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classification
Title: --with-pydebug builds now include -O2 by default
Type: behavior Stage:
Components: Build Versions: Python 3.2, Python 2.7
process
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: mark.dickinson Nosy List: Arfrever, lemburg, mark.dickinson, pitrou, vstinner
Priority: normal Keywords: patch

Created on 2010年05月05日 14:03 by mark.dickinson, last changed 2022年04月11日 14:57 by admin. This issue is now closed.

Files
File name Uploaded Description Edit
no_debug_optimization.patch mark.dickinson, 2010年05月05日 14:03
Messages (6)
msg105035 - (view) Author: Mark Dickinson (mark.dickinson) * (Python committer) Date: 2010年05月05日 14:03
When doing a debug build of Python with gcc, without any previous setting of CFLAGS, the '-O2' flag is now automatically included.
This behaviour started in r79218.
It would be nice to restore the original behaviour, if possible, since the optimization causes difficulties when debugging. One solution would be to add '-O0' to OPT for debug builds (on gcc), as in the attached patch. You then get compiler flags including:
"-g -O2 -g -O0"
which is somewhat ugly, but the -O0 overrides the -O2 (I think). Does this seem like a reasonable solution?
msg105037 - (view) Author: Mark Dickinson (mark.dickinson) * (Python committer) Date: 2010年05月05日 14:08
Just double checked the gcc manual. From:
http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
"""If you use multiple -O options, with or without level numbers, the last such option is the one that is effective."""
msg105038 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2010年05月05日 14:10
> It would be nice to restore the original behaviour, if possible, since
> the optimization causes difficulties when debugging. One solution
> would be to add '-O0' to OPT for debug builds (on gcc), as in the
> attached patch. You then get compiler flags including:
> 
> "-g -O2 -g -O0"
> 
> which is somewhat ugly, but the -O0 overrides the -O2 (I think). Does
> this seem like a reasonable solution?
Probably good enough.
msg105049 - (view) Author: Marc-Andre Lemburg (lemburg) * (Python committer) Date: 2010年05月05日 15:27
Antoine Pitrou wrote:
> 
> Antoine Pitrou <pitrou@free.fr> added the comment:
> 
>> It would be nice to restore the original behaviour, if possible, since
>> the optimization causes difficulties when debugging. One solution
>> would be to add '-O0' to OPT for debug builds (on gcc), as in the
>> attached patch. You then get compiler flags including:
>>
>> "-g -O2 -g -O0"
>>
>> which is somewhat ugly, but the -O0 overrides the -O2 (I think). Does
>> this seem like a reasonable solution?
> 
> Probably good enough.
+1
OPT can also be overridden by the user, to e.g. actually get an
optimized debug build in order to debug compiler optimization
problems.
msg105103 - (view) Author: Mark Dickinson (mark.dickinson) * (Python committer) Date: 2010年05月05日 22:33
Applied in r80832 (trunk), r80834 (py3k). Thanks, all.
msg105114 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2010年05月06日 00:31
Thanks!
History
Date User Action Args
2022年04月11日 14:57:00adminsetgithub: 52871
2010年05月06日 00:31:46vstinnersetmessages: + msg105114
2010年05月05日 22:33:53mark.dickinsonsetstatus: open -> closed
assignee: mark.dickinson
resolution: fixed
messages: + msg105103
2010年05月05日 15:27:23lemburgsetmessages: + msg105049
2010年05月05日 15:21:55Arfreversetnosy: + Arfrever
2010年05月05日 14:10:58pitrousetmessages: + msg105038
2010年05月05日 14:08:30mark.dickinsonsetmessages: + msg105037
2010年05月05日 14:03:48mark.dickinsoncreate

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