s2-mod/deps/zstd/build/cmake/README.md
2025-04-29 02:51:27 -04:00

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# Cmake contributions
Contributions to the cmake build configurations are welcome. Please
use case sensitivity that matches modern (i.e. cmake version 2.6 and above)
conventions of using lower-case for commands, and upper-case for
variables.
## How to build
As cmake doesn't support command like `cmake clean`, it's recommended to perform an "out of source build".
To do this, you can create a new directory and build in it:
```sh
cd build/cmake
mkdir builddir
cd builddir
cmake ..
make
```
Then you can clean all cmake caches by simply delete the new directory:
```sh
rm -rf build/cmake/builddir
```
And of course, you can directly build in build/cmake:
```sh
cd build/cmake
cmake
make
```
To show cmake build options, you can:
```sh
cd build/cmake/builddir
cmake -LH ..
```
Bool options can be set to `ON/OFF` with `-D[option]=[ON/OFF]`. You can configure cmake options like this:
```sh
cd build/cmake/builddir
cmake -DZSTD_BUILD_TESTS=ON -DZSTD_LEGACY_SUPPORT=OFF ..
make
```
**Apple Frameworks**
It's generally recommended to have CMake with versions higher than 3.14 for [iOS-derived platforms](https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html#id27).
```sh
cmake -S. -B build-cmake -DZSTD_FRAMEWORK=ON -DCMAKE_SYSTEM_NAME=iOS
```
Or you can utilize [iOS-CMake](https://github.com/leetal/ios-cmake) toolchain for CMake versions lower than 3.14
```sh
cmake -B build -G Xcode -DCMAKE_TOOLCHAIN_FILE=<Path To ios.toolchain.cmake> -DPLATFORM=OS64 -DZSTD_FRAMEWORK=ON
```
### how to use it with CMake FetchContent
For all options available, you can see it on <https://github.com/facebook/zstd/blob/dev/build/cmake/lib/CMakeLists.txt>
```cmake
include(FetchContent)
set(ZSTD_BUILD_STATIC ON)
set(ZSTD_BUILD_SHARED OFF)
FetchContent_Declare(
zstd
URL "https://github.com/facebook/zstd/releases/download/v1.5.5/zstd-1.5.5.tar.gz"
DOWNLOAD_EXTRACT_TIMESTAMP TRUE
SOURCE_SUBDIR build/cmake
)
FetchContent_MakeAvailable(zstd)
target_link_libraries(
${PROJECT_NAME}
PRIVATE
libzstd_static
)
# On windows and macos this is needed
target_include_directories(
${PROJECT_NAME}
PRIVATE
${zstd_SOURCE_DIR}/lib
)
```
### referring
[Looking for a 'cmake clean' command to clear up CMake output](https://stackoverflow.com/questions/9680420/looking-for-a-cmake-clean-command-to-clear-up-cmake-output)
## CMake Style Recommendations
### Indent all code correctly, i.e. the body of
* if/else/endif
* foreach/endforeach
* while/endwhile
* macro/endmacro
* function/endfunction
Use spaces for indenting, 2, 3 or 4 spaces preferably. Use the same amount of
spaces for indenting as is used in the rest of the file. Do not use tabs.
### Upper/lower casing
Most important: use consistent upper- or lowercasing within one file !
In general, the all-lowercase style is preferred.
So, this is recommended:
```
add_executable(foo foo.c)
```
These forms are discouraged
```
ADD_EXECUTABLE(bar bar.c)
Add_Executable(hello hello.c)
aDd_ExEcUtAbLe(blub blub.c)
```
### End commands
To make the code easier to read, use empty commands for endforeach(), endif(),
endfunction(), endmacro() and endwhile(). Also, use empty else() commands.
For example, do this:
```
if(FOOVAR)
some_command(...)
else()
another_command(...)
endif()
```
and not this:
```
if(BARVAR)
some_other_command(...)
endif(BARVAR)
```
### Other resources for best practices
https://cmake.org/cmake/help/latest/manual/cmake-developer.7.html#modules