Disable hashes for ANGLE features generator

Features autogen files are small, fast to regenerate.
Run the generator in --verify-only mode and check content every time,
instead of using hashes.

Bug: angleproject:8193
Change-Id: I3988ab50a6c33171b7b7252c03f34a74f09fcf18
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4604579
Commit-Queue: Roman Lavrov <romanl@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>

include/platform/gen_features.py

@@ -140,6 +140,20 @@ def header_path(class_name):
     return 'autogen/' + make_header_name(class_name)
 
 
+def write_or_verify_file(filename, content, verify_only):
+    if verify_only:
+        try:
+            with open(filename) as f:
+                # Note: .gitattributes "* text=auto" handles LF <-> CRLF on Windows
+                return f.read() == content
+        except FileNotFoundError:
+            return False
+    else:
+        with open(filename, 'w') as fout:
+            fout.write(content)
+            return True
+
+
 def main():
     if len(sys.argv) == 2 and sys.argv[1] == 'inputs':
         print(','.join(list(feature_files.keys())))
@@ -149,6 +163,10 @@ def main():
               ',' + feature_list_header_file + ',' + feature_list_source_file)
         return
 
+    # --verify-only enables dirty checks without relying on checked in hashes.
+    # Compares the content of the existing file with the generated content.
+    verify_only = '--verify-only' in sys.argv
+
     name_map = {}
 
     for src_file, (category_prefix, class_name) in feature_files.items():
@@ -191,9 +209,8 @@ def main():
             NAME=class_name.upper(),
             features='\n'.join(features))
 
-        with open(header_path(class_name), 'w') as fout:
-            fout.write(header)
-            fout.close()
+        if not write_or_verify_file(header_path(class_name), header, verify_only):
+            return 1
 
     # Generate helpers for use by tests to override a feature or not.
     feature_enums = []
@@ -206,21 +223,21 @@ def main():
         feature_strings.append(
             template_feature_string.format(VarName=VarName, display_name=display_name))
 
-    with open(feature_list_header_file, 'w') as fout:
-        fout.write(
+    if not write_or_verify_file(
+            feature_list_header_file,
             template_feature_list_header.format(
                 script_name=os.path.basename(__file__),
                 input_file_name='*_features.json',
-                features='\n'.join('    ' + v for v in feature_enums)))
-        fout.close()
+                features='\n'.join('    ' + v for v in feature_enums)), verify_only):
+        return 1
 
-    with open(feature_list_source_file, 'w') as fout:
-        fout.write(
+    if not write_or_verify_file(
+            feature_list_source_file,
             template_feature_list_source.format(
                 script_name=os.path.basename(__file__),
                 input_file_name='*_features.json',
-                features='\n'.join(feature_strings)))
-        fout.close()
+                features='\n'.join(feature_strings)), verify_only):
+        return 1
 
 
 if __name__ == '__main__':

scripts/code_generation_hashes/ANGLE_features.json

@@ -1,28 +0,0 @@
-{
-  "include/platform/autogen/FeaturesD3D_autogen.h":
-    "d0af019005a4e771f23bf59501da6ad8",
-  "include/platform/autogen/FeaturesGL_autogen.h":
-    "ed6342efe54ee4e3fc2b0e4431e4483c",
-  "include/platform/autogen/FeaturesMtl_autogen.h":
-    "d7d21bebe1e95f7b9041769e9db4e975",
-  "include/platform/autogen/FeaturesVk_autogen.h":
-    "765cdbfaac839d8270eb58f61a5a6e93",
-  "include/platform/autogen/FrontendFeatures_autogen.h":
-    "032d7687e0bc9e6ba5bd86029fd71ff2",
-  "include/platform/d3d_features.json":
-    "c3f7694511855304b3f678a6ad461d1e",
-  "include/platform/frontend_features.json":
-    "db98716ec9e23fc17f32bf9bc53cc331",
-  "include/platform/gen_features.py":
-    "7d85e07af44194d80615899accde596f",
-  "include/platform/gl_features.json":
-    "deb7ed855cb00b5cbedf4f3c5bab329a",
-  "include/platform/mtl_features.json":
-    "c1430ea5f79a6da446914b467058d9e7",
-  "include/platform/vk_features.json":
-    "4bf60b8b8430c680ca789cb48257ea3d",
-  "util/autogen/angle_features_autogen.cpp":
-    "58ece285f162dd37588c75bc815c13d5",
-  "util/autogen/angle_features_autogen.h":
-    "251a5ef9e8222dd9ecb3b7ad0d9cb5a5"
-}

scripts/run_code_generation.py

@@ -66,8 +66,6 @@ def auto_script(script):
 
 
 generators = {
-    'ANGLE features':
-        'include/platform/gen_features.py',
     'ANGLE format':
         'src/libANGLE/renderer/gen_angle_format_table.py',
     'ANGLE load functions table':
@@ -135,6 +133,12 @@ generators = {
 }
 
 
+# Fast and supports --verify-only without hashes.
+hashless_generators = {
+    'ANGLE features': 'include/platform/gen_features.py',
+}
+
+
 def md5(fname):
     hash_md5 = hashlib.md5()
     with open(fname, "r") as f:
@@ -252,8 +256,22 @@ def main():
     if not runningSingleGenerator and any_old_hash_missing(all_new_hashes, all_old_hashes):
         any_dirty = True
 
+    # Handle hashless_generators separately as these don't have hash maps.
+    hashless_generators_dirty = False
+    for name, script in sorted(hashless_generators.items()):
+        cmd = [get_executable_name(script), os.path.basename(script)]
+        rc = subprocess.call(cmd + ['--verify-only'], cwd=get_child_script_dirname(script))
+        if rc != 0:
+            print(name + ' generator dirty')
+            # Don't set any_dirty as we don't need git cl format in this case.
+            hashless_generators_dirty = True
+
+            if not args.verify_only:
+                print('Running ' + name + ' code generator')
+                subprocess.check_call(cmd, cwd=get_child_script_dirname(script))
+
     if args.verify_only:
-        sys.exit(any_dirty)
+        return int(any_dirty or hashless_generators_dirty)
 
     if any_dirty:
         args = ['git.bat'] if os.name == 'nt' else ['git']
@@ -273,6 +291,8 @@ def main():
                 json.dump(new_hashes, f, indent=2, sort_keys=True, separators=(',', ':\n    '))
                 f.write('\n')  # json.dump doesn't end with newline
 
+    return 0
+
 
 if __name__ == '__main__':
     sys.exit(main())