PR18870: Parse language linkage specifiers properly if the string-literal is

spelled in an interesting way.

llvm-svn: 201536

1 files changed, 14 insertions, 23 deletions

diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 5d68453e3fb..b95eb87a6fa 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -279,27 +279,16 @@ Decl *Parser::ParseNamespaceAlias(SourceLocation NamespaceLoc,
 ///         'extern' string-literal declaration
 ///
 Decl *Parser::ParseLinkage(ParsingDeclSpec &DS, unsigned Context) {
-  assert(Tok.is(tok::string_literal) && "Not a string literal!");
-  SmallString<8> LangBuffer;
-  bool Invalid = false;
-  StringRef Lang = PP.getSpelling(Tok, LangBuffer, &Invalid);
-  if (Invalid)
-    return 0;
-
-  // FIXME: This is incorrect: linkage-specifiers are parsed in translation
-  // phase 7, so string-literal concatenation is supposed to occur.
-  //   extern "" "C" "" "+" "+" { } is legal.
-  if (Tok.hasUDSuffix())
-    Diag(Tok, diag::err_invalid_string_udl);
-  SourceLocation Loc = ConsumeStringToken();
+  assert(isTokenStringLiteral() && "Not a string literal!");
+  ExprResult Lang = ParseStringLiteralExpression(false);
 
   ParseScope LinkageScope(this, Scope::DeclScope);
-  Decl *LinkageSpec
-    = Actions.ActOnStartLinkageSpecification(getCurScope(),
-                                             DS.getSourceRange().getBegin(),
-                                             Loc, Lang,
-                                      Tok.is(tok::l_brace) ? Tok.getLocation()
-                                                           : SourceLocation());
+  Decl *LinkageSpec =
+      Lang.isInvalid()
+          ? 0
+          : Actions.ActOnStartLinkageSpecification(
+                getCurScope(), DS.getSourceRange().getBegin(), Lang.take(),
+                Tok.is(tok::l_brace) ? Tok.getLocation() : SourceLocation());
 
   ParsedAttributesWithRange attrs(AttrFactory);
   MaybeParseCXX11Attributes(attrs);
@@ -313,8 +302,9 @@ Decl *Parser::ParseLinkage(ParsingDeclSpec &DS, unsigned Context) {
     // ... but anyway remember that such an "extern" was seen.
     DS.setExternInLinkageSpec(true);
     ParseExternalDeclaration(attrs, &DS);
-    return Actions.ActOnFinishLinkageSpecification(getCurScope(), LinkageSpec,
-                                                   SourceLocation());
+    return LinkageSpec ? Actions.ActOnFinishLinkageSpecification(
+                             getCurScope(), LinkageSpec, SourceLocation())
+                       : 0;
   }
 
   DS.abort();
@@ -331,8 +321,9 @@ Decl *Parser::ParseLinkage(ParsingDeclSpec &DS, unsigned Context) {
   }
 
   T.consumeClose();
-  return Actions.ActOnFinishLinkageSpecification(getCurScope(), LinkageSpec,
-                                                 T.getCloseLocation());
+  return LinkageSpec ? Actions.ActOnFinishLinkageSpecification(
+                           getCurScope(), LinkageSpec, T.getCloseLocation())
+                     : 0;
 }
 
 /// ParseUsingDirectiveOrDeclaration - Parse C++ using using-declaration or