Message-ID:	<342777EA.1EFB@xs4all.nl>
Date:	Tue, 23 Sep 1997 10:03:54 +0200
From:	"GRANULAB international B.V." <granulab AT xs4all DOT nl>
MIME-Version:	1.0
To:	djgpp AT delorie DOT com
CC:	rgorkink AT freemail DOT nl
Subject:	Bug in sprintf if with optimalisation (-O3)

Can anyone help me with this problem:

When I compile my program as follow:
	gcc -Wall program.c -o program.exe
the programs will run in a dos box (WIN 95) and also under
MS-dos 7.0.

But when I compile with:
	gcc -O3 -Wall program.c -o program.exe
The program runs also fine under a dos box in Win95, but under
MS-dos 7.0 (NOT a dos box in Win95) I got the next error code:


C:\RICHARD\GUI\bic\BIN>type error.txt
Exiting due to signal SIGSEGV
Page fault at eip=00037da1, error=0006
eax=7ffffffd ebx=00000002 ecx=00000002 edx=00000031 esi=0009034e
edi=00000003
ebp=0008ef84 esp=0008ef78 cs=00e7 ds=00ef es=00ef fs=00ff gs=00ff
ss=00ef
Call frame traceback EIPs:
  0x00037da1   ___dj_movedata+37
  0x00033dd3   __doprnt+2367
  0x0002dd82   _sprintf+42
  0x0000855c   _start_1+7632
  0x000113f4   _start_session+288
  0x000022aa   _callback+54
  0x00004909   _xv_main_loop+2573
  0x0000bfa1   _main+4501
  0x0002c53f   ___crt1_startup+115

C:\RICHARD\GUI\bic\BIN>symify bic.exe

Thus the program crashes when the function sprintf is called.

The part of the source code where this happend is:
    #include <stdio.h>	
    #include <grx20.h>
	
    struct tijd{
	int uur;
	int minuut;
	int seconde;
    }
 
    char *dumtxt[10];
    tijd abs;
    int c_edit=0x07, c_normal=0x05;  
    ...
    ...
    sprintf(*dumtxt,"%02d:%02d:%02d",abs.uur,abs.minuut,abs.seconde);
    GrTextXY(GrMaxX()/2-25,25,*dumtxt,c_edit,c_normal);
    ... 
    ...
	

Thus under the next cirumstances the function sprintf will crash:
  Running in a DOS environment, compiled with -O3.

My questions are, why does it not crash in a dos-box (win95) and why
does it crash at all???

Thanks,

R. Gorkink
Granulab Project B.V.
Amersfoort - The Netherlands

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