selfhost: mirror @test runner via ww_ww (997_at_test_ww)

@test parsing already works under ww_ww (parseattrs lives in the
shared lib/ww/parse/decl.ww, picked up by both Cstage and wwstage),
so this is the test-side parity: 997 is 910 with `ww run` swapped
for `ww_ww run`, exercising the selfhost driver+compiler+assembler+
linker end-to-end on the same attest_pass.ww fixture. Suite is now
22 tests.

Makefile

@@ -215,7 +215,7 @@ TESTS	= $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
 	  $(BIN)/test_at_test \
 	  $(BIN)/test_selfhost $(BIN)/test_w6a_ww $(BIN)/test_w6l_ww \
 	  $(BIN)/test_w6c_ww $(BIN)/test_ww_ww $(BIN)/test_self_rebuild \
-	  $(BIN)/test_dyn_ww $(BIN)/test_selfcheck
+	  $(BIN)/test_dyn_ww $(BIN)/test_selfcheck $(BIN)/test_at_test_ww
 
 $(BIN)/test_smoke: test/wcc/000_smoke.c $(LIB)/libwcc.a | $(BIN)
 	$(CC) $(CFLAGS) $(INCS) -o $@ $< -L$(LIB) -lwcc
@@ -290,6 +290,10 @@ $(BIN)/test_dyn_ww: test/wcc/996_dyn_ww.c $(BIN)/ww $(BIN)/w6l $(BIN)/w6l_ww \
 		$(LIB)/libwwrt.a | $(BIN)
 	$(CC) $(CFLAGS) -o $@ $<
 
+$(BIN)/test_at_test_ww: test/wcc/997_at_test_ww.c $(BIN)/ww_ww $(BIN)/w6c_ww \
+		$(BIN)/w6a_ww $(BIN)/w6l_ww $(LIB)/libwwrt.a | $(BIN)
+	$(CC) $(CFLAGS) -o $@ $<
+
 test: all $(TESTS)
 	@WW=$(BIN)/ww BIN=$(BIN) sh test/run
 

test/wcc/997_at_test_ww.c

@@ -0,0 +1,170 @@
+/*
+ * 997_at_test_ww — same as 910_at_test, driven through `ww_ww`
+ * (the selfhost driver) instead of `ww` (the C driver). Confirms
+ * the ww-built toolchain parses, compiles, and runs an @test
+ * fixture end-to-end.
+ *
+ * Scanning is regex-free, matching the literal sequence
+ * `\n@test\s+fn\s+(IDENT)`. Same parser shape as ww accepts.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.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;
+}
+
+static int
+isws(int c)
+{
+	return c == ' ' || c == '\t' || c == '\n' || c == '\r';
+}
+
+static int
+isident(int c)
+{
+	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
+	    (c >= '0' && c <= '9') || c == '_';
+}
+
+/* find_attest — scan src for `@test\s+fn\s+(ident)`; on a match,
+ * write the identifier into `out` (NUL-terminated) and return the
+ * scan position past the matched ident. Returns -1 when no more. */
+static long
+find_attest(const char *src, long pos, char *out, size_t outsz)
+{
+	long n = (long)strlen(src);
+	while (pos < n) {
+		const char *q = strstr(src + pos, "@test");
+		if (q == NULL) return -1;
+		long off = q - src;
+		/* must be a top-level marker: previous non-space char is
+		 * '\n' or we're at the file start. */
+		long pre = off - 1;
+		while (pre >= 0 && (src[pre] == ' ' || src[pre] == '\t')) pre--;
+		if (pre >= 0 && src[pre] != '\n') {
+			pos = off + 1;
+			continue;
+		}
+		long c = off + 5;	/* past "@test" */
+		while (c < n && isws(src[c])) c++;
+		if (c + 2 > n || strncmp(src + c, "fn", 2) != 0) {
+			pos = off + 1;
+			continue;
+		}
+		c += 2;
+		if (c < n && isident(src[c])) {
+			pos = off + 1;
+			continue;
+		}
+		while (c < n && isws(src[c])) c++;
+		long ids = c;
+		while (c < n && isident(src[c])) c++;
+		if (c == ids) {
+			pos = off + 1;
+			continue;
+		}
+		size_t len = (size_t)(c - ids);
+		if (len + 1 > outsz) return -1;
+		memcpy(out, src + ids, len);
+		out[len] = '\0';
+		return c;
+	}
+	return -1;
+}
+
+static char *
+slurp(const char *path)
+{
+	FILE *f = fopen(path, "rb");
+	if (!f) return NULL;
+	fseek(f, 0, SEEK_END);
+	long n = ftell(f);
+	fseek(f, 0, SEEK_SET);
+	char *b = malloc((size_t)n + 1);
+	if (!b) { fclose(f); return NULL; }
+	if (fread(b, 1, (size_t)n, f) != (size_t)n) {
+		free(b); fclose(f); return NULL;
+	}
+	b[n] = '\0';
+	fclose(f);
+	return b;
+}
+
+static int
+runtests(const char *path, const char *bin)
+{
+	char *src = slurp(path);
+	if (!src) {
+		fprintf(stderr, "997 FAIL: cannot read %s\n", path);
+		return -1;
+	}
+
+	/* Build a synthetic test driver: original source + a main()
+	 * that calls each @test fn. Each test that runs to completion
+	 * (no abort/exit) counts as a pass. */
+	char tmpsrc[256];
+	snprintf(tmpsrc, sizeof tmpsrc, "/tmp/wwd_attest_ww_%d.ww", getpid());
+	FILE *out = fopen(tmpsrc, "wb");
+	if (!out) { free(src); return -1; }
+	fputs(src, out);
+	fputs("\nexport fn main() i32 = {\n", out);
+
+	long pos = 0;
+	int count = 0;
+	for (;;) {
+		char name[128];
+		long next = find_attest(src, pos, name, sizeof name);
+		if (next < 0) break;
+		fprintf(out, "\t%s();\n", name);
+		pos = next;
+		count++;
+	}
+	fputs("\treturn 0;\n};\n", out);
+	fclose(out);
+	free(src);
+
+	if (count == 0) {
+		fprintf(stderr, "997 FAIL: no @test fns found in %s\n", path);
+		unlink(tmpsrc);
+		return -1;
+	}
+
+	char cmd[2048];
+	snprintf(cmd, sizeof cmd, "%s/ww_ww run %s 2>/dev/null", bin, tmpsrc);
+	int rc = runwait(cmd);
+	unlink(tmpsrc);
+	if (rc != 0) {
+		fprintf(stderr, "997 FAIL: %s: %d @test fn(s), driver exited %d\n",
+		    path, count, rc);
+		return -1;
+	}
+	return count;
+}
+
+int
+main(void)
+{
+	const char *bin = getenv("BIN");
+	if (!bin) bin = "out/bin";
+	const char *files[] = {
+		"test/wcc/data/attest_pass.ww",
+		NULL,
+	};
+	int total = 0;
+	for (int i = 0; files[i]; i++) {
+		int n = runtests(files[i], bin);
+		if (n < 0) return 1;
+		total += n;
+	}
+	printf("@test (ww_ww): %d test(s) ran ok\n", total);
+	return 0;
+}