From 30daae6caf996d6864b7ba36782beae46f1ab1fc Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Tue, 8 Aug 2006 22:18:22 +0000 Subject: [PATCH] * gdb.texinfo (Source Path): Add documentation for new substitute-path commands. --- gdb/doc/ChangeLog | 5 +++ gdb/doc/gdb.texinfo | 102 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 107 insertions(+) diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 3ce14cb26df..e4e8a8a490a 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,8 @@ +2006-08-08 Joel Brobecker + + * gdb.texinfo (Source Path): Add documentation for new + substitute-path commands. + 2006-08-08 Daniel Jacobowitz * gdb.texinfo (Installing GDB): Update menu. Move text to... diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 66c8d0f6146..a8b2b2333c1 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -5033,6 +5033,53 @@ To add other directories, use the @code{directory} command. The search path is used to find both program source files and @value{GDBN} script files (read using the @samp{-command} option and @samp{source} command). +In addition to the source path, @value{GDBN} provides a set of commands +that manage a list of source path substitution rules. A @dfn{substitution +rule} specifies how to rewrite source directories stored in the program's +debug information in case the sources were moved to a different +directory between compilation and debugging. A rule is made of +two strings, the first specifying what needs to be rewritten in +the path, and the second specifying how it should be rewritten. +In @ref{set substitute-path}, we name these two parts @var{from} and +@var{to} respectively. @value{GDBN} does a simple string replacement +of @var{from} with @var{to} at the start of the directory part of the +source file name, and uses that result instead of the original file +name to look up the sources. + +Using the previous example, suppose the @file{foo-1.0} tree has been +moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell +GDB to replace @file{/usr/src} in all source path names with +@file{/mnt/cross}. The first lookup will then be +@file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location +of @file{/usr/src/foo-1.0/lib/foo.c}. To define a source path +substitution rule, use the @code{set substitute-path} command +(@pxref{set substitute-path}). + +To avoid unexpected substitution results, a rule is applied only if the +@var{from} part of the directory name ends at a directory separator. +For instance, a rule substituting @file{/usr/source} into +@file{/mnt/cross} will be applied to @file{/usr/source/foo-1.0} but +not to @file{/usr/sourceware/foo-2.0}. And because the substitution +is applied only at the begining of the directory name, this rule will +not be applied to @file{/root/usr/source/baz.c} either. + +In many cases, you can achieve the same result using the @code{directory} +command. However, @code{set substitute-path} can be more efficient in +the case where the sources are organized in a complex tree with multiple +subdirectories. With the @code{directory} command, you need to add each +subdirectory of your project. If you moved the entire tree while +preserving its internal organization, then @code{set substitute-path} +allows you to direct the debugger to all the sources with one single +command. + +@code{set substitute-path} is also more than just a shortcut command. +The source path is only used if the file at the original location no +longer exists. On the other hand, @code{set substitute-path} modifies +the debugger behavior to look at the rewritten location instead. So, if +for any reason a source file that is not relevant to your executable is +located at the original location, a substitution rule is the only +method available to point GDB at the new location. + @table @code @item directory @var{dirname} @dots{} @item dir @var{dirname} @dots{} @@ -5068,6 +5115,61 @@ Reset the source path to its default value (@samp{$cdir:$cwd} on Unix systems). @item show directories @kindex show directories Print the source path: show which directories it contains. + +@anchor{set substitute-path} +@item set substitute-path @var{from} @var{to} +@kindex set substitute-path +Define a source path substitution rule, and add it at the end of the +current list of existing substitution rules. If a rule with the same +@var{from} was already defined, then the old rule is also deleted. + +For example, if the file @file{/foo/bar/baz.c} was moved to +@file{/mnt/cross/baz.c}, then the command + +@smallexample +(@value{GDBP}) set substitute-path /usr/src /mnt/cross +@end smallexample + +@noindent +will tell @value{GDBN} to replace @samp{/usr/src} with +@samp{/mnt/cross}, which will allow @value{GDBN} to find the file +@file{baz.c} even though it was moved. + +In the case when more than one substitution rule have been defined, +the rules are evaluated one by one in the order where they have been +defined. The first one matching, if any, is selected to perform +the substitution. + +For instance, if we had entered the following commands: + +@smallexample +(@value{GDBP}) set substitute-path /usr/src/include /mnt/include +(@value{GDBP}) set substitute-path /usr/src /mnt/src +@end smallexample + +@noindent +@value{GDBN} would then rewrite @file{/usr/src/include/defs.h} into +@file{/mnt/include/defs.h} by using the first rule. However, it would +use the second rule to rewrite @file{/usr/src/lib/foo.c} into +@file{/mnt/src/lib/foo.c}. + + +@item unset substitute-path [path] +@kindex unset substitute-path +If a path is specified, search the current list of substitution rules +for a rule that would rewrite that path. Delete that rule if found. +A warning is emitted by the debugger if no rule could be found. + +If no path is specified, then all substitution rules are deleted. + +@item show substitute-path [path] +@kindex show substitute-path +If a path is specified, then print the source path substitution rule +which would rewrite that path, if any. + +If no path is specified, then print all existing source path substitution +rules. + @end table If your source path is cluttered with directories that are no longer of -- 2.30.2