quickjs-libc.c

/*
 * QuickJS C library
 * 
 * Copyright (c) 2017-2021 Fabrice Bellard
 * Copyright (c) 2017-2021 Charlie Gordon
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <inttypes.h>
#include <string.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>
#include <limits.h>
#include <sys/stat.h>
#include <dirent.h>
#if defined(_WIN32)
#include <windows.h>
#include <conio.h>
#include <utime.h>
#else
#if !defined(__wasi__)
#include <dlfcn.h>
#include <termios.h>
#include <sys/wait.h>
#endif
#include <sys/ioctl.h>

#if defined(__APPLE__)
typedef sig_t sighandler_t;
#if !defined(environ)
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#endif
#endif /* __APPLE__ */

#endif

#if !defined(_WIN32) && !defined(__wasi__)
/* enable the os.Worker API. IT relies on POSIX threads */
#define USE_WORKER
#endif

#ifdef USE_WORKER
#include <pthread.h>
#include <stdatomic.h>
#endif

#include "cutils.h"
#include "list.h"
#include "quickjs-libc.h"

/* TODO:
   - add socket calls
*/

typedef struct {
    struct list_head link;
    int fd;
    JSValue rw_func[2];
} JSOSRWHandler;

typedef struct {
    struct list_head link;
    int sig_num;
    JSValue func;
} JSOSSignalHandler;

typedef struct {
    struct list_head link;
    BOOL has_object;
    int64_t timeout;
    JSValue func;
} JSOSTimer;

typedef struct {
    struct list_head link;
    uint8_t *data;
    size_t data_len;
    /* list of SharedArrayBuffers, necessary to free the message */
    uint8_t **sab_tab;
    size_t sab_tab_len;
} JSWorkerMessage;

typedef struct {
    int ref_count;
#ifdef USE_WORKER
    pthread_mutex_t mutex;
#endif
    struct list_head msg_queue; /* list of JSWorkerMessage.link */
    int read_fd;
    int write_fd;
} JSWorkerMessagePipe;

typedef struct {
    struct list_head link;
    JSWorkerMessagePipe *recv_pipe;
    JSValue on_message_func;
} JSWorkerMessageHandler;

typedef struct JSThreadState {
    struct list_head os_rw_handlers; /* list of JSOSRWHandler.link */
    struct list_head os_signal_handlers; /* list JSOSSignalHandler.link */
    struct list_head os_timers; /* list of JSOSTimer.link */
    struct list_head port_list; /* list of JSWorkerMessageHandler.link */
    int eval_script_recurse; /* only used in the main thread */
    /* not used in the main thread */
    JSWorkerMessagePipe *recv_pipe, *send_pipe;
} JSThreadState;

static uint64_t os_pending_signals;
static int (*os_poll_func)(JSContext *ctx);

static void js_std_dbuf_init(JSContext *ctx, DynBuf *s)
{
    dbuf_init2(s, JS_GetRuntime(ctx), (DynBufReallocFunc *)js_realloc_rt);
}

static BOOL my_isdigit(int c)
{
    return (c >= '0' && c <= '9');
}

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;
    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((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:
    dbuf_free(&dbuf);
    return JS_EXCEPTION;
}

uint8_t *js_load_file(JSContext *ctx, size_t *pbuf_len, const char *filename)
{
    FILE *f;
    uint8_t *buf;
    size_t buf_len;
    long lret;
    
    f = fopen(filename, "rb");
    if (!f)
        return NULL;
    if (fseek(f, 0, SEEK_END) < 0)
        goto fail;
    lret = ftell(f);
    if (lret < 0)
        goto fail;
    /* XXX: on Linux, ftell() return LONG_MAX for directories */
    if (lret == LONG_MAX) {
        errno = EISDIR;
        goto fail;
    }
    buf_len = lret;
    if (fseek(f, 0, SEEK_SET) < 0)
        goto fail;
    if (ctx)
        buf = js_malloc(ctx, buf_len + 1);
    else
        buf = malloc(buf_len + 1);
    if (!buf)
        goto fail;
    if (fread(buf, 1, buf_len, f) != buf_len) {
        errno = EIO;
        if (ctx)
            js_free(ctx, buf);
        else
            free(buf);
    fail:
        fclose(f);
        return NULL;
    }
    buf[buf_len] = '\0';
    fclose(f);
    *pbuf_len = buf_len;
    return buf;
}

/* load and evaluate a file */
static JSValue js_loadScript(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    uint8_t *buf;
    const char *filename;
    JSValue ret;
    size_t buf_len;
    
    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        return JS_EXCEPTION;
    buf = js_load_file(ctx, &buf_len, filename);
    if (!buf) {
        JS_ThrowReferenceError(ctx, "could not load '%s'", filename);
        JS_FreeCString(ctx, filename);
        return JS_EXCEPTION;
    }
    ret = JS_Eval(ctx, (char *)buf, buf_len, filename,
                  JS_EVAL_TYPE_GLOBAL);
    js_free(ctx, buf);
    JS_FreeCString(ctx, filename);
    return ret;
}

/* load a file as a UTF-8 encoded string */
static JSValue js_std_loadFile(JSContext *ctx, JSValueConst this_val,
                               int argc, JSValueConst *argv)
{
    uint8_t *buf;
    const char *filename;
    JSValue ret;
    size_t buf_len;
    
    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        return JS_EXCEPTION;
    buf = js_load_file(ctx, &buf_len, filename);
    JS_FreeCString(ctx, filename);
    if (!buf)
        return JS_NULL;
    ret = JS_NewStringLen(ctx, (char *)buf, buf_len);
    js_free(ctx, buf);
    return ret;
}

typedef JSModuleDef *(JSInitModuleFunc)(JSContext *ctx,
                                        const char *module_name);


#if defined(_WIN32) || defined(__wasi__)
static JSModuleDef *js_module_loader_so(JSContext *ctx,
                                        const char *module_name)
{
    JS_ThrowReferenceError(ctx, "shared library modules are not supported yet");
    return NULL;
}
#else
static JSModuleDef *js_module_loader_so(JSContext *ctx,
                                        const char *module_name)
{
    JSModuleDef *m;
    void *hd;
    JSInitModuleFunc *init;
    char *filename;
    
    if (!strchr(module_name, '/')) {
        /* must add a '/' so that the DLL is not searched in the
           system library paths */
        filename = js_malloc(ctx, strlen(module_name) + 2 + 1);
        if (!filename)
            return NULL;
        strcpy(filename, "./");
        strcpy(filename + 2, module_name);
    } else {
        filename = (char *)module_name;
    }
    
    /* C module */
    hd = dlopen(filename, RTLD_NOW | RTLD_LOCAL);
    if (filename != module_name)
        js_free(ctx, filename);
    if (!hd) {
        JS_ThrowReferenceError(ctx, "could not load module filename '%s' as shared library",
                               module_name);
        goto fail;
    }

    init = dlsym(hd, "js_init_module");
    if (!init) {
        JS_ThrowReferenceError(ctx, "could not load module filename '%s': js_init_module not found",
                               module_name);
        goto fail;
    }

    m = init(ctx, module_name);
    if (!m) {
        JS_ThrowReferenceError(ctx, "could not load module filename '%s': initialization error",
                               module_name);
    fail:
        if (hd)
            dlclose(hd);
        return NULL;
    }
    return m;
}
#endif /* !_WIN32 */

int js_module_set_import_meta(JSContext *ctx, JSValueConst func_val,
                              JS_BOOL use_realpath, JS_BOOL is_main)
{
    JSModuleDef *m;
    char buf[PATH_MAX + 16];
    JSValue meta_obj;
    JSAtom module_name_atom;
    const char *module_name;
    
    assert(JS_VALUE_GET_TAG(func_val) == JS_TAG_MODULE);
    m = JS_VALUE_GET_PTR(func_val);

    module_name_atom = JS_GetModuleName(ctx, m);
    module_name = JS_AtomToCString(ctx, module_name_atom);
    JS_FreeAtom(ctx, module_name_atom);
    if (!module_name)
        return -1;
    if (!strchr(module_name, ':')) {
        strcpy(buf, "file://");
#if !defined(_WIN32)
        /* realpath() cannot be used with modules compiled with qjsc
           because the corresponding module source code is not
           necessarily present */
        if (use_realpath) {
            char *res = realpath(module_name, buf + strlen(buf));
            if (!res) {
                JS_ThrowTypeError(ctx, "realpath failure");
                JS_FreeCString(ctx, module_name);
                return -1;
            }
        } else
#endif
        {
            pstrcat(buf, sizeof(buf), module_name);
        }
    } else {
        pstrcpy(buf, sizeof(buf), module_name);
    }
    JS_FreeCString(ctx, module_name);
    
    meta_obj = JS_GetImportMeta(ctx, m);
    if (JS_IsException(meta_obj))
        return -1;
    JS_DefinePropertyValueStr(ctx, meta_obj, "url",
                              JS_NewString(ctx, buf),
                              JS_PROP_C_W_E);
    JS_DefinePropertyValueStr(ctx, meta_obj, "main",
                              JS_NewBool(ctx, is_main),
                              JS_PROP_C_W_E);
    JS_FreeValue(ctx, meta_obj);
    return 0;
}

JSModuleDef *js_module_loader(JSContext *ctx,
                              const char *module_name, void *opaque)
{
    JSModuleDef *m;

    if (has_suffix(module_name, ".so")) {
        m = js_module_loader_so(ctx, module_name);
    } else {
        size_t buf_len;
        uint8_t *buf;
        JSValue func_val;
    
        buf = js_load_file(ctx, &buf_len, module_name);
        if (!buf) {
            JS_ThrowReferenceError(ctx, "could not load module filename '%s'",
                                   module_name);
            return NULL;
        }
        
        /* compile the module */
        func_val = JS_Eval(ctx, (char *)buf, buf_len, module_name,
                           JS_EVAL_TYPE_MODULE | JS_EVAL_FLAG_COMPILE_ONLY);
        js_free(ctx, buf);
        if (JS_IsException(func_val))
            return NULL;
        /* XXX: could propagate the exception */
        js_module_set_import_meta(ctx, func_val, TRUE, FALSE);
        /* the module is already referenced, so we must free it */
        m = JS_VALUE_GET_PTR(func_val);
        JS_FreeValue(ctx, func_val);
    }
    return m;
}

static JSValue js_std_exit(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    int status;
    if (JS_ToInt32(ctx, &status, argv[0]))
        status = -1;
    exit(status);
    return JS_UNDEFINED;
}

static JSValue js_std_getenv(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    const char *name, *str;
    name = JS_ToCString(ctx, argv[0]);
    if (!name)
        return JS_EXCEPTION;
    str = getenv(name);
    JS_FreeCString(ctx, name);
    if (!str)
        return JS_UNDEFINED;
    else
        return JS_NewString(ctx, str);
}

#if defined(_WIN32)
static void setenv(const char *name, const char *value, int overwrite)
{
    char *str;
    size_t name_len, value_len;
    name_len = strlen(name);
    value_len = strlen(value);
    str = malloc(name_len + 1 + value_len + 1);
    memcpy(str, name, name_len);
    str[name_len] = '=';
    memcpy(str + name_len + 1, value, value_len);
    str[name_len + 1 + value_len] = '\0';
    _putenv(str);
    free(str);
}

static void unsetenv(const char *name)
{
    setenv(name, "", TRUE);
}
#endif /* _WIN32 */

static JSValue js_std_setenv(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    const char *name, *value;
    name = JS_ToCString(ctx, argv[0]);
    if (!name)
        return JS_EXCEPTION;
    value = JS_ToCString(ctx, argv[1]);
    if (!value) {
        JS_FreeCString(ctx, name);
        return JS_EXCEPTION;
    }
    setenv(name, value, TRUE);
    JS_FreeCString(ctx, name);
    JS_FreeCString(ctx, value);
    return JS_UNDEFINED;
}

static JSValue js_std_unsetenv(JSContext *ctx, JSValueConst this_val,
                               int argc, JSValueConst *argv)
{
    const char *name;
    name = JS_ToCString(ctx, argv[0]);
    if (!name)
        return JS_EXCEPTION;
    unsetenv(name);
    JS_FreeCString(ctx, name);
    return JS_UNDEFINED;
}

/* return an object containing the list of the available environment
   variables. */
static JSValue js_std_getenviron(JSContext *ctx, JSValueConst this_val,
                                 int argc, JSValueConst *argv)
{
#if !defined(__wasi__)
    char **envp;
    const char *name, *p, *value;
    JSValue obj;
    uint32_t idx;
    size_t name_len;
    JSAtom atom;
    int ret;

    obj = JS_NewObject(ctx);
    if (JS_IsException(obj))
        return JS_EXCEPTION;
    envp = environ;
    for(idx = 0; envp[idx] != NULL; idx++) {
        name = envp[idx];
        p = strchr(name, '=');
        name_len = p - name;
        if (!p)
            continue;
        value = p + 1;
        atom = JS_NewAtomLen(ctx, name, name_len);
        if (atom == JS_ATOM_NULL)
            goto fail;
        ret = JS_DefinePropertyValue(ctx, obj, atom, JS_NewString(ctx, value),
                                     JS_PROP_C_W_E);
        JS_FreeAtom(ctx, atom);
        if (ret < 0)
            goto fail;
    }
    return obj;
 fail:
    JS_FreeValue(ctx, obj);
    return JS_EXCEPTION;
#else
    JSValue obj;
    obj = JS_NewObject(ctx);
    JS_FreeValue(ctx,obj);
    return obj;
#endif
}

static JSValue js_std_gc(JSContext *ctx, JSValueConst this_val,
                         int argc, JSValueConst *argv)
{
    JS_RunGC(JS_GetRuntime(ctx));
    return JS_UNDEFINED;
}

static int interrupt_handler(JSRuntime *rt, void *opaque)
{
    return (os_pending_signals >> SIGINT) & 1;
}

static int get_bool_option(JSContext *ctx, BOOL *pbool,
                           JSValueConst obj,
                           const char *option)
{
    JSValue val;
    val = JS_GetPropertyStr(ctx, obj, option);
    if (JS_IsException(val))
        return -1;
    if (!JS_IsUndefined(val)) {
        *pbool = JS_ToBool(ctx, val);
    }
    JS_FreeValue(ctx, val);
    return 0;
}

static JSValue js_evalScript(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    JSRuntime *rt = JS_GetRuntime(ctx);
    JSThreadState *ts = JS_GetRuntimeOpaque(rt);
    const char *str;
    size_t len;
    JSValue ret;
    JSValueConst options_obj;
    BOOL backtrace_barrier = FALSE;
    int flags;
    
    if (argc >= 2) {
        options_obj = argv[1];
        if (get_bool_option(ctx, &backtrace_barrier, options_obj,
                            "backtrace_barrier"))
            return JS_EXCEPTION;
    }

    str = JS_ToCStringLen(ctx, &len, argv[0]);
    if (!str)
        return JS_EXCEPTION;
    if (!ts->recv_pipe && ++ts->eval_script_recurse == 1) {
        /* install the interrupt handler */
        JS_SetInterruptHandler(JS_GetRuntime(ctx), interrupt_handler, NULL);
    }
    flags = JS_EVAL_TYPE_GLOBAL; 
    if (backtrace_barrier)
        flags |= JS_EVAL_FLAG_BACKTRACE_BARRIER;
    ret = JS_Eval(ctx, str, len, "<evalScript>", flags);
    JS_FreeCString(ctx, str);
    if (!ts->recv_pipe && --ts->eval_script_recurse == 0) {
        /* remove the interrupt handler */
        JS_SetInterruptHandler(JS_GetRuntime(ctx), NULL, NULL);
        os_pending_signals &= ~((uint64_t)1 << SIGINT);
        /* convert the uncatchable "interrupted" error into a normal error
           so that it can be caught by the REPL */
        if (JS_IsException(ret))
            JS_ResetUncatchableError(ctx);
    }
    return ret;
}

static JSClassID js_std_file_class_id;

typedef struct {
    FILE *f;
    BOOL close_in_finalizer;
    BOOL is_popen;
} JSSTDFile;

static void js_std_file_finalizer(JSRuntime *rt, JSValue val)
{
    JSSTDFile *s = JS_GetOpaque(val, js_std_file_class_id);
    if (s) {
#if !defined(__wasi__)
        if (s->f && s->close_in_finalizer) {
            if (s->is_popen)
                pclose(s->f);
            else
                fclose(s->f);
        }
        js_free_rt(rt, s);
#else
        if (s->f && s->close_in_finalizer) {
                fclose(s->f);
        }
        js_free_rt(rt, s);
#endif
    }
}

static ssize_t js_get_errno(ssize_t ret)
{
    if (ret == -1)
        ret = -errno;
    return ret;
}

static JSValue js_std_strerror(JSContext *ctx, JSValueConst this_val,
                                     int argc, JSValueConst *argv)
{
    int err;
    if (JS_ToInt32(ctx, &err, argv[0]))
        return JS_EXCEPTION;
    return JS_NewString(ctx, strerror(err));
}

static JSValue js_std_parseExtJSON(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)
{
    JSValue obj;
    const char *str;
    size_t len;

    str = JS_ToCStringLen(ctx, &len, argv[0]);
    if (!str)
        return JS_EXCEPTION;
    obj = JS_ParseJSON2(ctx, str, len, "<input>", JS_PARSE_JSON_EXT);
    JS_FreeCString(ctx, str);
    return obj;
}

static JSValue js_new_std_file(JSContext *ctx, FILE *f,
                               BOOL close_in_finalizer,
                               BOOL is_popen)
{
    JSSTDFile *s;
    JSValue obj;
    obj = JS_NewObjectClass(ctx, js_std_file_class_id);
    if (JS_IsException(obj))
        return obj;
    s = js_mallocz(ctx, sizeof(*s));
    if (!s) {
        JS_FreeValue(ctx, obj);
        return JS_EXCEPTION;
    }
    s->close_in_finalizer = close_in_finalizer;
    s->is_popen = is_popen;
    s->f = f;
    JS_SetOpaque(obj, s);
    return obj;
}

static void js_set_error_object(JSContext *ctx, JSValue obj, int err)
{
    if (!JS_IsUndefined(obj)) {
        JS_SetPropertyStr(ctx, obj, "errno", JS_NewInt32(ctx, err));
    }
}

static JSValue js_std_open(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    const char *filename, *mode = NULL;
    FILE *f;
    int err;
    
    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        goto fail;
    mode = JS_ToCString(ctx, argv[1]);
    if (!mode)
        goto fail;
    if (mode[strspn(mode, "rwa+b")] != '\0') {
        JS_ThrowTypeError(ctx, "invalid file mode");
        goto fail;
    }

    f = fopen(filename, mode);
    if (!f)
        err = errno;
    else
        err = 0;
    if (argc >= 3)
        js_set_error_object(ctx, argv[2], err);
    JS_FreeCString(ctx, filename);
    JS_FreeCString(ctx, mode);
    if (!f)
        return JS_NULL;
    return js_new_std_file(ctx, f, TRUE, FALSE);
 fail:
    JS_FreeCString(ctx, filename);
    JS_FreeCString(ctx, mode);
    return JS_EXCEPTION;
}

static JSValue js_std_popen(JSContext *ctx, JSValueConst this_val,
                            int argc, JSValueConst *argv)
{
#if !defined(__wasi__)
    const char *filename, *mode = NULL;
    FILE *f;
    int err;
    
    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        goto fail;
    mode = JS_ToCString(ctx, argv[1]);
    if (!mode)
        goto fail;
    if (mode[strspn(mode, "rw")] != '\0') {
        JS_ThrowTypeError(ctx, "invalid file mode");
        goto fail;
    }

    f = popen(filename, mode);
    if (!f)
        err = errno;
    else
        err = 0;
    if (argc >= 3)
        js_set_error_object(ctx, argv[2], err);
    JS_FreeCString(ctx, filename);
    JS_FreeCString(ctx, mode);
    if (!f)
        return JS_NULL;
    return js_new_std_file(ctx, f, TRUE, TRUE);
 fail:
    JS_FreeCString(ctx, filename);
    JS_FreeCString(ctx, mode);
    return JS_EXCEPTION;
#endif
    return JS_EXCEPTION;
}

static JSValue js_std_fdopen(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    const char *mode;
    FILE *f;
    int fd, err;

    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    mode = JS_ToCString(ctx, argv[1]);
    if (!mode)
        goto fail;
    if (mode[strspn(mode, "rwa+")] != '\0') {
        JS_ThrowTypeError(ctx, "invalid file mode");
        goto fail;
    }

    f = fdopen(fd, mode);
    if (!f)
        err = errno;
    else
        err = 0;
    if (argc >= 3)
        js_set_error_object(ctx, argv[2], err);
    JS_FreeCString(ctx, mode);
    if (!f)
        return JS_NULL;
    return js_new_std_file(ctx, f, TRUE, FALSE);
 fail:
    JS_FreeCString(ctx, mode);
    return JS_EXCEPTION;
}

#if !defined(__wasi__)
static JSValue js_std_tmpfile(JSContext *ctx, JSValueConst this_val,
                              int argc, JSValueConst *argv)
{
    FILE *f;
    f = tmpfile();
    if (argc >= 1)
        js_set_error_object(ctx, argv[0], f ? 0 : errno);
    if (!f)