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Change CodeGenModule to rely on the Module's symbol table instead of

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shadowing it in the GlobalDeclMap.  Eliminates the string-uniquing
requirement for mangled names, which should help C++ codegen times a little.
Forces us to do string lookups instead of pointer lookups, which might hurt
codegen times a little across the board.  We'll see how it plays out.

Removing the string-uniquing requirement implicitly fixes any bugs like
PR6635 which arose from the fact that we had multiple uniquing tables for
different kinds of identifiers.

llvm-svn: 99012
This commit is contained in:
John McCall
2010-03-19 23:29:14 +00:00
parent 3e2bb702db
commit 7ec5043c2c
7 changed files with 164 additions and 172 deletions
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158
clang/lib/CodeGen/CodeGenModule.cpp
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@@ -163,15 +163,15 @@ void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
}
}
const char *CodeGenModule::getMangledName(const GlobalDecl &GD) {
void CodeGenModule::getMangledName(MangleBuffer &Buffer, GlobalDecl GD) {
const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND))
return getMangledCXXCtorName(D, GD.getCtorType());
return getMangledCXXCtorName(Buffer, D, GD.getCtorType());
if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND))
return getMangledCXXDtorName(D, GD.getDtorType());
return getMangledCXXDtorName(Buffer, D, GD.getDtorType());
return getMangledName(ND);
return getMangledName(Buffer, ND);
}
/// \brief Retrieves the mangled name for the given declaration.
@@ -180,23 +180,19 @@ const char *CodeGenModule::getMangledName(const GlobalDecl &GD) {
/// const char* containing the mangled name. Otherwise, returns
/// the unmangled name.
///
const char *CodeGenModule::getMangledName(const NamedDecl *ND) {
void CodeGenModule::getMangledName(MangleBuffer &Buffer,
const NamedDecl *ND) {
if (!getMangleContext().shouldMangleDeclName(ND)) {
assert(ND->getIdentifier() && "Attempt to mangle unnamed decl.");
return ND->getNameAsCString();
Buffer.setString(ND->getNameAsCString());
return;
}
llvm::SmallString<256> Name;
getMangleContext().mangleName(ND, Name);
Name += '\0';
return UniqueMangledName(Name.begin(), Name.end());
getMangleContext().mangleName(ND, Buffer.getBuffer());
}
const char *CodeGenModule::UniqueMangledName(const char *NameStart,
const char *NameEnd) {
assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!");
return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData();
llvm::GlobalValue *CodeGenModule::GetGlobalValue(llvm::StringRef Name) {
return getModule().getNamedValue(Name);
}
/// AddGlobalCtor - Add a function to the list that will be called before
@@ -505,11 +501,12 @@ void CodeGenModule::EmitDeferred() {
GlobalDecl D = DeferredDeclsToEmit.back();
DeferredDeclsToEmit.pop_back();
// The mangled name for the decl must have been emitted in GlobalDeclMap.
// Look it up to see if it was defined with a stronger definition (e.g. an
// extern inline function with a strong function redefinition). If so,
// just ignore the deferred decl.
llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)];
MangleBuffer Name;
getMangledName(Name, D);
llvm::GlobalValue *CGRef = GetGlobalValue(Name);
assert(CGRef && "Deferred decl wasn't referenced?");
if (!CGRef->isDeclaration())
@@ -644,18 +641,14 @@ llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
// Unique the name through the identifier table.
const char *AliaseeName =
getContext().Idents.get(AA->getAliasee()).getNameStart();
// See if there is already something with the target's name in the module.
llvm::GlobalValue *Entry = GlobalDeclMap[AliaseeName];
llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
llvm::Constant *Aliasee;
if (isa<llvm::FunctionType>(DeclTy))
Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl());
Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl());
else
Aliasee = GetOrCreateLLVMGlobal(AliaseeName,
Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy), 0);
if (!Entry) {
llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee);
@@ -676,7 +669,7 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
// If this is an alias definition (which otherwise looks like a declaration)
// emit it now.
if (Global->hasAttr<AliasAttr>())
return EmitAliasDefinition(Global);
return EmitAliasDefinition(GD);
// Ignore declarations, they will be emitted on their first use.
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
@@ -696,8 +689,9 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
if (MayDeferGeneration(Global)) {
// If the value has already been used, add it directly to the
// DeferredDeclsToEmit list.
const char *MangledName = getMangledName(GD);
if (GlobalDeclMap.count(MangledName))
MangleBuffer MangledName;
getMangledName(MangledName, GD);
if (GetGlobalValue(MangledName))
DeferredDeclsToEmit.push_back(GD);
else {
// Otherwise, remember that we saw a deferred decl with this name. The
@@ -753,11 +747,12 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
///
/// If D is non-null, it specifies a decl that correspond to this. This is used
/// to set the attributes on the function when it is first created.
llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName,
const llvm::Type *Ty,
GlobalDecl D) {
llvm::Constant *
CodeGenModule::GetOrCreateLLVMFunction(llvm::StringRef MangledName,
const llvm::Type *Ty,
GlobalDecl D) {
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry) {
if (WeakRefReferences.count(Entry)) {
const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl());
@@ -786,17 +781,15 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName,
}
llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty),
llvm::Function::ExternalLinkage,
"", &getModule());
F->setName(MangledName);
MangledName, &getModule());
assert(F->getName() == MangledName && "name was uniqued!");
if (D.getDecl())
SetFunctionAttributes(D, F, IsIncompleteFunction);
Entry = F;
// This is the first use or definition of a mangled name. If there is a
// deferred decl with this name, remember that we need to emit it at the end
// of the file.
llvm::DenseMap<const char*, GlobalDecl>::iterator DDI =
DeferredDecls.find(MangledName);
llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName);
if (DDI != DeferredDecls.end()) {
// Move the potentially referenced deferred decl to the DeferredDeclsToEmit
// list, and remove it from DeferredDecls (since we don't need it anymore).
@@ -839,16 +832,16 @@ llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
// If there was no specific requested type, just convert it now.
if (!Ty)
Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType());
return GetOrCreateLLVMFunction(getMangledName(GD), Ty, GD);
MangleBuffer MangledName;
getMangledName(MangledName, GD);
return GetOrCreateLLVMFunction(MangledName, Ty, GD);
}
/// CreateRuntimeFunction - Create a new runtime function with the specified
/// type and name.
llvm::Constant *
CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy,
const char *Name) {
// Convert Name to be a uniqued string from the IdentifierInfo table.
Name = getContext().Idents.get(Name).getNameStart();
llvm::StringRef Name) {
return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl());
}
@@ -870,11 +863,12 @@ static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D) {
///
/// If D is non-null, it specifies a decl that correspond to this. This is used
/// to set the attributes on the global when it is first created.
llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
const llvm::PointerType*Ty,
const VarDecl *D) {
llvm::Constant *
CodeGenModule::GetOrCreateLLVMGlobal(llvm::StringRef MangledName,
const llvm::PointerType *Ty,
const VarDecl *D) {
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry) {
if (WeakRefReferences.count(Entry)) {
if (D && !D->hasAttr<WeakAttr>())
@@ -893,8 +887,7 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
// This is the first use or definition of a mangled name. If there is a
// deferred decl with this name, remember that we need to emit it at the end
// of the file.
llvm::DenseMap<const char*, GlobalDecl>::iterator DDI =
DeferredDecls.find(MangledName);
llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName);
if (DDI != DeferredDecls.end()) {
// Move the potentially referenced deferred decl to the DeferredDeclsToEmit
// list, and remove it from DeferredDecls (since we don't need it anymore).
@@ -905,9 +898,8 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(getModule(), Ty->getElementType(), false,
llvm::GlobalValue::ExternalLinkage,
0, "", 0,
0, MangledName, 0,
false, Ty->getAddressSpace());
GV->setName(MangledName);
// Handle things which are present even on external declarations.
if (D) {
@@ -926,7 +918,7 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
GV->setThreadLocal(D->isThreadSpecified());
}
return Entry = GV;
return GV;
}
@@ -943,16 +935,17 @@ llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
const llvm::PointerType *PTy =
llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D);
MangleBuffer MangledName;
getMangledName(MangledName, D);
return GetOrCreateLLVMGlobal(MangledName, PTy, D);
}
/// CreateRuntimeVariable - Create a new runtime global variable with the
/// specified type and name.
llvm::Constant *
CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty,
const char *Name) {
// Convert Name to be a uniqued string from the IdentifierInfo table.
Name = getContext().Idents.get(Name).getNameStart();
llvm::StringRef Name) {
return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0);
}
@@ -963,8 +956,9 @@ void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
// If we have not seen a reference to this variable yet, place it
// into the deferred declarations table to be emitted if needed
// later.
const char *MangledName = getMangledName(D);
if (GlobalDeclMap.count(MangledName) == 0) {
MangleBuffer MangledName;
getMangledName(MangledName, D);
if (!GetGlobalValue(MangledName)) {
DeferredDecls[MangledName] = D;
return;
}
@@ -1133,12 +1127,11 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
GV->getType()->getElementType() != InitType ||
GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) {
// Remove the old entry from GlobalDeclMap so that we'll create a new one.
GlobalDeclMap.erase(getMangledName(D));
// Move the old entry aside so that we'll create a new one.
Entry->setName(llvm::StringRef());
// Make a new global with the correct type, this is now guaranteed to work.
GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
GV->takeName(cast<llvm::GlobalValue>(Entry));
// Replace all uses of the old global with the new global
llvm::Constant *NewPtrForOldDecl =
@@ -1296,11 +1289,10 @@ void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
//
// This happens if there is a prototype for a function
// (e.g. "int f()") and then a definition of a different type
// (e.g. "int f(int x)"). Start by making a new function of the
// correct type, RAUW, then steal the name.
GlobalDeclMap.erase(getMangledName(D));
// (e.g. "int f(int x)"). Move the old function aside so that it
// doesn't interfere with GetAddrOfFunction.
OldFn->setName(llvm::StringRef());
llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
NewFn->takeName(OldFn);
// If this is an implementation of a function without a prototype, try to
// replace any existing uses of the function (which may be calls) with uses
@@ -1336,23 +1328,29 @@ void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
AddGlobalDtor(Fn, DA->getPriority());
}
void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) {
void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
const AliasAttr *AA = D->getAttr<AliasAttr>();
assert(AA && "Not an alias?");
const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
MangleBuffer MangledName;
getMangledName(MangledName, GD);
// Unique the name through the identifier table.
const char *AliaseeName =
getContext().Idents.get(AA->getAliasee()).getNameStart();
// 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.
llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
if (Entry && !Entry->isDeclaration())
return;
const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
// 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, GlobalDecl());
Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl());
else
Aliasee = GetOrCreateLLVMGlobal(AliaseeName,
Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy), 0);
// Create the new alias itself, but don't set a name yet.
@@ -1361,18 +1359,9 @@ void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) {
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) {
assert(Entry->isDeclaration());
// If there is a declaration in the module, then we had an extern followed
// by the alias, as in:
// extern int test6();
@@ -1380,16 +1369,15 @@ void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) {
// int test6() __attribute__((alias("test7")));
//
// Remove it and replace uses of it with the alias.
GA->takeName(Entry);
Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
Entry->getType()));
Entry->eraseFromParent();
} else {
GA->setName(MangledName.getString());
}
// Now we know that there is no conflict, set the name.
Entry = GA;
GA->setName(MangledName);
// Set attributes which are particular to an alias; this is a
// specialization of the attributes which may be set on a global
// variable/function.
@@ -1426,8 +1414,6 @@ llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
const llvm::FunctionType *Ty =
cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType()));
// Unique the name through the identifier table.
Name = getContext().Idents.get(Name).getNameStart();
return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD));
}