Step #1/N of implementing support for __label__: split labels into

LabelDecl and LabelStmt.  There is a 1-1 correspondence between the
two, but this simplifies a bunch of code by itself.  This is because
labels are the only place where we previously had references to random
other statements, causing grief for AST serialization and other stuff.

This does cause one regression (attr(unused) doesn't silence unused
label warnings) which I'll address next.

This does fix some minor bugs:
1. "The only valid attribute " diagnostic was capitalized.
2. Various diagnostics printed as ''labelname'' instead of 'labelname'
3. This reduces duplication of label checking between functions and blocks.

Review appreciated, particularly for the cindex and template bits.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125733 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 17 insertions, 16 deletions

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 129416fa07..97dbf0ba31 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -70,7 +70,7 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
   case Decl::Friend:
   case Decl::FriendTemplate:
   case Decl::Block:
-    
+  case Decl::Label:
     assert(0 && "Declaration not should not be in declstmts!");
   case Decl::Function:  // void X();
   case Decl::Record:    // struct/union/class X;
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index f782c8004a..f809c009ce 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -208,7 +208,7 @@ RValue CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast,
     // emitting them before we evaluate the subexpr.
     const Stmt *LastStmt = S.body_back();
     while (const LabelStmt *LS = dyn_cast<LabelStmt>(LastStmt)) {
-      EmitLabel(*LS);
+      EmitLabel(LS->getDecl());
       LastStmt = LS->getSubStmt();
     }
 
@@ -276,24 +276,24 @@ void CodeGenFunction::EmitBranch(llvm::BasicBlock *Target) {
 }
 
 CodeGenFunction::JumpDest
-CodeGenFunction::getJumpDestForLabel(const LabelStmt *S) {
-  JumpDest &Dest = LabelMap[S];
+CodeGenFunction::getJumpDestForLabel(const LabelDecl *D) {
+  JumpDest &Dest = LabelMap[D];
   if (Dest.isValid()) return Dest;
 
   // Create, but don't insert, the new block.
-  Dest = JumpDest(createBasicBlock(S->getName()),
+  Dest = JumpDest(createBasicBlock(D->getName()),
                   EHScopeStack::stable_iterator::invalid(),
                   NextCleanupDestIndex++);
   return Dest;
 }
 
-void CodeGenFunction::EmitLabel(const LabelStmt &S) {
-  JumpDest &Dest = LabelMap[&S];
+void CodeGenFunction::EmitLabel(const LabelDecl *D) {
+  JumpDest &Dest = LabelMap[D];
 
   // If we didn't need a forward reference to this label, just go
   // ahead and create a destination at the current scope.
   if (!Dest.isValid()) {
-    Dest = getJumpDestInCurrentScope(S.getName());
+    Dest = getJumpDestInCurrentScope(D->getName());
 
   // Otherwise, we need to give this label a target depth and remove
   // it from the branch-fixups list.
@@ -311,7 +311,7 @@ void CodeGenFunction::EmitLabel(const LabelStmt &S) {
 
 
 void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) {
-  EmitLabel(S);
+  EmitLabel(S.getDecl());
   EmitStmt(S.getSubStmt());
 }
 
@@ -327,7 +327,7 @@ void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) {
 
 
 void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) {
-  if (const LabelStmt *Target = S.getConstantTarget()) {
+  if (const LabelDecl *Target = S.getConstantTarget()) {
     EmitBranchThroughCleanup(getJumpDestForLabel(Target));
     return;
   }
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index ee8b98cdd4..b316fa86f1 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -668,7 +668,7 @@ CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
   Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal, Align, false);
 }
 
-llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelStmt *L) {
+llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) {
   // Make sure that there is a block for the indirect goto.
   if (IndirectBranch == 0)
     GetIndirectGotoBlock();
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index c4971506c5..adbc223afc 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -45,6 +45,7 @@ namespace clang {
   class CXXDestructorDecl;
   class CXXTryStmt;
   class Decl;
+  class LabelDecl;
   class EnumConstantDecl;
   class FunctionDecl;
   class FunctionProtoType;
@@ -768,7 +769,7 @@ public:
   /// The given basic block lies in the current EH scope, but may be a
   /// target of a potentially scope-crossing jump; get a stable handle
   /// to which we can perform this jump later.
-  JumpDest getJumpDestInCurrentScope(const char *Name = 0) {
+  JumpDest getJumpDestInCurrentScope(llvm::StringRef Name = llvm::StringRef()) {
     return getJumpDestInCurrentScope(createBasicBlock(Name));
   }
 
@@ -887,7 +888,7 @@ private:
   DeclMapTy LocalDeclMap;
 
   /// LabelMap - This keeps track of the LLVM basic block for each C label.
-  llvm::DenseMap<const LabelStmt*, JumpDest> LabelMap;
+  llvm::DenseMap<const LabelDecl*, JumpDest> LabelMap;
 
   // BreakContinueStack - This keeps track of where break and continue
   // statements should jump to.
@@ -1168,7 +1169,7 @@ public:
 
   /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
   /// label maps to.
-  JumpDest getJumpDestForLabel(const LabelStmt *S);
+  JumpDest getJumpDestForLabel(const LabelDecl *S);
 
   /// SimplifyForwardingBlocks - If the given basic block is only a branch to
   /// another basic block, simplify it. This assumes that no other code could
@@ -1321,7 +1322,7 @@ public:
   /// the input field number being accessed.
   static unsigned getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts);
 
-  llvm::BlockAddress *GetAddrOfLabel(const LabelStmt *L);
+  llvm::BlockAddress *GetAddrOfLabel(const LabelDecl *L);
   llvm::BasicBlock *GetIndirectGotoBlock();
 
   /// EmitNullInitialization - Generate code to set a value of the given type to
@@ -1504,7 +1505,7 @@ public:
 
   /// EmitLabel - Emit the block for the given label. It is legal to call this
   /// function even if there is no current insertion point.
-  void EmitLabel(const LabelStmt &S); // helper for EmitLabelStmt.
+  void EmitLabel(const LabelDecl *D); // helper for EmitLabelStmt.
 
   void EmitLabelStmt(const LabelStmt &S);
   void EmitGotoStmt(const GotoStmt &S);