[CodeGen][ObjC] Remove the leading `l_` from ObjC symbols and make
private symbols in the __DATA segment internal.
This prevents the linker from removing the symbol names. Keeping the
symbols visible enables tools to collect various information about the
symbols, for example, tools that discover whether or not a symbol gets
dirtied.
rdar://problem/48887111
Differential Revision: https://reviews.llvm.org/D61454
llvm-svn: 360359
diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index ad141d6..79b00f2 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -1809,6 +1809,28 @@
return false;
}
+static llvm::GlobalValue::LinkageTypes
+getLinkageTypeForObjCMetadata(CodeGenModule &CGM, StringRef Section) {
+ if (CGM.getTriple().isOSBinFormatMachO() &&
+ (Section.empty() || Section.startswith("__DATA")))
+ return llvm::GlobalValue::InternalLinkage;
+ return llvm::GlobalValue::PrivateLinkage;
+}
+
+/// A helper function to create an internal or private global variable.
+static llvm::GlobalVariable *
+finishAndCreateGlobal(ConstantInitBuilder::StructBuilder &Builder,
+ const llvm::Twine &Name, CodeGenModule &CGM) {
+ std::string SectionName;
+ if (CGM.getTriple().isOSBinFormatMachO())
+ SectionName = "__DATA, __objc_const";
+ auto *GV = Builder.finishAndCreateGlobal(
+ Name, CGM.getPointerAlign(), /*constant*/ false,
+ getLinkageTypeForObjCMetadata(CGM, SectionName));
+ GV->setSection(SectionName);
+ return GV;
+}
+
/* *** CGObjCMac Public Interface *** */
CGObjCMac::CGObjCMac(CodeGen::CodeGenModule &cgm) : CGObjCCommonMac(cgm),
@@ -3105,7 +3127,7 @@
values.add(classProperties);
// No special section, but goes in llvm.used
- return CreateMetadataVar("\01l_OBJC_PROTOCOLEXT_" + PD->getName(), values,
+ return CreateMetadataVar("_OBJC_PROTOCOLEXT_" + PD->getName(), values,
StringRef(), CGM.getPointerAlign(), true);
}
@@ -3338,9 +3360,9 @@
// If there is no category @interface then there can be no properties.
if (Category) {
- Values.add(EmitPropertyList("\01l_OBJC_$_PROP_LIST_" + ExtName.str(),
+ Values.add(EmitPropertyList("_OBJC_$_PROP_LIST_" + ExtName.str(),
OCD, Category, ObjCTypes, false));
- Values.add(EmitPropertyList("\01l_OBJC_$_CLASS_PROP_LIST_" + ExtName.str(),
+ Values.add(EmitPropertyList("_OBJC_$_CLASS_PROP_LIST_" + ExtName.str(),
OCD, Category, ObjCTypes, true));
} else {
Values.addNullPointer(ObjCTypes.PropertyListPtrTy);
@@ -3686,8 +3708,8 @@
// Properties.
llvm::Constant *propertyList =
- EmitPropertyList((isMetaclass ? Twine("\01l_OBJC_$_CLASS_PROP_LIST_")
- : Twine("\01l_OBJC_$_PROP_LIST_"))
+ EmitPropertyList((isMetaclass ? Twine("_OBJC_$_CLASS_PROP_LIST_")
+ : Twine("_OBJC_$_PROP_LIST_"))
+ ID->getName(),
ID, ID->getClassInterface(), ObjCTypes, isMetaclass);
@@ -3935,9 +3957,10 @@
StringRef Section,
CharUnits Align,
bool AddToUsed) {
+ llvm::GlobalValue::LinkageTypes LT =
+ getLinkageTypeForObjCMetadata(CGM, Section);
llvm::GlobalVariable *GV =
- Init.finishAndCreateGlobal(Name, Align, /*constant*/ false,
- llvm::GlobalValue::PrivateLinkage);
+ Init.finishAndCreateGlobal(Name, Align, /*constant*/ false, LT);
if (!Section.empty())
GV->setSection(Section);
if (AddToUsed)
@@ -3951,9 +3974,10 @@
CharUnits Align,
bool AddToUsed) {
llvm::Type *Ty = Init->getType();
+ llvm::GlobalValue::LinkageTypes LT =
+ getLinkageTypeForObjCMetadata(CGM, Section);
llvm::GlobalVariable *GV =
- new llvm::GlobalVariable(CGM.getModule(), Ty, false,
- llvm::GlobalValue::PrivateLinkage, Init, Name);
+ new llvm::GlobalVariable(CGM.getModule(), Ty, false, LT, Init, Name);
if (!Section.empty())
GV->setSection(Section);
GV->setAlignment(Align.getQuantity());
@@ -6000,10 +6024,15 @@
Symbols.size()),
Symbols);
+ // Section name is obtained by calling GetSectionName, which returns
+ // sections in the __DATA segment on MachO.
+ assert((!CGM.getTriple().isOSBinFormatMachO() ||
+ SectionName.startswith("__DATA")) &&
+ "SectionName expected to start with __DATA on MachO");
+ llvm::GlobalValue::LinkageTypes LT =
+ getLinkageTypeForObjCMetadata(CGM, SectionName);
llvm::GlobalVariable *GV =
- new llvm::GlobalVariable(CGM.getModule(), Init->getType(), false,
- llvm::GlobalValue::PrivateLinkage,
- Init,
+ new llvm::GlobalVariable(CGM.getModule(), Init->getType(), false, LT, Init,
SymbolName);
GV->setAlignment(CGM.getDataLayout().getABITypeAlignment(Init->getType()));
GV->setSection(SectionName);
@@ -6182,7 +6211,7 @@
const ObjCInterfaceDecl *OID = ID->getClassInterface();
assert(OID && "CGObjCNonFragileABIMac::BuildClassRoTInitializer");
- values.add(EmitProtocolList("\01l_OBJC_CLASS_PROTOCOLS_$_"
+ values.add(EmitProtocolList("_OBJC_CLASS_PROTOCOLS_$_"
+ OID->getObjCRuntimeNameAsString(),
OID->all_referenced_protocol_begin(),
OID->all_referenced_protocol_end()));
@@ -6191,29 +6220,23 @@
values.addNullPointer(ObjCTypes.IvarListnfABIPtrTy);
values.add(GetIvarLayoutName(nullptr, ObjCTypes));
values.add(EmitPropertyList(
- "\01l_OBJC_$_CLASS_PROP_LIST_" + ID->getObjCRuntimeNameAsString(),
+ "_OBJC_$_CLASS_PROP_LIST_" + ID->getObjCRuntimeNameAsString(),
ID, ID->getClassInterface(), ObjCTypes, true));
} else {
values.add(EmitIvarList(ID));
values.add(BuildWeakIvarLayout(ID, beginInstance, endInstance, hasMRCWeak));
values.add(EmitPropertyList(
- "\01l_OBJC_$_PROP_LIST_" + ID->getObjCRuntimeNameAsString(),
+ "_OBJC_$_PROP_LIST_" + ID->getObjCRuntimeNameAsString(),
ID, ID->getClassInterface(), ObjCTypes, false));
}
llvm::SmallString<64> roLabel;
llvm::raw_svector_ostream(roLabel)
- << ((flags & NonFragileABI_Class_Meta) ? "\01l_OBJC_METACLASS_RO_$_"
- : "\01l_OBJC_CLASS_RO_$_")
+ << ((flags & NonFragileABI_Class_Meta) ? "_OBJC_METACLASS_RO_$_"
+ : "_OBJC_CLASS_RO_$_")
<< ClassName;
- llvm::GlobalVariable *CLASS_RO_GV =
- values.finishAndCreateGlobal(roLabel, CGM.getPointerAlign(),
- /*constant*/ false,
- llvm::GlobalValue::PrivateLinkage);
- if (CGM.getTriple().isOSBinFormatMachO())
- CLASS_RO_GV->setSection("__DATA, __objc_const");
- return CLASS_RO_GV;
+ return finishAndCreateGlobal(values, roLabel, CGM);
}
/// Build the metaclass object for a class.
@@ -6445,7 +6468,7 @@
llvm::ConstantExpr::getBitCast(GetOrEmitProtocol(PD),
ObjCTypes.getExternalProtocolPtrTy());
- std::string ProtocolName("\01l_OBJC_PROTOCOL_REFERENCE_$_");
+ std::string ProtocolName("_OBJC_PROTOCOL_REFERENCE_$_");
ProtocolName += PD->getObjCRuntimeNameAsString();
CharUnits Align = CGF.getPointerAlign();
@@ -6480,7 +6503,7 @@
///
void CGObjCNonFragileABIMac::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
const ObjCInterfaceDecl *Interface = OCD->getClassInterface();
- const char *Prefix = "\01l_OBJC_$_CATEGORY_";
+ const char *Prefix = "_OBJC_$_CATEGORY_";
llvm::SmallString<64> ExtCatName(Prefix);
ExtCatName += Interface->getObjCRuntimeNameAsString();
@@ -6516,14 +6539,14 @@
SmallString<256> ExtName;
llvm::raw_svector_ostream(ExtName) << Interface->getObjCRuntimeNameAsString() << "_$_"
<< OCD->getName();
- values.add(EmitProtocolList("\01l_OBJC_CATEGORY_PROTOCOLS_$_"
+ values.add(EmitProtocolList("_OBJC_CATEGORY_PROTOCOLS_$_"
+ Interface->getObjCRuntimeNameAsString() + "_$_"
+ Category->getName(),
Category->protocol_begin(),
Category->protocol_end()));
- values.add(EmitPropertyList("\01l_OBJC_$_PROP_LIST_" + ExtName.str(),
+ values.add(EmitPropertyList("_OBJC_$_PROP_LIST_" + ExtName.str(),
OCD, Category, ObjCTypes, false));
- values.add(EmitPropertyList("\01l_OBJC_$_CLASS_PROP_LIST_" + ExtName.str(),
+ values.add(EmitPropertyList("_OBJC_$_CLASS_PROP_LIST_" + ExtName.str(),
OCD, Category, ObjCTypes, true));
} else {
values.addNullPointer(ObjCTypes.ProtocolListnfABIPtrTy);
@@ -6535,11 +6558,7 @@
values.addInt(ObjCTypes.IntTy, Size);
llvm::GlobalVariable *GCATV =
- values.finishAndCreateGlobal(ExtCatName.str(), CGM.getPointerAlign(),
- /*constant*/ false,
- llvm::GlobalValue::PrivateLinkage);
- if (CGM.getTriple().isOSBinFormatMachO())
- GCATV->setSection("__DATA, __objc_const");
+ finishAndCreateGlobal(values, ExtCatName.str(), CGM);
CGM.addCompilerUsedGlobal(GCATV);
DefinedCategories.push_back(GCATV);
@@ -6598,36 +6617,36 @@
bool forProtocol;
switch (kind) {
case MethodListType::CategoryInstanceMethods:
- prefix = "\01l_OBJC_$_CATEGORY_INSTANCE_METHODS_";
+ prefix = "_OBJC_$_CATEGORY_INSTANCE_METHODS_";
forProtocol = false;
break;
case MethodListType::CategoryClassMethods:
- prefix = "\01l_OBJC_$_CATEGORY_CLASS_METHODS_";
+ prefix = "_OBJC_$_CATEGORY_CLASS_METHODS_";
forProtocol = false;
break;
case MethodListType::InstanceMethods:
- prefix = "\01l_OBJC_$_INSTANCE_METHODS_";
+ prefix = "_OBJC_$_INSTANCE_METHODS_";
forProtocol = false;
break;
case MethodListType::ClassMethods:
- prefix = "\01l_OBJC_$_CLASS_METHODS_";
+ prefix = "_OBJC_$_CLASS_METHODS_";
forProtocol = false;
break;
case MethodListType::ProtocolInstanceMethods:
- prefix = "\01l_OBJC_$_PROTOCOL_INSTANCE_METHODS_";
+ prefix = "_OBJC_$_PROTOCOL_INSTANCE_METHODS_";
forProtocol = true;
break;
case MethodListType::ProtocolClassMethods:
- prefix = "\01l_OBJC_$_PROTOCOL_CLASS_METHODS_";
+ prefix = "_OBJC_$_PROTOCOL_CLASS_METHODS_";
forProtocol = true;
break;
case MethodListType::OptionalProtocolInstanceMethods:
- prefix = "\01l_OBJC_$_PROTOCOL_INSTANCE_METHODS_OPT_";
+ prefix = "_OBJC_$_PROTOCOL_INSTANCE_METHODS_OPT_";
forProtocol = true;
break;
case MethodListType::OptionalProtocolClassMethods:
- prefix = "\01l_OBJC_$_PROTOCOL_CLASS_METHODS_OPT_";
+ prefix = "_OBJC_$_PROTOCOL_CLASS_METHODS_OPT_";
forProtocol = true;
break;
}
@@ -6646,11 +6665,7 @@
}
methodArray.finishAndAddTo(values);
- auto *GV = values.finishAndCreateGlobal(prefix + name, CGM.getPointerAlign(),
- /*constant*/ false,
- llvm::GlobalValue::PrivateLinkage);
- if (CGM.getTriple().isOSBinFormatMachO())
- GV->setSection("__DATA, __objc_const");
+ llvm::GlobalVariable *GV = finishAndCreateGlobal(values, prefix + name, CGM);
CGM.addCompilerUsedGlobal(GV);
return llvm::ConstantExpr::getBitCast(GV, ObjCTypes.MethodListnfABIPtrTy);
}
@@ -6790,13 +6805,9 @@
ivars.finishAndAddTo(ivarList);
ivarList.fillPlaceholderWithInt(ivarCountSlot, ObjCTypes.IntTy, ivarCount);
- const char *Prefix = "\01l_OBJC_$_INSTANCE_VARIABLES_";
- llvm::GlobalVariable *GV =
- ivarList.finishAndCreateGlobal(Prefix + OID->getObjCRuntimeNameAsString(),
- CGM.getPointerAlign(), /*constant*/ false,
- llvm::GlobalValue::PrivateLinkage);
- if (CGM.getTriple().isOSBinFormatMachO())
- GV->setSection("__DATA, __objc_const");
+ const char *Prefix = "_OBJC_$_INSTANCE_VARIABLES_";
+ llvm::GlobalVariable *GV = finishAndCreateGlobal(
+ ivarList, Prefix + OID->getObjCRuntimeNameAsString(), CGM);
CGM.addCompilerUsedGlobal(GV);
return llvm::ConstantExpr::getBitCast(GV, ObjCTypes.IvarListnfABIPtrTy);
}
@@ -6864,7 +6875,7 @@
// isa is NULL
values.addNullPointer(ObjCTypes.ObjectPtrTy);
values.add(GetClassName(PD->getObjCRuntimeNameAsString()));
- values.add(EmitProtocolList("\01l_OBJC_$_PROTOCOL_REFS_"
+ values.add(EmitProtocolList("_OBJC_$_PROTOCOL_REFS_"
+ PD->getObjCRuntimeNameAsString(),
PD->protocol_begin(),
PD->protocol_end()));
@@ -6877,13 +6888,13 @@
values.add(methodLists.emitMethodList(this, PD,
ProtocolMethodLists::OptionalClassMethods));
values.add(EmitPropertyList(
- "\01l_OBJC_$_PROP_LIST_" + PD->getObjCRuntimeNameAsString(),
+ "_OBJC_$_PROP_LIST_" + PD->getObjCRuntimeNameAsString(),
nullptr, PD, ObjCTypes, false));
uint32_t Size =
CGM.getDataLayout().getTypeAllocSize(ObjCTypes.ProtocolnfABITy);
values.addInt(ObjCTypes.IntTy, Size);
values.addInt(ObjCTypes.IntTy, 0);
- values.add(EmitProtocolMethodTypes("\01l_OBJC_$_PROTOCOL_METHOD_TYPES_"
+ values.add(EmitProtocolMethodTypes("_OBJC_$_PROTOCOL_METHOD_TYPES_"
+ PD->getObjCRuntimeNameAsString(),
methodLists.emitExtendedTypesArray(this),
ObjCTypes));
@@ -6892,7 +6903,7 @@
values.addNullPointer(ObjCTypes.Int8PtrTy);
values.add(EmitPropertyList(
- "\01l_OBJC_$_CLASS_PROP_LIST_" + PD->getObjCRuntimeNameAsString(),
+ "_OBJC_$_CLASS_PROP_LIST_" + PD->getObjCRuntimeNameAsString(),
nullptr, PD, ObjCTypes, true));
if (Entry) {
@@ -6976,11 +6987,7 @@
array.finishAndAddTo(values);
values.fillPlaceholderWithInt(countSlot, ObjCTypes.LongTy, count);
- GV = values.finishAndCreateGlobal(Name, CGM.getPointerAlign(),
- /*constant*/ false,
- llvm::GlobalValue::PrivateLinkage);
- if (CGM.getTriple().isOSBinFormatMachO())
- GV->setSection("__DATA, __objc_const");
+ GV = finishAndCreateGlobal(values, Name, CGM);
CGM.addCompilerUsedGlobal(GV);
return llvm::ConstantExpr::getBitCast(GV,
ObjCTypes.ProtocolListnfABIPtrTy);
@@ -7091,7 +7098,7 @@
// except normal, non-super message-sends.
// FIXME: don't use this for that.
llvm::FunctionCallee fn = nullptr;
- std::string messageRefName("\01l_");
+ std::string messageRefName("_");
if (CGM.ReturnSlotInterferesWithArgs(MSI.CallInfo)) {
if (isSuper) {
fn = ObjCTypes.getMessageSendSuper2StretFixupFn();
@@ -7245,12 +7252,14 @@
NotForDefinition);
}
- Entry = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassnfABIPtrTy,
- false, llvm::GlobalValue::PrivateLinkage,
- ClassGV, "OBJC_CLASSLIST_REFERENCES_$_");
+ std::string SectionName =
+ GetSectionName("__objc_classrefs", "regular,no_dead_strip");
+ Entry = new llvm::GlobalVariable(
+ CGM.getModule(), ObjCTypes.ClassnfABIPtrTy, false,
+ getLinkageTypeForObjCMetadata(CGM, SectionName), ClassGV,
+ "OBJC_CLASSLIST_REFERENCES_$_");
Entry->setAlignment(Align.getQuantity());
- Entry->setSection(GetSectionName("__objc_classrefs",
- "regular,no_dead_strip"));
+ Entry->setSection(SectionName);
CGM.addCompilerUsedGlobal(Entry);
}
return CGF.Builder.CreateAlignedLoad(Entry, Align);
@@ -7280,12 +7289,14 @@
if (!Entry) {
auto ClassGV = GetClassGlobal(ID, /*metaclass*/ false, NotForDefinition);
- Entry = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassnfABIPtrTy,
- false, llvm::GlobalValue::PrivateLinkage,
- ClassGV, "OBJC_CLASSLIST_SUP_REFS_$_");
+ std::string SectionName =
+ GetSectionName("__objc_superrefs", "regular,no_dead_strip");
+ Entry = new llvm::GlobalVariable(
+ CGM.getModule(), ObjCTypes.ClassnfABIPtrTy, false,
+ getLinkageTypeForObjCMetadata(CGM, SectionName), ClassGV,
+ "OBJC_CLASSLIST_SUP_REFS_$_");
Entry->setAlignment(Align.getQuantity());
- Entry->setSection(GetSectionName("__objc_superrefs",
- "regular,no_dead_strip"));
+ Entry->setSection(SectionName);
CGM.addCompilerUsedGlobal(Entry);
}
return CGF.Builder.CreateAlignedLoad(Entry, Align);
@@ -7301,14 +7312,14 @@
llvm::GlobalVariable * &Entry = MetaClassReferences[ID->getIdentifier()];
if (!Entry) {
auto MetaClassGV = GetClassGlobal(ID, /*metaclass*/ true, NotForDefinition);
-
- Entry = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ClassnfABIPtrTy,
- false, llvm::GlobalValue::PrivateLinkage,
- MetaClassGV, "OBJC_CLASSLIST_SUP_REFS_$_");
+ std::string SectionName =
+ GetSectionName("__objc_superrefs", "regular,no_dead_strip");
+ Entry = new llvm::GlobalVariable(
+ CGM.getModule(), ObjCTypes.ClassnfABIPtrTy, false,
+ getLinkageTypeForObjCMetadata(CGM, SectionName), MetaClassGV,
+ "OBJC_CLASSLIST_SUP_REFS_$_");
Entry->setAlignment(Align.getQuantity());
-
- Entry->setSection(GetSectionName("__objc_superrefs",
- "regular,no_dead_strip"));
+ Entry->setSection(SectionName);
CGM.addCompilerUsedGlobal(Entry);
}
@@ -7398,12 +7409,14 @@
llvm::Constant *Casted =
llvm::ConstantExpr::getBitCast(GetMethodVarName(Sel),
ObjCTypes.SelectorPtrTy);
- Entry = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.SelectorPtrTy,
- false, llvm::GlobalValue::PrivateLinkage,
- Casted, "OBJC_SELECTOR_REFERENCES_");
+ std::string SectionName =
+ GetSectionName("__objc_selrefs", "literal_pointers,no_dead_strip");
+ Entry = new llvm::GlobalVariable(
+ CGM.getModule(), ObjCTypes.SelectorPtrTy, false,
+ getLinkageTypeForObjCMetadata(CGM, SectionName), Casted,
+ "OBJC_SELECTOR_REFERENCES_");
Entry->setExternallyInitialized(true);
- Entry->setSection(GetSectionName("__objc_selrefs",
- "literal_pointers,no_dead_strip"));
+ Entry->setSection(SectionName);
Entry->setAlignment(Align.getQuantity());
CGM.addCompilerUsedGlobal(Entry);
}