/*
 * 699_use_promote_alias — SK_USE→SK_X promotion preserves use_alias.
 *
 * Sweep of every reachable promotion site in cmd/wcc/check.c where an
 * SK_USE leaf gets in-place-promoted to a same-named decl. With driver
 * concatenation, the imported module's top-level decls appear in
 * file.list BEFORE the primary's `use foo;`, so pass-1 (N_USE +
 * N_TYPEDECL only) installs an SK_USE("foo") that pass-1.5 later
 * promotes when it walks the imported N_DEF / N_FNDECL / N_LET of the
 * same name. Each promotion must set `prev->use_alias = 1` so the
 * dot-prefixed lookups in resolve_typename (L77) and N_DOT (L709)
 * continue to walk the leaf as a module head.
 *
 * The fnmatch.flag-style "unknown type" failure that surfaced this is
 * the SK_FN row; the SK_TYPE row pins the random.random precedent
 * against regression; SK_DEF / SK_VAR are the same structural shape
 * with `def` / top-level `let` standing in for `fn`.
 *
 *   row  | imported decl shape         | path     | check.c line
 *   -----+-----------------------------+----------+-------------
 *   type | `type typmod = struct {...}`| L1660/77 | regression pin
 *   fn   | `fn fnmod() i32 = ...`      | L1722    | the bug
 *   def  | `def defmod: i32 = 0`       | L1709    | same shape
 *   var  | `let varmod: i32 = 0`       | L1736    | same shape
 *
 * Fixtures: test/wcc/data/usepromote/{type,fn,def,var}mod/<name>.ww
 * primary: test/wcc/data/usepromote/pos_{type,fn,def,var}.ww
 *
 * Each primary returns `flag.A` (= 42) so a successful build + run +
 * exit=42 proves the lookup chain end-to-end. Cstage-only: wwstage
 * uses a coexistence-not-promotion model in selfhost/cmd/wcc/check.ww
 * (separate sym entries differentiated by `mod`, no use_alias flag at
 * all), so the bug is structurally non-reachable on that side — see
 * the architectural note at installdecl in check.ww. Task #11 will
 * revisit when wwstage grows a real check pass on the cgen path.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.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;
}

static int
run_row(const char *driver, const char *fixdir, const char *tag)
{
	/* Keep the output and its caller-owned `<stem>.sepwork/` in one
	 * invocation-owned directory outside the repository. */
	char td[64];
	snprintf(td, sizeof td, "/tmp/usepr_%d_%s", getpid(), tag);
	if (mkdir(td, 0755) != 0) {
		fprintf(stderr, "use_promote_alias[%s]: mkdir %s: %s\n",
		    tag, td, strerror(errno));
		return 1;
	}

	char src[64];
	snprintf(src, sizeof src, "pos_%s.ww", tag);
	char bin[2048], sepdir[2048], rmcmd[2112];
	snprintf(bin, sizeof bin, "%s/out", td);
	snprintf(sepdir, sizeof sepdir, "%s.sepwork", bin);
	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", sepdir);
	char cmd[2048];
	int failed = 0, got;
	/* cd into the fixture dir so the driver's source-dir-first
	 * import search resolves `use <tag>mod;`; -o points OUT of the repo. */
	snprintf(cmd, sizeof cmd,
	    "cd %s && %s build -o %s %s >/dev/null 2>&1", fixdir, driver, bin, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr,
		    "use_promote_alias[%s]: build failed — SK_USE→SK_X "
		    "promotion likely dropped use_alias\n", tag);
		failed = 1;
		goto cleanup;
	}
	got = runwait(bin);
	if (got != 42) {
		fprintf(stderr,
		    "use_promote_alias[%s]: exit=%d want=42\n", tag, got);
		failed = 1;
	}

cleanup:
	{
		int cleanup_failed = 0;
		if (runwait(rmcmd) != 0) {
			fprintf(stderr, "use_promote_alias[%s]: remove %s failed\n",
			    tag, sepdir);
			cleanup_failed = 1;
		}
		if (unlink(bin) != 0 && errno != ENOENT) {
			fprintf(stderr, "use_promote_alias[%s]: unlink %s: %s\n",
			    tag, bin, strerror(errno));
			cleanup_failed = 1;
		}
		if (rmdir(td) != 0) {
			fprintf(stderr, "use_promote_alias[%s]: rmdir %s: %s\n",
			    tag, td, strerror(errno));
			cleanup_failed = 1;
		}
		if (!failed && cleanup_failed) failed = 1;
	}
	return failed;
}

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 fixdir[1024];
	if (getcwd(fixdir, sizeof fixdir) == NULL) return 1;
	size_t cwd_n = strlen(fixdir);
	const char *rel = "/test/wcc/data/usepromote";
	if (cwd_n + strlen(rel) + 1 >= sizeof fixdir) return 1;
	memcpy(fixdir + cwd_n, rel, strlen(rel) + 1);

	int fail = 0;
	fail += run_row(cdrv, fixdir, "type");
	fail += run_row(cdrv, fixdir, "fn");
	fail += run_row(cdrv, fixdir, "def");
	fail += run_row(cdrv, fixdir, "var");

	if (fail) {
		fprintf(stderr,
		    "use_promote_alias: %d row(s) failed\n", fail);
		return 1;
	}
	printf("use_promote_alias: 4/4 ok\n");
	return 0;
}