Prevent clang from emitting output when input has errors

+ test case
<rdar://problem/6080040>
http://llvm.org/bugs/show_bug.cgi?id=2280

llvm-svn: 53756

clang/Driver/clang.cpp

@@ -1285,6 +1285,12 @@ static void ProcessInputFile(Preprocessor &PP, PreprocessorFactory &PPF,
     ParseAST(PP, Consumer, Stats);
   }
 
+  // Don't emit code when the input had errors.
+  if (CodeGenModule && PP.getDiagnostics().hasErrorOccurred()) {
+    delete CodeGenModule;
+    CodeGenModule = 0;
+  }
+
   // If running the code generator, finish up now.
   if (CodeGenModule) {
     std::ostream *Out;

clang/test/CodeGen/2008-07-17-no-emit-on-error.c

@@ -0,0 +1,10 @@
+// RUN: rm -f %t1.bc 
+// RUN: ! clang %s -emit-llvm-bc -o %t1.bc
+// RUN: ! test -f %t1.bc
+
+void f() {
+}
+
+void g() {
+  *10;
+}