aea747a1ad
1 Commits
Author | SHA1 | Message | Date | |
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Luca Ceresoli
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c2d80a8c5d |
core: don't build host-cmake if it is available on the build host
Currently all cmake packages depend on host-cmake. Unfortunately
host-cmake takes a long time to configure and build: almost 7 minutes
on a dual-core i5 with SSD. The time does not change even with ccache
enabled.
Indeed, building host-cmake is avoidable if it is already installed on
the build host: CMake is supposed to be quite portable, and the only
patch in Buildroot for the CMake package seems to only affect
target-cmake.
Thus we automatically skip building host-cmake and use the one on the
system if:
- cmake is available on the system and
- it is recent enough.
First, we leverage the existing infrastructure in
support/dependencies/dependencies.mk to find out whether there's a
suitable cmake executable on the system. Its path can be passed in the
BR2_CMAKE environment variable, otherwise it defaults to "cmake". If
it is enabled, found and suitable then we set BR2_CMAKE_HOST_DEPENDENCY
to empty; otherwise we set BR2_CMAKE_HOST_DEPENDENCY to 'host-cmake' and
override BR2_CMAKE with "$(HOST_DIR)/usr/bin/cmake" to revert to using
our own cmake (the old behaviour).
Then in pkg-cmake.mk we replace the hard-coded dependency on host-cmake
to using the BR2_CMAKE_HOST_DEPENDENCY variable, and we use $(BR2_CMAKE)
instead of $(HOST_DIR)/usr/bin/cmake.
Unlike what we do for host-tar and host-xzcat, for host-cmake we do
not add host-cmake to DEPENDENCIES_HOST_PREREQ. If we did, host-cmake
would be a dependency for _any_ package when it's not installed on the
host, even when no cmake package is selected.
Cmake versions older than 3.0 are affected by the bug described and
fixed in Buildroot in
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