The example shown on https://crascit.com/2016/04/09/using-ccache-with-cmake/ <https://crascit.com/2016/04/09/using-ccache-with-cmake/> is for Xcode. Hence setting the CMAKE_XCODE_ATTRIBUTE… variables. On Linux, what are these variables? Are they CMAKE_ATTRIBUTE… without XCODE?
> On Jan 19, 2017, at 2:11 PM, Craig Scott <craig.sc...@crascit.com> wrote: > > Ah, sorry, I misunderstood what CCACHE_DIR was for. Nevertheless, the method > in that linked article could be easily modified to do what you want. Simply > add the setting of the environment variable to the launch scripts. Since > those launch scripts are copied across to the build dir at configure time and > they support variable substitutions, you can even have the value of > CCACHE_DIR be settable from CMake if you want. For example, your launch-c.in > <http://launch-c.in/> file could look like this: > > #!/bin/sh > export CCACHE_CPP2=true > export CCACHE_DIR=${CCACHE_DIR} > exec "${RULE_LAUNCH_COMPILE}" "${CMAKE_C_COMPILER}" "$@" > When you run CMake, it substitutes the value of each of the above variables > as they are set when the configure_file() command is called. Therefore, the > configure step bakes in the value of CCACHE_DIR and it won't need to be set > in your environment when you do the build step. Note that the substitutions > are substituting CMake variables, not environment variables, so if you wanted > to pass through a CCACHE_DIR environment variable instead, you would do > something like this: > > #!/bin/sh > export CCACHE_CPP2=true > export CCACHE_DIR=$ENV{CCACHE_DIR} > exec "${RULE_LAUNCH_COMPILE}" "${CMAKE_C_COMPILER}" "$@" > Probably better to do that in your CMakeLists.txt instead though and leave > the launch-c.in <http://launch-c.in/> script as in the first case above. This > would mean your CMakeLists.txt would have a line like this somewhere: > > set(CCACHE_DIR $ENV{CCACHE_DIR}). > > Note, however, that relying on environment variables for configure or build > steps is not so robust. If, for example, you change a CMakeLists.txt file or > something else in your project requires CMake to be re-run, then CMake can > re-run as part of a build. This then means the environment variables have to > be the same between your CMake runs and your build runs. That's normally not > a problem for most people, but thought I'd mention it just in case. > Personally, I try to avoid relying on environment variables and instead have > such values passed in as CMake cache variables like so: > > cmake -G Ninja -DCCACHE_DIR=${CCACHE_DIR} ../src > > This saves the value in the cache and then it is preserved regardless of what > environment I have when I do subsequent build steps. > > > > > On Fri, Jan 20, 2017 at 7:44 AM, David Lind <davidkl...@gmail.com > <mailto:davidkl...@gmail.com>> wrote: > Scott, > > I have find_program implemented to find ccache, as shown below. > > find_program(CCACHE ccache) > if(CCACHE) > set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ${CCACHE}) > set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK ${CCACHE}) > endif() > > That’s not the issue. The issue is telling ccache where to place it’s cache > files. If I compiles for toolchain X, Y and X, I need to set CCACHE_DIR > accordingly. Otherwise the cache will be useless. > > —Dave > >> On Jan 19, 2017, at 12:57 PM, Craig Scott <craig.sc...@crascit.com >> <mailto:craig.sc...@crascit.com>> wrote: >> >> Rather than relying on environment variables, you can use CMake's >> find_program() command to find ccache on your path and then tell CMake to >> use that as a launcher. You can find an article with a detailed explanation >> of how to set this up here: >> >> https://crascit.com/2016/04/09/using-ccache-with-cmake/ >> <https://crascit.com/2016/04/09/using-ccache-with-cmake/> >> >> An advantage of this approach is that the build will work with or without >> ccache installed. We've been using this in production for some time now and >> it works very smoothly. The technique can probably also be extended to >> support Windows too with clcache <https://github.com/frerich/clcache>, but I >> haven't tried that yet. >> >> >> On Fri, Jan 20, 2017 at 5:00 AM, David Lind <davidkl...@gmail.com >> <mailto:davidkl...@gmail.com>> wrote: >> I am porting existing makefiles to cmake. One of the key features of these >> makefiles is setting the CCACHE_DIR environment variable based upon the tool >> chain selected. >> >> I have TC_<toolchain>.cmake files created. Ideally, I would add a line to >> these files to set the CCACHE_DIR. But, CMake doesn’t have the ability to >> set environment variables during the build step. So, I’m stuck. >> >> Has anyone encountered this kind of situation? >> >> —Dave >> -- >> >> Powered by www.kitware.com <http://www.kitware.com/> >> >> Please keep messages on-topic and check the CMake FAQ at: >> http://www.cmake.org/Wiki/CMake_FAQ <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 >> <http://cmake.org/cmake/help/support.html> >> CMake Consulting: http://cmake.org/cmake/help/consulting.html >> <http://cmake.org/cmake/help/consulting.html> >> CMake Training Courses: http://cmake.org/cmake/help/training.html >> <http://cmake.org/cmake/help/training.html> >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> <http://www.kitware.com/opensource/opensource.html> >> >> Follow this link to subscribe/unsubscribe: >> http://public.kitware.com/mailman/listinfo/cmake >> <http://public.kitware.com/mailman/listinfo/cmake> >> >> >> -- >> Craig Scott >> Melbourne, Australia >> https://crascit.com <https://crascit.com/> > > > > > -- > Craig Scott > Melbourne, Australia > https://crascit.com <https://crascit.com/>
-- 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
