Re: [PATCH] make gdbhooks.py idempotent with respect to reloading

[Vladislav Ivanishin <vlad at ispras dot ru>]

Vladislav Ivanishin <vlad@ispras.ru> writes:

> Hi!
>
> It is nice to be able to reload the pretty printers and convenience
> functions from gdbhooks.py without exiting GDB: reloading cc1 takes
> several seconds (plus, the debugging session is lost).
>
> Previously:
>
>    (gdb) python import imp; imp.reload(gdbhooks);
>    RuntimeError: pretty-printer already registered: gcc
>
> Fixing this turned out easier than I expected.
>     (gdb) py help (gdb.printing)
> revealed, that we can pass replace parameter to register_pretty_printer
> (which is False by default).
>
> With the patch:
>
>     (gdb) python import imp; imp.reload(gdbhooks);
>     Successfully loaded GDB hooks for GCC
>
> gcc/
>
>         * gdbhooks.py: Pass replace=True to
>         gdb.printing.register_pretty_printer.
> ---
>  gcc/gdbhooks.py | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/gdbhooks.py b/gcc/gdbhooks.py
> index 15a5ceaa56f..26a09749aa3 100644
> --- a/gcc/gdbhooks.py
> +++ b/gcc/gdbhooks.py
> @@ -602,7 +602,8 @@ def build_pretty_printer():
>  
>  gdb.printing.register_pretty_printer(
>      gdb.current_objfile(),
> -    build_pretty_printer())
> +    build_pretty_printer(),
> +    replace=True)
>  
>  def find_gcc_source_dir():
>      # Use location of global "g" to locate the source tree
> -- 
> 2.22.0
>
>
> OK?

I actually think, that change is obvious.  It has proven useful and I've
not run into any issues with it.

> BTW, perhaps I should also add a convenience function for 'import imp;
> imp.reload(gdbhooks)' or something to that effect?

I added a user-defined gdb command and a short alias for it.  I think,
this is obvious too, but would feel more comfortable if someone OKs it.
Dave?

[PATCH] gdbinit.in: add reload-gdbhooks (rh) command

gcc/
        * gdbinit.in (reload-gdbhooks): New command with an attached doc string.
        (rh): New alias for it.
---
 gcc/gdbinit.in | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/gcc/gdbinit.in b/gcc/gdbinit.in
index cec55f86749..2454441f859 100644
--- a/gcc/gdbinit.in
+++ b/gcc/gdbinit.in
@@ -216,6 +216,16 @@ is emitted (as opposed to those warnings that are suppressed by
 command-line options).
 end
 
+define reload-gdbhooks
+python import imp; imp.reload(gdbhooks)
+end
+
+document reload-gdbhooks
+Load the gdbhooks.py module again in order to pick up any changes made to it.
+end
+
+alias rh = reload-gdbhooks
+
 # Define some macros helpful to gdb when it is expanding macros.
 macro define __FILE__ "gdb"
 macro define __LINE__ 1
-- 
2.22.0

Thanks,
Vlad