trq@MOOSE.CITA.UTORONTO.CA (Tom Quinn) (01/17/89)
gcc with the "-O -fomit-frame-pointer" flags compiles the following
code into something which loses track of the stack pointer, and
therefore, returns to never-neverland. This is gcc version 1.32 on a
Sun 3/50 running SunOS 3.5.
Tom Quinn Canadian Institute for Theoretical Astrophysics
trq@moose.cita.utoronto.ca
UUCP - decvax!utgpu!moose!trq
BITNET - quinn@utorphys.bitnet
ARPA - trq%moose.cita.toronto.edu@relay.cs.net
The compile:
gcc -S -g -v -O -fomit-frame-pointer -c history.c
gcc version 1.32
/usr/local/lib/gcc-cpp -v -undef -D__GNUC__ -Dmc68000 -Dsun -Dunix -D__mc68000_
_ -D__sun__ -D__unix__ -D__OPTIMIZE__ -D__HAVE_68881__ -Dmc68020 history.c /tmp/cca28687.cpp
GNU CPP version 1.32
/usr/local/lib/gcc-cc1 /tmp/cca28687.cpp -quiet -dumpbase history.c -fomit-frame-pointer -g -O -version -o history.s
GNU C version 1.32 (68k, MIT syntax) compiled by GNU C version 1.32.
The offending assembler:
.stabd 68,0,31
clrl sp@-
movel a2,sp@-
jbsr _edit_line
movel d0,d1
moveq #14,d3
cmpl d1,d3
jeq L15
jlt L25
moveq #13,d3
cmpl d1,d3
jeq L6
addqw #8,sp ### this should be before the above jumps.
jra L21
L25:
moveq #16,d3
cmpl d1,d3
jeq L17
jra L21
The code:
------------------------------------------------------------------------
extern struct _iobuf {
int _cnt;
unsigned char *_ptr;
unsigned char *_base;
int _bufsiz;
short _flag;
char _file;
} _iob[];
extern char _ctype_[];
typedef struct {
char line[82 ];
int num;
} HISTORY;
static char search_str[40] = "";
static HISTORY **hist;
extern int interrupt;
static int hindex,
hlev,
hsize;
char *
edit_hist()
{
char *current,
*strcpy(),
*strncpy();
int i,
index = 0;
current = hist[hindex%hsize]->line;
erase_str(current,82 );
for(;;) {
switch(i = edit_line(current,(char **)0 )) {
case 13 :
interrupt = 0;
search_str[0] = '\0';
printf("\n");
for(i = strlen(current) - 1;i >= 0 && current[i] != '\0';i--) {
if(!((_ctype_+1)[current[i]]&010 ) ) break;
current[i] = '\0';
}
if(i < 0) {
break;
}
if(hindex == 0 || strcmp(hist[hindex%hsize]->line,
hist[(hindex - 1)%hsize]->line) != 0) {
hist[hindex++%hsize]->num = hlev++;
}
return(current);
case 14 :
if(index > 0) {
index--;
}
erase_str(current,82 );
(void)strcpy(current,hist[(hsize + hindex - index)%hsize]->line);
break;
case 16 :
if(index <= hsize - 1 &&
(index == 0 || hist[(hsize + hindex - index)%hsize]->num > 0)) {
index++;
}
erase_str(current,82 );
if(hist[(hsize + hindex - index)%hsize]->num > 0) {
(void)strcpy(current,hist[(hsize + hindex - index)%hsize]->line);
}
break;
default:
(--((&_iob[1]) )->_cnt>=0? (int)(*((&_iob[1]) )->_ptr++=(unsigned char)((7 ))):_flsbuf((unsigned char)((7 )),(&_iob[1]) )) ;
break;
}
(void)fflush((&_iob[1]) );
}
}trq@MOOSE.CITA.UTORONTO.CA (Tom Quinn) (01/20/89)
The following code generates incorrect assembly when compiled with the
"-g -O -fforce-mem" options. This is gcc version 1.32 on a Sun 3/50
running SunOs 3.5. The problem is that the assignment on line 117
from the long to the short grabs the wrong half of the long.
Tom Quinn Canadian Institute for Theoretical Astrophysics
trq@moose.cita.utoronto.ca
UUCP - decvax!utgpu!moose!trq
BITNET - quinn@utorphys.bitnet
ARPA - trq%moose.cita.toronto.edu@relay.cs.net
The compile:
gcc -S -g -v -O -fforce-mem -c XConnDis.c
gcc version 1.32
/usr/local/lib/gcc-cpp -v -undef -D__GNUC__ -Dmc68000 -Dsun -Dunix -D__mc68000__ -D__sun__ -D__unix__ -D__OPTIMIZE__ -D__HAVE_68881__ -Dmc68020 XConnDis.c /tmp/cca15882.cpp
GNU CPP version 1.32
/usr/local/lib/gcc-cc1 /tmp/cca15882.cpp -quiet -dumpbase XConnDis.c -fforce-mem -g -O -version -o XConnDis.s
GNU C version 1.32 (68k, MIT syntax) compiled by GNU C version 1.32.
The offending assembly:
L20:
.stabd 68,0,117
movew a0@(8),a6@(-272) # this should be a "movew a0(10),a6@(-272)"
.stabd 68,0,120
The code:
------------------------------------------------------------------------
typedef unsigned char u_char;
typedef unsigned short u_short;
typedef unsigned long u_long;
char *strcat();
int strcmp();
char *strcpy();
int strlen();
struct in_addr {
union {
struct { u_char s_b1,s_b2,s_b3,s_b4; } S_un_b;
struct { u_short s_w1,s_w2; } S_un_w;
u_long S_addr;
} S_un;
};
struct sockaddr_in {
short sin_family;
u_short sin_port;
struct in_addr sin_addr;
char sin_zero[8];
};
struct hostent {
char *h_name;
char **h_aliases;
int h_addrtype;
int h_length;
char *h_addr;
};
char *strncpy();
extern char *index();
extern int errno;
struct sockaddr {
u_short sa_family;
char sa_data[14];
};
struct sockaddr_un {
short sun_family;
char sun_path[109];
};
void bcopy();
int _XConnectDisplay (display_name, expanded_name, prop_name, screen_num)
char *display_name;
char *expanded_name;
char *prop_name;
int *screen_num;
{
char displaybuf[256];
register char *display_ptr;
register char *numbuf_ptr;
char *screen_ptr;
int display_num;
struct sockaddr_in inaddr;
unsigned long hostinetaddr;
struct sockaddr_un unaddr;
struct sockaddr *addr;
struct hostent *host_ptr;
int addrlen;
extern char *getenv();
extern struct hostent *gethostbyname();
int fd;
char numberbuf[16];
char *dot_ptr = 0 ;
(void) strncpy(displaybuf, display_name, sizeof(displaybuf));
if ((display_ptr = index((displaybuf), (':')) ) == 0 ) return (-1);
*(display_ptr++) = '\0';
if (*display_ptr == '\0') return(-1);
screen_ptr = display_ptr;
numbuf_ptr = numberbuf;
while (*screen_ptr != '\0') {
if (*screen_ptr == '.') {
if (dot_ptr) {
screen_ptr++;
break;
}
dot_ptr = numbuf_ptr;
*(screen_ptr++) = '\0';
*(numbuf_ptr++) = '.';
} else {
*(numbuf_ptr++) = *(screen_ptr++);
}
}
if (dot_ptr == 0 ) {
dot_ptr = numbuf_ptr;
*(numbuf_ptr++) = '.';
*(numbuf_ptr++) = '0';
} else {
if (*(numbuf_ptr - 1) == '.')
*(numbuf_ptr++) = '0';
}
*numbuf_ptr = '\0';
*screen_num = atoi(dot_ptr + 1);
strcpy (prop_name, screen_ptr);
display_num = atoi(display_ptr);
if (displaybuf[0] == '\0')
;
{
if ((displaybuf[0] == '\0') ||
(strcmp("unix", displaybuf) == 0)) {
unaddr.sun_family = 1 ;
(void) strcpy(unaddr.sun_path, "/tmp/.X11-unix/X" );
strcat(unaddr.sun_path, display_ptr);
addr = (struct sockaddr *) &unaddr;
addrlen = strlen(unaddr.sun_path) + 2;
if ((fd = socket((int) addr->sa_family, 1 , 0)) < 0)
return(-1);
} else
{
hostinetaddr = inet_addr (displaybuf);
if (hostinetaddr == -1) {
if ((host_ptr = gethostbyname(displaybuf)) == 0 ) {
errno = 22 ;
return(-1);
}
if (host_ptr->h_addrtype != 2 ) {
errno = 41 ;
return(-1);
}
inaddr.sin_family = host_ptr->h_addrtype;
bcopy((char *)host_ptr->h_addr,
(char *)&inaddr.sin_addr,
sizeof(inaddr.sin_addr));
} else {
inaddr.sin_addr.S_un.S_addr = hostinetaddr;
inaddr.sin_family = 2 ;
}
addr = (struct sockaddr *) &inaddr;
addrlen = sizeof (struct sockaddr_in);
inaddr.sin_port = display_num;
inaddr.sin_port += 6000 ;
inaddr.sin_port = (inaddr.sin_port) ;
if ((fd = socket((int) addr->sa_family, 1 , 0)) < 0)
return(-1);
{
int mi = 1;
setsockopt (fd, 6 , 0x01 , &mi, sizeof (int));
}
}
if (connect(fd, addr, addrlen) == -1) {
(void) close (fd);
return(-1);
}
}
(void) fcntl(fd, 4 , 00004 );
display_ptr = displaybuf-1;
while (*(++display_ptr) != '\0')
;
*(display_ptr++) = ':';
numbuf_ptr = numberbuf;
while (*numbuf_ptr != '\0')
*(display_ptr++) = *(numbuf_ptr++);
if (prop_name[0] != '\0') {
char *cp;
*(display_ptr++) = '.';
for (cp = prop_name; *cp; cp++) *(display_ptr++) = *cp;
}
*display_ptr = '\0';
(void) strcpy(expanded_name, displaybuf);
return(fd);
}