diff --git a/.gitignore b/.gitignore
index f66d718..96e0f3e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,3 +45,4 @@ testfile.test
 testfile.test
 snow
 foreign/c/lib
+!foreign/c/primitives/gauche/*.c
diff --git a/foreign/c/primitives/gauche/foreign-c-primitives-gauche.c b/foreign/c/primitives/gauche/foreign-c-primitives-gauche.c
new file mode 100644
index 0000000..285a2e0
--- /dev/null
+++ b/foreign/c/primitives/gauche/foreign-c-primitives-gauche.c
@@ -0,0 +1,815 @@
+#include <math.h>
+#include <stdint.h>
+#include <gauche.h>
+#include <gauche/extend.h>
+#include <gauche/module.h>
+#include <gauche/load.h>
+#include <gauche/number.h>
+#include <gauche/string.h>
+#include <foreign-c-primitives-gauche.h>
+#include <ffi.h>
+#include <dlfcn.h>
+
+void print_pointer(ScmObj obj, ScmPort* sink, ScmWriteContext* G1788 SCM_UNUSED) {
+    void* p = SCM_FOREIGN_POINTER_REF(void*, obj);
+    if(p == NULL) {
+        Scm_Printf(sink, "<pointer: (null)>\n");
+    } else {
+        Scm_Printf(sink, "<pointer: %i>\n", &p);
+    }
+}
+
+ScmObj size_of_int8() { return Scm_MakeInteger(sizeof(int8_t)); }
+ScmObj size_of_uint8() { return Scm_MakeInteger(sizeof(uint8_t)); }
+ScmObj size_of_int16() { return Scm_MakeInteger(sizeof(int16_t)); }
+ScmObj size_of_uint16() { return Scm_MakeInteger(sizeof(uint16_t)); }
+ScmObj size_of_int32() { return Scm_MakeInteger(sizeof(int32_t)); }
+ScmObj size_of_uint32() { return Scm_MakeInteger(sizeof(uint32_t)); }
+ScmObj size_of_int64() { return Scm_MakeInteger(sizeof(int64_t)); }
+ScmObj size_of_uint64() { return Scm_MakeInteger(sizeof(uint64_t)); }
+ScmObj size_of_char() { return Scm_MakeInteger(sizeof(char)); }
+ScmObj size_of_unsigned_char() { return Scm_MakeInteger(sizeof(unsigned char)); }
+ScmObj size_of_short() { return Scm_MakeInteger(sizeof(short)); }
+ScmObj size_of_unsigned_short() { return Scm_MakeInteger(sizeof(unsigned short)); }
+ScmObj size_of_int() { return Scm_MakeInteger(sizeof(int)); }
+ScmObj size_of_unsigned_int() { return Scm_MakeInteger(sizeof(unsigned int)); }
+ScmObj size_of_long() { return Scm_MakeInteger(sizeof(long)); }
+ScmObj size_of_unsigned_long() { return Scm_MakeInteger(sizeof(unsigned long)); }
+ScmObj size_of_float() { return Scm_MakeInteger(sizeof(float)); }
+ScmObj size_of_double() { return Scm_MakeInteger(sizeof(double)); }
+ScmObj size_of_string() { return Scm_MakeInteger(sizeof(char*)); }
+ScmObj size_of_pointer() { return Scm_MakeInteger(sizeof(void*)); }
+ScmObj size_of_void() { return Scm_MakeInteger(sizeof(void)); }
+
+ScmModule* module = NULL;
+
+ScmObj shared_object_load(ScmString* path, ScmObj options) {
+    const ScmStringBody* body = SCM_STRING_BODY(path);
+    const char* c_path = SCM_STRING_BODY_START(body);
+    void* shared_object = dlopen(c_path, RTLD_NOW);
+    ScmClass* shared_object_class = Scm_MakeForeignPointerClass(module, "shared-object", print_pointer, NULL, 0);
+    ScmObj scm_shared_object = Scm_MakeForeignPointer(shared_object_class, shared_object);
+    return scm_shared_object;
+}
+
+/*
+ScmObj pointer_null() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    ScmObj pointer = Scm_MakeForeignPointer(pointer_class, NULL);
+    return pointer;
+}
+*/
+
+/*
+ScmObj is_pointer_null(ScmObj pointer) {
+    if(!Scm_TypeP(pointer, SCM_CLASS_FOREIGN_POINTER)) {
+        return SCM_FALSE;
+    }
+    if(SCM_FOREIGN_POINTER_REF(void*, pointer) == NULL) {
+        return SCM_TRUE;
+    } else {
+        return SCM_FALSE;
+    }
+}
+*/
+
+/*
+ScmObj pointer_allocate(int size) {
+    void* p = malloc(size);
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    ScmObj pointer = Scm_MakeForeignPointer(pointer_class, p);
+    return pointer;
+}
+*/
+
+/*
+ScmObj pointer_address(ScmObj pointer) {
+    if(!Scm_TypeP(pointer, SCM_CLASS_FOREIGN_POINTER)) {
+        Scm_Error("Can only get pointer address of a pointer");
+        return SCM_UNDEFINED;
+    }
+    void* p = SCM_FOREIGN_POINTER_REF(void*, p);
+    //ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    //ScmObj address = Scm_MakeForeignPointer(pointer_class, p);
+    printf("HERE: %u", (uint64_t)&p);
+    return SCM_MAKE_INT((uint64_t)&p);
+}
+*/
+
+ScmObj is_pointer(ScmObj pointer) {
+    if(Scm_TypeP(pointer, SCM_CLASS_FOREIGN_POINTER)) {
+        return SCM_TRUE;
+    } else {
+        return SCM_FALSE;
+    }
+}
+
+/*
+ScmObj pointer_free(ScmObj pointer) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        free(SCM_FOREIGN_POINTER_REF(void*, pointer));
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_int8(ScmObj pointer, int offset, int8_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(int8_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+*/
+
+ScmObj pointer_set_uint8(ScmObj pointer, int offset, uint8_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(uint8_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+/*
+ScmObj pointer_set_int16(ScmObj pointer, int offset, int16_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(int16_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_uint16(ScmObj pointer, int offset, uint16_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(uint16_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_int32(ScmObj pointer, int offset, int32_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(int32_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_uint32(ScmObj pointer, int offset, uint32_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(uint32_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_int64(ScmObj pointer, int offset, int64_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(int64_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_uint64(ScmObj pointer, int offset, uint64_t value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(uint64_t*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_char(ScmObj pointer, int offset, char value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(char*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_unsigned_char(ScmObj pointer, int offset, unsigned char value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(unsigned char*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_short(ScmObj pointer, int offset, short value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(short*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_unsigned_short(ScmObj pointer, int offset, unsigned short value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(unsigned short*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_int(ScmObj pointer, int offset, int value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(int*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_unsigned_int(ScmObj pointer, int offset, unsigned int value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(unsigned int*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_long(ScmObj pointer, int offset, long value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(long*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_unsigned_long(ScmObj pointer, int offset, unsigned long value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(unsigned long*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_float(ScmObj pointer, int offset, float value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(float*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_set_double(ScmObj pointer, int offset, double value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        *(double*)((char*)p + offset) = value;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+*/
+
+ScmObj pointer_set_pointer(ScmObj pointer, int offset, ScmObj value) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* v = SCM_FOREIGN_POINTER_REF(void*, value);
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        char* p1 = (char*)p + offset;
+        *(char**)p1 = v;
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+/*
+
+ScmObj pointer_get_int8(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(int8_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+*/
+
+ScmObj pointer_get_uint8(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(uint8_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+/*
+ScmObj pointer_get_int16(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(int16_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_uint16(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(uint16_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_int32(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(int32_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_uint32(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(uint32_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_int64(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(int64_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_uint64(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(uint64_t*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_char(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(char*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_unsigned_char(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(unsigned char*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_short(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(short*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_unsigned_short(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(unsigned short*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_int(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(int*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_unsigned_int(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(unsigned int*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_long(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(long*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_unsigned_long(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return SCM_MAKE_INT(*(unsigned long*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_float(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return Scm_MakeFlonum(*(float*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_get_double(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        return Scm_MakeFlonum(*(double*)((char*)p + offset));
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+*/
+
+ScmObj pointer_get_pointer(ScmObj pointer, int offset) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        char* p1 = (char*)p + offset;
+        ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+        return Scm_MakeForeignPointer(pointer_class, (void*)*(char**)p1);
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+
+/*
+
+ScmObj string_to_pointer(ScmObj string) {
+    if(SCM_STRINGP(string)) {
+        ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+        return Scm_MakeForeignPointer(pointer_class, Scm_GetString(SCM_STRING(string)));
+    } else {
+        Scm_Error("Not a string: %S", string);
+    }
+    return SCM_UNDEFINED;
+}
+
+ScmObj pointer_to_string(ScmObj pointer) {
+    if(SCM_FOREIGN_POINTER_P(pointer)) {
+        void* p = SCM_FOREIGN_POINTER_REF(void*, pointer);
+        void* string = (char*)p;
+        return Scm_MakeString(string, -1, -1, 0);
+    } else {
+        Scm_Error("Not a pointer: %S", pointer);
+    }
+    return SCM_UNDEFINED;
+}
+*/
+
+ScmObj internal_dlerror() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    void* msg = dlerror();
+    if(msg == NULL) {
+        return Scm_MakeForeignPointer(pointer_class, NULL);
+    } else {
+        return Scm_MakeForeignPointer(pointer_class, msg);
+    }
+}
+
+ScmObj internal_dlsym(ScmObj shared_object, ScmObj c_name) {
+
+    if(!SCM_FOREIGN_POINTER_P(shared_object)) {
+        Scm_Error("Not a shared object: %S", shared_object);
+        return SCM_UNDEFINED;
+    }
+
+    if(!SCM_STRINGP(c_name)) {
+        Scm_Error("Not a string: %S", c_name);
+        return SCM_UNDEFINED;
+    }
+
+    void* handle = SCM_FOREIGN_POINTER_REF(void*, shared_object);
+    const ScmStringBody* body = SCM_STRING_BODY(c_name);
+    const char* name = SCM_STRING_BODY_START(body);
+    void* symbol = dlsym(handle, name);
+
+    if(symbol == NULL) {
+        Scm_Error("Could not find function %S", c_name);
+        return SCM_UNDEFINED;
+    }
+
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, symbol);
+}
+
+ScmObj get_ffi_type_int8() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_sint8);
+}
+
+ScmObj get_ffi_type_uint8() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_uint8);
+}
+
+ScmObj get_ffi_type_int16() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_sint16);
+}
+
+ScmObj get_ffi_type_uint16() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_uint16);
+}
+
+ScmObj get_ffi_type_int32() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_sint32);
+}
+
+ScmObj get_ffi_type_uint32() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_uint32);
+}
+
+ScmObj get_ffi_type_int64() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_sint64);
+}
+
+ScmObj get_ffi_type_uint64() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_uint64);
+}
+
+ScmObj get_ffi_type_char() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_schar);
+}
+
+ScmObj get_ffi_type_unsigned_char() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_uchar);
+}
+
+ScmObj get_ffi_type_short() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_sshort);
+}
+
+ScmObj get_ffi_type_unsigned_short() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_ushort);
+}
+
+ScmObj get_ffi_type_int() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_sint);
+}
+
+ScmObj get_ffi_type_unsigned_int() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_uint);
+}
+
+ScmObj get_ffi_type_long() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_slong);
+}
+
+ScmObj get_ffi_type_unsigned_long() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_ulong);
+}
+
+ScmObj get_ffi_type_float() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_float);
+}
+
+ScmObj get_ffi_type_double() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_double);
+}
+
+ScmObj get_ffi_type_void() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_void);
+}
+
+ScmObj get_ffi_type_pointer() {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, &ffi_type_pointer);
+}
+
+ScmObj internal_ffi_call(
+        ScmObj nargs,
+        ScmObj rtype,
+        ScmObj atypes,
+        ScmObj fn,
+        ScmObj rvalue_size,
+        ScmObj avalues)
+    {
+
+    ffi_cif cif;
+
+    /*
+    unsigned int c_nargs = SCM_INT_VALUE(nargs);
+    ffi_type* c_rtype = SCM_FOREIGN_POINTER_REF(ffi_type*, rtype);
+    int atypes_length = (int)Scm_Length(atypes);
+    ffi_type* c_atypes[atypes_length];
+    for(int i = 0; i < atypes_length; i++) {
+        switch(atypes[i]) {
+        }
+        //c_atypes[i] = SCM_FOREIGN_POINTER_REF(ffi_type*, Scm_ListRef(atypes, i, SCM_UNDEFINED));
+    }
+    */
+
+    unsigned int c_nargs = SCM_INT_VALUE(nargs);
+    ffi_type* c_atypes[c_nargs];
+    void* c_avalues[c_nargs];
+    uint8_t vals2[c_nargs];
+    uint64_t vals8[c_nargs];
+    int vals13[c_nargs];
+    void* vals20[c_nargs];
+
+    for(int i = 0; i < c_nargs; i++) {
+        ScmObj type = Scm_ListRef(atypes, i, SCM_UNDEFINED);
+        ScmObj value = Scm_ListRef(avalues, i, SCM_UNDEFINED);
+        switch(SCM_INT_VALUE(type)) {
+            //case 1: c_atypes[i] = &ffi_type_sint8; arg = sexp_sint_value(avalues[i]); break;
+            case 2:
+                c_atypes[i] = &ffi_type_uint8;
+                vals2[i] = (uint8_t)SCM_INT_VALUE(value);
+                c_avalues[i] = &vals2[i];
+                break;
+                //case 3: c_atypes[i] = &ffi_type_sint16; arg = sexp_sint_value(avalues[i]); break;
+                //case 4: c_atypes[i] = &ffi_type_uint16; arg = sexp_uint_value(avalues[i]); break;
+                //case 5: c_atypes[i] = &ffi_type_sint32; arg = sexp_sint_value(avalues[i]); break;
+                //case 6: c_atypes[i] = &ffi_type_uint32; arg = sexp_uint_value(avalues[i]); break;
+                //case 7: c_atypes[i] = &ffi_type_sint64; arg = sexp_sint_value(avalues[i]); break;
+            case 8:
+                c_atypes[i] = &ffi_type_uint64;
+                vals8[i] = (uint64_t)SCM_INT_VALUE(value);
+                c_avalues[i] = &vals8[i];
+                break;
+                //case 9: c_atypes[i] = &ffi_type_schar; arg = sexp_sint_value(avalues[i]); break;
+                //case 10: c_atypes[i] = &ffi_type_uchar; arg = sexp_uint_value(avalues[i]); break;
+                //case 11: c_atypes[i] = &ffi_type_sshort; arg = sexp_sint_value(avalues[i]); break;
+                //case 12: c_atypes[i] = &ffi_type_ushort; arg = sexp_uint_value(avalues[i]); break;
+            case 13:
+                c_atypes[i] = &ffi_type_sint;
+                vals13[i] = (int)SCM_INT_VALUE(value);
+                c_avalues[i] = &vals13[i];
+                break;
+                //case 14: c_atypes[i] = &ffi_type_uint; arg = sexp_uint_value(avalues[i]); break;
+                //case 15: c_atypes[i] = &ffi_type_slong; arg = sexp_sint_value(avalues[i]); break;
+                //case 16: c_atypes[i] = &ffi_type_ulong; arg = sexp_uint_value(avalues[i]); break;
+                // FIXME
+                //case 17: c_atypes[i] = &ffi_type_float; arg = sexp_flonum_value(avalues[i]); break;
+                // FIXME
+                //case 18: c_atypes[i] = &ffi_type_double; arg = sexp_flonum_value(avalues[i]); break;
+                //case 19: c_atypes[i] = &ffi_type_void; arg = NULL; break;
+            case 20:
+                //printf("Argument value: %s\n", SCM_FOREIGN_POINTER_REF(char*, value));
+                c_atypes[i] = &ffi_type_pointer;
+                vals20[i] = SCM_FOREIGN_POINTER_REF(void*, value);
+                c_avalues[i] = &vals20[i];
+                //printf("Argument value1: %s\n", *(char**)c_avalues[i]);
+                //printf("Pointer value: %s\n", sexp_cpointer_maybe_null_value(avalues[i]));
+                break;
+            default:
+                //printf("Undefined argument type: %i, index: %i\n", SCM_INT_VALUE(type), i);
+                //c_avalues[i] = sexp_cpointer_value(avalues[i]);
+                break;
+        }
+    }
+
+    ffi_type* c_rtype = &ffi_type_void;
+    switch(SCM_INT_VALUE(rtype)) {
+      case 1: c_rtype = &ffi_type_sint8; break;
+      case 2: c_rtype = &ffi_type_uint8; break;
+      case 3: c_rtype = &ffi_type_sint16; break;
+      case 4: c_rtype = &ffi_type_uint16; break;
+      case 5: c_rtype = &ffi_type_sint32; break;
+      case 6: c_rtype = &ffi_type_uint32; break;
+      case 7: c_rtype = &ffi_type_sint64; break;
+      case 8: c_rtype = &ffi_type_uint64; break;
+      case 9: c_rtype = &ffi_type_schar; break;
+      case 10: c_rtype = &ffi_type_uchar; break;
+      case 11: c_rtype = &ffi_type_sshort; break;
+      case 12: c_rtype = &ffi_type_ushort; break;
+      case 13: c_rtype = &ffi_type_sint; break;
+      case 14: c_rtype = &ffi_type_uint; break;
+      case 15: c_rtype = &ffi_type_slong; break;
+      case 16: c_rtype = &ffi_type_ulong; break;
+      case 17: c_rtype = &ffi_type_float; break;
+      case 18: c_rtype = &ffi_type_double; break;
+      case 19: c_rtype = &ffi_type_void; break;
+      case 20: c_rtype = &ffi_type_pointer; break;
+      default:
+        printf("Undefined return type: %i\n", SCM_INT_VALUE(rtype));
+        c_rtype = &ffi_type_pointer;
+      break;
+    }
+
+    int prep_status = ffi_prep_cif(&cif, FFI_DEFAULT_ABI, c_nargs, c_rtype, c_atypes);
+
+    void* c_fn = SCM_FOREIGN_POINTER_REF(void*, fn);
+    void* rvalue = malloc(SCM_INT_VALUE(rvalue_size)); //SCM_FOREIGN_POINTER_REF(void*, rvalue);
+    /*
+    int avalues_length = (int)Scm_Length(avalues);
+    void* c_avalues[avalues_length];
+    for(int i = 0; i < avalues_length; i++) {
+        ScmObj item = Scm_ListRef(avalues, i, SCM_UNDEFINED);
+        void* pp = SCM_FOREIGN_POINTER_REF(void*, item);
+        char* list_p = (char*)c_avalues + (sizeof(void) * i);
+        c_avalues[i] = pp;
+    }*/
+    ffi_call(&cif, FFI_FN(c_fn), rvalue, c_avalues);
+
+    //printf("Return value: %s\n", (char*)rvalue);
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "pointer", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, rvalue);
+}
+
+ScmObj scheme_procedure_to_pointer(ScmObj procedure) {
+    ScmClass* pointer_class = Scm_MakeForeignPointerClass(module, "callback", print_pointer, NULL, 0);
+    return Scm_MakeForeignPointer(pointer_class, procedure);
+}
+
+/*
+ScmObj procedure_to_pointer(ScmObj procedure) {
+
+    return SCM_UNDEFINED;
+}*/
+
+void Scm_Init_gauche(void)
+{
+    SCM_INIT_EXTENSION(foreign.c.primitives.gauche);
+    module = SCM_MODULE(SCM_FIND_MODULE("foreign.c.primitives.gauche", TRUE));
+    Scm_Init_gauchelib();
+}