test/wcc: extend carrier ownership to the bootstrap and platform gates

Same contract as the 27 repaired byte/artifact survivors: checked
acquisition, one all-exit cleanup funnel per carrier, ENOENT-tolerant
checked unlinks, exact-path deletion, and cleanup failure fails a
passing carrier without overwriting its diagnostic. Also closes the
vacuous-green channels: empty-artifact pairs no longer byte-compare
equal, capture and staging failures fail their row loudly, 950 requires
a clean checker exit on no-error rows and hard-fails on a missing
wwdump_ww, 992 keys its scratch per invocation so a failed cleanup
cannot leak stale objects into the next tool's compare, and 995 no
longer pre-sweeps a workdir it never created. No assertion is weakened;
990_selfhost is retired in the next commit rather than repaired.

test/wcc/993_ww_ww.c

@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
@@ -48,11 +49,14 @@ slurp_eq(const char *a, const char *b)
 	FILE *fb = fopen(b, "rb");
 	if (!fa || !fb) { if (fa) fclose(fa); if (fb) fclose(fb); return -1; }
 	int rc = 0;
+	int any = 0;
 	for (;;) {
 		int ca = fgetc(fa);
 		int cb = fgetc(fb);
 		if (ca != cb) { rc = -1; break; }
-		if (ca == EOF) break;
+		/* a produced executable can never be legitimately empty. */
+		if (ca == EOF) { if (!any) rc = -1; break; }
+		any = 1;
 	}
 	fclose(fa); fclose(fb);
 	return rc;
@@ -92,29 +96,35 @@ diff_one(const char *bin, const char *cwd, const char *label,
 	snprintf(dw, sizeof dw, "/tmp/ww_d_%d_w", getpid());
 
 	char cmd[256];
+	int rc = -1;
 	snprintf(cmd, sizeof cmd, "rm -rf %s %s && mkdir -p %s %s", dc, dw, dc, dw);
-	if (runwait(cmd) != 0) return -1;
+	if (runwait(cmd) != 0) goto cleanup;
 
 	if (build_via(bin, "ww",    src, dc, incs, out_basename) != 0) {
 		fprintf(stderr, "ww_ww FAIL: C ww errored on %s\n", label);
-		return -1;
+		goto cleanup;
 	}
 	if (build_via(bin, "ww_ww", src, dw, incs, out_basename) != 0) {
 		fprintf(stderr, "ww_ww FAIL: ww ww errored on %s\n", label);
-		return -1;
+		goto cleanup;
 	}
 
 	char co[1024], wo[1024];
 	snprintf(co, sizeof co, "%s/%s", dc, out_basename);
 	snprintf(wo, sizeof wo, "%s/%s", dw, out_basename);
 
-	int rc = 0;
-	if (slurp_eq(co, wo) != 0) {
+	if (slurp_eq(co, wo) != 0)
 		fprintf(stderr, "ww_ww FAIL: %s — driver outputs differ\n", label);
-		rc = -1;
-	}
+	else
+		rc = 0;
+
+cleanup:
+	/* `ww build` retains the caller-owned .sepwork tree inside the
+	 * workdir; rm -rf of the exact pid-keyed pair covers it, and is
+	 * safe even after a partial mkdir. */
 	snprintf(cmd, sizeof cmd, "rm -rf %s %s", dc, dw);
-	runwait(cmd);
+	if (runwait(cmd) != 0 && rc == 0)
+		rc = -1;
 	(void)cwd;
 	return rc;
 }
@@ -132,12 +142,21 @@ run_exit_code(const char *bin, const char *driver, int code)
 	if (!f) return -1;
 	fprintf(f, "package main;\nexport fn main() i32 = {\n\treturn %d;\n};\n",
 	    code);
-	fclose(f);
+	if (fclose(f) != 0) {
+		perror(src);
+		if (unlink(src) != 0 && errno != ENOENT)
+			perror(src);
+		return -1;
+	}
 
 	char cmd[256];
 	snprintf(cmd, sizeof cmd, "%s/%s run %s 2>/dev/null", bin, driver, src);
 	int rc = runwait(cmd);
-	unlink(src);
+	if (unlink(src) != 0 && errno != ENOENT) {
+		perror(src);
+		if (rc == code)
+			rc = -1;
+	}
 	return rc;
 }
 
@@ -152,14 +171,28 @@ run_build_fail(const char *bin, const char *driver)
 	char src[64];
 	snprintf(src, sizeof src, "/tmp/ww_badbuild_%d.ww", getpid());
 	FILE *f = fopen(src, "w");
-	if (!f) return -1;
+	if (!f) {
+		perror(src);
+		return -1;
+	}
 	wwtest_fputs("export fn main() i32 = {\n\treturn 1\n", f);	/* no ; no } */
-	fclose(f);
+	if (fclose(f) != 0) {
+		perror(src);
+		if (unlink(src) != 0 && errno != ENOENT)
+			perror(src);
+		return -1;
+	}
 
 	char cmd[256];
 	snprintf(cmd, sizeof cmd, "%s/%s run %s 2>/dev/null", bin, driver, src);
 	int rc = runwait(cmd);
-	unlink(src);
+	if (unlink(src) != 0 && errno != ENOENT) {
+		perror(src);
+		/* cleanup failure maps onto the -1 sentinel the caller rejects;
+		 * a real rc==0 (driver failed to fail) keeps its diagnostic. */
+		if (rc != 0)
+			rc = -1;
+	}
 	return rc;
 }
 
@@ -173,13 +206,21 @@ run_missing_pkg(const char *bin, const char *driver)
 {
 	char tmpdir[80], src[160], errf[160], outbin[160], rmcmd[200];
 	snprintf(tmpdir, sizeof tmpdir, "/tmp/ww_mp_%s_%d", driver, getpid());
-	mkdir(tmpdir, 0755);
+	if (mkdir(tmpdir, 0755) != 0) {
+		perror(tmpdir);
+		return 1;
+	}
 	snprintf(src,    sizeof src,    "%s/mp.ww", tmpdir);
 	snprintf(errf,   sizeof errf,   "%s/mp.err", tmpdir);
 	snprintf(outbin, sizeof outbin, "%s/mp", tmpdir);
 	snprintf(rmcmd,  sizeof rmcmd,  "rm -rf %s", tmpdir);
 	FILE *f = fopen(src, "w");
-	if (!f) { runwait(rmcmd); return 1; }
+	if (!f) {
+		perror(src);
+		if (runwait(rmcmd) != 0)
+			fprintf(stderr, "ww_ww: cleanup of %s failed\n", tmpdir);
+		return 1;
+	}
 	wwtest_fputs("import nosuchpkg;\nexport fn main() i32 = { return 0; };\n", f);
 	fclose(f);
 
@@ -200,12 +241,16 @@ run_missing_pkg(const char *bin, const char *driver)
 		buf[n] = '\0';
 		found = strstr(buf, "cannot find package nosuchpkg") != NULL;
 	}
-	runwait(rmcmd);
+	int cleanfail = runwait(rmcmd) != 0;
 	if (rc == 0 || !found) {
 		fprintf(stderr, "ww_ww FAIL: %s missing-pkg rc=%d found=%d "
 		    "(want nonzero + 'cannot find package')\n", driver, rc, found);
 		return 1;
 	}
+	if (cleanfail) {
+		fprintf(stderr, "ww_ww: cleanup of %s failed\n", tmpdir);
+		return 1;
+	}
 	return 0;
 }
 
@@ -232,7 +277,12 @@ main(void)
 		    "\tos.write(1, \"hi\\n\".ptr, 3u64);\n"
 		    "\treturn 0;\n"
 		    "};\n", f);
-		fclose(f);
+		if (fclose(f) != 0) {
+			perror(hello_src);
+			if (unlink(hello_src) != 0 && errno != ENOENT)
+				perror(hello_src);
+			return 1;
+		}
 	}
 
 	struct {
@@ -260,13 +310,17 @@ main(void)
 
 	int fail = 0;
 	int n = 0;
+	int cleanfail = 0;
 	for (int i = 0; cases[i].label; i++) {
 		if (diff_one(bin, cwd, cases[i].label, cases[i].src,
 		    cases[i].out, cases[i].incs) != 0)
 			fail++;
 		n++;
 	}
-	unlink(hello_src);
+	if (unlink(hello_src) != 0 && errno != ENOENT) {
+		perror(hello_src);
+		cleanfail = 1;
+	}
 
 	/* #16: `ww_ww run` must propagate the child program's real exit code.
 	 * Table-driven; the non-zero rows fail under the old collapse-to-1.
@@ -296,7 +350,9 @@ main(void)
 	 * failure (non-zero), and both drivers must agree. */
 	int cbad = run_build_fail(bin, "ww");
 	int wbad = run_build_fail(bin, "ww_ww");
-	if (cbad == 0 || wbad == 0 || cbad != wbad) {
+	/* <= 0 rejects the -1 staging/cleanup sentinel: equal sentinels must
+	 * not pass as build-fail parity when neither driver ever ran. */
+	if (cbad <= 0 || wbad <= 0 || cbad != wbad) {
 		fprintf(stderr, "ww_ww FAIL: build-fail exit C ww=%d ww_ww=%d "
 		    "(want equal and non-zero)\n", cbad, wbad);
 		rcfail++;
@@ -307,7 +363,7 @@ main(void)
 	rcfail += run_missing_pkg(bin, "ww");
 	rcfail += run_missing_pkg(bin, "ww_ww");
 
-	if (fail || rcfail) {
+	if (fail || rcfail || cleanfail) {
 		fprintf(stderr, "ww_ww: %d/%d diff(s) failed, %d exit-code "
 		    "row(s) failed\n", fail, n, rcfail);
 		return 1;