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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
# Vcpkg and Android
Android is not officialy supported, and there are no official android triplets at the moment.
However, some packages can compile to Android, and the situation is improving: see the list of [PR related to Android](https://github.com/Microsoft/vcpkg/pulls?q=+android+).
## Android build requirements
1. Download the [android ndk](https://developer.android.com/ndk/downloads/)
2. Set environment variable `ANDROID_NDK_HOME` to your android ndk installation.
For example:
````bash
export ANDROID_NDK_HOME=/home/your-account/Android/Sdk/ndk-bundle
````
Or:
````bash
export ANDROID_NDK_HOME=/home/your-account/Android/android-ndk-r21b
````
3. Install [vcpkg](https://github.com/microsoft/vcpkg)
4. Set environment variable `VCPKG_ROOT` to your vcpkg installation.
````bash
export VCPKG_ROOT=/path/to/vcpkg
````
## Create the android triplets
### Android ABI and corresponding vcpkg triplets
There are four different Android ABI, each of which maps to
a vcpkg triplet. The following table outlines the mapping from vcpkg architectures to android architectures
|VCPKG_TARGET_TRIPLET | ANDROID_ABI |
|---------------------------|----------------------|
|arm64-android | arm64-v8a |
|arm-android | armeabi-v7a |
|x64-android | x86_64 |
|x86-android | x86 |
### Create the android triplets
You can copy-paste the script below to populate them, and adjust them to your needs if required.
````bash
cd $VCPKG_ROOT
echo "
set(VCPKG_TARGET_ARCHITECTURE arm)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)
set(VCPKG_CMAKE_SYSTEM_NAME Android)
" > triplets/community/arm-android.cmake
echo "
set(VCPKG_TARGET_ARCHITECTURE arm64)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)
set(VCPKG_CMAKE_SYSTEM_NAME Android)
" > triplets/community/arm64-android.cmake
echo "
set(VCPKG_TARGET_ARCHITECTURE x86)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)
set(VCPKG_CMAKE_SYSTEM_NAME Android)
" > triplets/community/x86-android.cmake
echo "
set(VCPKG_TARGET_ARCHITECTURE x64)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)
set(VCPKG_CMAKE_SYSTEM_NAME Android)
" > triplets/community/x64-android.cmake
````
## Install libraries for Android using vcpkg
Example for jsoncpp:
````bash
cd $VCPKG_ROOT
# specify the triplet like this
./vcpkg install jsoncpp --triplet arm-android
# or like this
./vcpkg install jsoncpp:arm64-android
./vcpkg install jsoncpp:x86-android
./vcpkg install jsoncpp:x64-android
````
## Consume libraries using vpckg, cmake and the android toolchain
1. Combine vcpkg and Android toolchains
vcpkg and android both provide dedicated toolchains:
````bash
vcpkg_toolchain_file=$VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake
android_toolchain_file=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmake
````
When using vcpkg, the vcpkg toolchain shall be specified first.
However, vcpkg provides a way to preload and additional toolchain, with the VCPKG_CHAINLOAD_TOOLCHAIN_FILE option.
````bash
cmake \
-DCMAKE_TOOLCHAIN_FILE=$vcpkg_toolchain_file \
-DVCPKG_CHAINLOAD_TOOLCHAIN_FILE=$android_toolchain_file \
...
````
2. Specifiy the android abi and vcpkg triplet
When compiling for android, you need to select a matching "android abi" / "vcpkg triplet" pair.
For example:
````bash
android_abi=armeabi-v7a
vcpkg_target_triplet=arm-android
cmake
...
-DVCPKG_TARGET_TRIPLET=$vcpkg_target_triplet \
-DANDROID_ABI=$android_abi
````
### Test on an example
The folder [docs/examples/vcpkg_android_example_cmake](../examples/vcpkg_android_example_cmake) provides a working example, with an android library that consumes the jsoncpp library:
*Details*
* The [CMakeLists](../examples/vcpkg_android_example_cmake/CMakeLists.txt) simply uses `find_package` and `target_link_library`
* The [compile.sh](../examples/vcpkg_android_example_cmake/compile.sh) script enables you to select any matching pair of "android abi" / "vcpkg triplet" and to test the compilation
* The dummy [my_lib.cpp](../examples/vcpkg_android_example_cmake/my_lib.cpp) file uses the jsoncpp library
*Note*: this example only compiles an Android library, as the compilation of a full fledged Android App is beyond the scope of this document.
### Test on an example, using [vcpkg_android.cmake](../examples/vcpkg_android_example_cmake_script/cmake/vcpkg_android.cmake)
The folder [docs/examples/vcpkg_android_example_cmake_script](../examples/vcpkg_android_example_cmake_script) provides the same example, and uses a cmake script in order to simplify the usage.
*Details*
* The main [CMakeLists](../examples/vcpkg_android_example_cmake_script/CMakeLists.txt) loads [vcpkg_android.cmake](../examples/vcpkg_android_example_cmake_script/cmake/vcpkg_android.cmake) if the flag `VCPKG_TARGET_ANDROID` is set:
````cmake
if (VCPKG_TARGET_ANDROID)
include("cmake/vcpkg_android.cmake")
endif()
````
*Important: place these lines before calling project() !*
* The [compile.sh](../examples/vcpkg_android_example_cmake_script/compile.sh) script shows that it is then possible to compile for android using a simple cmake invocation, for example:
````bash
cmake .. -DVCPKG_TARGET_ANDROID=ON -DANDROID_ABI=armeabi-v7a
````
## Consume libraries using vpckg, and Android prefab Archives (AAR files)
See [prefab.md](../specifications/prefab.md)
|
