带有 AddOption 的 SCons 不捕获所有指定的标志
SCons with AddOption does not capture all specified flags
我在 SCons 中遇到 AddOption 问题，我在其中为单个选项指定了多个标志。它没有拿起其中一面旗帜。在此示例中，我希望 -V 和 --verbose 都触发相同的选项，但它仅适用于 --verbose.
这是一个最小的工作示例。
./SConstruct
AddOption("-V", "--verbose",
action="store_true", dest="verbose", default=False,
help="Print everything to stdout")
if not GetOption('help'):
if GetOption('verbose'):
print '## VERBOSITORY IS ON ##'
else:
print '## VERBOSITORY IS OFF ##'
当 运行 我们得到以下...
+ scons --help
scons: Reading SConscript files ...
scons: done reading SConscript files.
usage: scons [OPTION] [TARGET] ...
SCons Options:
-b, -d, -e, -m, -S, -t, -w, --environment-overrides, --no-keep-going,
--no-print-directory, --print-directory, --stop, --touch
Ignored for compatibility.
-c, --clean, --remove Remove specified targets and dependencies.
-C DIR, --directory=DIR Change to DIR before doing anything.
--cache-debug=FILE Print CacheDir debug info to FILE.
--cache-disable, --no-cache
Do not retrieve built targets from CacheDir.
--cache-force, --cache-populate
Copy already-built targets into the CacheDir.
--cache-readonly Do not update CacheDir with built targets.
--cache-show Print build actions for files from CacheDir.
--config=MODE Controls Configure subsystem: auto, force,
cache.
-D Search up directory tree for SConstruct,
build all Default() targets.
--debug=TYPE Print various types of debugging information:
count, duplicate, explain, findlibs, includes,
memoizer, memory, objects, pdb, prepare,
presub, stacktrace, time.
--diskcheck=TYPE Enable specific on-disk checks.
--duplicate=DUPLICATE Set the preferred duplication methods. Must be
one of hard-soft-copy, soft-hard-copy,
hard-copy, soft-copy, copy
-f FILE, --file=FILE, --makefile=FILE, --sconstruct=FILE
Read FILE as the top-level SConstruct file.
-h, --help Print defined help message, or this one.
-H, --help-options Print this message and exit.
-i, --ignore-errors Ignore errors from build actions.
-I DIR, --include-dir=DIR Search DIR for imported Python modules.
--implicit-cache Cache implicit dependencies
--implicit-deps-changed Ignore cached implicit dependencies.
--implicit-deps-unchanged Ignore changes in implicit dependencies.
--interact, --interactive Run in interactive mode.
-j N, --jobs=N Allow N jobs at once.
-k, --keep-going Keep going when a target can't be made.
--max-drift=N Set maximum system clock drift to N seconds.
--md5-chunksize=N Set chunk-size for MD5 signature computation to
N kilobytes.
-n, --no-exec, --just-print, --dry-run, --recon
Don't build; just print commands.
--no-site-dir Don't search or use the usual site_scons dir.
--profile=FILE Profile SCons and put results in FILE.
-q, --question Don't build; exit status says if up to date.
-Q Suppress "Reading/Building" progress messages.
--random Build dependencies in random order.
-s, --silent, --quiet Don't print commands.
--site-dir=DIR Use DIR instead of the usual site_scons dir.
--stack-size=N Set the stack size of the threads used to run
jobs to N kilobytes.
--taskmastertrace=FILE Trace Node evaluation to FILE.
--tree=OPTIONS Print a dependency tree in various formats: all,
derived, prune, status.
-u, --up, --search-up Search up directory tree for SConstruct,
build targets at or below current directory.
-U Search up directory tree for SConstruct,
build Default() targets from local SConscript.
-v, --version Print the SCons version number and exit.
--warn=WARNING-SPEC, --warning=WARNING-SPEC
Enable or disable warnings.
-Y REPOSITORY, --repository=REPOSITORY, --srcdir=REPOSITORY
Search REPOSITORY for source and target files.
Local Options:
-V, --verbose Print everything to stdout
+ scons --version
SCons by Steven Knight et al.:
script: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine path: ['/usr/lib/scons/SCons']
Copyright (c) 2001 - 2014 The SCons Foundation
+ scons -v
SCons by Steven Knight et al.:
script: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine path: ['/usr/lib/scons/SCons']
Copyright (c) 2001 - 2014 The SCons Foundation
+ scons
scons: Reading SConscript files ...
## VERBOSITORY IS OFF ##
scons: done reading SConscript files.
scons: Building targets ...
scons: `.' is up to date.
scons: done building targets.
+ scons --verbose
scons: Reading SConscript files ...
## VERBOSITORY IS ON ##
scons: done reading SConscript files.
scons: Building targets ...
scons: `.' is up to date.
scons: done building targets.
+ scons -V
usage: scons [OPTION] [TARGET] ...
SCons Error: no such option: -V
那么为什么我在传递 -V 时出现错误？
SCons 多次解析参数列表。您的错误源于第一遍，甚至在读入 SConscripts 之前，并且只允许内置参数...所以您的 AddOption() 还没有效果。
事实上，在SConscript中，通过AddOption方法是不可能添加一个像“-V”这样的短选项的。只有长选项，比如你的“--verbose”，不会立即破坏构建。在 src/engine/Script/SConsOptions.py 中，方法 SConsOptionParser._process_long_opt() 捕获实际的异常，这样在第二次尝试中（在读取所有 SConscripts/SConstructs 之后）解析可能会成功。
我在 SCons 中遇到 AddOption 问题，我在其中为单个选项指定了多个标志。它没有拿起其中一面旗帜。在此示例中，我希望 -V 和 --verbose 都触发相同的选项，但它仅适用于 --verbose.
这是一个最小的工作示例。
./SConstruct
AddOption("-V", "--verbose",
action="store_true", dest="verbose", default=False,
help="Print everything to stdout")
if not GetOption('help'):
if GetOption('verbose'):
print '## VERBOSITORY IS ON ##'
else:
print '## VERBOSITORY IS OFF ##'
当 运行 我们得到以下...
+ scons --help
scons: Reading SConscript files ...
scons: done reading SConscript files.
usage: scons [OPTION] [TARGET] ...
SCons Options:
-b, -d, -e, -m, -S, -t, -w, --environment-overrides, --no-keep-going,
--no-print-directory, --print-directory, --stop, --touch
Ignored for compatibility.
-c, --clean, --remove Remove specified targets and dependencies.
-C DIR, --directory=DIR Change to DIR before doing anything.
--cache-debug=FILE Print CacheDir debug info to FILE.
--cache-disable, --no-cache
Do not retrieve built targets from CacheDir.
--cache-force, --cache-populate
Copy already-built targets into the CacheDir.
--cache-readonly Do not update CacheDir with built targets.
--cache-show Print build actions for files from CacheDir.
--config=MODE Controls Configure subsystem: auto, force,
cache.
-D Search up directory tree for SConstruct,
build all Default() targets.
--debug=TYPE Print various types of debugging information:
count, duplicate, explain, findlibs, includes,
memoizer, memory, objects, pdb, prepare,
presub, stacktrace, time.
--diskcheck=TYPE Enable specific on-disk checks.
--duplicate=DUPLICATE Set the preferred duplication methods. Must be
one of hard-soft-copy, soft-hard-copy,
hard-copy, soft-copy, copy
-f FILE, --file=FILE, --makefile=FILE, --sconstruct=FILE
Read FILE as the top-level SConstruct file.
-h, --help Print defined help message, or this one.
-H, --help-options Print this message and exit.
-i, --ignore-errors Ignore errors from build actions.
-I DIR, --include-dir=DIR Search DIR for imported Python modules.
--implicit-cache Cache implicit dependencies
--implicit-deps-changed Ignore cached implicit dependencies.
--implicit-deps-unchanged Ignore changes in implicit dependencies.
--interact, --interactive Run in interactive mode.
-j N, --jobs=N Allow N jobs at once.
-k, --keep-going Keep going when a target can't be made.
--max-drift=N Set maximum system clock drift to N seconds.
--md5-chunksize=N Set chunk-size for MD5 signature computation to
N kilobytes.
-n, --no-exec, --just-print, --dry-run, --recon
Don't build; just print commands.
--no-site-dir Don't search or use the usual site_scons dir.
--profile=FILE Profile SCons and put results in FILE.
-q, --question Don't build; exit status says if up to date.
-Q Suppress "Reading/Building" progress messages.
--random Build dependencies in random order.
-s, --silent, --quiet Don't print commands.
--site-dir=DIR Use DIR instead of the usual site_scons dir.
--stack-size=N Set the stack size of the threads used to run
jobs to N kilobytes.
--taskmastertrace=FILE Trace Node evaluation to FILE.
--tree=OPTIONS Print a dependency tree in various formats: all,
derived, prune, status.
-u, --up, --search-up Search up directory tree for SConstruct,
build targets at or below current directory.
-U Search up directory tree for SConstruct,
build Default() targets from local SConscript.
-v, --version Print the SCons version number and exit.
--warn=WARNING-SPEC, --warning=WARNING-SPEC
Enable or disable warnings.
-Y REPOSITORY, --repository=REPOSITORY, --srcdir=REPOSITORY
Search REPOSITORY for source and target files.
Local Options:
-V, --verbose Print everything to stdout
+ scons --version
SCons by Steven Knight et al.:
script: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine path: ['/usr/lib/scons/SCons']
Copyright (c) 2001 - 2014 The SCons Foundation
+ scons -v
SCons by Steven Knight et al.:
script: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine: v2.3.4, 2014/09/27 12:51:43, by garyo on lubuntu
engine path: ['/usr/lib/scons/SCons']
Copyright (c) 2001 - 2014 The SCons Foundation
+ scons
scons: Reading SConscript files ...
## VERBOSITORY IS OFF ##
scons: done reading SConscript files.
scons: Building targets ...
scons: `.' is up to date.
scons: done building targets.
+ scons --verbose
scons: Reading SConscript files ...
## VERBOSITORY IS ON ##
scons: done reading SConscript files.
scons: Building targets ...
scons: `.' is up to date.
scons: done building targets.
+ scons -V
usage: scons [OPTION] [TARGET] ...
SCons Error: no such option: -V
那么为什么我在传递 -V 时出现错误？
SCons 多次解析参数列表。您的错误源于第一遍，甚至在读入 SConscripts 之前，并且只允许内置参数...所以您的 AddOption() 还没有效果。
事实上，在SConscript中，通过AddOption方法是不可能添加一个像“-V”这样的短选项的。只有长选项，比如你的“--verbose”，不会立即破坏构建。在 src/engine/Script/SConsOptions.py 中，方法 SConsOptionParser._process_long_opt() 捕获实际的异常，这样在第二次尝试中（在读取所有 SConscripts/SConstructs 之后）解析可能会成功。