Context:
When I want to build a projet, there are usually CMakeCache.txt and CMakeVars.txt files that are created at a first stage, e.g. using cmake-gui > configure.
Questions:
What are the differences between these files and what are they used for?
If I have tweaked a lot of options within cmake-gui, which file should I safely backup in an other location (for copying it back later on in order to not spend much time figuring out which options I had checked...) before removing the build/ directory contents (this directory normally includes these two files) if I want to start from a clean build/ directory (which is sometimes needed) ?
Related
I'm using scons as my build system of c++.
There's a sub directory that contains a static library.
I've tried to set:
NoClean("${PATH_TO_DIR}")
But the files in this directory are still removed by scons -c.
Is there a way to prevent this command from removing all files generated in this directory?
The flag -c works more or less like this:
List all the files that could be built by this call of scons if the flag was not there.
Add to the list relevant files marked to be cleaned with Clean().
Delete from the list the files marked with NoClean() (non-recursively).
Remove all the files that are remaining on the list from the filesystem.
SCons is very focused on files and it doesn't work that well with directories. Usually, it just creates them automatically whenever they are needed and for the rest of the time it pretends they doesn't exist and it is all a flat file-system. It doesn't even delete automatically created directories so your NoClean() is double-ineffective :-) (You would need to call Clean() on the directory for SCons to be able to remove it during cleaning.)
I think your only option is to call NoClean() for every file that you create in this directory. (If you have the list/set of those files lying somewhere, you can just call NoClean() once, passing the list to it.)
scons -c . will only remove the target file under the certain directory. So this is a fallback to resolve my problem.
I have a project and there is a ./tests directory at its root containing several hundred MB of data that is used by the tests of several libraries:
./tests
./src/lib1/dune
./src/lib1/tests/dune
./src/lib1/tests/tests.ml
./src/lib2/dune
./src/lib2/tests/dune
./src/lib2/tests/tests.ml
...
I also defined tests that use the data in ./tests for each library like this:
(rule
(alias runtest)
(action (run ./tests/tests.exe)))
I now have to somehow communicate the location of the test data to each of my tests.exe. What is the most elegant way of doing this using dune?
It seems that dune copies my test data into _build which is unnecessary because the data never changes and it doesn't make sense to waste several hundred MB of space that way. From the documentation it seems that %{project_root} would contain the path to my source files but unfortunately, the variable evaluates to . which is useless for the tests which are run after a cd _build/default/src/libX and thus . does not point to the project root anymore. So is there a dune-way to specify the path to the original source directory without ugly hacks?
Right now, I'm using an environment variable containing the full path before I run dune runtest but is there a more integrated way?
I have not tried it myself but it sounds like the data_only_dirs stanza is what you are looking for: https://dune.readthedocs.io/en/stable/dune-files.html#data-only-dirs-since-1-6
In an iOS c++/Qt application, I need to ship a few files and to keep them in their directory structure.
For the Android version, we bundle a zip which we unzip on the target before creating the QApplication.
On iOS, it seems that CMake is not capable of bundling files in a tree:
https://cmake.org/cmake/help/latest/prop_tgt/RESOURCE.html#prop_tgt:RESOURCE
https://cmake.org/cmake/help/latest/prop_sf/MACOSX_PACKAGE_LOCATION.html
I am not sure if this is a limitation of cmake or if this is a global limitation on iOS.
From the docs about iOS bundles:
It uses a relatively flat structure with few extraneous directories in an effort to save disk space and simplify access to the files.
What would be the preferred approach?
Is there a solution to ship the files from CMake directly?
If not, how can I achieve this so that they are available before the QApplication is created?
The xcode command
Thanks to #Cy-4AH, I added the folder in Xcode and could get the command to do this:
CpResource _PATH_TO_DIRECTORY_ _APP_BUNDLE_DIRECTORY_/_RESOURCE_DIR_NAME_
cd /Users/denis/opt/qfield/ios/QField
export PATH="....."
builtin-copy -exclude .DS_Store -exclude CVS -exclude .svn -exclude .git -exclude .hg -strip-debug-symbols -strip-tool /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/strip -resolve-src-symlinks _PATH_TO_DIRECTORY_ _APP_BUNDLE_DIRECTORY_
But how can I create this from cmake? builtin-copyis an xcode command.
Simple system copy command
From an old (2008) discussion, we could use simple cp commands.
This works up to signing, but then I get an error unsealed contents present in the bundle root.
From this answer, it seems related that I cannot simply add folders in the resource directory. From the docs anatomy of framework bundles: Nonlocalized resources reside at the top level of the Resources directory
(Disclaimer: I'm not a CMake user, and there may be a more CMake-ey way to do this)
If you can set up post-build action, the following terminal script can efficiently sync files into your bundle from another location. I use it in my game engine because it only copies updated or new files upon subsequent builds, and preserves directory structure:
mkdir -p PATHTO/ORIGINFOLDERNAME
mkdir -p PATHTOBUILDFOLDER/PROJECTNAME.app/Contents/Resources/DESTINATIONFOLDERNAME
rsync -avu --delete --exclude=".*" PATHTO/ORIGINFOLDERNAME/ PATHTOBUILDFOLDER/PROJECTNAME.app/Contents/Resources/DESTINATIONFOLDERNAME
The mkdir commands are only to ensure that the folders are generated, if they were deleted.
So apparently the CMake method also works for directories.
target_sources(${QT_IOS_TARGET} PRIVATE ${_resource})
set_source_files_properties(${_resource} PROPERTIES MACOSX_PACKAGE_LOCATION Resources)
It will just be added at the root directory of the bundle and not within the Resources.
If the embedded file is not too big, you might consider :
in your source tree, generating a C++ file embedding that file as a constant array. For example, if your file contains just hello, world with a new line, you could have something like
/// file contents.cc
const char file_contents[] = "hello, world\n";
and at the beginning of your program (perhaps in your main function, before your QApplication) call a C++ function which writes such a file (perhaps in /tmp/).
in your build automation (e.g your Makefile or your qmake things), have something which generates the C++ contents.cc file from the genuine source
This is with a POSIX/Linux point of view, adapt my answer to your iOS.
Having used CMake, I've become used to out-of-source builds, which are encouraged with CMake. How can out-of-source builds be done with Cargo?
Using in-source-builds again feels like a step backwards:
Development tools need to be configured to ignore paths. Sometimes multiple plugins and development tools - especially using VIM or Emacs!
Some tools can't be configured to easily hide build files. While dotfiles are typically hidden, they will still show Cargo.lock and target/, worse still, recursively exposing their contents.
Deleting un-tracked files to remove everything outside of version control, typically to cleanup editor temp files or some test output, can backfire if you forgot to add a new file to version control and don't manually check the file list properly before deleting them.
Dependencies are downloaded into your source code path, sometimes adding *.rs files in the target directory as part of building indirect deps, so operating on all *.rs files may accidentally pickup other files which aren't in a hidden directory, so might not be ignored even after development tools have been configured.
While it's possible to work around all these issues, I'd rather just have an external build path and keep the source directory pristine.
You can specify the directory of the target/ folder either via configuration file (key build.target-dir) or environment variable (CARGO_TARGET_DIR). Here is an example using a configuration file:
Suppose you want to have a directory ~/work/ in which you want to save the Cargo project (~/work/foo/) and next to it the target directory (~/work/my-target/).
$ cd ~/work
$ cargo new --bin foo
$ mkdir .cargo
$ $EDITOR .cargo/config
Then insert the following into the configuration file:
[build]
target-dir = "./my-target"
If you then build in your normal Cargo project directory:
$ cd foo
$ cargo build
You will notice that there is no target/ dir, but everything is in ~/work/my-target/.
However, the Cargo.lock is still saved inside the Cargo project directory, but that kinda makes sense. For executables, you should check the Cargo.lock file into your git! For libraries, you shouldn't. I guess having to ignore one file is better than having to ignore an entire folder.
Lastly, there are a few caveats to changing the target-dir, which are listed in the PR which introduced the feature.
While useful manually setting this up isn't all that convenient, I wanted to be able to build multiple crates within a source tree, having all of them out-of-source, something that ../target-dir configuration option wouldn't achieve.
Helper utility for convenient out-of-source builds
Using the environment variable I've written a small utility to wrap cargo, so it automatically builds out-of-source, supporting crates both at the top-level, on in a subdirectory of the source tree.
Thanks to Lukas for pointing out CARGO_TARGET_DIR and target-dir configuration option.
What I really wanted was a dynamic CARGO_TARGET_DIR that changes relative to where I am.
This bash alias puts all builds in a mirrored directory structure, e.g. instead of putting target into ~/mydir/myproj it puts in into ~/rustbuild/mydir/myproj
alias cargo='CARGO_TARGET_DIR=$(echo $PWD | sed "s|$HOME|$HOME/rustbuild|g") cargo'
You could also make your rustbuild directory hidden.
I would like to edit an existing software to add a new source file (Source.cpp).
But, I can't manage the compilation process (it seems to be automake and it looks very complicated).
The software (iperf 2: https://sourceforge.net/projects/iperf2/files/?source=navbar) is compiled using a classical ./configure make then make install.
If I just add the file to the corresponding source and include directory, I got this error message:
Settings.cpp:(.text+0x969) : undefined reference to ...
It looks like the makefile isn't able to produce the output file associated with my new source file (Source.cpp). So, I probably need to indicate it manually somewhere.
I searched a bit in the project files and it seemed that the file to edit was: "Makefile.am".
I added my source to the variable iperf_SOURCES in that file but it didn't workded.
Could you help me to find the file where I need to indicate my new source file (it seems a pretty standard compilation scheme but I never used automake softwares and this one seems very complicated).
Thank you in advance
This project is built with the autotools, as you already figured out.
The makefiles are built by automake. It takes its input in files that usually have a am file name extension.
The iperf program is built by the makefile generated from src/Makefile.am. This is indicated by:
bin_PROGRAMS = iperf
All (actually this is a simplification, but which holds in this case) source files of a to be built binary are in the corresponding name_SOURCES variable, thus in this case iperf_SOURCES. Just add your source file to the end of that list, like so (keeping their formatting):
iperf_SOURCES = \
Client.cpp \
# lines omitted
tcp_window_size.c \
my_new_file.c
Now, to reflect this change in any future generated src/Makefile you need to run automake. This will modify src/Makefile.in, which is a template that is used by config.sub at the end of configure to generate the actual makefile.
Running automake can happen in various ways:
If you already have makefiles that were generated after an configure these should take care of rebuilding themselves. This seems to fail sometimes though!
You could run automake (in the top level directory) by hand. I've never done this, as there is the better solution to...
Run autoreconf --install (possibly add --force to the arguments) in the top level directory. This will regenerate the entire build system, calling all needed programs such as autoheader, autoconf and of course automake. This is my favorite solution.
The later two options require calling configure again, IMO ideally doing an out of source built:
# in top level dir
mkdir build
cd build
../configure # arguments
make # should now also compile and link your new source file