Implement C++11 semantics for [[noreturn]] attribute. This required splitting

it apart from [[gnu::noreturn]] / __attribute__((noreturn)), since their
semantics are not equivalent (for instance, we treat [[gnu::noreturn]] as
affecting the function type, whereas [[noreturn]] does not).

llvm-svn: 172691

1 files changed, 8 insertions, 1 deletions

diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 7fe49fd995b..d78cc51a77a 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -3032,7 +3032,7 @@ static bool IsBuiltInOrStandardCXX11Attribute(IdentifierInfo *AttrName,
                                  AttributeList::AS_CXX11)) {
   case AttributeList::AT_CarriesDependency:
   case AttributeList::AT_FallThrough:
-  case AttributeList::AT_NoReturn: {
+  case AttributeList::AT_CXX11NoReturn: {
     return true;
   }
 
@@ -3095,6 +3095,8 @@ void Parser::ParseCXX11AttributeSpecifier(ParsedAttributes &attrs,
   ConsumeBracket();
   ConsumeBracket();
 
+  llvm::SmallDenseMap<IdentifierInfo*, SourceLocation, 4> SeenAttrs;
+
   while (Tok.isNot(tok::r_square)) {
     // attribute not present
     if (Tok.is(tok::comma)) {
@@ -3128,6 +3130,11 @@ void Parser::ParseCXX11AttributeSpecifier(ParsedAttributes &attrs,
     bool StandardAttr = IsBuiltInOrStandardCXX11Attribute(AttrName,ScopeName);
     bool AttrParsed = false;
 
+    if (StandardAttr &&
+        !SeenAttrs.insert(std::make_pair(AttrName, AttrLoc)).second)
+      Diag(AttrLoc, diag::err_cxx11_attribute_repeated)
+        << AttrName << SourceRange(SeenAttrs[AttrName]);
+
     // Parse attribute arguments
     if (Tok.is(tok::l_paren)) {
       if (ScopeName && ScopeName->getName() == "gnu") {