wcc/ww: compound OP= on a tagged index/ident is a loud reject (#20/#21)

Compound `OP=` through an index (gs[i]/a[i]) or a bare ident (g) on a
tagged union silently misbehaved: cstage dropped the index compound and
plain-stored, and BOTH stages compiled an ident compound into an add on
the tag word -- byte-identical, so the gate stayed green while the tag
was corrupted. A compound op on a whole union is nonsense.

Gate the index plain-store arm on TK_ASSIGN so a compound falls to the
existing #133 reject (wwstage's byte-id twin); add a dedicated #21 ident
reject in both stages. This closes the compound half of the tagged-payload
write class (deref #18, dot #34 already reject).

#19 (global tagged-array static-init DATA) is a separate emitter, still open.
This commit is contained in:
2026-06-14 01:14:51 +09:00
parent 769be55905
commit 33f940e17c
6 changed files with 427 additions and 2 deletions

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@@ -254,6 +254,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_unknowndecl_reject \
$(BIN)/test_nullableglobal_reject \
$(BIN)/test_taggedcompoundderef_reject \
$(BIN)/test_taggedcompoundplace_reject \
$(BIN)/test_idxarg_run \
$(BIN)/test_chainidx_run \
$(BIN)/test_tupfieldsize_run \
@@ -754,6 +755,24 @@ $(BIN)/test_taggedcompoundderef_reject: test/wcc/989_taggedcompoundderef_reject.
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
# 989_taggedcompoundplace_reject (#20/#21, last two members of the
# compound-OP-on-tagged-place reject class): `gs[i] OP= v` / `a[i] OP= v`
# (INDEX, #20) and `g OP= v` (IDENT, #21) on a tagged-union place are
# nonsense and must loud-reject. cstage silently dropped the indexed compound
# (cs!=ww); BOTH stages silently corrupted the tag word for the ident
# compound (byte-id-green). The fix gates the cstage indexed plain-store arm
# on TK_ASSIGN (compound falls to the #133 reject) and adds a tagged-ident
# compound guard to both stages. Reject rows assert build-fail + the
# per-place-kind diagnostic (#133 for index, #21 for ident); control rows
# (scalar ident/index compound + plain tagged ident/local-index/global-index
# store) build + run. Needs both tool sets + libwwrt for the control links.
$(BIN)/test_taggedcompoundplace_reject: test/wcc/989_taggedcompoundplace_reject.c \
$(BIN)/ww $(BIN)/ww_ww \
$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
# 989_idxarg_run (F7-c2, #45/#46): an indexed slice/str element passed as
# a call arg must push its full multi-word header. Builds+runs each fixture
# on BOTH the cstage `ww` and wwstage `ww_ww` drivers (rule-10), so it needs

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@@ -6483,8 +6483,16 @@ cgexpr(Cg *c, Node *n, Local *locals)
* the full cg_widen_tagged_store machinery — scalar /
* str / struct / subset payloads, tag remap, nullable
* fold — without duplicating it. The scratch lives in
* the function frame; no cleanup needed. */
if ((is_arr || is_sl || is_ptr) && elem_tagged) {
* the function frame; no cleanup needed.
* #20: only a PLAIN `=` widens. A COMPOUND `gs[i] OP= v`
* on a tagged element is nonsense — without the
* TK_ASSIGN gate it dropped the OP and plain-stored the
* RHS (silent miscompile, cs!=ww). The gate lets a
* compound fall to the #133 indexed-compound arm below,
* whose elem_tagged guard rejects loud (the byte-id
* twin of wwstage, which already rejected via #133). */
if ((is_arr || is_sl || is_ptr) && elem_tagged
&& n->op == TK_ASSIGN) {
int ssz = esz;
int scr = cg_tagscr_slot(c, &locals, ssz);
ins2(c, A_XORQ, areg(D_AX), areg(D_AX));
@@ -6972,6 +6980,20 @@ cgexpr(Cg *c, Node *n, Local *locals)
break;
}
}
/* #21: a COMPOUND op on a whole tagged-union IDENT (`g OP= v`
* with g:(int|bool)) is nonsense — the ident load-combine-
* store tail below (the N_IDENT compound arm) reads and writes
* one word of the {payload,tag} box, corrupting the tag. Reject
* loud here, the ident twin of the #18 deref / #133 index
* rejects; the byte-id twin of the wwstage guard. Plain `=`
* (the tagged-ident reassign arm just below) is untouched. */
if (n->lhs && n->lhs->kind == N_IDENT && n->op != TK_ASSIGN
&& n->lhs->type) {
Type *itu = type_chase_named(n->lhs->type);
if (itu && itu->kind == TY_TAGGED)
fatal("ident compound on tagged not wired "
"(#21/rule-7)");
}
/* Plain `r = expr;` where r is a tagged-union local.
* Delegates to cg_widen_tagged_store: covers nullable fold,
* tagged→tagged (with tag remap), struct payload (ident or

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@@ -31677,6 +31677,25 @@ fn cgassign(c: *cgen, n: *node) void = {
};
};
};
// #21: a COMPOUND op on a whole tagged-union IDENT (`g OP= v`
// with g:(int|bool)) is nonsense — the ident load-combine-store
// tail below reads and writes one word of the {payload,tag} box,
// corrupting the tag. Reject loud here, the ident twin of the #18
// deref / #133 index rejects; the byte-id twin of the cstage
// guard. Plain `=` (the tagged-ident reassign arm just below) is
// untouched.
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT && n.op != tkind.TK_ASSIGN) {
let itu: *tinfo = tichase(lhs.type_: *tinfo);
if (itu != nil) {
if (itu.kind == tykind.TY_TAGGED) {
let m21: str = "ident compound on tagged not wired (#21/rule-7)\n";
os.write(2, m21.ptr, m21.len: u64);
os.exit(1);
};
};
};
};
// Tagged-union local reassignment: `r = expr;` where r has a
// tagged-union type. Delegate to cgwidentaggedstore (same path
// as cglet's tagged-init). Covers nullable fold, tagged source,

View File

@@ -8331,6 +8331,25 @@ fn cgassign(c: *cgen, n: *node) void = {
};
};
};
// #21: a COMPOUND op on a whole tagged-union IDENT (`g OP= v`
// with g:(int|bool)) is nonsense — the ident load-combine-store
// tail below reads and writes one word of the {payload,tag} box,
// corrupting the tag. Reject loud here, the ident twin of the #18
// deref / #133 index rejects; the byte-id twin of the cstage
// guard. Plain `=` (the tagged-ident reassign arm just below) is
// untouched.
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT && n.op != tkind.TK_ASSIGN) {
let itu: *tinfo = tichase(lhs.type_: *tinfo);
if (itu != nil) {
if (itu.kind == tykind.TY_TAGGED) {
let m21: str = "ident compound on tagged not wired (#21/rule-7)\n";
os.write(2, m21.ptr, m21.len: u64);
os.exit(1);
};
};
};
};
// Tagged-union local reassignment: `r = expr;` where r has a
// tagged-union type. Delegate to cgwidentaggedstore (same path
// as cglet's tagged-init). Covers nullable fold, tagged source,

View File

@@ -31677,6 +31677,25 @@ fn cgassign(c: *cgen, n: *node) void = {
};
};
};
// #21: a COMPOUND op on a whole tagged-union IDENT (`g OP= v`
// with g:(int|bool)) is nonsense — the ident load-combine-store
// tail below reads and writes one word of the {payload,tag} box,
// corrupting the tag. Reject loud here, the ident twin of the #18
// deref / #133 index rejects; the byte-id twin of the cstage
// guard. Plain `=` (the tagged-ident reassign arm just below) is
// untouched.
if (lhs != nil) {
if (lhs.kind == nkind.N_IDENT && n.op != tkind.TK_ASSIGN) {
let itu: *tinfo = tichase(lhs.type_: *tinfo);
if (itu != nil) {
if (itu.kind == tykind.TY_TAGGED) {
let m21: str = "ident compound on tagged not wired (#21/rule-7)\n";
os.write(2, m21.ptr, m21.len: u64);
os.exit(1);
};
};
};
};
// Tagged-union local reassignment: `r = expr;` where r has a
// tagged-union type. Delegate to cgwidentaggedstore (same path
// as cglet's tagged-init). Covers nullable fold, tagged source,

View File

@@ -0,0 +1,327 @@
/*
* 989_taggedcompoundplace_reject — #20/#21, the last two members of the
* "compound-OP on a whole tagged place" reject class (siblings: #18 deref,
* #34 dot). A compound-assign `place OP= v` where `place` has a tagged-union
* type is semantically nonsense — you cannot `+=` a whole tagged value — so
* it MUST be a loud compile-time reject on BOTH stages.
*
* Two place-kinds remained after #18 closed the deref member:
*
* INDEX (#20): `gs[i] OP= v` (global tagged array) / `a[i] OP= v` (local
* tagged array). cstage SILENTLY MISCOMPILED: its indexed-tagged element
* arm (cmd/w6c/cgen.c) had no `n->op == TK_ASSIGN` gate, so a compound
* dropped the OP and plain-stored `(tagged)v` (cs!=ww). wwstage already
* rejected via its #133 indexed-compound arm. The fix gates the cstage
* plain-store arm on TK_ASSIGN so a compound falls to the same #133
* indexed-compound reject — the byte-id twin of wwstage. cstage align-UP.
*
* IDENT (#21): `g OP= v` where g is a tagged-union local/global. BOTH
* stages SILENTLY MISCOMPILED, byte-identically — the ident
* load-combine-store tail read+wrote one word of the {payload,tag} box
* and ADDED to the TAG word (gate-blind, #17/#263-class). The fix adds a
* tagged-ident compound guard to BOTH stages (cmd/w6c/cgen.c and
* selfhost/cmd/wcc/cgenexpr.ww) that rejects loud.
*
* The reject diagnostics follow the established per-place-kind family
* (#34 "single-dot field ... (#34/rule-7)", #133 "indexed-lvalue ...
* (#133/rule-7)") rather than one uniform string: INDEX rows reach the
* #133 indexed-compound reject; IDENT rows reach the new #21 ident-compound
* reject. Each row carries its own diagnostic substring, asserted on every
* driver alongside rc!=0. cstage's fatal() prefixes "ww: " that err.ww does
* not — the same per-stage prefix asymmetry every both-stage reject carries;
* the matrix matches on the shared CORE substring only.
*
* Reject-matrix idiom (sibling 989_taggedcompoundderef_reject.c): a REJECT
* row must FAIL to build with its diagnostic on every driver; an ACCEPT
* control must build + run to its expected exit. Rows run on cstage `ww`
* and, when present, wwstage `ww_ww`; both must agree.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>
static const char *DIAG_INDEX = "indexed-lvalue compound on tagged element not wired (#133/rule-7)";
static const char *DIAG_IDENT = "ident compound on tagged not wired (#21/rule-7)";
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 expect_build; /* 1 = build+run to want_exit; 0 = must REJECT */
int want_exit;
const char *diag; /* reject rows only: required core substring */
};
/* `g` is a (int|bool) local; `g OP= 1` compounds the WHOLE tagged value. */
#define IDENTCOMPOUND(OP) \
"package main;\n" \
"export fn main() int = {\n" \
"\tlet g: (int | bool) = 7;\n" \
"\tg " OP " 1;\n" \
"\treturn 0;\n" \
"};\n"
/* a:[3](int|bool) local; `a[0] OP= 1` compounds the WHOLE tagged element. */
#define LIDXCOMPOUND(OP) \
"package main;\n" \
"export fn main() int = {\n" \
"\tlet a: [3](int | bool) = [1, 2, 3];\n" \
"\ta[0] " OP " 1;\n" \
"\treturn 0;\n" \
"};\n"
/* gs:[3](int|bool) global; `gs[0] OP= 1` compounds the WHOLE tagged element. */
#define GIDXCOMPOUND(OP) \
"package main;\n" \
"let gs: [3](int | bool) = [1, 2, 3];\n" \
"export fn main() int = {\n" \
"\tgs[0] " OP " 1;\n" \
"\treturn 0;\n" \
"};\n"
static const struct row rows[] = {
/* IDENT (#21) — every compound OP on a tagged local rejects on both
* stages (was a byte-identical tag-word corruption). */
{ "ident_pluseq", IDENTCOMPOUND("+="), 0, 0, NULL },
{ "ident_minuseq", IDENTCOMPOUND("-="), 0, 0, NULL },
{ "ident_stareq", IDENTCOMPOUND("*="), 0, 0, NULL },
{ "ident_pipeeq", IDENTCOMPOUND("|="), 0, 0, NULL },
{ "ident_careteq", IDENTCOMPOUND("^="), 0, 0, NULL },
{ "ident_lshifteq", IDENTCOMPOUND("<<="), 0, 0, NULL },
{ "ident_slasheq", IDENTCOMPOUND("/="), 0, 0, NULL },
/* IDENT (#21) — a tagged GLOBAL compound rejects too. */
{ "gident_pluseq", "package main;\n"
"let g: (int | bool) = 7;\n"
"export fn main() int = {\n"
"\tg += 1;\n"
"\treturn 0;\n"
"};\n", 0, 0, NULL },
/* INDEX (#20) — local tagged-array element compound rejects on both
* stages (cstage was silently dropping the OP, plain-storing the RHS). */
{ "lidx_pluseq", LIDXCOMPOUND("+="), 0, 0, NULL },
{ "lidx_minuseq", LIDXCOMPOUND("-="), 0, 0, NULL },
{ "lidx_pipeeq", LIDXCOMPOUND("|="), 0, 0, NULL },
{ "lidx_lshifteq", LIDXCOMPOUND("<<="), 0, 0, NULL },
/* INDEX (#20) — global tagged-array element compound rejects too. */
{ "gidx_pluseq", GIDXCOMPOUND("+="), 0, 0, NULL },
{ "gidx_stareq", GIDXCOMPOUND("*="), 0, 0, NULL },
{ "gidx_careteq", GIDXCOMPOUND("^="), 0, 0, NULL },
/* CONTROL — scalar IDENT compound (`g += 1` on g:int) still compiles +
* runs (the guard keys on a tagged type only). 7 += 1 -> 8. */
{ "scalar_ident_ok",
"package main;\n"
"export fn main() int = {\n"
"\tlet g: int = 7;\n"
"\tg += 1;\n"
"\treturn g;\n"
"};\n",
1, 8, NULL },
/* CONTROL — scalar INDEX compound (`a[0] += 1` on a:[3]int) still
* compiles + runs (the #133 arm wires the scalar element). 7 += 1 -> 8. */
{ "scalar_index_ok",
"package main;\n"
"export fn main() int = {\n"
"\tlet a: [3]int = [7, 0, 0];\n"
"\ta[0] += 1;\n"
"\treturn a[0];\n"
"};\n",
1, 8, NULL },
/* CONTROL — the #41/#32 PLAIN tagged-ident reassign still compiles +
* runs (only the COMPOUND form is nonsense; `g = v` widens). `g is int`
* -> 0. */
{ "plain_tagged_ident_ok",
"package main;\n"
"export fn main() int = {\n"
"\tlet g: (int | bool) = 7;\n"
"\tg = 9;\n"
"\tif (g is int) { return 0; };\n"
"\treturn 1;\n"
"};\n",
1, 0, NULL },
/* CONTROL — the #16 PLAIN tagged-index store (local) still compiles +
* runs (`a[0] = v` widens the element). `a[0] is int` -> 0. */
{ "plain_tagged_lidx_ok",
"package main;\n"
"export fn main() int = {\n"
"\tlet a: [3](int | bool) = [1, 2, 3];\n"
"\ta[0] = 9;\n"
"\tif (a[0] is int) { return 0; };\n"
"\treturn 1;\n"
"};\n",
1, 0, NULL },
/* CONTROL — the #16 PLAIN tagged-index store (global) still compiles +
* runs (`gs[0] = v` widens; the store precedes the read so the #19
* static-init gap is not exercised). `gs[0] is int` -> 0. */
{ "plain_tagged_gidx_ok",
"package main;\n"
"let gs: [3](int | bool) = [1, 2, 3];\n"
"export fn main() int = {\n"
"\tgs[0] = 9;\n"
"\tif (gs[0] is int) { return 0; };\n"
"\treturn 1;\n"
"};\n",
1, 0, NULL },
};
static int
run_build(const char *driver, const struct row *r, int i)
{
char src[64], tmpdir[64], cmd[1024];
snprintf(src, sizeof src, "/tmp/tcp_%d_%d.ww", getpid(), i);
snprintf(tmpdir, sizeof tmpdir, "/tmp/tcp_%d_d_%d", getpid(), i);
FILE *f = fopen(src, "wb");
if (!f) return -2;
fputs(r->src, f);
fclose(f);
mkdir(tmpdir, 0755);
snprintf(cmd, sizeof cmd, "cd %s && %s build %s 2>/dev/null",
tmpdir, driver, src);
int brc = runwait(cmd);
const char *base = strrchr(src, '/');
base = base ? base + 1 : src;
char outbin[128];
snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
char *dot = strrchr(outbin, '.');
if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
int got = -1;
if (brc == 0) got = runwait(outbin);
unlink(src); unlink(outbin); rmdir(tmpdir);
return brc == 0 ? got : -1;
}
/* A reject row must (a) fail to build and (b) emit its diagnostic core text.
* Returns 0 on the expected reject, -1 otherwise. */
static int
build_should_reject(const char *driver, const char *src, const char *diag, int i)
{
char s[64], tmpdir[64], errf[80], cmd[1280];
snprintf(s, sizeof s, "/tmp/tcq_%d_%d.ww", getpid(), i);
snprintf(tmpdir, sizeof tmpdir, "/tmp/tcq_%d_d_%d", getpid(), i);
snprintf(errf, sizeof errf, "/tmp/tcq_%d_%d.err", getpid(), i);
FILE *f = fopen(s, "wb");
if (!f) return -1;
fputs(src, f);
fclose(f);
mkdir(tmpdir, 0755);
snprintf(cmd, sizeof cmd, "cd %s && %s build %s 2>%s",
tmpdir, driver, s, errf);
int rc = runwait(cmd);
int have_diag = 0;
FILE *e = fopen(errf, "rb");
if (e) {
char buf[4096];
size_t n = fread(buf, 1, sizeof buf - 1, e);
buf[n] = '\0';
fclose(e);
have_diag = (strstr(buf, diag) != NULL);
}
unlink(s); unlink(errf);
const char *base = strrchr(s, '/');
base = base ? base + 1 : s;
char outbin[128];
snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
char *dot = strrchr(outbin, '.');
if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
unlink(outbin);
rmdir(tmpdir);
/* build must NOT succeed AND the diagnostic must appear. */
return (rc != 0 && have_diag) ? 0 : -1;
}
int
main(void)
{
const char *bin = getenv("BIN");
if (!bin) bin = "out/bin";
char absbin[1024];
if (bin[0] != '/') {
char cwd[1024];
if (getcwd(cwd, sizeof cwd) == NULL) return 1;
snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
bin = absbin;
}
char cdrv[1024], wdrv[1024];
snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
struct { const char *name; const char *drv; int gated; }
drivers[] = {
{ "cstage", cdrv, 0 },
{ "wwstage", wdrv, 1 },
{ NULL, NULL, 0 },
};
int n = (int)(sizeof rows / sizeof rows[0]);
int total = 0, fail = 0;
for (int d = 0; drivers[d].name; d++) {
if (drivers[d].gated && access(drivers[d].drv, X_OK) != 0) {
fprintf(stderr, "taggedcompoundplace_reject: skip %s (no %s)\n",
drivers[d].name, drivers[d].drv);
continue;
}
for (int i = 0; i < n; i++) {
total++;
if (rows[i].expect_build) {
int got = run_build(drivers[d].drv, &rows[i], i);
if (got != rows[i].want_exit) {
fprintf(stderr, "taggedcompoundplace_reject[%s][%s]: "
"exit=%d want=%d\n", drivers[d].name,
rows[i].label, got, rows[i].want_exit);
fail++;
}
} else {
const char *diag = rows[i].diag;
if (!diag)
diag = (strncmp(rows[i].label, "ident", 5) == 0
|| strncmp(rows[i].label, "gident", 6) == 0)
? DIAG_IDENT : DIAG_INDEX;
if (build_should_reject(drivers[d].drv, rows[i].src,
diag, 100 + i) != 0) {
fprintf(stderr, "taggedcompoundplace_reject[%s][%s]: "
"expected a loud reject with \"%s\"\n",
drivers[d].name, rows[i].label, diag);
fail++;
}
}
}
}
if (fail) {
fprintf(stderr, "taggedcompoundplace_reject: %d/%d fixtures failed\n",
fail, total);
return 1;
}
printf("taggedcompoundplace_reject: %d/%d ok\n", total, total);
return 0;
}