OpenRCT2/test/testpaint/Addresses.cpp

/*****************************************************************************
 * Copyright (c) 2014-2018 OpenRCT2 developers
 *
 * For a complete list of all authors, please refer to contributors.md
 * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
 *
 * OpenRCT2 is licensed under the GNU General Public License version 3.
 *****************************************************************************/

#include "Addresses.h"

#if defined(__GNUC__)
#ifdef __clang__
#define DISABLE_OPT __attribute__((noinline, optnone))
#else
#define DISABLE_OPT __attribute__((noinline, optimize("O0")))
#endif // __clang__
#else
#define DISABLE_OPT
#endif // defined(__GNUC__)

// This variable serves a purpose of identifying a crash if it has happened inside original code.
// When switching to original code, stack frame pointer is modified and prevents breakpad from providing stack trace.
volatile int32_t _originalAddress = 0;

int32_t DISABLE_OPT RCT2_CALLPROC_X(
    int32_t address, int32_t _eax, int32_t _ebx, int32_t _ecx, int32_t _edx, int32_t _esi, int32_t _edi, int32_t _ebp)
{
    int32_t result = 0;
    _originalAddress = address;
#if defined(PLATFORM_X86) && !defined(NO_RCT2)
#ifdef _MSC_VER
    __asm {
        push ebp
        push address
        mov eax, _eax
        mov ebx, _ebx
        mov ecx, _ecx
        mov edx, _edx
        mov esi, _esi
        mov edi, _edi
        mov ebp, _ebp
        call [esp]
        lahf
        pop ebp
        pop ebp
            /* Load result with flags */
        mov result, eax
    }
#else
    __asm__ volatile("\
        \n\
        push %%ebx \n\
        push %%ebp \n\
        push %[address]     \n\
        mov %[eax], %%eax   \n\
        mov %[ebx], %%ebx   \n\
        mov %[ecx], %%ecx   \n\
        mov %[edx], %%edx   \n\
        mov %[esi], %%esi   \n\
        mov %[edi], %%edi   \n\
        mov %[ebp], %%ebp   \n\
        call *(%%esp)   \n\
        lahf \n\
        add $4, %%esp   \n\
        pop %%ebp \n\
        pop %%ebx \n\
        /* Load result with flags */ \n\
        mov %%eax, %[result] \n\
        "
                     : [address] "+m"(address),
                       [eax] "+m"(_eax),
                       [ebx] "+m"(_ebx),
                       [ecx] "+m"(_ecx),
                       [edx] "+m"(_edx),
                       [esi] "+m"(_esi),
                       [edi] "+m"(_edi),
                       [ebp] "+m"(_ebp),
                       [result] "+m"(result)
                     :
                     : "eax", "ecx", "edx", "esi", "edi", "memory");
#endif
#endif // PLATFORM_X86
    _originalAddress = 0;
    // lahf only modifies ah, zero out the rest
    return result & 0xFF00;
}