Improve name mangling for blocks and support mangling of static local

variables within blocks. We loosely follow GCC's mangling, but since
these are always internal symbols the names don't really matter. I
intend to revisit block mangling later, because GCC's mangling is
rather verbose. <rdar://problem/8015719>.

llvm-svn: 104610

6 files changed, 67 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp
index f49b6ee18b8..dcae95f3de1 100644
--- a/clang/lib/CodeGen/CGBlocks.cpp
+++ b/clang/lib/CodeGen/CGBlocks.cpp
@@ -791,9 +791,10 @@ CodeGenFunction::GenerateBlockFunction(const BlockExpr *BExpr,
   CodeGenTypes &Types = CGM.getTypes();
   const llvm::FunctionType *LTy = Types.GetFunctionType(FI, IsVariadic);
 
+  MangleBuffer Name;
+  CGM.getMangledName(Name, BD);
   llvm::Function *Fn =
-    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
-                           llvm::Twine("__") + Info.Name + "_block_invoke_",
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, Name,
                            &CGM.getModule());
 
   CGM.SetInternalFunctionAttributes(BD, Fn, FI);
diff --git a/clang/lib/CodeGen/CGCXX.cpp b/clang/lib/CodeGen/CGCXX.cpp
index 85222fe9dba..be4256a691d 100644
--- a/clang/lib/CodeGen/CGCXX.cpp
+++ b/clang/lib/CodeGen/CGCXX.cpp
@@ -230,6 +230,10 @@ CodeGenModule::GetAddrOfCXXConstructor(const CXXConstructorDecl *D,
                       GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type)));
 }
 
+void CodeGenModule::getMangledName(MangleBuffer &Buffer, const BlockDecl *BD) {
+  getMangleContext().mangleBlock(BD, Buffer.getBuffer());
+}
+
 void CodeGenModule::getMangledCXXCtorName(MangleBuffer &Name,
                                           const CXXConstructorDecl *D,
                                           CXXCtorType Type) {
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 222dcc4b8f5..73de0fd7738 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -37,6 +37,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm)
   LLVMPointerWidth = Target.getPointerWidth(0);
   Exceptions = getContext().getLangOptions().Exceptions;
   CatchUndefined = getContext().getLangOptions().CatchUndefined;
+  CGM.getMangleContext().startNewFunction();
 }
 
 ASTContext &CodeGenFunction::getContext() const {
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index e225462fac8..b14c35f3845 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -413,6 +413,7 @@ public:
 
   void getMangledName(MangleBuffer &Buffer, GlobalDecl D);
   void getMangledName(MangleBuffer &Buffer, const NamedDecl *ND);
+  void getMangledName(MangleBuffer &Buffer, const BlockDecl *BD);
   void getMangledCXXCtorName(MangleBuffer &Buffer,
                              const CXXConstructorDecl *D,
                              CXXCtorType Type);
diff --git a/clang/lib/CodeGen/Mangle.cpp b/clang/lib/CodeGen/Mangle.cpp
index 46a9f6ce82b..88e4c647c87 100644
--- a/clang/lib/CodeGen/Mangle.cpp
+++ b/clang/lib/CodeGen/Mangle.cpp
@@ -102,6 +102,7 @@ public:
   llvm::raw_svector_ostream &getStream() { return Out; }
 
   void mangle(const NamedDecl *D, llvm::StringRef Prefix = "_Z");
+  void mangleBlock(const BlockDecl *BD);
   void mangleCallOffset(int64_t NonVirtual, int64_t Virtual);
   void mangleNumber(int64_t Number);
   void mangleFunctionEncoding(const FunctionDecl *FD);
@@ -469,6 +470,31 @@ void CXXNameMangler::mangleNumber(int64_t Number) {
   Out << Number;
 }
 
+void CXXNameMangler::mangleBlock(const BlockDecl *BD) {
+  // Mangle the context of the block.
+  // FIXME: We currently mimic GCC's mangling scheme, which leaves much to be
+  // desired. Come up with a better mangling scheme.
+  const DeclContext *DC = BD->getDeclContext();
+  while (isa<BlockDecl>(DC) || isa<EnumDecl>(DC))
+    DC = DC->getParent();
+  if (DC->isFunctionOrMethod()) {
+    Out << "__";
+    if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC))
+      mangleObjCMethodName(Method);
+    else {
+      const NamedDecl *ND = cast<NamedDecl>(DC);
+      if (IdentifierInfo *II = ND->getIdentifier())
+        Out << II->getName();
+      else {
+        mangleUnqualifiedName(ND);
+      }
+    }
+    Out << "_block_invoke_" << Context.getBlockId(BD, true);
+  } else {
+    Out << "__block_global_" << Context.getBlockId(BD, false);
+  }
+}
+
 void CXXNameMangler::mangleCallOffset(int64_t NonVirtual, int64_t Virtual) {
   //  <call-offset>  ::= h <nv-offset> _
   //                 ::= v <v-offset> _
@@ -752,6 +778,14 @@ void CXXNameMangler::manglePrefix(const DeclContext *DC, bool NoFunction) {
   if (DC->isTranslationUnit())
     return;
 
+  if (const BlockDecl *Block = dyn_cast<BlockDecl>(DC)) {
+    manglePrefix(DC->getParent(), NoFunction);    
+    llvm::SmallString<64> Name;
+    Context.mangleBlock(Block, Name);
+    Out << Name.size() << Name;
+    return;
+  }
+  
   if (mangleSubstitution(cast<NamedDecl>(DC)))
     return;
 
@@ -762,8 +796,10 @@ void CXXNameMangler::manglePrefix(const DeclContext *DC, bool NoFunction) {
     TemplateParameterList *TemplateParameters = TD->getTemplateParameters();
     mangleTemplateArgs(*TemplateParameters, *TemplateArgs);
   }
-  else if(NoFunction && isa<FunctionDecl>(DC))
+  else if(NoFunction && (isa<FunctionDecl>(DC) || isa<ObjCMethodDecl>(DC)))
     return;
+  else if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC))
+    mangleObjCMethodName(Method);
   else {
     manglePrefix(DC->getParent(), NoFunction);
     mangleUnqualifiedName(cast<NamedDecl>(DC));
@@ -2033,6 +2069,12 @@ void MangleContext::mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type,
   Mangler.mangle(D);
 }
 
+void MangleContext::mangleBlock(const BlockDecl *BD,
+                                llvm::SmallVectorImpl<char> &Res) {
+  CXXNameMangler Mangler(*this, Res);
+  Mangler.mangleBlock(BD);
+}
+
 void MangleContext::mangleThunk(const CXXMethodDecl *MD,
                                 const ThunkInfo &Thunk,
                                 llvm::SmallVectorImpl<char> &Res) {
diff --git a/clang/lib/CodeGen/Mangle.h b/clang/lib/CodeGen/Mangle.h
index da3626fc5d3..04f5dd6b21e 100644
--- a/clang/lib/CodeGen/Mangle.h
+++ b/clang/lib/CodeGen/Mangle.h
@@ -26,6 +26,7 @@
 
 namespace clang {
   class ASTContext;
+  class BlockDecl;
   class CXXConstructorDecl;
   class CXXDestructorDecl;
   class CXXMethodDecl;
@@ -73,6 +74,8 @@ class MangleContext {
   llvm::DenseMap<const TagDecl *, uint64_t> AnonStructIds;
   unsigned Discriminator;
   llvm::DenseMap<const NamedDecl*, unsigned> Uniquifier;
+  llvm::DenseMap<const BlockDecl*, unsigned> GlobalBlockIds;
+  llvm::DenseMap<const BlockDecl*, unsigned> LocalBlockIds;
   
 public:
   explicit MangleContext(ASTContext &Context,
@@ -83,6 +86,8 @@ public:
 
   Diagnostic &getDiags() const { return Diags; }
 
+  void startNewFunction() { LocalBlockIds.clear(); }
+  
   uint64_t getAnonymousStructId(const TagDecl *TD) {
     std::pair<llvm::DenseMap<const TagDecl *,
       uint64_t>::iterator, bool> Result =
@@ -90,11 +95,18 @@ public:
     return Result.first->second;
   }
 
+  unsigned getBlockId(const BlockDecl *BD, bool Local) {
+    llvm::DenseMap<const BlockDecl *, unsigned> &BlockIds
+      = Local? LocalBlockIds : GlobalBlockIds;
+    std::pair<llvm::DenseMap<const BlockDecl *, unsigned>::iterator, bool>
+      Result = BlockIds.insert(std::make_pair(BD, BlockIds.size()));
+    return Result.first->second;
+  }
+  
   /// @name Mangler Entry Points
   /// @{
 
   bool shouldMangleDeclName(const NamedDecl *D);
-
   void mangleName(const NamedDecl *D, llvm::SmallVectorImpl<char> &);
   void mangleThunk(const CXXMethodDecl *MD,
                    const ThunkInfo &Thunk,
@@ -114,7 +126,8 @@ public:
                      llvm::SmallVectorImpl<char> &);
   void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type,
                      llvm::SmallVectorImpl<char> &);
-  
+  void mangleBlock(const BlockDecl *BD, llvm::SmallVectorImpl<char> &);
+
   void mangleInitDiscriminator() {
     Discriminator = 0;
   }