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

selfhost+test: zero-init !void / void-alias let-decl slots (#22)

Browse Source 
Wwstage's cglet skipped MOVQ $0 for sz=8 slots that cstage
zero-inits unconditionally — !void error types (utf8.invalid)
and void-alias variant tags (utf8.done / utf8.more) drifted
byte-id post-utf8 + lib/strings; promotes STATUS-3 #22 from
latent to bootstrap-blocking. Cstage emits MOVQ $0, -K(BP) in
the prologue for any sz=8 let-decl slot via the natural
type-fallthrough; wwstage's `typeis8byteprimitive` helper
returned false on N_TBANG and on N_TNAME pointing to an alias
that resolves to void, so the gate never fired and the slot
stayed uninitialised.

Polarity catalog: wwstage UNDER — `typeis8byteprimitive`
classifier too narrow at N_TBANG and void-alias N_TNAME.
Convergence wwstage → cstage's natural sz=8 fallthrough (rule
10). N_TBANG arm recurses on inner type (cmd/wcc/check.c:290
resolve_type copies T's kind, only sets iserror — so !T is
8B iff T is 8B); void-alias N_TNAME resolves through alias-
recursion the same way.

Tests:
  - 724_letdecl_zeroinit pins MOVQ $0, -K(BP) presence between
    function prologue and body on canonical !void and void-
    alias rows, plus cmp -s byte-id between stages per row.

Filed follow-up (NOT in scope here): #25 wwstage 8B struct
without rhs still under-emits (structlookup != nil short-
circuits the classifier). Same family as STATUS-4 #36 primsize
composite-aware sizing. No in-tree consumer.

96/96 ok. 995_self_rebuild stays green (ww2==ww3==ww4 byte-id).
This commit is contained in:
Hojun-Cho
2026-05-18 02:49:06 +09:00
parent 0e2c6cd893
commit c893c4bc37
5 changed files with 267 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
Makefile
View File

@@ -252,6 +252,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_match_slice_variant_run \
$(BIN)/test_composite_call_arg \
$(BIN)/test_composite_call_arg_run \
$(BIN)/test_letdecl_zeroinit \
$(BIN)/test_param_shadow_mod \
$(BIN)/test_localoff_scope \
$(BIN)/test_cast_enum_movl \
@@ -567,6 +568,10 @@ $(BIN)/test_composite_call_arg_run: test/wcc/927_composite_call_arg_run.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_letdecl_zeroinit: test/wcc/724_letdecl_zeroinit.c \
$(BIN)/w6c $(BIN)/w6c_ww | $(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)