[UpdateTestChecks] Update tests option

Summary:
Port of new feature introduced https://reviews.llvm.org/D65610 to other update scripts.

- update_*_checks.py: add an alias -u for --update-only
- port --update-only to other update_*_test_checks.py scripts
- update script aborts if the test file was generated by another update_*_test_checks.py utility

Reviewers: lebedev.ri, RKSimon, MaskRay, reames, gbedwell

Reviewed By: MaskRay

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65793

llvm-svn: 368174
diff --git a/llvm/utils/update_llc_test_checks.py b/llvm/utils/update_llc_test_checks.py
index 9f74a2e..1f7d939 100755
--- a/llvm/utils/update_llc_test_checks.py
+++ b/llvm/utils/update_llc_test_checks.py
@@ -38,10 +38,13 @@
       help='Use more regex for x86 matching to reduce diffs between various subtargets')
   parser.add_argument(
       '--no_x86_scrub_rip', action='store_false', dest='x86_scrub_rip')
+  parser.add_argument('-u', '--update-only', action='store_true',
+                      help='Only update test if it was already autogened')
   parser.add_argument('tests', nargs='+')
   args = parser.parse_args()
 
-  autogenerated_note = (ADVERT + 'utils/' + os.path.basename(__file__))
+  script_name = os.path.basename(__file__)
+  autogenerated_note = (ADVERT + 'utils/' + script_name)
 
   test_paths = [test for pattern in args.tests for test in glob.glob(pattern)]
   for test in test_paths:
@@ -49,6 +52,16 @@
       print('Scanning for RUN lines in test file: %s' % (test,), file=sys.stderr)
     with open(test) as f:
       input_lines = [l.rstrip() for l in f]
+    
+    first_line = input_lines[0] if input_lines else ""
+    if 'autogenerated' in first_line and script_name not in first_line:
+      common.warn("Skipping test which wasn't autogenerated by " + script_name, test)
+      continue
+
+    if args.update_only:
+      if not first_line or 'autogenerated' not in first_line:
+        common.warn("Skipping test which isn't autogenerated: " + test)
+        continue
 
     triple_in_ir = None
     for l in input_lines:
@@ -73,6 +86,10 @@
 
     run_list = []
     for l in run_lines:
+      if '|' not in l:
+        common.warn('Skipping unparseable RUN line: ' + l)
+        continue
+
       commands = [cmd.strip() for cmd in l.split('|', 1)]
       llc_cmd = commands[0]
 
@@ -91,11 +108,11 @@
         filecheck_cmd = commands[1]
       common.verify_filecheck_prefixes(filecheck_cmd)
       if not llc_cmd.startswith('llc '):
-        print('WARNING: Skipping non-llc RUN line: ' + l, file=sys.stderr)
+        common.warn('Skipping non-llc RUN line: ' + l)
         continue
 
       if not filecheck_cmd.startswith('FileCheck '):
-        print('WARNING: Skipping non-FileChecked RUN line: ' + l, file=sys.stderr)
+        common.warn('Skipping non-FileChecked RUN line: ' + l)
         continue
 
       llc_cmd_args = llc_cmd[len('llc'):].strip()