static JSValue js_printf_internal()

in src/couch_quickjs/quickjs/quickjs-libc.c [164:379]

• 193 lines of code
• 62 McCabe index (conditional complexity)

static JSValue js_printf_internal(JSContext *ctx,
                                  int argc, JSValueConst *argv, FILE *fp)
{
    char fmtbuf[32];
    uint8_t cbuf[UTF8_CHAR_LEN_MAX+1];
    JSValue res;
    DynBuf dbuf;
    const char *fmt_str = NULL;
    const uint8_t *fmt, *fmt_end;
    const uint8_t *p;
    char *q;
    int i, c, len, mod;
    size_t fmt_len;
    int32_t int32_arg;
    int64_t int64_arg;
    double double_arg;
    const char *string_arg;
    /* Use indirect call to dbuf_printf to prevent gcc warning */
    int (*dbuf_printf_fun)(DynBuf *s, const char *fmt, ...) = (void*)dbuf_printf;

    js_std_dbuf_init(ctx, &dbuf);

    if (argc > 0) {
        fmt_str = JS_ToCStringLen(ctx, &fmt_len, argv[0]);
        if (!fmt_str)
            goto fail;

        i = 1;
        fmt = (const uint8_t *)fmt_str;
        fmt_end = fmt + fmt_len;
        while (fmt < fmt_end) {
            for (p = fmt; fmt < fmt_end && *fmt != '%'; fmt++)
                continue;
            dbuf_put(&dbuf, p, fmt - p);
            if (fmt >= fmt_end)
                break;
            q = fmtbuf;
            *q++ = *fmt++;  /* copy '%' */

            /* flags */
            for(;;) {
                c = *fmt;
                if (c == '0' || c == '#' || c == '+' || c == '-' || c == ' ' ||
                    c == '\'') {
                    if (q >= fmtbuf + sizeof(fmtbuf) - 1)
                        goto invalid;
                    *q++ = c;
                    fmt++;
                } else {
                    break;
                }
            }
            /* width */
            if (*fmt == '*') {
                if (i >= argc)
                    goto missing;
                if (JS_ToInt32(ctx, &int32_arg, argv[i++]))
                    goto fail;
                q += snprintf(q, fmtbuf + sizeof(fmtbuf) - q, "%d", int32_arg);
                fmt++;
            } else {
                while (my_isdigit(*fmt)) {
                    if (q >= fmtbuf + sizeof(fmtbuf) - 1)
                        goto invalid;
                    *q++ = *fmt++;
                }
            }
            if (*fmt == '.') {
                if (q >= fmtbuf + sizeof(fmtbuf) - 1)
                    goto invalid;
                *q++ = *fmt++;
                if (*fmt == '*') {
                    if (i >= argc)
                        goto missing;
                    if (JS_ToInt32(ctx, &int32_arg, argv[i++]))
                        goto fail;
                    q += snprintf(q, fmtbuf + sizeof(fmtbuf) - q, "%d", int32_arg);
                    fmt++;
                } else {
                    while (my_isdigit(*fmt)) {
                        if (q >= fmtbuf + sizeof(fmtbuf) - 1)
                            goto invalid;
                        *q++ = *fmt++;
                    }
                }
            }

            /* we only support the "l" modifier for 64 bit numbers */
            mod = ' ';
            if (*fmt == 'l') {
                mod = *fmt++;
            }

            /* type */
            c = *fmt++;
            if (q >= fmtbuf + sizeof(fmtbuf) - 1)
                goto invalid;
            *q++ = c;
            *q = '\0';

            switch (c) {
            case 'c':
                if (i >= argc)
                    goto missing;
                if (JS_IsString(argv[i])) {
                    string_arg = JS_ToCString(ctx, argv[i++]);
                    if (!string_arg)
                        goto fail;
                    int32_arg = unicode_from_utf8((const uint8_t *)string_arg, UTF8_CHAR_LEN_MAX, &p);
                    JS_FreeCString(ctx, string_arg);
                } else {
                    if (JS_ToInt32(ctx, &int32_arg, argv[i++]))
                        goto fail;
                }
                /* handle utf-8 encoding explicitly */
                if ((unsigned)int32_arg > 0x10FFFF)
                    int32_arg = 0xFFFD;
                /* ignore conversion flags, width and precision */
                len = unicode_to_utf8(cbuf, int32_arg);
                dbuf_put(&dbuf, cbuf, len);
                break;

            case 'd':
            case 'i':
            case 'o':
            case 'u':
            case 'x':
            case 'X':
                if (i >= argc)
                    goto missing;
                if (JS_ToInt64Ext(ctx, &int64_arg, argv[i++]))
                    goto fail;
                if (mod == 'l') {
                    /* 64 bit number */
#if defined(_WIN32)
                    if (q >= fmtbuf + sizeof(fmtbuf) - 3)
                        goto invalid;
                    q[2] = q[-1];
                    q[-1] = 'I';
                    q[0] = '6';
                    q[1] = '4';
                    q[3] = '\0';
                    dbuf_printf_fun(&dbuf, fmtbuf, (int64_t)int64_arg);
#else
                    if (q >= fmtbuf + sizeof(fmtbuf) - 2)
                        goto invalid;
                    q[1] = q[-1];
                    q[-1] = q[0] = 'l';
                    q[2] = '\0';
                    dbuf_printf_fun(&dbuf, fmtbuf, (long long)int64_arg);
#endif
                } else {
                    dbuf_printf_fun(&dbuf, fmtbuf, (int)int64_arg);
                }
                break;

            case 's':
                if (i >= argc)
                    goto missing;
                /* XXX: handle strings containing null characters */
                string_arg = JS_ToCString(ctx, argv[i++]);
                if (!string_arg)
                    goto fail;
                dbuf_printf_fun(&dbuf, fmtbuf, string_arg);
                JS_FreeCString(ctx, string_arg);
                break;

            case 'e':
            case 'f':
            case 'g':
            case 'a':
            case 'E':
            case 'F':
            case 'G':
            case 'A':
                if (i >= argc)
                    goto missing;
                if (JS_ToFloat64(ctx, &double_arg, argv[i++]))
                    goto fail;
                dbuf_printf_fun(&dbuf, fmtbuf, double_arg);
                break;

            case '%':
                dbuf_putc(&dbuf, '%');
                break;

            default:
                /* XXX: should support an extension mechanism */
            invalid:
                JS_ThrowTypeError(ctx, "invalid conversion specifier in format string");
                goto fail;
            missing:
                JS_ThrowReferenceError(ctx, "missing argument for conversion specifier");
                goto fail;
            }
        }
        JS_FreeCString(ctx, fmt_str);
    }
    if (dbuf.error) {
        res = JS_ThrowOutOfMemory(ctx);
    } else {
        if (fp) {
            len = fwrite(dbuf.buf, 1, dbuf.size, fp);
            res = JS_NewInt32(ctx, len);
        } else {
            res = JS_NewStringLen(ctx, (char *)dbuf.buf, dbuf.size);
        }
    }
    dbuf_free(&dbuf);
    return res;

fail:
    JS_FreeCString(ctx, fmt_str);
    dbuf_free(&dbuf);
    return JS_EXCEPTION;
}