wcc/ww: reject (a,) single-element trailing-comma tuple (catB-92)

wwstage's tuple-parse loop checked the RPAREN-break at the top, so
`(a,)` parsed as a 1-element N_TUPLE and reached cgen — a silent
wrong-accept. A trailing comma is legal only after >=2 elements.
Align the loop order to cstage cmd/wcc/parse.c:552-558 (parse each
element before the RPAREN-break); `(a,)` now errors at the next
parseexpr, `(a, b)` / `(a, b,)` are unchanged. cstage already
rejected; this brings wwstage's w6c_ww parser into agreement.

Regen w6c/wwdump combined.ww (parser embeds in both). Valid-program
codegen unchanged → cs==ww byte-id gate stays green.
This commit is contained in:
2026-06-15 03:49:38 +09:00
parent a8b43b8f4b
commit 6b7de54272
5 changed files with 208 additions and 3 deletions

View File

@@ -0,0 +1,186 @@
/*
* 845_tuple_trailing_comma_reject (catB-92) — cstage and wwstage
* LOUD-REJECT a single-element trailing-comma tuple `(a,)`.
*
* A trailing comma is legal ONLY after >=2 tuple elements; `(a,)` is a
* parse error, `(a, b)` and `(a, b,)` are 2-tuples. cstage parse.c:552-
* 558 parses each element BEFORE the RPAREN-break, so `(a,)` errors at
* the next parseexpr (it sees `)`). wwstage's lib/ww/parse/expr.ww tuple
* loop checked the RPAREN-break at the TOP, so `(a,)` parsed as a
* 1-element N_TUPLE and reached cgen — a silent wrong-accept. The fix
* mirrors cstage's loop order (break sits AFTER accept(COMMA)).
*
* The reject row is `let t = (5,);` — an INFERRED-type 1-tuple, the
* context the old wwstage built rc=0 and codegen'd (a 2-tuple-DECLARED
* `(5,)` already errored on arity downstream, masking the parse bug;
* the inferred form is the clean discriminator). Pre-fix wwstage built
* it rc=0; cstage rejected it. Post-fix both reject at parse.
*
* row | shape | expect
* -----------+-----------------+--------
* one_comma | let t = (5,); | REJECT (parse)
* two_elem | (3, 4) | BUILD, run 7
* two_comma | (3, 4,) | BUILD, run 7 (trailing OK after >=2)
*/
#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;
}
/* outbin — derive the driver's default binary name from a *.ww source
* (strip dir + the .ww suffix), placed in tmpdir. */
static void
outbin(char *dst, size_t n, const char *tmpdir, const char *src)
{
const char *base = strrchr(src, '/');
base = base ? base + 1 : src;
snprintf(dst, n, "%s/%s", tmpdir, base);
char *dot = strrchr(dst, '.');
if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
}
/* build_should_fail — returns 0 when the build correctly FAILS. */
static int
build_should_fail(const char *driver, const char *label, const char *src,
int i)
{
char s[64], tmpdir[64], cmd[1024], bin[128];
snprintf(s, sizeof s, "/tmp/tuptc_%d_%d.ww", getpid(), i);
snprintf(tmpdir, sizeof tmpdir, "/tmp/tuptc_%d_d_%d", 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>/dev/null",
tmpdir, driver, s);
int rc = runwait(cmd);
outbin(bin, sizeof bin, tmpdir, s);
unlink(s);
unlink(bin);
rmdir(tmpdir);
if (rc == 0)
fprintf(stderr, "tuptc[%s][%s]: built ok, expected a reject\n",
driver, label);
return rc == 0 ? -1 : 0;
}
/* run_build — build a program that MUST compile, run it, return exit. */
static int
run_build(const char *driver, const char *label, const char *src, int i)
{
char s[64], tmpdir[64], cmd[1024], bin[128];
snprintf(s, sizeof s, "/tmp/tuptc_ok_%d_%d.ww", getpid(), i);
snprintf(tmpdir, sizeof tmpdir, "/tmp/tuptc_ok_%d_d_%d", 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>/dev/null",
tmpdir, driver, s);
if (runwait(cmd) != 0) {
fprintf(stderr, "tuptc[%s][%s]: build failed (a valid tuple "
"must compile)\n", driver, label);
unlink(s); rmdir(tmpdir);
return -1;
}
outbin(bin, sizeof bin, tmpdir, s);
int got = runwait(bin);
unlink(s); unlink(bin); rmdir(tmpdir);
return got;
}
struct rejrow { const char *label; const char *src; };
static const struct rejrow reject_rows[] = {
{ "one_comma",
"package main;\n"
"fn main() i32 = { let t = (5,); return 0; };\n" },
};
struct okrow { const char *label; const char *src; int want; };
static const struct okrow ok_rows[] = {
{ "two_elem",
"package main;\n"
"fn pair() (i32, i32) = { return (3, 4); };\n"
"fn main() i32 = { let a, b = pair(); return a + b; };\n", 7 },
{ "two_comma",
"package main;\n"
"fn pair() (i32, i32) = { return (3, 4,); };\n"
"fn main() i32 = { let a, b = pair(); return a + b; };\n", 7 },
};
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 *path; int gated; } drivers[] = {
{ "cstage", cdrv, 0 },
{ "wwstage", wdrv, 1 },
{ NULL, NULL, 0 },
};
int nrej = (int)(sizeof reject_rows / sizeof reject_rows[0]);
int nok = (int)(sizeof ok_rows / sizeof ok_rows[0]);
int total = 0, fail = 0;
for (int d = 0; drivers[d].name; d++) {
if (drivers[d].gated && access(drivers[d].path, X_OK) != 0) {
fprintf(stderr, "tuptc: skip %s (no %s)\n",
drivers[d].name, drivers[d].path);
continue;
}
for (int i = 0; i < nrej; i++) {
total++;
if (build_should_fail(drivers[d].path,
reject_rows[i].label, reject_rows[i].src,
d * 100 + i) != 0)
fail++;
}
for (int i = 0; i < nok; i++) {
total++;
int got = run_build(drivers[d].path, ok_rows[i].label,
ok_rows[i].src, d * 100 + i);
if (got != ok_rows[i].want) {
fprintf(stderr, "tuptc[%s][%s]: exit=%d want=%d\n",
drivers[d].name, ok_rows[i].label,
got, ok_rows[i].want);
fail++;
}
}
}
if (fail) {
fprintf(stderr, "tuptc: %d/%d fixtures failed\n", fail, total);
return 1;
}
printf("tuptc: %d/%d ok\n", total, total);
return 0;
}