我有一个几乎工作的SConstruct文件。我目前没有使用任何SConscript文件，并且我不希望在我的源代码库中使用任何文件（git，而不是SCons）。
快速摘要 - 我的问题发生在更改一些参数，然后返回到以前的参数，重建相同的文件。
我运行scons -f Builder_repo/SConstruct 'NameOfTargetLibrary.b'来建立一个库，NameOfTargetLibrary.b来自NameOfTargetLibrary.src。
<lib>.b应该放在一个依赖于各种标志的位置（Debug / Release，32/64位，平台（来自列表）），如下所示：
topdir
|\-- Builder_repo (containing SConstruct, site_scons\...)
|\-- Lib1 (contains lib1.src, bunch of source files)
|\-- Lib2 (lib2.src, lib2 sources)
\--- BuiltLibs
|\-- Windows
| |\-- Release_32
| | |\-- lib1.b
| | |\-- lib2.b
| | \--- libn.b
| |\-- Debug_64
| | |\-- lib1.b
| | |\-- lib2.b
| | \--- libn.b
| \--- (Debug_32, Release_64)
\--- (etc, other targets, currently just one)
命令行类似（为了便于阅读，分为多行，但在SCons / cmdLine中只有一行）
"abspath to exe" "static path and args" --x64 --
"abspath(lib1.src)" "abspath(BuiltLibs)"
"abspath(BuiltLibs/Windows/Release_64)"
"flags for debug/release, target, bitness"
“工作”SConstruct使用一个带有generate(env)的工具，例如：
BuiltLibs\Windows\Release_32）存储在env中。.src文件os.path.dirname）env.Repositories(dirname(lib.src))tgt = env.BLDR(<TARGETDIR>/lib.b, lib.src)env.Alias(lib.b, tgt)然后，Builder使用Emitter将source所依赖的任何<TARGETDIR>/libx.b文件添加到lib.src列表中（从源文件中读取）。如果可取的话，可以将它们添加为libx.b？
Generator解析输入目标和源列表以形成它返回的命令行。对于当前配置，目标和源都是相对路径，因此可能不需要Repository调用。
我跑的时候
scons -f Builder_repo\SConstruct 'lib2.b' DEBUG=0 BITNESS=32 TRGT=Windows
（lib2.src取决于lib1.b，由于发射器），正确的lib1.b和lib2.b被构建并放置在BuiltLibs\Windows\Release_32\lib{1,2}.b中。
如果我重复命令，那么就不会构建任何内容并且'lib2.b是最新的'。
然后，我尝试scons -f <..> 'lib2.b' DEBUG=1 <other args same>。两个库都按照预期构建并放置在BuiltLibs\Windows\Debug_32\lib{1,2}.b中。
当我再次尝试第一个命令（DEBUG=0）时，我希望不会构建任何内容（lib1.b，lib2.b仍然是最新的 - 没有更改源并且之前构建的文件仍在Release_32中）但是它们被重建。
当for_signature为true时，我试图通过返回一个简化的命令行来解决这个问题，这样在这种情况下返回的值更像是：
"abspath to exe" "static path and args" --
"abspath(lib1.src)" "abspath(BuiltLibs)" "version string"
其中“版本字符串”不受调试/发布，32/64，平台标志的影响（但确实随源代码而变化）。这似乎没有什么区别。
我尝试使用env.VariantDir(<TARGETDIR>, '.', duplicate=0)和tgt = env.BLDR(lib.b, Lib1/lib.src)，env.Alias(<TARGETDIR>/lib.b, tgt)或类似的一些变体，但我没有设法改进任何东西（一些配置只是让它总是重建，其他配置使得依赖无法找到，SCons错误。
我该怎么做？
SConstruct：
import os
Decider('make')
Default(None)
# Add command line arguments with default values.
# These can be specified as, for example, LV_TARGET=cRIO
cmdVars = Variables(None, ARGUMENTS)
cmdVars.AddVariables(
EnumVariable('LV_TARGET', 'Choose the target for LabVIEW packages',
'Windows', allowed_values=('Windows', 'cRIO')),
BoolVariable('DEBUG', 'Set to 1 to build a debug-enabled package', 0),
EnumVariable('BITNESS', 'Choose the bitness for LabVIEW packages',
'32', allowed_values=('32', '64')),
EnumVariable('LV_VER', 'Choose the version of LabVIEW to use',
'2017', allowed_values=('2017',))
)
# Define a list of source extensions
src_exts = ['.vi', '.ctl', '.lvlib', '.vim', '.vit']
env = Environment(variables = cmdVars, ENV = os.environ, tools=['PPL'], PPLDIR='PPLs', SRC_EXTS=' '.join(src_exts))
用于PPL工具的init.py：
""" SCons.Tool.PPL
Tool-specific initialization for compilation of lvlibp files from lvlib files,
using the Wiresmith 'labview-cli.exe' and the LabVIEW code stored in the
PPL_Builder GitHub repository.
This module should not usually be imported directly.
It can be imported using a line in SConstruct or SConscript like
env = Environment(tools=['PPL'])
"""
# A reference for this code can be found at
# https://github.com/SCons/scons/wiki/ToolsForFools
# which describes the creation of a Tool for JALv2 compilation.
import SCons.Builder
from SCons.Script import GetOption
import SCons.Node
import SCons.Util
import os.path
import textwrap
import re
import contextlib
import subprocess
# Add warning classes
class ToolPPLWarning(SCons.Warnings.Warning):
pass
class LabVIEW_CLI_ExeNotFound(ToolPPLWarning):
pass
SCons.Warnings.enableWarningClass(ToolPPLWarning)
__verbose = False
class LV_BuildPaths:
""" A simple class to contain the build paths
and configuration flags for PPL compilation
Contains the attributes:
hwTarget{,Dir}, debug{Opt,Flag,String}, bitness{,Flag}, lv_ver,
{ppl,storage,copy,topData,data}Dir
"""
def __init__(self, env):
# Set the target parameters
self.hwTarget = env.get('LV_TARGET')
copyDirExtra = ""
if self.hwTarget == "cRIO":
self.hwTargetDir = "cRIO-9045"
copyDirExtra = os.path.join('home','lvuser','natinst','bin')
else:
self.hwTargetDir = self.hwTarget
# Set the debug parameters
self.debugOpt = env.get('DEBUG')
self.debugFlag = int(self.debugOpt)
self.debugString = "Debug" if self.debugOpt else "Release"
# Set the bitness parameters
self.bitness = env.get('BITNESS')
self.bitnessFlag = ''
if self.bitness == '64':
self.bitnessFlag = '--x64'
# Get the LabVIEW year
self.lv_ver = env.get('LV_VER')
# Get important build directory paths.
# PPL files should be searched for in storageDir
self.pplDir = os.path.normpath(env.get('PPLDIR', 'PPLs'))
self.storageDir = os.path.join(self.pplDir, self.hwTargetDir, f'{self.debugString}_{self.bitness}', copyDirExtra)
self.copyDir = os.path.join(self.pplDir, self.hwTargetDir, copyDirExtra)
self.topDataDir = os.path.join(self.pplDir, 'Data')
self.dataDir = os.path.join(self.copyDir, 'Data')
def __str__(self):
return (textwrap.dedent(f"""\
The directories are as follows...
PPL Dir: {self.pplDir}
Storage Dir: {self.storageDir}
Copy Dir: {self.copyDir}""")
)
def _print_info(message):
""" Disable the output of messages if '--quiet', '-s' or '--silent'
are passed to the command line """
if not GetOption('silent'):
print(message)
def _detectCLI(env):
""" Search for the labview-cli.exe installed by Wiresmith's VIPackage """
try:
# If defined in the environment, use this
_print_info(f"labview-cli defined in the environment at {env['LV_CLI']}")
return env['LV_CLI']
except KeyError:
pass
cli = env.WhereIs('labview-cli')
if cli:
_print_info(f"Found labview-cli at {cli}")
return cli
raise SCons.Errors.StopError(
LabVIEW_CLI_ExeNotFound,
"Could not detect the labview-cli executable")
return None
@contextlib.contextmanager
def pushd(new_dir):
previous_dir = os.getcwd()
os.chdir(new_dir)
yield
os.chdir(previous_dir)
def _getHash(env, dir):
if env['GIT_EXE']:
with pushd(dir):
#cmdLine = env['git_showref']
cmdLine = env['git_describe']
return subprocess.run(cmdLine, shell=True, capture_output=True, text=True).stdout
return ''
def _detectGit(env):
""" Search for a git executable. This is not required for usage """
git = None
try:
# If defined in the environment, use this
_print_info(f"git executable defined in the environment at {env['GIT_EXE']}")
git = env['GIT_EXE']
except KeyError:
pass
cli = env.WhereIs('git')
if cli:
_print_info(f"Found git at {cli}")
git = cli
if git:
hash_len = 12
env['GIT_EXE'] = f"'{git}'" # I edited this line compared to the version in the repository, but I don't think it's relevant.
env['git_describe'] = f'"{git}" describe --dirty="*" --long --tags --always --abbrev={hash_len}'
env['git_showref'] = f'"{git}" show-ref --hash={hash_len} --head head'
return None
#
# Builder, Generator and Emitter
#
def _ppl_generator(source, target, env, for_signature):
""" This function generates the command line to build the PPL.
It should expect to receive a target as a relative path
['<SD>/A.lvlibp'], and source will be either None, or
['<src>/A.lvlib'].
When for_signature == 0, the PPL will actually be built.
"""
# Get these parameters properly
run_vi = os.path.abspath(os.path.join('.','PPL_Builder','Call_Builder_Wiresmith.vi'))
cliOpts = ''
package_ver = "0.0.0.0#sconsTest"
# These are extracted from the environment
cli = env['LV_CLI']
bp = env['LV_Dirs']
ver = bp.lv_ver
pplDir = f'{os.path.abspath(bp.pplDir)}'
storageDir = f'{os.path.abspath(bp.storageDir)}'
# Dependencies are parsed for the command line. They are already dependencies of the target.
pplSrcs = source[1:]
depsString = ""
if pplSrcs:
if __verbose:
_print_info("Adding PPL dependencies: %s" % [ str(ppl) for ppl in pplSrcs ])
depsString = " ".join([f'"{os.path.basename(ppl.get_string(for_signature))}"' for ppl in pplSrcs])
cmdLine = f'"{cli}" --lv-ver {ver} {bp.bitnessFlag} {run_vi} {cliOpts} -- '
lvlib_relpath = str(source[0])
lvlib_abspath = os.path.abspath(lvlib_relpath)
git_ver = _getHash(env, os.path.dirname(lvlib_abspath))
print("git version is " + str(git_ver).strip())
argsLine = f'"{lvlib_abspath}" "{pplDir}" "{storageDir}" {bp.debugFlag} {bp.hwTarget} "{package_ver}" {depsString}'
if not for_signature:
_print_info(f"Making {lvlib_abspath}")
return cmdLine + argsLine
#return cmdLine + argsLine
def _ppl_emitter(target, source, env):
""" Appends any dependencies found in the .mk file to the list of sources.
The target should be like [<SD>/A.lvlibp],
and the source should be like [<src>/A.lvlib]
"""
if not source:
return target, source
exts_tuple = tuple(env['SRC_EXTS'].split(' '))
src_files = _get_other_deps(source, exts_tuple)
if __verbose:
_print_info("Adding " + str(src_files) + " as dependencies")
env.Depends(target, src_files)
depsList, nodeDepsList = _get_ppl_deps(str(source[0]), env)
if nodeDepsList:
source += [os.path.normpath(os.path.join(env['LV_Dirs'].storageDir, str(pplNode))) for pplNode in nodeDepsList]
return target, source
_ppl_builder = SCons.Builder.Builder(generator = _ppl_generator, emitter = _ppl_emitter)
def lvlibpCreator(env, target, source=None, *args, **kw):
""" A pseudo-Builder for the labview-cli executable
to build .lvlibp files from .lvlib sources, with
accompanying dependency checks on appropriate source files
Anticipate this being called via env.PPL('<SD>/A.lvlibp'),
where target is a string giving a relative path, or
env.PPL('<SD>/A.lvlibp', '<src>/A.lvlib')
"""
bPaths = env['LV_Dirs']
# Ensure that if source exists, it is a list
if source and not SCons.Util.is_List(source):
source = [source]
if __verbose:
_print_info(f"Target = {target}")
if source:
_print_info("Sources = %s" % [ str(s) for s in source])
if __verbose:
_print_info("args: %s" % [ str(s) for s in args ])
_print_info("kw: %s" % str(kw.items()))
tgt = _ppl_builder.__call__(env, target, source, **kw)
return tgt
def _scanForLvlibs(env, topdir=None):
# Maybe check this...
if not topdir:
topdir = '.'
bPaths = env['LV_Dirs']
lvlibList = []
for root, dirs, files in os.walk(topdir):
# if any of files ends with .lvlib, add to the list
lvlibList += map(lambda selected: os.path.join(root, selected), filter(lambda x: x[-6:] == '.lvlib', files))
for lib in lvlibList:
# Set up the possibility of building the lvlib
(srcDir, libnameWithExt) = os.path.split(lib)
# Add the source repository
if __verbose:
_print_info("Adding repository at: " + srcDir)
env.Repository(srcDir)
# Add the build instruction
lvlibpName = libnameWithExt + 'p'
tgt = env.PPL(os.path.normpath(os.path.join(bPaths.storageDir, lvlibpName)),lib)
if __verbose:
_print_info(f"Adding alias from {libnameWithExt+'p'} to {str(tgt)}")
env.Alias(lvlibpName, tgt)
def _get_ppl_deps(lvlib, env):
lvlib_s = str(lvlib)
lvlib_name = os.path.basename(lvlib_s)
mkFile = lvlib_s.replace('.lvlib','.mk')
if os.path.isfile(mkFile):
# load dependencies from file
depVarName = lvlib_name.replace(' ',r'\+').replace('.lvlib','_Deps')
f = open(mkFile, "r")
content = f.readlines() # Read all lines (not just first)
depsList = []
for line in content:
matchedDeps = re.match(depVarName+r'[ ]?:=[ ]?(.*)$', line)
if matchedDeps:
listDeps = matchedDeps.group(1).replace(r'\ ','+').split(' ')
depsList = ['"' + elem.replace('+', ' ') + '"' for elem in listDeps]
nodeList = [ env.File(elem.replace('+', ' ')) for elem in listDeps]
return (depsList, nodeList)
raise RuntimeError("Found a .mk file ({mkFile}) but could not parse it to get dependencies.")
#print(f"No .mk file for {lvlib_name}")
return ('', None)
def _get_other_deps(source, exts):
parent_dir = os.path.dirname(str(source[0]))
if __verbose:
_print_info(f"Searching {parent_dir} for source files...")
_print_info(f"Acceptable extensions are {exts}")
src_files = []
for root, dirs, files in os.walk(parent_dir):
src_files += [os.path.join(root, file) for file in files if file.endswith(exts)]
return src_files
def generate(env):
'''Add builders and construction variables to the Environment.'''
env['LV_CLI'] = _detectCLI(env)
env.AddMethod(lvlibpCreator, "PPL")
_detectGit(env)
bp = LV_BuildPaths(env)
_print_info(bp)
env['LV_Dirs'] = bp
# Search for all lvlib files
_scanForLvlibs(env)
def exists(env):
return _detectCLI(env)
正如在评论中简要描述的那样，重建的原因是使用Decider('make')（即按时间戳检查）和有效的源文件捕获自动生成的文件。
在bdbaddog在问题的评论中建议运行scons --debug=explain时很容易看到这一点。
虽然稍微脆，但最简单的解决方案是修改发射器，留下以下内容（参见--->标记）：
def _ppl_emitter(target, source, env):
""" Appends any dependencies found in the .mk file to the list of sources.
The target should be like [<SD>/A.lvlibp],
and the source should be like [<src>/A.lvlib]
"""
if not source:
return target, source
exts_tuple = tuple(env['SRC_EXTS'].split(' '))
src_files = _get_other_deps(source, exts_tuple)
--->filtered_files = list(filter(lambda x: "Get PPL Version.vi" not in x, src_files))
if __verbose:
_print_info("Adding " + str(filtered_files) + " as dependencies")
env.Depends(target, filtered_files)
depsList, nodeDepsList = _get_ppl_deps(str(source[0]), env)
if nodeDepsList:
source += [os.path.normpath(os.path.join(env['LV_Dirs'].storageDir, str(pplNode))) for pplNode in nodeDepsList]
return target, source
通过删除此文件，目标不再对生成的文件具有显式依赖性（这与Decider调用无关）。
另外，从SConstruct文件中删除Decider('make')行允许删除整个源存储库并重新加载，而不会触发重建。
作为旁注，Git特定的代码也被删除并放置在Builder调用的代码中 - 这样，它还需要（为了减少代码的好处）只在需要重建时调用（而不是每次都调用） SCons运行）。