w6c_ww: cgtypetest resolves non-ident scrutinees, no-spill tag compare (fix #45)

Pre-#45 wwstage `is` resolved only N_IDENT scrutinees; xs[i] / p.field
/ call() fell through with scrutoff=0 + scrutt=nil and emitted
MOVQ (BP),AX; CMPQ $0,AX — tag read off the saved-BP word, variant
clamped to 0 (SILENT cs≠ww; cstage cgexprs the scrutinee and compares
the real tag in AX). The non-ident arm now cgexprs the scrutinee (tag
lands in AX) and compares directly. NOT the `as` twin's @asrt_spill
(#200): cmp against cstage shows N_TYPETEST never spills — `as`
re-reads payload words after the check, `is` consumes only the tag,
and a spill would break rule-10 byte-id. Variant index resolves from
the STAMPED scrutinee type via flatvariantidx/flatslicevariantidx
(matchscrutt's node walk can't carry N_DOT through cgtypetest's
N_TTAGGED gate). Ident path untouched (control row + hand-cmp vs
pre-#45 w6c_ww). wwstage-only source change; cs==ww byte-id pinned
per row in 927_is_nonident_run.
This commit is contained in:
2026-06-04 04:40:39 +09:00
parent c2308a11c7
commit b2e4388792
5 changed files with 365 additions and 12 deletions

View File

@@ -281,6 +281,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_sret_struct_return_run \
$(BIN)/test_tagged_sret_run \
$(BIN)/test_tagscr_sizes_run \
$(BIN)/test_is_nonident_run \
$(BIN)/test_global_sret_run \
$(BIN)/test_sret_narrow_field \
$(BIN)/test_sret_narrow_field_run \
@@ -1178,6 +1179,12 @@ $(BIN)/test_tagscr_sizes_run: test/wcc/926_tagscr_sizes_run.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_is_nonident_run: test/wcc/927_is_nonident_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_global_sret_run: test/wcc/940_global_sret_run.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \

View File

@@ -20261,6 +20261,7 @@ fn cgtypetest(c: *cgen, n: *node) void = {
};
let scrutoff: i32 = 0;
let scrutt: *node = nil;
let nonident: bool = false;
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT) {
let lc: *local = localfindnode(c, lhs.str);
@@ -20268,13 +20269,44 @@ fn cgtypetest(c: *cgen, n: *node) void = {
scrutoff = lc.off;
scrutt = resolvetagged(c, lc.tnode);
};
} else {
// #45: non-ident scrutinee (xs[i], p.field, call).
// cstage N_TYPETEST never spills — cgexpr leaves the
// scrutinee's tag word in AX (tagged element/field/
// call reads load the tag first), so compare AX
// directly. The `as` twin's @asrt_spill (#200) is
// NOT mirrored here: `as` re-reads payload words
// after the check; `is` consumes only the tag, and
// a spill would diverge from cstage's asm (rule 10).
// Pre-#45 this fell through to scrutoff=0 and the
// tag read landed on (BP) — the saved-BP word.
nonident = true;
cgexpr(c, lhs);
};
};
let want: i32 = cgtagvariantidx(c, scrutt, n.rhs);
let want: i32 = 0;
if (nonident) {
// Variant index from the STAMPED scrutinee type (cstage:
// u = n->lhs->type) — matchscrutt's node-shape walk can't
// carry N_DOT (returns the scrut node, which the
// cgtagvariantidx N_TTAGGED gate rejects). flatvariantidx /
// flatslicevariantidx read .type_ off any stamped carrier.
if (n.rhs != nil) {
if (n.rhs.kind == nkind.N_TSLICE) {
want = flatslicevariantidx(c, lhs, n.rhs.lhs);
} else {
want = flatvariantidx(c, lhs, n.rhs);
};
};
} else {
want = cgtagvariantidx(c, scrutt, n.rhs);
};
if (want < 0) { want = 0; };
emitline("\tMOVQ\t");
emitoff(scrutoff: i64);
emitline("(BP), AX\n");
if (!nonident) {
emitline("\tMOVQ\t");
emitoff(scrutoff: i64);
emitline("(BP), AX\n");
};
let nel: str = mklabel(c, "is_ne");
let dnl: str = mklabel(c, "is_done");
emitline("\tCMPQ\t$");

View File

@@ -402,6 +402,7 @@ fn cgtypetest(c: *cgen, n: *node) void = {
};
let scrutoff: i32 = 0;
let scrutt: *node = nil;
let nonident: bool = false;
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT) {
let lc: *local = localfindnode(c, lhs.str);
@@ -409,13 +410,44 @@ fn cgtypetest(c: *cgen, n: *node) void = {
scrutoff = lc.off;
scrutt = resolvetagged(c, lc.tnode);
};
} else {
// #45: non-ident scrutinee (xs[i], p.field, call).
// cstage N_TYPETEST never spills — cgexpr leaves the
// scrutinee's tag word in AX (tagged element/field/
// call reads load the tag first), so compare AX
// directly. The `as` twin's @asrt_spill (#200) is
// NOT mirrored here: `as` re-reads payload words
// after the check; `is` consumes only the tag, and
// a spill would diverge from cstage's asm (rule 10).
// Pre-#45 this fell through to scrutoff=0 and the
// tag read landed on (BP) — the saved-BP word.
nonident = true;
cgexpr(c, lhs);
};
};
let want: i32 = cgtagvariantidx(c, scrutt, n.rhs);
let want: i32 = 0;
if (nonident) {
// Variant index from the STAMPED scrutinee type (cstage:
// u = n->lhs->type) — matchscrutt's node-shape walk can't
// carry N_DOT (returns the scrut node, which the
// cgtagvariantidx N_TTAGGED gate rejects). flatvariantidx /
// flatslicevariantidx read .type_ off any stamped carrier.
if (n.rhs != nil) {
if (n.rhs.kind == nkind.N_TSLICE) {
want = flatslicevariantidx(c, lhs, n.rhs.lhs);
} else {
want = flatvariantidx(c, lhs, n.rhs);
};
};
} else {
want = cgtagvariantidx(c, scrutt, n.rhs);
};
if (want < 0) { want = 0; };
emitline("\tMOVQ\t");
emitoff(scrutoff: i64);
emitline("(BP), AX\n");
if (!nonident) {
emitline("\tMOVQ\t");
emitoff(scrutoff: i64);
emitline("(BP), AX\n");
};
let nel: str = mklabel(c, "is_ne");
let dnl: str = mklabel(c, "is_done");
emitline("\tCMPQ\t$");

View File

@@ -20261,6 +20261,7 @@ fn cgtypetest(c: *cgen, n: *node) void = {
};
let scrutoff: i32 = 0;
let scrutt: *node = nil;
let nonident: bool = false;
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT) {
let lc: *local = localfindnode(c, lhs.str);
@@ -20268,13 +20269,44 @@ fn cgtypetest(c: *cgen, n: *node) void = {
scrutoff = lc.off;
scrutt = resolvetagged(c, lc.tnode);
};
} else {
// #45: non-ident scrutinee (xs[i], p.field, call).
// cstage N_TYPETEST never spills — cgexpr leaves the
// scrutinee's tag word in AX (tagged element/field/
// call reads load the tag first), so compare AX
// directly. The `as` twin's @asrt_spill (#200) is
// NOT mirrored here: `as` re-reads payload words
// after the check; `is` consumes only the tag, and
// a spill would diverge from cstage's asm (rule 10).
// Pre-#45 this fell through to scrutoff=0 and the
// tag read landed on (BP) — the saved-BP word.
nonident = true;
cgexpr(c, lhs);
};
};
let want: i32 = cgtagvariantidx(c, scrutt, n.rhs);
let want: i32 = 0;
if (nonident) {
// Variant index from the STAMPED scrutinee type (cstage:
// u = n->lhs->type) — matchscrutt's node-shape walk can't
// carry N_DOT (returns the scrut node, which the
// cgtagvariantidx N_TTAGGED gate rejects). flatvariantidx /
// flatslicevariantidx read .type_ off any stamped carrier.
if (n.rhs != nil) {
if (n.rhs.kind == nkind.N_TSLICE) {
want = flatslicevariantidx(c, lhs, n.rhs.lhs);
} else {
want = flatvariantidx(c, lhs, n.rhs);
};
};
} else {
want = cgtagvariantidx(c, scrutt, n.rhs);
};
if (want < 0) { want = 0; };
emitline("\tMOVQ\t");
emitoff(scrutoff: i64);
emitline("(BP), AX\n");
if (!nonident) {
emitline("\tMOVQ\t");
emitoff(scrutoff: i64);
emitline("(BP), AX\n");
};
let nel: str = mklabel(c, "is_ne");
let dnl: str = mklabel(c, "is_done");
emitline("\tCMPQ\t$");

View File

@@ -0,0 +1,250 @@
/*
* 927_is_nonident_run — `e is T` on a NON-IDENT scrutinee (#45).
*
* Pre-#45 wwstage cgtypetest resolved ONLY lhs.kind == N_IDENT; every
* other scrutinee shape (xs[i], p.field, call()) fell through with
* scrutoff = 0 + scrutt = nil, emitting `MOVQ (BP), AX; CMPQ $0, AX`
* — the tag read landed on the saved-BP word and the variant index
* clamped to 0. SILENT cs≠ww miscompile (cstage N_TYPETEST cgexprs
* the scrutinee and compares the real tag in AX); the regex fold-2a
* epilogue guard `insts[insts.len-1] is inst_match` is the consumer
* that surfaced it. The `as` twin already had the non-ident
* @asrt_spill fallback (#200); `is` mirrors cstage's no-spill shape
* instead (only the tag word is consumed).
*
* Rows pin every scrutinee shape: indexed (constant and len-1 index),
* dot-field, call-result, the `is []T` slice-variant axis on an
* indexed scrutinee, and the ident control (asm hand-checked
* unchanged vs the pre-#45 compiler when the fix landed). Per row:
* w6c vs w6c_ww byte-id (rule 10 — cstage is the runtime-correct
* reference shape) + runtime via both the ww and ww_ww drivers.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>
static int
runwait(const char *cmd)
{
int rc = system(cmd);
if (rc == -1) return -1;
if (WIFEXITED(rc)) return WEXITSTATUS(rc);
return -1;
}
struct row {
const char *label;
const char *src;
int want;
};
#define P48_TYPES \
"type p48 = struct { a: i64, b: i64, c: i64, d: i64, e: i64, f: i64 };\n" \
"type small = (p48 | bool);\n"
static const struct row rows[] = {
/* The discovering repro: indexed scrutinee, constant and
* xs.len-1 index, asserted both polarities (a bool-built
* element must answer `is bool` true and `is p48` false —
* pre-#45 wwstage answered `is p48` TRUE, exit 2). */
{ "indexed",
P48_TYPES
"export fn main() i32 = {\n"
" let xs: []small;\n"
" let b: bool = true;\n"
" let v: small = b;\n"
" append(xs, v);\n"
" if (xs.len == 0 || !(xs[xs.len - 1] is bool)) {\n"
" return 1;\n"
" };\n"
" if (xs[xs.len - 1] is p48) {\n"
" return 2;\n"
" };\n"
" if (!(xs[0] is bool)) { return 3; };\n"
" return 0;\n"
"};\n",
0 },
/* Dot-field scrutinee. */
{ "dot_field",
P48_TYPES
"type holder = struct { v: small, k: i64 };\n"
"export fn main() i32 = {\n"
" let b: bool = true;\n"
" let h: holder = holder { v = b, k = 5 };\n"
" if (!(h.v is bool)) { return 1; };\n"
" if (h.v is p48) { return 2; };\n"
" return 0;\n"
"};\n",
0 },
/* Call-result scrutinee (register-class tagged return; the
* sret-class call stays #38b loud-stopped). */
{ "call_result",
"type val = (i64 | bool);\n"
"fn mk(flag: bool) val = {\n"
" if (flag) {\n"
" let b: bool = true;\n"
" return b;\n"
" };\n"
" let n: i64 = 7;\n"
" return n;\n"
"};\n"
"export fn main() i32 = {\n"
" if (!(mk(true) is bool)) { return 1; };\n"
" if (!(mk(false) is i64)) { return 2; };\n"
" if (mk(true) is i64) { return 3; };\n"
" return 0;\n"
"};\n",
0 },
/* `is []T` on an indexed scrutinee — the flatslicevariantidx
* axis of the non-ident variant resolution. */
{ "slice_variant_indexed",
"type val = (i64 | []u8);\n"
"export fn main() i32 = {\n"
" let xs: []val;\n"
" let buf: [2]u8 = [1u8, 2u8];\n"
" let s: []u8 = buf[0:2];\n"
" let v: val = s;\n"
" append(xs, v);\n"
" let n: i64 = 5;\n"
" let w: val = n;\n"
" append(xs, w);\n"
" if (!(xs[0] is []u8)) { return 1; };\n"
" if (!(xs[1] is i64)) { return 2; };\n"
" if (xs[0] is i64) { return 3; };\n"
" return 0;\n"
"};\n",
0 },
/* Ident control: the pre-existing slot-load path must be
* untouched (also hand-cmp'd vs the pre-#45 w6c_ww). */
{ "ident_control",
"type val = (i64 | bool);\n"
"export fn main() i32 = {\n"
" let b: bool = true;\n"
" let v: val = b;\n"
" if (!(v is bool)) { return 1; };\n"
" if (v is i64) { return 2; };\n"
" return 0;\n"
"};\n",
0 },
};
static const char *g_bin;
static int
compile_s(const char *tool, const char *src, const char *outpath)
{
char cmd[1024];
snprintf(cmd, sizeof cmd, "%s/%s %s > %s 2>&1",
g_bin, tool, src, outpath);
return runwait(cmd);
}
static int
file_eq(const char *a, const char *b)
{
char cmd[1024];
snprintf(cmd, sizeof cmd, "cmp -s %s %s", a, b);
return runwait(cmd) == 0;
}
static int
run_driver(const char *driver, const char *src, const char *label)
{
char tmpdir[128], cmd[1024];
snprintf(tmpdir, sizeof tmpdir, "/tmp/isnonid_%d_d", getpid());
mkdir(tmpdir, 0755);
snprintf(cmd, sizeof cmd, "cd %s && %s/%s build %s >/dev/null 2>&1",
tmpdir, g_bin, driver, src);
if (runwait(cmd) != 0) {
fprintf(stderr, "row[%s]: build via %s failed\n",
label, driver);
return -1;
}
const char *base = strrchr(src, '/');
base = base ? base + 1 : src;
char outbin[256];
snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
char *dot = strrchr(outbin, '.');
if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
int got = runwait(outbin);
unlink(outbin);
rmdir(tmpdir);
return got;
}
int
main(void)
{
const char *bin = getenv("BIN");
if (!bin) bin = "out/bin";
static char absbin[512];
if (bin[0] != '/') {
char cwd[256];
if (getcwd(cwd, sizeof cwd) == NULL) return 1;
snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
bin = absbin;
}
g_bin = bin;
int n = (int)(sizeof rows / sizeof rows[0]);
int total = 0, fail = 0;
for (int i = 0; i < n; i++) {
const struct row *r = &rows[i];
char src[128], cs_s[128], ww_s[128];
snprintf(src, sizeof src, "/tmp/isnonid_%d_%d.ww",
getpid(), i);
snprintf(cs_s, sizeof cs_s, "/tmp/isnonid_%d_%d_cs.s",
getpid(), i);
snprintf(ww_s, sizeof ww_s, "/tmp/isnonid_%d_%d_ww.s",
getpid(), i);
FILE *f = fopen(src, "wb");
if (!f) return 1;
fputs("package main;\n\n", f);
fputs(r->src, f);
fclose(f);
total++;
int cs_rc = compile_s("w6c", src, cs_s);
int ww_rc = compile_s("w6c_ww", src, ww_s);
if (cs_rc != 0 || ww_rc != 0) {
fprintf(stderr, "FAIL row[%s]: compile rc cs=%d "
"ww=%d\n", r->label, cs_rc, ww_rc);
fail++;
unlink(src); unlink(cs_s); unlink(ww_s);
continue;
}
if (!file_eq(cs_s, ww_s)) {
fprintf(stderr, "FAIL row[%s]: cs != ww .s\n",
r->label);
fail++;
}
int got_cs = run_driver("ww", src, r->label);
if (got_cs != r->want) {
fprintf(stderr, "FAIL row[%s] cstage: want %d "
"got %d\n", r->label, r->want, got_cs);
fail++;
}
char wwdrv[600];
snprintf(wwdrv, sizeof wwdrv, "%s/ww_ww", g_bin);
if (access(wwdrv, X_OK) == 0) {
int got_ww = run_driver("ww_ww", src, r->label);
if (got_ww != r->want) {
fprintf(stderr, "FAIL row[%s] wwstage: "
"want %d got %d\n",
r->label, r->want, got_ww);
fail++;
}
}
unlink(src); unlink(cs_s); unlink(ww_s);
}
if (fail) {
fprintf(stderr, "is_nonident_run: %d/%d rows failed\n",
fail, total);
return 1;
}
printf("is_nonident_run: %d rows ok\n", total);
return 0;
}