ww/test/wcc/989_tupfieldsize_run.c

/*
 * 989_tupfieldsize_run — F7-c4 (#43): a for-range destructure over an
 * array of tuples must stride by the tuple's TRUE size; a slice/str/nested
 * tuple FIELD carries its full width, not the 8B scalar default.
 *
 * THE BUG (cat-A silent miscompile, gate-blind): paramfieldsize
 * (selfhost/cmd/wcc/cgenstmt.ww) — the structural sizer the for-range
 * destructure uses to compute the tuple stride and each field's offset —
 * had no N_TSLICE / N_TTUPLE arm, so a `[]T` tuple-field sized 8 (the
 * default) instead of its 24B header. The #270-1c array-literal guard
 * blocks only the literal CONSTRUCTION; the for-range DESTRUCTURE-READ
 * path is unguarded (ken's oracle refuted "unreachable"). For
 * `[2]([]u8, i64)` the wwstage strode the tuple at 16 / read field-2 at
 * offset 8, vs cstage's 32 / 24 — a cs≠ww divergence (the cat-A
 * signature). cstage's tp->type->size (cmd/w6c/cgen.c N_FORRANGE) reads
 * the true width. THE FIX: add the N_TSLICE arm (tyslicesize() = 24, the
 * slice-header SSoT, rule-13) and the N_TTUPLE arm (sum of 8B-floored
 * element slots, recursive), aligning wwstage UP.
 *
 * #40 (#263, now CLOSED both stages — fused): F7-c4 fixed only the STRIDE,
 * so the slice-field row was pinned cs==ww (MATCH-ONLY) at 40, NOT the
 * arithmetic-expected 45 — because the destructure LOAD-into-binding copied
 * only the PTR word of the 24B slice binding, dropping .len/.cap (both stages
 * identically; nobody had re-measured the ww absolute after F7-c4). The fused
 * #40 fix (cgen.c N_FORRANGE destructure + cgenstmt.ww cgforrange twin: copy
 * the binding's FULL extent for an aggregate sz>8 binding, same word-run +
 * sized-tail idiom as the non-destructure copy) lands all three header words.
 * The rows now pin the ABSOLUTE value cs==ww across all three words — the
 * recurring dropped word in this 24B-aggregate-destructure family is the CAP
 * (cf #29 chained-dot, #43 sizer), so the cap row reads b.cap with cap!=len
 * (sliced) to teeth it; a ptr+len-only set would pass green while cap stayed
 * stale (exactly how #40 hid).
 *
 * Tuples are built by whole-tuple element store (`xs[i] = (..)`).
 *
 * Rows (cstage `ww` + wwstage `ww_ww`; rule-10; all pin the absolute value):
 *   row               | reads                              | exit (cs==ww)
 *   ------------------+------------------------------------+--------------
 *   len_read          | len(b)+n over [2]([]u8,i64)         | 45  (2+10+3+30)
 *   cap_read          | b.cap+n, sliced caps 4/5 (cap!=len) | 49  (4+10+5+30)
 *   ptr_read          | b[0]+ (byte through ptr)            | 217 (97+120)
 *   scalar_tuple_ctl  | for(.. [2](i64,i64))                | 48  (control)
 * Pre-fix (single-word copy): len_read=40, cap_read=40 (len/cap words both 0),
 * ptr_read=217 (word0 always copied — coverage, no teeth); cs==ww==wrong (the
 * #263 both-wrong-identical residual the fused fix retires).
 */
#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_exit;	/* >= 0: also pin the absolute value; -1: cs==ww only */
};

static const struct row rows[] = {
	/* (1) len_read (#40 teeth, word 1): the slice binding's .len must be
	 * copied. Pre-fix the single-word copy dropped it → len(b)=0 → 40. */
	{ "len_read",
	  "package main;\n"
	  "export fn main() int = {\n"
	  "	let b0: []u8 = ['a', 'b'];\n"
	  "	let b1: []u8 = ['x', 'y', 'z'];\n"
	  "	let xs: [2]([]u8, i64);\n"
	  "	xs[0] = (b0, 10);\n"
	  "	xs[1] = (b1, 30);\n"
	  "	let sum: i64 = 0;\n"
	  "	for (let (b, n) .. xs) {\n"
	  "		sum = sum + len(b): i64 + n;\n"
	  "	};\n"
	  "	return sum: int;\n"
	  "};\n",
	  45 },

	/* (2) cap_read (#40 teeth, word 2 — THE recurring dropped word): caps
	 * 4/5 are SLICED so cap != len (2/3); pre-fix b.cap=0 → 40. */
	{ "cap_read",
	  "package main;\n"
	  "export fn main() int = {\n"
	  "	let base0: []u8 = ['a', 'b', 'c', 'd'];\n"
	  "	let base1: []u8 = ['p', 'q', 'r', 's', 't'];\n"
	  "	let xs: [2]([]u8, i64);\n"
	  "	xs[0] = (base0[0:2], 10);\n"
	  "	xs[1] = (base1[0:3], 30);\n"
	  "	let sum: i64 = 0;\n"
	  "	for (let (b, n) .. xs) {\n"
	  "		sum = sum + b.cap: i64 + n;\n"
	  "	};\n"
	  "	return sum: int;\n"
	  "};\n",
	  49 },

	/* (3) ptr_read (word 0 — coverage; word0 was always copied, no teeth):
	 * a byte read through the binding's .ptr. b0[0]='a'=97, b1[0]='x'=120. */
	{ "ptr_read",
	  "package main;\n"
	  "export fn main() int = {\n"
	  "	let b0: []u8 = ['a', 'b'];\n"
	  "	let b1: []u8 = ['x', 'y', 'z'];\n"
	  "	let xs: [2]([]u8, i64);\n"
	  "	xs[0] = (b0, 10);\n"
	  "	xs[1] = (b1, 30);\n"
	  "	let sum: i64 = 0;\n"
	  "	for (let (b, n) .. xs) { sum = sum + b[0]: i64; };\n"
	  "	return sum: int;\n"
	  "};\n",
	  217 },

	/* (4) control — scalar-only tuple (no aggregate field): paramfieldsize
	 * already handled it; the sz>8 arm must not touch it. 3+10+5+30 == 48. */
	{ "scalar_tuple_ctl",
	  "package main;\n"
	  "export fn main() int = {\n"
	  "	let xs: [2](i64, i64);\n"
	  "	xs[0] = (3, 10); xs[1] = (5, 30);\n"
	  "	let sum: i64 = 0;\n"
	  "	for (let (a, b) .. xs) { sum = sum + a + b; };\n"
	  "	return sum: int;\n"
	  "};\n",
	  48 },
};

/* run_build — build+run `src` via `driver`; returns the binary's exit
 * code, or -1 on a build failure. */
static int
run_build(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/tupfs_%d_d_%d", getpid(), i);
	mkdir(tmpdir, 0755);
	snprintf(src, sizeof src, "%s/tupfs_%d_%d.ww", tmpdir, getpid(), i);
	snprintf(outbin, sizeof outbin, "%s/tupfs_%d_%d", tmpdir, getpid(), i);
	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);

	FILE *f = fopen(src, "wb");
	if (!f) { runwait(rmcmd); return -2; }
	fputs(r->src, f);
	fclose(f);

	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null",
	    driver, outbin, src);
	int brc = runwait(cmd);

	int got = -1;
	if (brc == 0) got = runwait(outbin);

	runwait(rmcmd);
	return brc == 0 ? got : -1;
}

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], wdrv[1024];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
	int have_ww = (access(wdrv, X_OK) == 0);

	int n = (int)(sizeof rows / sizeof rows[0]);
	int total = 0, fail = 0;

	for (int i = 0; i < n; i++) {
		total++;
		int gc = run_build(cdrv, &rows[i], i);
		/* cstage must build+run */
		if (gc < 0) {
			fprintf(stderr, "tupfieldsize_run[cstage][%s]: build/run "
			    "failed (got %d)\n", rows[i].label, gc);
			fail++;
			continue;
		}
		if (rows[i].want_exit >= 0 && gc != rows[i].want_exit) {
			fprintf(stderr, "tupfieldsize_run[cstage][%s]: exit=%d "
			    "want=%d\n", rows[i].label, gc, rows[i].want_exit);
			fail++;
		}
		if (!have_ww) {
			fprintf(stderr, "tupfieldsize_run: skip wwstage (no %s)\n",
			    wdrv);
			continue;
		}
		int gw = run_build(wdrv, &rows[i], i);
		/* rule-10: the cat-A invariant is cs == ww */
		if (gw != gc) {
			fprintf(stderr, "tupfieldsize_run[%s]: cs=%d != ww=%d "
			    "(stride/offset divergence — #43)\n",
			    rows[i].label, gc, gw);
			fail++;
		}
		if (rows[i].want_exit >= 0 && gw != rows[i].want_exit) {
			fprintf(stderr, "tupfieldsize_run[wwstage][%s]: exit=%d "
			    "want=%d\n", rows[i].label, gw, rows[i].want_exit);
			fail++;
		}
	}

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