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| author | Sye van der Veen <syeberman@rogers.com> | 2014-03-16 19:49:18 (GMT) |
|---|---|---|
| committer | Sye van der Veen <syeberman@rogers.com> | 2014-03-16 19:49:18 (GMT) |
| commit | 6f7255096462195be3ea812b4dcf9dbee6d08ef0 (patch) | |
| tree | faa1e3ad1211f028bdbcd3f4239a5395c576c22e | |
| parent | bf075e2a9c29b35fe8908d1b91c470c4b2c823a8 (diff) | |
| download | SCons-6f7255096462195be3ea812b4dcf9dbee6d08ef0.zip SCons-6f7255096462195be3ea812b4dcf9dbee6d08ef0.tar.gz SCons-6f7255096462195be3ea812b4dcf9dbee6d08ef0.tar.bz2 | |
Update comments to clarify benefits of script_env memoization
| -rw-r--r-- | src/engine/SCons/Tool/MSCommon/vc.py | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/engine/SCons/Tool/MSCommon/vc.py b/src/engine/SCons/Tool/MSCommon/vc.py index b5491b1..72e7c77 100644 --- a/src/engine/SCons/Tool/MSCommon/vc.py +++ b/src/engine/SCons/Tool/MSCommon/vc.py @@ -299,9 +299,12 @@ def reset_installed_vcs(): __INSTALLED_VCS_RUN = None # Running these batch files isn't cheap: most of the time spent in -# msvs.generate() is due to vcvars*.bat. In a build that keeps separate -# environments for debug and release, or perhaps builds against multiple -# MSVS versions at once, we can save a lot of time by caching the output. +# msvs.generate() is due to vcvars*.bat. In a build that uses "tools='msvs'" +# in multiple environments, for example: +# env1 = Environment(tools='msvs') +# env2 = Environment(tools='msvs') +# we can greatly improve the speed of the second and subsequent Environment +# (or Clone) calls by memoizing the environment variables set by vcvars*.bat. script_env_stdout_cache = {} def script_env(script, args=None): cache_key = (script, args) |