GDB Skip Directories

2015 Jul 25

So I've been wanting to ignore STL, Boost, et al (collectively '3rd Party') files when debugging for a while. Yesterday I finally decided to look for a solution and it seems the nearest capability is the 'skip' command in GDB.

I found the 'skip' feature in GDB (as of gdb 7.4) to be helpful, but it's still a nuisance for me because my program uses a lot of STL and other "3rd Party" template code. In this case I have to mark a bunch of files as skip. After the 2nd time doing so I realized it would be more helpful to be able to skip an entire directory--and most helpful to skip a directory and all subdirectories. That way I can skip, for example, /usr since none of my code lives there and I typically have no interest in debugging through 3rd party code. So I extended the 'skip' command in gdb to support a new subcommand: 'dir'.

Usage is:
skip dir [directory]
If the directory is not specified, the directory of the current file is used. With this command, all files in the directory or any subdirectory will be skipped when stepping in GDB.

So upon starting gdb I issue:
skip dir /usr
and then I'm never stopped in any of my 3rd party headers.

Caveats:

• I consider the code change moderately quick-and-dirty right now, especially since it piggy-backs on the 'skip file' mech and doesn't use all of gdb's internal functions (ex. malloc).
  That's the main reason why I don't just put this for inclusion in the main tree.
• I don't know if this works when system headers are included automatically by gcc, or if they're included w/ a relative path. My build system is setup to specify absolute paths for all include paths including the system ones and it works, but that's not typical.
• I've only verified this on a few linux systems (Gentoo, Ubuntu, CentOS).

Time permitting I hope to submit a suitable patch for inclusion in GDB mainline, but that's likely not anytime soon. If anyone wants to take it forward, please do.

Send questions to [[gdb AT codesniffer DOT com]], but understand that I may not have time for investigations.

Here are the patches:

• 2015-07-25: GDB 7.4: gdb-7.4_skip_dir_2015-07-25.patch
• 2018-12-26: GDB 8.2: gdb-8.2_skip_dir_2018-12-26.patch

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