FFI callback 準備 - 実行可能属性メモリ

mosh 
    /*
    int return3()
    {
        return 3;
    }
    */
#ifdef ARCH_IA32
    ASSERT_TRUE(mem.push(0x55)); // push   %ebp
    ASSERT_TRUE(mem.push(0x89)); // mov    %esp,%ebp
    ASSERT_TRUE(mem.push(0xe5));
    ASSERT_TRUE(mem.push(0x83)); // sub    $0x8,%esp
    ASSERT_TRUE(mem.push(0xec));
    ASSERT_TRUE(mem.push(0x08));
    ASSERT_TRUE(mem.push(0xb8)); // mov    $0x3,%eax
    ASSERT_TRUE(mem.push(0x03));
    ASSERT_TRUE(mem.push(0x00));
    ASSERT_TRUE(mem.push(0x00));
    ASSERT_TRUE(mem.push(0x00));
    ASSERT_TRUE(mem.push(0xc9)); // leave
    ASSERT_TRUE(mem.push(0xc3)); // ret
#else
    ASSERT_TRUE(mem.push(0x55)); // push   %rbp
    ASSERT_TRUE(mem.push(0x48)); // mov    %rsp,%rbp
    ASSERT_TRUE(mem.push(0x89));
    ASSERT_TRUE(mem.push(0xe5));
    ASSERT_TRUE(mem.push(0xb8)); // mov    $0x3,%eax
    ASSERT_TRUE(mem.push(0x03));
    ASSERT_TRUE(mem.push(0x00));
    ASSERT_TRUE(mem.push(0x00));
    ASSERT_TRUE(mem.push(0x00));
    ASSERT_TRUE(mem.push(0xc9)); // leaveq
    ASSERT_TRUE(mem.push(0xc3)); // retq
#endif

    int (*return3) () = (int (*) ())mem.address();
    EXPECT_EQ(3, return3());