[binutils-gdb] gdb: remove unnecessary 'dir' commands from gdb-gdb.gdb script

[binutils-gdb] gdb: remove unnecessary 'dir' commands from gdb-gdb.gdb script

[Andrew Burgess]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b9c05fc03d313d8505df2c1265481faf6594b62a

commit b9c05fc03d313d8505df2c1265481faf6594b62a
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Wed Feb 8 16:47:34 2023 +0000

    gdb: remove unnecessary 'dir' commands from gdb-gdb.gdb script
    
    While debugging GDB I used 'show directories' and spotted lots of
    entries that didn't make much sense. Here are all the entries that are
    in my directories list:
    
      /tmp/binutils-gdb/build
      /tmp/binutils-gdb/build/../../src/gdb
      /tmp/binutils-gdb/build/../../src/gdb/../bfd
      /tmp/binutils-gdb/build/../../src/gdb/../libiberty
      $cdir
      $cwd
    
    Notice the second, third, and fourth entries in this list, these
    should really be:
    
      /tmp/binutils-gdb/build/../src/gdb
      /tmp/binutils-gdb/build/../src/gdb/../bfd
      /tmp/binutils-gdb/build/../src/gdb/../libiberty
    
    The problem is because I generally run everything from the top level
    build directory, not the gdb/ sub-directory, thus, I start GDB like:
    
      ./gdb/gdb --data-directory ./gdb/data-directory
    
    If run GDB under GDB, then I end up loading the gdb/gdb-gdb.gdb
    script, which contains these lines:
    
      dir ../../src/gdb/../libiberty
      dir ../../src/gdb/../bfd
      dir ../../src/gdb
      dir .
    
    These commands only make sense when running within the gdb/
    sub-directory.
    
    However, my debugging experience doesn't seem to be degraded at all, I
    can still see the GDB source code just fine; which is because the
    directory list still contains $cdir.
    
    The build/gdb/gdb-gdb.gdb script is created from the
    src/gdb/gdb-gdb.gdb.in template, which includes the automake @srcdir@
    markers.
    
    The 'dir' commands have mostly been around since the sourceware
    repository was first created, though this commit 67f0714670383a did
    reorder some of the 'dir' commands, which would seem to indicate these
    commands were important to some people, at some time.
    
    One possible fix would be to replace @srcdir@ with @abs_srcdir@, this
    would ensure that the entries added were all valid, no matter the
    user's current directory when debugging GDB.
    
    However... I'd like to propose that we instead remove all the extra
    directories completely.  My hope is that, with more recent tools, the
    debug information should allow us to correctly find all of the source
    files without having to add any extra 'dir' entries.  Obviously,
    commit 67f0714670383a does make me a little nervous, but the
    gdb-gdb.gdb script isn't something a non-maintainer will be using, so
    I think we can afford to be a little more aggressive here.  If it
    turns out the 'dir' entries are needed then we can add them back, but
    actually document why they are needed.  Plus, when we add them back we
    will use @abs_srcdir@ instead of @srcdir@.
    
    Reviewed-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/gdb-gdb.gdb.in | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/gdb/gdb-gdb.gdb.in b/gdb/gdb-gdb.gdb.in
index 8d97c95a70e..b9fd457d069 100644
--- a/gdb/gdb-gdb.gdb.in
+++ b/gdb/gdb-gdb.gdb.in
@@ -16,11 +16,6 @@ if !$gdb_init_done
     return
   end
 
-  dir @srcdir@/../libiberty
-  dir @srcdir@/../bfd
-  dir @srcdir@
-  dir .
-
   # Commands below are not fully compatible with wrapping into an 'if' block.
 end