[PATCH] Mangle predefined string constants names to merge them at link-time

[Alexey Samsonov]

Hi majnemer,

This change generalizes the code used to create global LLVM
variables referencing predefined strings (e.g. __FUNCTION__): now it
just calls GetAddrOfConstantStringFromLiteral method. As a result,
global variables for these predefined strings may get mangled names
and linkonce_odr linkage. Fix the test accordingly.

http://reviews.llvm.org/D4023

Files:
  lib/CodeGen/CGExpr.cpp
  test/CodeGenCXX/ms_wide_predefined_expr.cpp

Index: test/CodeGenCXX/ms_wide_predefined_expr.cpp
===================================================================
--- test/CodeGenCXX/ms_wide_predefined_expr.cpp
+++ test/CodeGenCXX/ms_wide_predefined_expr.cpp
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 %s -fms-extensions -triple i686-pc-win32 -emit-llvm -o - | FileCheck %s
 
-// CHECK: @"L__FUNCTION__.?func@@YAXXZ" = private constant [5 x i16] [i16 102, i16 117, i16 110, i16 99, i16 0], align 2
+// CHECK: @"\01??_C at _19DPFBEKIN@?$AAf?$AAu?$AAn?$AAc?$AA?$AA@" = linkonce_odr unnamed_addr constant [5 x i16] [i16 102, i16 117, i16 110, i16 99, i16 0], align 2
 
 void wprint(const wchar_t*);
 
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -1968,28 +1968,6 @@
                         E->getType());
 }
 
-static llvm::Constant*
-GetAddrOfConstantWideString(StringRef Str,
-                            const char *GlobalName,
-                            ASTContext &Context,
-                            QualType Ty, SourceLocation Loc,
-                            CodeGenModule &CGM) {
-
-  StringLiteral *SL = StringLiteral::Create(Context,
-                                            Str,
-                                            StringLiteral::Wide,
-                                            /*Pascal = */false,
-                                            Ty, Loc);
-  llvm::Constant *C = CGM.GetConstantArrayFromStringLiteral(SL);
-  auto *GV = new llvm::GlobalVariable(
-      CGM.getModule(), C->getType(), !CGM.getLangOpts().WritableStrings,
-      llvm::GlobalValue::PrivateLinkage, C, GlobalName);
-  const unsigned WideAlignment =
-    Context.getTypeAlignInChars(Ty).getQuantity();
-  GV->setAlignment(WideAlignment);
-  return GV;
-}
-
 static void ConvertUTF8ToWideString(unsigned CharByteWidth, StringRef Source,
                                     SmallString<32>& Target) {
   Target.resize(CharByteWidth * (Source.size() + 1));
@@ -2058,14 +2036,12 @@
     if (ElemType->isWideCharType()) {
       SmallString<32> RawChars;
       ConvertUTF8ToWideString(
-          getContext().getTypeSizeInChars(ElemType).getQuantity(),
-          FunctionName, RawChars);
-      C = GetAddrOfConstantWideString(RawChars,
-                                      GVName.c_str(),
-                                      getContext(),
-                                      E->getType(),
-                                      E->getLocation(),
-                                      CGM);
+          getContext().getTypeSizeInChars(ElemType).getQuantity(), FunctionName,
+          RawChars);
+      StringLiteral *SL = StringLiteral::Create(
+          getContext(), RawChars, StringLiteral::Wide,
+          /*Pascal = */ false, E->getType(), E->getLocation());
+      C = CGM.GetAddrOfConstantStringFromLiteral(SL);
     } else {
       C = CGM.GetAddrOfConstantCString(FunctionName, GVName.c_str(), 1);
     }
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D4023.10104.patch
Type: text/x-patch
Size: 2986 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20140604/8fd4d82f/attachment.bin>