[PATCH] Make only user-specified executable filenames sticky

[Pedro Alves]

On 05/06/2015 11:26 AM, Gary Benson wrote:
> Hi all,
> 
> In GDB some executable files are supplied by the user (e.g. using a
> "file" command) and some are determined by GDB (e.g. while processing
> an "attach" command).  GDB will not attempt to determine a filename if
> one has been set.  This causes problems if you attach to one process
> and then attach to another: GDB will not attempt to discover the main
> executable on the second attach.  If the two processes have different
> main executable files then the symbols will now be wrong.
> 
> This commit updates GDB to keep track of which executable filenames
> were supplied by the user.  When GDB might attempt to determine an
> executable filename and one is already set, filenames determined by
> GDB may be overridden but user-supplied filenames will not.

I have a feeling this would be simpler if the flag's sense was
reversed?  That is, mark the exec as auto-discovered instead of
marking it user-loaded.

How does this interact with "symbol-file FILE" ?

> Built and regtested on RHEL6.6 x86_64.
> 
> Is this ok to commit?

This fixes PR 17626 (so please add that to the ChangeLog), which is
marked as duplicate of PR 16266 currently, but in a different way
than 16266 suggests.

 https://sourceware.org/bugzilla/show_bug.cgi?id=16266
 https://sourceware.org/bugzilla/show_bug.cgi?id=17626

I think this needs a NEWS entry, and probably a tweak to the
manual somewhere.

> --- a/gdb/exec.h
> +++ b/gdb/exec.h
> @@ -32,6 +32,8 @@ struct objfile;
>  #define exec_bfd current_program_space->ebfd
>  #define exec_bfd_mtime current_program_space->ebfd_mtime
>  #define exec_filename current_program_space->pspace_exec_filename
> +#define user_supplied_exec_file_p \
> +  current_program_space->pspace_user_supplied_exec_file_p

Nit, but I'd suggest 'exec_file_is_user_supplied', which would
fit the pattern of vars related to the exec being prefixed exec_.

>  
> --- a/gdb/progspace.h
> +++ b/gdb/progspace.h
> @@ -154,6 +154,13 @@ struct program_space
>         It needs to be freed by xfree.  It is not NULL iff EBFD is not NULL.  */
>      char *pspace_exec_filename;
>  
> +    /* Nonzero if pspace_exec_filename was supplied by the user,
> +       either at startup (on the command-line) or via a "file"
> +       an "add-inferior -exec" command.  Zero if

Sounds like an "or" is missing between the commands.

Thanks,
Pedro Alves