port: advance VC6 typeobject frontier and preserve regression coverage

2026-10-26 18:09:33 +00:00
parent 35caf1a558
commit 5ab291a68c
162 changed files with 15675 additions and 85 deletions
@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+"""Guard _PyMem_DebugCheckAddress's C89 locals and validation order."""
+
+import re
+import sys
+from pathlib import Path
+
+source = Path(sys.argv[1]).read_text()
+match = re.search(
+    r"\n_PyMem_DebugCheckAddress\(const char \*func, char api, const void \*p\)\s*\{(.*?)\n\}",
+    source, re.S,
+)
+assert match, "_PyMem_DebugCheckAddress definition not found"
+body = re.sub(r"/\*.*?\*/", "", match.group(1), flags=re.S)
+declarations = """
+    const uint8_t *q;
+    size_t nbytes;
+    const uint8_t *tail;
+    int i;
+    char id;
+"""
+assert body.split()[:len(declarations.split())] == declarations.split(), (
+    "_PyMem_DebugCheckAddress must declare all locals without initializers at function entry"
+)
+
+# Keep the pointer cast after the assertion, and validate the leading pad
+# before reading the size or checking the tail of a possibly corrupt block.
+expected = declarations + """
+    assert(p != NULL);
+    q = (const uint8_t *)p;
+    id = (char)q[-SST];
+    if (id != api) {
+        _PyObject_DebugDumpAddress(p);
+        _Py_FatalErrorFormat(func,
+                             "bad ID: Allocated using API '%c', "
+                             "verified using API '%c'",
+                             id, api);
+    }
+    for (i = SST-1; i >= 1; --i) {
+        if (*(q-i) != PYMEM_FORBIDDENBYTE) {
+            _PyObject_DebugDumpAddress(p);
+            _Py_FatalErrorFunc(func, "bad leading pad byte");
+        }
+    }
+    nbytes = read_size_t(q - 2*SST);
+    tail = q + nbytes;
+    for (i = 0; i < SST; ++i) {
+        if (tail[i] != PYMEM_FORBIDDENBYTE) {
+            _PyObject_DebugDumpAddress(p);
+            _Py_FatalErrorFunc(func, "bad trailing pad byte");
+        }
+    }
+"""
+assert body.split() == expected.split(), (
+    "preserve _PyMem_DebugCheckAddress assertion, cast evaluation point, "
+    "and complete validation/diagnostic order"
+)
+print("obmalloc _PyMem_DebugCheckAddress C89 declarations and original validation order: PASS")