Hi.
I compiled mod_jk (Tomcat 3.2.1) on a OSF1 alpha 5.1 (Compaq Tru64) using
the Compaq cc, but got this warning that scares me a lot
cc: Warning: ../jk/jk_msg_buff.c, line 88: In this statement, the expression
"printf(...)" modifies the variable "i" more than once without an
intervening sequence point. This behavior is undefined. (undefvarmod)
printf("%s %d/%d/%d %x %x %x %x - %x %x %x %x - %x %x %x %x - %x %x
%x %x\n", err, msg->pos, msg->len, msg->maxlen,
so i tried to compile this little c program
#include <stdio.h>
int main()
{
unsigned int i = 0;
printf("%x %x %x\n", i++, i++, i++);
return 0;
}
on a few platforms. Here are the results
Compaq cc on osf1 tru64 5.1 alpha: 0 0 0 (with the above mentioned compiler
warning)
GCC on the above: 0 1 2
GCC on Linux i386: 2 1 0
SGI cc on Irix 6.2 (good old beast): 0 0 0
Microsoft Visual C++ 6.0 on win2k: 0 0 0
This is the suspect code from jk_msg_buff.c
/*
* Simple marshaling code.
*/
/* XXX what's above this line can go to .h XXX */
void jk_b_dump(jk_msg_buf_t *msg, char *err)
{
int i=0;
printf("%s %d/%d/%d %x %x %x %x - %x %x %x %x - %x %x %x %x - %x %x
%x %x\n", err, msg->pos, msg->len, msg->maxlen,
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++],
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++],
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++],
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++]);
i = msg->pos - 4;
if(i < 0) {
i=0;
}
printf(" %x %x %x %x - %x %x %x %x --- %x %x %x %x - %x %x %x
%x\n",
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++],
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++],
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++],
msg->buf[i++],msg->buf[i++],msg->buf[i++],msg->buf[i++]);
}
What's the purpose of this function? Can I get along with this odd
behaviour? TIA.
Regards,
\mirko
