Drew T
2.7 KiB
§176d — THE CONFLICT TABLE MUST BE SEEDED FROM THE TU, AND KEYED PER FILE (P31 S52, 2026-08-15)
§176b's batch rule was right but under-scoped: it made drafts agree with each other and forgot the file they land in. Recovering the 11 conflict-dropped main drafts from waves J/K/L exposed both halves of the mistake, and the second one is the expensive one.
(a) Seed the symbol table from the DESTINATION TU, not from nothing. A draft can contradict a
declaration that is already in the .c — put there by a function banked three waves ago. Draft-vs-
draft comparison is blind to it, so the contradiction sails past the checker and surfaces only as a
compile error plus a bisect. Real case: src/800.c has carried extern void func_8001C9D0(void);
since func_8001C2C4 banked, while three wave-J drafts declared the same callee (s32) and
(void *). On the 11-draft recovery slate the TU-seeded check named 7 real conflicts the old
check missed entirely — and it found them iteratively: fixing one draft reveals the next
clash behind it, so re-run the dry run until it reports N -> N compatible, 0 dropped.
(b) Key the table PER DESTINATION FILE. A single slate-wide namespace makes two drafts landing
in different .c files illegally "conflict" over a symbol they are each entitled to declare
their own way. Separate TUs are separate namespaces (R39: over-refusal silently discards good work,
which is worse than letting a failure through to the gate that would catch it).
The recovery lever, extended — cast the CALLEE through a function pointer. §176b/§174-Law-4
covers adopting the TU's declaration for data and for your own parameters. The case they don't
cover: the TU prototypes a callee as taking no argument while your function must pass one. You
cannot pass an argument to a (void) prototype, and you must not change the TU's declaration
(other banked functions depend on it). Cast the function itself at the call site:
extern void func_8001C9D0(void); /* the TU's declaration, verbatim */
...
((void (*)(s32))func_8001C9D0)(a0); /* the call the target actually makes */
gcc-2.7.2 emits the identical jal with $a0 set — a direct call to a named symbol is unaffected
by the cast. All 11 recovered drafts re-verified MATCH after repair, across every variant used:
this function-pointer cast (×3), a pointer-type cast on an argument ((unsigned long *)), signed↔
unsigned data re-declaration (u16/s8, ×3), and array↔scalar (extern u8 D_x; + (u32)&D_x, ×3).
Zero of the eleven needed a codegen change — every one of them was a plumbing repair, which is
the standing P31 finding (matching-is-solved-integration-is-the-bottleneck) showing up once more.