Cesarus85--mjolnir-vr/docs/object_matching_logs/libcmt_waccess_obj.md

libs/libcmt/waccess.obj exact-match ledger

Plain-English behavior

_waccess asks the Xbox CRT for a wide-character path's file attributes. If that query fails, it maps the operating-system error into the CRT error state and reports failure. If the caller requests write access to a read-only file, it explicitly records access-denied in both errno and _doserrno and reports failure. All other existing paths are considered accessible.

Scope and provenance

• Source: libs/libcmt/waccess.c.
• January target: libs/libcmt/waccess.obj, object index 809.
• Compiler: XDK 3911 CL 13.00.9254.1.
• Flags: unchanged libcmt project flags /O1 /Gy.
• Primary provenance: obj\\i386\\waccess.obj, extracted from the exact XDK 3911 libcmt.lib. It is strict-identical to January and its CodeView records name Microsoft's crtw32\\dos\\access.c, lines 68-89.
• Source-topology corroboration: the historical Xbox CRT access.c preserved in xerohour/xbox_leak_may_2020 at commit fd00b4b3b2abb1ea6ef9ac64b755419741a3af00. This corroborates names and the explicit final else; January bytes and the exact archive member remain the admission authority.

Validated baseline

The object was MISSING, unparked, and had no earlier source/log history or active lane. January owns one public function COMDAT and no runtime data:

Function	Size	Relocs	Normalized SHA-256	Relocation destinations
__waccess	69	5	7eafe1cffa2f12dc26924d279f72b4e8979c91c2fc1edbf4ab821f47cfacc2b4	___crtGetFileAttributesW, _GetLastError@0, __dosmaperr, __errno, ___doserrno

The first natural reconstruction had the correct 69-byte size and five relocations, but normalized hash 6d5f7cfcb40e80cba765a35e21cfa03f50697d7e5a27b4c0fb3d8973fd634a36. At +0x0D it selected the second return -1 as VC7's shared failure tail; January keeps the first failure tail and jumps backward to it from the read-only case. This shifted the final two call relocations two bytes earlier.

Accepted controls

• The attributes result is a 32-bit unsigned value, and invalid attributes is all bits set. These widths are proven by the exact XDK signature and January cmp eax,-1/test al,1 instructions.
• errno and _doserrno retain their historical CRT lvalue-macro topology, backed by the two exact accessor-call relocations.
• The final read-only/write test uses Microsoft's explicit if ... else return 0 topology. This changes no semantics, but it makes VC7 retain January's first failure tail. The exact archive's line table and recovered Microsoft source independently prove this is original structure rather than a code-generation trick.

Experiment matrix

ID	Source shape	Size T/B	Relocs T/B	Base hash / first divergence	Siblings	Decision
E00	Exact XDK archive member	69/69	5/5	target hash equal; none	1/1 exact	provenance accepted
E01	Two sequential natural failure guards, direct error accessors	69/69	5/5	6d5f7c...; +0x0D shared-tail representative	only function nonexact	rejected
E02	First guard followed by else if	69/69	5/5	identical to E01	only function nonexact	rejected
E03	Named shared-failure label and goto	69/69	5/5	identical to E01; optimizer folds label	only function nonexact	rejected
E04	Invert invalid test and nest valid path	69/69	5/5	e287af...; call-block order diverges at +0x0D	only function nonexact	rejected
E05	Historical errno/_doserrno lvalue macros but sequential final return	69/69	5/5	identical to E01	only function nonexact	macro topology retained, sequential return rejected
E05a	Add /Zd diagnostically to E01	69/69	5/5	identical to E01	only function nonexact	flag hypothesis falsified; production flags unchanged
E06	Historical lvalue macros plus explicit else { return 0; }	69/69	5/5	target hash equal; none	1/1 exact	retained

Whole-object ownership and alias audit

• Target and rebuilt object each own one 69-byte external .text COMDAT named __waccess, with five REL32 relocations at identical addresses, types, destinations, and addends.
• The public symbol has function type 0x20, external storage, and offset zero in its section. There are no aliases, private emitted helpers, or extra runtime functions.
• Neither object owns linked .rdata, .data, or .bss; there are no string, table, or data relocations to credit.
• Candidate debug and directive sections are compiler metadata and do not add linked runtime ownership.

Do-not-repeat list

• Do not remove the explicit final else. The recovered Microsoft source and measured E01-E06 matrix prove it controls the shared-tail representative.
• Do not retry else if, a named failure label, an inverted valid-path nest, or /Zd; their measured results are recorded above.
• Do not replace the two CRT error accessors with guessed globals, collapse the error paths, or reorder their assignments. Relocation identity and statement order are authoritative.
• Assembly, volatile, forced inline, optimizer pragmas, byte patches, undefined aliasing, altered production flags, and fuzzy credit are forbidden.

House-rule, Berth-rule, and bug audit

• The implementation is readable typed C, with vertically formatted parameters and descriptive names for the access mode, file attributes, and two error domains. It contains no anonymous offsets or unexplained literal flags.
• Multiple returns and the final else are retained because exact primary provenance proves them; forcing a generic single-exit house style would lose the January object.
• There is no assembly, volatile, forced inline, undefined behavior, alignment trick, flag override, raw object/tag cast, or byte-forcing cast.
• No original bug was found. The limited read-only/write check is documented historical CRT behavior and agrees with _waccess's intended contract, so a BUG (original) annotation would be unsupported.

Residual classification and disposition

There is no residual. The complete object is strict exact and is admitted as Matching.

Final validation

• Both halobetacache_build and libcmt_build completed successfully under the unchanged generated configuration and XDK 3911 toolchain.
• The regenerated report records libs/libcmt/waccess at 69/69 code bytes, 1/1 exact functions, no runtime data, and one complete unit. Overall progress at this lane was 317/833 objects; libcmt was 50/212 objects, 2,892/55,015 code bytes, and 53/476 functions.
• The semantic report scanned 420 units and 3,490 functions: 3,322 semantic exact, 93 hidden exact, 3,406 accepted exact, and zero unit errors.
• The admission audit found zero candidates and zero revocations. Its sole contradiction is the pre-existing unrelated source/shell/shell_xbox item.
• All 179 tooling tests passed. JSON parsing, the prohibited-construct scan, strict COFF recomparison, and git diff --check also passed.
• The clean-tree fail-closed regression gate reports __waccess still exact, with no changed-nonexact functions, newly-exact surprises, warnings, or failures.