wcc/ww: match on a global value-struct tagged field reads g(SB) (#29)
A match whose scrutinee is a tagged field of a GLOBAL value-struct read the tag/payload from the BP region (saved-BP + return-addr) instead of g(SB) and returned garbage. Both stages were identical-wrong, so the byte-id gate could not see it -- a gate-blind regression introduced by M1 (#25): M1's in-place N_DOT match arm uses localfind(base), which returns the 0 not-found sentinel for a global base, so 0+field.offset landed in the frame. Gate the in-place arm on a confirmed-local base -- `localfind(base)==0 && let_islet/isletvar(base)`, verbatim from cstage's own global test at cgen.c:2000 (both stages, same spelling). A global base now falls through to the existing spill path, which cgexprs the scrutinee and resolves g(SB). M1's local-field in-place ($32) path is untouched. Regenerates the w6c and wwdump combined.ww. Table-driven 841 test (global int/reassign/str-payload + a local-field M1 regression row), runtime-discriminating: pre-fix returns garbage, post-fix 42 on both stages; rob's direct-global-field spill caveat confirmed at runtime.
This commit is contained in:
266
test/wcc/841_match_global_field.c
Normal file
266
test/wcc/841_match_global_field.c
Normal file
@@ -0,0 +1,266 @@
|
||||
/*
|
||||
* 841_match_global_field — match on a tagged-union struct-FIELD of a
|
||||
* GLOBAL (module-level) VALUE struct: `match (g.t)`, g a `let g: box`.
|
||||
* Task #29.
|
||||
*
|
||||
* GATE-BLIND both-wrong regression from M1 (#25). M1 added an in-place
|
||||
* N_DOT match arm that points the dispatch slot at base.off +
|
||||
* field.offset, computing base.off via localfind. For a LOCAL base that
|
||||
* is the field's true frame slot ($32 in-place, correct). For a GLOBAL
|
||||
* base localfind returns its 0/not-found sentinel, so 0 + field.offset
|
||||
* lands in the saved-BP / return-addr region (BP+0/BP+8): both stages
|
||||
* emit `MOVQ (BP),AX` and read garbage. Both stages were identical-wrong
|
||||
* (byte-id GREEN), so only the RUNTIME oracle catches it — pre-fix
|
||||
* match(g.t) returns 213 instead of 42.
|
||||
*
|
||||
* Fix (both stages, rule 10): gate the in-place arm on a confirmed-LOCAL
|
||||
* base. A base is GLOBAL iff localfind(base)==0 && let_islet(base)
|
||||
* (cstage) / isletvar(c, base) (wwstage) — the same idiom cstage uses at
|
||||
* cgen.c:2000 (also 4707/4730/5393). A global base falls THROUGH to the
|
||||
* existing spill `else`, which cgexprs the scrutinee and resolves g(SB)
|
||||
* correctly. M1's LOCAL in-place path is unchanged (row (d) pins it).
|
||||
*
|
||||
* Rows pin the RUNTIME exit code on BOTH driver stages (cstage +
|
||||
* wwstage) — the discriminator is the value, not byte-id, since both
|
||||
* stages were identical-wrong. A cstage-vs-wwstage asm byte-identity
|
||||
* check is kept per row so the symmetric (rule-10) property stays pinned
|
||||
* after the guard lands in both stages.
|
||||
* (a) global VALUE-struct int-variant field [spill, g(SB)]
|
||||
* (b) global field bool->int payload remap [1-word variant]
|
||||
* (c) global field str-payload (24B box) [3-word variant]
|
||||
* (d) local VALUE-struct field, in place [M1 regression guard]
|
||||
*/
|
||||
#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; };
|
||||
|
||||
static const struct row rows[] = {
|
||||
/* (a) GLOBAL value struct, field set to the int variant in main,
|
||||
* matched. Pre-fix the in-place arm read BP+0 (213); post-fix the
|
||||
* spill path resolves g(SB) and returns 42. */
|
||||
{ "global_field_int",
|
||||
"package main;\n"
|
||||
"type box = struct { t: (int | bool), n: int };\n"
|
||||
"let g: box = box { t = 0, n = 5 };\n"
|
||||
"fn main() i32 = {\n"
|
||||
" g.t = 42;\n"
|
||||
" match (g.t) {\n"
|
||||
" case let n: int => return n: i32;\n"
|
||||
" case bool => return 1;\n"
|
||||
" };\n"
|
||||
"};\n",
|
||||
42 },
|
||||
/* (b) GLOBAL field reassigned, then matched; the int arm also reads
|
||||
* the sibling field g.n to prove the surrounding global is
|
||||
* undisturbed. Returns 7 + 5 = 12. The static initializer uses the
|
||||
* ZERO payload (t = 0): a nonzero tagged-field payload in a static
|
||||
* struct initializer trips a SEPARATE, deferred static-init DATA
|
||||
* divergence (task #19/#30 — wwstage drops the payload word to 0,
|
||||
* cstage emits it) that is orthogonal to the #29 match-cgen path
|
||||
* exercised here; a zero payload is byte-identical across stages. */
|
||||
{ "global_field_reassign_remap",
|
||||
"package main;\n"
|
||||
"type box = struct { t: (int | bool), n: int };\n"
|
||||
"let g: box = box { t = 0, n = 5 };\n"
|
||||
"fn main() i32 = {\n"
|
||||
" g.t = 7;\n"
|
||||
" match (g.t) {\n"
|
||||
" case let n: int => return (n + g.n): i32;\n"
|
||||
" case bool => return 1;\n"
|
||||
" };\n"
|
||||
"};\n",
|
||||
12 },
|
||||
/* (c) GLOBAL field, 24B str-payload variant (tag@+0, .ptr@+8,
|
||||
* .len@+16). Returns len("hello") = 5. */
|
||||
{ "global_field_str_payload_24B",
|
||||
"package main;\n"
|
||||
"type box = struct { t: (str | int), n: int };\n"
|
||||
"let g: box = box { t = 0, n = 5 };\n"
|
||||
"fn main() i32 = {\n"
|
||||
" g.t = \"hello\";\n"
|
||||
" match (g.t) {\n"
|
||||
" case let s: str => return len(s): i32;\n"
|
||||
" case int => return 99;\n"
|
||||
" };\n"
|
||||
"};\n",
|
||||
5 },
|
||||
/* (d) regression guard: a LOCAL value-struct field still reads in
|
||||
* place (M1's $32 path stays). Returns 42. */
|
||||
{ "local_field_inplace_guard",
|
||||
"package main;\n"
|
||||
"type box = struct { t: (int | bool), n: int };\n"
|
||||
"fn main() i32 = {\n"
|
||||
" let b: box = box { t = 0, n = 5 };\n"
|
||||
" b.t = 42;\n"
|
||||
" match (b.t) {\n"
|
||||
" case let n: int => return n: i32;\n"
|
||||
" case bool => return 1;\n"
|
||||
" };\n"
|
||||
"};\n",
|
||||
42 },
|
||||
};
|
||||
|
||||
static int
|
||||
run_driver(const char *driver, const struct row *r, int i)
|
||||
{
|
||||
char src[64], tmpdir[64], cmd[1024];
|
||||
snprintf(src, sizeof src, "/tmp/wcmgf_%d_%d.ww", getpid(), i);
|
||||
snprintf(tmpdir, sizeof tmpdir, "/tmp/wcmgf_%d_d_%d", getpid(), i);
|
||||
|
||||
FILE *f = fopen(src, "wb");
|
||||
if (!f) return -1;
|
||||
fputs(r->src, f);
|
||||
fclose(f);
|
||||
|
||||
mkdir(tmpdir, 0755);
|
||||
snprintf(cmd, sizeof cmd, "cd %s && %s build %s",
|
||||
tmpdir, driver, src);
|
||||
if (runwait(cmd) != 0) {
|
||||
fprintf(stderr, "row[%s]: build via %s failed\n",
|
||||
r->label, driver);
|
||||
unlink(src); rmdir(tmpdir);
|
||||
return -1;
|
||||
}
|
||||
|
||||
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 = runwait(outbin);
|
||||
|
||||
unlink(src); unlink(outbin); rmdir(tmpdir);
|
||||
return got;
|
||||
}
|
||||
|
||||
/* asm_byte_identical — the guard lands in BOTH stages, so cstage vs
|
||||
* wwstage text output must stay byte-for-byte identical on every row. */
|
||||
static int
|
||||
asm_byte_identical(const char *bin, const struct row *r, int i)
|
||||
{
|
||||
char src[64], cs[64], ws[64], cmd[1024];
|
||||
snprintf(src, sizeof src, "/tmp/wcmgf_asm_%d_%d.ww", getpid(), i);
|
||||
snprintf(cs, sizeof cs, "/tmp/wcmgf_asm_%d_%d_c.s", getpid(), i);
|
||||
snprintf(ws, sizeof ws, "/tmp/wcmgf_asm_%d_%d_w.s", getpid(), i);
|
||||
|
||||
FILE *f = fopen(src, "wb");
|
||||
if (!f) return -1;
|
||||
fputs(r->src, f);
|
||||
fclose(f);
|
||||
|
||||
snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
|
||||
if (runwait(cmd) != 0) {
|
||||
fprintf(stderr, "row[%s]: w6c errored\n", r->label);
|
||||
unlink(src);
|
||||
return -1;
|
||||
}
|
||||
snprintf(cmd, sizeof cmd, "%s/w6c_ww -o %s %s 2>/dev/null",
|
||||
bin, ws, src);
|
||||
if (runwait(cmd) != 0) {
|
||||
fprintf(stderr, "row[%s]: w6c_ww errored\n", r->label);
|
||||
unlink(src); unlink(cs);
|
||||
return -1;
|
||||
}
|
||||
|
||||
FILE *fc = fopen(cs, "rb");
|
||||
FILE *fw = fopen(ws, "rb");
|
||||
int rc = 0;
|
||||
if (!fc || !fw) {
|
||||
rc = -1;
|
||||
} else {
|
||||
for (;;) {
|
||||
int a = fgetc(fc);
|
||||
int b = fgetc(fw);
|
||||
if (a != b) { rc = -1; break; }
|
||||
if (a == EOF) break;
|
||||
}
|
||||
}
|
||||
if (fc) fclose(fc);
|
||||
if (fw) fclose(fw);
|
||||
if (rc != 0)
|
||||
fprintf(stderr, "row[%s]: cstage vs wwstage asm differs\n",
|
||||
r->label);
|
||||
unlink(src); unlink(cs); unlink(ws);
|
||||
return rc;
|
||||
}
|
||||
|
||||
int
|
||||
main(void)
|
||||
{
|
||||
const char *bin = getenv("BIN");
|
||||
if (!bin) bin = "out/bin";
|
||||
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;
|
||||
}
|
||||
|
||||
char cdrv[640];
|
||||
snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
|
||||
char wdrv[640];
|
||||
snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
|
||||
|
||||
struct { const char *name; const char *path; int gated_on_existence; }
|
||||
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_on_existence
|
||||
&& access(drivers[d].path, X_OK) != 0) {
|
||||
fprintf(stderr, "match_global_field: skip %s (no %s)\n",
|
||||
drivers[d].name, drivers[d].path);
|
||||
continue;
|
||||
}
|
||||
for (int i = 0; i < n; i++) {
|
||||
int got = run_driver(drivers[d].path, &rows[i], i);
|
||||
total++;
|
||||
if (got != rows[i].want) {
|
||||
fprintf(stderr,
|
||||
"match_global_field[%s][%s]: exit=%d want=%d\n",
|
||||
drivers[d].name, rows[i].label,
|
||||
got, rows[i].want);
|
||||
fail++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (access(wdrv, X_OK) == 0) {
|
||||
for (int i = 0; i < n; i++) {
|
||||
total++;
|
||||
if (asm_byte_identical(bin, &rows[i], i) != 0)
|
||||
fail++;
|
||||
}
|
||||
}
|
||||
|
||||
if (fail) {
|
||||
fprintf(stderr,
|
||||
"match_global_field: %d/%d fixtures failed\n",
|
||||
fail, total);
|
||||
return 1;
|
||||
}
|
||||
printf("match_global_field: %d/%d ok\n", total, total);
|
||||
return 0;
|
||||
}
|
||||
Reference in New Issue
Block a user