[Python-Dev] what environment variable should contain compiler warning suppression flags? (original) (raw)

Steve Holden steve at holdenweb.com
Tue Jun 29 17:29:55 CEST 2010

Barry Warsaw wrote:

On Jun 28, 2010, at 05:28 PM, M.-A. Lemburg wrote:

How many Python users will compile Python in debug mode ? How many Python users compile Python at all? :) The point is that the default build of Python should use the correct production settings for the C compiler out of the box and that's what ACPROGCC is all about. Sure. I'm pretty sure that Python developers who want to use a debug build have enough code foo to get the -O2 turned into a -O0 either by adjust OPT and/or by providing their own CFLAGS env var. Yes, but it's a PITA for several reasons, IMO: * It's pretty underdocumented * It's obscure * It's hard to remember the exact fu needed because you do it infrequently * I usually only remember my mistake when gdb acts funny I strongly suggest that --with-pydebug should be all you need to ensure the best debugging environment, which means turning off compiler optimization. Last time I tried, the -O0 was added and it worked well. (I know this has been in flux though.) Also note that in some cases you may actually want to have a debug build with optimizations turned on, e.g. to track down a compiler optimization bug. Yes, but that's much more rare than wanting to step through some bit of C code without going crazy.

I agree - trying to step through -O2 optimized code isn't going to help debug your code, it's going to help you debug the optimizer. That's a very rare use case.

regards Steve

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