[CI] (P13 W3b): retired-switch hygiene gate and the fatal census at its new floor

.github/workflows/test.yml

@@ -3548,6 +3548,12 @@ jobs:
       - name: Espryt memo-key purity check
         run: python3 scripts/ci/espryt_memo_purity.py --self-test
 
+      # P13 W3b: the pull build's switches stay retired - a preprocessor conditional on
+      # MOBILEGL_PIPE_PUSH / MOBILEGL_PIPE_LEGACY_MEMOS, or an MGB_CTX spelling, coming back is a
+      # red here. --self-test plants each shape first and requires the gate to catch it.
+      - name: Retired pull-build switches stay retired (P13)
+        run: python3 scripts/ci/retired_switches.py --self-test
+
       # The same question for the symbol tool the P1 gate is written in terms of.
       - name: Symbol report self-test
         run: python3 scripts/symbol_report.py --self-test

scripts/ci/fatal_census_baseline.json

@@ -1,7 +1,7 @@
 {
-  "abort_sites": 76,
+  "abort_sites": 75,
   "abort_sites_by_file": {
-    "MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp": 13,
+    "MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp": 12,
     "MobileGL/MG_Backend/DirectGLES/Managers.cpp": 12,
     "MobileGL/MG_Backend/DirectGLES/MultiDraw.cpp": 2,
     "MobileGL/MG_Backend/DirectGLES/Utils.cpp": 1,
@@ -66,7 +66,6 @@
     "UnmigratedPipeInput",
     "UnmigratedSurface",
     "UnmigratedVerb",
-    "UnnamedIdentity",
     "UnsetCallMask",
     "UnsizedReadback"
   ]

scripts/ci/retired_switches.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""P13 W3b: the pull build's switches stay retired.
+
+The pull build's macro (MOBILEGL_PIPE_PUSH as a preprocessor condition), the legacy-memo macro
+(MOBILEGL_PIPE_LEGACY_MEMOS) and the MGB_CTX spelling of the backends' context were removed in
+P13 W3b. Any of them coming back in source is a second arm nobody tests, so it is a red here.
+
+The RUNTIME MOBILEGL_PIPE_PUSH environment bitmask (bit 63 is still a switch, bits 0-13 are fixed
+on) is a different thing and is not matched: only a preprocessor conditional naming the macro is.
+
+Usage: retired_switches.py [--self-test]
+"""
+import pathlib
+import re
+import subprocess
+import sys
+
+ROOT = pathlib.Path(__file__).resolve().parents[2]
+CODE_GLOBS = ('*.cpp', '*.h', '*.hpp', '*.inc', '*.def', '*.c')
+RULES = (
+    (re.compile(r'^\s*#\s*(?:if|ifdef|ifndef|elif)\b.*\b(?:MOBILEGL_PIPE_PUSH|MOBILEGL_PIPE_LEGACY_MEMOS)\b'),
+     'a preprocessor conditional names a macro P13 W3b retired (MOBILEGL_PIPE_PUSH / '
+     'MOBILEGL_PIPE_LEGACY_MEMOS)'),
+    (re.compile(r'\bMGB_CTX(?:_LIVE|_IDENTITY)?\b'),
+     'MGB_CTX is back; backends read MG_Pipe::gPipeInputs directly since P13 W3b'),
+)
+
+
+def scan(files):
+    findings = []
+    for path, text in files:
+        for number, line in enumerate(text.splitlines(), start=1):
+            for pattern, message in RULES:
+                if pattern.search(line):
+                    findings.append(f'{path}:{number}: {message}: {line.strip()}')
+    return findings
+
+
+def tree_files():
+    names = subprocess.check_output(['git', 'ls-files', '--', *CODE_GLOBS], cwd=ROOT, text=True).split()
+    for name in names:
+        try:
+            yield name, (ROOT / name).read_text(encoding='utf-8', errors='replace')
+        except FileNotFoundError:
+            continue
+
+
+def self_test():
+    planted = [('planted.cpp', '#if MOBILEGL_PIPE_PUSH\nx();\n#endif\n'),
+               ('planted.h', '  #  elif !MOBILEGL_PIPE_LEGACY_MEMOS && FOO\n'),
+               ('planted.inc', 'auto v = MGB_CTX->GetX();\n'),
+               ('planted2.cpp', 'if (MGB_CTX_LIVE) {}\n')]
+    for item in planted:
+        assert scan([item]), f'the gate missed a planted line: {item}'
+    clean = [('clean.cpp', 'features.PipePush = QueryEnvUint64("MOBILEGL_PIPE_PUSH", 0x3fff);\n'),
+             ('clean.h', '// MOBILEGL_PIPE_PUSH=0x7f was the P2 mask\n'),
+             ('clean.inc', 'MG_Pipe::gPipeInputs.GetX();\n')]
+    for item in clean:
+        assert not scan([item]), f'the gate fired on a legitimate line: {item}'
+    print(f'retired switches self-test: {len(planted)} planted lines caught, {len(clean)} clean lines left alone')
+
+
+def main():
+    if '--self-test' in sys.argv[1:]:
+        self_test()
+    findings = scan(tree_files())
+    for line in findings:
+        print(f'::error::{line}')
+    if findings:
+        return 1
+    print('retired switches: none of MOBILEGL_PIPE_PUSH / MOBILEGL_PIPE_LEGACY_MEMOS (as #if) or MGB_CTX in source')
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())