Produce .weak_def_can_be_hidden for some linkonce_odr values

[oota-llvm.git] / lib / CodeGen / AsmPrinter / AsmPrinter.cpp

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index e2bd61f419d426ad3ceed1e66cffffa268e23a11..9a024621651408b35d26f411d2a02826782a5328 100644 (file)
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -48,6 +48,7 @@
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Transforms/Utils/GlobalStatus.h"
 using namespace llvm;
 
 static const char *const DWARFGroupName = "DWARF Emission";
@@ -164,7 +165,7 @@ bool AsmPrinter::doInitialization(Module &M) {
 
   OutStreamer.InitStreamer();
 
-  Mang = new Mangler(OutContext, &TM);
+  Mang = new Mangler(&TM);
 
   // Allow the target to emit any magic that it wants at the start of the file.
   EmitStartOfAsmFile(M);
@@ -212,9 +213,8 @@ bool AsmPrinter::doInitialization(Module &M) {
   llvm_unreachable("Unknown exception type.");
 }
 
-void AsmPrinter::EmitLinkage(unsigned L, MCSymbol *GVSym) const {
-  GlobalValue::LinkageTypes Linkage = (GlobalValue::LinkageTypes)L;
-
+void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
+  GlobalValue::LinkageTypes Linkage = GV->getLinkage();
   switch (Linkage) {
   case GlobalValue::CommonLinkage:
   case GlobalValue::LinkOnceAnyLinkage:
@@ -227,7 +227,20 @@ void AsmPrinter::EmitLinkage(unsigned L, MCSymbol *GVSym) const {
       // .globl _foo
       OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
 
-      if (Linkage != GlobalValue::LinkOnceODRAutoHideLinkage)
+
+      bool CanBeHidden = Linkage == GlobalValue::LinkOnceODRAutoHideLinkage;
+
+      if (!CanBeHidden && Linkage == GlobalValue::LinkOnceODRLinkage) {
+        if (GV->hasUnnamedAddr()) {
+          CanBeHidden = true;
+        } else {
+          GlobalStatus GS;
+          if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared)
+            CanBeHidden = true;
+        }
+      }
+
+      if (!CanBeHidden)
         // .weak_definition _foo
         OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
       else
@@ -263,6 +276,9 @@ void AsmPrinter::EmitLinkage(unsigned L, MCSymbol *GVSym) const {
   llvm_unreachable("Unknown linkage type!");
 }
 
+MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
+  return getObjFileLowering().getSymbol(*Mang, GV);
+}
 
 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
@@ -278,7 +294,7 @@ void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
     }
   }
 
-  MCSymbol *GVSym = Mang->getSymbol(GV);
+  MCSymbol *GVSym = getSymbol(GV);
   EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
 
   if (!GV->hasInitializer())   // External globals require no extra code.
@@ -396,7 +412,7 @@ void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
 
     OutStreamer.SwitchSection(TLVSect);
     // Emit the linkage here.
-    EmitLinkage(GV->getLinkage(), GVSym);
+    EmitLinkage(GV, GVSym);
     OutStreamer.EmitLabel(GVSym);
 
     // Three pointers in size:
@@ -415,7 +431,7 @@ void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
 
   OutStreamer.SwitchSection(TheSection);
 
-  EmitLinkage(GV->getLinkage(), GVSym);
+  EmitLinkage(GV, GVSym);
   EmitAlignment(AlignLog, GV);
 
   OutStreamer.EmitLabel(GVSym);
@@ -441,7 +457,7 @@ void AsmPrinter::EmitFunctionHeader() {
   OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
   EmitVisibility(CurrentFnSym, F->getVisibility());
 
-  EmitLinkage(F->getLinkage(), CurrentFnSym);
+  EmitLinkage(F, CurrentFnSym);
   EmitAlignment(MF->getAlignment(), F);
 
   if (MAI->hasDotTypeDotSizeDirective())
@@ -879,7 +895,7 @@ bool AsmPrinter::doFinalization(Module &M) {
     if (V == GlobalValue::DefaultVisibility)
       continue;
 
-    MCSymbol *Name = Mang->getSymbol(&F);
+    MCSymbol *Name = getSymbol(&F);
     EmitVisibility(Name, V, false);
   }
 
@@ -919,12 +935,12 @@ bool AsmPrinter::doFinalization(Module &M) {
     for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
          I != E; ++I) {
       if (!I->hasExternalWeakLinkage()) continue;
-      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
+      OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
     }
 
     for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
       if (!I->hasExternalWeakLinkage()) continue;
-      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
+      OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
     }
   }
 
@@ -932,10 +948,10 @@ bool AsmPrinter::doFinalization(Module &M) {
     OutStreamer.AddBlankLine();
     for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
          I != E; ++I) {
-      MCSymbol *Name = Mang->getSymbol(I);
+      MCSymbol *Name = getSymbol(I);
 
       const GlobalValue *GV = I->getAliasedGlobal();
-      MCSymbol *Target = Mang->getSymbol(GV);
+      MCSymbol *Target = getSymbol(GV);
 
       if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
         OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
@@ -984,7 +1000,7 @@ bool AsmPrinter::doFinalization(Module &M) {
 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
   this->MF = &MF;
   // Get the function symbol.
-  CurrentFnSym = Mang->getSymbol(MF.getFunction());
+  CurrentFnSym = getSymbol(MF.getFunction());
   CurrentFnSymForSize = CurrentFnSym;
 
   if (isVerbose())
@@ -1291,7 +1307,7 @@ void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
     const GlobalValue *GV =
       dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
     if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
-      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
+      OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
   }
 }
 
@@ -1420,12 +1436,12 @@ void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
                             OutContext);
 
   if (!MAI->hasSetDirective())
-    OutStreamer.EmitValue(Diff, 4);
+    OutStreamer.EmitValue(Diff, Size);
   else {
     // Otherwise, emit with .set (aka assignment).
     MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
     OutStreamer.EmitAssignment(SetLabel, Diff);
-    OutStreamer.EmitSymbolValue(SetLabel, 4);
+    OutStreamer.EmitSymbolValue(SetLabel, Size);
   }
 }
 
@@ -1486,7 +1502,7 @@ static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
     return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
 
   if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
-    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
+    return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
 
   if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
     return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);