[lit] Fail testing if a googletest executable crashes during test discovery

[gparker42]

Summary

googletest formatted tests are discovered by running the test executable. Previously testing would silently succeed if the test executable crashed during the discovery process. Now testing fails with "error: unable to discover google-tests ..." if the test executable exits with a non-zero status.

[• ddunbar]

LGTM.

There might be clients of the capture() API which might aren't expecting it to throw on error, and will need to be updated, but I agree this makes more sense.

[gparker42]

The only other use of capture() in lit itself is capturing sysctl -n hw.ncpu. I didn't look more broadly.

[Eugene.Zelenko]

Committed in rL280455. Please specify "Differential revision: <URL>" in commit message.

utils/lit/lit/formats/googletest.py

def getGTestTests(self, path, litConfig, localConfig):
 
         try:
             lines = lit.util.capture([path, '--gtest_list_tests'],
                                      env=localConfig.environment)
             if kIsWindows:
               lines = lines.replace('\r', '')
             lines = lines.split('\n')
         except:
-            litConfig.error("unable to discover google-tests in %r" % path)
+            litConfig.error("unable to discover google-tests in %r: %s"
+                            % (path, sys.exc_info()[1]))
             raise StopIteration
 
         nested_tests = []
         for ln in lines:
             if not ln.strip():
                 continue
 
             prefix = ''

utils/lit/lit/util.py

def mkdir_p(path):
     except OSError:
         e = sys.exc_info()[1]
         # Ignore EEXIST, which may occur during a race condition.
         if e.errno != errno.EEXIST:
             raise
 
 def capture(args, env=None):
     """capture(command) - Run the given command (or argv list) in a shell and
-    return the standard output."""
+    return the standard output. Raises a CalledProcessError if the command
+    exits with a non-zero status."""
     p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                          env=env)
     out,_ = p.communicate()
+    if p.returncode != 0:
+        raise subprocess.CalledProcessError(cmd=args, returncode=p.returncode)
     return convert_string(out)
 
 def which(command, paths = None):
     """which(command, [paths]) - Look up the given command in the paths string
     (or the PATH environment variable, if unspecified)."""
 
     if paths is None:
         paths = os.environ.get('PATH','')