Make sure we unique static-local decls across multiple emissions of

the function body, but do so in a way that doesn't make any assumptions
about the static local actually having a proper, unique mangling,
since apparently we don't do that correctly at all.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153776 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 76 insertions, 51 deletions

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 970f0b2389..8c154f0708 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -273,11 +273,23 @@ void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
   llvm::Value *&DMEntry = LocalDeclMap[&D];
   assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
 
-  llvm::GlobalVariable *GV = CreateStaticVarDecl(D, ".", Linkage);
+  // Check to see if we already have a global variable for this
+  // declaration.  This can happen when double-emitting function
+  // bodies, e.g. with complete and base constructors.
+  llvm::Constant *addr =
+    CGM.getStaticLocalDeclAddress(&D);
+
+  llvm::GlobalVariable *var;
+  if (addr) {
+    var = cast<llvm::GlobalVariable>(addr->stripPointerCasts());
+  } else {
+    addr = var = CreateStaticVarDecl(D, ".", Linkage);
+  }
 
   // Store into LocalDeclMap before generating initializer to handle
   // circular references.
-  DMEntry = GV;
+  DMEntry = addr;
+  CGM.setStaticLocalDeclAddress(&D, addr);
 
   // We can't have a VLA here, but we can have a pointer to a VLA,
   // even though that doesn't really make any sense.
@@ -285,42 +297,38 @@ void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
   if (D.getType()->isVariablyModifiedType())
     EmitVariablyModifiedType(D.getType());
 
-  // Local static block variables must be treated as globals as they may be
-  // referenced in their RHS initializer block-literal expresion.
-  CGM.setStaticLocalDeclAddress(&D, GV);
+  // Save the type in case adding the initializer forces a type change.
+  llvm::Type *expectedType = addr->getType();
 
   // If this value has an initializer, emit it.
   if (D.getInit())
-    GV = AddInitializerToStaticVarDecl(D, GV);
+    var = AddInitializerToStaticVarDecl(D, var);
 
-  GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
+  var->setAlignment(getContext().getDeclAlign(&D).getQuantity());
 
   if (D.hasAttr<AnnotateAttr>())
-    CGM.AddGlobalAnnotations(&D, GV);
+    CGM.AddGlobalAnnotations(&D, var);
 
   if (const SectionAttr *SA = D.getAttr<SectionAttr>())
-    GV->setSection(SA->getName());
+    var->setSection(SA->getName());
 
   if (D.hasAttr<UsedAttr>())
-    CGM.AddUsedGlobal(GV);
+    CGM.AddUsedGlobal(var);
 
   // We may have to cast the constant because of the initializer
   // mismatch above.
   //
   // FIXME: It is really dangerous to store this in the map; if anyone
   // RAUW's the GV uses of this constant will be invalid.
-  llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
-  llvm::Type *LPtrTy =
-    LTy->getPointerTo(CGM.getContext().getTargetAddressSpace(D.getType()));
-  llvm::Constant *CastedVal = llvm::ConstantExpr::getBitCast(GV, LPtrTy);
-  DMEntry = CastedVal;
-  CGM.setStaticLocalDeclAddress(&D, CastedVal);
+  llvm::Constant *castedAddr = llvm::ConstantExpr::getBitCast(var, expectedType);
+  DMEntry = castedAddr;
+  CGM.setStaticLocalDeclAddress(&D, castedAddr);
 
   // Emit global variable debug descriptor for static vars.
   CGDebugInfo *DI = getDebugInfo();
   if (DI) {
     DI->setLocation(D.getLocation());
-    DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D);
+    DI->EmitGlobalVariable(var, &D);
   }
 }
 
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 5719afb612..38f5008d89 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -280,6 +280,7 @@ class CodeGenModule : public CodeGenTypeCache {
   llvm::StringMap<llvm::Constant*> CFConstantStringMap;
   llvm::StringMap<llvm::GlobalVariable*> ConstantStringMap;
   llvm::DenseMap<const Decl*, llvm::Constant *> StaticLocalDeclMap;
+  llvm::DenseMap<const Decl*, llvm::GlobalVariable*> StaticLocalDeclGuardMap;
   
   llvm::DenseMap<QualType, llvm::Constant *> AtomicSetterHelperFnMap;
   llvm::DenseMap<QualType, llvm::Constant *> AtomicGetterHelperFnMap;
@@ -405,6 +406,14 @@ public:
     StaticLocalDeclMap[D] = C;
   }
 
+  llvm::GlobalVariable *getStaticLocalDeclGuardAddress(const VarDecl *D) {
+    return StaticLocalDeclGuardMap[D];
+  }
+  void setStaticLocalDeclGuardAddress(const VarDecl *D, 
+                                      llvm::GlobalVariable *C) {
+    StaticLocalDeclGuardMap[D] = C;
+  }
+
   llvm::Constant *getAtomicSetterHelperFnMap(QualType Ty) {
     return AtomicSetterHelperFnMap[Ty];
   }
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index 6fcf83d5ac..98f67f34df 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -1064,8 +1064,8 @@ namespace {
 /// just special-case it at particular places.
 void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
                                     const VarDecl &D,
-                                    llvm::GlobalVariable *GV,
-                                    bool PerformInit) {
+                                    llvm::GlobalVariable *var,
+                                    bool shouldPerformInit) {
   CGBuilderTy &Builder = CGF.Builder;
 
   // We only need to use thread-safe statics for local variables;
@@ -1073,35 +1073,44 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
   bool threadsafe =
     (getContext().getLangOpts().ThreadsafeStatics && D.isLocalVarDecl());
 
-  llvm::IntegerType *GuardTy;
-
   // If we have a global variable with internal linkage and thread-safe statics
   // are disabled, we can just let the guard variable be of type i8.
-  bool useInt8GuardVariable = !threadsafe && GV->hasInternalLinkage();
+  bool useInt8GuardVariable = !threadsafe && var->hasInternalLinkage();
+
+  llvm::IntegerType *guardTy;
   if (useInt8GuardVariable) {
-    GuardTy = CGF.Int8Ty;
+    guardTy = CGF.Int8Ty;
   } else {
     // Guard variables are 64 bits in the generic ABI and 32 bits on ARM.
-    GuardTy = (IsARM ? CGF.Int32Ty : CGF.Int64Ty);
+    guardTy = (IsARM ? CGF.Int32Ty : CGF.Int64Ty);
+  }
+  llvm::PointerType *guardPtrTy = guardTy->getPointerTo();
+
+  // Create the guard variable if we don't already have it (as we
+  // might if we're double-emitting this function body).
+  llvm::GlobalVariable *guard = CGM.getStaticLocalDeclGuardAddress(&D);
+  if (!guard) {
+    // Mangle the name for the guard.
+    SmallString<256> guardName;
+    {
+      llvm::raw_svector_ostream out(guardName);
+      getMangleContext().mangleItaniumGuardVariable(&D, out);
+      out.flush();
+    }
+
+    // Create the guard variable with a zero-initializer.
+    // Just absorb linkage and visibility from the guarded variable.
+    guard = new llvm::GlobalVariable(CGM.getModule(), guardTy,
+                                     false, var->getLinkage(),
+                                     llvm::ConstantInt::get(guardTy, 0),
+                                     guardName.str());
+    guard->setVisibility(var->getVisibility());
+
+    CGM.setStaticLocalDeclGuardAddress(&D, guard);
   }
-  llvm::PointerType *GuardPtrTy = GuardTy->getPointerTo();
-
-  // Create the guard variable.
-  SmallString<256> GuardVName;
-  llvm::raw_svector_ostream Out(GuardVName);
-  getMangleContext().mangleItaniumGuardVariable(&D, Out);
-  Out.flush();
-
-  // Just absorb linkage and visibility from the variable.
-  llvm::GlobalVariable *GuardVariable =
-    new llvm::GlobalVariable(CGM.getModule(), GuardTy,
-                             false, GV->getLinkage(),
-                             llvm::ConstantInt::get(GuardTy, 0),
-                             GuardVName.str());
-  GuardVariable->setVisibility(GV->getVisibility());
 
   // Test whether the variable has completed initialization.
-  llvm::Value *IsInitialized;
+  llvm::Value *isInitialized;
 
   // ARM C++ ABI 3.2.3.1:
   //   To support the potential use of initialization guard variables
@@ -1115,9 +1124,9 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
   //         ...
   //     }
   if (IsARM && !useInt8GuardVariable) {
-    llvm::Value *V = Builder.CreateLoad(GuardVariable);
+    llvm::Value *V = Builder.CreateLoad(guard);
     V = Builder.CreateAnd(V, Builder.getInt32(1));
-    IsInitialized = Builder.CreateIsNull(V, "guard.uninitialized");
+    isInitialized = Builder.CreateIsNull(V, "guard.uninitialized");
 
   // Itanium C++ ABI 3.3.2:
   //   The following is pseudo-code showing how these functions can be used:
@@ -1135,9 +1144,8 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
   //     }
   } else {
     // Load the first byte of the guard variable.
-    llvm::Type *PtrTy = Builder.getInt8PtrTy();
     llvm::LoadInst *LI = 
-      Builder.CreateLoad(Builder.CreateBitCast(GuardVariable, PtrTy));
+      Builder.CreateLoad(Builder.CreateBitCast(guard, CGM.Int8PtrTy));
     LI->setAlignment(1);
 
     // Itanium ABI:
@@ -1149,14 +1157,14 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
     if (threadsafe)
       LI->setAtomic(llvm::Acquire);
 
-    IsInitialized = Builder.CreateIsNull(LI, "guard.uninitialized");
+    isInitialized = Builder.CreateIsNull(LI, "guard.uninitialized");
   }
 
   llvm::BasicBlock *InitCheckBlock = CGF.createBasicBlock("init.check");
   llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
 
   // Check if the first byte of the guard variable is zero.
-  Builder.CreateCondBr(IsInitialized, InitCheckBlock, EndBlock);
+  Builder.CreateCondBr(isInitialized, InitCheckBlock, EndBlock);
 
   CGF.EmitBlock(InitCheckBlock);
 
@@ -1164,7 +1172,7 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
   if (threadsafe) {    
     // Call __cxa_guard_acquire.
     llvm::Value *V
-      = Builder.CreateCall(getGuardAcquireFn(CGM, GuardPtrTy), GuardVariable);
+      = Builder.CreateCall(getGuardAcquireFn(CGM, guardPtrTy), guard);
                
     llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
   
@@ -1172,22 +1180,22 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
                          InitBlock, EndBlock);
   
     // Call __cxa_guard_abort along the exceptional edge.
-    CGF.EHStack.pushCleanup<CallGuardAbort>(EHCleanup, GuardVariable);
+    CGF.EHStack.pushCleanup<CallGuardAbort>(EHCleanup, guard);
     
     CGF.EmitBlock(InitBlock);
   }
 
   // Emit the initializer and add a global destructor if appropriate.
-  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
+  CGF.EmitCXXGlobalVarDeclInit(D, var, shouldPerformInit);
 
   if (threadsafe) {
     // Pop the guard-abort cleanup if we pushed one.
     CGF.PopCleanupBlock();
 
     // Call __cxa_guard_release.  This cannot throw.
-    Builder.CreateCall(getGuardReleaseFn(CGM, GuardPtrTy), GuardVariable);
+    Builder.CreateCall(getGuardReleaseFn(CGM, guardPtrTy), guard);
   } else {
-    Builder.CreateStore(llvm::ConstantInt::get(GuardTy, 1), GuardVariable);
+    Builder.CreateStore(llvm::ConstantInt::get(guardTy, 1), guard);
   }
 
   CGF.EmitBlock(EndBlock);