🚀 go-pugleaf

i've run into the following bizarre behavior with gcc 2.2.2 and
dbx on a sparcstation running sunos 4.1.1B and 4.1.2.

when i install breakpoints in loops with dbx and then step through
them, dbx reports that the address/process is no longer writeable. 

this worked with gcc 1.39, same hardware and operating system.

is this a bug with dbx that's being massaged by gcc, or is it truly
a problem with the code generated by gcc?  

i'd appreciate responses sent directly to me, as i can't read this
group as often as i'd like.

email: Sam.McCall@ucdavis.edu

------------- typescript follows --------------
Script started on Fri Oct  9 13:20:12 1992
chip% ls
./          ../         t.c         typescript
chip% gcc -v -g -o t t.c
Reading specs from /usr/pkg/gnu/lib/gcc-lib/sparc-sun-sunos4.1/2.2.2/specs
gcc version 2.2.2
 /usr/pkg/gnu/lib/gcc-lib/sparc-sun-sunos4.1/2.2.2/cpp -lang-c -v -undef -D__GNUC__=2 -Dsparc -Dsun -Dunix -D__sparc__ -D__sun__ -D__unix__ -D__sparc -D__sun -D__unix -g t.c /usr/tmp/cca11655.i
GNU CPP version 2.2.2 (sparc)
 /usr/pkg/gnu/lib/gcc-lib/sparc-sun-sunos4.1/2.2.2/cc1 /usr/tmp/cca11655.i -quiet -dumpbase t.c -g -version -o /usr/tmp/cca11655.s
GNU C version 2.2.2 (sparc) compiled by GNU C version 2.2.2.
 as -o t.o /usr/tmp/cca11655.s
 /usr/pkg/gnu/lib/gcc-lib/sparc-sun-sunos4.1/2.2.2/ld -e start -dc -dp -o t /lib/crt0.o -L/usr/pkg/gnu/lib/gcc-lib/sparc-sun-sunos4.1/2.2.2 -L/usr/pkg/gnu/lib t.o -lgcc -lc -lg -lgcc
chip% dbx t
Reading symbolic information...
Read 117 symbols
(dbx) list
    6   {
    7           long    v[100];
    8           int     i;
    9   
   10           for(i=0;i<100;i++)
   11                   v[i]=(long)i*i;
   12           for(i=100;i;i--)
   13                   printf("v[%d] is %ld\n",i);
   14   }
(dbx) stop at 10
(2) stop at "/home1/ccsam/tmp/t.c":10
(dbx) run
Running: t 
stopped in main at line 10 in file "t.c"
   10           for(i=0;i<100;i++)
(dbx) step
stopped in main at line 11 in file "t.c"
   11                   v[i]=(long)i*i;
(dbx) step
stopped in main at line 10 in file "t.c"
   10           for(i=0;i<100;i++)
(dbx) step
can't write to process (address 0x10022b8)
May be unwriteable address, unwriteable process, etc (see ptrace(2))
(dbx) quit
chip% dbx t
Reading symbolic information...
Read 117 symbols
(dbx) stop at 13
(2) stop at "/home1/ccsam/tmp/t.c":13
(dbx) run
Running: t 
stopped in main at line 13 in file "t.c"
   13                   printf("v[%d] is %ld\n",i);
(dbx) step
v[100] is 0
stopped in main at line 12 in file "t.c"
   12           for(i=100;i;i--)
(dbx) step
can't write to process (address 0x1002304)
May be unwriteable address, unwriteable process, etc (see ptrace(2))
(dbx) quit
chip% cat t.c
#include <stdio.h>

main(ac,av)
int     ac;
char    **av;
{
        long    v[100];
        int     i;

        for(i=0;i<100;i++)
                v[i]=(long)i*i;
        for(i=100;i;i--)
                printf("v[%d] is %ld\n",i);
}
chip%
script done on Fri Oct  9 13:21:16 1992