Rework codegen emission of globals
- No (intended) functionality change.
- Primary purpose is to clearly separate (lazy) construction of
globals that are a forward declaration or tentative definition from
those that are the final definition.
- Lazy construction is now encapsulated in
GetAddrOf{Function,GlobalVar} while final definitions are
constructed in EmitGlobal{Function,Var}Definition.
- External interface for dealing with globals is now limited to
EmitGlobal and GetAddrOf{Function,GlobalVar}.
- Also updated helper functions dealing with statics, annotations,
and ctors to be private.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54179 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 565286c..1e91ac2 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -153,8 +153,6 @@
CtorValues));
}
-
-
void CodeGenModule::EmitAnnotations() {
if (Annotations.empty())
return;
@@ -171,16 +169,6 @@
gv->setSection("llvm.metadata");
}
-/// ReplaceMapValuesWith - This is a really slow and bad function that
-/// searches for any entries in GlobalDeclMap that point to OldVal, changing
-/// them to point to NewVal. This is badbadbad, FIXME!
-void CodeGenModule::ReplaceMapValuesWith(llvm::Constant *OldVal,
- llvm::Constant *NewVal) {
- for (llvm::DenseMap<const Decl*, llvm::Constant*>::iterator
- I = GlobalDeclMap.begin(), E = GlobalDeclMap.end(); I != E; ++I)
- if (I->second == OldVal) I->second = NewVal;
-}
-
bool hasAggregateLLVMType(QualType T) {
return !T->isRealType() && !T->isPointerLikeType() &&
!T->isVoidType() && !T->isVectorType() && !T->isFunctionType();
@@ -251,110 +239,6 @@
SetGlobalValueAttributes(FD, F);
}
-
-
-llvm::Constant *CodeGenModule::GetAddrOfFunctionDecl(const FunctionDecl *D,
- bool isDefinition) {
- // See if it is already in the map. If so, just return it.
- llvm::Constant *&Entry = GlobalDeclMap[D];
- if (!isDefinition && Entry) return Entry;
-
- const llvm::Type *Ty = getTypes().ConvertType(D->getType());
-
- // Check to see if the function already exists.
- llvm::Function *F = getModule().getFunction(D->getName());
- const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
-
- // If it doesn't already exist, just create and return an entry.
- if (F == 0) {
- // FIXME: param attributes for sext/zext etc.
- if (D->getBody() || !D->getAttr<AliasAttr>())
- F = llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
- D->getName(), &getModule());
- else {
- const std::string& aliaseeName = D->getAttr<AliasAttr>()->getAliasee();
- llvm::Function *aliasee = getModule().getFunction(aliaseeName);
- llvm::GlobalValue *alias = new llvm::GlobalAlias(aliasee->getType(),
- llvm::Function::ExternalLinkage,
- D->getName(),
- aliasee,
- &getModule());
- SetGlobalValueAttributes(D, alias);
- return Entry = alias;
- }
-
- SetFunctionAttributes(D, F, FTy);
- return Entry = F;
- }
-
- // If the pointer type matches, just return it.
- llvm::Type *PFTy = llvm::PointerType::getUnqual(Ty);
- if (PFTy == F->getType()) return Entry = F;
-
- // If this isn't a definition, just return it casted to the right type.
- if (!isDefinition)
- return Entry = llvm::ConstantExpr::getBitCast(F, PFTy);
-
- // Otherwise, we have a definition after a prototype with the wrong type.
- // F is the Function* for the one with the wrong type, we must make a new
- // Function* and update everything that used F (a declaration) with the new
- // Function* (which will be a definition).
- //
- // 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.
- llvm::Function *NewFn = llvm::Function::Create(FTy,
- llvm::Function::ExternalLinkage,
- "", &getModule());
- NewFn->takeName(F);
-
- // Replace uses of F with the Function we will endow with a body.
- llvm::Constant *NewPtrForOldDecl =
- llvm::ConstantExpr::getBitCast(NewFn, F->getType());
- F->replaceAllUsesWith(NewPtrForOldDecl);
-
- // FIXME: Update the globaldeclmap for the previous decl of this name. We
- // really want a way to walk all of these, but we don't have it yet. This
- // is incredibly slow!
- ReplaceMapValuesWith(F, NewPtrForOldDecl);
-
- // Ok, delete the old function now, which is dead.
- assert(F->isDeclaration() && "Shouldn't replace non-declaration");
- F->eraseFromParent();
-
- SetFunctionAttributes(D, NewFn, FTy);
- // Return the new function which has the right type.
- return Entry = NewFn;
-}
-
-llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
- bool isDefinition) {
- assert(D->hasGlobalStorage() && "Not a global variable");
- assert(!isDefinition && "This shouldn't be called for definitions!");
-
- // See if it is already in the map.
- llvm::Constant *&Entry = GlobalDeclMap[D];
- if (Entry) return Entry;
-
- QualType ASTTy = D->getType();
- const llvm::Type *Ty = getTypes().ConvertTypeForMem(ASTTy);
-
- // Check to see if the global already exists.
- llvm::GlobalVariable *GV = getModule().getGlobalVariable(D->getName(), true);
-
- // If it doesn't already exist, just create and return an entry.
- if (GV == 0) {
- return Entry = new llvm::GlobalVariable(Ty, false,
- llvm::GlobalValue::ExternalLinkage,
- 0, D->getName(), &getModule(), 0,
- ASTTy.getAddressSpace());
- }
-
- // Otherwise, it already exists; return the existing version
- llvm::PointerType *PTy = llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
- return Entry = llvm::ConstantExpr::getBitCast(GV, PTy);
-}
-
void CodeGenModule::EmitObjCMethod(const ObjCMethodDecl *OMD) {
// If this is not a prototype, emit the body.
if (OMD->getBody())
@@ -509,25 +393,6 @@
ClassMethodSels, ClassMethodTypes, Protocols);
}
-
-void CodeGenModule::EmitFunction(const FunctionDecl *FD) {
- // If this is not a prototype, emit the body.
- if (!FD->isThisDeclarationADefinition()) {
- if (FD->getAttr<AliasAttr>())
- GetAddrOfFunctionDecl(FD, true);
- return;
- }
-
- // If the function is a static, defer code generation until later so we can
- // easily omit unused statics.
- if (FD->getStorageClass() != FunctionDecl::Static) {
- CodeGenFunction(*this).GenerateCode(FD);
- return;
- }
-
- StaticDecls.push_back(FD);
-}
-
void CodeGenModule::EmitStatics() {
// Emit code for each used static decl encountered. Since a previously unused
// static decl may become used during the generation of code for a static
@@ -536,7 +401,7 @@
do {
Changed = false;
for (unsigned i = 0, e = StaticDecls.size(); i != e; ++i) {
- const Decl *D = StaticDecls[i];
+ const ValueDecl *D = StaticDecls[i];
// Check if we have used a decl with the same name
// FIXME: The AST should have some sort of aggregate decls or
@@ -549,17 +414,9 @@
continue;
}
- // If this is a function decl, generate code for the static function if it
- // has a body. Otherwise, we must have a var decl for a static global
- // variable.
- if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
- if (FD->getBody())
- CodeGenFunction(*this).GenerateCode(FD);
- else if (FD->getAttr<AliasAttr>())
- GetAddrOfFunctionDecl(FD, true);
- } else {
- EmitGlobalVarInit(cast<VarDecl>(D));
- }
+ // Emit the definition.
+ EmitGlobalDefinition(D);
+
// Erase the used decl from the list.
StaticDecls[i] = StaticDecls.back();
StaticDecls.pop_back();
@@ -572,10 +429,6 @@
} while (Changed);
}
-llvm::Constant *CodeGenModule::EmitGlobalInit(const Expr *Expr) {
- return EmitConstantExpr(Expr);
-}
-
/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the
/// annotation information for a given GlobalValue. The annotation struct is
/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the
@@ -620,25 +473,85 @@
return llvm::ConstantStruct::get(Fields, 4, false);
}
-void CodeGenModule::EmitGlobalVar(const VarDecl *D) {
- // If the VarDecl is a static, defer code generation until later so we can
- // easily omit unused statics.
- if (D->getStorageClass() == VarDecl::Static) {
- StaticDecls.push_back(D);
+/// ReplaceMapValuesWith - This is a really slow and bad function that
+/// searches for any entries in GlobalDeclMap that point to OldVal, changing
+/// them to point to NewVal. This is badbadbad, FIXME!
+void CodeGenModule::ReplaceMapValuesWith(llvm::Constant *OldVal,
+ llvm::Constant *NewVal) {
+ for (llvm::DenseMap<const Decl*, llvm::Constant*>::iterator
+ I = GlobalDeclMap.begin(), E = GlobalDeclMap.end(); I != E; ++I)
+ if (I->second == OldVal) I->second = NewVal;
+}
+
+void CodeGenModule::EmitGlobal(const ValueDecl *Global) {
+ bool isDef, isStatic;
+
+ if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
+ isDef = (FD->isThisDeclarationADefinition() ||
+ FD->getAttr<AliasAttr>());
+ isStatic = FD->getStorageClass() == FunctionDecl::Static;
+ } else if (const VarDecl *VD = cast<VarDecl>(Global)) {
+ assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
+
+ isDef = !(VD->getStorageClass() == VarDecl::Extern && VD->getInit() == 0);
+ isStatic = VD->getStorageClass() == VarDecl::Static;
+ } else {
+ assert(0 && "Invalid argument to EmitGlobal");
return;
}
- // If this is just a forward declaration of the variable, don't emit it now,
- // allow it to be emitted lazily on its first use.
- if (D->getStorageClass() == VarDecl::Extern && D->getInit() == 0)
+ // Forward declarations are emitted lazily on first use.
+ if (!isDef)
return;
-
- EmitGlobalVarInit(D);
+
+ // If the global is a static, defer code generation until later so
+ // we can easily omit unused statics.
+ if (isStatic) {
+ StaticDecls.push_back(Global);
+ return;
+ }
+
+ // Otherwise emit the definition.
+ EmitGlobalDefinition(Global);
}
-void CodeGenModule::EmitGlobalVarInit(const VarDecl *D) {
+void CodeGenModule::EmitGlobalDefinition(const ValueDecl *D) {
+ if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+ EmitGlobalFunctionDefinition(FD);
+ } else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
+ EmitGlobalVarDefinition(VD);
+ } else {
+ assert(0 && "Invalid argument to EmitGlobalDefinition()");
+ }
+}
+
+llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D) {
assert(D->hasGlobalStorage() && "Not a global variable");
+ // See if it is already in the map.
+ llvm::Constant *&Entry = GlobalDeclMap[D];
+ if (Entry) return Entry;
+
+ QualType ASTTy = D->getType();
+ const llvm::Type *Ty = getTypes().ConvertTypeForMem(ASTTy);
+
+ // Check to see if the global already exists.
+ llvm::GlobalVariable *GV = getModule().getGlobalVariable(D->getName(), true);
+
+ // If it doesn't already exist, just create and return an entry.
+ if (GV == 0) {
+ return Entry = new llvm::GlobalVariable(Ty, false,
+ llvm::GlobalValue::ExternalLinkage,
+ 0, D->getName(), &getModule(), 0,
+ ASTTy.getAddressSpace());
+ }
+
+ // Otherwise, it already exists; return the existing version
+ llvm::PointerType *PTy = llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
+ return Entry = llvm::ConstantExpr::getBitCast(GV, PTy);
+}
+
+void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
llvm::Constant *Init = 0;
QualType ASTTy = D->getType();
const llvm::Type *VarTy = getTypes().ConvertTypeForMem(ASTTy);
@@ -659,7 +572,7 @@
}
Init = llvm::Constant::getNullValue(InitTy);
} else {
- Init = EmitGlobalInit(D->getInit());
+ Init = EmitConstantExpr(D->getInit());
}
const llvm::Type* InitType = Init->getType();
@@ -772,6 +685,111 @@
}
}
+llvm::GlobalValue *
+CodeGenModule::EmitForwardFunctionDefinition(const FunctionDecl *D) {
+ // FIXME: param attributes for sext/zext etc.
+ if (const AliasAttr *AA = D->getAttr<AliasAttr>()) {
+ assert(!D->getBody() && "Unexpected alias attr on function with body.");
+
+ const std::string& aliaseeName = AA->getAliasee();
+ llvm::Function *aliasee = getModule().getFunction(aliaseeName);
+ llvm::GlobalValue *alias = new llvm::GlobalAlias(aliasee->getType(),
+ llvm::Function::ExternalLinkage,
+ D->getName(),
+ aliasee,
+ &getModule());
+ SetGlobalValueAttributes(D, alias);
+ return alias;
+ } else {
+ const llvm::Type *Ty = getTypes().ConvertType(D->getType());
+ const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
+ llvm::Function *F = llvm::Function::Create(FTy,
+ llvm::Function::ExternalLinkage,
+ D->getName(), &getModule());
+
+ SetFunctionAttributes(D, F, FTy);
+ return F;
+ }
+}
+
+llvm::Constant *CodeGenModule::GetAddrOfFunction(const FunctionDecl *D) {
+ // See if it is already in the map. If so, just return it.
+ llvm::Constant *&Entry = GlobalDeclMap[D];
+ if (Entry) return Entry;
+
+ // Check to see if the function already exists; this occurs when
+ // this decl shadows a previous one. If it exists we bitcast it to
+ // the proper type for this decl and return.
+ llvm::Function *F = getModule().getFunction(D->getName());
+ if (F) {
+ const llvm::Type *Ty = getTypes().ConvertType(D->getType());
+ llvm::Type *PFTy = llvm::PointerType::getUnqual(Ty);
+ return Entry = llvm::ConstantExpr::getBitCast(F, PFTy);
+ }
+
+ // It doesn't exist; create and return an entry.
+ return Entry = EmitForwardFunctionDefinition(D);
+}
+
+void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) {
+ llvm::Constant *&Entry = GlobalDeclMap[D];
+
+ const llvm::Type *Ty = getTypes().ConvertType(D->getType());
+ const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
+
+ // Check to see if the function already exists.
+ llvm::Function *F = getModule().getFunction(D->getName());
+
+ // If it doesn't already exist, just create and return an entry.
+ if (F == 0) {
+ Entry = EmitForwardFunctionDefinition(D);
+ } else {
+ // If the pointer type matches, just return it.
+ llvm::Type *PFTy = llvm::PointerType::getUnqual(Ty);
+ if (PFTy == F->getType()) {
+ Entry = F;
+ } else {
+ // Otherwise, we have a definition after a prototype with the wrong type.
+ // F is the Function* for the one with the wrong type, we must make a new
+ // Function* and update everything that used F (a declaration) with the new
+ // Function* (which will be a definition).
+ //
+ // 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.
+ llvm::Function *NewFn = llvm::Function::Create(FTy,
+ llvm::Function::ExternalLinkage,
+ "", &getModule());
+ NewFn->takeName(F);
+
+ // Replace uses of F with the Function we will endow with a body.
+ llvm::Constant *NewPtrForOldDecl =
+ llvm::ConstantExpr::getBitCast(NewFn, F->getType());
+ F->replaceAllUsesWith(NewPtrForOldDecl);
+
+ // FIXME: Update the globaldeclmap for the previous decl of this name. We
+ // really want a way to walk all of these, but we don't have it yet. This
+ // is incredibly slow!
+ ReplaceMapValuesWith(F, NewPtrForOldDecl);
+
+ // Ok, delete the old function now, which is dead.
+ assert(F->isDeclaration() && "Shouldn't replace non-declaration");
+ F->eraseFromParent();
+
+ SetFunctionAttributes(D, NewFn, FTy);
+ // Return the new function which has the right type.
+ Entry = NewFn;
+ }
+ }
+
+ if (D->getAttr<AliasAttr>()) {
+ ;
+ } else {
+ llvm::Function *Fn = cast<llvm::Function>(Entry);
+ CodeGenFunction(*this).GenerateCode(D, Fn);
+ }
+}
+
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);