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179 lines
5.4 KiB
179 lines
5.4 KiB
name: feature |
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long_name: Feature option object |
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since: 0.47.0 |
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description: Meson object representing a [`feature` options](Build-options.md#features) |
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methods: |
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- name: enabled |
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returns: bool |
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description: Returns whether the feature was set to `'enabled'` |
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- name: disabled |
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returns: bool |
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description: Returns whether the feature was set to `'disabled'` |
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- name: auto |
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returns: bool |
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description: Returns whether the feature was set to `'auto'` |
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- name: allowed |
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since: 0.59.0 |
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returns: bool |
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description: Returns whether the feature was set to `'enabled'` or `'auto'` |
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- name: disable_auto_if |
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since: 0.59.0 |
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returns: feature |
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description: | |
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Returns the feature, with `'auto'` converted to `'disabled'` if value is true. |
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| Feature | `value = true` | `value = false` | |
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| -------- | -------------- | --------------- | |
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| Auto | Disabled | Auto | |
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| Enabled | Enabled | Enabled | |
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| Disabled | Disabled | Disabled | |
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example: | |
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`disable_auto_if` is useful to give precedence to mutually exclusive dependencies |
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(that provide the same API) if either or both are available: |
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``` |
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# '-Dfoo=auto -Dbar=enabled' will not pick foo even if installed. |
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use_bar = get_option('bar') |
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use_foo = get_option('foo').disable_auto_if(use_bar.enabled()) |
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dep_foo = dependency('foo', required: use_foo) |
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if not dep_foo.found() |
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dep_foo = dependency('bar', required: use_bar) |
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endif |
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``` |
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posargs: |
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value: |
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type: bool |
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description: See the table above |
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- name: enable_auto_if |
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since: 1.1.0 |
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returns: feature |
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description: | |
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Returns the feature, with `'auto'` converted to `'enabled'` if value is true. |
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| Feature | `value = true` | `value = false` | |
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| -------- | -------------- | --------------- | |
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| Auto | Enabled | Auto | |
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| Enabled | Enabled | Enabled | |
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| Disabled | Disabled | Disabled | |
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posargs: |
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value: |
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type: bool |
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description: See the table above |
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- name: require |
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returns: feature |
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since: 0.59.0 |
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description: | |
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Returns the object itself if the value is true; an error if the object is |
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`'enabled'` and the value is false; a disabled feature if the object |
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is `'auto'` or `'disabled'` and the value is false. |
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| Feature | `value = true` | `value = false` | |
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| -------- | -------------- | --------------- | |
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| Auto | Auto | Disabled | |
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| Enabled | Enabled | Error | |
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| Disabled | Disabled | Disabled | |
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example: | |
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`require` is useful to restrict the applicability of `'auto'` features, |
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for example based on other features or on properties of the host machine: |
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``` |
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if get_option('directx').require(host_machine.system() == 'windows', |
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error_message: 'DirectX only available on Windows').allowed() |
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src += ['directx.c'] |
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config.set10('HAVE_DIRECTX', true) |
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endif |
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``` |
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posargs: |
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value: |
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type: bool |
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description: The value to check |
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kwargs: |
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error_message: |
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type: str |
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default: "''" |
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description: The error message to print if the check fails |
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- name: enable_if |
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returns: feature |
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since: 1.1.0 |
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description: | |
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Returns the object itself if the value is false; an error if the object is |
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`'disabled'` and the value is true; an enabled feature if the object |
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is `'auto'` or `'enabled'` and the value is true. |
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| Feature | `value = true` | `value = false` | |
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| -------- | -------------- | --------------- | |
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| Auto | Enabled | Auto | |
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| Enabled | Enabled | Enabled | |
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| Disabled | Error | Disabled | |
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example: | |
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`enable_if` is useful to restrict the applicability of `'auto'` features, |
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particularly when passing them to [[dependency]]: |
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``` |
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use_llvm = get_option('llvm').enable_if(with_clang).enable_if(with_llvm_libs) |
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dep_llvm = dependency('llvm', required: use_llvm) |
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``` |
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posargs: |
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value: |
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type: bool |
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description: The value to check |
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kwargs: |
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error_message: |
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type: str |
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default: "''" |
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description: The error message to print if the check fails |
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- name: disable_if |
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returns: feature |
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since: 1.1.0 |
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description: | |
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Returns the object itself if the value is false; an error if the object is |
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`'enabled'` and the value is true; a disabled feature if the object |
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is `'auto'` or `'disabled'` and the value is true. |
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| Feature | `value = true` | `value = false` | |
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| -------- | -------------- | --------------- | |
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| Auto | Disabled | Auto | |
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| Enabled | Error | Enabled | |
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| Disabled | Disabled | Disabled | |
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This is equivalent to `feature_opt.require(not condition)`, but may make |
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code easier to reason about, especially when mixed with `enable_if` |
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example: | |
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`disable_if` is useful to restrict the applicability of `'auto'` features, |
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particularly when passing them to [[dependency]]: |
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``` |
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use_os_feature = get_option('foo') \ |
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.disable_if(host_machine.system() == 'darwin', error_message : 'os feature not supported on MacOS') |
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dep_os_feature = dependency('os_feature', required: use_os_feature) |
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``` |
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posargs: |
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value: |
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type: bool |
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description: The value to check |
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kwargs: |
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error_message: |
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type: str |
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default: "''" |
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description: The error message to print if the check fails
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