I'm trying to create a cmake (3.22) function that creates a target called cppclean for the target that I provide in the arguments
function (cppclean target)
if(${STATIC_CODE_ANALYSIS})
find_program(CPP_CLEAN cppclean)
if(CPP_CLEAN)
add_custom_target(cppclean
COMMAND ${CPP_CLEAN} "--include-path $<JOIN:$<TARGET_PROPERTY:${target},INCLUDE_DIRECTORIES>, --include-path >" $<TARGET_PROPERTY:${target},SOURCE_DIR>
VERBATIM
COMMAND_EXPAND_LISTS
)
else()
message("Cannot find cppclean")
endif()
endif()
endfunction()
However I doesn't work with the error:
No such file or directory: '--include-path ... --include-path ...
--include-path ...'
When I look at the make file that is created I indeed see the quotes around the expanded generator expression which is probably wrong.
If I remove the quotes around the generator expression it gives a different error:
cannot create /home/foo/src: Is a directory
And the make file shows that the JOIN expression is not expanded.
How to fix this?
Related
In the build process, I set directories where I gather the build output of different sub-projects. The directories are set as :
set( CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG "${CMAKE_CURRENT_LIST_DIR}/../build/bin/debug" )
set( CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE "${CMAKE_CURRENT_LIST_DIR}/../build/bin/release" )
Now, I'd like to copy some files (a directory of qt plugins) to that directory dependent on the configuration which it is built for.
I tried:
# copy qt plugins
add_custom_command( TARGET mytarget POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_directory
"${QT_DIR}/../../../plugins"
"${$<UPPER_CASE:CMAKE_RUNTIME_OUTPUT_DIRECTORY_$<CONFIG> >}/plugins"
COMMAND_EXPAND_LISTS)
thus, I try to build a string that equals the variable name and then try to expand that as described here: CMake interpret string as variable. In other words: I would like to have a generator expression that evaluates to the content of CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG or CMAKE_RUNTIME_OUTPUT_DIRECTOR_RELEASE dependent on the current build configuration.
However running cmake with the statement above results in an error:
"CMakeLists.txt:112: error: Syntax error in cmake code at [..] when parsing string ${$<UPPER_CASE:CMAKE_RUNTIME_OUTPUT_DIRECTORY_$<CONFIG> >}/plugins Invalid character ('<') in a variable name: '$'
So my question is, how can I use a generator-expression to access the corresponding variable? (Bonus question: is there another/better way to achieve the same goal?)
So my question is, how can I use a generator-expression to access the corresponding variable?
You cannot. There is currently (CMake <=3.23) no way to expand a variable whose name is determined by the value of a generator expression.
Bonus question: is there another/better way to achieve the same goal?
Yes, and you are almost there! You can use $<TARGET_FILE_DIR:...>:
add_custom_command(
TARGET mytarget POST_BUILD
COMMAND
${CMAKE_COMMAND} -E copy_directory
"${QT_DIR}/../../../plugins"
"$<TARGET_FILE_DIR:mytarget>/plugins"
VERBATIM
)
This works because TARGET_FILE_DIR evaluates to the actual directory containing the executable or library file for mytarget, no matter the active configuration, property values, etc.
Docs: https://cmake.org/cmake/help/latest/manual/cmake-generator-expressions.7.html#genex:TARGET_FILE_DIR
CMAKE_RUNTIME_OUTPUT_DIRECTORY_<CONFIG> is already relative to the binary directory so you should not try to compute the binary directory in its definition. Also, it supports generator expressions. Thus, the following will be much more robust:
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "bin/$<LOWER_CASE:$<CONFIG>>"
CACHE STRING "Common output directory for runtime artifacts")
This has a bunch of concrete benefits:
No need to set CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG or CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE
This will work for MinSizeRel and RelWithDebInfo, plus any custom configurations one might add down the line.
Since it's defined as a cache variable, it can be overridden for debugging / working around name clashes, etc.
A bit more context for (3): most CMAKE_* variables are intended to be either read-only or user-configurable (i.e. at the command line, from the GUI, etc.). Overriding their defaults via set(CACHE) is a polite compromise. A notable exception to this rule is the collection of Qt codegen flags (CMAKE_AUTO{MOC,RCC,UIC}). These must typically be set for the build to produce usable binaries.
For users that are using cmake 3.15 or later and are also using Ninja as a generator, I want to set the new JOB_POOL argument to some large add_custom_command() blocks. For other users, I want to keep my add_custom_command() the same (no JOB_POOL).
In earlier steps, I check the version and the generator and set ${JOB_POOLS} and I also set a variable such that users who should use a pool will see (something like):
For historical reasons, I leave this here, although #Tsyvarev
points out that this is the source of my problem!
The double-quotes are NOT wanted here!
set(USE_POOL "JOB_POOL pool_A")
Users that are not using a pool will not have that variable set.
Now how to leverage that variable in my custom command...?
1.) Generator expressions don't work, just including the text with the previous line...
add_custom_command(
...
$<USE_POOL>
)
2.) I can't seem to simply place the variable in the command, again just including the variable contents on the previous line. For example, when ${JOB_POOL} is set to the string "JOB_POOL pool_A", this code...
For historical reasons, I leave this here, although #Tsyvarev
points out that this is the source of my problem!
Don't use a STRING! No double-quotes!
add_custom_command(
OUTPUT foo
DEPENDS bar
# Comment line here...
${USE_POOL}
COMMAND
${CMAKE_COMMAND} -E ...
)
gives this error...
ninja: error: '../path/to/src/dir/JOB_POOL pool_A', needed by 'path/to/src/dir/foo', missing and no known rule to make it
It simply considers the ${JOB_POOL} string to be another dependency!
3.) I can't use the "APPEND" feature of add_custom_command(). It's just ignored...
if (${USE_POOL})
add_custom_command(
...
APPEND
JOB_POOL pool_A
)
endif()
The only thing that seems to work is to put an "if" around my
entire command, which offends my sensibility since I don't like to duplicate so much code...
if(${USE_POOL})
add_custom_command(
...many lines...
JOB_POOL pool_A
)
else()
add_custom_command(
...many lines...
)
endif()
Do you have a better idea...?
Here's a standalone example for #tsyvarev:
cmake_minimum_required(VERSION 3.15)
project foo
set_property(GLOBAL PROPERTY JOB_POOLS pool_A=2)
# For historical reasons, I leave this here, although #Tsyvarev
# points out that this is the source of my problem!
# Don't use a STRING! No double-quotes!
set(USE_POOL "JOB_POOL pool_A")
add_custom_command(
OUTPUT foo.out
DEPENDS foo.in
${USE_POOL}
COMMAND
${CMAKE_COMMAND} -E copy foo.in foo.out
COMMENT "Converting foo.in -> foo.out"
VERBATIM
)
add_custom_target(foo-out
DEPENDS foo.out
)
% cmake -GNinja .
% ninja foo-out
ninja: error: 'JOB_POOL pool_A', needed by 'foo.out', missing and no known rule to make it
It considers the string to be a dependency... If I move the USE_POOL to after the comment, it considers it part of the comment... If I move it to after the command, it considers it part of the command...
Your JOB_POOL option serves for the user's choice. You may create another variable which contains sequence of related parameters for add_custom_command:
if(JOB_POOL)
set(JOB_POOL_PARAMS JOB_POOL pool_A) # Will add 'JOB_POOL pool_A' sequence of params
else()
set(JOB_POOL_PARAMS) # Will add nothing
endif()
Then use new variable directly in add_custom_command call:
add_custom_command(
...
${JOB_POOL_PARAMS} # Will expand to additional parameters when needed
)
I'm calling my CMakeLists.txt like this:
cmake ../.. -DTARGET=JETSON_NANO
Then, this line:
message(STATUS "------------ TARGET: ${TARGET}")
prints ------------ TARGET: JETSON_NANO
but this line:
if (TARGET STREQUAL JETSON_NANO)
gives error:
if given arguments:
"TARGET" "STREQUAL" "JETSON_NANO"
Why? TARGET is setted!
TARGET is a special keyword for if command. It is used for check whether given target (in CMake sense) exists. Correct usage of this keyword includes two arguments of if:
if(TARGET JETSON_NANO) # Checks whether CMake target JETSON_NANO exists
This is why CMake emits error when you use this keyword with three arguments:
if (TARGET STREQUAL "JETSON_NANO") # Error: 'TARGET' keyword requires two `if` arguments
However, you may swap compared strings in if command:
if ("JETSON_NANO" STREQUAL TARGET) # Compares string "JETSON_NANO" with variable TARGET
See more about if command in its documentation.
I'm currently working on migrating our current build environment from MSBuild to CMake. I have a situation where I need to update the PATH variable in order for the units tests executable to run. This is not a issue for gtest_add_tests, as it uses the source to identify tests. But gtest_discover_tests, which executes the unit tests with the --gtest_list_tests flag, fails to identify any tests because a STATUS_DLL_NOT_FOUND error is encountered during the build.
For example:
add_executable(gTestExe ...)
target_include_directories(gTestExe ...)
target_compile_definitions(gTestExe ...)
target_link_libraries(gTestExe ...)
set (NEWPATH "/path/to/bin;$ENV{PATH}")
STRING(REPLACE ";" "\\;" NEWPATH "${NEWPATH}")
This works:
gtest_add_tests(TARGET gTestExe TEST_LIST allTests)
set_tests_properties(${all_tests} PROPERTIES ENVIRONMENT "PATH=${NEWPATH}")
But this does not:
#set_target_properties(gTestExe PROPERTIES ENVIRONMENT "PATH=${NEWPATH}")
#set_property(DIRECTORY PROPERTY ENVIRONMENT "PATH=${NEWPATH}")
gtest_discover_tests(gTestExe PROPERTIES ENVIRONMENT "PATH=${NEWPATH}")
Edit:
The tests themselves work when added using gtest_add_tests. The issue is the call to discover the tests, during the post build step that gtest_discover_tests registers, fails because the required libraries are not in the PATH.
I came across the same issue this morning and I found a (dirty ?) workaround. The reason why it won't work is a bit complicated, but the workaround is quite simple.
Why it won't work
gtest_discover_tests(gTestExe PROPERTIES ENVIRONMENT "PATH=${NEWPATH}")
Will not work is because the PATH contents are separated by semicolons and therefore are treated by CMake as a list value.
If you look a the GoogleTestAddTests.cmake file (located in C:\Program Files\CMake\share\cmake-3.17\Modules), it treats the PROPERTIES argument with a foreach.
The PROPERTIES value look like this for CMake at this point in the script : ENVIRONMENT;PATH=mypath;mypath2 and will treat mypath2 as a third argument instead of a value for the PATH environment variable.
CMake will then generate the following line :
set_tests_properties( mytest PROPERTIES ENVIRONMENT PATH=mypath mypath2)
Escaping the ; won't work because the list is automatically expended in add_custom_command() in GoogleTest.cmake (l. 420 in cmake 3.17.1) ignoring any form of escaping.
To prevent the cmake foreach to treat each value in the path as a list you can use a bracket argument like :
gtest_discover_tests(gTestExe PROPERTIES ENVIRONMENT "[==[PATH=${NEWPATH}]==]")
The cmake foreach will then treat your argument as one entity. Unfortunately CMake will also put a bracket in the generated code as it contains [ = and maybe spaces :
# This line
if(_arg MATCHES "[^-./:a-zA-Z0-9_]")
set(_args "${_args} [==[${_arg}]==]")
else()
set(_args "${_args} ${_arg}")
endif()
resulting in the following generated script :
set_tests_properties( mytest PROPERTIES ENVIRONMENT [==[ [==[PATH=mypath;mypath2] ]==])
And when executing the test cmake will attempt to read the value only removing the first bracket argument as they don't nest.
Possible workaround
So to do this we need CMake to not use bracket argument on our own bracket argument.
First make a local copy of GoogleTestAddTests.cmake file in your own repository (located in C:\Program Files\CMake\share\cmake-3.17\Modules).
At the beginning of your local copy of GoogleTestAddTests.cmake (l. 12) replace the function add_command by this one :
function(add_command NAME)
set(_args "")
foreach(_arg ${ARGN})
# Patch : allow us to pass a bracket arguments and escape the containing list.
if (_arg MATCHES "^\\[==\\[.*\\]==\\]$")
string(REPLACE ";" "\;" _arg "${_arg}")
set(_args "${_args} ${_arg}")
# end of patch
elseif(_arg MATCHES "[^-./:a-zA-Z0-9_]")
set(_args "${_args} [==[${_arg}]==]")
else()
set(_args "${_args} ${_arg}")
endif()
endforeach()
set(script "${script}${NAME}(${_args})\n" PARENT_SCOPE)
endfunction()
This will make cmake don't use bracket list on our bracket list and automatically escape the ; as set_tests_properties also treat the ; as a list.
Finally we need CMake to use our custom GoogleTestAddTests.cmake instead of the one in CMake.
After your call to include(GoogleTest) set the variable _GOOGLETEST_DISCOVER_TESTS_SCRIPT to the path to your local GoogleTestAddTests.cmake :
# Need google test
include(GoogleTest)
# Use our own version of GoogleTestAddTests.cmake
set(_GOOGLETEST_DISCOVER_TESTS_SCRIPT
${CMAKE_CURRENT_LIST_DIR}/GoogleTestAddTests.cmake
)
Note : In my example the GoogleTestAddTests.cmake is right next to the processing cmake file.
Then a simple call to
gtest_discover_tests(my_target
PROPERTIES ENVIRONMENT "[==[PATH=${my_path};$ENV{PATH}]==]"
)
should work.
Due to the following warning:
CMake Error at test/CMakeLists.txt:29 (get_target_property):
The LOCATION property may not be read from target "my_exe". Use the
target name directly with add_custom_command, or use the generator
expression $<TARGET_FILE>, as appropriate.
which is the result from lines like this:
get_target_property(my_exe_path my_exe LOCATION)
Like recommended in the docs, I tried to use a generator expression like this:
add_executable(my_exe_path main.cpp)
message("path to executable: $<TARGET_FILE:my_exe_path>")
But TARGET_FILE is not being evaluated
path to executable: $<TARGET_FILE:my_exe>
I'm using CMake 3.4 and added cmake_minimum_required(VERSION 3.4) to my CMakeLists.txt so what am I doing wrong?
Here is a quick and easy way to print the value of a generator expression:
add_custom_target(print
${CMAKE_COMMAND} -E echo $<1:hello> $<0:world>
)
In this example, if you run cmake . and then make print, you will see "hello" (without the quotation marks) in the output.
However, if you just use message($<1:hello> $<0:world>), you will see "$<1:hello> $<0:world>" as output (again, without the quotation marks).
While generator expression is stored at configuration stage (when corresponded CMake command is executed),
evaluation of generator expressions is performed at build stage.
This is why message() command prints generator expression in non-dereferenced form: value denoted by the generator expression is not known at this stage.
Moreover, CMake never dereferences generator expressions by itself. Instead, it generates appropriate string in the build file, which is then interpreted by build utility (make, Visual Studio, etc.).
Note, that not every CMake command accepts generator expressions. Each possible usage of generator expressions is explicitely described in documentation for specific command. Moreover, different CMake command flows or different options have different policy about using of generator expressions.
For example, command flow
add_test(NAME <name> COMMAND <executable>)
accepts generator expressions for COMMAND option,
but command flow
add_test(<name> <executable>)
doesn't!
Another example of policies difference:
install(DIRECTORY <dir> DESTINATION <dest>)
In this command flow generator expressions are allowed for DESTINATION, but not for DIRECTORY option.
Again, read documentation carefully.