction::EmitBlockVarDecl(const VarDecl &D) {
switch (D.getStorageClass()) {
case VarDecl::Static:
return EmitStaticBlockVarDecl(D);
case VarDecl::Extern:
// Don't emit it now, allow it to be emitted lazily on its first use.
return;
default:
assert((D.getStorageClass() == VarDecl::None ||
D.getStorageClass() == VarDecl::Auto ||
D.getStorageClass() == VarDecl::Register) &&
"Unknown storage class");
return EmitLocalBlockVarDecl(D);
}
}
llvm::GlobalValue *
CodeGenFunction::GenerateStaticBlockVarDecl(const VarDecl &D,
bool NoInit,
const char *Separator) {
QualType Ty = D.getType();
assert(Ty->isConstantSizeType() && "VLAs can't be static");
const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
llvm::Constant *Init = 0;
if ((D.getInit() == 0) || NoInit) {
Init = llvm::Constant::getNullValue(LTy);
} else {
if (D.getInit()->isConstantExpr(getContext(), 0))
Init = CGM.EmitConstantExpr(D.getInit(), this);
else {
assert(getContext().getLangOptions().CPlusPlus &&
"only C++ supports non-constant static initializers!");
return GenerateStaticCXXBlockVarDecl(D);
}
}
assert(Init && "Unable to create initialiser for static decl");
std::string ContextName;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurFuncDecl))
ContextName = FD->getName();
else if (isa<ObjCMethodDecl>(CurFuncDecl))
ContextName = std::string(CurFn->getNameStart(),
CurFn->getNameStart() + CurFn->getNameLen());
else
assert(0 && "Unknown context for block var decl");
llvm::GlobalValue *GV =
new llvm::GlobalVariable(Init->getType(), false,
llvm::GlobalValue::InternalLinkage,
Init, ContextName + Separator + D.getName(),
&CGM.getModule(), 0, Ty.getAddressSpace());
return GV;
}
void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) {
llvm::Value *&DMEntry = LocalDeclMap[&D];
assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
llvm::GlobalValue *GV = GenerateStaticBlockVarDecl(D, false, ".");
if (const AnnotateAttr *AA = D.getAttr<AnnotateAttr>()) {
SourceManager &SM = CGM.getContext().getSourceManager();
llvm::Constant *Ann =
CGM.EmitAnnotateAttr(GV, AA, SM.getLogicalLineNumber(D.getLocation()));
CGM.AddAnnotation(Ann);
}
const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
const llvm::Type *LPtrTy =
llvm::PointerType::get(LTy, D.getType().getAddressSpace());
DMEntry = llvm::ConstantExpr::getBitCast(GV, LPtrTy);
// Emit global variable debug descriptor for static vars.
CGDebugInfo *DI = CGM.getDebugInfo();
if(DI) {
if(D.getLocation().isValid())
DI->setLocation(D.getLocation());
DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D);
}
}
/// EmitLocalBlockVarDecl - Emit code and set up an entry in LocalDeclMap for a
/// variable declaration with auto, register, or no storage class specifier.
/// These turn into simple stack objects, or GlobalValues depending on target.
void CodeGenFunction::EmitLocalBlockVarDecl(const VarDecl &D) {
QualType Ty = D.getType();
llvm::Value *DeclPtr;
if (Ty->isConstantSizeType()) {
if (!Target.useGlobalsForAutomaticVariables()) {
// A normal fixed sized variable becomes an alloca in the entry block.
const llvm::Type *LTy = ConvertType(Ty);
llvm::AllocaInst * Alloc = CreateTempAlloca(LTy, D.getName());
unsigned align = getContext().getTypeAlign(Ty);
if (const AlignedAttr* AA = D.getAttr<AlignedAttr>())
align = std::max(align, AA->getAlignment());
Alloc->setAlignment(align >> 3);
DeclPtr = Alloc;
} else {
// Targets that don't support recursion emit locals as globals.
const char *Class =
D.getStorageClass() == VarDecl::Register ? ".reg." : ".auto.";
DeclPtr = GenerateStaticBlockVarDecl(D, true, Class);
}
} else {
CGM.ErrorUnsupported(&D, "variable-length array");
// FIXME: VLA: Add VLA support. For now just make up enough to let
// the compile go through.
const llvm::Type *LTy = ConvertType(Ty);
llvm::AllocaInst * Alloc = CreateTempAlloca(LTy, D.getName());
DeclPtr = Alloc;
}
llvm::Value *&DMEntry = LocalDeclMap[&D];
assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
DMEntry = DeclPtr;
// Emit debug info for local var declaration.
CGDebugInfo *DI = CGM.getDebugInfo();
if(DI) {
if(D.getLocation().isValid())
DI->setLocation(D.getLocation());
DI->EmitDeclare(&D, llvm::dwarf::DW_TAG_auto_variable,
DeclPtr, Builder);
}
// If this local has an initializer, emit it now.
if (const Expr *Init = D.getInit()) {
if (!hasAggregateLLVMType(Init->getType())) {
llvm::Value *V = EmitScalarExpr(Init);
Builder.CreateStore(V, DeclPtr, D.getType().isVolatileQualified());
} else if (Init->getType()->isAnyComplexType()) {
EmitComplexExprIntoAddr(Init, DeclPtr, D.getType().isVolatileQualified());
} else {
EmitAggExpr(Init, DeclPtr, D.getType().isVolatileQualified());
}
}
}
/// Emit an alloca (or GlobalValue depending on target)
/// for the specified parameter and set up LocalDeclMap.
void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg) {
// FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
assert(isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D) &&
"Invalid argument to EmitParmDecl");
QualType Ty = D.getType();
llvm::Value *DeclPtr;
if (!Ty->isConstantSizeType()) {
// Variable sized values always are passed by-reference.
DeclPtr = Arg;
} else if (Target.useGlobalsForAutomaticVariables()) {
DeclPtr = GenerateStaticBlockVarDecl(D, true, ".arg.");
} else {
// A fixed sized single-value variable becomes an alloca in the entry block.
const llvm::Type *LTy = ConvertType(Ty);
if (LTy->isSingleValueType()) {
// TODO: Alignment
std::string Name(D.getName());
Name += ".addr";
DeclPtr = CreateTempAlloca(LTy, Name.c_str());
// Store the initial value into the alloca.
Builder.CreateStore(Arg, DeclPtr,Ty.isVolatileQualified());
} else {
// Otherwise, if this is an aggregate, just use the input pointer.
DeclPtr = Arg;
}
Arg->setName(D.getName());
}
llvm::Value *&DMEntry = LocalDeclMap[&D];
assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
DMEntry = DeclPtr;
// Emit debug info for param declaration.
CGDebugInfo *DI = CGM.getDebugInfo();
if
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