Debugging with GDB Manual (5900-1473; WDB 6.2; January 2011)

reverse-search regexp The command 'reverse-search regexp' checks
each line, starting with the one before the last line
listed and going backward, for a match for the
regexp. It lists the line(s) that is found. You can
abbreviate this command as rev.
7.3 Specifying source directories
Executable programs sometimes do not record the directories of the source files from
which they were compiled. Even when they do, the directories can be moved between
the compilation and your debugging session. GDB has a list of directories to search for
source files; this is called the source path. Each time GDB looks for a source file, it tries
all the directories in the list, in the order they are present in the list, until it finds a file
with the desired name. Note that the executable search path is not used for this purpose.
Neither is the current working directory, unless it happens to be in the source path.
If GDB cannot find a source file in the source path, and the object program records a
directory, GDB tries that directory too. If the source path is empty, and there is no record
of the compilation directory, GDB looks in the current directory as a last resort.
Whenever you reset or rearrange the source path, GDB clears out any information it has
cached about where the source files are located and where each line is in the respective
file.
When you start GDB, its source path includes only 'cdir' and 'cwd', in that order.
To add other directories, you can use the directory command.
directory dirname ...,
dir dirname ...
Add directory dirname to the front of the source path.
Several directory names may be given to this
command, separated by ':' (';' on MS-DOS and
MS-Windows, where ':' usually appears as part of
absolute file names) or a whitespace. You can specify
a directory that is already in the source path; this
moves it forward, so GDB searches it sooner.
You can use the string '$cdir' to refer to the
compilation directory (if one is recorded), and '$cwd'
to refer to the current working directory. '$cwd' is not
the same as '.'. The former tracks the current working
directory as it changes during your GDB session, while
the latter is immediately expanded to the current
directory at the time you add an entry to the source
path.
directory Reset the source path to empty again. This requires
confirmation from the user.
7.3 Specifying source directories 73