1 files changed, 24 insertions, 21 deletions
diff --git a/lib/Parse/ParseAST.cpp b/lib/Parse/ParseAST.cpp
index d1c2624..bd4f859 100644
--- a/lib/Parse/ParseAST.cpp
+++ b/lib/Parse/ParseAST.cpp
@@ -12,11 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Parse/ParseAST.h"
+#include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Sema/Sema.h"
 #include "clang/Sema/CodeCompleteConsumer.h"
 #include "clang/Sema/SemaConsumer.h"
 #include "clang/Sema/ExternalSemaSource.h"
 #include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/ExternalASTSource.h"
 #include "clang/AST/Stmt.h"
@@ -77,28 +79,29 @@ void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
   S.getPreprocessor().EnterMainSourceFile();
   P.Initialize();
   S.Initialize();
-  
-  if (ExternalASTSource *External = S.getASTContext().getExternalSource())
-    External->StartTranslationUnit(Consumer);
-  
-  bool Abort = false;
+
+  // C11 6.9p1 says translation units must have at least one top-level
+  // declaration. C++ doesn't have this restriction. We also don't want to
+  // complain if we have a precompiled header, although technically if the PCH
+  // is empty we should still emit the (pedantic) diagnostic.
   Parser::DeclGroupPtrTy ADecl;
-  
-  while (!P.ParseTopLevelDecl(ADecl)) {  // Not end of file.
-    // If we got a null return and something *was* parsed, ignore it.  This
-    // is due to a top-level semicolon, an action override, or a parse error
-    // skipping something.
-    if (ADecl) {
-      if (!Consumer->HandleTopLevelDecl(ADecl.get())) {
-        Abort = true;
-        break;
-      }
-    }
-  };
-
-  if (Abort)
-    return;
-  
+  ExternalASTSource *External = S.getASTContext().getExternalSource();
+  if (External)
+    External->StartTranslationUnit(Consumer);
+
+  if (P.ParseTopLevelDecl(ADecl)) {
+    if (!External && !S.getLangOpts().CPlusPlus)
+      P.Diag(diag::ext_empty_translation_unit);
+  } else {
+    do {
+      // If we got a null return and something *was* parsed, ignore it.  This
+      // is due to a top-level semicolon, an action override, or a parse error
+      // skipping something.
+      if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
+	return;
+    } while (!P.ParseTopLevelDecl(ADecl));
+  }
+
   // Process any TopLevelDecls generated by #pragma weak.
   for (SmallVector<Decl*,2>::iterator
        I = S.WeakTopLevelDecls().begin(),