[Scons-users] File / Dir relative paths and SConscriptChdir

[Bill Deegan]

# You shouldn't need to do this.  Python's open will handle either slash on
windows.
# header = env.subst('${HEADER_BUILD}/mpversion.h')
# header = os.path.normpath(header)

# you shouldn't need to do this as ${TOP}. will get expanded by execute
# script = env.subst('${TOP}/py/makeversionhdr.py')
# script = os.path.abspath(script)

# Why do you need chdir?  Do you control the script?
env.Execute("'${TOP}/py/makeversionhdr.py ${HEADER_BUILD}/mpversion.h",
chdir=env.GetLaunchDir())

-Bill

On Thu, Sep 6, 2018 at 9:57 PM RW via Scons-users <scons-users at scons.org>
wrote:

> Hi Bill,
> I've replaced File with os.path.normpath / os.path.abspath
> (to make sure the slashes are the right way round for Windows or Linux)
> and I'm now running it directly in the SConscript instead of as a builder
> since there are no sources for this particular one
> (but there will be for others)
>
> ```
> header = env.subst('${HEADER_BUILD}/mpversion.h')
> header = os.path.normpath(header)
> script = env.subst('${TOP}/py/makeversionhdr.py')
> script = os.path.abspath(script)
> env.Execute(script + ' ' + header, chdir=env.GetLaunchDir())
> ```
>
> I was using File() instead of env.File which is why the variable
> substitution failed from the looks of things
>
>
> On Fri, 7 Sep 2018 at 02:11, Bill Deegan <bill at baddogconsulting.com>
> wrote:
>
>> So much that could be improved with your code example below.
>> Firstly almost no reason to use File() or Dir(), just use a string.
>> Secondly no need to have File(subst...) use File("${TOP}/....")
>>
>> And never have a builder with no sources. If it's no sources that means
>> it can be run when the SConstruct/SConscript is processed, so use  Execute.
>> If it can't be run when SConstruct/SConscripts are processed, then it
>> depends on something, and you should list those as sources.  Your builder
>> can pick and choose what of $SOURCES it uses (or nothing).
>>
>> What directory does your SConstruct live in?
>>
>> -Bill
>>
>> On Thu, Sep 6, 2018 at 7:56 PM RW via Scons-users <scons-users at scons.org>
>> wrote:
>>
>>> I've sorted it out now so no worries, I've also removed the
>>> SConscriptChdir() call
>>>
>>> what I've basically got is
>>> a SConscript within a directory such as
>>> D:\Temp\micropython\ports\minimal
>>> (there being multiple ports under different directories
>>>
>>> This then pulls in a seperate common SConscript under a path such as
>>> D:\Temp\micropython\tools\scons\micropy.py
>>>
>>> via SConscript('../../tools/scons/micropy.py', {'env': env})
>>>
>>> because the common script lives in a different directory I needed to
>>> make sure the paths resolved correctly
>>> Putting in a # at the beginning of the path seems to work best
>>> this way it will resolve to D:\Temp\micropython\ports\minimal instead of
>>> D:\Temp\micropython\tools\scons
>>> which is where the top level script lives
>>>
>>> As a simple extract
>>> ```
>>> # TOP Resolves to D:\Temp\micropython
>>> env.SetDefault(TOP=Dir('../..'))
>>>
>>> env.SetDefault(BUILD='build')
>>> env.Replace(HEADER_BUILD='${BUILD}/genhdr')
>>>
>>> # Build the micropython version header
>>> def build_mpversion(target, source, env):
>>>     # Use File to make sure the directory seperator is the correct way
>>> round
>>>     cmd = File(env.subst('${TOP}/py/makeversionhdr.py')).abspath
>>>     cmd += ' ' + target[0].path
>>>     env.Execute(cmd, chdir=env.GetLaunchDir())
>>>
>>> tgt = env.Command('#${HEADER_BUILD}/mpversion.h', [], build_mpversion)
>>> ```
>>>
>>> Note there's a lot more in this file than just this
>>> and part of the initial exercise is to just try and keep the existing
>>> logic / if statements
>>> from the old Makefile intact to make sure it works before I start to
>>> re-arrange stuff to clean it up
>>>
>>> One thing I have noticed is that if you provide a construction variable
>>> as part of the name to a File or Dir
>>> such as File('${TOP}/py/makeversionhdr.py') then run .abspath on it for
>>> the full path
>>> it doesn't look like it expands out the construction variable
>>>
>>> but this does work
>>> env.Replace(TEST1=Dir('../..'))
>>> env.Replace(TEST2='$TEST1\\additionaldir')
>>> test1 = env.subst('$TEST2')
>>> # test1 now equals D:\Temp\micropython\additionaldir
>>>
>>> On Thu, 6 Sep 2018 at 23:39, Bill Deegan <bill at baddogconsulting.com>
>>> wrote:
>>>
>>>> What command line are you seeing?
>>>> Get rid of your SConscriptChdir() call.
>>>> I never use it.
>>>> You can add as an argument to SConscript, but generally the default
>>>> behavior just works.
>>>>
>>>> Chdir generally breaks parallel builds.
>>>> It's possible the default mentioned in the manpage is incorrect. As far
>>>> as I know all paths are specified from dir and chdir is only done if
>>>> explicitly specified to a builder..
>>>>
>>>> On Thu, Sep 6, 2018 at 5:58 PM Bill Deegan <bill at baddogconsulting.com>
>>>> wrote:
>>>>
>>>>> So you have two builders with empty sources?
>>>>> Not good practice.
>>>>>
>>>>> Use Execute if you want it to always run..
>>>>> -Bill
>>>>>
>>>>> On Thu, Sep 6, 2018 at 5:18 PM RW <garlicbready at googlemail.com> wrote:
>>>>>
>>>>>> Hi Bill,
>>>>>> I think I've figured it out
>>>>>> basically I'm trying to use relative paths which are relative to the
>>>>>> top level SConstruct file
>>>>>> instead of being relative to a second called script in another
>>>>>> directory
>>>>>>
>>>>>> the first way around this is to use the directory parameter
>>>>>> tgt = env.Command(File('testfile.txt', directory ='../src1'), [],
>>>>>> build_test)
>>>>>>
>>>>>> the second way around this is to prefix the path with #
>>>>>> tgt = env.Command(File('#testfile.txt'), [], build_test)
>>>>>>
>>>>>>
>>>>>> On Thu, 6 Sep 2018 at 22:10, Bill Deegan <bill at baddogconsulting.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Perhaps you can explain what you're actually trying to do, rather
>>>>>>> than providing a toy example?
>>>>>>> That will help provide more context correct help.
>>>>>>>
>>>>>>> On Thu, Sep 6, 2018 at 4:23 PM RW via Scons-users <
>>>>>>> scons-users at scons.org> wrote:
>>>>>>>
>>>>>>>> Hi,
>>>>>>>> I've got another question, this is over the use of SConscriptChdir
>>>>>>>> such as env.SConscriptChdir(0)
>>>>>>>> from what I can gather when specifying a File or Dir object or
>>>>>>>> making a call to a Command builder at least which will automatically
>>>>>>>> convert a string target to a File object.
>>>>>>>>
>>>>>>>> The File / Dir object will always be relative to the current
>>>>>>>> SConstruct file.
>>>>>>>> Not relative to the originating SConstruct file (which is what I'm
>>>>>>>> trying to do)
>>>>>>>>
>>>>>>>> To give an example
>>>>>>>>
>>>>>>>> src1\test1.txt - empty test file
>>>>>>>> src1\test2.txt - empty test file
>>>>>>>>
>>>>>>>> src1\SConstruct
>>>>>>>> ```
>>>>>>>> import os
>>>>>>>>
>>>>>>>> EnsureSConsVersion(3, 0, 0)
>>>>>>>>
>>>>>>>> # Setup the construction env
>>>>>>>> env = Environment(ENV={'PATH': os.environ['PATH']})
>>>>>>>>
>>>>>>>> # Set working directory to not change
>>>>>>>> env.SConscriptChdir(0)
>>>>>>>>
>>>>>>>> # Load in an external script
>>>>>>>> SConscript('../src2/testsubscript.py', {'env': env})
>>>>>>>> ```
>>>>>>>>
>>>>>>>> src2\SConstruct
>>>>>>>> ```
>>>>>>>> # Import the scons environment from the calling script
>>>>>>>> Import('env')
>>>>>>>>
>>>>>>>> def build_test(target, source, env):
>>>>>>>>     # At this point the 'testfile.txt' will be automatically
>>>>>>>> changed to a File class by SCons
>>>>>>>>
>>>>>>>>     # print the path scons thinks this file is located at
>>>>>>>>     print(target[0].path)
>>>>>>>>
>>>>>>>> tgt = env.Command(File('testfile.txt'), [], build_test)
>>>>>>>> env.Default(tgt)
>>>>>>>>
>>>>>>>> tgt2 = env.Command('testfile2.txt', [], build_test)
>>>>>>>> env.Default(tgt2)
>>>>>>>>
>>>>>>>> # Even though SConscriptChdir is set to 0 in the originating env,
>>>>>>>> File uses the current script as it's reference point
>>>>>>>> # D:\Temp\testproject\src2\testfile.txt
>>>>>>>> # D:\Temp\testproject\src2\testfile2.txt
>>>>>>>> ```
>>>>>>>>
>>>>>>>> Is this expected behaviour?
>>>>>>>> perhaps SConscriptChdir only influences when calling exe's rather
>>>>>>>> than the use of File or Dir
>>>>>>>> is there some public API way of setting the current directory for
>>>>>>>> File / Dir calls?
>>>>>>>> thats not the directory of the current SConsscript
>>>>>>>> since builders wrap everything in a File automatically, it might
>>>>>>>> mean I have to make sure all file paths are absolute before hand.
>>>>>>>>
>>>>>>>> Many Thanks
>>>>>>>> Richard
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> Scons-users mailing list
>>>>>>>> Scons-users at scons.org
>>>>>>>> https://pairlist4.pair.net/mailman/listinfo/scons-users
>>>>>>>>
>>>>>>> _______________________________________________
>>> Scons-users mailing list
>>> Scons-users at scons.org
>>> https://pairlist4.pair.net/mailman/listinfo/scons-users
>>>
>> _______________________________________________
> Scons-users mailing list
> Scons-users at scons.org
> https://pairlist4.pair.net/mailman/listinfo/scons-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://pairlist4.pair.net/pipermail/scons-users/attachments/20180906/ceddde56/attachment.html>