buffer.c

// Copyright 2012 Rui Ueyama <rui314@gmail.com>
// This program is free software licensed under the MIT license.

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include "8cc.h"

#define INIT_SIZE 8

Buffer *make_buffer(void) {
    Buffer *r = malloc(sizeof(Buffer));
    r->body = malloc(INIT_SIZE);
    r->nalloc = INIT_SIZE;
    r->len = 0;
    return r;
}

static void realloc_body(Buffer *b) {
    int newsize = b->nalloc * 2;
    char *body = malloc(newsize);
    memcpy(body, b->body, b->len);
    b->body = body;
    b->nalloc = newsize;
}

char *buf_body(Buffer *b) {
    return b->body;
}

int buf_len(Buffer *b) {
    return b->len;
}

void buf_write(Buffer *b, char c) {
    if (b->nalloc == (b->len + 1))
        realloc_body(b);
    b->body[b->len++] = c;
}

void buf_printf(Buffer *b, char *fmt, ...) {
    va_list args;
    for (;;) {
        int avail = b->nalloc - b->len;
        va_start(args, fmt);
        int written = vsnprintf(b->body + b->len, avail, fmt, args);
        va_end(args);
        if (avail <= written) {
            realloc_body(b);
            continue;
        }
        b->len += written;
        return;
    }
}

char *vformat(char *fmt, va_list ap) {
    Buffer *b = make_buffer();
    va_list aq;
    for (;;) {
        int avail = b->nalloc - b->len;
        va_copy(aq, ap);
        int written = vsnprintf(b->body + b->len, avail, fmt, aq);
        va_end(aq);
        if (avail <= written) {
            realloc_body(b);
            continue;
        }
        b->len += written;
        return buf_body(b);
    }
}

char *format(char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    char *r = vformat(fmt, ap);
    va_end(ap);
    return r;
}

char *quote_cstring(char *p) {
    Buffer *b = make_buffer();
    while (*p) {
        if (*p == '\"' || *p == '\\')
            buf_printf(b, "\\%c", *p);
        else if (*p == '\n')
            buf_printf(b, "\\n");
        else
            buf_printf(b, "%c", *p);
        p++;
    }
    return buf_body(b);
}

char *quote_char(char c) {
    if (c == '\\') return "\\\\";
    if (c == '\'') return "\\'";
    return format("%c", c);
}