ww/test/wcc/631_def_neg_global.c

/*
 * 631_def_neg_global — top-level `def X: T = N;` for non-trivially-
 * literal N. The pre-fix bug (#24): `def NEG: i32 = -100;` parsed
 * the rhs as N_UN(TK_MINUS, N_INTLIT) and both stages' emit_defs /
 * emitdefconstants skipped any non-leaf-literal shape — no DATA row
 * was emitted, and any reference to NEG failed to link with
 * "undefined reference". Workaround in tree had been bundling such
 * flags into an enum (see the `at` enum at lib/os/os.ww:393).
 *
 * The fix lifts the literal-fold core into a shared helper
 * (fold_int_literal / foldintliteral) that handles
 * INTLIT/RUNELIT/TRUE/FALSE/NIL plus a unary +/-/~ wrapper over the
 * same. emit_defs (cstage cmd/w6c/cgen.c) and emitdefconstants
 * (wwstage selfhost/cmd/wcc/cgen.ww) both gate on it. The shared
 * helper is reused by eval_enum_value / enumevalmember so the fold
 * logic lives in one place per stage.
 *
 * Rows pin:
 *   - negative-i32: the headline bug. exit=42.
 *   - positive-i32: regression check; the same emit path must still
 *     produce a DATA row for an unwrapped literal.
 *   - tilde-i32: unary ~ over N_INTLIT (the other op in the unary
 *     whitelist beyond TK_MINUS / TK_PLUS).
 *   - negative-i64: 8-byte slot via the same path; verifies sign
 *     extension through the i64 load.
 *   - negative-u32-cast: `def X: u32 = (-1): u32;` exercises an
 *     N_CAST wrapping the N_UN. The fold gate doesn't peel N_CAST
 *     — but cgen sees the cast and consumes it on the read side —
 *     so this is OUT OF SCOPE for the gate; we use u32 differently.
 *     Instead the u32 row uses a tilde to get the all-ones pattern:
 *     `def X: u32 = ~0u32;` truncates cleanly into a u32 slot and
 *     reads back as 0xFFFFFFFF.
 *   - unary-plus-i32: `def X: i32 = +5;` — TK_PLUS noop, completes
 *     the unary whitelist coverage.
 *
 * Per-fixture: compile+link+run via the `ww` driver (cstage) and
 * via `ww_ww` (wwstage) if it exists. Asm byte-identity diff between
 * cstage's w6c and wwstage's w6c_ww closes the symmetry corner.
 */
#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[] = {
	/* The headline #24 case: N_UN(TK_MINUS, N_INTLIT) rhs.
	 * Pre-fix this failed at link time with
	 * "undefined reference to '<tmpname>.NEG'". */
	{ "negative-i32",
	  "def NEG: i32 = -100;\n"
	  "fn main() i32 = {\n"
	  "\tlet x: i32 = NEG;\n"
	  "\tif (x == -100) { return 42; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  42 },

	/* Regression check: an unwrapped N_INTLIT rhs must still
	 * emit a DATA row. If the fold-gate rewrite accidentally
	 * narrows the whitelist, this row catches it. */
	{ "positive-i32",
	  "def POS: i32 = 100;\n"
	  "fn main() i32 = {\n"
	  "\tlet x: i32 = POS;\n"
	  "\tif (x == 100) { return 42; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  42 },

	/* Unary tilde over N_INTLIT — the other arithmetic op in
	 * the unary whitelist. ~0 is -1 in i32 two's complement;
	 * reading and comparing as i32 pins the slot's full
	 * sign-extended form. */
	{ "tilde-i32",
	  "def NTIL: i32 = ~0;\n"
	  "fn main() i32 = {\n"
	  "\tlet x: i32 = NTIL;\n"
	  "\tif (x == -1) { return 42; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  42 },

	/* 8-byte slot via the same fold path. Catches any width-
	 * specific bug in the DATA-row emit (DATA always writes
	 * 8 bytes; the i64 typed def is the natural cardinality
	 * match for that slot). */
	{ "negative-i64",
	  "def NEG: i64 = -1234567890i64;\n"
	  "fn main() i32 = {\n"
	  "\tlet x: i64 = NEG;\n"
	  "\tif (x == -1234567890i64) { return 42; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  42 },

	/* Unsigned (u32) slot. `~0u32` is all-ones; reading it
	 * back through a u32 local and comparing against the
	 * literal pins both the fold (TK_TILDE) and the
	 * sign-vs-zero-extend on load. */
	{ "tilde-u32",
	  "def UMAX: u32 = ~0u32;\n"
	  "fn main() i32 = {\n"
	  "\tlet x: u32 = UMAX;\n"
	  "\tif (x == 4294967295u32) { return 42; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  42 },

	/* Unary plus — TK_PLUS noop in the fold. Completes the
	 * unary whitelist coverage. */
	{ "unary-plus-i32",
	  "def P: i32 = +5;\n"
	  "fn main() i32 = {\n"
	  "\tlet x: i32 = P;\n"
	  "\tif (x == 5) { return 42; };\n"
	  "\treturn 1;\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/dng_%d_d_%d", getpid(), i);
	mkdir(tmpdir, 0755);
	snprintf(src, sizeof src, "%s/dng_%d_%d.ww", tmpdir, getpid(), i);
	snprintf(outbin, sizeof outbin, "%s/dng_%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 2>/dev/null",
	    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;
}

/* asm_byte_identical — generate .s via cstage's w6c and wwstage's
 * w6c_ww and diff. Pins the symmetric-emit contract: if either
 * stage's fold helper drifts (e.g. one accepts N_NIL the other
 * doesn't), the DATA row differs and ww2!=ww3 byte-id breaks. */
static int
asm_byte_identical(const char *bin, const struct row *r, int i)
{
	char src[64], cs[64], ws[64], cmd[1024];
	snprintf(src, sizeof src, "/tmp/dng_asm_%d_%d.ww", getpid(), i);
	snprintf(cs,  sizeof cs,  "/tmp/dng_asm_%d_%d_c.s", getpid(), i);
	snprintf(ws,  sizeof ws,  "/tmp/dng_asm_%d_%d_w.s", getpid(), i);

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

	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "row[%s]: w6c errored\n", r->label);
		unlink(src);
		return -1;
	}
	snprintf(cmd, sizeof cmd, "%s/w6c_ww -o %s %s 2>/dev/null",
	    bin, ws, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "row[%s]: w6c_ww errored\n", r->label);
		unlink(src); unlink(cs);
		return -1;
	}

	FILE *fc = fopen(cs, "rb");
	FILE *fw = fopen(ws, "rb");
	int rc = 0;
	if (!fc || !fw) {
		rc = -1;
	} else {
		for (;;) {
			int a = fgetc(fc);
			int b = fgetc(fw);
			if (a != b) { rc = -1; break; }
			if (a == EOF) break;
		}
	}
	if (fc) fclose(fc);
	if (fw) fclose(fw);
	if (rc != 0)
		fprintf(stderr, "row[%s]: cstage vs wwstage asm differs\n",
		    r->label);
	unlink(src); unlink(cs); unlink(ws);
	return rc;
}

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, "def_neg_global: 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,
				    "def_neg_global[%s][%s]: exit=%d want=%d\n",
				    drivers[d].name, rows[i].label,
				    got, rows[i].want);
				fail++;
			}
		}
	}

	/* Asm byte-identity diff, only when wwstage is built. */
	if (access(wdrv, X_OK) == 0) {
		for (int i = 0; i < n; i++) {
			total++;
			if (asm_byte_identical(bin, &rows[i], i) != 0)
				fail++;
		}
	}

	if (fail) {
		fprintf(stderr,
		    "def_neg_global: %d/%d fixtures failed\n", fail, total);
		return 1;
	}
	printf("def_neg_global: %d/%d ok\n", total, total);
	return 0;
}