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

selfhost+test: route composite CALL return through nodeisslice (#24)

Browse Source 
Wwstage call-arg-emit recognized slice args only when source was
IDENT/SLICE/CAST/DOT. For N_CALL returning []T the natural-push
fallthrough emitted one PUSHQ AX (lost .len/.cap) and cgcall's
pop-count under-drained by 2 words — corrupting R8/R9 and every
subsequent arg. Class A runtime miscompile with stack misalignment
and 3-POPs-of-garbage at the receiving call. Sister to #21
(tagged-CALL arg) but for plain []u8 slice, not tagged-variant —
wwstage's pushargsrev grew the tagged-CALL arm at #21 and never
grew the plain-composite arm.

Surfaced by lib/strings landing's `bytes.X(toutf8(in), p)` call
sites: 995_self_rebuild's wwstage rebuild tripped on byte-id
divergence at w6c_ww + wwdump_ww emit. 967_bytes_run was green
because `ww run` exercises the cstage path. Corpus-coverage-blind
on the wwstage side until lib/strings pulled the chain through
wwstage compilation.

Fix is minimal: `nodeisslice` (selfhost/cmd/wcc/cgenutil.ww) gains
an N_CALL arm structurally identical to the existing N_CALL arm in
`nodeisstr` (only swap: isslicetype for isstrtype). The downstream
natural-push slice path (PUSHQ CX/BX/AX, extra=2 pop-count) was
already correct — it just needed the N_CALL-of-slice-return shape
to be recognized as a slice. pushargsrev and cgcall untouched.

Polarity catalog: wwstage UNDER — missing N_CALL arm in slice
shape recognition. Convergence wwstage → cstage per rule 10
(cstage reads typed-AST `type_isslice` natively).

Tests:
  - 723_composite_call_arg pins the 3-PUSH order (CX, BX, AX)
    between `CALL view` and next CALL on canonical `f(g())` shape,
    plus cstage vs wwstage cmp -s byte-id.
  - 927_composite_call_arg_run runtime-pins 7 rows × 2 stages =
    14 fixtures: canonical, slice-CALL + let-slice (hasprefix
    shape), two composite-CALL args (arg-shift collision),
    middle-argpos, nested composite-in-composite, slice + scalar
    pop-count mix, tagged-CALL regression alongside (confirms
    #21 still holds).

95/95 ok. 995_self_rebuild stays green (ww2==ww3==ww4 byte-id).
This commit is contained in:
Hojun-Cho
2026-05-18 02:20:42 +09:00
parent 53c9e46c21
commit 0e2c6cd893
6 changed files with 570 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
Makefile
View File

@@ -250,6 +250,8 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_sret_struct_return_run \
$(BIN)/test_match_slice_variant \
$(BIN)/test_match_slice_variant_run \
$(BIN)/test_composite_call_arg \
$(BIN)/test_composite_call_arg_run \
$(BIN)/test_param_shadow_mod \
$(BIN)/test_localoff_scope \
$(BIN)/test_cast_enum_movl \
@@ -555,6 +557,16 @@ $(BIN)/test_match_slice_variant_run: test/wcc/926_match_slice_variant_run.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_composite_call_arg: test/wcc/723_composite_call_arg.c \
$(BIN)/w6c $(BIN)/w6c_ww | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_composite_call_arg_run: test/wcc/927_composite_call_arg_run.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_use_promote_alias: test/wcc/699_use_promote_alias.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(LIB)/libwwrt.a | $(BIN)