Getting GDB to save a list of breakpoints

user_10578 0
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OK, info break lists the breakpoints, but not in a format that would work well with reusing them using the --command as in this question. Does GDB have a method for dumping them into a file acceptable for input again? Sometimes in a debugging session, it is necessary to restart GDB after building up a set of breakpoints for testing.

The .gdbinit file has the same problem as --command. The info break command does not list commands, but rather a table for human consumption.

To elaborate, here is a sample from info break:

(gdb) info break
Num Type           Disp Enb Address    What
1   breakpoint     keep y   0x08048517 <foo::bar(void)+7>
gdb breakpoints c c++ debugging
11 Answers

This answer is outdated. GDB now supports saving directly. See this answer.

You can use logging:

(gdb) b main
Breakpoint 1 at 0x8049329
(gdb) info break
Num     Type           Disp Enb Address    What
1       breakpoint     keep y   0x08049329 <main+16>
(gdb) set logging file breaks.txt
(gdb) set logging on
Copying output to breaks.txt.
(gdb) info break
Num     Type           Disp Enb Address    What
1       breakpoint     keep y   0x08049329 <main+16>
(gdb) q

The file breaks.txt now contains:

Num     Type           Disp Enb Address    What
1       breakpoint     keep y   0x08049329 <main+16>

Writing an AWK script that transforms that into a format useful for the .gdbinit or a --command file is easy. Or you may even make the script emit separate --eval-command's to the GDB command line...

Adding this small macro to .gdbinit will help you do it:

# Call with dump_breaks file.txt
define dump_breaks
    set logging file $arg0
    set logging redirect on
    set logging on
    info breakpoints
    set logging off
    set logging redirect off
end
litb_345090

Put your GDB commands and breakpoints in a .gdbinit file just as you might type them at the gdb> prompt, and GDB will automatically load and run them on startup. This is a per-directory file, so you can have different files for different projects.

user_143560

Extension to the answer from Johannes: you could automatically reformat the output of info break into a valid GDB command file:

.gdbinit:

define bsave
   shell rm -f brestore.txt
   set logging file brestore.txt
   set logging on
   info break
   set logging off
   # Reformat on-the-fly to a valid gdb command file
   shell perl -n -e 'print "break $1\n" if /^\d+.+?(\S+)$/g' brestore.txt > brestore.gdb
end
document bsave
  store actual breakpoints
end

Afterwards you have a valid commandfile in brestore.gdb.

This worked for me when the application is compiled with -g.

I also successfully tested it with GDB v6.8 on Ubuntu 9.10 (Karmic Koala).

Admin1

I found the following addition to a previous answer useful to save/load the breakpoints to a specific file.

  • Save breakpoints: bsave {filename}
  • Load breakpoints: bload {filename}

As in the previous answer, add the following code to the file ~/.gdbinit

# Save breakpoints to a file
define bsave
    if $argc != 1
        help bsave
    else
    save breakpoints $arg0
    end
end
document bsave
Saves all current defined breakpoints to the defined file in the PWD
Usage: bsave <filename>
end

# Loads breakpoints from a file
define bload
    if $argc != 1
        help bload
    else
        source $arg0
    end
end
document bload
Loads all breakpoints from the defined file in the PWD
Usage: bload <filename>
end
user_61547680
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