I have 2 libraries that share same source files:
# src/lib_mt/Makefile.am:
libppb_la_SOURCES = rphs_mt.c timer_mt.c
# src/sipplib/Makefile.am:
libsipp_a_SOURCES = ../lib_mt/rphs_mt.c ../lib_mt/timer_mt.c
Each source file compiled twice. First for lib_mt with -fPIC, second for sipplib without -fPIC.
Object files for each library created in corresponding directory.
Eventually subdir-objects becomes default. How to keep current behavior for these 2 source files? Some explicit rule maybe?
There is no way to disable that the moment it becomes the default. What you can do instead is migrate this to a non-recursive Automake buildsystem. At that point, it will know that there are different targets compiling the same source files with different flags (it requires AC_PROG_CC_C_O to be called in configure.ac.)
Alternatively, the hacky version is to create a src/sipplib/rphs_mt.c file that only contains
#include "../libmt/rphs_mt.c"
so that it is actually a separate build target.
Related
I'm facing the following scenario:
Existing project which uses cmake
External 3rdparty library which only comes with Makefiles
The difference of my situation compared to existing questions is that I don't need to have cmake to build the 3rdparty library via the Makefile. Instead, the 3rdparty library provides a library.mk Makefile which has variables like LIB_SRCS and LIB_INCS containing all source and header files required to compile the library.
My idea is to include the library.mk into the project's CMakeLists.txt and then adding those $(LIB_SRCS) and $(LIB_INCS) to target_sources().
My question: How can I include library.mk into the existing CMakeLists.txt to get access to the $(LIB_SRCS) and $(LIB_INCS) for adding them to target_sources()? I'm looking for something like this:
include("/path/to/library.mk") # Somehow include the library's `library.mk` to expose variables to cmake.
add_executable(my_app)
target_sources(
my_app
PRIVATE
main.c
$(LIB_SRCS) # Add 3rd-party library source files
$(LIB_INCS) # Add 3rd-party library header files
)
Using include() does not work as the library.mk is not a CMake list/file.
Since you can't be sure that your target system will even have Make on it, the only option is to parse the strings out of the .mk file, which might be easy if the variables are set directly as a list of filenames, or really hard if they are set with expansions of other variables, conditionals, etc. Do this with FILE(STRINGS) cmake doc.
Your plan will only work if the Makefiles are trivial, and do not set important compiler flags, define preprocessor variables, modify the include directory, etc. And if they really are trivial, skip the parsing, and just do something like aux_source_directory(<dir> <variable>) to collect all the sources from the library directory.
You might also consider building and maintaining a CMakeLists.txt for this third-party library. Do the conversion once, and store it as a branch off of the "vendor" main branch in your version control system. Whenever you update, update the vendor branch from upstream, and merge or rebase your modifications. Or just store it in your existing project, referring to the source directory of the 3rd-party stuff.
I'm following a tutorial on CMake and I have problems understanding the necessity of using the 'include_directories' command at one point.
Let me explain the project first:
In my working directory I have:
- a main.cpp function, a CMakeLists.txt(the main one), a configuration file, a 'MathFunction' directory and a 'build' directory
In the MathFunction directory I have:
- a CMakeLists.txt file that will be invoked by the main one
- A file 'mysqrt.cxx' that contains the implementation of a function which will be used in 'main.cpp' application
- A 'MathFunctions.h' header file that contains the prototype of that function
In the CMakeLists from 'MathFunction' directory I'm creating a library using code from 'mysqrt.cxx' like this:
add_library(MathFunctions mysqrt.cxx)
This snippet is a part of my main CMake code:
# add the MathFunctions library?
#
if (USE_MYMATH)
include_directories ("${PROJECT_SOURCE_DIR}/MathFunctions") # WHY DO WE NEED THIS
add_subdirectory (MathFunctions)
set (EXTRA_LIBS ${EXTRA_LIBS} MathFunctions)
endif (USE_MYMATH)
add_executable(Tutorial tutorial.cxx)
target_link_libraries (Tutorial MathFunctions)
Now I do not understand why I need too add that 'include_directories' command in order to use the library? Shouldn't it be enough that the last command 'target_link_libraries' links the already created executable and libraries togheter so there would be no need to also include_directories?
Thank you for reading and I'm sorry if I have not explained it very well but I hope you will understand what I mean :D
Command include_directories sets directories for header files (.h) to be searched. Linking (target_link_libraries) with a library basically specifies only a library file (.so, .dll or other type). As you see, these are different things.
When linking executable with a library target, CMake propagates (more precisely, "consumes") some properties of that library target to the executable. Among these properties there is INTERFACE_INCLUDE_DIRECTORIES property, which adds include directories to the executable.
So, when a library target has INTERFACE_INCLUDE_DIRECTORIES property correctly being set, you don't need to explicitly specify include directories for executable:
MathFunctions/CMakeLists.txt:
add_library(MathFunctions mysqrt.cxx)
# Among other things, this call sets INTERFACE_INCLUDE_DIRECTORIES property.
target_include_directories(MathFunctions PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
CMakeLsits.txt:
add_executable(Tutorial tutorial.cxx)
# This also propagates include directories from the library to executable
target_link_libraries (Tutorial MathFunctions)
Note, that using simple
# This *doesn't* set INTERFACE_INCLUDE_DIRECTORIES property.
include_directories(${CMAKE_CURRENT_SOURCE_DIR})
in MathFunctions/CMakeLists.txt doesn't imply propagating include directories to the linked executable.
I have a project where there's only a handful of logical groupings for generating static libraries. However for convenience I want to have the library's source code to be managed with more granular folders.
Currently the only way I know to do this in CMake without having a library for each folder is to just list files as you would normally in with their relative paths:
add_library(SystemAbstraction STATIC "Some/Path/File.cpp")
However I can see this getting unwieldy as the project grows in size with all the different paths.
I tried to see if I could have a CMakeLists.txt in each folder and just use a variable in the base CMakeLists.txt when adding library dependencies. But it seems that add_subdirectory doesn't also import variables?
For expanding the scope of a variable inside a subdirectory, use the PARENT_SCOPE option of set. For example, you can test that if you have
# CMakeLists.txt
set(SRCS main.c)
add_subdirectory(foo)
message(${SRCS})
in the root directory and
# foo/CMakeLists.txt
set(SRCS ${SRCS} foo.c PARENT_SCOPE)
in a subdirectory then it will print main.c foo.c, i.e., the variable is correctly imported into the base CMakeLists.txt.
An option would be to use the object library feature of CMake. You still can but doesn't need to organise your CMake script into subdirectories:
add_library(lib1 OBJECT <srcs>)
add_library(lib2 OBJECT <srcs>)
...
add_library(mainlib $<TARGET_OBJECTS:lib1> $<TARGET_OBJECTS:lib2>)
You can set different compile flags for each object library:
target_include_directories(lib1 PRIVATE incl-dir-for-lib1)
target_compile_definitions(lib2 PRIVATE def-for-lib2)
You still need to set link libraries on your main library:
target_link_libraries(mainlib PRIVATE deps-of-lib1 deps-of-lib2)
Related documentation: Object Libraries
I'm running into a problem with add_custom_command for a custom target (created using add_custom_target).
My general idea is to incorporate a static code analysis tool into the cmake tool-chain. My solution is based on the one described here: https://github.com/rpavlik/cmake-modules/blob/master/CppcheckTargets.cmake
In a nutshell, each project that I want to run static code analysis for has the following two lines of code:
include(cppcheck)
add_cppcheck(${le_project} STYLE POSSIBLE_ERROR FAIL_ON_WARNINGS)
The module has this at the top of the file:
if (NOT TARGET ANALYZE_CODE)
add_custom_target(ANALYZE_CODE WORKING_DIRECTORY ${LE_LITEN_ROOT})
set_target_properties(ANALYZE_CODE PROPERTIES EXCLUDE_FROM_ALL TRUE)
endif ()
and later on in the function the custom command is added:
add_custom_command(TARGET
ANALYZE_CODE
PRE_BUILD
COMMAND
${CPPCHECK_EXECUTABLE}
${CPPCHECK_QUIET_ARG}
${CPPCHECK_TEMPLATE_ARG}
${_cppcheck_args}
${_files}
WORKING_DIRECTORY
"${CMAKE_CURRENT_SOURCE_DIR}"
COMMENT
"${_name}_cppcheck: Running cppcheck on target ${_name}..."
VERBATIM)
The problem I'm seeing is that the command is only added for the project that included the file first. I'm not sure why and what is going on. I verified the following using message() commands:
The target is only created once
The add_custom_command is run for every project that calls the function, with proper arguments
But when I actually look at the target in visual studio, only the first include / function call command is added.
If the file is only included without calling the function, no custom commands are added at all.
Desired behavior:
I would like ONE target named "ANALYZE_CODE" to run all commands added by calls to the function.
I.e. if 3 projects include the two lines from above, the target ANALYZE_CODE is created once but 3 custom commands are added to it, one for each project.
It turns out you're somewhat stuck between a rock and a hard place here. The issue I think boils down to a couple of factors.
Firstly, although the docs don't make it clear, add_custom_command(TARGET ...) only works for targets created in the same directory. So the first subproject to call include(cppcheck) is the only one which can effectively add custom commands to the target ANALYZE_CODE.
A workaround for this might seem to be to move all calls to add_cppcheck from their respective subdirectories up to the top-level CMakeLists file.
include(cppcheck)
add_cppcheck(${le_first_project} STYLE POSSIBLE_ERROR FAIL_ON_WARNINGS)
add_cppcheck(${le_second_project} STYLE POSSIBLE_ERROR FAIL_ON_WARNINGS)
...
This isn't a great solution, since these really belong inside their own subdirs. But a bigger issue is that properties on source files only persist in the scope of the CMakeLists.txt in which they are added. This isn't obvious at all, but from the docs for set_source_files_properties:
Source file properties are visible only to targets added in the same directory (CMakeLists.txt).
The innards of the add_cppcheck have the following block of code:
foreach(_source ${_cppcheck_sources})
get_source_file_property(_cppcheck_lang "${_source}" LANGUAGE)
get_source_file_property(_cppcheck_loc "${_source}" LOCATION)
if("${_cppcheck_lang}" MATCHES "CXX")
list(APPEND _files "${_cppcheck_loc}")
endif()
endforeach()
So this is checking that each source file for the given target is designated as a C++ file before adding it to the list of files to be given to cppcheck. If this function is invoked from within the CMakeLists.txt where the target is defined (i.e. the subdir) then the files all have the appropriate property and are correctly added.
However, if the function is called from the parent CMakeLists.txt, the files have lost their properties, and so none are added and cppcheck is passed an empty list!
Now for the possible fixes. There are probably few ways to get out of this hole - I can point to a couple.
You could continue with the option to always call add_cppcheck from the top-level CMake file and avoid using the source files' properties. So the problem codeblock above could be changed to something more like:
set(CxxExtensions .cpp .CPP .cc .CC .cxx .CXX)
foreach(_source ${_cppcheck_sources})
get_filename_component(Extension "${_source}" EXT)
list(FIND CxxExtensions "${Extension}" IsCxxFile)
if(IsCxxFile GREATER -1)
list(APPEND _files "${_source}")
endif()
endforeach()
You could even enforce that the function is only called from the top-level CMakeLists.txt by adding something like this at the start of the function:
if(NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
message(FATAL_ERROR "This can only be called from the top-level CMakeLists.txt")
endif()
The second fix (which I'd personally favour) is to leave the add_cppcheck calls inside the subdirs and have the function add a custom target rather than command. These targets can successfully be applied as dependencies of the top-level target ANALYZE_CODE. So for example, change the add_custom_command to something like:
add_custom_target(ANALYZE_${_name}
${CPPCHECK_EXECUTABLE}
${CPPCHECK_QUIET_ARG}
${CPPCHECK_TEMPLATE_ARG}
${_cppcheck_args}
${_files}
WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
COMMENT "ANALYZE_${_name}: Running cppcheck on target ${_name}..."
VERBATIM)
add_dependencies(ANALYZE_CODE ANALYZE_${_name})
set_target_properties(ANALYZE_${_name} PROPERTIES FOLDER "Code Analysis")
This should cause building ANALYZE_CODE to trigger building each of the subordinate ANALYZE_... targets.
It has the downside of "polluting" the solution with a lot of extra targets, but an upside is that you could use these targets in the add_test calls (although this may be a step too far):
# CMake 2.8.0 and newer
add_test(NAME ${_name}_cppcheck_test
COMMAND ${CMAKE_COMMAND}
--build ${CMAKE_BINARY_DIR}
--target ANALYZE_${_name})
I have been tooling around with autotools for the past couple of days, and finally have made significant progress. One problem I am having is that I have two libraries that need to be compiled before the main application code. I'm not quite sure how to do this. My directory structure is below and a snippet from my configure.ac as well.
AC_CONFIG_FILES([Makefile
src/Makefile
gtkworkbook/Makefile
csv/Makefile])
AC_OUTPUT
I need the csv/Makefile and gtkworkbook/Makefile to both be compiled before src/Makefile; is there any way to specify this? Right now I am getting an error about the library (csv) not existing during the application compile process.
The order of items in AC_CONFIG_FILES() does not affect the build order. If you're using automake, which I assume you are, it will traverse your directory tree in the order that you list directories in each Makefile.am's SUBDIRS list.
That being said, you should have the order of items in AC_CONFIG_FILES() mirror the build order, for consistency/maintainability.
Example of how your toplevel Makefile.am's SUBDIRS to build in the desired order:
SUBDIRS = csv gtkworkbook src
Also, for this simple case you don't need both AC_CONFIG_FILES() and AC_OUTPUT(). You can pass your list directory to AC_OUTPUT():
AC_OUTPUT([
Makefile
src/Makefile
gtkworkbook/Makefile
csv/Makefile
])