r202305 - Refactor linkage computation in CGObjCMac.cpp.
Rafael Espindola
rafael.espindola at gmail.com
Wed Feb 26 14:25:45 PST 2014
Author: rafael
Date: Wed Feb 26 16:25:45 2014
New Revision: 202305
URL: http://llvm.org/viewvc/llvm-project?rev=202305&view=rev
Log:
Refactor linkage computation in CGObjCMac.cpp.
Before this patch the globals were created with the wrong linkage and patched
afterwards. From the comments it looks like something would complain about
having an internal GV with no initializer. At least in clang the verifier will
only run way after we set the initializer, so that is not a problem.
This patch should be a nop. It just figures out the linkage earlier and
converts the old calls to setLinkage to asserts. The only case where that is
not possible is when we first see a weak import that is then implemented. In
that case we have to change the linkage, but that is the only setLinkage left.
Modified:
cfe/trunk/lib/CodeGen/CGObjCGNU.cpp
cfe/trunk/lib/CodeGen/CGObjCMac.cpp
cfe/trunk/lib/CodeGen/CGObjCRuntime.h
Modified: cfe/trunk/lib/CodeGen/CGObjCGNU.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCGNU.cpp?rev=202305&r1=202304&r2=202305&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCGNU.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCGNU.cpp Wed Feb 26 16:25:45 2014
@@ -573,8 +573,9 @@ public:
QualType T) {
return NULLPtr;
}
-
- virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) {
+
+ llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
+ bool Weak = false) LLVM_OVERRIDE {
return 0;
}
};
Modified: cfe/trunk/lib/CodeGen/CGObjCMac.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCMac.cpp?rev=202305&r1=202304&r2=202305&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCMac.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCMac.cpp Wed Feb 26 16:25:45 2014
@@ -1272,7 +1272,8 @@ public:
/// GetClassGlobal - Return the global variable for the Objective-C
/// class of the given name.
- virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) {
+ llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
+ bool Weak = false) LLVM_OVERRIDE {
llvm_unreachable("CGObjCMac::GetClassGlobal");
}
};
@@ -1321,7 +1322,8 @@ private:
llvm::Constant *IsAGV,
llvm::Constant *SuperClassGV,
llvm::Constant *ClassRoGV,
- bool HiddenVisibility);
+ bool HiddenVisibility,
+ bool Weak = false);
llvm::Constant *GetMethodConstant(const ObjCMethodDecl *MD);
@@ -1372,15 +1374,16 @@ private:
/// GetClassGlobal - Return the global variable for the Objective-C
/// class of the given name.
- llvm::GlobalVariable *GetClassGlobal(const std::string &Name);
-
+ llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
+ bool Weak = false) LLVM_OVERRIDE;
+
/// EmitClassRef - Return a Value*, of type ObjCTypes.ClassPtrTy,
/// for the given class reference.
llvm::Value *EmitClassRef(CodeGenFunction &CGF,
const ObjCInterfaceDecl *ID);
llvm::Value *EmitClassRefFromId(CodeGenFunction &CGF,
- IdentifierInfo *II);
+ IdentifierInfo *II, bool Weak);
llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF);
@@ -2649,7 +2652,7 @@ llvm::Constant *CGObjCMac::GetOrEmitProt
if (Entry) {
// Already created, fix the linkage and update the initializer.
- Entry->setLinkage(llvm::GlobalValue::InternalLinkage);
+ assert(Entry->getLinkage() == llvm::GlobalValue::InternalLinkage);
Entry->setInitializer(Init);
} else {
Entry =
@@ -2677,7 +2680,7 @@ llvm::Constant *CGObjCMac::GetOrEmitProt
// contents for protocols which were referenced but never defined.
Entry =
new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ProtocolTy, false,
- llvm::GlobalValue::ExternalLinkage,
+ llvm::GlobalValue::InternalLinkage,
0,
"\01L_OBJC_PROTOCOL_" + PD->getName());
Entry->setSection("__OBJC,__protocol,regular,no_dead_strip");
@@ -3135,11 +3138,11 @@ void CGObjCMac::GenerateClass(const ObjC
Name += ClassName;
const char *Section = "__OBJC,__class,regular,no_dead_strip";
// Check for a forward reference.
- llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name);
+ llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name, true);
if (GV) {
assert(GV->getType()->getElementType() == ObjCTypes.ClassTy &&
"Forward metaclass reference has incorrect type.");
- GV->setLinkage(llvm::GlobalValue::InternalLinkage);
+ assert(GV->getLinkage() == llvm::GlobalValue::InternalLinkage);
GV->setInitializer(Init);
GV->setSection(Section);
GV->setAlignment(4);
@@ -3203,11 +3206,11 @@ llvm::Constant *CGObjCMac::EmitMetaClass
Name += ID->getName();
// Check for a forward reference.
- llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name);
+ llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name, true);
if (GV) {
assert(GV->getType()->getElementType() == ObjCTypes.ClassTy &&
"Forward metaclass reference has incorrect type.");
- GV->setLinkage(llvm::GlobalValue::InternalLinkage);
+ assert(GV->getLinkage() == llvm::GlobalValue::InternalLinkage);
GV->setInitializer(Init);
} else {
GV = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassTy, false,
@@ -3241,7 +3244,7 @@ llvm::Constant *CGObjCMac::EmitMetaClass
// Generate as an external reference to keep a consistent
// module. This will be patched up when we emit the metaclass.
return new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassTy, false,
- llvm::GlobalValue::ExternalLinkage,
+ llvm::GlobalValue::InternalLinkage,
0,
Name);
}
@@ -3257,7 +3260,7 @@ llvm::Value *CGObjCMac::EmitSuperClassRe
return GV;
} else {
return new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassTy, false,
- llvm::GlobalValue::ExternalLinkage,
+ llvm::GlobalValue::InternalLinkage,
0,
Name);
}
@@ -4995,7 +4998,7 @@ void CGObjCMac::FinishModule() {
Values[2] = llvm::Constant::getNullValue(ObjCTypes.ProtocolListPtrTy);
Values[3] = Values[4] =
llvm::Constant::getNullValue(ObjCTypes.MethodDescriptionListPtrTy);
- I->second->setLinkage(llvm::GlobalValue::InternalLinkage);
+ assert(I->second->getLinkage() == llvm::GlobalValue::InternalLinkage);
I->second->setInitializer(llvm::ConstantStruct::get(ObjCTypes.ProtocolTy,
Values));
CGM.AddUsedGlobal(I->second);
@@ -5536,21 +5539,7 @@ void CGObjCNonFragileABIMac::FinishNonFr
AddModuleClassList(DefinedClasses,
"\01L_OBJC_LABEL_CLASS_$",
"__DATA, __objc_classlist, regular, no_dead_strip");
-
- for (unsigned i = 0, e = DefinedClasses.size(); i < e; i++) {
- llvm::GlobalValue *IMPLGV = DefinedClasses[i];
- if (IMPLGV->getLinkage() != llvm::GlobalValue::ExternalWeakLinkage)
- continue;
- IMPLGV->setLinkage(llvm::GlobalValue::ExternalLinkage);
- }
-
- for (unsigned i = 0, e = DefinedMetaClasses.size(); i < e; i++) {
- llvm::GlobalValue *IMPLGV = DefinedMetaClasses[i];
- if (IMPLGV->getLinkage() != llvm::GlobalValue::ExternalWeakLinkage)
- continue;
- IMPLGV->setLinkage(llvm::GlobalValue::ExternalLinkage);
- }
-
+
AddModuleClassList(DefinedNonLazyClasses,
"\01L_OBJC_LABEL_NONLAZY_CLASS_$",
"__DATA, __objc_nlclslist, regular, no_dead_strip");
@@ -5742,12 +5731,9 @@ llvm::GlobalVariable * CGObjCNonFragileA
/// struct class_ro_t *ro;
/// }
///
-llvm::GlobalVariable * CGObjCNonFragileABIMac::BuildClassMetaData(
- std::string &ClassName,
- llvm::Constant *IsAGV,
- llvm::Constant *SuperClassGV,
- llvm::Constant *ClassRoGV,
- bool HiddenVisibility) {
+llvm::GlobalVariable *CGObjCNonFragileABIMac::BuildClassMetaData(
+ std::string &ClassName, llvm::Constant *IsAGV, llvm::Constant *SuperClassGV,
+ llvm::Constant *ClassRoGV, bool HiddenVisibility, bool Weak) {
llvm::Constant *Values[] = {
IsAGV,
SuperClassGV,
@@ -5762,7 +5748,7 @@ llvm::GlobalVariable * CGObjCNonFragileA
llvm::PointerType::getUnqual(ObjCTypes.ImpnfABITy));
llvm::Constant *Init = llvm::ConstantStruct::get(ObjCTypes.ClassnfABITy,
Values);
- llvm::GlobalVariable *GV = GetClassGlobal(ClassName);
+ llvm::GlobalVariable *GV = GetClassGlobal(ClassName, Weak);
GV->setInitializer(Init);
GV->setSection("__DATA, __objc_data");
GV->setAlignment(
@@ -5849,30 +5835,35 @@ void CGObjCNonFragileABIMac::GenerateCla
// class is root
flags |= NonFragileABI_Class_Root;
SuperClassGV = GetClassGlobal(ObjCClassName + ClassName);
- IsAGV = GetClassGlobal(ObjCMetaClassName + ClassName);
+ IsAGV = GetClassGlobal(ObjCMetaClassName + ClassName,
+ ID->getClassInterface()->isWeakImported());
+
+ // We are implementing a weak imported interface. Give it external
+ // linkage.
+ if (!ID->isWeakImported() && ID->getClassInterface()->isWeakImported())
+ IsAGV->setLinkage(llvm::GlobalVariable::ExternalLinkage);
} else {
// Has a root. Current class is not a root.
const ObjCInterfaceDecl *Root = ID->getClassInterface();
while (const ObjCInterfaceDecl *Super = Root->getSuperClass())
Root = Super;
- IsAGV = GetClassGlobal(ObjCMetaClassName + Root->getNameAsString());
- if (Root->isWeakImported())
- IsAGV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
+ IsAGV = GetClassGlobal(ObjCMetaClassName + Root->getNameAsString(),
+ Root->isWeakImported());
// work on super class metadata symbol.
std::string SuperClassName =
ObjCMetaClassName +
ID->getClassInterface()->getSuperClass()->getNameAsString();
- SuperClassGV = GetClassGlobal(SuperClassName);
- if (ID->getClassInterface()->getSuperClass()->isWeakImported())
- SuperClassGV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
+ SuperClassGV = GetClassGlobal(
+ SuperClassName,
+ ID->getClassInterface()->getSuperClass()->isWeakImported());
}
llvm::GlobalVariable *CLASS_RO_GV = BuildClassRoTInitializer(flags,
InstanceStart,
InstanceSize,ID);
std::string TClassName = ObjCMetaClassName + ClassName;
- llvm::GlobalVariable *MetaTClass =
- BuildClassMetaData(TClassName, IsAGV, SuperClassGV, CLASS_RO_GV,
- classIsHidden);
+ llvm::GlobalVariable *MetaTClass = BuildClassMetaData(
+ TClassName, IsAGV, SuperClassGV, CLASS_RO_GV, classIsHidden,
+ ID->isWeakImported());
DefinedMetaClasses.push_back(MetaTClass);
// Metadata for the class
@@ -5903,9 +5894,9 @@ void CGObjCNonFragileABIMac::GenerateCla
// Has a root. Current class is not a root.
std::string RootClassName =
ID->getClassInterface()->getSuperClass()->getNameAsString();
- SuperClassGV = GetClassGlobal(ObjCClassName + RootClassName);
- if (ID->getClassInterface()->getSuperClass()->isWeakImported())
- SuperClassGV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
+ SuperClassGV = GetClassGlobal(
+ ObjCClassName + RootClassName,
+ ID->getClassInterface()->getSuperClass()->isWeakImported());
}
GetClassSizeInfo(ID, InstanceStart, InstanceSize);
CLASS_RO_GV = BuildClassRoTInitializer(flags,
@@ -5987,10 +5978,9 @@ void CGObjCNonFragileABIMac::GenerateCat
llvm::Constant *Values[6];
Values[0] = GetClassName(OCD->getIdentifier());
// meta-class entry symbol
- llvm::GlobalVariable *ClassGV = GetClassGlobal(ExtClassName);
- if (Interface->isWeakImported())
- ClassGV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
-
+ llvm::GlobalVariable *ClassGV =
+ GetClassGlobal(ExtClassName, Interface->isWeakImported());
+
Values[1] = ClassGV;
std::vector<llvm::Constant*> Methods;
std::string MethodListName(Prefix);
@@ -6359,7 +6349,7 @@ llvm::Constant *CGObjCNonFragileABIMac::
if (Entry) {
// Already created, fix the linkage and update the initializer.
- Entry->setLinkage(llvm::GlobalValue::WeakAnyLinkage);
+ assert(Entry->getLinkage() == llvm::GlobalValue::WeakAnyLinkage);
Entry->setInitializer(Init);
} else {
Entry =
@@ -6651,25 +6641,29 @@ CGObjCNonFragileABIMac::GenerateMessageS
}
llvm::GlobalVariable *
-CGObjCNonFragileABIMac::GetClassGlobal(const std::string &Name) {
+CGObjCNonFragileABIMac::GetClassGlobal(const std::string &Name, bool Weak) {
+ llvm::GlobalValue::LinkageTypes L =
+ Weak ? llvm::GlobalValue::ExternalWeakLinkage
+ : llvm::GlobalValue::ExternalLinkage;
+
llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name);
- if (!GV) {
+ if (!GV)
GV = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassnfABITy,
- false, llvm::GlobalValue::ExternalLinkage,
- 0, Name);
- }
+ false, L, 0, Name);
+ assert(GV->getLinkage() == L);
return GV;
}
llvm::Value *CGObjCNonFragileABIMac::EmitClassRefFromId(CodeGenFunction &CGF,
- IdentifierInfo *II) {
+ IdentifierInfo *II,
+ bool Weak) {
llvm::GlobalVariable *&Entry = ClassReferences[II];
if (!Entry) {
std::string ClassName(getClassSymbolPrefix() + II->getName().str());
- llvm::GlobalVariable *ClassGV = GetClassGlobal(ClassName);
+ llvm::GlobalVariable *ClassGV = GetClassGlobal(ClassName, Weak);
Entry =
new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassnfABIPtrTy,
false, llvm::GlobalValue::InternalLinkage,
@@ -6687,13 +6681,13 @@ llvm::Value *CGObjCNonFragileABIMac::Emi
llvm::Value *CGObjCNonFragileABIMac::EmitClassRef(CodeGenFunction &CGF,
const ObjCInterfaceDecl *ID) {
- return EmitClassRefFromId(CGF, ID->getIdentifier());
+ return EmitClassRefFromId(CGF, ID->getIdentifier(), ID->isWeakImported());
}
llvm::Value *CGObjCNonFragileABIMac::EmitNSAutoreleasePoolClassRef(
CodeGenFunction &CGF) {
IdentifierInfo *II = &CGM.getContext().Idents.get("NSAutoreleasePool");
- return EmitClassRefFromId(CGF, II);
+ return EmitClassRefFromId(CGF, II, false);
}
llvm::Value *
@@ -6751,8 +6745,8 @@ llvm::Value *CGObjCNonFragileABIMac::Get
const ObjCInterfaceDecl *ID) {
if (ID->isWeakImported()) {
std::string ClassName(getClassSymbolPrefix() + ID->getNameAsString());
- llvm::GlobalVariable *ClassGV = GetClassGlobal(ClassName);
- ClassGV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
+ llvm::GlobalVariable *ClassGV = GetClassGlobal(ClassName, true);
+ assert(ClassGV->getLinkage() == llvm::GlobalValue::ExternalWeakLinkage);
}
return EmitClassRef(CGF, ID);
@@ -7053,27 +7047,29 @@ CGObjCNonFragileABIMac::GetInterfaceEHTy
llvm::Constant *Init =
llvm::ConstantStruct::get(ObjCTypes.EHTypeTy, Values);
+ llvm::GlobalValue::LinkageTypes L = ForDefinition
+ ? llvm::GlobalValue::ExternalLinkage
+ : llvm::GlobalValue::WeakAnyLinkage;
if (Entry) {
Entry->setInitializer(Init);
} else {
Entry = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.EHTypeTy, false,
- llvm::GlobalValue::WeakAnyLinkage,
+ L,
Init,
("OBJC_EHTYPE_$_" +
ID->getIdentifier()->getName()));
}
+ assert(Entry->getLinkage() == L);
if (ID->getVisibility() == HiddenVisibility)
Entry->setVisibility(llvm::GlobalValue::HiddenVisibility);
Entry->setAlignment(CGM.getDataLayout().getABITypeAlignment(
ObjCTypes.EHTypeTy));
- if (ForDefinition) {
+ if (ForDefinition)
Entry->setSection("__DATA,__objc_const");
- Entry->setLinkage(llvm::GlobalValue::ExternalLinkage);
- } else {
+ else
Entry->setSection("__DATA,__datacoal_nt,coalesced");
- }
return Entry;
}
Modified: cfe/trunk/lib/CodeGen/CGObjCRuntime.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCRuntime.h?rev=202305&r1=202304&r2=202305&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCRuntime.h (original)
+++ cfe/trunk/lib/CodeGen/CGObjCRuntime.h Wed Feb 26 16:25:45 2014
@@ -268,7 +268,8 @@ public:
const CodeGen::CGBlockInfo &blockInfo) = 0;
virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM,
QualType T) = 0;
- virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) = 0;
+ virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
+ bool Weak = false) = 0;
struct MessageSendInfo {
const CGFunctionInfo &CallInfo;
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