make gdbhooks.py idempotent with respect to reloading

Message ID 87h88ac4fl.fsf@ispras.ru
State New
Headers show
Series
  • make gdbhooks.py idempotent with respect to reloading
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Commit Message

Vladislav Ivanishin June 28, 2019, 11:52 a.m.
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
OK?

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

-- 
Vlad

Comments

Vladislav Ivanishin July 2, 2019, 10:39 p.m. | #1
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
Vladislav Ivanishin July 23, 2019, 2:06 p.m. | #2
Vladislav Ivanishin <vlad@ispras.ru> writes:

> 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


Committed both patches as obvious, revisions 273737 and 273738
respectively.

-- 
Vlad

Patch

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