In CMakeLists.txt, is there a way to know whether the file was executed from a terminal or via a gui (of some form, e.g. ccmake or cmake-gui)? CMAKE_COMMAND and CMAKE_EDIT_COMMAND are both populated regardless of whether I am running cmake or ccmake.
I was searching through the variables and these two seemed the most promising. I have become enamored with colorizing cmake output, the many wonderful answers there have their drawbacks. Namely, I can either get:
It works as expected in a terminal, but there are escape sequences in ccmake.
It works as expected in a terminal, but the ccmake terminal is overwritten by colorized output (LOL).
Just curious if there is a way to determine this in the CMakeLists.txt. There were variables for script mode (-P) that seemed potentially helpful, but I think I would first need to know which executable (cmake or ccmake) called my CMakeLists.txt in the first place.
As far as I know, there is no way to distinguish whether the code was invoked from CMake or from CMake-gui. The code should behave in the same way, everything else would be a surprise for the user.
You could try to detect whether an instance of CMake-gui is running, but this is error-prone and is not justified for real use cases.
Related
I have run into an issue when writing find scripts. For some reason, automatic appending of suffixes did not work: only library files with .dylib extension were found, however files with .a extension or no extension at all were not.
Practical experimentation lead me to setting CMAKE_FIND_LIBRARY_SUFFIXES to an empty value and restoring the value afterwards. However, this has following effect:
When cmake is run for the first time, generation fails with "CMake Error: Error required internal CMake variable not set, cmake may not be built correctly. Missing variable is CMAKE_FIND_LIBRARY_SUFFIXES".
When I run cmake second time the same way, generation succeeds.
My guess is, things that were found are saved in cache, and the script for finding them is not run the second time.
My question is, how can I work around that issue and ensure that both my framework (that does not have suffixes) is found and cmake does not stop generation?
I am generating on MacOS, for Xcode.
Not sure what is an "official" way for assign a list of a single empty extension, but you may assign a list of two empty extensions:
set(CMAKE_FIND_LIBRARY_SUFFIXES ";")
Unlike to empty value, this assignment would pass possible sanity checks like if(CMAKE_FIND_LIBRARY_SUFFIXES), which probably exists in CMake code as it reports about "Error required internal CMake variable not set".
I'm using add_custom_command() to generate some files. ninja clean removes them, as it should. One of the files is intended as a default/example implementation, to be modified by the user. It is only generated if it does not already exist. I would like for ninja clean not to remove this file.
I have tried a number of things but without success:
add_custom_target(): CMake complains about the missing file unless I name it in BYPRODUCTS, but doing this also leads to removal on clean
set_file_properties(... GENERATED FALSE) doesn't work because CMake complains about the file missing.
set_directory_properties() failed in a similar way: "folder doesn't exist or not yet processed" (it does exist)
I previously generated the example implementation and just let the user copy it or model their code on it. This works, but isn't entirely satisfactory. Is my use-case so unlikely that CMake doesn't support it?
I am afraid you requirment (conceptually, have make create something which make clean does not remove) is rather unusual. I can think of two potential solutions/workarounds.
One, move the file's generation to CMake time. That is, create it using execute_process() instead of add_custom_command(). This may or may not be possible, based on whether the file-generation process (the current custom command) depends on the rest of the build or not.
Two, totally hide the example file's existence from CMake. That is, have the custom command also generate some other file (maybe just a timestamp file) and have its driving custom target depend on that one instead. Do not list the example file as ither the custom command's dependency, output, or byproduct. That way, nothing will depend on it and neither CMake nor Ninja should not care whether it exists or not, so they will not complain or try to clean it up.
If it is an example for the user, it should not be in your build folder, but in the install folder. I don't see why you would need add_custom_command or the other commands you listed.
Therefore, you have to provide install() instructions.
You can then call make install. Cleaning will not remove those and only installing again will overwrite them if necessary.
For those, who come here a long time after the original question was asked (like me), I'll write my solution:
The tool called in add_custom_command generates two files with identical content:
one that is saved in sources, never mentioned anywhere
and one that's marked as byproduct, and then is depended on
So the first one is the file we wanted in the first place.
And the second one is actually used in build process, and gets deleted on clean.
For me the issue is that I actually want to save generated files in VCS so I can track changes. And this approach gives ne what I need.
I want to be able to change the TESTS according to an environment variable like this
make check EXTRA=more
The makefile is generated with Automake. I don't want a configure-time solution via AM_CONDITIONAL. I also don't want to use make check TESTS=more since per default the test shouldn't be in TESTS.
The background is that there are tests that take a long time and shouldn't be run with a normal make check. Adding another target like make extracheck can be done but this doesn't give me the convenient parallel test harness from automake. If there is some variable in automake like TESTS_MORE that automagically works, I would love to hear it.
It should be possible to do it in plain make in a portable way. Someone mentioned here that automake would not touch a Makefile that I include but this is not what I observe. Also the documentation says that included files are interpreted by automake and not make.
If it isn't possible via environment variables, maybe you have a good alternative solution?
I'm trying to get a COTS compiler/linker suite working with CMake and for the most part everything is working well. The issue I am running into is with the librarian.
A typical call as defined in COMPILER-${lang}.cmake file would look like this:
SET(CMAKE_C_CREATE_STATIC_LIBRARY " -v -c ")
but the librarian has no specific way of being told where the object files are so I would like to prepend the object files with the binary directory so as to give the librarian a specific place to find them. However I can't come up with the right syntax to do so.
Any thoughts on how one would do this?
After much work with the compiler/linker suite, it was determined that the main problem was that the compiler did not have the ability of being told where to put the object directly - in essence it did not support the typical -o parameter.
This resulted in the compiler naming the output file whatever it wanted and not paying attention to the that was being passed to it by the make utility.
It also turns out that the main compiler executable was really just a wrapper for the preprocessor, code generator and assembler so I ended up just RE'ing it and building my own wrapper that did support the -o parameter. It was definitively easier doing that trying to get CMake to work with this non-standard approach to generating outputs. Once the compiler started supporting the -o parameter the librarian worked without any issues.
I'm wanting to setup my CMakeLists.txt file so that it can generate the .clang_complete file required by the vim plugin clang_complete.
Ordinarily, you would do this by passing a parameter to the python script it supplies with the compiler and all of the parameters for compilation. Note that I am omitting the actual directory cc_args.py is in to save on space.
cc_args.py gcc test.c -o test -I~/IncludeDirs/
You can also do this during the make phase...
make CC='cc_args.py gcc' CXX='cc_args.py g++'
However, I am unsure of how to (if it is possible to) set this up within a CMakeLists.txt file. It's really annoying to have to type this in every time I want to setup clang_complete. The reason why I want to do it this way, is because I have multiple projects that I use a custom script to build the CMakeLists.txt file, so having to write a script for each one or manually place a generic one is a step I'd like to avoid.
I've tried a couple of things that have so far have come up with errors.
I've tried setting CMAKE_CC_COMPILER and CMAKE_CXX_COMPILER to lines similar to the first i.e. "cc_args.py g++". The errors that come up here say that It can't find the compiler (which is understandable).
The next thing I tried was setting the Compiler variables just to the cc_args.py and adding a flag for the actual compiler: suffice to say, that failed horribly. CMake said that it couldn't compile a test program (considering the script isn't a compiler, and the tests don't use the flags I set, I'm not surprised at this).
So without writing any other external scripts that require moving around, is there anyone that can think of a way that can do this?
The solution is to set the CXX environment variable before executing cmake. Something like that:
CXX="$HOME/.vim/bin/cc_args.py clang++" cmake ..
make
See http://www.guyrutenberg.com/2013/01/29/vim-creating-clang_complete-using-cmake/ for more details.
I know you said "without writing any other external scripts," but it seems like you just need a one-liner:
exec cc_args.py g++
And then set that file as your CMAKE_CXX_COMPILER. You could even use CMake's file() function to write the one-liner at build time if you don't want to have to distribute it.