PR20473: Don't "deduplicate" string literals with the same value but different
lengths! In passing, simplify string literal deduplication by relying on LLVM
to deduplicate the underlying constant values.
llvm-svn: 214222
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index bd7acf9..48823be 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2773,10 +2773,11 @@
auto Alignment =
getContext().getAlignOfGlobalVarInChars(S->getType()).getQuantity();
- llvm::StringMapEntry<llvm::GlobalVariable *> *Entry = nullptr;
+ llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
+ llvm::GlobalVariable **Entry = nullptr;
if (!LangOpts.WritableStrings) {
- Entry = getConstantStringMapEntry(S->getBytes(), S->getCharByteWidth());
- if (auto GV = Entry->getValue()) {
+ Entry = &ConstantStringMap[C];
+ if (auto GV = *Entry) {
if (Alignment > GV->getAlignment())
GV->setAlignment(Alignment);
return GV;
@@ -2803,10 +2804,9 @@
GlobalVariableName = ".str";
}
- llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
if (Entry)
- Entry->setValue(GV);
+ *Entry = GV;
reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>");
return GV;
@@ -2822,26 +2822,6 @@
return GetAddrOfConstantCString(Str);
}
-
-llvm::StringMapEntry<llvm::GlobalVariable *> *CodeGenModule::getConstantStringMapEntry(
- StringRef Str, int CharByteWidth) {
- llvm::StringMap<llvm::GlobalVariable *> *ConstantStringMap = nullptr;
- switch (CharByteWidth) {
- case 1:
- ConstantStringMap = &Constant1ByteStringMap;
- break;
- case 2:
- ConstantStringMap = &Constant2ByteStringMap;
- break;
- case 4:
- ConstantStringMap = &Constant4ByteStringMap;
- break;
- default:
- llvm_unreachable("unhandled byte width!");
- }
- return &ConstantStringMap->GetOrCreateValue(Str);
-}
-
/// GetAddrOfConstantCString - Returns a pointer to a character array containing
/// the literal and a terminating '\0' character.
/// The result has pointer to array type.
@@ -2854,19 +2834,20 @@
.getQuantity();
}
+ llvm::Constant *C =
+ llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
+
// Don't share any string literals if strings aren't constant.
- llvm::StringMapEntry<llvm::GlobalVariable *> *Entry = nullptr;
+ llvm::GlobalVariable **Entry = nullptr;
if (!LangOpts.WritableStrings) {
- Entry = getConstantStringMapEntry(StrWithNull, 1);
- if (auto GV = Entry->getValue()) {
+ Entry = &ConstantStringMap[C];
+ if (auto GV = *Entry) {
if (Alignment > GV->getAlignment())
GV->setAlignment(Alignment);
return GV;
}
}
- llvm::Constant *C =
- llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
// Get the default prefix if a name wasn't specified.
if (!GlobalName)
GlobalName = ".str";
@@ -2874,7 +2855,7 @@
auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
GlobalName, Alignment);
if (Entry)
- Entry->setValue(GV);
+ *Entry = GV;
return GV;
}
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 44597bf..9533a8d 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -361,9 +361,7 @@
llvm::StringMap<llvm::Constant*> CFConstantStringMap;
- llvm::StringMap<llvm::GlobalVariable *> Constant1ByteStringMap;
- llvm::StringMap<llvm::GlobalVariable *> Constant2ByteStringMap;
- llvm::StringMap<llvm::GlobalVariable *> Constant4ByteStringMap;
+ llvm::DenseMap<llvm::Constant *, llvm::GlobalVariable *> ConstantStringMap;
llvm::DenseMap<const Decl*, llvm::Constant *> StaticLocalDeclMap;
llvm::DenseMap<const Decl*, llvm::GlobalVariable*> StaticLocalDeclGuardMap;
llvm::DenseMap<const Expr*, llvm::Constant *> MaterializedGlobalTemporaryMap;
@@ -1044,9 +1042,6 @@
llvm::PointerType *PTy,
const VarDecl *D);
- llvm::StringMapEntry<llvm::GlobalVariable *> *
- getConstantStringMapEntry(StringRef Str, int CharByteWidth);
-
/// Set attributes which are common to any form of a global definition (alias,
/// Objective-C method, function, global variable).
///