I have a project which uses Makefiles. On a branch, I have CMake based build system. Now some team-members wants the OLD make-files based system intact, when cmake is added. But this is not possible after cmake . command overwrites the old Makefile.
Now I can easily avoid it if I can tell CMake to generate makefiles with some non-standard names e.g. makefile.cmake etc. Is it possible?
I am open to consider other options as well. In any case, old Makefiles must not be touched.
Cmake creates a build system in the working directory. So create any empty directory, and run cmake <path-to-source> from there.
Unfortunately, the name "Makefile" in hard-coded several times, in the sources of CMake. You cannot change it. As Peter has pointed out in the other answer, that change is not necessary, because CMake support out-of-source builds.
Related
Can I configure a CLion project to use a Makefile that is not named literally: Makefile?
I have an older project I'd like to build, but the makefile is called Makfile.osx_sdl2.
I'd like to somehow tell CLion to use that name. Note that, the project also has a Makefile which is somehow used by Makfile.osx_sdl2, so renaming or symlinking won't work.
After an error occurred because of a missing flag or incorrectly set environment variable, is it possible to continue compiling once the mistake has been fixed?
I regularly use CMake and make to compile toolkits that take quite a while to compile and, also regularly, I accidentally set variables incorrectly in the process. Just now for example, I was attempting to include OpenInventor headers which on my machine are located in the directory /Users/user/software/prod/coin/include/Inventor.
I mistakenly passed
-DINVENTOR_INCLUDE_DIR=/Users/user/software/prod/coin/include/Inventor
rather than the correct
-DINVENTOR_INCLUDE_DIR=/Users/user/software/prod/coin/include
This only became an issue after 30 minutes when about 95% of the compilation was completed. Because I knew that reconfiguring using CMake would force a recompilation from scratch, I tried to add -I/Users/user/software/prod/coin/include to CMAKE_CXX_FLAGS in CMakeCache.txt but to no avail–it still recompiled from scratch. Since only a single source file actually includes the headers in question, it would be desirable if I could start compiling from the point where it exited with an error once the relevant path has been corrected. How can I do this and, as an aside, why does it force the compiler to start from scratch?
I'm using CMake version 3.11.1 and clang (Apple LLVM version 9.1.0) on macOS 10.13
CMake does not need to recompile everything just because it regenerates its makefiles. It will still perform normal make avoidance operations. However CMake does track the compiler options used to build each target, so if you make a change in the compiler options for all the targets then they'll all need to be rebuilt.
If this compiler option is only needed for one target, you can add it to just that target an no others, with something like this:
set_property(SOURCE my_source.c APPEND PROPERTY
COMPILE_FLAGS -I/foo/bar)
then it should only rebuild that one source file.
CMake looks for files' "last modified" times to decide which files need recompilation. But if you change the input to CMake itself, then it needs to regenerate the Makefiles and therefore recompile everything. But still, one hack may be possible...
CMake stores information about the include directories and the libraries to be linked in various text files in the build directory. So one hack (not recommended, but works) can be to modify these text files.
In the particular example that you mentioned, the hack would be to search and replace all occurrences of /Users/user/software/prod/coin/include/Inventor with /Users/user/software/prod/coin/include in all the files of the build directory.
(As an aside, if you don't already know, you can use make -j <n> to build using multiple threads which can considerably decrease the build times.)
I'm working on my first project using cmake, and for the most part it's been going well but I've run into one problem I can't figure out.
Let's say I have my CMakeLists.txt file located at ~/project/build. I would like for the output from cmake (not the binaries, but the makefile/configuration files) to be independent of where I run cmake from.
As an example, if my terminal is sitting in the ~/project/build directory, calling cmake ~/project/build creates the makefile and everything else within the ~/project/build directory. This is the behaviour that I'd like. If I call cmake ~/project/build from anywhere else, it creates the makefile and everything else in whatever directory the terminal called the program from.
Is it possible to force cmake to generate its makefile and associated files in the same folder as the CMakeLists.txt file? I've taken a look through the documentation and I've had no problems figuring out how to change binary output directories, but I can't really find any mention of what I'm trying to do.
I realize this is a pretty minor annoyance (it's not that hard to move into my build folder before building the project) but I'm just wondering if it's possible and if there's some reason it wouldn't be advised.
You have to use 2 commands for this
1) cmake -B "Dest path(Any path in which u want to generate the output files)" -H"Source path(root CMakeLists.txt path)"
2) cmake --build "Dest path"
I have a Cmake project where I use static libraries from another project (which uses its own unique build system).
I have a bash script set up which compiles the libraries.
The problem arises when a new user checkouts both project. The new user cannot do cmake until the libaries are properly compiled in the other project, and the cmake command find_libarary cant find them.
I made the bash script part of cmake by using the command add_custom_target. But the issue is that it only execute if you do a "make".
Is there a way I can make CMake execute a command while its generating a build system. Or a better way would be to have it ignore the find command until the actual make?
Thanks
Why not LINK_DIRECTORIES(xxx) to the library folder and don't use find_library at all.
Sure, execute_process() function.
I develop C/C++ using the Eclipse IDE. Eclipse also generates a makefile which I don't want to edit as it will simply be overwritten.
I want to use that makefile for nightly build within Hudson.
How do I pass #defines which are made in the project file of the IDE to the makefile ? (and why doesn't Eclipse already include them in the generated makefile?)
I actually had this figured out once, then accidentally overwrote it :-( But at least I know that it can be done...
If you are running make from the command line, use
make CPPFLAGS=-DFOO
which will add -DFOO to all compilations. See also CFLAGS, CXXFLAGS, LDFLAGS in the make manual.
You could write a small program to include the headers and write a makefile fragment which you include in the main makefile (requires GNU make).
This is a fairly ugly solution that requires a fair amount of hand hackery. More elegant would be to parse the project file and write the makefile fragment.
For GCC use -D define.
OP commented below that he wants to pass the define into make and have it pass it on to GCC.
Make does not allow this. Typically you just add another make rule to add defines. For instance 'make release' vs 'make debug'. As the makefile creator you make the two rules and have the defines right in the make file. Now if Eclipse is not putting the defines into the makefile for you, I would say Eclipse is broken.
If you're using autotools another options is to have 2 directories 'bin/debug' and 'bin/release'.
# Simple bootstrap script.
# Remove previously generated filed and call autoreconf.
# At the end configure 2 separate builds.
echo "Setting up Debug configuration: bin/debug"
../../configure CXXFLAGS="-g3 -O0 -DDEBUG=1"
echo "Setting up Release configuration: bin/release"
cd bin/release/
../../configure CXXFLAGS="-O2"
Setup Eclipse. Open the project's properties (Project->Properties->C/C++ Build->Builder Settings) and set the Build Location->Build Directory to
${workspace_loc:/helloworld/bin/debug}
Replacing 'helloworld' with your project's directory relative to the workspace (or you can supply an absolute path ${/abs/path/debug}). Do the same thing with the Release config, replacing "/debug" with "release" at the end of the path.
This method seems like a waste of disk space, but a valid alternative to achieve completely separate builds.