1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
# 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
```
### 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
|
