[Bug c++/17970] cannot call any function or method with "print" or "call" after command "handle SIGSEGV noprint pass"

["palves at redhat dot com" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=17970

Pedro Alves <palves at redhat dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |palves at redhat dot com

--- Comment #8 from Pedro Alves <palves at redhat dot com> ---
That's how it's documented, actually.

The manual says (though that can always be improved):

~~~
 stop
 GDB should stop your program when this signal happens.  This implies
 print keyword as well.

 noprint
 GDB should not mention the occurrence of the signal at all.  This
 implies the nostop keyword as well.
~~~

And you can see that in the "handle" command's output:

 (gdb) handle SIGSEGV
 Signal        Stop      Print   Pass to program Description
 SIGSEGV       Yes       Yes     Yes             Segmentation fault
               ^^^^
 (gdb) handle SIGSEGV noprint
 Signal        Stop      Print   Pass to program Description
 SIGSEGV       No        No      Yes             Segmentation fault
               ^^^^

In here we see that "stop" overrides the "noprint":

 (gdb) handle SIGSEGV noprint stop
 Signal        Stop      Print   Pass to program Description
 SIGSEGV       Yes       Yes     Yes             Segmentation fault
               ^^^^      ^^^^

So AFAIK, there's no way to end up with:

 Signal        Stop      Print   Pass to program Description
 SIGSEGV       Yes       No      Yes             Segmentation fault

I think the intention here is that having GDB silently stop for a signal
would lead to a good deal of head scratching.  More so even if the signal is
set to pass.

There's another way to get that behavior though, using "catch signal" along
with "silent" instead:

 (gdb) catch signal SIGSEGV
 Catchpoint 1 (signal SIGSEGV)
 (gdb) commands 
 >silent
 >end
 (gdb) r
 Starting program: ...
 (gdb) 

(The last prompt appeared because of a SIGSEGV: the program stopped silently)

Though I wonder if you _really_ wanted that behaviour in the first place...

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