gdb: sim: handle target sysroot prefix

  The default gdb sysroot now sets itself to "target:".  This works for
most remote targets, but when using the simulator, this causes problems
as the sim will attempt to search for that path.

Update the remote-sim logic to skip this leading prefix when it is found
so that the sysroot isn't passed in as an invalid value.

2015-06-21  Mike Frysinger  <vapier@gentoo.org>

	* remote-sim.c: Include gdb_bfd.h.
	(gdbsim_open): Declare new local sysroot pointing to gdb_sysroot.
	Skip TARGET_SYSROOT_PREFIX in gdb_sysroot when it is set.
---
 gdb/remote-sim.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
  

Hi Mike,

Mike Frysinger wrote:
> The default gdb sysroot now sets itself to "target:".  This works
> for most remote targets, but when using the simulator, this causes
> problems as the sim will attempt to search for that path.
> 
> Update the remote-sim logic to skip this leading prefix when it is
> found so that the sysroot isn't passed in as an invalid value.
> 
> 2015-06-21  Mike Frysinger  <vapier@gentoo.org>
> 
> 	* remote-sim.c: Include gdb_bfd.h.
> 	(gdbsim_open): Declare new local sysroot pointing to gdb_sysroot.
> 	Skip TARGET_SYSROOT_PREFIX in gdb_sysroot when it is set.
> ---
>  gdb/remote-sim.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/remote-sim.c b/gdb/remote-sim.c
> index fd2fd58..b4f25bf 100644
> --- a/gdb/remote-sim.c
> +++ b/gdb/remote-sim.c
> @@ -21,6 +21,7 @@
>     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
>  
>  #include "defs.h"
> +#include "gdb_bfd.h"
>  #include "inferior.h"
>  #include "infrun.h"
>  #include "value.h"
> @@ -669,6 +670,7 @@ gdbsim_open (const char *args, int from_tty)
>    int len;
>    char *arg_buf;
>    struct sim_inferior_data *sim_data;
> +  const char *sysroot = gdb_sysroot;
>    SIM_DESC gdbsim_desc;
>  
>    if (remote_debug)
> @@ -715,7 +717,9 @@ gdbsim_open (const char *args, int from_tty)
>      }
>    /* Pass along gdb's concept of the sysroot.  */
>    strcat (arg_buf, " --sysroot=");
> -  strcat (arg_buf, gdb_sysroot);
> +  if (startswith (sysroot, TARGET_SYSROOT_PREFIX))
> +    sysroot += strlen (TARGET_SYSROOT_PREFIX);
> +  strcat (arg_buf, sysroot);
>    /* finally, any explicit args */
>    if (args)
>      {

Please use "is_target_filename (sysroot)" rather than startswith.

Please also update the "strlen (gdb_sysroot)" in this function.

Please note that gdb_sysroot can be NULL.

Otherwise looks good to me :)

Cheers,
Gary
  

On 22 Jun 2015 10:50, Gary Benson wrote:
> Mike Frysinger wrote:
> > @@ -715,7 +717,9 @@ gdbsim_open (const char *args, int from_tty)
> >      }
> >    /* Pass along gdb's concept of the sysroot.  */
> >    strcat (arg_buf, " --sysroot=");
> > -  strcat (arg_buf, gdb_sysroot);
> > +  if (startswith (sysroot, TARGET_SYSROOT_PREFIX))
> > +    sysroot += strlen (TARGET_SYSROOT_PREFIX);
> > +  strcat (arg_buf, sysroot);
> >    /* finally, any explicit args */
> >    if (args)
> >      {
> 
> Please use "is_target_filename (sysroot)" rather than startswith.

OK

> Please also update the "strlen (gdb_sysroot)" in this function.

OK

> Please note that gdb_sysroot can be NULL.

how so ?  main.c:captured_main specifically handles that:

  /* Set the sysroot path.  */
  gdb_sysroot = relocate_gdb_directory (TARGET_SYSTEM_ROOT,
                    TARGET_SYSTEM_ROOT_RELOCATABLE);

  if (gdb_sysroot == NULL || *gdb_sysroot == '\0')
    {
      xfree (gdb_sysroot);
      gdb_sysroot = xstrdup (TARGET_SYSROOT_PREFIX);
    }
-mike
  

Mike Frysinger wrote:
> On 22 Jun 2015 10:50, Gary Benson wrote:
> > Please note that gdb_sysroot can be NULL.
> 
> how so ?  main.c:captured_main specifically handles that:
> 
>   /* Set the sysroot path.  */
>   gdb_sysroot = relocate_gdb_directory (TARGET_SYSTEM_ROOT,
>                     TARGET_SYSTEM_ROOT_RELOCATABLE);
> 
>   if (gdb_sysroot == NULL || *gdb_sysroot == '\0')
>     {
>       xfree (gdb_sysroot);
>       gdb_sysroot = xstrdup (TARGET_SYSROOT_PREFIX);
>     }

Good point.  I may go and clear out all the gdb_sysroot == NULL
checks.

Cheers,
Gary