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

wcc/ww: match on a global value-struct tagged field reads g(SB) (#29)

Browse Source 
A match whose scrutinee is a tagged field of a GLOBAL value-struct read
the tag/payload from the BP region (saved-BP + return-addr) instead of
g(SB) and returned garbage. Both stages were identical-wrong, so the
byte-id gate could not see it -- a gate-blind regression introduced by
M1 (#25): M1's in-place N_DOT match arm uses localfind(base), which
returns the 0 not-found sentinel for a global base, so 0+field.offset
landed in the frame.

Gate the in-place arm on a confirmed-local base -- `localfind(base)==0
&& let_islet/isletvar(base)`, verbatim from cstage's own global test at
cgen.c:2000 (both stages, same spelling). A global base now falls
through to the existing spill path, which cgexprs the scrutinee and
resolves g(SB). M1's local-field in-place ($32) path is untouched.

Regenerates the w6c and wwdump combined.ww. Table-driven 841 test
(global int/reassign/str-payload + a local-field M1 regression row),
runtime-discriminating: pre-fix returns garbage, post-fix 42 on both
stages; rob's direct-global-field spill caveat confirmed at runtime.
This commit is contained in:
Hojun-Cho
2026-06-14 16:52:00 +09:00
parent 7a6b67fecc
commit c86c6a3bbf
6 changed files with 328 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
Makefile
View File

@@ -343,6 +343,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_tagged_widen_f64 \
$(BIN)/test_match_spill_pointer_payload \
$(BIN)/test_match_field_inplace \
$(BIN)/test_match_global_field \
$(BIN)/test_struct_byval_param \
$(BIN)/test_struct_multi_return_scratch \
$(BIN)/test_signed_data_emit \
@@ -2125,6 +2126,12 @@ $(BIN)/test_match_field_inplace: test/wcc/831_match_field_inplace.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_match_global_field: test/wcc/841_match_global_field.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_struct_byval_param: test/wcc/717_struct_byval_param.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \