/**
* Invokes Blaze's constraint enforcement system: checks that this rule's dependencies support its
* environments and reports appropriate errors if violations are found. Also publishes this rule's
* supported environments for the rules that depend on it.
*/
private void checkConstraints() {
if (!ruleContext.getRule().getRuleClassObject().supportsConstraintChecking()) {
return;
}
EnvironmentCollection supportedEnvironments =
ConstraintSemantics.getSupportedEnvironments(ruleContext);
if (supportedEnvironments != null) {
add(SupportedEnvironmentsProvider.class, new SupportedEnvironments(supportedEnvironments));
ConstraintSemantics.checkConstraints(ruleContext, supportedEnvironments);
}
}
/**
* Checks that if this is an environment-restricted build, all top-level targets support the
* expected environments.
*
* @param topLevelTargets the build's top-level targets
* @throws ViewCreationFailedException if constraint enforcement is on, the build declares
* environment-restricted top level configurations, and any top-level target doesn't support
* the expected environments
*/
private void checkTargetEnvironmentRestrictions(
Iterable<ConfiguredTarget> topLevelTargets, PackageManager packageManager)
throws ViewCreationFailedException {
for (ConfiguredTarget topLevelTarget : topLevelTargets) {
BuildConfiguration config = topLevelTarget.getConfiguration();
if (config == null) {
// TODO(bazel-team): support file targets (they should apply package-default constraints).
continue;
} else if (!config.enforceConstraints() || config.getTargetEnvironments().isEmpty()) {
continue;
}
// Parse and collect this configuration's environments.
EnvironmentCollection.Builder builder = new EnvironmentCollection.Builder();
for (Label envLabel : config.getTargetEnvironments()) {
try {
Target env = packageManager.getLoadedTarget(envLabel);
builder.put(ConstraintSemantics.getEnvironmentGroup(env), envLabel);
} catch (NoSuchPackageException
| NoSuchTargetException
| ConstraintSemantics.EnvironmentLookupException e) {
throw new ViewCreationFailedException("invalid target environment", e);
}
}
EnvironmentCollection expectedEnvironments = builder.build();
// Now check the target against those environments.
SupportedEnvironmentsProvider provider =
Verify.verifyNotNull(topLevelTarget.getProvider(SupportedEnvironmentsProvider.class));
Collection<Label> missingEnvironments =
ConstraintSemantics.getUnsupportedEnvironments(
provider.getEnvironments(), expectedEnvironments);
if (!missingEnvironments.isEmpty()) {
throw new ViewCreationFailedException(
String.format(
"This is a restricted-environment build. %s does not support"
+ " required environment%s %s",
topLevelTarget.getLabel(),
missingEnvironments.size() == 1 ? "" : "s",
Joiner.on(", ").join(missingEnvironments)));
}
}
}