ww/test/wcc/794_xmod_ident_prefer.c

/*
 * 794_xmod_ident_prefer — project #55 close. Pins that the wwstage
 * checker resolves a BARE value-ident with same-MODULE preference
 * (selfhost/cmd/wcc/check.ww exprtype N_IDENT), mirroring cstage's
 * scope_lookup_prefer (cmd/wcc/check.c:66).
 *
 * THE BUG (wwstage-CHECKER-only, #55): exprtype's N_IDENT branch looked
 * a bare value-ident up via the flat-scope `scopelookup`, which bucket-
 * walks and returns whichever same-leaf symbol heads the bucket — the
 * LAST-registered one (scopedefineinmodule prepends). In a combined
 * unit the root `main` package registers last, so a bare `v` referenced
 * inside an IMPORTED module `aa` (curmod=aa) resolved to `main.v`, not
 * `aa.v` — dragging the wrong decl's type. cstage routes the same site
 * through scope_lookup_prefer(cur, cur_mod, name) and binds aa.v, so it
 * built fine; wwstage mis-typed the use and REJECTED. This is the
 * exprtype-N_IDENT member of the #55 bare-leaf cluster (sibling #56
 * fixed the N_CALL-callee path, #53 the bare-TNAME path).
 *
 * THE FIX (#55): scopelookup(c.cur, e.str) -> scopelookupprefer(c.cur,
 * c.curmod, e.str) at the single exprtype N_IDENT site.
 *
 * THE FIXTURE: `aa` exports a global `v: i32` and `fn getv() i32 =
 * { return v; }`. The root `main` declares a same-leaf `fn v() i64` and
 * calls aa.getv(). Registration order puts main.v (the i64 fn) at the
 * head of the flat-scope bucket, so a non-preferring lookup binds it.
 *   - cstage builds (prefer -> aa.v: i32, `return v` is i32) and runs:
 *     main returns aa.getv() == 7.
 *   - PRE-fix wwstage resolved `v` -> main.v (i64) and rejected
 *     `return: not assignable (i64 -> i32)` on the combined unit.
 *   - POST-fix wwstage prefers curmod=aa -> aa.v (i32) and ACCEPTS.
 *
 * DISCRIMINATOR (787 #13 model): the cstage driver emits the combined
 * unit (its checker is already correct), then we re-check that combined
 * with w6c_ww. PRE-fix it errored out (non-zero); POST-fix it succeeds.
 * w6c_ww REJECTING the combined is the #55 red.
 *
 * NOTE — no cs==ww byte-id assertion here, deliberately: a minimal
 * cross-module same-leaf VALUE-ident reference also trips a SEPARATE,
 * still-open cgen-side bare-leaf bug (cgenexpr.ww cgident likewise uses
 * the non-preferring scopelookup, so the value-load resolves the wrong
 * symbol/width), which would diverge the asm independently of this
 * CHECKER fix. The real #55 fmt manifestation flows through checker-
 * stamped tagged-union variant indices (not a value-load), so it does
 * not hit the cgen path; this minimal probe does, hence the reject->
 * accept polarity is the sound discriminator for the checker fix. The
 * cgen-side sibling is tracked separately (the #55 cluster residual).
 *
 * GATE POLARITY: must stay GREEN. Red means either the cstage routing
 * regressed (build/run) or wwstage rejected a valid same-module-preferred
 * ident again (w6c_ww rejects the combined).
 */
#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 file { const char *name; const char *src; };

static const struct file files[] = {
	{ "aa.ww",
	  "package aa;\n"
	  "export let v: i32 = 7;\n"
	  "export fn getv() i32 = {\n"
	  "	return v;\n"
	  "};\n" },
	{ "main.ww",
	  "package main;\n"
	  "import aa;\n"
	  "fn v() i64 = { return 100; };\n"
	  "export fn main() i32 = {\n"
	  "	return aa.getv();\n"
	  "};\n" },
	{ NULL, NULL }
};

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[2048];
	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 w6c[2100], w6c_ww[2100];
	snprintf(w6c, sizeof w6c, "%s/w6c", bin);
	snprintf(w6c_ww, sizeof w6c_ww, "%s/w6c_ww", bin);
	if (access(w6c_ww, X_OK) != 0) {
		fprintf(stderr, "794: w6c_ww missing — cannot run the wwstage "
		    "accept gate (the whole point of this test)\n");
		return 1;
	}

	char dir[] = "/tmp/ww794_XXXXXX";
	if (mkdtemp(dir) == NULL) {
		fprintf(stderr, "794: mkdtemp failed\n");
		return 1;
	}

	char path[1024], cmd[4096];
	int rc = 0;

	for (int i = 0; files[i].name; i++) {
		snprintf(path, sizeof path, "%s/%s", dir, files[i].name);
		FILE *f = fopen(path, "wb");
		if (!f) { fprintf(stderr, "794: write %s\n", files[i].name);
		    rc = 1; goto done; }
		fputs(files[i].src, f);
		fclose(f);
	}

	/* cstage driver build (prefer is correct) emits the combined unit. */
	snprintf(cmd, sizeof cmd, "cd %s && %s/ww build -I %s %s/main.ww",
	    dir, bin, dir, dir);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "794: cstage build failed\n");
		rc = 1; goto done;
	}
	/* cstage runtime pins the routing: main returns aa.getv() == 7. */
	snprintf(path, sizeof path, "%s/main", dir);
	int got = runwait(path);
	if (got != 7) {
		fprintf(stderr, "794: cstage exit %d, want 7\n", got);
		rc = 1; goto done;
	}

	char comb[1024];
	snprintf(comb, sizeof comb, "%s/main.combined.ww", dir);
	if (access(comb, 0) != 0) {
		fprintf(stderr, "794: no combined.ww emitted\n");
		rc = 1; goto done;
	}

	/* Sanity: cstage's own backend re-accepts its combined. */
	char cs_s[1024], ws_s[1024];
	snprintf(cs_s, sizeof cs_s, "%s/cs.s", dir);
	snprintf(ws_s, sizeof ws_s, "%s/ww.s", dir);
	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, cs_s, comb);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "794: w6c on combined failed\n");
		rc = 1; goto done;
	}

	/* The #55 discriminator: w6c_ww must ACCEPT the combined unit.
	 * PRE-fix it rejected (bare `v` -> main.v: i64 -> return mismatch);
	 * POST-fix it prefers curmod=aa -> aa.v: i32 and accepts. */
	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c_ww, ws_s, comb);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "794: w6c_ww REJECTED the combined (#55: bare "
		    "value-ident resolved the wrong module's same-leaf symbol)\n");
		rc = 1; goto done;
	}

done:
	snprintf(cmd, sizeof cmd, "rm -rf %s", dir);
	(void)runwait(cmd);
	if (rc) {
		fprintf(stderr, "794 xmod_ident_prefer: FAILED\n");
		return 1;
	}
	printf("xmod_ident_prefer: ok (cstage run==7 + w6c_ww accepts combined)\n");
	return 0;
}