[Buildroot] [PATCH 05/14] pkg-cmake.mk: enable ccache for cmake packages

[Arnout Vandecappelle <arnout@mind.be>]

On 24/04/14 00:48, Samuel Martin wrote:
> This patch updates the generated toolchainfile.cmake to use ccache.
> 
> When toolchainfile.cmake is used inside Buildroot, using ccache during
> the build is driven by a CMake knob: USE_CCACHE, automatically set by
> the cmake-package infrastructure and reflecting the BR2_CCACHE value.
> 
> Since this toolchainefile.cmake file can be used outside Buildroot, and
> this file also set a couple of things (among these: the sysroot cflag,
> some pkg-config environment variables), it is important to set the
> compiler variables as well to keep the consistency of the
> cross-compilation configuration.
> So, when it is used outside Buildroot, using ccache for the build is
> driven by the ccache program availability.

 I don't understand this. We can just use br-ccache when it's called from
outside buildroot as well, no?


> 
> Note that using ccache for the build is achieved by setting the *_ARG1
> CMake variables to let CMake use ccache without failing in detecting
> the compiler.
> 
> Signed-off-by: Samuel Martin <s.martin49@gmail.com>
> Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
> Cc: Luca Ceresoli <luca@lucaceresoli.net>
> 
> ---
> changes v2 -> v3 (Samuel):
> - rebase
> - inline the -DUSE_CCACHE=... in the configure commands.
> - always set the compiler variables, even when called for outside
>   Buildroot.
> - update commit message
> 
> changes v1 -> v2 (Luca):
> - totally reimplemented based on Samuel's suggestion;
> - added dependency on host-ccache for cmake packages if ccache is
>   enabled.
> ---
>  package/pkg-cmake.mk | 35 +++++++++++++++++++++++++++++++++--
>  1 file changed, 33 insertions(+), 2 deletions(-)
> 
> diff --git a/package/pkg-cmake.mk b/package/pkg-cmake.mk
> index b2ac2df..a032426 100644
> --- a/package/pkg-cmake.mk
> +++ b/package/pkg-cmake.mk
> @@ -66,6 +66,7 @@ define $(2)_CONFIGURE_CMDS
>  		-DCMAKE_INSTALL_PREFIX="/usr" \
>  		-DCMAKE_COLOR_MAKEFILE=OFF \
>  		-DBUILD_SHARED_LIBS=$(if $(BR2_PREFER_STATIC_LIB),OFF,ON) \
> +		-DUSE_CCACHE=$(if $(BR2_CCACHE),ON,OFF) \
>  		$$($$(PKG)_CONF_OPT) \
>  	)
>  endef
> @@ -83,6 +84,7 @@ define $(2)_CONFIGURE_CMDS
>  		-DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY="BOTH" \
>  		-DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE="BOTH" \
>  		-DCMAKE_INSTALL_PREFIX="$$(HOST_DIR)/usr" \
> +		-DUSE_CCACHE=$(if $(BR2_CCACHE),ON,OFF) \
>  		$$($$(PKG)_CONF_OPT) \
>  	)
>  endef
> @@ -161,8 +163,6 @@ host-cmake-package = $(call inner-cmake-package,host-$(pkgname),$(call UPPERCASE
>  define TOOLCHAINFILE_CMAKE
>  string(REPLACE /usr/share/buildroot "" _HOST_DIR $${CMAKE_CURRENT_LIST_DIR})
>  set(CMAKE_SYSTEM_NAME Linux)
> -set(CMAKE_C_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> -set(CMAKE_CXX_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))g++)
>  set(CMAKE_C_FLAGS "$${CMAKE_C_FLAGS} $(TARGET_CFLAGS)" CACHE STRING "Buildroot CFLAGS" FORCE)
>  set(CMAKE_CXX_FLAGS "$${CMAKE_CXX_FLAGS} $(TARGET_CXXFLAGS)" CACHE STRING "Buildroot CXXFLAGS" FORCE)
>  set(CMAKE_INSTALL_SO_NO_EXE 0)
> @@ -172,6 +172,37 @@ set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
>  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
>  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
>  set(ENV{PKG_CONFIG_SYSROOT_DIR} $${_HOST_DIR}/$(STAGING_SUBDIR))
> +# This toolchain file can be used both inside and outside Buildroot.
> +# * When used inside Buildroot, ccache support is explicitly driven using the
> +#   USE_CCACHE variable.
> +# * When used outside Buildroot (i.e. when USE_CCACHE is not defined), ccache
> +#   support is automatically enabled if the ccache program is available.
> +if(DEFINED USE_CCACHE)
> +	if(USE_CCACHE)
> +		set(CMAKE_ASM_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> +		set(CMAKE_C_COMPILER $${_HOST_DIR}/usr/bin/ccache)
> +		set(CMAKE_CXX_COMPILER $${_HOST_DIR}/usr/bin/ccache)
> +		set(CMAKE_C_COMPILER_ARG1 $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> +		set(CMAKE_CXX_COMPILER_ARG1 $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))g++)
> +	else()
> +		set(CMAKE_C_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> +		set(CMAKE_CXX_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))g++)
> +	endif()

 I don't see why this USE_CCACHE condition should be dynamic. If
BR2_CCACHE is set, then we can _always_ use ccache, no? So:

ifeq($(BR2_CCACHE),y)
define TOOLCHAINFILE_CMAKE_CCACHE
set(CMAKE_C_COMPILER $${_HOST_DIR}/usr/bin/ccache)
set(CMAKE_CXX_COMPILER $${_HOST_DIR}/usr/bin/ccache)
...
endef
else # BR2_CCACHE
define TOOLCHAINFILE_CMAKE_CCACHE
...
endef
endif


> +else()
> +	find_program(CCACHE ccache)

 Note that if we don't set PATH explicitly to point to the host dir, this
will point to the system's ccache instead of buildroot ccache.


 Regards,
 Arnout


> +	if(CCACHE)
> +		set(CMAKE_ASM_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> +		set(CMAKE_C_COMPILER $${CCACHE})
> +		set(CMAKE_CXX_COMPILER $${CCACHE})
> +		set(CMAKE_C_COMPILER_ARG1 $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> +		set(CMAKE_CXX_COMPILER_ARG1 $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))g++)
> +		message(STATUS "ccache program has been found and will be used for the build.")
> +		message(STATUS "  To disable ccache, add -DUSE_CCACHE=OFF on the cmake command line.")
> +	else()
> +		set(CMAKE_C_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))gcc)
> +		set(CMAKE_CXX_COMPILER $(subst $(HOST_DIR),$${_HOST_DIR},$(TARGET_CROSS))g++)
> +	endif()
> +endif()
>  endef
>  
>  $(HOST_DIR)/usr/share/buildroot/toolchainfile.cmake:
> 


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
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