vcpkg/docs/maintainers/vcpkg_check_features.md
Victor Romero a3a6530631
[vcpkg_check_features] Set output variable explicitly and allow reverse-logic check (#7558)
* [vcpkg_check_features] Set OUT_EXPAND_OPTIONS explicitly

* [vcpkg_check_features] Allow reverse logic for features

* [vcpkg_check_features] Document new parameters

* [vcpkg_check_features] Remove unnecessary logging

* Do not create variables for each feature only set OUT_FEATURE_OPTIONS

* Improve documentation

* Update ports that use vcpkg_check_features()

* Missing documentation updates

* [pcl] Fix tools feature

* [opencv,opencv4] Fix usage of vcpkg_check_features()

* [opencv4] Fix typo
2019-08-13 20:13:55 -07:00

149 lines
4.0 KiB
Markdown

# vcpkg_check_features
Check if one or more features are a part of a package installation.
## Usage
```cmake
vcpkg_check_features(
OUT_FEATURE_OPTIONS <FEATURE_OPTIONS>
[FEATURES
<cuda> <WITH_CUDA>
[<opencv> <WITH_OPENCV>]
...]
[INVERTED_FEATURES
<cuda> <IGNORE_PACKAGE_CUDA>
[<opencv> <IGNORE_PACKAGE_OPENCV>]
...]
)
```
`vcpkg_check_features()` accepts these parameters:
* `OUT_FEATURE_OPTIONS`:
An output variable, the function will clear the variable passed to `OUT_FEATURE_OPTIONS`
and then set it to contain a list of option definitions (`-D<OPTION_NAME>=ON|OFF`).
This should be set to `FEATURE_OPTIONS` by convention.
* `FEATURES`:
A list of (`FEATURE_NAME`, `OPTION_NAME`) pairs.
For each `FEATURE_NAME` a definition is added to `OUT_FEATURE_OPTIONS` in the form of:
* `-D<OPTION_NAME>=ON`, if a feature is specified for installation,
* `-D<OPTION_NAME>=OFF`, otherwise.
* `INVERTED_FEATURES`:
A list of (`FEATURE_NAME`, `OPTION_NAME`) pairs, uses reversed logic from `FEATURES`.
For each `FEATURE_NAME` a definition is added to `OUT_FEATURE_OPTIONS` in the form of:
* `-D<OPTION_NAME>=OFF`, if a feature is specified for installation,
* `-D<OPTION_NAME>=ON`, otherwise.
## Notes
The `FEATURES` name parameter can be omitted if no `INVERTED_FEATURES` are used.
At least one (`FEATURE_NAME`, `OPTION_NAME`) pair must be passed to the function call.
Arguments passed to `FEATURES` and `INVERTED_FEATURES` are not validated to prevent duplication.
If the same (`FEATURE_NAME`, `OPTION_NAME`) pair is passed to both lists,
two conflicting definitions are added to `OUT_FEATURE_OPTIONS`.
## Examples
### Example 1: Regular features
```cmake
$ ./vcpkg install mimalloc[asm,secure]
# ports/mimalloc/portfile.cmake
vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
# Keyword FEATURES is optional if INVERTED_FEATURES are not used
asm MI_SEE_ASM
override MI_OVERRIDE
secure MI_SECURE
)
vcpkg_configure_cmake(
SOURCE_PATH ${SOURCE_PATH}
PREFER_NINJA
OPTIONS
# Expands to "-DMI_SEE_ASM=ON; -DMI_OVERRIDE=OFF; -DMI_SECURE=ON"
${FEATURE_OPTIONS}
)
```
### Example 2: Inverted features
```cmake
$ ./vcpkg install cpprestsdk[websockets]
# ports/cpprestsdk/portfile.cmake
vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
INVERTED_FEATURES # <- Keyword INVERTED_FEATURES required
brotli CPPREST_EXCLUDE_BROTLI
websockets CPPREST_EXCLUDE_WEBSOCKETS
)
vcpkg_configure_cmake(
SOURCE_PATH ${SOURCE_PATH}
PREFER_NINJA
OPTIONS
# Expands to "-DCPPREST_EXCLUDE_BROTLI=ON; -DCPPREST_EXCLUDE_WEBSOCKETS=OFF"
${FEATURE_OPTIONS}
)
```
### Example 3: Set multiple options for same feature
```cmake
$ ./vcpkg install pcl[cuda]
# ports/pcl/portfile.cmake
vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
cuda WITH_CUDA
cuda BUILD_CUDA
cuda BUILD_GPU
)
vcpkg_configure_cmake(
SOURCE_PATH ${SOURCE_PATH}
PREFER_NINJA
OPTIONS
# Expands to "-DWITH_CUDA=ON; -DBUILD_CUDA=ON; -DBUILD_GPU=ON"
${FEATURE_OPTIONS}
)
```
### Example 4: Use regular and inverted features
```cmake
$ ./vcpkg install rocksdb[tbb]
# ports/rocksdb/portfile.cmake
vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
FEATURES # <- Keyword FEATURES is required because INVERTED_FEATURES are being used
tbb WITH_TBB
INVERTED_FEATURES
tbb ROCKSDB_IGNORE_PACKAGE_TBB
)
vcpkg_configure_cmake(
SOURCE_PATH ${SOURCE_PATH}
PREFER_NINJA
OPTIONS
# Expands to "-DWITH_TBB=ON; -DROCKSDB_IGNORE_PACKAGE_TBB=OFF"
${FEATURE_OPTIONS}
)
```
## Examples in portfiles
* [cpprestsdk](https://github.com/microsoft/vcpkg/blob/master/ports/cpprestsdk/portfile.cmake)
* [pcl](https://github.com/microsoft/vcpkg/blob/master/ports/pcl/portfile.cmake)
* [rocksdb](https://github.com/microsoft/vcpkg/blob/master/ports/rocksdb/portfile.cmake)
## Source
[scripts/cmake/vcpkg_check_features.cmake](https://github.com/Microsoft/vcpkg/blob/master/scripts/cmake/vcpkg_check_features.cmake)