Drew T
1.6 KiB
§121 — Synthesise externs for macro-DEFINED callees from the macro's own definition head (Phase 29 T95)
gather_externs carries a referenced symbol's declaration by copying a file-scope extern line out
of the exemplar TU. A shared engine function defined by a DEFINE_func_X() macro has no such
line anywhere — the macro defines it. The member TU instantiates that macro too, but frequently
below the splice point, so a draft that uses the symbol as a value (a cast call site,
((void(*)(void))func_80142C84)()) fails with undeclared (first use this function).
Guessing the type is worse than not declaring it. A no-prototype extern s32 func_80142C84();
turns the error into conflicting types against the macro's real void func_80142C84(s32 a0) — a
different error, which is the useful signal that the guess (not the diagnosis) was wrong.
The fix: macro_def_sig_map() parses the #define DEFINE_func_X() \ <ret> func_X(<params>) {
heads in engine_core.h (1,878 signatures) and the sweep prepends
extern <ret> func_X(<params>); for any referenced macro-defined callee the draft does not already
declare. Byte-verified on func_80142B2C: undeclared -> (bad guess) conflicting types ->
MATCH (34 ins) -> 136/136 banked.
Note this is the complement of header_sig_map(), which reads the extern decls a macro emits for
its own callees. Two different macro-derived signature sources; a symbol in neither is a real gap.
Blast radius: 0 beyond this family — like §118 and §120, and unlike §117, a targeted lever.