/* mkrom.c -- build the ROM, off the node, as a bitstream is built.
 *
 *     mkrom OUT.c OUT.sym MAP.f18 SOURCE.f18...
 *
 * docs/v4.0.0/MACHINE.md section 2.  The ROM is F18 code, written in the
 * text assembler's notation (include/v4/text.h) in capsules/v4/rom, and this
 * is the only thing built off the node.  It assembles MAP.f18 (the memory
 * map's constants, from tools/mkmap.c) and then each SOURCE in the order
 * given, at the ROM's base address, and writes:
 *   OUT.c    the ROM: const v4_cell v4_rom_<width>[] and its length
 *   OUT.sym  every word of it, "NAME ADDRESS" a line, for the tests
 *
 * This tool is built with a node whose RAM reaches over the ROM's range
 * (V4_NODE_WORDS = the host's RAM plus its ROM range, V4_ROM_WORDS = 0), so
 * the assembler can lay the ROM down where it will run; ROM_ORIGIN is the
 * host's RAM size, which is where the ROM starts on the machine.  The
 * assembler's branch placement depends only on the top of the address space,
 * which is the same either way.
 */
#include "v4/text.h"
#include <stdio.h>
#include <stdlib.h>

#ifndef ROM_ORIGIN
#error "ROM_ORIGIN must be the host node's RAM size"
#endif
#ifndef ROM_RANGE
#error "ROM_RANGE must be the host node's ROM range, in words"
#endif

static v4_node n;
static v4_text tx;

static void die(const char *what, const char *detail)
{
    fprintf(stderr, "mkrom: %s%s%s\n", what, detail ? ": " : "", detail ? detail : "");
    exit(1);
}

/* a cell as a C constant of the cell's type, with no implementation-defined conversion */
static void put_cell(FILE *f, v4_cell v)
{
#if V4_CELL_BITS == 64
    if (v == (v4_cell)((v4_ucell)1 << 63)) fprintf(f, "(-9223372036854775807LL - 1)");
    else fprintf(f, "%lldLL", (long long)v);
#else
    if (v == (v4_cell)((v4_ucell)1 << 31)) fprintf(f, "(-2147483647L - 1)");
    else fprintf(f, "%ldL", (long)v);
#endif
}

int main(int argc, char **argv)
{
    FILE *out;
    v4_cell here, a;
    int i;
    unsigned s;

    if (argc < 5) die("usage: mkrom OUT.c OUT.sym MAP.f18 SOURCE.f18...", NULL);
    if ((v4_ucell)V4_NODE_WORDS != (v4_ucell)ROM_ORIGIN + (v4_ucell)ROM_RANGE)
        die("built with the wrong node size: RAM must reach over the ROM's range", NULL);

    v4_node_reset(&n);
    v4_text_begin(&tx, &n, ROM_ORIGIN);
    for (i = 3; i < argc; i++)
        if (!v4_text_assemble_file(&tx, argv[i])) die("does not assemble", v4_text_error(&tx));
    if (!v4_text_finish(&tx)) die("not everything is defined", v4_text_error(&tx));
    here = v4_text_here(&tx);
    if (here - (v4_cell)ROM_ORIGIN > (v4_cell)ROM_RANGE) die("the ROM is larger than its range", NULL);

    out = fopen(argv[1], "w");
    if (!out) die("cannot write", argv[1]);
    fprintf(out, "/* Generated by v4/tools/mkrom.c from capsules/v4/rom -- do not edit. */\n#include \"v4/cell.h\"\n\n");
    fprintf(out, "const v4_cell v4_rom_%d[] = {\n", V4_CELL_BITS);
    for (a = ROM_ORIGIN; a < here; a++) {
        fprintf(out, "    ");
        put_cell(out, n.mem[a]);
        fprintf(out, ",\n");
    }
    if (here == ROM_ORIGIN) fprintf(out, "    0\n");
    fprintf(out, "};\nconst unsigned v4_rom_%d_words = %ldu;\n", V4_CELL_BITS, (long)(here - (v4_cell)ROM_ORIGIN));
    if (fclose(out) != 0) die("cannot write", argv[1]);

    out = fopen(argv[2], "w");
    if (!out) die("cannot write", argv[2]);
    for (s = 0; s < tx.nsym; s++)
        if (tx.sym[s].kind == 1) fprintf(out, "%s %ld\n", tx.pool + tx.sym[s].name, (long)tx.sym[s].value);
    if (fclose(out) != 0) die("cannot write", argv[2]);

    fprintf(stderr, "mkrom: a ROM of %ld words, %d-bit cells -> %s\n", (long)(here - (v4_cell)ROM_ORIGIN), V4_CELL_BITS, argv[1]);
    return 0;
}