/*
 * 965_f32stamp_run — runtime + byte-id regression net for #104 fold-2: an
 * UN-suffixed float literal in an f32 context (`let x: f32 = 1.0`, `return
 * 1.0` from an f32 fn) must be stamped f32 by the checker so fold-1's cgen
 * narrow (CVTSD2SS at the literal materialise site) fires. Without the stamp
 * the literal stays ty_untyped_float, materialises as a 64-bit double, and
 * the f32 consumer reads the LOW 4 BYTES of that double — 0x00000000 == 0.0f
 * for clean values (`1.0` -> 0.0f, so `x: f64 != 1.0` trips). fold-1 (964)
 * only covered SUFFIXED literals (`1.0f32`); the un-suffixed common case was
 * its documented hole, closed here.
 *
 * Both checkers stamp the literal: cstage cmd/wcc/check.c coerce_floatlit (at
 * clet + cstmt N_RETURN), wwstage selfhost/cmd/wcc/check.ww coercefloatlit (in
 * resolvewalk's post-order N_LET / N_RETURN handler — placed AFTER the child
 * re-walk so the post-order exprtype re-stamp doesn't undo it). Both stages
 * emit byte-identical asm, so the 990-997 byte-id gates can NEVER catch a
 * reintroduction — only an executed-and-checked runtime probe can.
 *
 * SCOPE (#104 fold-2): the stamp fires at let-init and return ONLY. binop
 * (`1.0 + x_f32`), unary minus (`-1.0`), assign, call-arg, and struct-field
 * are DEFERRED to #120 — the wwstage cgen's exprfloatkind (cgenutil.ww)
 * hardcodes a float literal to f64 and picks f32 off the operands, not the
 * node stamp, so a stamped literal in those positions does not narrow in
 * wwstage (cs would emit ADDSS, ww ADDSD — a byte-id break). This probe
 * therefore uses bare let-init / return literals exclusively.
 *
 * Each row carries BOTH dimensions (like 955 / 964):
 *   (a) cstage `ww build` + run, asserting the exit code.
 *   (b) w6c vs w6c_ww `.s` cmp — FAILS if the stages diverge (rule-10).
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.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_exit; };

static const struct row rows[] = {
	/* The hole 964 leaves: a bare (UN-suffixed) f32-context literal. On
	 * the bug `let x: f32 = 1.0` stores the low 4 bytes of double 1.0
	 * (== 0x00000000 == 0.0f), so x:f64 == 0.0 != 1.0 -> 1. */
	{ "let_one",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let x: f32 = 1.0;\n"
	  "	if (x: f64 != 1.0) { return 1; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	/* a bare decimal literal truncated through i32: 8.0 -> 8. On the bug
	 * the f32 slot holds 0.0f -> 0. */
	{ "let_decimal",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let y: f32 = 8.0;\n"
	  "	return y: i32;\n"
	  "};\n", 8 },
	/* a fractional value (exactly representable): 0.5. Bug -> 0.0f, so
	 * p:f64 == 0.0 != 0.5 -> 1. */
	{ "let_frac",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let p: f32 = 0.5;\n"
	  "	if (p: f64 != 0.5) { return 1; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	/* return context: an f32 fn returning a bare literal, truncated to
	 * i32 at the call site. 2.0 -> 2. On the bug the X0 single is the
	 * low half of double 2.0 (== 0.0f) -> 0. */
	{ "return_bare",
	  "package main;\n"
	  "fn g() f32 = { return 2.0; };\n"
	  "export fn main() i32 = {\n"
	  "	return g(): i32;\n"
	  "};\n", 2 },
	/* return feeding a let, both un-suffixed: the literal narrows in the
	 * fn return, the let-init binds the (already-f32) call value. 4.0 ->
	 * 4. */
	{ "return_then_let",
	  "package main;\n"
	  "fn h() f32 = { return 4.0; };\n"
	  "export fn main() i32 = {\n"
	  "	let r: f32 = h();\n"
	  "	if (r: f64 != 4.0) { return 1; };\n"
	  "	return r: i32;\n"
	  "};\n", 4 },
	{ NULL, NULL, 0 }
};

static int
slurp_eq(const char *a, const char *b)
{
	FILE *fa = fopen(a, "rb");
	FILE *fb = fopen(b, "rb");
	if (!fa || !fb) { if (fa) fclose(fa); if (fb) fclose(fb); return -1; }
	int rc = 0;
	for (;;) {
		int ca = fgetc(fa);
		int cb = fgetc(fb);
		if (ca != cb) { rc = -1; break; }
		if (ca == EOF) break;
	}
	fclose(fa); fclose(fb);
	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 w6c[1100], w6c_ww[1100];
	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, "f32stamp: w6c_ww missing — cannot run the "
		    "cs==ww byte-id gate (the whole point of this test)\n");
		return 1;
	}

	int n = 0, fail = 0;
	for (int i = 0; rows[i].src; i++, n++) {
		char src[64];
		snprintf(src, sizeof src, "/tmp/wwf32s_%d_%d.ww", getpid(), i);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		/* (a) cstage build + run. */
		char tmpdir[64];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwf32s_%d_d_%d",
		    getpid(), i);
		mkdir(tmpdir, 0755);

		char cmd[2048];
		snprintf(cmd, sizeof cmd, "cd %s && %s/ww build %s",
		    tmpdir, bin, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: cstage build failed\n",
			    rows[i].label);
			fail++;
			unlink(src); rmdir(tmpdir);
			continue;
		}

		char outbin[128];
		const char *base = strrchr(src, '/');
		base = base ? base + 1 : src;
		snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
		char *dot = strrchr(outbin, '.');
		if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';

		int got = runwait(outbin);
		if (got != rows[i].want_exit) {
			fprintf(stderr, "row[%s]: cstage exit %d, want %d\n",
			    rows[i].label, got, rows[i].want_exit);
			fail++;
		}
		unlink(outbin); rmdir(tmpdir);

		/* (b) cs==ww byte-id gate: emit .s from both stages, cmp. */
		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwf32s_%d_%d_cs.s",
		    getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwf32s_%d_%d_ww.s",
		    getpid(), i);

		snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null",
		    w6c, cs_s, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: w6c failed\n", rows[i].label);
			fail++; unlink(src); continue;
		}
		snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null",
		    w6c_ww, ws_s, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: w6c_ww failed\n",
			    rows[i].label);
			fail++; unlink(src); unlink(cs_s); continue;
		}
		if (slurp_eq(cs_s, ws_s) != 0) {
			fprintf(stderr,
			    "row[%s]: cstage/wwstage .s DIFFER (rule-10 "
			    "byte-id violation)\n", rows[i].label);
			fail++;
		}
		unlink(src); unlink(cs_s); unlink(ws_s);
	}

	if (fail) {
		fprintf(stderr, "%d/%d f32 un-suffixed stamp tests failed\n",
		    fail, n);
		return 1;
	}
	printf("f32stamp: %d/%d ok (cstage run + cs==ww byte-id)\n", n, n);
	return 0;
}