Fiddle::Function

class Fiddle::Function

Parent:Object

描述

C函数的表示

例子

'strcpy'

@libc = Fiddle.dlopen "/lib/libc.so.6"
   #=> #<Fiddle::Handle:0x00000001d7a8d8>
f = Fiddle::Function.new(
  @libc['strcpy'],
  [Fiddle::TYPE_VOIDP, Fiddle::TYPE_VOIDP],
  Fiddle::TYPE_VOIDP)
   #=> #<Fiddle::Function:0x00000001d8ee00>
buff = "000"
   #=> "000"
str = f.call(buff, "123")
   #=> #<Fiddle::Pointer:0x00000001d0c380 ptr=0x000000018a21b8 size=0 free=0x00000000000000>
str.to_s
=> "123"

ABI检查

@libc = Fiddle.dlopen "/lib/libc.so.6"
   #=> #<Fiddle::Handle:0x00000001d7a8d8>
f = Fiddle::Function.new(@libc['strcpy'], [TYPE_VOIDP, TYPE_VOIDP], TYPE_VOIDP)
   #=> #<Fiddle::Function:0x00000001d8ee00>
f.abi == Fiddle::Function::DEFAULT
   #=> true

常量

DEFAULT

Default ABI

STDCALL

FFI执行WIN32 stdcall约定

属性

abiR

函数的ABI。

nameR

这个函数的名字

ptrR

这个函数的地址

公共类方法

new(ptr, args, ret_type, abi = DEFAULT) Show source

构造一个Function对象。

ptr 是一个Fiddle :: Handle的引用函数

args是传递给ptr函数的一个参数数组

ret_type 是函数的返回类型

abi 是函数的ABI

static VALUE
initialize(int argc, VALUE argv[], VALUE self)
{
    ffi_cif * cif;
    ffi_type **arg_types, *rtype;
    ffi_status result;
    VALUE ptr, args, ret_type, abi, kwds, ary;
    int i, len;
    int nabi;
    void *cfunc;

    rb_scan_args(argc, argv, "31:", &ptr, &args, &ret_type, &abi, &kwds
    ptr = rb_Integer(ptr
    cfunc = NUM2PTR(ptr
    PTR2NUM(cfunc
    nabi = NIL_P(abi) ? FFI_DEFAULT_ABI : NUM2INT(abi
    abi = INT2FIX(nabi
    i = NUM2INT(ret_type
    rtype = INT2FFI_TYPE(i
    ret_type = INT2FIX(i

    Check_Type(args, T_ARRAY
    len = RARRAY_LENINT(args
    Check_Max_Args("args", len
    ary = rb_ary_subseq(args, 0, len
    for (i = 0; i < RARRAY_LEN(args i++) {
        VALUE a = RARRAY_PTR(args)[i];
        int type = NUM2INT(a
        (void)INT2FFI_TYPE(type /* raise */
        if (INT2FIX(type) != a) rb_ary_store(ary, i, INT2FIX(type)
    }
    OBJ_FREEZE(ary

    rb_iv_set(self, "@ptr", ptr
    rb_iv_set(self, "@args", args
    rb_iv_set(self, "@return_type", ret_type
    rb_iv_set(self, "@abi", abi

    if (!NIL_P(kwds)) rb_hash_foreach(kwds, parse_keyword_arg_i, self

    TypedData_Get_Struct(self, ffi_cif, &function_data_type, cif

    arg_types = xcalloc(len + 1, sizeof(ffi_type *)

    for (i = 0; i < RARRAY_LEN(args i++) {
        int type = NUM2INT(RARRAY_AREF(args, i)
        arg_types[i] = INT2FFI_TYPE(type
    }
    arg_types[len] = NULL;

    result = ffi_prep_cif(cif, nabi, len, rtype, arg_types

    if (result)
        rb_raise(rb_eRuntimeError, "error creating CIF %d", result

    return self;
}

公共实例方法

call(*args) Show source

调用构造函数args。如果在多线程进程中运行，调用者必须确保底层函数以线程安全方式调用。

有关示例，请参阅Fiddle :: Function

static VALUE
function_call(int argc, VALUE argv[], VALUE self)
{
    struct nogvl_ffi_call_args args = { 0 };
    fiddle_generic *generic_args;
    VALUE cfunc, types, cPointer;
    int i;
    VALUE alloc_buffer = 0;

    cfunc    = rb_iv_get(self, "@ptr"
    types    = rb_iv_get(self, "@args"
    cPointer = rb_const_get(mFiddle, rb_intern("Pointer")

    Check_Max_Args("number of arguments", argc
    if (argc != (i = RARRAY_LENINT(types))) {
        rb_error_arity(argc, i, i
    }

    TypedData_Get_Struct(self, ffi_cif, &function_data_type, args.cif

    if (rb_safe_level() >= 1) {
        for (i = 0; i < argc; i++) {
            VALUE src = argv[i];
            if (OBJ_TAINTED(src)) {
                rb_raise(rb_eSecurityError, "tainted parameter not allowed"
            }
        }
    }

    generic_args = ALLOCV(alloc_buffer,
        (size_t)(argc + 1) * sizeof(void *) + (size_t)argc * sizeof(fiddle_generic)
    args.values = (void **)((char *)generic_args +
                            (size_t)argc * sizeof(fiddle_generic)

    for (i = 0; i < argc; i++) {
        VALUE type = RARRAY_AREF(types, i
        VALUE src = argv[i];
        int argtype = FIX2INT(type

        if (argtype == TYPE_VOIDP) {
            if(NIL_P(src)) {
                src = INT2FIX(0
            } else if(cPointer != CLASS_OF(src)) {
                src = rb_funcall(cPointer, rb_intern("[]"), 1, src
            }
            src = rb_Integer(src
        }

        VALUE2GENERIC(argtype, src, &generic_args[i]
        args.values[i] = (void *)&generic_args[i];
    }
    args.values[argc] = NULL;
    args.fn = NUM2PTR(cfunc

    (void)rb_thread_call_without_gvl(nogvl_ffi_call, &args, 0, 0

    rb_funcall(mFiddle, rb_intern("last_error="), 1, INT2NUM(errno)
#if defined(_WIN32)
    rb_funcall(mFiddle, rb_intern("win32_last_error="), 1, INT2NUM(errno)
#endif

    ALLOCV_END(alloc_buffer

    return GENERIC2VALUE(rb_iv_get(self, "@return_type"), args.retval
}

to_i() Show source

该函数的整数存储位置

# File ext/fiddle/lib/fiddle/function.rb, line 13
def to_i
  ptr.to_i
end