check: widen const def-ref to declared int type in def init (#113)

A def initializer whose rhs references another def -- `def INT_MIN: int
= I32_MIN;`, `def SIZE_MAX: size = U64_MAX;` -- failed to compile: an
N_IDENT->SK_DEF types as the referent's DECLARED type (i32, u64), so the
def-init assignability check (type_assignable) rejected i32 -> int /
u64 -> size, even though the value is a compile-time constant that fits.
This blocked faithful types/types::c limit defs (no cast in the Hare
source).

In a def initializer the rhs is a flexible constant. When it folds to a
compile-time integer (the #88 eval_def_const path: sibling/imported def
refs, casts, arithmetic) and the value fits the declared integer target,
re-flexibilize it to UNTYPED_INT so the existing untyped-int->typed
assignability path accepts it. This emulates Hare's flexible-constant
promotion (ICONST -> promote_flexible/lower_flexible,
ref/harec/src/types.c:860); def_cast_fits is the range check that keeps a
genuine out-of-range narrowing a loud "not assignable" error, never a
silent truncation (rule 7). It is strictly the const subset: the general
CONCRETE (non-const) integer widening Hare does at types.c:1021-1037 is
intentionally stricter in ww -- #115.

cstage-only: the wwstage checker (selfhost/cmd/wcc/check.ww, "let init /
return assignability") intentionally never checks def-init assignability
(it stays quiet, leaving full inference to the C side), so it never
rejected the widening -- the #88 stamp already laid the correct DATA row.
Relaxing the cstage aligns the richer side DOWN to the leaner side
(rule 10); both stages stamp the identical folded value, so emitted asm
is byte-identical. The bootstrap corpus has zero cross-prim-width def-ref
defs, so the new path is dead there and 990-997 are unperturbed.

Coverage: test/wcc/760_def_widen_const (i32->int neg, u64->size, byte-id
on each, cstage-only out-of-range narrowing fail-loud).
This commit is contained in:
2026-05-26 02:39:35 +09:00
parent 9a265a31f5
commit 5e4d67d90a
3 changed files with 355 additions and 11 deletions

View File

@@ -310,6 +310,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_localoff_scope \
$(BIN)/test_cast_enum_movl \
$(BIN)/test_check_enum_fold \
$(BIN)/test_def_widen_const \
$(BIN)/test_use_promote_alias \
$(BIN)/test_field_signed $(BIN)/test_frame_argcount \
$(BIN)/test_selfhost $(BIN)/test_w6a_ww $(BIN)/test_w6l_ww \
@@ -546,6 +547,12 @@ $(BIN)/test_check_enum_fold: test/wcc/759_check_enum_fold.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_def_widen_const: test/wcc/760_def_widen_const.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_arrlit_str_full: test/wcc/711_arrlit_str_full.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \