Just disable the hidden-visibility optimization for now by hiding it behind

a -cc1 option.  The Darwin linker complains about mixed visibility when linking
gcc-built objects with clang-built objects, and the optimization isn't really
that valuable.  Platforms with less ornery linkers can feel free to enable this.

llvm-svn: 110979

4 files changed, 17 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CGRTTI.cpp b/clang/lib/CodeGen/CGRTTI.cpp
index 69171419b66..a3ab6bad8fa 100644
--- a/clang/lib/CodeGen/CGRTTI.cpp
+++ b/clang/lib/CodeGen/CGRTTI.cpp
@@ -11,9 +11,11 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/AST/Type.h"
-#include "clang/AST/RecordLayout.h"
 #include "CodeGenModule.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/AST/Type.h"
+#include "clang/Frontend/CodeGenOptions.h"
+
 using namespace clang;
 using namespace CodeGen;
 
@@ -623,10 +625,13 @@ llvm::Constant *RTTIBuilder::BuildTypeInfo(QualType Ty, bool Force) {
 
   // GCC only relies on the uniqueness of the type names, not the
   // type_infos themselves, so we can emit these as hidden symbols.
+  // But don't do this if we're worried about strict visibility
+  // compatibility.
   if (const RecordType *RT = dyn_cast<RecordType>(Ty))
     CGM.setTypeVisibility(GV, cast<CXXRecordDecl>(RT->getDecl()),
                           /*ForRTTI*/ true);
-  else if (Linkage == llvm::GlobalValue::WeakODRLinkage)
+  else if (CGM.getCodeGenOpts().HiddenWeakVTables &&
+           Linkage == llvm::GlobalValue::WeakODRLinkage)
     GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
   
   return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 494176a9063..22701c2f695 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -2465,6 +2465,9 @@ static void setThunkVisibility(CodeGenModule &CGM, const CXXMethodDecl *MD,
                                const ThunkInfo &Thunk, llvm::Function *Fn) {
   CGM.setGlobalVisibility(Fn, MD);
 
+  if (!CGM.getCodeGenOpts().HiddenWeakVTables)
+    return;
+
   // If the thunk has weak/linkonce linkage, but the function must be
   // emitted in every translation unit that references it, then we can
   // emit its thunks with hidden visibility, since its thunks must be
@@ -2491,7 +2494,7 @@ static void setThunkVisibility(CodeGenModule &CGM, const CXXMethodDecl *MD,
 
   case TSK_ExplicitSpecialization:
   case TSK_ImplicitInstantiation:
-    if (!CGM.getCodeGenOpts().EmitWeakTemplatesHidden)
+    if (!CGM.getCodeGenOpts().HiddenWeakTemplateVTables)
       return;
     break;
   }
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 6283b744c3e..17150426917 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -225,6 +225,9 @@ void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV,
                                       bool IsForRTTI) const {
   setGlobalVisibility(GV, RD);
 
+  if (!CodeGenOpts.HiddenWeakVTables)
+    return;
+
   // We want to drop the visibility to hidden for weak type symbols.
   // This isn't possible if there might be unresolved references
   // elsewhere that rely on this symbol being visible.
@@ -260,7 +263,7 @@ void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV,
   // to deal with mixed-visibility symbols.
   case TSK_ExplicitSpecialization:
   case TSK_ImplicitInstantiation:
-    if (!CodeGenOpts.EmitWeakTemplatesHidden)
+    if (!CodeGenOpts.HiddenWeakTemplateVTables)
       return;
     break;
   }
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 2756c0784ad..4ed4b07565d 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -845,6 +845,7 @@ static void ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
   Opts.DebugPass = Args.getLastArgValue(OPT_mdebug_pass);
   Opts.DisableFPElim = Args.hasArg(OPT_mdisable_fp_elim);
   Opts.FloatABI = Args.getLastArgValue(OPT_mfloat_abi);
+  Opts.HiddenWeakVTables = Args.hasArg(OPT_fhidden_weak_vtables);
   Opts.LimitFloatPrecision = Args.getLastArgValue(OPT_mlimit_float_precision);
   Opts.NoZeroInitializedInBSS = Args.hasArg(OPT_mno_zero_initialized_in_bss);
   Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);