GDB Not Skipping Functions without Debug Info
I compiled GDB 7 on a Mac OS X Leopard system. When stepping through a C program, GDB fails to step through 'printf()' statements, which probably don't have associated debug information, and starts printing "Cannot find bounds of current function."
Here's some output:
$ /usr/local/bin/gdb try1
GNU gdb (GDB) 7.1
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin10".
(gdb) list
1 #include <stdio.h>
2 static void display(int i, int *ptr);
3
4 int main(void) {
5 int x = 5;
6 int *xptr = &x;
7 printf("In main():\n");
8 printf(" x is %d and is stored at %p.\n", x, &x);
9 printf(" xptr holds %p and points to %d.\n", xptr, *xptr);
10 display(x, xptr);
(gdb) b 6
Breakpoint 1 at 0x1e8e: file tr开发者_开发问答y1.c, line 6.
(gdb) r
Starting program: /tmp/try1
Breakpoint 1, main () at try1.c:6
6 int *xptr = &x;
(gdb) n
7 printf("In main():\n");
(gdb) n
0x0000300a in ?? ()
(gdb) n
Cannot find bounds of current function
(gdb) n
Cannot find bounds of current function
Any idea what's going on?
Alan
Did you compile with -g to enable debug info?
Here is my session:
epronk@godiva:~$ gdb a.out
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu"...
(gdb) list
1 #include <stdio.h>
2
3 int main(void) {
4 int x = 5;
5 int *xptr = &x;
6 printf("In main():\n");
7 printf(" x is %d and is stored at %p.\n", x, &x);
8 printf(" xptr holds %p and points to %d.\n", xptr, *xptr);
9 return 0;
10 }
(gdb) b 6
Breakpoint 1 at 0x400533: file d.c, line 6.
(gdb) r
Starting program: /home/epronk/a.out
Breakpoint 1, main () at d.c:6
6 printf("In main():\n");
(gdb) n
In main():
7 printf(" x is %d and is stored at %p.\n", x, &x);
(gdb) n
x is 5 and is stored at 0x7fff0f3177c4.
8 printf(" xptr holds %p and points to %d.\n", xptr, *xptr);
(gdb) n
xptr holds 0x7fff0f3177c4 and points to 5.
9 return 0;
(gdb) n
10 }
(gdb)
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