[Driver] -###: exit with code 1 if hasErrorOccurred

The exit code for -### is inconsistent. Unrecognized options lead to
exit code 1, as expected. However, most others errors (including invalid
option value) lead to exit code 0, differing from GCC and most utilities.

This is a longstanding quirk of -###, and we didn't fix it because many
driver tests need adjustment.

Change -### to be similar to -fdriver-only -v and exit with code 1.

This requires fixing many driver tests, but the end result gives us
stronger tests.

* Existing `RUN: %clang -### ...` tests usually don't use `CHECK-NOT: error:` or `--implicit-check-not=error:`.
  If a change introduces an error, such a change usually cannot be detected.
* Many folks contributing new tests don't know `-fdriver-only -v`.
  To test no driver error/warning for new tests, they can use the familiar `-### -Werror`
  instead of `-fdriver-only -v -Werror`.

An incomplete list of prerequisite test improvement:

* 2f79bb10461d114783a1548201928549ace09755: add -nogpulib to some AMDGPU tests
* 9155e517e6e1cda474d0d0fa82f71696c325bc10: add --cuda-path= (test w/ and w/o /usr/local/cuda)
* 80765ede5bbcca1364c2d4ae06127011eaba6389: -mcpu=native may return either 0 or 1, depending on whether `--target=` specifies a native target
* abae53f43f0d1da8d8e421f4a628d7ec64d6e365: fix -fuse-ld=lld misuses (test w/o and w/o /usr/local/bin/ld.lld)
* ab68df505e5bb8808ee44f53044b50ca7575098e: add -resource-dir= and -fvisibility=hidden
 to some -fsanitize=cfi tests
* d5ca1602f64114f612ad5630f04e4aa90591c78d: --rtlib=platform without --unwindlib= may fail if CLANG_DEFAULT_UNWINDLIB=unwindlib

Reviewed By: jhuber6, yaxunl, dblaikie

Differential Revision: https://reviews.llvm.org/D156363

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 4883501..a43d3f0 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -1889,7 +1889,7 @@ int Driver::ExecuteCompilation(
   // Just print if -### was present.
   if (C.getArgs().hasArg(options::OPT__HASH_HASH_HASH)) {
     C.getJobs().Print(llvm::errs(), "\n", true);
-    return 0;
+    return Diags.hasErrorOccurred() ? 1 : 0;
   }
 
   // If there were errors building the compilation, quit now.