Re: [RFC] Apply compilation dir to source_path lookup

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 12 Sep 2019 21:38:51 -0400
> From: Andrew Burgess <andrew.burgess@embecosm.com>
> Cc: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>,
> 	Eli Zaretskii <eliz@gnu.org>
> 
> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index 79824a0226a..b6b87b28b9f 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -8968,9 +8968,23 @@
>  Plain file names, relative file names with leading directories, file
>  names containing dots, etc.@: are all treated as described above; for
>  instance, if the source path is @file{/mnt/cross}, and the source file
> -is recorded as @file{../lib/foo.c}, @value{GDBN} would first try
> -@file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, and after
> -that---@file{/mnt/cross/foo.c}.
> +is recorded as @file{../lib/foo.c} and no compilation directory is
> +recorded, @value{GDBN} would first try @file{../lib/foo.c}, then
> +@file{/mnt/cross/../lib/foo.c}, and after that
> +@file{/mnt/cross/foo.c}.
> +
> +When there is both a filename and a compilation directory in the debug
> +information, and if @value{GDBN} hasn't found the source file using
> +the above approach, then @value{GDBN} will append the filename to the
> +compilation directory and retry using the above steps; for instance,
> +if the source path is @file{/mnt/cross}, and the source file is
> +recorded as @file{../lib/foo.c} and the compilation directory is
> +recorded as @file{/usr/src/foo-1.0/build}, @value{GDBN} would first
> +try @file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, then
> +@file{/mnt/cross/foo.c}, using the approach outlined above.  If the
> +source file still hasn't been found then @value{GDBN} will next check
> +@file{/usr/src/foo-1.0/build/../lib/foo.c}, then
> +@file{/mnt/cross/usr/src/foo-1.0/build/../lib/foo.c}.

This text is unnecessarily long and complicated.  How about this
shortened version -- does it correctly convey the intent?

 Plain file names, relative file names with leading directories, file
 names containing dots, etc.@: are all treated as described above; for
 instance, if the source path is @file{/mnt/cross}, and the source file
 is recorded as @file{../lib/foo.c}, @value{GDBN} would first try
 @file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, and after
 that---@file{/mnt/cross/foo.c}.
 If the above search fails to find the source file @file{foo.c}, and
 the compilation directory is recorded in the debug information,
 @value{GDBN} will repeat the search using the compilation directory
 as if it were in the source path.

>                         @value{GDBN} will also append the compilation
> +directory to the filename and check this against all other entries in
> +the source path.

I think "append" here is a mistake.  Should it be "prepend"?  And
anyway, doesn't this simply repeat what was described in the text
above?

Thanks.