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

libs/libcmt/_wopen.obj exact-match ledger

This atomic lane starts from campaign commit 7d664c91. Before production edits it checked config/config.json, the parked ledger, all refs, worktrees, existing object logs, and active agent claims. The object was genuinely MISSING, unparked, absent from prior source/history, and unowned.

Plain-English behavior

_wopenfile turns a wide-character fopen mode such as L"rb+" into the low-level flags used by _wsopen. The first character selects read, write, or append. Later characters can select binary/text translation, read/write mode, commit behavior, sequential/random access, short-lived storage, or deletion on close. Duplicate mutually-exclusive modifiers stop the scan.

If the low-level open succeeds, the routine initializes the caller-provided FILE: it records the descriptor and stream flags, clears the buffer pointers and counters, and increments the CRT stream-cleanup count. It returns null when the leading mode is invalid or _wsopen fails.

Primary provenance and strict inventory

The exact member obj\i386\_wopen.obj was extracted from XDK 3911 libcmt.lib before reconstruction. Its CodeView records name both the specialization and Microsoft source template:

..\_wopen.c
d:\xbox-finalfre\private\sdktools\crt\crtw32\stdio\_open.c

The ordinary-C classification is therefore direct provenance, not an inference from disassembly. The pinned Microsoft XP-era CRT _open.c at Easy-Build-2k commit 36fce23389e43918faf4cd88688c64aa2668ff8f independently supplies the readable control-flow topology. January bytes, types, constants, and ownership remain authoritative where platform variants could differ.

The object owns one external pick-no-duplicates .text COMDAT and no runtime data:

• symbol: __wopenfile;
• size: 367 bytes (0x16F);
• relocations: 3;
• normalized SHA-256: 890c594f96b35c8cad75e91f6383d8303d09e82af4d5c5e36a1d0852751b8090;
• relocation destinations/addends: __commode + 0 at +0x14, __wsopen + 0 at +0x13F, and __cflush + 0 at +0x156.

The authentic archive member is independently strict-equal to the January target for the complete runtime section before its source form is used.

Experiment record

ID	One changed source factor	Result	Decision
E01	Faithful mode parser, but initialize the loop-validity flag at its declaration	375/367 bytes and 3/3 relocs; the flag spills as a third local, shifting relocations	Rejected
E02	Declare the loop-validity flag without an initializer, then assign 1 immediately before the parse loop, as in Microsoft _open.c	Exact 367/367, 3/3, normalized hash and relocation identity	Accepted

E02 explains the eight-byte E01 gap in ordinary source terms. Delaying the initial assignment shortens the flag's live range, so VC7 holds it in EDI and uses only two stack locals for the duplicate-option flags. This is a generally useful lifetime rule, not a register keyword or byte-forcing device.

Strict verification

XDK 3911 CL 13.00.9254.1 compiles the accepted source under the unchanged libcmt flags /O1 /Gy /I"xbox/include". The hardened comparator reports section_infos_equal: size, normalized bytes, all three relocation addresses, types, destinations, and addends match. Independent COFF inspection confirms the symbol storage class, COMDAT selection, and absence of .data, .rdata, or .bss ownership.

The fresh isolated lane then passed every required gate:

• the object was deleted and rebuilt, and both halobetacache_build and libcmt_build completed successfully;
• the regenerated report evaluated 3,579 functions in 460 units, accepted 3,495 exact functions, and reported zero unit errors;
• the admission audit found no new candidate, contradiction, or revocation for libs/libcmt/_wopen;
• campaign progress became 359/833 complete objects overall and 92/212 libcmt objects, with libcmt at 142/476 exact functions and 9,877/55,015 exact code bytes;
• all 179 tooling tests passed, configuration JSON parsed, the prohibited- construct scan was empty, and git diff --check was clean.

These figures come from the forced build in this lane; historical artifacts grant no credit. After rebasing onto campaign tip 08f86f9b, a second forced object build remained exact. The refreshed semantic report evaluated 3,586 functions in 461 units, accepted 3,502 exact functions, and still reported zero unit errors. The clean-commit regression snapshot/check classified __wopenfile as still_exact, with no changed nonexact functions, failures, or warnings.

House/Berth and bug audit

The source uses the XDK's FILE, wchar_t, and named _O_*/_IO* flags. Its parameters and calls are vertically formatted, variables have semantic names, and the control flow mirrors the CRT mode grammar rather than the disassembly. The two early null returns are justified by the target's distinct failure epilogue and keep the parser readable.

There is no assembly, volatile, forced inlining, undefined behavior, byte forcing, raw structure offset, compiler pragma, alignment trick, opaque codegen cast, compiler-flag change, or comparator exception. No independently actionable January bug was established: behavior for invalid extension text is part of the historical Microsoft CRT mode parser and is preserved without speculatively changing it.