_Generic on a comparison matched NO association (hard error on valid C)

• Type: bug (compat — hard error, not silent)
• Track: C — C frontend (cparser.inc); tag: compat
• Status: done — fixed 2026-07-13.
• Found by: writing the regression for [[bug-c-generic-long-vs-int-ilp32]]; noted there as a separate gap and deliberately left out of that fix rather than widened into it.

Symptom

_Generic(i < 2, int: 1, long: 2)   /* error: no matching association and no default */

Same for !x, x && y, x || y. All valid C, all rejected.

Root cause

A comparison, !, and the logical operators yield an int in C (C11 6.5.8p6, 6.5.3.3p5). The frontend tags them tyBoolean internally, and CGScalarKindOfTk had no case for it — so the descriptor came out cgUnknown and matched nothing.

ParseCSizeof already treats this correctly (sizeof of a comparison is 4, with a comment saying so). The _Generic layer just never got the same mapping.

Fix

tyBoolean -> cgInt in CGScalarKindOfTk. C-mode only — the Pascal frontend never reaches this code, and nothing else consumes the cg descriptors.

Regression

Folded into test/cgeneric_long_rank_b250.c (same _Generic family) rather than a new file: comparison, !, &&, ||, and a comparison on a long all select int.

Gate

make test green, self-host byte-identical, testmgr --tier full 1203/1203.