Hojun-Cho/ww
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

wcc/check: A7 honest-floor tagged-subset reject closes wide→narrow miscompile (wwstage)

Browse Source 
wwstage's tagged→tagged subset-assign arm accepted all (lenient escape), silently miscompiling implicit wide→narrow: a (int|bool|str) holding a str, assigned to (int|bool), ran the int arm and read the str pointer as int. cstage rejects loud; this escape was the lone divergence.

Replace the escape with cstage's subset walk (src ⊆ dst): a src variant is covered iff typeeqast matches (structural — []u8/nested/primitives) OR both are N_TNAME with equal leaf names. The leaf bridge covers cross-module forwards where a callee's bare inline-union variant (utf8's `done`) meets the consumer's qualified `utf8.done` — raw typeeqast can't, and the escape was masking it for every forward. Mirrors casecovers (check.ww:4136). cstage untouched (align-up); spread-bearing unions keep the escape (#199b orthogonal).

Honest floor: leaf-only defers true module identity to #10 — a callee's defining module for an inline-union return is unrecoverable at check-time (the call node is gone; #211 fnretlookupmod is cgen-only). Retained divergence = cross-module same-leaf-collision over-accept (absent from bootstrap), documented at the site and filed as #10-A7 / census cat-A.

Test 989_tagged_subset_reject is table-driven with composition-discriminating rows: []u8 subset (typeeqast-only), bare↔qualified xmod forward (leaf-only), xmod named genuine-absence (reject). 352 green; w6c unchanged, w6c_ww 4b4496b8→4b316f01.
This commit is contained in:
Hojun-Cho
2026-06-10 00:22:22 +09:00
parent 758d3ec8c3
commit fddd167ce8
5 changed files with 648 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
Makefile
View File

@@ -244,6 +244,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_arr_tagged_elem \
$(BIN)/test_arr_infer_len \
$(BIN)/test_arr_cap_reject \
$(BIN)/test_tagged_subset_reject \
$(BIN)/test_arr_ptr_global \
$(BIN)/test_def_arr_infer_len \
$(BIN)/test_def_arr_len \
@@ -663,6 +664,12 @@ $(BIN)/test_arr_cap_reject: test/wcc/817_arr_cap_reject.c $(BIN)/ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_tagged_subset_reject: test/wcc/989_tagged_subset_reject.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_arr_ptr_global: test/wcc/818_arr_ptr_global.c $(BIN)/ww \
$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \