[4435] in Athena Bugs
vax 6.4R: dbx
daemon@ATHENA.MIT.EDU (ellis@ATHENA.MIT.EDU)
Tue Mar 6 18:10:07 1990
From: ellis@ATHENA.MIT.EDU
To: bugs@ATHENA.MIT.EDU
Date: Tue, 06 Mar 90 18:09:42 EST
System name: E40-369-2
Type and version: CVAXSTAR 6.4R
Display type: SM
What were you trying to do?
examine the contents of an array in a fortran program using the
"trace" command in dbx
What's wrong:
The "trace" command in dbx causes dbx to get a bus error,seg violation
and/or internal error when trying to trace entire array. Error varies
with program and array being examined.
What should have happened:
Each time array element changes, trace should print array.
The following f77 program demonstrates this problem. To duplicate:
a. compile with "f77 -g test.f"
b. run "dbx a.out"
c. In dbx, type "trace a" then "run"
c
c Cut here for test f77 program
c
program test
C
C
dimension a(30,10)
write(6,*) "calling test"
call test1(a,5,5)
do 10 j = 1,10
do 20 i = 1,30
if ( i .eq. j ) then
a(i, j) = 0.0
endif
20 continue
10 continue
C
stop
end
subroutine test1(a,n,m)
dimension a(n,m)
do 10 j = 1,m
do 20 i = 1,n
a(i,j) = float(i) + float(j)
20 continue
10 continue
return
end
The following C program, when compiled demonstrates expected behavior.
/* Sample C program for trace test in dbx */
static float a[5][5];
main()
{
printf("start work");
test1(&a);
printf ("Cease work");
}
test1(b)
float b[5][5];
{
int i,j;
for(i=0;i < 5; i++) {
for(j=0;j < 5; j++) {
b[i][j] = i + j;
}
}
}
