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emit aliases as the definitions fly by, don't bother deferring until 

the end of the module.

llvm-svn: 67482
This commit is contained in:
Chris Lattner 2009-03-22 21:47:11 +00:00
parent 827a3552a4
commit 5404169327
2 changed files with 64 additions and 82 deletions
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139
clang/lib/CodeGen/CodeGenModule.cpp
View File

@ -57,7 +57,6 @@ CodeGenModule::~CodeGenModule() {
}
void CodeGenModule::Release() {
EmitAliases();
EmitDeferred();
if (Runtime)
if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction())
@ -324,75 +323,6 @@ void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD,
FD->isInline(), F, false);
}
void CodeGenModule::EmitAliases() {
for (unsigned i = 0, e = Aliases.size(); i != e; ++i) {
const ValueDecl *D = Aliases[i];
const AliasAttr *AA = D->getAttr<AliasAttr>();
// This is something of a hack, if the FunctionDecl got overridden
// then its attributes will be moved to the new declaration. In
// this case the current decl has no alias attribute, but we will
// eventually see it.
if (!AA)
continue;
const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
// Unique the name through the identifier table.
const char *AliaseeName = AA->getAliasee().c_str();
AliaseeName = getContext().Idents.get(AliaseeName).getName();
// Create a reference to the named value. This ensures that it is emitted
// if a deferred decl.
llvm::Constant *Aliasee;
if (isa<llvm::FunctionType>(DeclTy))
Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, 0);
else
Aliasee = GetOrCreateLLVMGlobal(AliaseeName,
llvm::PointerType::getUnqual(DeclTy), 0);
// Create the new alias itself, but don't set a name yet.
llvm::GlobalValue *GA =
new llvm::GlobalAlias(Aliasee->getType(),
llvm::Function::ExternalLinkage,
"", Aliasee, &getModule());
// See if there is already something with the alias' name in the module.
const char *MangledName = getMangledName(D);
llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
if (Entry && !Entry->isDeclaration()) {
// If there is a definition in the module, then it wins over the alias.
// This is dubious, but allow it to be safe. Just ignore the alias.
delete GA;
continue;
}
if (Entry) {
// If there is a declaration in the module, then we had an extern followed
// by the alias, as in:
// extern int test6();
// ...
// int test6() __attribute__((alias("test7")));
//
// Remove it and replace uses of it with the alias.
Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
Entry->getType()));
// FIXME: What if it was attribute used? Dangling pointer from LLVMUsed.
Entry->eraseFromParent();
}
// Now we know that there is no conflict, set the name.
Entry = GA;
GA->setName(MangledName);
// Alias should never be internal or inline.
SetGlobalValueAttributes(D, false, false, GA, true);
}
}
void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
assert(!GV->isDeclaration() &&
"Only globals with definition can force usage.");
@ -509,12 +439,10 @@ bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
}
void CodeGenModule::EmitGlobal(const ValueDecl *Global) {
// Aliases are deferred until code for everything else has been
// emitted.
if (Global->getAttr<AliasAttr>()) {
Aliases.push_back(Global);
return;
}
// If this is an alias definition (which otherwise looks like a declaration)
// emit it now.
if (Global->getAttr<AliasAttr>())
return EmitAliasDefinition(Global);
// Ignore declarations, they will be emitted on their first use.
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
@ -936,6 +864,65 @@ void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) {
AddGlobalDtor(Fn, DA->getPriority());
}
void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) {
const AliasAttr *AA = D->getAttr<AliasAttr>();
assert(AA && "Not an alias?");
const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
// Unique the name through the identifier table.
const char *AliaseeName = AA->getAliasee().c_str();
AliaseeName = getContext().Idents.get(AliaseeName).getName();
// Create a reference to the named value. This ensures that it is emitted
// if a deferred decl.
llvm::Constant *Aliasee;
if (isa<llvm::FunctionType>(DeclTy))
Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, 0);
else
Aliasee = GetOrCreateLLVMGlobal(AliaseeName,
llvm::PointerType::getUnqual(DeclTy), 0);
// Create the new alias itself, but don't set a name yet.
llvm::GlobalValue *GA =
new llvm::GlobalAlias(Aliasee->getType(),
llvm::Function::ExternalLinkage,
"", Aliasee, &getModule());
// See if there is already something with the alias' name in the module.
const char *MangledName = getMangledName(D);
llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
if (Entry && !Entry->isDeclaration()) {
// If there is a definition in the module, then it wins over the alias.
// This is dubious, but allow it to be safe. Just ignore the alias.
GA->eraseFromParent();
return;
}
if (Entry) {
// If there is a declaration in the module, then we had an extern followed
// by the alias, as in:
// extern int test6();
// ...
// int test6() __attribute__((alias("test7")));
//
// Remove it and replace uses of it with the alias.
Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
Entry->getType()));
// FIXME: What if it was attribute used? Dangling pointer from LLVMUsed.
Entry->eraseFromParent();
}
// Now we know that there is no conflict, set the name.
Entry = GA;
GA->setName(MangledName);
// Alias should never be internal or inline.
SetGlobalValueAttributes(D, false, false, GA, true);
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);

7
clang/lib/CodeGen/CodeGenModule.h
View File

@ -104,11 +104,6 @@ class CodeGenModule : public BlockModule {
/// has one).
llvm::StringSet<> MangledNames;
/// Aliases - List of aliases in module. These cannot be emitted until all the
/// code has been seen, as they reference things by name instead of directly
/// and may reference forward.
std::vector<const ValueDecl*> Aliases;
/// DeferredDecls - This contains all the decls which have definitions but
/// which are deferred for emission and therefore should only be output if
/// they are actually used. If a decl is in this, then it is known to have
@ -331,6 +326,7 @@ private:
void EmitGlobalFunctionDefinition(const FunctionDecl *D);
void EmitGlobalVarDefinition(const VarDecl *D);
void EmitAliasDefinition(const ValueDecl *D);
void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);
// FIXME: Hardcoding priority here is gross.
@ -342,7 +338,6 @@ private:
/// suitable for use as a LLVM constructor or destructor array.
void EmitCtorList(const CtorList &Fns, const char *GlobalName);
void EmitAliases(void);
void EmitAnnotations(void);
/// EmitDeferred - Emit any needed decls for which code generation