Indicate success for simple options when clang called with -cc1.

Patch by David Wiberg.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187888 91177308-0d34-0410-b5e6-96231b3b80d8

lib/FrontendTool/ExecuteCompilerInvocation.cpp

@@ -183,7 +183,7 @@ bool clang::ExecuteCompilerInvocation(CompilerInstance *Clang) {
     Opts->PrintHelp(llvm::outs(), "clang -cc1",
                     "LLVM 'Clang' Compiler: http://clang.llvm.org",
                     /*Include=*/ driver::options::CC1Option, /*Exclude=*/ 0);
-    return 0;
+    return true;
   }
 
   // Honor -version.
@@ -191,7 +191,7 @@ bool clang::ExecuteCompilerInvocation(CompilerInstance *Clang) {
   // FIXME: Use a better -version message?
   if (Clang->getFrontendOpts().ShowVersion) {
     llvm::cl::PrintVersionMessage();
-    return 0;
+    return true;
   }
 
   // Load any requested plugins.
@@ -223,7 +223,7 @@ bool clang::ExecuteCompilerInvocation(CompilerInstance *Clang) {
   // This should happen AFTER plugins have been loaded!
   if (Clang->getAnalyzerOpts()->ShowCheckerHelp) {
     ento::printCheckerHelp(llvm::outs(), Clang->getFrontendOpts().Plugins);
-    return 0;
+    return true;
   }
 #endif
 

test/Frontend/cc1-return-codes.c

@@ -0,0 +1,4 @@
+// cc1 immediate arguments (arguments which displays information and exits)
+// shall exit indicating success (return code 0)
+// RUN: %clang -cc1 -help
+// RUN: %clang -cc1 -version