CGDecl::emitStoresForConstant fix synthesized constant's name

Summary: The name of the synthesized constants for constant initialization was using mangling for statics, which isn't generally correct and (in a yet-uncommitted patch) causes the mangler to assert out because the static ends up trying to mangle function parameters and this makes no sense. Instead, mangle to `"__const." + FunctionName + "." + DeclName`.

Reviewers: rjmccall

Subscribers: dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D54055

llvm-svn: 346915

1 files changed, 47 insertions, 19 deletions

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 4230dbdf293..176152a8369 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -963,6 +963,49 @@ static llvm::Value *shouldUseMemSetToInitialize(llvm::Constant *Init,
   return llvm::isBytewiseValue(Init);
 }
 
+static Address createUnnamedGlobalFrom(CodeGenModule &CGM, const VarDecl &D,
+                                       CGBuilderTy &Builder,
+                                       llvm::Constant *Constant,
+                                       CharUnits Align) {
+  auto FunctionName = [&](const DeclContext *DC) -> std::string {
+    if (const auto *FD = dyn_cast<FunctionDecl>(DC)) {
+      if (const auto *CC = dyn_cast<CXXConstructorDecl>(FD))
+        return CC->getNameAsString();
+      if (const auto *CD = dyn_cast<CXXDestructorDecl>(FD))
+        return CD->getNameAsString();
+      return CGM.getMangledName(FD);
+    } else if (const auto *OM = dyn_cast<ObjCMethodDecl>(DC)) {
+      return OM->getNameAsString();
+    } else if (const auto *OM = dyn_cast<BlockDecl>(DC)) {
+      return "<block>";
+    } else if (const auto *OM = dyn_cast<CapturedDecl>(DC)) {
+      return "<captured>";
+    } else {
+      llvm::llvm_unreachable_internal("expected a function or method");
+    }
+  };
+
+  auto *Ty = Constant->getType();
+  bool isConstant = true;
+  llvm::GlobalVariable *InsertBefore = nullptr;
+  unsigned AS = CGM.getContext().getTargetAddressSpace(
+      CGM.getStringLiteralAddressSpace());
+  llvm::GlobalVariable *GV = new llvm::GlobalVariable(
+      CGM.getModule(), Ty, isConstant, llvm::GlobalValue::PrivateLinkage,
+      Constant,
+      "__const." + FunctionName(D.getParentFunctionOrMethod()) + "." +
+          D.getName(),
+      InsertBefore, llvm::GlobalValue::NotThreadLocal, AS);
+  GV->setAlignment(Align.getQuantity());
+  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+
+  Address SrcPtr = Address(GV, Align);
+  llvm::Type *BP = llvm::PointerType::getInt8PtrTy(CGM.getLLVMContext(), AS);
+  if (SrcPtr.getType() != BP)
+    SrcPtr = Builder.CreateBitCast(SrcPtr, BP);
+  return SrcPtr;
+}
+
 static void emitStoresForConstant(CodeGenModule &CGM, const VarDecl &D,
                                   Address Loc, bool isVolatile,
                                   CGBuilderTy &Builder,
@@ -1002,25 +1045,10 @@ static void emitStoresForConstant(CodeGenModule &CGM, const VarDecl &D,
     return;
   }
 
-  // Otherwise, create a temporary global with the initializer then memcpy from
-  // the global to the alloca.
-  std::string Name = getStaticDeclName(CGM, D);
-  unsigned AS = CGM.getContext().getTargetAddressSpace(
-      CGM.getStringLiteralAddressSpace());
-  llvm::Type *BP = llvm::PointerType::getInt8PtrTy(CGM.getLLVMContext(), AS);
-
-  llvm::GlobalVariable *GV = new llvm::GlobalVariable(
-      CGM.getModule(), constant->getType(), true,
-      llvm::GlobalValue::PrivateLinkage, constant, Name, nullptr,
-      llvm::GlobalValue::NotThreadLocal, AS);
-  GV->setAlignment(Loc.getAlignment().getQuantity());
-  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-
-  Address SrcPtr = Address(GV, Loc.getAlignment());
-  if (SrcPtr.getType() != BP)
-    SrcPtr = Builder.CreateBitCast(SrcPtr, BP);
-
-  Builder.CreateMemCpy(Loc, SrcPtr, SizeVal, isVolatile);
+  Builder.CreateMemCpy(
+      Loc,
+      createUnnamedGlobalFrom(CGM, D, Builder, constant, Loc.getAlignment()),
+      SizeVal, isVolatile);
 }
 
 /// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a