ww/test/wcc/692_dot_str_chained_arg.c

/*
 * 692_dot_str_chained_arg — pass `<expr>.strfield` as a call argument.
 *
 * Task #30: selfhost's `nodeisstr` surface check used `dotinnerstructptr`
 * to resolve the base of a chained N_DOT, which only walked *struct
 * fields — value-struct hops fell through. The call-arg path then
 * pushed only 1 word (`.ptr`) instead of 2 (`.ptr`+`.len`), silently
 * dropping the str length at the call site.
 *
 * Cstage was unaffected because its `node_isstr` reads `n->type` from
 * the checker rather than re-walking the AST. The bug only bit when
 * the wwstage was the driver — surfaced via task #29's parallel
 * slice-field fix when a chained-str test row failed only on wwstage.
 *
 * Each fixture passes a str header through a call and reads `.len`
 * on the callee side to prove both header words round-trip. Rows
 * cover:
 *   - chained `*T`-rooted through value-struct hop (`p.inner.s`)
 *     — the failing shape filed as #30
 *   - single dot through `*T` root (`p.s`)
 *     — pre-existing path; baseline / negative control
 *   - chained local-rooted value-struct (`o.inner.s`)
 *     — same surface gap as #30 but rooted at a local rather
 *       than a `*T` param
 *
 * Exercises both stages via `ww` (cstage) and `ww_ww` (wwstage).
 */
#include <stdio.h>
#include <stdlib.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[] = {
	/* Baseline: single dot through `*T` root. Pre-existing path —
	 * `nodeisstr` resolves the base local's `*T` tnode directly,
	 * no dot-chain walker involved. Pinned so a future refactor
	 * of either branch can't regress it silently. */
	{ "ptr_root_str_arg",
	  "type outer = struct { s: str, x: i32 };\n"
	  "fn slen(s: str) i32 = { return s.len: i32; };\n"
	  "fn main() i32 = {\n"
	  "    let o: outer; o.s = \"hello\";\n"
	  "    let p: *outer = &o;\n"
	  "    if (slen(p.s) != 5) { return 1; };\n"
	  "    return 42;\n"
	  "};\n",
	  42 },
	/* #30 repro: chained through `*T` root with a value-struct
	 * hop. Without the fix, the wwstage pushed only `.ptr` —
	 * the called function then read whatever was in BX from the
	 * prior expression as the length. */
	{ "ptr_root_chained_str_arg",
	  "type inner = struct { s: str, pad: i32 };\n"
	  "type outer = struct { i: inner, tag: i32 };\n"
	  "fn slen(s: str) i32 = { return s.len: i32; };\n"
	  "fn main() i32 = {\n"
	  "    let o: outer; o.i.s = \"abcdef\";\n"
	  "    let p: *outer = &o;\n"
	  "    if (slen(p.i.s) != 6) { return 1; };\n"
	  "    return 42;\n"
	  "};\n",
	  42 },
	/* Local value-struct rooted, chained value-struct hop —
	 * same surface gap as the #30 repro above, but rooted on a
	 * local rather than a `*T` param. dotchainresolve walks
	 * both shapes; both go through the same fallback in
	 * `nodeisstr`. */
	{ "local_root_chained_str_arg",
	  "type inner = struct { s: str, pad: i32 };\n"
	  "type outer = struct { i: inner, tag: i32 };\n"
	  "fn slen(s: str) i32 = { return s.len: i32; };\n"
	  "fn main() i32 = {\n"
	  "    let o: outer; o.i.s = \"qrstuvw\";\n"
	  "    if (slen(o.i.s) != 7) { return 1; };\n"
	  "    return 42;\n"
	  "};\n",
	  42 },
};

static int
run_driver(const char *driver, const struct row *r, int i)
{
	char tmpdir[64], src[128], outbin[128], rmcmd[160], cmd[1024];
	snprintf(tmpdir, sizeof tmpdir, "/tmp/wdsc_%d_d_%d", getpid(), i);
	mkdir(tmpdir, 0755);
	snprintf(src, sizeof src, "%s/wdsc_%d_%d.ww", tmpdir, getpid(), i);
	snprintf(outbin, sizeof outbin, "%s/wdsc_%d_%d", tmpdir, getpid(), i);
	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);

	FILE *f = fopen(src, "wb");
	if (!f) { runwait(rmcmd); return -1; }
	fputs(r->src, f);
	fclose(f);

	snprintf(cmd, sizeof cmd, "%s build -o %s %s",
	    driver, outbin, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "row[%s]: build via %s failed\n",
		    r->label, driver);
		runwait(rmcmd);
		return -1;
	}

	int got = runwait(outbin);

	runwait(rmcmd);
	return got;
}

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];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	char wdrv[1024];
	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, "dot_str_chained_arg: 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,
				    "dot_str_chained_arg[%s][%s]: exit=%d want=%d\n",
				    drivers[d].name, rows[i].label,
				    got, rows[i].want);
				fail++;
			}
		}
	}
	if (fail) {
		fprintf(stderr,
		    "dot_str_chained_arg: %d/%d fixtures failed\n", fail, total);
		return 1;
	}
	printf("dot_str_chained_arg: %d/%d ok\n", total, total);
	return 0;
}