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wwstage: make the cgdot alias-peel struct-break module-aware (#223)

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The wwstage cgdot #191 alias-peel loop broke on a name-keyed any-module
structlookup, so a receiver whose alias name collides with a struct of the
same name in ANOTHER module resolved to the foreign struct and fell through to
an undefined `name(SB)` global instead of the field load. The eFinal FLIP
renames io's `vstream` -> `stream`, which collides with memio's `stream`
struct, so io.read/io.write/io.close's `match (s.reader)` emitted
`MOVQ reader(SB), AX` (reader is also a type-alias) -> cs != ww (cstage chases
the nominal TY_NAMED.under pointer chain, module-correct). Gate-blind: on
master both stages emit the same wrong store so byte-id stays green; the FLIP
corpus is the first to put the io-alias/memio-struct collision in one build.

Fix (wwstage-only align-down; cstage is the authority and is untouched): make
the peel's struct-break MODULE-AWARE — break only on a same-module struct (a
genuine struct-value receiver); a same-module alias keeps peeling to its
underlying (io.stream -> *vtable -> the pointer field-load arm); a foreign leaf
keeps the prior any-module heuristic. New structsamemod / aliassamemod mirror
the same-module-first pass already in structlookup / aliaslookup. This is not a
naive alias-first reorder (which would reintroduce the mirror collision: a
same-module struct plus a foreign same-leaf alias). Peel-only — the direct-
struct arm's broader cross-module same-leaf-STRUCT name-keying is filed as #224.

#208-family (name-keyed resolution dropping to a wrong global) but in cgen, not
the checker; #213 is distinct (cosmetic local-struct-match divergence).

test/wcc/784_xmod_alias_struct_collide_run: collision (cross-module alias-vs-
struct, same leaf), symmetric (guards the same-module-struct break against a
naive reorder), and a no-collision control — branched callee. The discriminating
net is cs.s == ww.s (the path is gate-blind and cstage is correct, so byte-id
flips when wwstage is fixed); confirmed by source-revert. The FLIP's combined.ww
is now cs.s == ww.s byte-identical.
This commit is contained in:
Hojun-Cho
2026-05-30 02:00:07 +09:00
parent 1175711021
commit 80184a3acf
7 changed files with 528 additions and 9 deletions
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12
Makefile
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@@ -335,6 +335,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_fmt_vstream_compositions_run \
$(BIN)/test_fieldfn_leaf_collide_run \
$(BIN)/test_amp_fn_assign_run \
$(BIN)/test_xmod_alias_struct_collide_run \
$(BIN)/test_bufio_vstream_run \
$(BIN)/test_log_vstream_run \
$(BIN)/test_use_promote_alias \
@@ -728,6 +729,17 @@ $(BIN)/test_amp_fn_assign_run: test/wcc/783_amp_fn_assign_run.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
# #223: a struct-field access through a pointer-ALIAS receiver whose
# leaf collides with another module's same-leaf STRUCT. cstage driver
# build + run for runtime, raw w6c vs w6c_ww .s cmp on the combined.ww
# for rule-10 byte-id (the #223 discriminator). Builds its own 2-module
# fixtures in a private mktemp dir — not a selfhost-driver test.
$(BIN)/test_xmod_alias_struct_collide_run: test/wcc/784_xmod_alias_struct_collide_run.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/w6c_ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_fmt_vstream_mods_run: test/wcc/780_fmt_vstream_mods_run.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \