Add more Parser/Sema support for GCC asm-label extension.

 - ActOnDeclarator now takes an additional parameter which is the
   AsmLabel if used. Its unfortunate that this bubbles up this high,
   but we cannot just lump it in as an attribute without mistakenly
   *accepting* it as an attribute.
 - The actual asm-label itself is, however, encoded as an AsmLabelAttr
   on the FunctionDecl.
 - Slightly improved parser error recovery on malformed asm-labels.
 - CodeGen support still missing...


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54339 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 59 insertions, 18 deletions

diff --git a/Driver/PrintParserCallbacks.cpp b/Driver/PrintParserCallbacks.cpp
index fec13e3909..2de16144d5 100644
--- a/Driver/PrintParserCallbacks.cpp
+++ b/Driver/PrintParserCallbacks.cpp
@@ -30,7 +30,7 @@ namespace {
     /// and 'Init' specifies the initializer if any.  This is for things like:
     /// "int X = 4" or "typedef int foo".
     virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D,
-                                    DeclTy *LastInGroup) {
+                                    DeclTy *LastInGroup, ExprTy *AsmLabel) {
       llvm::cout << __FUNCTION__ << " ";
       if (IdentifierInfo *II = D.getIdentifier()) {
         llvm::cout << "'" << II->getName() << "'";
@@ -40,7 +40,7 @@ namespace {
       llvm::cout << "\n";
       
       // Pass up to EmptyActions so that the symbol table is maintained right.
-      return MinimalAction::ActOnDeclarator(S, D, LastInGroup);
+      return MinimalAction::ActOnDeclarator(S, D, LastInGroup, AsmLabel);
     }
     /// ActOnPopScope - This callback is called immediately before the specified
     /// scope is popped and deleted.
diff --git a/include/clang/AST/Attr.h b/include/clang/AST/Attr.h
index ea052559be..71f981bd50 100644
--- a/include/clang/AST/Attr.h
+++ b/include/clang/AST/Attr.h
@@ -28,6 +28,7 @@ public:
     Alias,
     Aligned,
     Annotate,
+    AsmLabel, // Represent GCC asm label extension.
     Constructor,
     Deprecated,
     Destructor,
@@ -115,6 +116,20 @@ public:
   static bool classof(const AnnotateAttr *A) { return true; }
 };
 
+class AsmLabelAttr : public Attr {
+  std::string Label;
+public:
+  AsmLabelAttr(const std::string &L) : Attr(AsmLabel), Label(L) {}
+  
+  const std::string& getLabel() const { return Label; }
+  
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Attr *A) {
+    return A->getKind() == AsmLabel;
+  }
+  static bool classof(const AsmLabelAttr *A) { return true; }
+};
+
 class AliasAttr : public Attr {
   std::string Aliasee;
 public:
diff --git a/include/clang/Parse/Action.h b/include/clang/Parse/Action.h
index 2b6f713441..4f7937a36c 100644
--- a/include/clang/Parse/Action.h
+++ b/include/clang/Parse/Action.h
@@ -105,7 +105,12 @@ public:
   /// LastInGroup is non-null for cases where one declspec has multiple
   /// declarators on it.  For example in 'int A, B', ActOnDeclarator will be
   /// called with LastInGroup=A when invoked for B.
-  virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D,DeclTy *LastInGroup) {
+  ///
+  /// AsmLabel is non-null only for top-level function declarations
+  /// which use the GCC asm-label extension (the expression must be a
+  /// constant string).
+  virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup,
+                                  ExprTy *AsmLabel) {
     return 0;
   }
 
@@ -139,7 +144,7 @@ public:
   virtual DeclTy *ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
     // Default to ActOnDeclarator.
     return ActOnStartOfFunctionDef(FnBodyScope,
-                                   ActOnDeclarator(FnBodyScope, D, 0));
+                                   ActOnDeclarator(FnBodyScope, D, 0, 0));
   }
 
   /// ActOnStartOfFunctionDef - This is called at the start of a function
@@ -834,7 +839,8 @@ public:
   /// ActOnDeclarator - If this is a typedef declarator, we modify the
   /// IdentifierInfo::FETokenInfo field to keep track of this fact, until S is
   /// popped.
-  virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup);
+  virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup,
+                                  ExprTy *AsmLabel);
   
   /// ActOnPopScope - When a scope is popped, if any typedefs are now 
   /// out-of-scope, they are removed from the IdentifierInfo::FETokenInfo field.
diff --git a/lib/Parse/MinimalAction.cpp b/lib/Parse/MinimalAction.cpp
index cb130c3d26..352925535d 100644
--- a/lib/Parse/MinimalAction.cpp
+++ b/lib/Parse/MinimalAction.cpp
@@ -63,7 +63,8 @@ MinimalAction::isTypeName(const IdentifierInfo &II, Scope *S) {
 /// IdentifierInfo::FETokenInfo field to keep track of this fact, until S is
 /// popped.
 Action::DeclTy *
-MinimalAction::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup) {
+MinimalAction::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup,
+                               ExprTy *AsmLabel) {
   IdentifierInfo *II = D.getIdentifier();
   
   // If there is no identifier associated with this declarator, bail out.
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 81cb0ce627..33482c5700 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -256,8 +256,14 @@ ParseInitDeclaratorListAfterFirstDeclarator(Declarator &D) {
   // rest of the init-declarator-list.
   while (1) {
     // If a simple-asm-expr is present, parse it.
-    if (Tok.is(tok::kw_asm))
-      ParseSimpleAsm();
+    ExprResult AsmLabel;
+    if (Tok.is(tok::kw_asm)) {
+      AsmLabel = ParseSimpleAsm();
+      if (AsmLabel.isInvalid) {
+        SkipUntil(tok::semi);
+        return 0;
+      }
+    }
     
     // If attributes are present, parse them.
     if (Tok.is(tok::kw___attribute))
@@ -265,13 +271,13 @@ ParseInitDeclaratorListAfterFirstDeclarator(Declarator &D) {
 
     // Inform the current actions module that we just parsed this declarator.
     // FIXME: pass asm & attributes.
-    LastDeclInGroup = Actions.ActOnDeclarator(CurScope, D, LastDeclInGroup);
+    LastDeclInGroup = Actions.ActOnDeclarator(CurScope, D, LastDeclInGroup,
+                                              AsmLabel.Val);
         
     // Parse declarator '=' initializer.
-    ExprResult Init;
     if (Tok.is(tok::equal)) {
       ConsumeToken();
-      Init = ParseInitializer();
+      ExprResult Init = ParseInitializer();
       if (Init.isInvalid) {
         SkipUntil(tok::semi);
         return 0;
diff --git a/lib/Parse/ParseObjc.cpp b/lib/Parse/ParseObjc.cpp
index 980105a02c..467cbd84a0 100644
--- a/lib/Parse/ParseObjc.cpp
+++ b/lib/Parse/ParseObjc.cpp
@@ -1222,7 +1222,7 @@ Parser::StmtResult Parser::ParseObjCTryStmt(SourceLocation atLoc) {
           ParseDeclarator(DeclaratorInfo);
           if (DeclaratorInfo.getIdentifier()) {
             DeclTy *aBlockVarDecl = Actions.ActOnDeclarator(CurScope, 
-                                                          DeclaratorInfo, 0);
+                                                            DeclaratorInfo, 0, 0);
             StmtResult stmtResult =
               Actions.ActOnDeclStmt(aBlockVarDecl, 
                                     DS.getSourceRange().getBegin(),
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index ef07d3f08b..9eab4fda15 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -670,7 +670,11 @@ Parser::ExprResult Parser::ParseSimpleAsm() {
 
   ExprResult Result = ParseAsmStringLiteral();
 
-  MatchRHSPunctuation(tok::r_paren, Loc);
+  if (Result.isInvalid) {
+    SkipUntil(tok::r_paren);
+  } else {
+    MatchRHSPunctuation(tok::r_paren, Loc);
+  }
 
   return Result;
 }
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 0fda782fcb..864b464d5f 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -211,7 +211,8 @@ private:
   // Symbol table / Decl tracking callbacks: SemaDecl.cpp.
   //
   virtual TypeTy *isTypeName(const IdentifierInfo &II, Scope *S);
-  virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup);
+  virtual DeclTy *ActOnDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup,
+                                  ExprTy *AsmLabel);
   virtual DeclTy *ActOnParamDeclarator(Scope *S, Declarator &D);
   virtual void ActOnParamDefaultArgument(DeclTy *param, 
                                          SourceLocation EqualLoc,
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index e9343e3989..64e62369e7 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -609,7 +609,7 @@ bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) {
 }
 
 Sema::DeclTy *
-Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) {
+Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl, ExprTy *AsmLabel) {
   ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl);
   IdentifierInfo *II = D.getIdentifier();
   
@@ -700,6 +700,14 @@ Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) {
     // Handle attributes.
     ProcessDeclAttributes(NewFD, D);
 
+    // Handle GNU asm-label extension (encoded as an attribute).
+    if (Expr *E = (Expr*) AsmLabel) {
+      // The parser guarantees this is a string.
+      StringLiteral *SE = cast<StringLiteral>(E);  
+      NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(),
+                                                  SE->getByteLength())));
+    }
+
     // Copy the parameter declarations from the declarator D to
     // the function declaration NewFD, if they are available.
     if (D.getNumTypeObjects() > 0 &&
@@ -1569,7 +1577,7 @@ Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
   }
 
   return ActOnStartOfFunctionDef(FnBodyScope,
-                                 ActOnDeclarator(GlobalScope, D, 0));
+                                 ActOnDeclarator(GlobalScope, D, 0, 0));
 }
 
 Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) {
@@ -1661,7 +1669,7 @@ ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
   CurContext = Context.getTranslationUnitDecl();
  
   FunctionDecl *FD = 
-    dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0)));
+    dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0, 0)));
   FD->setImplicit();
 
   CurContext = PrevDC;
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 9dc62dcc4a..d5603166d8 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -371,7 +371,7 @@ Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
   if (isInstField)
     Member = static_cast<Decl*>(ActOnField(S, Loc, D, BitWidth));
   else
-    Member = static_cast<Decl*>(ActOnDeclarator(S, D, LastInGroup));
+    Member = static_cast<Decl*>(ActOnDeclarator(S, D, LastInGroup, 0));
 
   if (!Member) return LastInGroup;