bootstrap/rtl/writer.c


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/*
 * Minimal bootstrap RTL (runtime library) - Writer (output) functions.
 *
 * Copyright © 2025 Samuel Lidén Borell <samuel@kodafritt.se>
 *
 * SPDX-License-Identifier: EUPL-1.2+ OR LGPL-2.1-or-later
 */
#include <assert.h>
#include "rtl.h"
#include "internal.h"

struct Writer {
    FILE *file;
    /**
     * Filename for deleting file on error (TODO) and for error messages.
     * Note that the filename should NOT be exposed to the application.
     */
    const char *filename;
};

static struct Writer *Writer__from_file(FILE *f, const char *filename)
{
    struct Writer *wr = malloc(sizeof(struct Writer));
    OOM_CHECK(wr);
    wr->file = f;
    wr->filename = filename;
    return wr;
}

struct Writer *Writer__from_filename(const char *filename)
{
    FILE *f;
    f = fopen(filename, "wb");
    if (!f) {
        perror(filename);
        exit(EXIT_FAILURE);
    }
    return Writer__from_file(f, filename);
}

void Writer_write_str(
        struct Writer *wr,
        const struct String *text)
{
    SlulInt len;
    const unsigned char *data = SLUL__decode_string(text, &len);
    if (fwrite(data, len, 1, wr->file) != 1) {
        perror(wr->filename);
        exit(EXIT_FAILURE);
    }
}