/**
* Returns the host configuration trimmed to the same fragments as the input configuration. If the
* input is null, returns the top-level host configuration.
*
* <p>For static configurations, this unconditionally returns the (sole) top-level configuration.
*
* <p>This may only be called after {@link #setTopLevelHostConfiguration} has set the correct host
* configuration at the top-level.
*/
public BuildConfiguration getHostConfiguration(BuildConfiguration config) {
if (config == null || !config.useDynamicConfigurations()) {
return topLevelHostConfiguration;
}
// TODO(bazel-team): have the fragment classes be those required by the consuming target's
// transitive closure. This isn't the same as the input configuration's fragment classes -
// the latter may be a proper subset of the former.
//
// ConfigurationFactory.getConfiguration provides the reason why: if a declared required
// fragment is evaluated and returns null, it never gets added to the configuration. So if we
// use the configuration's fragments as the source of truth, that excludes required fragments
// that never made it in.
//
// If we're just trimming an existing configuration, this is no big deal (if the original
// configuration doesn't need the fragment, the trimmed one doesn't either). But this method
// trims a host configuration to the same scope as a target configuration. Since their options
// are different, the host instance may actually be able to produce the fragment. So it's
// wrong and potentially dangerous to unilaterally exclude it.
Set<Class<? extends BuildConfiguration.Fragment>> fragmentClasses = config.fragmentClasses();
BuildConfiguration hostConfig = hostConfigurationCache.get(fragmentClasses);
if (hostConfig != null) {
return hostConfig;
}
BuildConfiguration trimmedConfig =
topLevelHostConfiguration.clone(fragmentClasses, ruleClassProvider);
hostConfigurationCache.put(fragmentClasses, trimmedConfig);
return trimmedConfig;
}
/**
* Returns the host configuration trimmed to the same fragments as the input configuration. If the
* input is null, returns the top-level host configuration.
*
* <p>For static configurations, this unconditionally returns the (sole) top-level configuration.
*
* <p>This may only be called after {@link #setTopLevelHostConfiguration} has set the correct host
* configuration at the top-level.
*/
public BuildConfiguration getHostConfiguration(BuildConfiguration config) {
if (config == null || !config.useDynamicConfigurations()) {
return topLevelHostConfiguration;
}
Set<Class<? extends BuildConfiguration.Fragment>> fragmentClasses = config.fragmentClasses();
BuildConfiguration hostConfig = hostConfigurationCache.get(fragmentClasses);
if (hostConfig != null) {
return hostConfig;
}
BuildConfiguration trimmedConfig =
topLevelHostConfiguration.clone(fragmentClasses, ruleClassProvider);
hostConfigurationCache.put(fragmentClasses, trimmedConfig);
return trimmedConfig;
}
