Add custom commands to CMakeLists.txt file - cmake

Recently I have switched my project compilation procedure from make to cmake. I would like to add custom non-compilation related commands to my CMakeLists.txt file. These commands should be inherited from classical Makefile. Commands that I would like to re-use in CMakeLists.txt are:
CODE=main
ARCHIVE=$(CODE)_`date +%F`.tar.bz2
BACKUP=$(HOME)/backup/src/$(CODE)
run:
{ time ./$(CODE); } 2> $(CODE)_time
rerun: fresh run
fresh:
rm -rvf $(CODE)_time *~ fort.* *.ver
rm -rvf coef? enc skin_depths log input_params.out
clean: fresh
rm -rvf $(CODE) *.o *.a *.mod
backup: *
tar -cjvf $(ARCHIVE) $?
tar -tjvf $(ARCHIVE)
mv -vf $(ARCHIVE) $(BACKUP)
ls -lrth $(BACKUP)
How may I transfer these commands to CMakeLists.txt so that they will be automatically inserted into cmake generated Makefile?
CMakeLists.txt
# Minimum cmake version
cmake_minimum_required(VERSION 2.8)
# Project name
project(main Fortran)
# Toolchain selection, possible arguments: Intel, GNU
SET(Toolchain GNU)
# Compiler selection
include(CMakeForceCompiler)
# GNU compilers
if(${Toolchain} MATCHES GNU)
CMAKE_FORCE_Fortran_COMPILER(gfortran "GNU Fortran Compiler")
set(CMAKE_Fortran_FLAGS "-g -O0 -fimplicit-none -fbounds-check -fbacktrace ${CMAKE_Fortran_FLAGS}")
endif(${Toolchain} MATCHES GNU)
# Source code files
SET(src variables.F90
init.F90
io.F90)
# Main executable
ADD_EXECUTABLE(${PROJECT_NAME} ${src})
# EoF: CMakeLists.txt

Use the ADD_CUSTOM_TARGET and/or ADD_CUSTOM_COMMAND commands, e.g.:
ADD_CUSTOM_TARGET(myTarget
COMMAND firstCommand arg1 arg2
COMMAND secondCommand arg1 arg2 arg3)
Then you can use make myTarget.

Related

How to copy linked and mingw libs to output dir of executable?

I'm new in CMake.
Could someone please describe to me what I should write in my CMakeLists.txt to copy dependencies to the output directory of the executable file?
So, I have a CMake project:
# top-level CMakeLists.txt
cmake_minimum_required(VERSION 3.23)
project(CoolLib VERSION 0.0.1)
set(CMAKE_CXX_STANDARD 23)
add_subdirectory(mylib)
add_subdirectory(mytestconsole)
install(TARGETS mnconsole mnlib
RUNTIME DESTINATION bin COMPONENT Runtime
LIBRARY DESTINATION lib COMPONENT Runtime
ARCHIVE DESTINATION lib/myproject COMPONENT Development)
# mylib/CMakeLists.txt
cmake_minimum_required(VERSION 3.23)
project(mylib VERSION 0.0.1)
add_library(mylib SHARED mylib.cpp mylib.h)
target_include_directories(mylib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
# mytestconsole/CMakeLists.txt
cmake_minimum_required(VERSION 3.23)
project(mytestconsole VERSION 0.0.1)
add_executable(mytestconsole main.cpp)
target_link_libraries(mytestconsole LINK_PUBLIC mylib)
target_include_directories(mytestconsole PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_SOURCE_DIR}/mylib)
As you can see, I've added an install() command, but this isn't exactly what I want.
As far as I understand, the install() command will copy my program to the Program Files directory in Windows.
GOAL:
I want to copy the mingw libraries (e.g. libgcc_s_seh-1, libstdc++-6, libwinpthread-1, etc.) and mylib to the output directory of the mytestconsole.exe file.
PS: I saw this answer, but GetPrerequesites is deprecated. And I didn't understand how to use it.
I tried to do this:
add_custom_command(
TARGET mnconsole POST_BUILD
COMMAND LIST_PREREQUISITES($<TARGET_FILE:mnconsole>)
VERBATIM)
But got an error:
D:\Programs\JetBrains\CLion\bin\cmake\win\bin\cmake.exe --build D:\Projects\MethaneNumber\_builds\debug --target mnconsole -j 9
[1/1] Linking CXX executable mnconsole\mnconsole.exe
FAILED: mnconsole/mnconsole.exe
cmd.exe /C "cd . && D:\Programs\mingw64\12.2.0\x64\posix-seh\bin\c++.exe -g mnconsole/CMakeFiles/mnconsole.dir/main.cpp.obj -o mnconsole\mnconsole.exe -Wl,--out-implib,mnconsole\libmnconsole.dll.a -Wl,--major-image-version,0,--minor-image-version,0 mnlib/libmnlib.a -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 && cmd.exe /C "cd /D D:\Projects\MethaneNumber\_builds\debug\mnconsole && LIST_PREREQUISITES ( D:/Projects/MethaneNumber/_builds/debug/mnconsole/mnconsole.exe )""
"LIST_PREREQUISITES" is ­not recognized as an internal command.
ninja: build stopped: subcommand failed.
PS2: It should work like windeployqt.exe with Qt, but I'm not using Qt in this project right now.

Using GLSLC's depfile to make included files automatically trigger recompile of SPIRV in CMake

I'm trying to create a cmake function that automatically recompiles glsl to spirv upon changes to the shader files. Right now direct dependencies work, ie the shaders I use as compile arguments. However I make heavy use of #include feature that glslc provides, and by default I can't get changes in that stuff to trigger recompile. I made sure that I'm using the Ninja
Right now I have the following CMake function and arguments:
cmake -DCMAKE_BUILD_TYPE=Debug "-DCMAKE_MAKE_PROGRAM=JETBRAINSPATH/bin/ninja/win/ninja.exe" -G Ninja "PATH_TO_CURRENT_DIRECTORY"
function
set(GLSLC "$ENV{VULKAN_SDK}/Bin/glslc")
function(target_shader_function SHADER_TARGET)
foreach (SHADER_SOURCE_FILEPATH ${ARGN})
get_filename_component(SHADER_SOURCE_FILENAME ${SHADER_SOURCE_FILEPATH} NAME)
get_filename_component(SHADER_SOURCE_DIRECTORY ${SHADER_SOURCE_FILEPATH} DIRECTORY)
set(SHADER_TARGET_NAME "${SHADER_TARGET}_${SHADER_SOURCE_FILENAME}")
set(SHADER_BINARY_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/spirv")
set(SHADER_FINAL_BINARY_FILEPATH "${SHADER_BINARY_DIRECTORY}/${SHADER_SOURCE_FILENAME}.spv")
#we can use depfiles instead
#https://stackoverflow.com/questions/60420700/cmake-invocation-of-glslc-with-respect-to-includes-dependencies
add_custom_command(
OUTPUT ${SHADER_FINAL_BINARY_FILEPATH}
DEPENDS ${SHADER_SOURCE_FILEPATH}
DEPFILE ${SHADER_SOURCE_FILEPATH}.d
COMMAND ${CMAKE_COMMAND} -E make_directory ${SHADER_BINARY_DIRECTORY}
COMMAND ${GLSLC} -MD -MF ${SHADER_SOURCE_FILEPATH}.d -O ${SHADER_SOURCE_FILEPATH} -o ${SHADER_FINAL_BINARY_FILEPATH} --target-env=vulkan1.2 -I ${CMAKE_SOURCE_DIR}/shaderutils
DEPENDS ${SHADER_SOURCE_FILEPATH}
# BYPRODUCTS ${SHADER_FINAL_BINARY_FILEPATH} ${SHADER_SOURCE_FILEPATH}.d causes ninja to no longer work
COMMENT "Compiling SPIRV for \nsource: \n\t${SHADER_SOURCE_FILEPATH} \nbinary: \n\t${SHADER_FINAL_BINARY_FILEPATH} \n"
)
add_custom_target(${SHADER_TARGET_NAME} DEPENDS ${SHADER_FINAL_BINARY_FILEPATH} ${SHADER_SOURCE_FILEPATH}.d)
add_dependencies(${SHADER_TARGET} ${SHADER_TARGET_NAME})
endforeach (SHADER_SOURCE_FILEPATH)
endfunction()
and I use it like this:
cmake_minimum_required(VERSION 3.21)
cmake_policy(SET CMP0116 NEW)
project(my_workspace)
add_executable(my_target main.cpp)
...
target_shader_function(my_target
${CMAKE_CURRENT_SOURCE_DIR}/shaders/example.comp
)
main.cpp
#include <iostream>
int main(){
std::cout << "hello world!" << std::endl;
return 0;
}
Again, everything works fine if I change, for example, example.comp.
However, lets say I have the following shader (lets say that this is example.comp):
#version 460
#include "fooutils.glsl"
#define WORKGROUP_SIZE 1024
layout (local_size_x = WORKGROUP_SIZE, local_size_y = 1, local_size_z = 1) in;
layout(set = 0, binding = 0) buffer MyBufferBlock{
float data[];
}
void main(){
uint tidx = gl_GlobalInvocationID.x;
data[tidx] += foo(tidx);
}
and I include the following:
#ifndef FOOUTILS_GLSL
#define FOOUTILS_GLSL
float foo(uint tidx){
return mod(tidx, 4.51);
}
#endif //FOOUTILS_GLSL
and I change fooutils.glsl after everything is compiled once (for example in a way that stops it from compiling),
#ifndef FOOUTILS_GLSL
#define FOOUTILS_GLSL
float foo(uint tidx){
return x;
return mod(tidx, 4.51);
}
#endif //FOOUTILS_GLSL
I don't get a recompile triggered. I had assumed that ninja would use this info to accomplish this, but I haven't seen it happen.
How do I use this depfile to force a recompile when an include dependency changes?
Here's my working implementation. But first, here's my terminal output so you can see it's working:
$ tree
.
├── CMakeLists.txt
├── main.cpp
├── shaders
│   └── example.comp
└── shaderutils
└── fooutils.glsl
$ cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
...
$ cmake --build build/
[1/3] Compiling SPIRV: shaders/example.comp -> spirv/example.spv
[2/3] Building CXX object CMakeFiles/my_target.dir/main.cpp.o
[3/3] Linking CXX executable my_target
$ cmake --build build/
ninja: no work to do.
$ touch shaderutils/fooutils.glsl
$ cmake --build build/
[1/1] Compiling SPIRV: shaders/example.comp -> spirv/example.spv
$ cat build/spirv/example.d
spirv/example.spv: /path/to/shaders/example.comp /path/to/shaderutils/fooutils.glsl
$ cat build/CMakeFiles/d/*.d
spirv/example.spv: \
../shaders/example.comp \
../shaderutils/fooutils.glsl
Now on to the implementation
cmake_minimum_required(VERSION 3.22)
project(test)
function(target_shader_function TARGET)
find_package(Vulkan REQUIRED)
if (NOT TARGET Vulkan::glslc)
message(FATAL_ERROR "Could not find glslc")
endif ()
foreach (source IN LISTS ARGN)
cmake_path(ABSOLUTE_PATH source OUTPUT_VARIABLE source_abs)
cmake_path(GET source STEM basename)
set(depfile "spirv/${basename}.d")
set(output "spirv/${basename}.spv")
set(dirs "$<TARGET_PROPERTY:${TARGET},INCLUDE_DIRECTORIES>")
set(include_flags "$<$<BOOL:${dirs}>:-I$<JOIN:${dirs},;-I>>")
add_custom_command(
OUTPUT "${output}"
COMMAND "${CMAKE_COMMAND}" -E make_directory spirv
COMMAND Vulkan::glslc -MD -MF "${depfile}" -O "${source_abs}"
-o "${output}" --target-env=vulkan1.2 "${include_flags}"
DEPENDS "${source_abs}"
BYPRODUCTS "${depfile}"
COMMENT "Compiling SPIRV: ${source} -> ${output}"
DEPFILE "${depfile}"
VERBATIM
COMMAND_EXPAND_LISTS
)
set(shader_target "${TARGET}_${basename}")
add_custom_target("${shader_target}"
DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/${output}")
add_dependencies("${TARGET}" "${shader_target}")
endforeach ()
endfunction()
add_executable(my_target main.cpp)
target_shader_function(my_target shaders/example.comp)
target_include_directories(
my_target PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/shaderutils")
With a CMake minimum version of 3.20 or greater, CMP0116 will be set, which adjusts depfiles that were generated with relative paths to be relative to the top-level binary directory. You can see this in action in the last two command outputs.
For compatibility with this policy, the command to invoke glslc is careful to use only absolute paths or paths relative to ${CMAKE_CURRENT_BINARY_DIR}.
To increase the reusability of this function, I had it reuse the include paths from the TARGET rather than hard-coding shaderutils.
Also remember to always pass absolute paths to the DEPENDS arguments of add_custom_{command,target} to avoid surprising path resolution behaviors.
Finally, since CMake actually comes with a FindVulkan module that can locate glslc, we use that to get the Vulkan::glslc target. Per the documentation, it can be overridden by setting Vulkan_GLSLC_EXECUTABLE.
Terminal logs for VS2022 on Windows with MSVC:
> cmake -S . -B build
...
> cmake --build build --config Release
Checking Build System
Compiling SPIRV: shaders/example.comp -> spirv/example.spv
Building Custom Rule D:/test/CMakeLists.txt
Building Custom Rule D:/test/CMakeLists.txt
main.cpp
my_target.vcxproj -> D:\test\build\Release\my_target.exe
Building Custom Rule D:/test/CMakeLists.txt
> cmake --build build --config Release -- -noLogo
my_target.vcxproj -> D:\test\build\Release\my_target.exe
> notepad shaderutils\fooutils.glsl
> cmake --build build --config Release -- -noLogo
Compiling SPIRV: shaders/example.comp -> spirv/example.spv
my_target.vcxproj -> D:\test\build\Release\my_target.exe
> cmake --build build --config Release -- -noLogo
my_target.vcxproj -> D:\test\build\Release\my_target.exe
and again with Ninja instead of msbuild:
> cmake -G Ninja -S . -B build -DCMAKE_BUILD_TYPE=Release ^
-DVulkan_ROOT=C:/VulkanSDK/1.2.198.1
...
> powershell "cmake --build build | tee output.txt"
[1/3] Compiling SPIRV: shaders/example.comp -> spirv/example.spv
[2/3] Building CXX object CMakeFiles\my_target.dir\main.cpp.obj
[3/3] Linking CXX executable my_target.exe
> powershell "cmake --build build | tee output.txt"
ninja: no work to do.
> notepad shaderutils\fooutils.glsl
> powershell "cmake --build build | tee output.txt"
[1/1] Compiling SPIRV: shaders/example.comp -> spirv/example.spv
The little powershell + tee trick is just to keep the Ninja command log from overwriting itself. I could use --verbose, but then the full command lines would be printed, rather than the tidy summaries.

Can CMake create soft-link to resource directory? [duplicate]

I want to rename certain executables in CMakeLists.txt but also want symbolic links from the older names to new files for backward compatibility. How can this be accomplished on systems that support symbolic links?
Also what are the alternatives for system that does not support symbolic links?
Another way to do it:
INSTALL(CODE "execute_process( \
COMMAND ${CMAKE_COMMAND} -E create_symlink \
${target} \
${link} \
)"
)
This way the symlinking will be done during make install only.
You can create a custom target and use CMake to create symlinks
ADD_CUSTOM_TARGET(link_target ALL
COMMAND ${CMAKE_COMMAND} -E create_symlink ${target} ${link})
This will only work on systems that support symlinks, see the documentation.
Before CMake v3.14, this did not work on Windows. In v3.13, support for Windows was added.
Another method that is a bit more verbose and only runs on install:
macro(install_symlink filepath sympath)
install(CODE "execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${filepath} ${sympath})")
install(CODE "message(\"-- Created symlink: ${sympath} -> ${filepath}\")")
endmacro(install_symlink)
Use it like this (similar to ln -s):
install_symlink(filepath sympath)
Lets say you need to create a link in binary dir to a target located in source directory.
You can try file CREATE_LINK since version 3.14
${CMAKE_COMMAND} -E create_symlink is accessible at Windows since 3.17
You can use execute_process since early cmake versions:
if(WIN32)
get_filename_component(real_path "${dirname}" REALPATH)
string(REPLACE "/" "\\" target_path "${real_path}")
execute_process(
COMMAND cmd /C mklink /J ${dirname} "${target_path}"
WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
)
else()
execute_process(COMMAND "ln -s ${CMAKE_CURRENT_SOURCE_DIR}/${dirname} ${CMAKE_CURRENT_BINARY_DIR}/${dirname}")
endif()
I've added the check to #ulidtko's approach, so symlink doesn't overridden on every rebuild unconditionally:
install(CODE "if (NOT EXISTS ${link})
execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink \
${target} \
${link})
endif()" )
When I build, I create a symlink to the compile_commands.json. This helps clangd and vscode's intellisense.
Here's a full working example of what worked for me.
add_custom_command is what creates the symlink.
cmake_minimum_required(VERSION "3.1.0")
# project name
project("a-s-i-o")
set(CMAKE_CXX_FLAGS
"${CMAKE_CXX_FLAGS} -std=c++17 -pthread -Wall -Wextra -Werror -pedantic -Wno-unused-parameter -Wno-unused-variable -Wno-unused-function -Wno-unused-private-field"
)
# Create `compile_commands.json` file.
#
# This is required by `clangd` to find the header files. For this to work, this
# file must be in the root of the project. Therefore, we create a symbolic link in the root that
# points to the `compile_commands.json` file created by CMake in the `build` directory.
#
# This specific commands creates the file in the build directory. The command `add_custom_command`
# creates the symbolic link in the root directory.
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
add_executable(x main.cpp)
target_include_directories(x PUBLIC "/usr/local/include/asio-1.20.0/include")
# When target `x` is built, a symlink will be created to
# `build/compile_commands.json`. This is required for clangd to be able to find
# the header files included in the project.
add_custom_command(TARGET x
COMMAND ${CMAKE_COMMAND} -E create_symlink "${CMAKE_CURRENT_BINARY_DIR}/compile_commands.json" "../compile_commands.json"
DEPENDS compile_commands.json
VERBATIM ON
)
# Print success message to the console
add_custom_command(TARGET x POST_BUILD
COMMAND echo "Created symlink pointing to `compile_commands.json`"
DEPENDS compile_commands.json
VERBATIM ON
)
I've struggled with this a few different ways with the above responses in order to install '.so.#' files that refer to other '.so.#.#' files. I've had success by not introducing a link to the file, but by installing the '.so.#.#' file as the '.so.#' file.
I.e. instead of
install(
FILES
.../libmpi.so.12.0
DESTINATION lib
)
install(CODE
"EXECUTE_PROCESS( ${CMAKE_COMMAND} -E create_symlink lib/libmpi.so.12.0 lib/libmpi.so.12)")
Which didn't quite work for me even. I have instead had success by doing this.
install(FILES
.../libmpi.so.12.0
RENAME libmpi.so.12
DESTINATION lib
)
Not 'exactly' the same, but sufficient. Don't defeat the problem, solve the problem.
If what you are looking for is links for your executables and library files based on version numbers you can let CMake take care of that for you by setting the appropriate properties SOVERSION and VERSION on your targets:
The following CMakeLists.txt
cmake_minimum_required(VERSION 3.20)
project(version_links C)
add_library(mylib SHARED lib.c)
set_target_properties(mylib PROPERTIES
PUBLIC_HEADER lib.h
VERSION 3.2.1
SOVERSION 3.2
)
add_executable(exec exec.c)
target_link_libraries(exec PRIVATE mylib)
set_target_properties(exec PROPERTIES
VERSION 3.2.1
)
install(TARGETS mylib exec)
produces the following tree inside CMAKE_INSTALL_PREFIX:
${CMAKE_INSTALL_PREFIX}
├── bin
│   ├── exec -> exec-3.2.1
│   └── exec-3.2.1
├── include
│   └── lib.h
└── lib
├── libmylib.so -> libmylib.so.3.2
├── libmylib.so.3.2 -> libmylib.so.3.2.1
└── libmylib.so.3.2.1
References:
https://cmake.org/cmake/help/latest/command/set_target_properties.html
https://cmake.org/cmake/help/latest/manual/cmake-properties.7.html#target-properties
https://cmake.org/cmake/help/latest/prop_tgt/SOVERSION.html

How to instruct CMake to use the build architecture compiler

When using CMake for cross compiling, one generally specifies a toolchain file via the CMAKE_TOOLCHAIN_FILE option. In GNU terminology, one can specify the host architecture toolset using this file. However, one can generally not expect to be able to execute anything built with this toolchain. So often enough, some build tools need to be compiled for the build architecture.
Consider the following setup. I have two source files genfoo.c and bar.c. During build, genfoo.c needs to be compiled and run. Its output needs to be written to foo.h. Then I can compile bar.c, which #include "foo.h". Since CMake defaults to using the host architecture toolchain, the instructions for bar.c are easy. But how do I tell it to use the build architecture toolchain for compiling genfoo.c? Simply saying add_executable(genfoo genfoo.c) will result in using the wrong compiler.
CMake can only handle one compiler at a time. So - if you don't go the long way to set up the other compiler as a new language - you will end up with two configuration cycles.
I see the following approaches to automate this process:
Taking the example "CMake Cross Compiling - Using executables in the build created during the build?" from the CMake pages as a starting point I'll get:
CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(FooBarTest)
# When crosscompiling import the executable targets
if (CMAKE_CROSSCOMPILING)
set(IMPORT_PATH "IMPORTFILE-NOTFOUND" CACHE FILEPATH "Point it to the export file path from a native build")
file(TO_CMAKE_PATH "${IMPORT_PATH}" IMPORT_PATH_CMAKE)
include(${IMPORT_PATH_CMAKE}/genfooTargets.cmake)
# Then use the target name as COMMAND, CMake >= 2.6 knows how to handle this
add_custom_command(
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/foo.h
COMMAND genfoo
)
add_executable(bar bar.cpp ${CMAKE_CURRENT_BINARY_DIR}/foo.h)
target_include_directories(bar PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
endif()
# Only build the generator if not crosscompiling
if (NOT CMAKE_CROSSCOMPILING)
add_executable(genfoo genfoo.cpp)
export(TARGETS genfoo FILE "${CMAKE_CURRENT_BINARY_DIR}/genfooTargets.cmake")
endif()
Then using a script like:
build.sh
#!/bin/bash
if [ ! -d hostBuild ]; then
cmake -E make_directory hostBuild
cmake -E chdir hostBuild cmake ..
fi
cmake --build hostBuild
if [ ! -d crossBuild ]; then
cmake -E make_directory crossBuild
cmake -E chdir crossBuild cmake .. -DIMPORT_PATH=${PWD}/hostBuild -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake
fi
cmake --build crossBuild
I'll get the desired results by calling ./build.sh.
Splitting the CMakeLists.txt and maybe even replace the export()/include() with something where I know the output path of my build tools e.g. by using CMAKE_RUNTIME_OUTPUT_DIRECTORY would simplify things:
CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(FooBarTest)
# Then use the target name as COMMAND. CMake >= 2.6 knows how to handle this
add_custom_command(
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/foo.h
COMMAND genfoo
)
add_executable(bar bar.cpp ${CMAKE_CURRENT_BINARY_DIR}/foo.h)
target_include_directories(bar PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
buildTools/CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(BuildTools)
add_executable(genfoo genfoo.cpp)
build.sh
#!/bin/bash
if [ ! -d crossBuild ]; then
cmake -E make_directory crossBuild
cmake -E chdir crossBuild cmake .. -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake
fi
if [ ! -d hostBuild ]; then
cmake -E make_directory hostBuild
cmake -E chdir hostBuild cmake ../buildTools -DCMAKE_RUNTIME_OUTPUT_DIRECTORY:PATH=${PWD}/crossBuild
fi
cmake --build hostBuild
cmake --build crossBuild
References
Making a CMake library accessible by other CMake packages automatically
CMake build multiple targets in different build directories
How do I make CMake output into a 'bin' dir?
It is possible to do that completely within CMake.
The trick is to run a separate CMake configuring stage within its own space, silently dismissing every crosscompiling setting and using the host's default toolchain, then import the generated outputs into it's parent, crosscompiling build.
First part:
set(host_tools_list wxrc generate_foo)
if(CMAKE_CROSSCOMPILING)
# Pawn off the creation of the host utilities into its own dedicated space
file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/host_tools)
file(TO_NATIVE_PATH ${CMAKE_COMMAND} native_cmake_command)
file(TO_NATIVE_PATH ${CMAKE_CURRENT_SOURCE_DIR} native_cmake_current_source_dir)
execute_process(
COMMAND "${native_cmake_command}" "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}" "${native_cmake_current_source_dir}"
WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/host_tools
)
add_custom_target(host_tools
COMMAND ${CMAKE_COMMAND} --build . --target host_tools --config $<CONFIG>
WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/host_tools
)
include(${CMAKE_CURRENT_BINARY_DIR}/host_tools/host_tools.cmake)
foreach(tgt IN ITEMS ${host_tools_list})
add_dependencies(host${tgt} host_tools)
endforeach()
else()
# Add an empty target, host tools are built inplace
add_custom_target(host_tools
DEPENDS ${host_tools_list}
)
endif()
... then you add the usual add_executable and whatever ...
At the end:
if(NOT CMAKE_CROSSCOMPILING)
foreach(tgt IN ITEMS ${host_tools_list})
add_executable(host${tgt} ALIAS ${tgt})
endforeach()
export(TARGETS ${host_tools_list} NAMESPACE host FILE host_tools.cmake)
endif()
When it crosscompiles, it pawns off the creation of the host-run tools into its own dedicated space, and imports the targets as "hostwxrc" and "hostgenerate_foo", with a dependency on generating the host_tools themselves .
When it doesn't crosscompile, it builds wxrc and generate_foo as-is, and aliases them to hostwxrc and hostgenerate_foo.
After this, when you use $<TARGET_FILE:wxrc>, you refer to the wxrc built for the target platform, and $<TARGET_FILE:hostwxrc> refers to the wxrc built for the host platform, regardless whether they are the same or not.

CMake setup advice for complicated build process (including externalProject)

I have an application with a mildly complicated build process, and as a bit of a newb to CMake, I was wondering if anyone could provide me with any pointers.
At preset, the application consists of a single executable, built from a source tree provided in the src and include folders.
It requires a few libraries to work, the big ones being Boost and Python. Python is embedded in the application, and Boost requires knowledge of the custom python install at compile time. I also use Qt, but I'm just linking against the system Qt for this.
What I'd like to have at the end is a stage folder, containing the compiled executable, and a lib folder with the required boost and python libraries.
At present, I have a single CMakeLists.txt file, and I am using ExternalProject to build Boost and Python from bzipped tarballs of their source. It gets a little messy where I copy out the compiled libs from the prefixed install directories.
Things are working, but I have a feeling I'm doing things very backwards. I sometimes see multiple CMakeLists in nested subdirectories but don't know how they would relate to my project. Would anyone who has worked on similarly scoped projects be able to weigh in and give me some pointers?
I should add that I hope to include Windows as a platform in the near future, and that things are currently running on Linux.
Note: This is my current CMakeLists.txt, I realise that boost isn't configured and that things aren't fully moved to the stage folder. I have been doing this manually, but I wanted to ask before I dig myself much deeper :)
Thanks!
CmakeList.txt
cmake_minimum_required(VERSION 2.6)
set(CMAKE_BUILD_TYPE Debug)
set(PROJ_NAME "mwave")
project(${PROJ_NAME})
include_directories("include")
include(ExternalProject)
# Add cmake dir to cmake module path so custom find modules will work
set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
#Build Python via External Project
ExternalProject_Add(
Python
PREFIX ${CMAKE_CURRENT_BINARY_DIR}/external/python
URL ${CMAKE_CURRENT_SOURCE_DIR}/extern/Python-3.3.0.tar.bz2
URL_MD5 2dbff60afed2b5f66adf6f77dac9e139
UPDATE_COMMAND ""
CONFIGURE_COMMAND ./configure -q --prefix=${CMAKE_CURRENT_BINARY_DIR}/external/python --enable-shared
BUILD_COMMAND make
BUILD_IN_SOURCE 1
INSTALL_COMMAND make install
)
# Manually copy the compiled python files and dirs to our stage folder
add_custom_command(TARGET Python PRE_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_directory
${CMAKE_CURRENT_BINARY_DIR}/external/python/lib/pkgconfig
${CMAKE_CURRENT_BINARY_DIR}/stage/lib/pkgconfig)
add_custom_command(TARGET Python PRE_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_directory
${CMAKE_CURRENT_BINARY_DIR}/external/python/lib/python3.3
${CMAKE_CURRENT_BINARY_DIR}/stage/lib/python3.3)
add_custom_command(TARGET Python PRE_BUILD
COMMAND ${CMAKE_COMMAND} -E copy
${CMAKE_CURRENT_BINARY_DIR}/external/python/lib/libpython3.so
${CMAKE_CURRENT_BINARY_DIR}/stage/lib/libpython3.so)
add_custom_command(TARGET Python PRE_BUILD
COMMAND ${CMAKE_COMMAND} -E copy
${CMAKE_CURRENT_BINARY_DIR}/external/python/lib/libpython3.3m.so.1.0
${CMAKE_CURRENT_BINARY_DIR}/stage/lib/libpython3.3m.so.1.0)
add_custom_command(TARGET Python PRE_BUILD
COMMAND ${CMAKE_COMMAND} -E create_symlink
libpython3.3m.so.1.0
${CMAKE_CURRENT_BINARY_DIR}/stage/lib/libpython3.3m.so)
#Python
set(PYTHON_INCLUDE_DIRS "${CMAKE_CURRENT_BINARY_DIR}/external/python/include/python3.3m")
set(PYTHON_LIBRARIES "${CMAKE_CURRENT_BINARY_DIR}/external/python/lib/libpython3.3m.so" "pthread" "m" "util" "readline")
#Build boost via External Project
ExternalProject_Add(
Boost
DEPENDS Python
PREFIX ${CMAKE_CURRENT_BINARY_DIR}/external/boost
URL ${CMAKE_CURRENT_SOURCE_DIR}/extern/boost_1_51_0_mwave.tar.bz2
URL_MD5 fe203a243e451b4dd4754c7b283b1db9
UPDATE_COMMAND ./bootstrap.sh --with-libraries=python,system,thread,program_options
CONFIGURE_COMMAND ""
BUILD_COMMAND ./b2
BUILD_IN_SOURCE 1
INSTALL_COMMAND ""
)
#Boost (workaround until external project is working)
set(Boost_INCLUDE_DIRS "/opt/mwave/include")
set(Boost_LIBRARIES "/opt/mwave/lib/libboost_python3.so" "/opt/mwave/lib/libboost_program_options.so")
#OpenImageIO
set(OIIO_PATH "/opt/mwave/oiio/dist/linux64.debug")
find_package(OIIO REQUIRED)
#Qt4
find_package(Qt4 REQUIRED)
set(QT_USE_QTOPENGL TRUE)
include(${QT_USE_FILE})
add_definitions(${QT_DEFINITIONS})
#OpenGL
find_package(OpenGL REQUIRED)
find_package(GLEW REQUIRED)
# Mwave app
set(HEADERS
"include/Application.h"
"include/ImageChannel.h"
"include/CompDag.h"
"include/Dag.h"
"include/Gui/DagView.h"
"include/Gui/DagScene.h"
"include/Gui/MainWindow.h"
"include/Gui/GLViewer.h"
"include/Gui/Nodes/GNodeEdge.h"
"include/Gui/Nodes/GNodeLabel.h"
"include/Gui/Nodes/GNodeCacheStatus.h"
"include/Gui/Nodes/GNode.h"
"include/Gui/Nodes/GRead.h"
"include/Gui/Nodes/GViewer.h"
"include/MwaveException.h"
"include/Nodes/Node.h"
"include/Nodes/Read.h"
"include/Nodes/Viewer.h"
"include/mwave.h"
"include/main.h"
"include/shaders.h"
)
set(QOBJECT_HEADERS
"include/Gui/QCompDag.h"
"include/Gui/QPythonEditor.h"
"include/Gui/ViewerWidget.h"
)
set(SOURCES
"src/Application.cpp"
"src/CompDag.cpp"
"src/main.cpp"
"src/mwave.cpp"
"src/Dag.cpp"
"src/Gui/DagView.cpp"
"src/Gui/DagScene.cpp"
"src/Gui/MainWindow.cpp"
"src/Gui/QPythonEditor.cpp"
"src/Gui/GLViewer.cpp"
"src/Gui/ViewerWidget.cpp"
"src/Gui/Nodes/GNode.cpp"
"src/Gui/Nodes/GNodeEdge.cpp"
"src/Gui/QCompDag.cpp"
"src/Nodes/Node.cpp"
"src/Nodes/Read.cpp"
"src/Nodes/Viewer.cpp"
)
QT4_WRAP_CPP(HEADERS_MOC ${QOBJECT_HEADERS})
## Compiler flags
if(CMAKE_COMPILER_IS_GNUCXX)
set(CMAKE_CXX_FLAGS "-O2") ## Optimize
set(CMAKE_CXX_FLAGS "-O3") ## Optimize More
endif()
include_directories(${PYTHON_INCLUDE_DIRS}
${Boost_INCLUDE_DIRS}
${GLEW_INCLUDE_PATH}
${OPENGL_INCLUDE_DIR}
${OIIO_INCLUDE_DIR}
)
add_executable(mwave WIN32 ${HEADERS} ${HEADERS_MOC} ${SOURCES})
set_target_properties(mwave PROPERTIES OUTPUT_NAME mwave.bin)
target_link_libraries( mwave
${PYTHON_LIBRARIES}
${Boost_LIBRARIES}
${OIIO_LIBRARIES}
${GLEW_LIBRARY}
${OPENGL_LIBRARIES}
${QT_LIBRARIES})
cmake 2.6, which you are using, does not support ExternalProjects.
ExternalProjects are supported in cmake 2.8 series. Please move to cmake 2.8.
The below link clarifies
http://www.cmake.org/pipermail/cmake/2011-June/044993.html