/*
 * 800_ffi — verify the @symbol("X") attribute redirects CALLs at
 * the codegen layer. The ww source declares a body-less fn with an
 * external symbol name, calls it; the emitted .s must reference the
 * external name, not the ww-side ident.
 *
 * Also smoke-tests building lib/c/libc/libc.ww (parse + check + cgen
 * succeed; nothing to run).
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static char *
run6c(const char *bin, const char *src)
{
	char path[64];
	snprintf(path, sizeof path, "/tmp/wwffi_%d.ww", getpid());
	FILE *f = fopen(path, "wb");
	fputs(src, f);
	fclose(f);

	char cmd[512];
	snprintf(cmd, sizeof cmd, "%s/w6c %s 2>&1", bin, path);
	FILE *p = popen(cmd, "r");
	size_t cap = 4096, n = 0;
	char *buf = malloc(cap);
	int c;
	while ((c = fgetc(p)) != EOF) {
		if (n + 1 >= cap) { cap *= 2; buf = realloc(buf, cap); }
		buf[n++] = (char)c;
	}
	buf[n] = '\0';
	pclose(p);
	unlink(path);
	return buf;
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";

	int fail = 0;

	/* @symbol redirects ident name to symbol name */
	{
		char *out = run6c(bin,
		    "@symbol(\"cout\") fn writeit(b: *u8, n: u64) i64;\n"
		    "fn main() i32 = { writeit(nil, 0); return 0; };");
		if (strstr(out, "CALL\tcout(SB)") == NULL) {
			fprintf(stderr, "ffi: missing CALL cout(SB) in:\n%s\n", out);
			fail++;
		}
		if (strstr(out, "CALL\twriteit(SB)") != NULL) {
			fprintf(stderr, "ffi: should not call by ident name:\n%s\n", out);
			fail++;
		}
		free(out);
	}

	/* lib/c/libc parses + cgens (no defined fns means no TEXT directives) */
	{
		char path[256];
		snprintf(path, sizeof path, "%s/../../lib/c/libc/libc.ww", bin);
		char cmd[512];
		snprintf(cmd, sizeof cmd, "%s/w6c %s > /dev/null 2>&1", bin, path);
		int rc = system(cmd);
		if (rc != 0) {
			fprintf(stderr, "ffi: w6c failed on libc.ww (rc=%d)\n", rc);
			fail++;
		}
	}

	if (fail) return 1;
	puts("ffi: ok");
	return 0;
}