Class: FFI::FunctionType

Inherits:

Type

• Object
• Type
• FFI::FunctionType

Defined in:

ext/ffi_c/FunctionInfo.c

Instance Method Summary

• #initialize(return_type, param_types, options = {}) ⇒ self constructor

  A new FunctionType instance.

• #param_types ⇒ Array<Type>

  Get parameters types.

• #result_type ⇒ Type

  Get the return type of the function type.

Constructor Details

#initialize(return_type, param_types, options = {}) ⇒ self

A new FunctionType instance.

Parameters:

• return_type (Type, Symbol) —

  return type for the function

• param_types (Array<Type, Symbol>) —

  array of parameters types

• options (Hash)

# File 'ext/ffi_c/FunctionInfo.c', line 115

static VALUE
fntype_initialize(int argc, VALUE* argv, VALUE self)
{
    FunctionType *fnInfo;
    ffi_status status;
    VALUE rbReturnType = Qnil, rbParamTypes = Qnil, rbOptions = Qnil;
    VALUE rbEnums = Qnil, rbConvention = Qnil, rbBlocking = Qnil;
#if defined(X86_WIN32)
    VALUE rbConventionStr;
#endif
    int i, nargs;

    nargs = rb_scan_args(argc, argv, "21", &rbReturnType, &rbParamTypes, &rbOptions);
    if (nargs >= 3 && rbOptions != Qnil) {
        rbConvention = rb_hash_aref(rbOptions, ID2SYM(rb_intern("convention")));
        rbEnums = rb_hash_aref(rbOptions, ID2SYM(rb_intern("enums")));
        rbBlocking = rb_hash_aref(rbOptions, ID2SYM(rb_intern("blocking")));
    }

    Check_Type(rbParamTypes, T_ARRAY);

    Data_Get_Struct(self, FunctionType, fnInfo);
    fnInfo->parameterCount = (int) RARRAY_LEN(rbParamTypes);
    fnInfo->parameterTypes = xcalloc(fnInfo->parameterCount, sizeof(*fnInfo->parameterTypes));
    fnInfo->ffiParameterTypes = xcalloc(fnInfo->parameterCount, sizeof(ffi_type *));
    fnInfo->nativeParameterTypes = xcalloc(fnInfo->parameterCount, sizeof(*fnInfo->nativeParameterTypes));
    fnInfo->rbParameterTypes = rb_ary_new2(fnInfo->parameterCount);
    fnInfo->rbEnums = rbEnums;
    fnInfo->blocking = RTEST(rbBlocking);
    fnInfo->hasStruct = false;

    for (i = 0; i < fnInfo->parameterCount; ++i) {
        VALUE entry = rb_ary_entry(rbParamTypes, i);
        VALUE type = rbffi_Type_Lookup(entry);

        if (!RTEST(type)) {
            VALUE typeName = rb_funcall2(entry, rb_intern("inspect"), 0, NULL);
            rb_raise(rb_eTypeError, "Invalid parameter type (%s)", RSTRING_PTR(typeName));
        }

        if (rb_obj_is_kind_of(type, rbffi_FunctionTypeClass)) {
            REALLOC_N(fnInfo->callbackParameters, VALUE, fnInfo->callbackCount + 1);
            fnInfo->callbackParameters[fnInfo->callbackCount++] = type;
        }

        if (rb_obj_is_kind_of(type, rbffi_StructByValueClass)) {
            fnInfo->hasStruct = true;
        }

        rb_ary_push(fnInfo->rbParameterTypes, type);
        Data_Get_Struct(type, Type, fnInfo->parameterTypes[i]);
        fnInfo->ffiParameterTypes[i] = fnInfo->parameterTypes[i]->ffiType;
        fnInfo->nativeParameterTypes[i] = fnInfo->parameterTypes[i]->nativeType;
    }

    fnInfo->rbReturnType = rbffi_Type_Lookup(rbReturnType);
    if (!RTEST(fnInfo->rbReturnType)) {
        VALUE typeName = rb_funcall2(rbReturnType, rb_intern("inspect"), 0, NULL);
        rb_raise(rb_eTypeError, "Invalid return type (%s)", RSTRING_PTR(typeName));
    }
    
    if (rb_obj_is_kind_of(fnInfo->rbReturnType, rbffi_StructByValueClass)) {
        fnInfo->hasStruct = true;
    }

    Data_Get_Struct(fnInfo->rbReturnType, Type, fnInfo->returnType);
    fnInfo->ffiReturnType = fnInfo->returnType->ffiType;


#if defined(X86_WIN32)
    rbConventionStr = (rbConvention != Qnil) ? rb_funcall2(rbConvention, rb_intern("to_s"), 0, NULL) : Qnil;
    fnInfo->abi = (rbConventionStr != Qnil && strcmp(StringValueCStr(rbConventionStr), "stdcall") == 0)
            ? FFI_STDCALL : FFI_DEFAULT_ABI;
#else
    fnInfo->abi = FFI_DEFAULT_ABI;
#endif

    status = ffi_prep_cif(&fnInfo->ffi_cif, fnInfo->abi, fnInfo->parameterCount,
            fnInfo->ffiReturnType, fnInfo->ffiParameterTypes);
    switch (status) {
        case FFI_BAD_ABI:
            rb_raise(rb_eArgError, "Invalid ABI specified");
        case FFI_BAD_TYPEDEF:
            rb_raise(rb_eArgError, "Invalid argument type specified");
        case FFI_OK:
            break;
        default:
            rb_raise(rb_eArgError, "Unknown FFI error");
    }

    fnInfo->invoke = rbffi_GetInvoker(fnInfo);

    return self;
}

Instance Method Details

#param_types ⇒ Array<Type>

Get parameters types.

Returns:

• (Array<Type>)

# File 'ext/ffi_c/FunctionInfo.c', line 230

static VALUE
fntype_param_types(VALUE self)
{
    FunctionType* ft;

    Data_Get_Struct(self, FunctionType, ft);

    return rb_ary_dup(ft->rbParameterTypes);
}

#result_type ⇒ Type

Get the return type of the function type

Returns:

• (Type)

# File 'ext/ffi_c/FunctionInfo.c', line 215

static VALUE
fntype_result_type(VALUE self)
{
    FunctionType* ft;

    Data_Get_Struct(self, FunctionType, ft);

    return ft->rbReturnType;
}