What do you think about the new patch I attached to this mail? It adds an option NATIVE_DIR_TOKENS to ExternalProjects_Add. I also attached a CMake script file which tests/shows this feature.
Stefan Kislinskiy
________________________________________
Von: cmake-developers [cmake-developers-boun...@cmake.org] im Auftrag von David
Cole via cmake-developers [cmake-developers@cmake.org]
Gesendet: Donnerstag, 20. August 2015 23:20
An: James Johnston
Cc: cmake-developers@cmake.org
Betreff: Re: [cmake-developers] ExternalProject: Use native paths as substitute
for directory tokens
It's exactly what I am concerned about:
You're asking to change the behavior of something for EVERYONE to
solve a problem which you have encountered. If you change it the way
you have proposed, you will cause problems for others. It has worked
the way it is now since ExternalProject_Add was introduced in CMake
2.8. Changing it unconditionally the way you propose is simply not
feasible for backwards compatibility.
I think commands that take native paths ought NOT to use the <*_DIR>
replacement values, and instead, ought to pass in variables that
contain the native paths in the first place.
David C.
On Thu, Aug 20, 2015 at 2:58 PM, James Johnston
<johnstonj.pub...@codenest.com> wrote:
> Hi,
>
> Funny you are mailing the list about this, since I just ran into this same
> issue today building something totally different from Boost... In this case
> it's a build tool that thinks the "/U" in "C:/Users" is a new command line
> argument, that isn't recognized - and then the subsequent "s" also ends up
> unrecognized... and it all fails... And it has nothing to do with the
> working directory, so _Add_Step(WORKING_DIRECTORY) isn't a possible
> workaround for me.
>
> I think the issue with globally making this change to the existing tokens is
> that there could be some external tool/program that is EXPECTING to get CMake
> paths, not native paths. Who knows? I am guessing that is what David Cole
> was concerned about.
>
> Maybe the right answer is to introduce some NEW tokens while leaving the
> behavior of the old ones unchanged. E.g. <BINARY_DIR_NATIVE> etc. It would
> be good if the patch updates the documentation of ExternalProject and clearly
> states the path format of <BINARY_DIR> vs <BINARY_DIR_NATIVE>. Then the user
> can pick whichever one suits them best, depending on the tool being invoked.
>
> Furthermore, sometimes <BINARY_DIR_NATIVE> still needs to be replaced with a
> CMake path, not native path. For example, if the token is being found in a
> property like WORKING_DIRECTORY that eventually gets passed to
> add_custom_command(WORKING_DIRECTORY) then I'm guessing still has to be a
> CMake path. I am guessing this is what David Cole was also concerned about.
>
> I still think your original method of building Boost is a bit unusual and
> would be better served by _Add_Step with a custom working directory - because
> that's the publicly documented/standard way of changing the working
> directory, but that is up to you. :)
>
> Best regards,
>
> James Johnston
>
>
> ---- On Thu, 20 Aug 2015 14:37:08 +0000 Stefan Kislinskiy
> <s.kislins...@dkfz-heidelberg.de> wrote ----
>
> > Hi,
> >
> > thank you for our suggestions. I am aware that I can solve my example
> differently and that it might look not directly connected the proposal, but
> well, it is an example just to show a single case and why it matters. :) I
> did not want to discuss the example itself. Working around here would just
> resolve a symptom.
> >
> > My point is the overall problem that would persist: A big part of
> ExternalProject is to issue commands for predefined and custom steps. Those
> commands are supposed to be executed by the shell/command line. According to
> the documentation and the source code of ExternalProject, directory tokens
> are mainly supposed to be replaced in commands. It is my understanding, that
> it is a bug, if CMake isn't able to assemble these commands correctly. This
> would include usage of the correct path style of the OS for shell/command
> line commands. As directory tokens are replaced internally right before a
> shell/command line command is assembled, I can't see why this would be kind
> of "API-breaking". You cannot interfere in your CMake code with these
> internal replacements.
> >
> > Therefore I would still prefer my solution as it is pretty simple without
> adding even more features to ExternalProject and in my opinion without
> breaking code in the wild. It is a true bug fix instead of a feature request
> for working directories, which is a different topic that just coincidentally
> arised because of my specific example I guess. The features you described
> wouldn't fix the actual bug.
> >
> > As you were not sure if my approach would even fix my problems: It does of
> course and this is what I am currently doing and what I tested extensively
> before creating the patch. :) Regarding your quote from the
> add_custom_command documentation I can tell you that this is how things are
> currently done in ExternalProject and always were as far as I know, for
> example (from ExternalProject.cmake):
> >
> > add_custom_command(
> > OUTPUT ${stamp_file}
> > BYPRODUCTS ${byproducts}
> > COMMENT ${comment}
> > COMMAND ${command}
> > COMMAND ${touch}
> > DEPENDS ${depends}
> > WORKING_DIRECTORY ${work_dir}
> > VERBATIM
> > )
> >
> > Best regards,
> > Stefan
> >
> >
> > -----Original Message-----
> > From: cmake-developers [mailto:cmake-developers-boun...@cmake.org] On
> Behalf Of James Johnston
> > Sent: Donnerstag, 20. August 2015 15:37
> > To: cmake-developers@cmake.org
> > Subject: Re: [cmake-developers] ExternalProject: Use native paths as
> substitute for directory tokens
> >
> > > -----Original Message-----
> > > From: cmake-developers [mailto:cmake-developers-boun...@cmake.org]
> > > On Behalf Of Kislinskiy, Stefan
> > > Sent: Thursday, August 20, 2015 09:02
> > > To: David Cole
> > > Cc: cmake-developers@cmake.org
> > > Subject: Re: [cmake-developers] ExternalProject: Use native paths as
> > > substitute for directory tokens
> > >
> > > Hi David,
> > >
> > > Example excerpt (it is not possible to change the working directory
> > > for
> > the
> > > CONFIGURE_COMMAND as it is fixed to the BUILD_DIR, which might not be
> > > sufficient):
> >
> > This doesn't really directly have to do with your proposal, but what if an
> option was added to change the working dir of the CONFIGURE_COMMAND? E.g.
> > WORKING_DIRECTORY_CONFIGURE. And suppose you'd have it recognize the
> various tags like <SOURCE_DIR>, etc. This might be useful to add to other
> steps as well, and would be more portable than your solution which is using
> cmd.exe-specific commands. You'd want to audit for any resulting breakage
> (e.g. does ExternalProject make assumptions that the working directory of
> CONFIGURE is always the binary dir? - e.g. a relative path being used
> somewhere. And probably only allow specification of
> WORKING_DIRECTORY_CONFIGURE if a CONFIGURE_COMMAND was also specified, as the
> built-in commands certainly assume the default working dir.)
> >
> > In your situation though, I'm not sure it's strictly needed. From your
> sample, it looks like you're building boost. In your case what if you:
> >
> > * Use ExternalProject_Add_Step to bootstrap. You can specify a
> WORKING_DIRECTORY here. Note one problem: you can't do out of source build
> of b2, which breaks user expectations.
> > * Then use ExternalProject_Add_Step to build Boost.
> >
> > Yes, using _Add_Step is somewhat of a workaround, but in this case, I've
> found it wasn't much of a burden at all. In fact the only case I can think
> of where it WOULD be a burden would be if the configure step is CMake. But
> then you wouldn't need to change the working directory; changing it would
> break CMake. In practice nobody will want to change WORKING_DIRECTORY unless
> it's a custom command and then it's easy to use _Add_Step anyway.
> > That said, it might still be considered a little undesired and so maybe my
> proposal above would be a better way to handle it.
> >
> > Corrections from maintainers and others on the above commentary are
> welcome...
> >
> > >
> > > set(bootstrap_cmd "<SOURCE_DIR>/bootstrap${shell_ext}"
> > > ${bootstrap_toolset})
> > >
> > > if(WIN32)
> > > set(bootstrap_cmd pushd "<SOURCE_DIR>" COMMAND ${bootstrap_cmd}
> > > COMMAND popd)
> > > endif()
> > >
> > > ExternalProject_Add(Boost
> > > ...
> > > CONFIGURE_COMMAND ${bootstrap_cmd}
> > > ...
> > > )
> >
> > From add_custom_command: "If more than one COMMAND is specified they will
> be executed in order, but not necessarily composed into a stateful shell or
> batch script."
> >
> > So I am not sure your approach will work for you even if you fix the issue
> with path slashes.
> >
> > James
> >
>
> --
>
> Powered by www.kitware.com
>
> Please keep messages on-topic and check the CMake FAQ at:
> http://www.cmake.org/Wiki/CMake_FAQ
>
> Kitware offers various services to support the CMake community. For more
> information on each offering, please visit:
>
> CMake Support: http://cmake.org/cmake/help/support.html
> CMake Consulting: http://cmake.org/cmake/help/consulting.html
> CMake Training Courses: http://cmake.org/cmake/help/training.html
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/cmake-developers
--
Powered by www.kitware.com
Please keep messages on-topic and check the CMake FAQ at:
http://www.cmake.org/Wiki/CMake_FAQ
Kitware offers various services to support the CMake community. For more
information on each offering, please visit:
CMake Support: http://cmake.org/cmake/help/support.html
CMake Consulting: http://cmake.org/cmake/help/consulting.html
CMake Training Courses: http://cmake.org/cmake/help/training.html
Visit other Kitware open-source projects at
http://www.kitware.com/opensource/opensource.html
Follow this link to subscribe/unsubscribe:
http://public.kitware.com/mailman/listinfo/cmake-developers
native_dir_tokens.patch
Description: native_dir_tokens.patch
cmake_minimum_required(VERSION 3.3.1 FATAL_ERROR)
project(Test VERSION 0.0.0.0 LANGUAGES NONE)
set(CMAKE_MODULE_PATH ".../cmake/Modules") # Adjust path to modified
ExternalProject.cmake file
include(ExternalProject)
ExternalProject_Add(CMakeStyle
SOURCE_DIR ${CMAKE_BINARY_DIR}
CONFIGURE_COMMAND echo <SOURCE_DIR>
BUILD_COMMAND echo <BINARY_DIR>
INSTALL_COMMAND echo <INSTALL_DIR>
)
ExternalProject_Add_Step(CMakeStyle custom
COMMAND echo <TMP_DIR>
DEPENDERS configure
)
ExternalProject_Add(ExplicitCMakeStyle
SOURCE_DIR ${CMAKE_BINARY_DIR}
CONFIGURE_COMMAND echo <SOURCE_DIR>
BUILD_COMMAND echo <BINARY_DIR>
INSTALL_COMMAND echo <INSTALL_DIR>
NATIVE_DIR_TOKENS 0
)
ExternalProject_Add_Step(ExplicitCMakeStyle custom
COMMAND echo <TMP_DIR>
DEPENDERS configure
)
ExternalProject_Add(NativeStyle
SOURCE_DIR ${CMAKE_BINARY_DIR}
CONFIGURE_COMMAND echo <SOURCE_DIR>
BUILD_COMMAND echo <BINARY_DIR>
INSTALL_COMMAND echo <INSTALL_DIR>
NATIVE_DIR_TOKENS 1
)
ExternalProject_Add_Step(NativeStyle custom
COMMAND echo <TMP_DIR>
DEPENDERS configure
)
-- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake-developers
