Class: Fiddle::Function
- Inherits:
-
Object
- Object
- Fiddle::Function
- Defined in:
- function.c,
lib/fiddle/function.rb,
function.c
Overview
Description
A representation of a C function
Examples
‘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 check
@libc = DL.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
Constant Summary collapse
- DEFAULT =
Default ABI
INT2NUM(FFI_DEFAULT_ABI)
- STDCALL =
FFI implementation of WIN32 stdcall convention
INT2NUM(FFI_STDCALL)
Instance Attribute Summary collapse
-
#abi ⇒ Object
readonly
The ABI of the Function.
-
#name ⇒ Object
readonly
The name of this function.
-
#ptr ⇒ Object
readonly
The address of this function.
Instance Method Summary collapse
-
#call ⇒ Object
Calls the constructed Function, with
args
. -
#new(ptr, args, ret_type, abi = DEFAULT) ⇒ Object
constructor
Constructs a Function object.
-
#to_i ⇒ Object
The integer memory location of this function.
Constructor Details
#new(ptr, args, ret_type, abi = DEFAULT) ⇒ Object
Constructs a Function object.
-
ptr
is a referenced function, of a Fiddle::Handle -
args
is an Array of arguments, passed to theptr
function -
ret_type
is the return type of the function -
abi
is the ABI of the function
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# File 'function.c', line 64
static VALUE
initialize(int argc, VALUE argv[], VALUE self)
{
ffi_cif * cif;
ffi_type **arg_types;
ffi_status result;
VALUE ptr, args, ret_type, abi, kwds;
int i;
rb_scan_args(argc, argv, "31:", &ptr, &args, &ret_type, &abi, &kwds);
if(NIL_P(abi)) abi = INT2NUM(FFI_DEFAULT_ABI);
Check_Type(args, T_ARRAY);
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(RARRAY_LEN(args) + 1, sizeof(ffi_type *));
for (i = 0; i < RARRAY_LEN(args); i++) {
int type = NUM2INT(RARRAY_PTR(args)[i]);
arg_types[i] = INT2FFI_TYPE(type);
}
arg_types[RARRAY_LEN(args)] = NULL;
result = ffi_prep_cif (
cif,
NUM2INT(abi),
RARRAY_LENINT(args),
INT2FFI_TYPE(NUM2INT(ret_type)),
arg_types);
if (result)
rb_raise(rb_eRuntimeError, "error creating CIF %d", result);
return self;
}
|
Instance Attribute Details
#abi ⇒ Object (readonly)
The ABI of the Function.
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# File 'lib/fiddle/function.rb', line 4 def abi @abi end |
#name ⇒ Object (readonly)
The name of this function
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# File 'lib/fiddle/function.rb', line 10 def name @name end |
#ptr ⇒ Object (readonly)
The address of this function
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# File 'lib/fiddle/function.rb', line 7 def ptr @ptr end |
Instance Method Details
#call ⇒ Object
Calls the constructed Function, with args
For an example see Fiddle::Function
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# File 'function.c', line 108
static VALUE
function_call(int argc, VALUE argv[], VALUE self)
{
ffi_cif * cif;
fiddle_generic retval;
fiddle_generic *generic_args;
void **values;
VALUE cfunc, types, cPointer;
int i;
cfunc = rb_iv_get(self, "@ptr");
types = rb_iv_get(self, "@args");
cPointer = rb_const_get(mFiddle, rb_intern("Pointer"));
if(argc != RARRAY_LENINT(types)) {
rb_raise(rb_eArgError, "wrong number of arguments (%d for %d)",
argc, RARRAY_LENINT(types));
}
TypedData_Get_Struct(self, ffi_cif, &function_data_type, 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");
}
}
}
values = xcalloc((size_t)argc + 1, (size_t)sizeof(void *));
generic_args = xcalloc((size_t)argc, (size_t)sizeof(fiddle_generic));
for (i = 0; i < argc; i++) {
VALUE type = RARRAY_PTR(types)[i];
VALUE src = argv[i];
if(NUM2INT(type) == 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(NUM2INT(type), src, &generic_args[i]);
values[i] = (void *)&generic_args[i];
}
values[argc] = NULL;
ffi_call(cif, NUM2PTR(rb_Integer(cfunc)), &retval, values);
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
xfree(values);
xfree(generic_args);
return GENERIC2VALUE(rb_iv_get(self, "@return_type"), retval);
}
|
#to_i ⇒ Object
The integer memory location of this function
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# File 'lib/fiddle/function.rb', line 13 def to_i ptr.to_i end |