Ticket #376: setjump.d

module setjump;
// setjmp.c
//
// Non-local goto
//
// Copyright (C) 2002 Michael Ringgaard. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 
// 1. Redistributions of source code must retain the above copyright 
//    notice, this list of conditions and the following disclaimer.  
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.  
// 3. Neither the name of the project nor the names of its contributors
//    may be used to endorse or promote products derived from this software
//    without specific prior written permission. 
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
// SUCH DAMAGE.
// 

 struct jmp_buf 
{
  ulong ebp;
  ulong ebx;
  ulong edi;
  ulong esi;
  ulong esp;
  ulong eip;
} 


const OFS_EBP=   0;
const OFS_EBX=   4;
const OFS_EDI=   8;
const OFS_ESI=   12;
const OFS_ESP=   16;
const OFS_EIP=   20;
extern (C)
{
int setjmp(ref jmp_buf env)
{
  asm
  {
    naked;
    mov EDX, 4[ESP] ;         // Get jmp_buf pointer
    mov EAX, [ESP] ;          // Save EIP
    mov OFS_EIP[EDX], EAX;
    mov OFS_EBP[EDX], EBP;    // Save EBP, EBX, EDI, ESI, and ESP
    mov OFS_EBX[EDX], EBX;
    mov OFS_EDI[EDX], EDI;
    mov OFS_ESI[EDX], ESI;
    mov OFS_ESP[EDX], ESP;
    add ESP,8;
    push EAX; 
    xor EAX, EAX;             // Return 0
    ret;
  };
}

 void longjmp(ref jmp_buf env, int value)
{
 asm
  {
     naked ;
    mov EDX, 4[ESP] ;         // Get jmp_buf pointer
    mov EAX, 8[ESP] ;         // Get return value (eax)

    mov ESP, OFS_ESP[EDX];    // Switch to new stack position
    mov EBX, OFS_EIP[EDX];    // Get new EIP value and set as return address
    mov [ESP], EBX;
    
    mov EBP, OFS_EBP[EDX];    // Restore EBP, EBX, EDI, and ESI
    mov EBX, OFS_EBX[EDX];
    mov EDI, OFS_EDI[EDX];
    mov ESI, OFS_ESI[EDX];

    ret;
  };
  }
}