The code generation in gem5's build system requires the use of Regular
Expression flags when defining the regular expressions used for
tokenization. However, the Python Lex-Yacc (PLY) [1] library used by
gem5 does not allow the user sufficient control of the flags for RE
compilation.
Previously, gem5 used inline RE flags to control RE compilation.
However, from Python 3.11, inline RE flags must be at the start of the
RE string. Because PLY wraps the user supplied RE strings before
compilation, there is no way for the user to supply a RE string with
the inline flag at the start. This makes gem5 incompatible with Python
3.11 when using PLY.
This change modifies gem5's build files to patch `re.compile` with a
wrapped version that can handle embedded flags anywhere in the RE
string, for all current versions of Python. The patched version
re-formats the user supplied RE string to convert inline RE flags to
explicit RE flags.
This patch is intended as a temporary stop-gap until PLY can be fixed
upstream.
See the gem5 Issue Tracker [2] for more details.
[1] https://github.com/dabeaz/ply
[2] https://gem5.atlassian.net/browse/GEM5-1321
Change-Id: I3ab371f2e5cf267c0a89caaf8a2bacfed78545ef
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/70237
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Boris Shingarov <shingarov@labware.com>
Tested-by: kokoro <noreply+kokoro@google.com>
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