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

matherr.obj exact-match log

Plain-English behavior

This CRT hook declines to handle a floating-point library error by returning zero. The translation unit also owns the initialized matherr_flag value 9876.

Provenance and reconstruction

• January target: one three-byte cdecl function and one four-byte .data object.
• Compiler: XDK 3911 CL 13.00.9254.1 with the libcmt project's unchanged /O1 /Gy flags.
• _matherr is deliberately declared with an opaque _exception pointer; the unused structure's layout cannot affect this function and is not invented here.
• _matherr_flag = 9876 reproduces target bytes 94 26 00 00 and external symbol ownership.

Verification

The object is admitted only if the hardened comparator proves the function's size, normalized bytes, and relocations, and a section audit proves the exact .data bytes and external symbol identity. No assembly, volatile, forced inlining, undefined behavior, byte patch, or compiler-flag change is used.

Current-campaign strict result

The older source was treated only as a lead. It was transplanted onto campaign tip ff944787, configured anew, and rebuilt independently with XDK 3911 before admission. The fresh result is exact:

Section	Target/candidate size	Relocations	SHA-256
__matherr .text	3/3	0/0	4bc724f3...f755e
_matherr_flag .data	4/4	0/0	ee668c09...3c865

Both objects expose __matherr as an external function at offset zero with type 0x20, and both expose __matherr_flag as an external data symbol at offset zero. The .text flags are 0x60101020; the .data flags are 0xC0300040. The initialized bytes are exactly 94 26 00 00 (9876 in little-endian order). Neither object owns .rdata or .bss.

House/Berth audit

• The intentionally unused exception argument keeps its opaque structure type; no unsupported field layout was invented.
• The function uses one direct readable return and the data declaration names the actual initialized CRT global.
• The decimal value 9876 is proven by the target data, not a codegen magic number or guessed engine constant.
• No assembly, volatile, undefined behavior, forced inlining, byte forcing, alignment override, compiler flag change, or comparator exception exists.
• This three-byte default hook contains no original-game bug requiring a fix note.

Admission additionally requires successful full Halo/libcmt builds, zero semantic unit errors, a clean forced-rebuild regression check, and all 179 project tool tests.