CodeGen: refactor the ObjC cstring literal creation

This refactors the cstring literal creation as mentioned in the couple of FIXMEs
littered in the various invocations to CreateMetadataVar.  This centralises the
definition of the literals, and will enable changing the literal creation to a
single site.  NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@281798 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 97e9925fcd86b3f95c8d50187e28930156df8949..fad36f6232aff6ea4ac63d7693f042b8d6e6fffb 100644 (file)
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -733,6 +733,13 @@ public:
   ObjCNonFragileABITypesHelper(CodeGen::CodeGenModule &cgm);
 };
 
+enum class ObjCLabelType {
+  ClassName,
+  MethodVarName,
+  MethodVarType,
+  PropertyName,
+};
+
 class CGObjCCommonMac : public CodeGen::CGObjCRuntime {
 public:
   class SKIP_SCAN {
@@ -1018,6 +1025,9 @@ public:
                                           StringRef Section, CharUnits Align,
                                           bool AddToUsed);
 
+  llvm::GlobalVariable *CreateCStringLiteral(StringRef Name,
+                                             ObjCLabelType LabelType);
+
 protected:
   CodeGen::RValue EmitMessageSend(CodeGen::CodeGenFunction &CGF,
                                   ReturnValueSlot Return,
@@ -3650,6 +3660,46 @@ llvm::GlobalVariable *CGObjCCommonMac::CreateMetadataVar(Twine Name,
   return GV;
 }
 
+llvm::GlobalVariable *
+CGObjCCommonMac::CreateCStringLiteral(StringRef Name, ObjCLabelType Type) {
+  StringRef Label;
+  switch (Type) {
+  case ObjCLabelType::ClassName:     Label = "OBJC_CLASS_NAME_"; break;
+  case ObjCLabelType::MethodVarName: Label = "OBJC_METH_VAR_NAME_"; break;
+  case ObjCLabelType::MethodVarType: Label = "OBJC_METH_VAR_TYPE_"; break;
+  case ObjCLabelType::PropertyName:  Label = "OBJC_PROP_NAME_ATTR_"; break;
+  }
+
+  StringRef Section;
+  switch (Type) {
+  case ObjCLabelType::ClassName:
+    Section = isNonFragileABI() ? "__TEXT,__objc_classname,cstring_literals"
+                                : "__TEXT,__cstring,cstring_literals";
+    break;
+  case ObjCLabelType::MethodVarName:
+    Section = isNonFragileABI() ? "__TEXT,__objc_methname,cstring_literals"
+                                : "__TEXT,__cstring,cstring_literals";
+    break;
+  case ObjCLabelType::MethodVarType:
+    Section = isNonFragileABI() ? "__TEXT,__objc_methtype,cstring_literals"
+                                : "__TEXT,__cstring,cstring_literals";
+    break;
+  case ObjCLabelType::PropertyName:
+    Section = "__TEXT,__cstring,cstring_literals";
+    break;
+  }
+
+  llvm::Constant *Value = llvm::ConstantDataArray::getString(VMContext, Name);
+  llvm::GlobalVariable *GV =
+      new llvm::GlobalVariable(CGM.getModule(), Value->getType(), false,
+                               llvm::GlobalValue::PrivateLinkage, Value, Label);
+  GV->setSection(Section);
+  GV->setAlignment(CharUnits::One().getQuantity());
+  CGM.addCompilerUsedGlobal(GV);
+
+  return GV;
+}
+
 llvm::Function *CGObjCMac::ModuleInitFunction() {
   // Abuse this interface function as a place to finalize.
   FinishModule();
@@ -4707,12 +4757,7 @@ Address CGObjCMac::EmitSelectorAddr(CodeGenFunction &CGF, Selector Sel) {
 llvm::Constant *CGObjCCommonMac::GetClassName(StringRef RuntimeName) {
     llvm::GlobalVariable *&Entry = ClassNames[RuntimeName];
     if (!Entry)
-      Entry = CreateMetadataVar(
-          "OBJC_CLASS_NAME_",
-          llvm::ConstantDataArray::getString(VMContext, RuntimeName),
-          ((ObjCABI == 2) ? "__TEXT,__objc_classname,cstring_literals"
-                          : "__TEXT,__cstring,cstring_literals"),
-          CharUnits::One(), true);
+      Entry = CreateCStringLiteral(RuntimeName, ObjCLabelType::ClassName);
     return getConstantGEP(VMContext, Entry, 0, 0);
 }
 
@@ -4960,14 +5005,8 @@ llvm::Constant *IvarLayoutBuilder::buildBitmap(CGObjCCommonMac &CGObjC,
   // Null terminate the string.
   buffer.push_back(0);
 
-  bool isNonFragileABI = CGObjC.isNonFragileABI();
-
-  llvm::GlobalVariable *Entry = CGObjC.CreateMetadataVar(
-      "OBJC_CLASS_NAME_",
-      llvm::ConstantDataArray::get(CGM.getLLVMContext(), buffer),
-      (isNonFragileABI ? "__TEXT,__objc_classname,cstring_literals"
-                       : "__TEXT,__cstring,cstring_literals"),
-      CharUnits::One(), true);
+  auto *Entry = CGObjC.CreateCStringLiteral(
+      reinterpret_cast<char *>(buffer.data()), ObjCLabelType::ClassName);
   return getConstantGEP(CGM.getLLVMContext(), Entry, 0, 0);
 }
 
@@ -5062,16 +5101,9 @@ CGObjCCommonMac::BuildIvarLayout(const ObjCImplementationDecl *OMD,
 
 llvm::Constant *CGObjCCommonMac::GetMethodVarName(Selector Sel) {
   llvm::GlobalVariable *&Entry = MethodVarNames[Sel];
-
   // FIXME: Avoid std::string in "Sel.getAsString()"
   if (!Entry)
-    Entry = CreateMetadataVar(
-        "OBJC_METH_VAR_NAME_",
-        llvm::ConstantDataArray::getString(VMContext, Sel.getAsString()),
-        ((ObjCABI == 2) ? "__TEXT,__objc_methname,cstring_literals"
-                        : "__TEXT,__cstring,cstring_literals"),
-        CharUnits::One(), true);
-
+    Entry = CreateCStringLiteral(Sel.getAsString(), ObjCLabelType::MethodVarName);
   return getConstantGEP(VMContext, Entry, 0, 0);
 }
 
@@ -5085,15 +5117,8 @@ llvm::Constant *CGObjCCommonMac::GetMethodVarType(const FieldDecl *Field) {
   CGM.getContext().getObjCEncodingForType(Field->getType(), TypeStr, Field);
 
   llvm::GlobalVariable *&Entry = MethodVarTypes[TypeStr];
-
   if (!Entry)
-    Entry = CreateMetadataVar(
-        "OBJC_METH_VAR_TYPE_",
-        llvm::ConstantDataArray::getString(VMContext, TypeStr),
-        ((ObjCABI == 2) ? "__TEXT,__objc_methtype,cstring_literals"
-                        : "__TEXT,__cstring,cstring_literals"),
-        CharUnits::One(), true);
-
+    Entry = CreateCStringLiteral(TypeStr, ObjCLabelType::MethodVarType);
   return getConstantGEP(VMContext, Entry, 0, 0);
 }
 
@@ -5104,28 +5129,16 @@ llvm::Constant *CGObjCCommonMac::GetMethodVarType(const ObjCMethodDecl *D,
     return nullptr;
 
   llvm::GlobalVariable *&Entry = MethodVarTypes[TypeStr];
-
   if (!Entry)
-    Entry = CreateMetadataVar(
-        "OBJC_METH_VAR_TYPE_",
-        llvm::ConstantDataArray::getString(VMContext, TypeStr),
-        ((ObjCABI == 2) ? "__TEXT,__objc_methtype,cstring_literals"
-                        : "__TEXT,__cstring,cstring_literals"),
-        CharUnits::One(), true);
-
+    Entry = CreateCStringLiteral(TypeStr, ObjCLabelType::MethodVarType);
   return getConstantGEP(VMContext, Entry, 0, 0);
 }
 
 // FIXME: Merge into a single cstring creation function.
 llvm::Constant *CGObjCCommonMac::GetPropertyName(IdentifierInfo *Ident) {
   llvm::GlobalVariable *&Entry = PropertyNames[Ident];
-
   if (!Entry)
-    Entry = CreateMetadataVar(
-        "OBJC_PROP_NAME_ATTR_",
-        llvm::ConstantDataArray::getString(VMContext, Ident->getName()),
-        "__TEXT,__cstring,cstring_literals", CharUnits::One(), true);
-
+    Entry = CreateCStringLiteral(Ident->getName(), ObjCLabelType::PropertyName);
   return getConstantGEP(VMContext, Entry, 0, 0);
 }