Hi, 2015-10-22 19:02 GMT+02:00 Brett Cannon <br...@python.org>: > It's not specified anywhere; it's just what the peepholer decides to remove. > The exact code can be found at > https://hg.python.org/cpython/file/default/Python/peephole.c . There has > been talk in the past for adding a -X flag to disable the peepholer, but it > never went any farther beyond that.
Yeah, I remember that I had the same issue than Stéphane when I worked on my astoptimizer project :-) I wanted to completly disable the peephole optimizer because I wanted to reimplement the optimizations on the AST instead of rewriting the bytecode. I would be nice to have a "-X noopt" command line option for that. By the way, the peephole optimizer cannot remove "if 0: yield" because it's a workaround of a limitation in CPython. It's not possible to declare that a function is a generator even if it doesn't call yield. Well, "async def" solves partially the issue, but sometimes you don't want generators with "async def". If I recall correctly, another usecase of "-X noopt" is code coverage: the peephole optimizers punchs holes in the code coverage because it looks like some lines are never executed. Note: I propose "noopt" because we already have "optimization level 0" which still uses optimizations, it's the default mode. It's different than gcc -O0 which really disables all optimizations. I already prefix the "noopt" suffix for .pyc files than "opt--1" proposed by Brett in http://bugs.python.org/issue2506 Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
