Re: "scheme_setjmp" under Windows DLL?

[Reini Urban <rurban@xarch.tu-graz.ac.at>]

this is only in the debug built of msvc. msvc inserts the esp check in every
function call. in release it should work. at least for me.

On Thu, 8 Mar 2001, Scorzelli Giorgio wrote:

> Hi,
> 
> I'm trying to isolate the MzScheme problem about "scheme_setjmp" 
> instruction which seems not to save correctly the return address if it is 
> invoked in a windows DLL.
> 
> I created a simple DLL library with the following two files (VisualC 
> 6.0/New/DLL/Empty Dll):
> 
> *** DLL.h ***
> --------------------------------------------
>          #ifndef _DLL_H__
>          #define _DLL_H__
> 
>          #ifdef DLL_EXPORTS
>          #define MYEXPORT __declspec(dllexport)
>          #else
>          #define MYEXPORT __declspec(dllimport)
>          #endif
> 
>          MYEXPORT void init();
>          MYEXPORT void eval ();
> 
>          #endif //_DLL_H__
> --------------------------------------------
> 
> 
> 
> *** DLL.cpp ***
> --------------------------------------------
> 
>          #include <scheme.h>
> 
>          #define DLL_EXPORTS
>          #include "dll.h"
> 
>          static Scheme_Env* mySchemeEnv;
> 
> 
>          MYEXPORT void init(){
>                  mySchemeEnv=scheme_basic_env();
>          }
> 
>          MYEXPORT void eval (){
>                  if (scheme_setjmp(scheme_error_buf)){
>                          return;//ERROR!!! HERE IS THE PROBLEM
>                  }else {
>                          Scheme_Object 
> *v=scheme_eval_string("(i-want-error)", mySchemeEnv);
>                  }
>          }
> --------------------------------------------
> 
> 
> and a simple application (Visual C6.0/New/Console application - Make it 
> dependant on the previous DLL):
> 
> *** MAIN.CPP ***
> --------------------------------------------
>          #include "dll.h"
> 
>          int main()
>          {
>                  init();
>                  eval();
>                  return 0;
>          }
> --------------------------------------------
> 
> When I run it it crashes (on DLL "eval" return instruction).
> The debugger warns me about a strange stack condition with the following 
> message:
> 
> --------------------------------------------
> Debug Error!
> Program F:\dll\main.exe
> Module:
> File i386\chkesp.c
> Line: 42
> 
> The value of ESP was not properly saved across a function call.
> This is usually a result of calling a function
> declared with one calling convention with a function pointer declared
> with a different calling convention
> -----------------------------------
> 
> Can someone help me?
> 
> *************************************
> Giorgio Scorzelli
> scr.giorgio@cogesic.it
> http://dia.uniroma3.it/~scorzell
> *************************************
>