ww/test/wcc/704_dot_structlit.c

/*
 * 704_dot_structlit — silent zero of nested STRUCTLIT field in
 * cgassign N_DOT-lhs (task #18).
 *
 * Sister bug to #17. #17 fixed the BP-relative sites (N_LET,
 * N_ASSIGN N_IDENT-lhs, N_RETURN) via the cg_structlit_fill_bp /
 * cgstructlitfillbp helper. The N_ASSIGN N_DOT-lhs structlit walks
 * were left inline because their addressing has extra BX-reload
 * concerns (the dst addr is a *struct local or a struct global,
 * loaded into BX, and cgexpr clobbers BX between fields). All four
 * dot-flavors still emitted `cgexpr(field_value); store-AX-sized`
 * for the rhs structlit's fields — and for a struct-typed field
 * whose value is itself an N_STRUCTLIT, that lands only the first
 * qword while the trailing bytes silently stay zero.
 *
 * Affected dot-flavors (each with the same silent-zero shape):
 *   1. single-dot local-base    `o.f = outer { i = inner{...}, ... }`
 *   2. single-dot ptr-base      `p.f = outer { i = inner{...}, ... }`
 *   3. single-dot global-base   `g.f = outer { i = inner{...}, ... }`
 *   4. chained-dot local        `o.x.y = outer { i = inner{...}, ... }`
 *   5. chained-dot ptrroot      `p.x.y = outer { i = inner{...}, ... }`
 *   6. chained-dot global       `g.x.y = outer { i = inner{...}, ... }`
 *
 * Fix (#18): the helper is extended into cg_structlit_fill /
 * cgstructlitfill that takes a destination context (mode, srcoff,
 * name, disp). The old BP-rel wrapper is preserved byte-identically.
 * The four dot-flavor sites in each stage now delegate to the
 * helper, which recurses on nested struct-typed N_STRUCTLIT values
 * at `disp + foff` and reloads BX before each store for the non-BP
 * modes. 995_self_rebuild byte-identity is the load-bearing proof
 * that the no-nested case is byte-identical to the pre-#18 inline
 * walks.
 *
 * Each row pins:
 *   - cstage value correctness (process exit code).
 *   - wwstage value correctness (when ww_ww exists).
 *   - cstage vs wwstage byte-identical .s output (catches drift).
 */
#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; };

static const struct row rows[] = {
	/* single-dot local-base: `h.f = outer { i = inner{...}, ... }`.
	 * Pre-fix: h.f.i.a landed (first qword via cgexpr) but h.f.i.b
	 * silently stayed 0. Want: 7+8+12 = 27. */
	{ "dot_local_lit_nested",
	  "type inner = struct { a: i64, b: i64 };\n"
	  "type outer = struct { i: inner, t: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "fn main() i32 = {\n"
	  "    let h: holder;\n"
	  "    h.f = outer { i = inner { a = 7i64, b = 8i64 }, t = 12i64 };\n"
	  "    return (h.f.i.a + h.f.i.b + h.f.t): i32;\n"
	  "};\n",
	  27 },
	/* single-dot local-base, 3-deep recursion (outer.m.in). Pins
	 * that the disp accumulator threads `foff + middle_foff +
	 * leaf_foff` correctly. Want: 1+2+3+4+9 = 19. */
	{ "dot_local_lit_3deep",
	  "type leaf = struct { a: i64, b: i64 };\n"
	  "type middle = struct { in: leaf, t: i64 };\n"
	  "type outer = struct { m: middle, x: i64 };\n"
	  "type holder = struct { f: outer, pad: i64 };\n"
	  "fn main() i32 = {\n"
	  "    let h: holder;\n"
	  "    h.f = outer {\n"
	  "        m = middle {\n"
	  "            in = leaf { a = 1i64, b = 2i64 },\n"
	  "            t = 3i64\n"
	  "        },\n"
	  "        x = 4i64\n"
	  "    };\n"
	  "    h.pad = 9i64;\n"
	  "    return (h.f.m.in.a + h.f.m.in.b + h.f.m.t + h.f.x + h.pad): i32;\n"
	  "};\n",
	  19 },
	/* single-dot ptr-base (auto-deref): `p.f = outer { i = inner{...}, ... }`.
	 * Exercises DST_PTR_LOCAL mode — helper reloads BX from
	 * srcoff(BP) before zero-fill and before every store. Want:
	 * 9+11+30 = 50. */
	{ "dot_ptr_lit_nested",
	  "type inner = struct { a: i64, b: i64 };\n"
	  "type outer = struct { i: inner, t: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "fn main() i32 = {\n"
	  "    let h: holder;\n"
	  "    let p: *holder = &h;\n"
	  "    p.f = outer { i = inner { a = 9i64, b = 11i64 }, t = 30i64 };\n"
	  "    return (p.f.i.a + p.f.i.b + p.f.t): i32;\n"
	  "};\n",
	  50 },
	/* single-dot global-base: `g.f = outer { i = inner{...}, ... }`.
	 * Exercises DST_GLOBAL mode — helper reloads BX via LEAQ
	 * name(SB) before zero-fill and before every store. `let g: T;`
	 * (no init) per the task #17 module-name-mangle workaround
	 * pattern. Want: 13+17+25 = 55. */
	{ "dot_global_lit_nested",
	  "type inner = struct { a: i64, b: i64 };\n"
	  "type outer = struct { i: inner, t: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "let g: holder;\n"
	  "fn main() i32 = {\n"
	  "    g.f = outer { i = inner { a = 13i64, b = 17i64 }, t = 25i64 };\n"
	  "    return (g.f.i.a + g.f.i.b + g.f.t): i32;\n"
	  "};\n",
	  55 },
	/* chained-dot local (depth-2 lhs): `h.mid.f = outer { i =
	 * inner{...}, ... }`. Exercises the chained-DOT walker with the
	 * non-via_cx (local-through-chain) path — disp = base_disp +
	 * total_off, no BX reload. Want: 4+5+13 = 22. */
	{ "dot_chain_lit_nested",
	  "type inner = struct { a: i64, b: i64 };\n"
	  "type outer = struct { i: inner, t: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "type h2 = struct { mid: holder, pad: i64 };\n"
	  "fn main() i32 = {\n"
	  "    let h: h2;\n"
	  "    h.mid.f = outer { i = inner { a = 4i64, b = 5i64 }, t = 13i64 };\n"
	  "    return (h.mid.f.i.a + h.mid.f.i.b + h.mid.f.t): i32;\n"
	  "};\n",
	  22 },
	/* chained-dot ptrroot (depth-2 lhs through *struct root):
	 * `p.mid.f = outer { i = inner{...}, ... }`. Exercises the
	 * chained-DOT walker with ptrroot=1 — helper mode=1, reloads BX
	 * from rootoff(BP). Want: 6+7+14 = 27. */
	{ "dot_chain_ptr_lit_nested",
	  "type inner = struct { a: i64, b: i64 };\n"
	  "type outer = struct { i: inner, t: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "type h2 = struct { mid: holder, pad: i64 };\n"
	  "fn main() i32 = {\n"
	  "    let h: h2;\n"
	  "    let p: *h2 = &h;\n"
	  "    p.mid.f = outer { i = inner { a = 6i64, b = 7i64 }, t = 14i64 };\n"
	  "    return (p.mid.f.i.a + p.mid.f.i.b + p.mid.f.t): i32;\n"
	  "};\n",
	  27 },
	/* chained-dot global (depth-2 lhs through struct global):
	 * `gg.mid.f = outer { i = inner{...}, ... }`. Exercises the
	 * chained-DOT walker with isglobal=1 — helper mode=2, reloads
	 * BX via LEAQ gg(SB). Want: 10+20+31 = 61. */
	{ "dot_chain_global_lit_nested",
	  "type inner = struct { a: i64, b: i64 };\n"
	  "type outer = struct { i: inner, t: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "type h2 = struct { mid: holder, pad: i64 };\n"
	  "let gg: h2;\n"
	  "fn main() i32 = {\n"
	  "    gg.mid.f = outer { i = inner { a = 10i64, b = 20i64 }, t = 31i64 };\n"
	  "    return (gg.mid.f.i.a + gg.mid.f.i.b + gg.mid.f.t): i32;\n"
	  "};\n",
	  61 },
	/* single-dot ptr-base 3-deep — pins disp threading through the
	 * helper's recursion AND through DST_PTR_LOCAL reloads. Want:
	 * 1+2+3+4 = 10. */
	{ "dot_ptr_lit_3deep",
	  "type leaf = struct { a: i64, b: i64 };\n"
	  "type middle = struct { in: leaf, t: i64 };\n"
	  "type outer = struct { m: middle, x: i64 };\n"
	  "type holder = struct { f: outer };\n"
	  "fn main() i32 = {\n"
	  "    let h: holder;\n"
	  "    let p: *holder = &h;\n"
	  "    p.f = outer {\n"
	  "        m = middle {\n"
	  "            in = leaf { a = 1i64, b = 2i64 },\n"
	  "            t = 3i64\n"
	  "        },\n"
	  "        x = 4i64\n"
	  "    };\n"
	  "    return (p.f.m.in.a + p.f.m.in.b + p.f.m.t + p.f.x): i32;\n"
	  "};\n",
	  10 },
};

/* run_driver — compile r->src via the given driver and exec; return
 * the process exit code. Mirror of 703. */
static int
run_driver(const char *driver, const struct row *r, int i)
{
	char src[64], tmpdir[64], cmd[1024];
	snprintf(src, sizeof src, "/tmp/wcds_%d_%d.ww", getpid(), i);
	snprintf(tmpdir, sizeof tmpdir, "/tmp/wcds_%d_d_%d", getpid(), i);

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

	mkdir(tmpdir, 0755);
	snprintf(cmd, sizeof cmd, "cd %s && %s build %s",
	    tmpdir, driver, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "row[%s]: build via %s failed\n",
		    r->label, driver);
		unlink(src); rmdir(tmpdir);
		return -1;
	}

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

	unlink(src); unlink(outbin); rmdir(tmpdir);
	return got;
}

/* asm_byte_identical — generate .s via cstage's w6c and wwstage's
 * w6c_ww and diff. Mirror of 703. */
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/wcds_asm_%d_%d.ww", getpid(), i);
	snprintf(cs,  sizeof cs,  "/tmp/wcds_asm_%d_%d_c.s", getpid(), i);
	snprintf(ws,  sizeof ws,  "/tmp/wcds_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, "dot_structlit: 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_structlit[%s][%s]: exit=%d want=%d\n",
				    drivers[d].name, rows[i].label,
				    got, rows[i].want);
				fail++;
			}
		}
	}

	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,
		    "dot_structlit: %d/%d fixtures failed\n",
		    fail, total);
		return 1;
	}
	printf("dot_structlit: %d/%d ok\n", total, total);
	return 0;
}