[RFA] Fix crash when command arg is missing in faas/taas/tfaas commands.

  GDB crashes when doing:
  (gdb) faas
  Aborted

Do the needed check to avoid crashing.

gdb/ChangeLog
2019-12-05  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
	* stack.c (faas_command): Check a command is provided.
	* thread.c (taas_command, tfaas_command): Likewise.

gdb/testsuite/ChangeLog
2019-12-05  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* gdb.threads/pthreads.exp: Test taas and tfaas without command.
	* gdb.base/frameapply.exp: Test faas without command.
---
 gdb/stack.c                            | 2 ++
 gdb/testsuite/gdb.base/frameapply.exp  | 2 ++
 gdb/testsuite/gdb.threads/pthreads.exp | 6 +++++-
 gdb/thread.c                           | 4 ++++
 4 files changed, 13 insertions(+), 1 deletion(-)
  

* Philippe Waroquiers <philippe.waroquiers@skynet.be> [2019-12-06 00:05:25 +0100]:

> GDB crashes when doing:
>   (gdb) faas
>   Aborted
> 
> Do the needed check to avoid crashing.
> 
> gdb/ChangeLog
> 2019-12-05  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
> 	* stack.c (faas_command): Check a command is provided.
> 	* thread.c (taas_command, tfaas_command): Likewise.
> 
> gdb/testsuite/ChangeLog
> 2019-12-05  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
> 
> 	* gdb.threads/pthreads.exp: Test taas and tfaas without command.
> 	* gdb.base/frameapply.exp: Test faas without command.

LGTM.

thanks,
Andrew


> ---
>  gdb/stack.c                            | 2 ++
>  gdb/testsuite/gdb.base/frameapply.exp  | 2 ++
>  gdb/testsuite/gdb.threads/pthreads.exp | 6 +++++-
>  gdb/thread.c                           | 4 ++++
>  4 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/stack.c b/gdb/stack.c
> index fcb9cdae03..cc7b7e5bbe 100644
> --- a/gdb/stack.c
> +++ b/gdb/stack.c
> @@ -3281,6 +3281,8 @@ frame_apply_command (const char* cmd, int from_tty)
>  static void
>  faas_command (const char *cmd, int from_tty)
>  {
> +  if (cmd == NULL || *cmd == '\0')
> +    error (_("Please specify a command to apply on all frames"));
>    std::string expanded = std::string ("frame apply all -s ") + cmd;
>    execute_command (expanded.c_str (), from_tty);
>  }
> diff --git a/gdb/testsuite/gdb.base/frameapply.exp b/gdb/testsuite/gdb.base/frameapply.exp
> index ccf30f2079..30314876d1 100644
> --- a/gdb/testsuite/gdb.base/frameapply.exp
> +++ b/gdb/testsuite/gdb.base/frameapply.exp
> @@ -215,3 +215,5 @@ gdb_test "frame apply level 4-2 p 1" "inverted range" "inverted range"
>  gdb_test "frame apply level 0-3" \
>      "Please specify a command to apply on the selected frames" \
>      "missing command"
> +gdb_test "faas" "Please specify a command to apply on all frames" \
> +    "missing command for faas"
> diff --git a/gdb/testsuite/gdb.threads/pthreads.exp b/gdb/testsuite/gdb.threads/pthreads.exp
> index 0bb9083f67..f633b5ec8e 100644
> --- a/gdb/testsuite/gdb.threads/pthreads.exp
> +++ b/gdb/testsuite/gdb.threads/pthreads.exp
> @@ -334,10 +334,14 @@ proc check_qcs {} {
>  	    ] \
>  	"run a failing command except in one frame of thread 2,3, -s to silently continue.  Do not show thread and frame info"
>  
> -    # Check invalid flag combinations.
> +    # Check invalid flag combinations and errors.
>      gdb_test "thread apply all -c -s p 1" \
>  	"thread apply all: -c and -s are mutually exclusive" \
>  	"check -c and -s cannot be used simultaneously"
> +    gdb_test "taas" "Please specify a command to apply on all threads" \
> +	"missing command for taas"
> +    gdb_test "tfaas" "Please specify a command to apply on all frames of all threads" \
> +	"missing command for tfaas"
>  
>  }
>  
> diff --git a/gdb/thread.c b/gdb/thread.c
> index 7c8426d625..a210d328ed 100644
> --- a/gdb/thread.c
> +++ b/gdb/thread.c
> @@ -1818,6 +1818,8 @@ thread_apply_command (const char *tidlist, int from_tty)
>  static void
>  taas_command (const char *cmd, int from_tty)
>  {
> +  if (cmd == NULL || *cmd == '\0')
> +    error (_("Please specify a command to apply on all threads"));
>    std::string expanded = std::string ("thread apply all -s ") + cmd;
>    execute_command (expanded.c_str (), from_tty);
>  }
> @@ -1827,6 +1829,8 @@ taas_command (const char *cmd, int from_tty)
>  static void
>  tfaas_command (const char *cmd, int from_tty)
>  {
> +  if (cmd == NULL || *cmd == '\0')
> +    error (_("Please specify a command to apply on all frames of all threads"));
>    std::string expanded
>      = std::string ("thread apply all -s -- frame apply all -s ") + cmd;
>    execute_command (expanded.c_str (), from_tty);
> -- 
> 2.20.1
>
  

On Thu, 2019-12-05 at 23:08 +0000, Andrew Burgess wrote:
> * Philippe Waroquiers <philippe.waroquiers@skynet.be> [2019-12-06 00:05:25 +0100]:
> 
> > GDB crashes when doing:
> >   (gdb) faas
> >   Aborted
> > 
> > Do the needed check to avoid crashing.
> > 
> > gdb/ChangeLog
> > 2019-12-05  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
> > 	* stack.c (faas_command): Check a command is provided.
> > 	* thread.c (taas_command, tfaas_command): Likewise.
> > 
> > gdb/testsuite/ChangeLog
> > 2019-12-05  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
> > 
> > 	* gdb.threads/pthreads.exp: Test taas and tfaas without command.
> > 	* gdb.base/frameapply.exp: Test faas without command.
> 
> LGTM.
Thanks for the review, pushed.

Philippe