static BuildConfiguration setupTransitions(
BuildConfiguration targetConfiguration,
BuildConfiguration dataConfiguration,
BuildConfiguration hostConfiguration,
ListMultimap<SplitTransition<?>, BuildConfiguration> splitTransitionsTable) {
Set<BuildConfiguration> allConfigurations = new LinkedHashSet<>();
allConfigurations.add(targetConfiguration);
allConfigurations.add(dataConfiguration);
allConfigurations.add(hostConfiguration);
allConfigurations.addAll(splitTransitionsTable.values());
Table<BuildConfiguration, Transition, ConfigurationHolder> transitionBuilder =
HashBasedTable.create();
for (BuildConfiguration from : allConfigurations) {
for (ConfigurationTransition transition : ConfigurationTransition.values()) {
BuildConfiguration to;
if (transition == ConfigurationTransition.HOST) {
to = hostConfiguration;
} else if (transition == ConfigurationTransition.DATA && from == targetConfiguration) {
to = dataConfiguration;
} else {
to = from;
}
transitionBuilder.put(from, transition, new ConfigurationHolder(to));
}
}
// TODO(bazel-team): This makes LIPO totally not work. Just a band-aid until we get around to
// implementing a way for the C++ rules to contribute this transition to the configuration
// collection.
for (BuildConfiguration config : allConfigurations) {
transitionBuilder.put(config, CppTransition.LIPO_COLLECTOR, new ConfigurationHolder(config));
transitionBuilder.put(
config,
CppTransition.TARGET_CONFIG_FOR_LIPO,
new ConfigurationHolder(config.isHostConfiguration() ? null : config));
}
for (BuildConfiguration config : allConfigurations) {
Transitions outgoingTransitions =
new BazelTransitions(
config,
transitionBuilder.row(config),
// Split transitions must not have their own split transitions because then they
// would be applied twice due to a quirk in DependencyResolver. See the comment in
// DependencyResolver.resolveLateBoundAttributes().
splitTransitionsTable.values().contains(config)
? ImmutableListMultimap.<SplitTransition<?>, BuildConfiguration>of()
: splitTransitionsTable);
// We allow host configurations to be shared between target configurations. In that case, the
// transitions may already be set.
// TODO(bazel-team): Check that the transitions are identical, or even better, change the
// code to set the host configuration transitions before we even create the target
// configuration.
if (config.isHostConfiguration() && config.getTransitions() != null) {
continue;
}
config.setConfigurationTransitions(outgoingTransitions);
}
return targetConfiguration;
}
