asmutil.h

/*
    Copyright 2020 David "Alemarius Nexus" Lerch
 
    This file is part of RemoteMono.
 
    RemoteMono is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    RemoteMono is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public License
    along with RemoteMono.  If not, see <https://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include "config.h"
 
#include <BlackBone/Process/Process.h>
#include "impl/RMonoTypes.h"
 
 
 
namespace remotemono
{
 
 
 
inline void AsmGenGchandleGetTargetChecked(blackbone::IAsmHelper& a, blackbone::ptr_t rawAddr, bool x64)
{
    // NOTE: Always expects an irmono_gchandle in zcx.
 
    using namespace asmjit;
    using namespace asmjit::host;
 
    auto lSkip = a->newLabel();
 
    static_assert(REMOTEMONO_GCHANDLE_INVALID == 0);
 
    //  zax = nullptr;
        a->xor_(a->zax, a->zax);
 
    //  if (zcx != REMOTEMONO_GCHANDLE_INVALID) {
        a->jecxz(a->zcx, lSkip);
 
    //      zax = mono_gchandle_get_target(zcx);
            a->mov(a->zax, rawAddr);
            if (x64) {
                a->sub(a->zsp, 32);
                a->call(a->zax);
                a->add(a->zsp, 32);
            } else {
                a->push(a->zcx);
                a->call(a->zax);
                a->pop(a->zcx);
            }
 
    //  }
        a->bind(lSkip);
}
 
 
inline void AsmGenGchandleNewChecked(blackbone::IAsmHelper& a, blackbone::ptr_t rawAddr, bool x64)
{
    // NOTE: Always expects an IRMonoObjectPtrRaw in zcx.
 
    using namespace asmjit;
    using namespace asmjit::host;
 
    auto lSkip = a->newLabel();
 
    static_assert(REMOTEMONO_GCHANDLE_INVALID == 0);
 
    //  zax = REMOTEMONO_GCHANDLE_INVALID;
        a->xor_(a->zax, a->zax);
 
    //  if (zcx != nullptr) {
        a->jecxz(a->zcx, lSkip);
 
    //      zax = mono_gchandle_new(zcx, false);
            a->mov(a->zax, rawAddr);
            if (x64) {
                a->xor_(a->zdx, a->zdx); // Don't pin the GCHandle
                a->sub(a->zsp, 32);
                a->call(a->zax);
                a->add(a->zsp, 32);
            } else {
                a->push(0); // Don't pin the GCHandle
                a->push(a->zcx);
                a->call(a->zax);
                a->add(a->zsp, 2*sizeof(uint32_t));
            }
 
    //  }
        a->bind(lSkip);
}
 
 
inline void AsmGenIsValueTypeInstance (
        blackbone::IAsmHelper& a,
        blackbone::ptr_t objectGetClassAddr,
        blackbone::ptr_t classIsValuetypeAddr,
        bool x64
) {
    // bool is_value_type_instance(IRMonoObjectPtrRaw obj)
    //
    //      obj: zcx
 
    using namespace asmjit;
    using namespace asmjit::host;
 
    auto lSkip = a->newLabel();
 
    //  zax = false;
    a->xor_(a->zax, a->zax);
 
    //  if (obj != nullptr) {
        a->jecxz(a->zcx, lSkip);
 
    //      zax = mono_class_is_valuetype(mono_object_get_class(obj));
            if (x64) {
                a->sub(a->zsp, 32);
                a->mov(a->zax, objectGetClassAddr);
                a->call(a->zax);
                a->mov(a->zcx, a->zax);
                a->mov(a->zax, classIsValuetypeAddr);
                a->call(a->zax);
                a->add(a->zsp, 32);
            } else {
                a->push(a->zcx);
                a->mov(a->zax, objectGetClassAddr);
                a->call(a->zax);
                a->mov(ptr(a->zsp), a->zax);
                a->mov(a->zax, classIsValuetypeAddr);
                a->call(a->zax);
                a->add(a->zsp, sizeof(uint32_t));
            }
 
    //  }
        a->bind(lSkip);
}
 
 
inline void AsmGenObjectUnbox (
        blackbone::IAsmHelper& a,
        blackbone::ptr_t objectUnboxAddr,
        bool x64
) {
    // void* object_unbox(IRMonoObjectPtrRaw obj)
    //
    //      obj: zcx
 
    using namespace asmjit;
    using namespace asmjit::host;
 
 
    //  zax = mono_object_unbox(obj);
        if (x64) {
            a->mov(a->zax, objectUnboxAddr);
            a->sub(a->zsp, 32);
            a->call(a->zax);
            a->add(a->zsp, 32);
        } else {
            a->push(a->zcx);
            a->mov(a->zax, objectUnboxAddr);
            a->call(a->zax);
            a->add(a->zsp, sizeof(uint32_t));
        }
}
 
 
 
}