I'm using cmake-3.16, and for other technical reason, I must use MODULE to make a shared lib(*.so) in Linux instead of using SHARED.
But with MODULE, cmake does NOT produce target file with name like "libDummy.so.x.x.x", and automatically create a symbolic link with name like "libDummy.so".
So I manually use OUTPUT_NAME_RELEASE to declare the target name as following:
add_library( Dummy MODULE Dummy.cpp )
set_target_properties( Dummy PROPERTIES
PREFIX ""
SUFFIX ""
OUTPUT_NAME_RELEASE "Dummy.so.${PROJECT_VERSION}"
OUTPUT_NAME_DEBUG "Dummy.so.${PROJECT_VERSION}"
)
install( TARGETS Dummy LIBRARY DESTINATION somewhere )
But I don't know how to add a symbolic link for it.
I found the cmake command:
file( CREATE_LINK "Origin.so.0.1.2" "Symlnk.so" RESULT act_res SYMBOLIC )
looks like doing my requirement.
But I don't Known its syntax. I searched in cmake documents, there are very less comments about it.
How to refer the target name of the original Module in the command file( CREATE_LINK ),
and how to make the symbolic link with relative path,
and how to store the symblink into the same folder of the module?
Thx!
Related
we are working on an embedded project in C/C++ and currently some special needs appeared. Background is there are two compiled libraries which define the same symbols. The compiler allows to create relocatable output modules (with partial linking) and to hide symbols for other compilation units when linking. This also means the output module does not need to have all the symbols defined, this will be done in the final linking. Compiler used is TI LTS1.3.0. I will link directly to the relocatable-section of the manual: https://software-dl.ti.com/codegen/docs/tiarmclang/rel1_3_0_LTS/compiler_manual/linker_description/04_linker_options/linker-output-options.html#stdz0756429
The other part of the project is hardly built on CMake with static libraries which are linked against each other via target_link_libraries.
To get this working I created an "add_executable"-target for each of those both output modules with the same symbols. To those I pass the static-libraries by CMake and get the linked with target_link_libraries.
But now I have a problem. All contents of the static libraries are compiled in each of those output modules. This is unwanted behaviour since as said the final linking does the job of linking the missing stuff - so the static-libraries - to it. This should be done with another add_executable command via CMake as well.
using the target include directories property is not suitable since it only adds the include directories of the given target itself but not of the target the target will include and link against.
So e.g. if you have (pseudo code):
#library A
function( create_libA )
add_library( libA src/A.c )
target_include_directories( libA PUBLIC /inc ) #contains A.h
endfunction()
#library B. different location
function( create_libB LIBA )
add_library( libB src/B.c )
target_link_libraries( libB PUBLIC ${LIBA} )
target_include_directories( libB PUBLIC /inc ) #contains B.h
endfunction()
#target output module with partial linking. Only should link and compile LIBTOBELINKEDIN, not libB. different location.
function( build_part_module LIBB LIBTOBELINKEDIN )
add_executable( outputModuleA src/func.c ) #func.c does include A.h
#following would cause libA and libB also to be compiled and linked in the output due to transitive stuff as I understood, which is unwanted.
target_link_libraries( outputModuleA PUBLIC ${LIBB} ${LIBTOBELINKEDIN} )
#trying this
get_target_property(libBInc ${LIBB} INTERFACE_INCLUDE_DIRECTORIES)
#will only include B.h but not A.h. compilation will fail.
target_include_directories(outputModuleA /inc ${libBInc})
I did not find any solution in Cmake itself to solve this problem. It's confusing me since all the include-directories must be known when the libraries are passed transitive, which is stated in the documentation. But I understand that getting the target include directories of just the passed lib does not include the other ones.
Since target_link_libraries does also not work this way I can only think of a maybe recursive solution? But for that my knowledge is just non-existent.
target_link_libraries with something like HEADERS_ONLY would be helpfull for this job.
Also one can say: if the output module contains all the definitions it won't be a problem, since the linker then knows them and will do its magic.
But this is also unwanted, since we use the generated static-libraries to place them into sections in different regions of the RAM directly. This would then mean to create another linker-script for partial linking which defines sections which then can be again moved. But the more we go this direction, the less we need CMake for it.
Instead of get_target_property use $<TARGET_PROPERTY> generator expression: the property's value, extracted by that expression, already includes transitive propagation:
target_include_directories(outputModuleA PRIVATE
$<TARGET_PROPERTY:libB,INTERFACE_INCLUDE_DIRECTORIES>
)
Note, that generator expressions has limited usage: not all functions expects them. Documentation for target_include_directories clearly states that the command supports generator expressions.
How "${PROJECT_BINARY_DIR}/CMakeFiles/project.dir/", the place object files resulted from compilation will be placed on, can be un-hardcoded?
Going straightly to the problem, we have some tests that check objects resulted from compilation on harfbuzz cmake and we use a hardcoded string there but that doesn't seem right and I hope some ${} or $<> exist for that.
I'm afraid you're out of luck here. CMake keeps this as an internal implementation detail, by design.
I'd say it's unlikely to change, but if you want to be absolutely future-proof, you could use a workaround of creating a static library out of the object files and then manually unpacking it back into object files (using the appropriate archiver/librarian) as part of the test. If the object files are also used by another target, and linking to that static library wouldn't work for that target, you can make an object library out of the files and then use that in both the original target and the for-test static library.
Here's an example of how you might achieve this workaround:
add_library(MyObjectLib OBJECT src/a.cpp src/b.cpp)
add_executable(Main src/main.cpp $<TARGET_OBJECTS:MyObjectLib>)
add_library(LibForTesting STATIC $<TARGET_OBJECTS:MyObjectLib>)
add_test(
NAME check-static-inits.sh
COMMAND ${PROJECT_SOURCE_DIR}/src/prepare-and-check-static-inits.sh $<TARGET_FILE:LibForTesting>
)
And here's what the script prepare-and-check-static-inits.sh would look like (pseudo-code):
ar -x $1 -o some_dir
./check-static-inits.sh some_dir
Turning my comment into an answer
There is at the moment no variable or generator expression to get the list of object files used for linking a archive or library target.
But you could append compiler/archiver/linker calls with any program/script and utilize CMake's expansion rules inside those calls.
Note: That will only work CMake's Command-Line Build Tool Generators. And the list(APPEND ...) calls only have to be there once in your CMake code after your project() call.
Examples
Generate a symbolic link to <OBJECT_DIR> with <TARGET_NAME>
project(MyLib)
list(
APPEND CMAKE_CXX_ARCHIVE_FINISH
"\"${CMAKE_COMMAND}\" -E create_symlink \"<OBJECT_DIR>\" \"<TARGET_NAME>\""
)
[...]
add_library(MyLib STATIC src/a.cpp src/b.cpp)
Call some program to do something with the <OBJECTS> list (e.g. echo or write to a file)
project(MyExe)
list(
APPEND CMAKE_CXX_LINK_EXECUTABLE
"\"${CMAKE_COMMAND}\" -E echo \"<OBJECTS>\""
)
[...]
add_executable(MyExe main.cpp)
Directly do something after each object file is generated. In your case where you want to call objdump for each object file it would e.g. be:
list(
APPEND CMAKE_CXX_COMPILE_OBJECT
"${CMAKE_OBJDUMP} -t \"<OBJECT>\" > $(notdir <OBJECT>.dump)"
)
Unfortunately there is no expansion rule for "output file name" hence the platform/make specific trick with $(notdir ...).
References
CMAKE_<LANG>_ARCHIVE_FINISH
CMAKE_<LANG>_LINK_EXECUTABLE
CMAKE_<LANG>_COMPILE_OBJECT
How to get path to object files with CMake for both multiconfiguration generator and makefile based ones?
I have a project that uses some third party libraries. So each time I setup this project with CMake, I have to set each entry (path of the third party library) on the GUI of CMake. I improve this by making CMake script guess the path by this script (learn this technique from OGRE):
# Guess the paths.
set( OGRE_SOURCE "${CMAKE_CURRENT_SOURCE_DIR}/Dependencies/Ogre" CACHE STRING "Path to OGRE source code (see http://www.ogre3d.org/tikiwiki/tiki-index.php?page=CMake+Quick+Start+Guide)" )
So each time I setup with CMake, it will automatic fill the entry OGRE_SOURCE. But that doesn't enough. If the Ogre source is not in the path
"${CMAKE_CURRENT_SOURCE_DIR}/Dependencies/Ogre"
, then I have to open and edit the CMake script or I have to edit the entry on the GUI of CMake. I find that pretty inconvenient, especially when you link to a lot of third party libraries.
So I want to use another technique: preset settings for entries from file - CMake reads the presets from file PresetEntries.txt (that I make) and apply the these presets on the entries (It's a lot quicker to edit the path in text file than on the GUI of CMake).
Here my idea about this preset file: PresetEntries.txt
OGRE_SOURCE=E:/Source/ogre
I found that CMake can read a text file, but if I use this, I have to do string manipulations.
CMake has the file CMakeCache.txt to save the settings on the CMake GUI, but I want it to be simple: it should only has the preset settings that need to be pre-set.
So I wonder if CMake support this preset settings for entries from file.
Edit:
So I read this question and see that CMake can set config from file, but this require to fire cmake with the -C mysettings.cmake, but I wanna it to be automatically with CMake GUI - just edit the file and hit generate button in CMake GUI. So I wanna make this question more specific:
In my CMakeLists.txt should have script like this:
# Guess the paths.
#I wanna have this function from C++
#https://msdn.microsoft.com/en-us/library/windows/desktop/ms724353%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396
GetPrivateProfileString("OGRE", #lpAppName
"OGRE_SOURCE", #lpKeyName
"${CMAKE_CURRENT_SOURCE_DIR}/Dependencies/Ogre", #lpDefault
OGRE_SOURCE_VAR,#lpReturnedString
MAX_PATH, #nSize, may be can reduce this variable
"LibPath.ini") #lpFileName
set( OGRE_SOURCE "${OGRE_SOURCE_VAR}" CACHE STRING "Path to OGRE source code" )
In the file LibPath.ini
[OGRE]
OGRE_SOURCE = "E:/Source/ogre"
So the user can choose to either use the ini file or not.
I don't know if there any way I can use a function that similar to function GetPrivateProfileString (of C++) in CMake.
Thanks for reading
The external libraries should be included by one of the following commands
find_package(ttnlib REQUIRED HINTS /usr/local/lib/cmake)
include_directories(${ttnlib_INCLUDE_DIR})
set(EXTRA_LIBS ${EXTRA_LIBS} ${TTNLIB_LIBRARY})
or
find_library(MY_EXTERNAL_LIB name COOLSTUFF libCOOLSTUFF libCOOLSTUF.so hints /usr/local/lib)
The search for the external packages and libraries should only be necessary for the first run of cmake.
I can't find the function to read the ini file, so what I can do is create a simple function that read simple txt file for myself.
I declare the function in 1 file for other file use it
"\CMake\Dependencies\CommonFunc.cmake"
#------------Define function Read file------------
macro( readSettingFile KEY DEFAULT_RESULT STRING_RESULT_OUT)
unset(STRING_RESULT)
# Read the file
file( READ "${CMAKE_SOURCE_DIR}/LibPath.txt" LIB_PATH_STR )
# Set the variable "Esc" to the ASCII value 27 - basically something
# which is unlikely to conflict with anything in the file contents.
string(ASCII 27 Esc)
# Turn the contents into a list of strings, each ending with an Esc.
# This allows us to preserve blank lines in the file since CMake
# automatically prunes empty list items during a foreach loop.
string(REGEX REPLACE "\n" "${Esc};" LIB_PATH_LINES "${LIB_PATH_STR}")
foreach(LINE ${LIB_PATH_LINES})
if("${LINE}" MATCHES "${KEY}")
#remove the key, leave the content untouch
string(REPLACE "${KEY}" "" STRING_RESULT ${LINE})
# Swap the appended Esc character back out in favour of a line feed
string(REGEX REPLACE "${Esc}" "" STRING_RESULT ${STRING_RESULT})
endif()
endforeach()
if("${STRING_RESULT}" STREQUAL "")
set( STRING_RESULT ${DEFAULT_RESULT} )
endif()
#message( STATIC "---GTA Sa-----" "[${STRING_RESULT}]" )
endmacro()
(I need the help from this answer to write this function :p)
Here is how I use
For example: "\CMake\Dependencies\Ogre.cmake"
#include common functions
include( CMake/Dependencies/CommonFunc.cmake )
#---------------Guess the paths.----------------------
#----Set OGRE_SOURCE
readSettingFile( "OGRE_SOURCE="
"E:/Source/ogre"
STRING_RESULT
)
set( OGRE_SOURCE "${STRING_RESULT}" CACHE STRING "Path to OGRE Source" )
#----Set OGRE_BINARIES
readSettingFile( "OGRE_BINARIES="
"E:/Source/_build/ogre"
STRING_RESULT
)
set( OGRE_BINARIES "${STRING_RESULT}" CACHE STRING "Path to OGRE's build folder generated by CMake" )
Here is the setting file
"\LibPath.txt"
OGRE_SOURCE=E:/Source/ogre
OGRE_BINARIES=E:/Source/_build/ogre
I'm trying to call add_library for all files with certain endings.
The dir structure is:
src
| - CMakeLists.txt (1)
| - main.cpp
| - gui
| - CMakeLists.txt (2)
| - some source and header files
So currently all cc files are in the gui directory.
(1) CMakeLists.txt:
file( GLOB_RECURSE my_sources *.cc )
message(STATUS "my_sources = ${my_sources}")
add_subdirectory( gui )
add_library( my_src ${my_SOURCES} )
target_link_libraries( my_src
my_gui
)
qt5_use_modules( my_src Core Gui Widgets)
(2) CMakeLists.txt:
file( GLOB my_gui_sources *.cc)
add_library( my_gui ${my_gui_sources} )
qt5_use_modules( my_gui Core Gui Widgets)
But I keep getting this output:
You have called ADD_LIBRARY for library my_src without any source files. This typically indicates a problem with your CMakeLists.txt file
-- my_sources = /home/bla/bla/src/gui/BorderLayout.cc;...;/home/bla/bla/my/src/gui/MainWindow.cc
-- my_gui_sources = /home/bla/bla/my/src/gui/BorderLayout.cc;...;/home/bla/bla/my/src/gui/MainWindow.cc
-- Configuring done
-- Generating done
-- Build files have been written to: /home/bla/bla/my/build
I know that I currently don't need the add_library in the first CMakeLists.txt, but later I will. I changed the first GLOB to GLOB_RECURSE, so that it finds at least anything.
For some reason your
file( GLOB my_gui_sources *.cc *.h)
Is not finding any file. To debug, you can print:
message(STATUS "my_gui_sources = ${my_gui_sources}")
Probably you want to use GLOB_RECURSE, which search in sub-directories:
file( GLOB_RECURSE my_gui_sources *.cc *.h)
Note that you don't need to add headers files to the source list.
Take care that you will have to rerun cmake every time you add a file to your project (cmake won't be called automatically, thing that instead happens if you touch one of the cmake files).
Link to documentation of command "file"
Edit:
The actual problem is that in your first CMakeLists.txt file you are using inconsistent naming for your variable (note that casing is important), therefore you have to change your add_library command to:
add_library( my_src ${my_sources} )
Note (off the records :-) ): the fact that casing is important for variable names might be confusing because, on the other hand, in cmake command names are case insensitive. It's also sometimes weird to notice that the character - (minus) might be used as part of the variable name: using _ (underscore) is most of the time preferable.
I am using CMake to build a simple C++ project, hereafter named P. The structure of P is quite simple:
P/src/
P/src/package1
P/src/packege2
P/src/...
P/src/main-app
I would like to collect the libraries in package1, package2, ... in a variable called P_LIBS.
In a first attempt, I tried to collect the libraries available in package1, package2, ... in the variable called P_LIBS initially set in the src/CMakeLists.txt file. However, the updates to P_LIBS made in the CMakeLists.txt of the subfolders are not propagated to the parent folder.
I would rather not write a list of libraries in the main CMakeLists.txt file. I would rather modify such variable while moving in the directory tree.
After a search on the internet I could not find any valid suggestion. If I look at the various Find files, I only see long listings of libraries in their main CMakeLists.txt file.
Is there a way to do what (I hope) I explained above?
Thanks to sakra's link I was able to 'propagate' names up to the parent folder. However, the names I add to the P_LIBS variable are later interpreted as 'library' names, not as reference to CMake targets. In other words, if
P_LIBS = {a, b}
the 'a' and 'b' are interpreted as the library names, i.e. CMake generates:
gcc [...] -l a -o exe
instead of
gcc [...] /path/to/a.o -o exe
(.o or other extensions)
You are propably constructing the targets list as a string, try to make them a list instead. For example:
# in package1/CMakeLists.txt
set(P_LIBS ${P_LIBS} a b PARENT_SCOPE)