load.c

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/*
 * load methods from eval.c
 */

#include "ruby/ruby.h"
#include "ruby/util.h"
#include "dln.h"
#include "eval_intern.h"

VALUE ruby_dln_librefs;

#define IS_RBEXT(e) (strcmp(e, ".rb") == 0)
#define IS_SOEXT(e) (strcmp(e, ".so") == 0 || strcmp(e, ".o") == 0)
#ifdef DLEXT2
#define IS_DLEXT(e) (strcmp(e, DLEXT) == 0 || strcmp(e, DLEXT2) == 0)
#else
#define IS_DLEXT(e) (strcmp(e, DLEXT) == 0)
#endif


static const char *const loadable_ext[] = {
    ".rb", DLEXT,
#ifdef DLEXT2
    DLEXT2,
#endif
    0
};

VALUE
rb_get_load_path(void)
{
    VALUE load_path = GET_VM()->load_path;
    return load_path;
}

VALUE
rb_get_expanded_load_path(void)
{
    VALUE load_path = rb_get_load_path();
    VALUE ary;
    long i;

    for (i = 0; i < RARRAY_LEN(load_path); ++i) {
        VALUE str = rb_check_string_type(RARRAY_PTR(load_path)[i]);
        if (NIL_P(str) || !rb_is_absolute_path(RSTRING_PTR(str)))
            goto relative_path_found;
    }
    return load_path;

  relative_path_found:
    ary = rb_ary_new2(RARRAY_LEN(load_path));
    for (i = 0; i < RARRAY_LEN(load_path); ++i) {
        VALUE path = rb_file_expand_path(RARRAY_PTR(load_path)[i], Qnil);
        rb_str_freeze(path);
        rb_ary_push(ary, path);
    }
    rb_obj_freeze(ary);
    return ary;
}

static VALUE
load_path_getter(ID id, rb_vm_t *vm)
{
    return vm->load_path;
}

static VALUE
get_loaded_features(void)
{
    return GET_VM()->loaded_features;
}

static st_table *
get_loading_table(void)
{
    return GET_VM()->loading_table;
}

static VALUE
loaded_feature_path(const char *name, long vlen, const char *feature, long len,
                    int type, VALUE load_path)
{
    long i;

    for (i = 0; i < RARRAY_LEN(load_path); ++i) {
        VALUE p = RARRAY_PTR(load_path)[i];
        const char *s = StringValuePtr(p);
        long n = RSTRING_LEN(p);

        if (vlen < n + len + 1) continue;
        if (n && (strncmp(name, s, n) || name[n] != '/')) continue;
        if (strncmp(name + n + 1, feature, len)) continue;
        if (name[n+len+1] && name[n+len+1] != '.') continue;
        switch (type) {
          case 's':
            if (IS_DLEXT(&name[n+len+1])) return p;
            break;
          case 'r':
            if (IS_RBEXT(&name[n+len+1])) return p;
            break;
          default:
            return p;
        }
    }
    return 0;
}

struct loaded_feature_searching {
    const char *name;
    long len;
    int type;
    VALUE load_path;
    const char *result;
};

static int
loaded_feature_path_i(st_data_t v, st_data_t b, st_data_t f)
{
    const char *s = (const char *)v;
    struct loaded_feature_searching *fp = (struct loaded_feature_searching *)f;
    VALUE p = loaded_feature_path(s, strlen(s), fp->name, fp->len,
                                  fp->type, fp->load_path);
    if (!p) return ST_CONTINUE;
    fp->result = s;
    return ST_STOP;
}

static int
rb_feature_p(const char *feature, const char *ext, int rb, int expanded, const char **fn)
{
    VALUE v, features, p, load_path = 0;
    const char *f, *e;
    long i, len, elen, n;
    st_table *loading_tbl;
    st_data_t data;
    int type;

    if (fn) *fn = 0;
    if (ext) {
        elen = strlen(ext);
        len = strlen(feature) - elen;
        type = rb ? 'r' : 's';
    }
    else {
        len = strlen(feature);
        elen = 0;
        type = 0;
    }
    features = get_loaded_features();
    for (i = 0; i < RARRAY_LEN(features); ++i) {
        v = RARRAY_PTR(features)[i];
        f = StringValuePtr(v);
        if ((n = RSTRING_LEN(v)) < len) continue;
        if (strncmp(f, feature, len) != 0) {
            if (expanded) continue;
            if (!load_path) load_path = rb_get_expanded_load_path();
            if (!(p = loaded_feature_path(f, n, feature, len, type, load_path)))
                continue;
            expanded = 1;
            f += RSTRING_LEN(p) + 1;
        }
        if (!*(e = f + len)) {
            if (ext) continue;
            return 'u';
        }
        if (*e != '.') continue;
        if ((!rb || !ext) && (IS_SOEXT(e) || IS_DLEXT(e))) {
            return 's';
        }
        if ((rb || !ext) && (IS_RBEXT(e))) {
            return 'r';
        }
    }
    loading_tbl = get_loading_table();
    if (loading_tbl) {
        f = 0;
        if (!expanded) {
            struct loaded_feature_searching fs;
            fs.name = feature;
            fs.len = len;
            fs.type = type;
            fs.load_path = load_path ? load_path : rb_get_load_path();
            fs.result = 0;
            st_foreach(loading_tbl, loaded_feature_path_i, (st_data_t)&fs);
            if ((f = fs.result) != 0) {
                if (fn) *fn = f;
                goto loading;
            }
        }
        if (st_get_key(loading_tbl, (st_data_t)feature, &data)) {
            if (fn) *fn = (const char*)data;
          loading:
            if (!ext) return 'u';
            return !IS_RBEXT(ext) ? 's' : 'r';
        }
        else {
            VALUE bufstr;
            char *buf;

            if (ext && *ext) return 0;
            bufstr = rb_str_tmp_new(len + DLEXT_MAXLEN);
            buf = RSTRING_PTR(bufstr);
            MEMCPY(buf, feature, char, len);
            for (i = 0; (e = loadable_ext[i]) != 0; i++) {
                strlcpy(buf + len, e, DLEXT_MAXLEN + 1);
                if (st_get_key(loading_tbl, (st_data_t)buf, &data)) {
                    rb_str_resize(bufstr, 0);
                    if (fn) *fn = (const char*)data;
                    return i ? 's' : 'r';
                }
            }
            rb_str_resize(bufstr, 0);
        }
    }
    return 0;
}

int
rb_provided(const char *feature)
{
    return rb_feature_provided(feature, 0);
}

int
rb_feature_provided(const char *feature, const char **loading)
{
    const char *ext = strrchr(feature, '.');
    volatile VALUE fullpath = 0;

    if (*feature == '.' &&
        (feature[1] == '/' || strncmp(feature+1, "./", 2) == 0)) {
        fullpath = rb_file_expand_path(rb_str_new2(feature), Qnil);
        feature = RSTRING_PTR(fullpath);
    }
    if (ext && !strchr(ext, '/')) {
        if (IS_RBEXT(ext)) {
            if (rb_feature_p(feature, ext, TRUE, FALSE, loading)) return TRUE;
            return FALSE;
        }
        else if (IS_SOEXT(ext) || IS_DLEXT(ext)) {
            if (rb_feature_p(feature, ext, FALSE, FALSE, loading)) return TRUE;
            return FALSE;
        }
    }
    if (rb_feature_p(feature, 0, TRUE, FALSE, loading))
        return TRUE;
    return FALSE;
}

static void
rb_provide_feature(VALUE feature)
{
    rb_ary_push(get_loaded_features(), feature);
}

void
rb_provide(const char *feature)
{
    rb_provide_feature(rb_usascii_str_new2(feature));
}

NORETURN(static void load_failed(VALUE));

static void
rb_load_internal(VALUE fname, int wrap)
{
    int state;
    rb_thread_t *th = GET_THREAD();
    volatile VALUE wrapper = th->top_wrapper;
    volatile VALUE self = th->top_self;
    volatile int loaded = FALSE;
    volatile int mild_compile_error;
#ifndef __GNUC__
    rb_thread_t *volatile th0 = th;
#endif

    th->errinfo = Qnil; /* ensure */

    if (!wrap) {
        rb_secure(4);           /* should alter global state */
        th->top_wrapper = 0;
    }
    else {
        /* load in anonymous module as toplevel */
        th->top_self = rb_obj_clone(rb_vm_top_self());
        th->top_wrapper = rb_module_new();
        rb_extend_object(th->top_self, th->top_wrapper);
    }

    mild_compile_error = th->mild_compile_error;
    PUSH_TAG();
    state = EXEC_TAG();
    if (state == 0) {
        NODE *node;
        VALUE iseq;

        th->mild_compile_error++;
        node = (NODE *)rb_load_file(RSTRING_PTR(fname));
        loaded = TRUE;
        iseq = rb_iseq_new_top(node, rb_str_new2("<top (required)>"), fname, fname, Qfalse);
        th->mild_compile_error--;
        rb_iseq_eval(iseq);
    }
    POP_TAG();

#ifndef __GNUC__
    th = th0;
    fname = RB_GC_GUARD(fname);
#endif
    th->mild_compile_error = mild_compile_error;
    th->top_self = self;
    th->top_wrapper = wrapper;

    if (!loaded) {
        rb_exc_raise(GET_THREAD()->errinfo);
    }
    if (state) {
        rb_vm_jump_tag_but_local_jump(state, Qundef);
    }

    if (!NIL_P(GET_THREAD()->errinfo)) {
        /* exception during load */
        rb_exc_raise(th->errinfo);
    }
}

void
rb_load(VALUE fname, int wrap)
{
    VALUE tmp = rb_find_file(FilePathValue(fname));
    if (!tmp) load_failed(fname);
    rb_load_internal(tmp, wrap);
}

void
rb_load_protect(VALUE fname, int wrap, int *state)
{
    int status;

    PUSH_TAG();
    if ((status = EXEC_TAG()) == 0) {
        rb_load(fname, wrap);
    }
    POP_TAG();
    if (state)
        *state = status;
}

/*
 *  call-seq:
 *     load(filename, wrap=false)   -> true
 *
 *  Loads and executes the Ruby
 *  program in the file _filename_. If the filename does not
 *  resolve to an absolute path, the file is searched for in the library
 *  directories listed in <code>$:</code>. If the optional _wrap_
 *  parameter is +true+, the loaded script will be executed
 *  under an anonymous module, protecting the calling program's global
 *  namespace. In no circumstance will any local variables in the loaded
 *  file be propagated to the loading environment.
 */

static VALUE
rb_f_load(int argc, VALUE *argv)
{
    VALUE fname, wrap, path;

    rb_scan_args(argc, argv, "11", &fname, &wrap);
    path = rb_find_file(FilePathValue(fname));
    if (!path) {
        if (!rb_file_load_ok(RSTRING_PTR(fname)))
            load_failed(fname);
        path = fname;
    }
    rb_load_internal(path, RTEST(wrap));
    return Qtrue;
}

static char *
load_lock(const char *ftptr)
{
    st_data_t data;
    st_table *loading_tbl = get_loading_table();

    if (!loading_tbl || !st_lookup(loading_tbl, (st_data_t)ftptr, &data)) {
        /* loading ruby library should be serialized. */
        if (!loading_tbl) {
            GET_VM()->loading_table = loading_tbl = st_init_strtable();
        }
        /* partial state */
        ftptr = ruby_strdup(ftptr);
        data = (st_data_t)rb_barrier_new();
        st_insert(loading_tbl, (st_data_t)ftptr, data);
        return (char *)ftptr;
    }
    if (RTEST(ruby_verbose)) {
        rb_warning("loading in progress, circular require considered harmful - %s", ftptr);
        rb_backtrace();
    }
    return RTEST(rb_barrier_wait((VALUE)data)) ? (char *)ftptr : 0;
}

static void
load_unlock(const char *ftptr, int done)
{
    if (ftptr) {
        st_data_t key = (st_data_t)ftptr;
        st_data_t data;
        st_table *loading_tbl = get_loading_table();

        if (st_delete(loading_tbl, &key, &data)) {
            VALUE barrier = (VALUE)data;
            xfree((char *)key);
            if (done)
                rb_barrier_destroy(barrier);
            else
                rb_barrier_release(barrier);
        }
    }
}


/*
 *  call-seq:
 *     require(string)    -> true or false
 *
 *  Ruby tries to load the library named _string_, returning
 *  +true+ if successful. If the filename does not resolve to
 *  an absolute path, it will be searched for in the directories listed
 *  in <code>$:</code>. If the file has the extension ``.rb'', it is
 *  loaded as a source file; if the extension is ``.so'', ``.o'', or
 *  ``.dll'', or whatever the default shared library extension is on
 *  the current platform, Ruby loads the shared library as a Ruby
 *  extension. Otherwise, Ruby tries adding ``.rb'', ``.so'', and so on
 *  to the name. The name of the loaded feature is added to the array in
 *  <code>$"</code>. A feature will not be loaded if its name already
 *  appears in <code>$"</code>. The file name is converted to an absolute
 *  path, so ``<code>require 'a'; require './a'</code>'' will not load
 *  <code>a.rb</code> twice.
 *
 *     require "my-library.rb"
 *     require "db-driver"
 */

VALUE
rb_f_require(VALUE obj, VALUE fname)
{
    return rb_require_safe(fname, rb_safe_level());
}

VALUE
rb_f_require_relative(VALUE obj, VALUE fname)
{
    VALUE rb_current_realfilepath(void);
    VALUE base = rb_current_realfilepath();
    if (NIL_P(base)) {
        rb_raise(rb_eLoadError, "cannot infer basepath");
    }
    base = rb_file_dirname(base);
    return rb_require_safe(rb_file_absolute_path(fname, base), rb_safe_level());
}

static int
search_required(VALUE fname, volatile VALUE *path, int safe_level)
{
    VALUE tmp;
    char *ext, *ftptr;
    int type, ft = 0;
    const char *loading;

    *path = 0;
    ext = strrchr(ftptr = RSTRING_PTR(fname), '.');
    if (ext && !strchr(ext, '/')) {
        if (IS_RBEXT(ext)) {
            if (rb_feature_p(ftptr, ext, TRUE, FALSE, &loading)) {
                if (loading) *path = rb_str_new2(loading);
                return 'r';
            }
            if ((tmp = rb_find_file_safe(fname, safe_level)) != 0) {
                ext = strrchr(ftptr = RSTRING_PTR(tmp), '.');
                if (!rb_feature_p(ftptr, ext, TRUE, TRUE, &loading) || loading)
                    *path = tmp;
                return 'r';
            }
            return 0;
        }
        else if (IS_SOEXT(ext)) {
            if (rb_feature_p(ftptr, ext, FALSE, FALSE, &loading)) {
                if (loading) *path = rb_str_new2(loading);
                return 's';
            }
            tmp = rb_str_new(RSTRING_PTR(fname), ext - RSTRING_PTR(fname));
#ifdef DLEXT2
            OBJ_FREEZE(tmp);
            if (rb_find_file_ext_safe(&tmp, loadable_ext + 1, safe_level)) {
                ext = strrchr(ftptr = RSTRING_PTR(tmp), '.');
                if (!rb_feature_p(ftptr, ext, FALSE, TRUE, &loading) || loading)
                    *path = tmp;
                return 's';
            }
#else
            rb_str_cat2(tmp, DLEXT);
            OBJ_FREEZE(tmp);
            if ((tmp = rb_find_file_safe(tmp, safe_level)) != 0) {
                ext = strrchr(ftptr = RSTRING_PTR(tmp), '.');
                if (!rb_feature_p(ftptr, ext, FALSE, TRUE, &loading) || loading)
                    *path = tmp;
                return 's';
            }
#endif
        }
        else if (IS_DLEXT(ext)) {
            if (rb_feature_p(ftptr, ext, FALSE, FALSE, &loading)) {
                if (loading) *path = rb_str_new2(loading);
                return 's';
            }
            if ((tmp = rb_find_file_safe(fname, safe_level)) != 0) {
                ext = strrchr(ftptr = RSTRING_PTR(tmp), '.');
                if (!rb_feature_p(ftptr, ext, FALSE, TRUE, &loading) || loading)
                    *path = tmp;
                return 's';
            }
        }
    }
    else if ((ft = rb_feature_p(ftptr, 0, FALSE, FALSE, &loading)) == 'r') {
        if (loading) *path = rb_str_new2(loading);
        return 'r';
    }
    tmp = fname;
    type = rb_find_file_ext_safe(&tmp, loadable_ext, safe_level);
    switch (type) {
      case 0:
        if (ft)
            break;
        ftptr = RSTRING_PTR(tmp);
        return rb_feature_p(ftptr, 0, FALSE, TRUE, 0);

      default:
        if (ft)
            break;
      case 1:
        ext = strrchr(ftptr = RSTRING_PTR(tmp), '.');
        if (rb_feature_p(ftptr, ext, !--type, TRUE, &loading) && !loading)
            break;
        *path = tmp;
    }
    return type ? 's' : 'r';
}

static void
load_failed(VALUE fname)
{
    VALUE mesg = rb_str_buf_new_cstr("no such file to load -- ");
    rb_str_append(mesg, fname); /* should be ASCII compatible */
    rb_exc_raise(rb_exc_new3(rb_eLoadError, mesg));
}

static VALUE
load_ext(VALUE path)
{
    SCOPE_SET(NOEX_PUBLIC);
    return (VALUE)dln_load(RSTRING_PTR(path));
}

VALUE
rb_require_safe(VALUE fname, int safe)
{
    volatile VALUE result = Qnil;
    rb_thread_t *th = GET_THREAD();
    volatile VALUE errinfo = th->errinfo;
    int state;
    struct {
        int safe;
    } volatile saved;
    char *volatile ftptr = 0;

    PUSH_TAG();
    saved.safe = rb_safe_level();
    if ((state = EXEC_TAG()) == 0) {
        VALUE path;
        long handle;
        int found;

        rb_set_safe_level_force(safe);
        FilePathValue(fname);
        rb_set_safe_level_force(0);
        found = search_required(fname, &path, safe);
        if (found) {
            if (!path || !(ftptr = load_lock(RSTRING_PTR(path)))) {
                result = Qfalse;
            }
            else {
                switch (found) {
                  case 'r':
                    rb_load_internal(path, 0);
                    break;

                  case 's':
                    handle = (long)rb_vm_call_cfunc(rb_vm_top_self(), load_ext,
                                                    path, 0, path, path);
                    rb_ary_push(ruby_dln_librefs, LONG2NUM(handle));
                    break;
                }
                rb_provide_feature(path);
                result = Qtrue;
            }
        }
    }
    POP_TAG();
    load_unlock(ftptr, !state);

    rb_set_safe_level_force(saved.safe);
    if (state) {
        JUMP_TAG(state);
    }

    if (NIL_P(result)) {
        load_failed(fname);
    }

    th->errinfo = errinfo;

    return result;
}

VALUE
rb_require(const char *fname)
{
    VALUE fn = rb_str_new2(fname);
    OBJ_FREEZE(fn);
    return rb_require_safe(fn, rb_safe_level());
}

static VALUE
init_ext_call(VALUE arg)
{
    SCOPE_SET(NOEX_PUBLIC);
    (*(void (*)(void))arg)();
    return Qnil;
}

void
ruby_init_ext(const char *name, void (*init)(void))
{
    if (load_lock(name)) {
        rb_vm_call_cfunc(rb_vm_top_self(), init_ext_call, (VALUE)init,
                         0, rb_str_new2(name), Qnil);
        rb_provide(name);
        load_unlock(name, 1);
    }
}

/*
 *  call-seq:
 *     mod.autoload(module, filename)   -> nil
 *
 *  Registers _filename_ to be loaded (using <code>Kernel::require</code>)
 *  the first time that _module_ (which may be a <code>String</code> or
 *  a symbol) is accessed in the namespace of _mod_.
 *
 *     module A
 *     end
 *     A.autoload(:B, "b")
 *     A::B.doit            # autoloads "b"
 */

static VALUE
rb_mod_autoload(VALUE mod, VALUE sym, VALUE file)
{
    ID id = rb_to_id(sym);

    FilePathValue(file);
    rb_autoload(mod, id, RSTRING_PTR(file));
    return Qnil;
}

/*
 *  call-seq:
 *     mod.autoload?(name)   -> String or nil
 *
 *  Returns _filename_ to be loaded if _name_ is registered as
 *  +autoload+ in the namespace of _mod_.
 *
 *     module A
 *     end
 *     A.autoload(:B, "b")
 *     A.autoload?(:B)            #=> "b"
 */

static VALUE
rb_mod_autoload_p(VALUE mod, VALUE sym)
{
    return rb_autoload_p(mod, rb_to_id(sym));
}

/*
 *  call-seq:
 *     autoload(module, filename)   -> nil
 *
 *  Registers _filename_ to be loaded (using <code>Kernel::require</code>)
 *  the first time that _module_ (which may be a <code>String</code> or
 *  a symbol) is accessed.
 *
 *     autoload(:MyModule, "/usr/local/lib/modules/my_module.rb")
 */

static VALUE
rb_f_autoload(VALUE obj, VALUE sym, VALUE file)
{
    VALUE klass = rb_vm_cbase();
    if (NIL_P(klass)) {
        rb_raise(rb_eTypeError, "Can not set autoload on singleton class");
    }
    return rb_mod_autoload(klass, sym, file);
}

/*
 *  call-seq:
 *     autoload?(name)   -> String or nil
 *
 *  Returns _filename_ to be loaded if _name_ is registered as
 *  +autoload+.
 *
 *     autoload(:B, "b")
 *     autoload?(:B)            #=> "b"
 */

static VALUE
rb_f_autoload_p(VALUE obj, VALUE sym)
{
    /* use rb_vm_cbase() as same as rb_f_autoload. */
    VALUE klass = rb_vm_cbase();
    if (NIL_P(klass)) {
        return Qnil;
    }
    return rb_mod_autoload_p(klass, sym);
}

void
Init_load()
{
#undef rb_intern
#define rb_intern(str) rb_intern2(str, strlen(str))
    rb_vm_t *vm = GET_VM();
    static const char var_load_path[] = "$:";
    ID id_load_path = rb_intern2(var_load_path, sizeof(var_load_path)-1);

    rb_define_hooked_variable(var_load_path, (VALUE*)vm, load_path_getter, rb_gvar_readonly_setter);
    rb_alias_variable(rb_intern("$-I"), id_load_path);
    rb_alias_variable(rb_intern("$LOAD_PATH"), id_load_path);
    vm->load_path = rb_ary_new();

    rb_define_virtual_variable("$\"", get_loaded_features, 0);
    rb_define_virtual_variable("$LOADED_FEATURES", get_loaded_features, 0);
    vm->loaded_features = rb_ary_new();

    rb_define_global_function("load", rb_f_load, -1);
    rb_define_global_function("require", rb_f_require, 1);
    rb_define_global_function("require_relative", rb_f_require_relative, 1);
    rb_define_method(rb_cModule, "autoload", rb_mod_autoload, 2);
    rb_define_method(rb_cModule, "autoload?", rb_mod_autoload_p, 1);
    rb_define_global_function("autoload", rb_f_autoload, 2);
    rb_define_global_function("autoload?", rb_f_autoload_p, 1);

    ruby_dln_librefs = rb_ary_new();
    rb_gc_register_mark_object(ruby_dln_librefs);
}