| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| package com.google.devtools.build.lib.rules.python; |
| |
| import static com.google.common.collect.ImmutableSet.toImmutableSet; |
| |
| import com.google.common.base.Ascii; |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.devtools.build.lib.analysis.config.BuildConfigurationValue; |
| import com.google.devtools.build.lib.analysis.config.BuildOptions; |
| import com.google.devtools.build.lib.analysis.config.BuildOptionsView; |
| import com.google.devtools.build.lib.analysis.config.SymlinkDefinition; |
| import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory; |
| import com.google.devtools.build.lib.buildtool.BuildRequestOptions; |
| import com.google.devtools.build.lib.cmdline.RepositoryName; |
| import com.google.devtools.build.lib.events.EventHandler; |
| import com.google.devtools.build.lib.packages.Attribute.AllowedValueSet; |
| import com.google.devtools.build.lib.packages.AttributeMap; |
| import com.google.devtools.build.lib.packages.RawAttributeMapper; |
| import com.google.devtools.build.lib.packages.RuleTransitionData; |
| import com.google.devtools.build.lib.packages.Type; |
| import com.google.devtools.build.lib.util.FileType; |
| import com.google.devtools.build.lib.vfs.Path; |
| import java.util.Set; |
| import java.util.function.Function; |
| |
| /** Rule definitions for Python rules. */ |
| public class PyRuleClasses { |
| |
| public static final FileType PYTHON_SOURCE = FileType.of(".py", ".py3"); |
| |
| /** |
| * A value set of the target and sentinel values that doesn't mention the sentinel in error |
| * messages. |
| */ |
| public static final AllowedValueSet TARGET_PYTHON_ATTR_VALUE_SET = |
| new AllowedValueSet(PythonVersion.TARGET_AND_SENTINEL_STRINGS) { |
| @Override |
| public String getErrorReason(Object value) { |
| return String.format("has to be one of 'PY2' or 'PY3' instead of '%s'", value); |
| } |
| }; |
| |
| /** |
| * Returns a rule transition factory for Python binary rules and other rules that may change the |
| * Python version. |
| * |
| * <p>The factory reads the version specified by the target's {@code python_version} attribute (if |
| * given), which must exist on the rule class. If a value was read successfully, the factory |
| * returns a transition that sets the version to that value. Otherwise, the factory returns {@code |
| * defaultTransition} instead. |
| * |
| * <p>If the attribute has an unparseable value, then the factory returns {@code |
| * defaultTransition} and it is up to the rule's analysis phase ({@link |
| * PyCommon#validatePythonVersionAttr}) to report an attribute error to the user. This case should |
| * be prevented by attribute validation if the rule class is defined correctly. |
| */ |
| public static TransitionFactory<RuleTransitionData> makeVersionTransition( |
| PythonVersionTransition defaultTransition) { |
| return (ruleData) -> { |
| AttributeMap attrs = RawAttributeMapper.of(ruleData.rule()); |
| // Fail fast if we're used on an ill-defined rule class. |
| Preconditions.checkArgument( |
| attrs.has(PyCommon.PYTHON_VERSION_ATTRIBUTE, Type.STRING), |
| "python version transitions require that the RuleClass define a " |
| + "'python_version' attribute"); |
| // Attribute validation should enforce that the attribute string value is either a target |
| // value ("PY2" or "PY3") or the sentinel value ("_INTERNAL_SENTINEL"). But just in case, |
| // we'll, treat an invalid value as the default value rather than propagate an unchecked |
| // exception in this context. That way the user can at least get a clean error message |
| // instead of a crash. |
| PythonVersionTransition transition; |
| try { |
| PythonVersion versionFromAttribute = PyCommon.readPythonVersionFromAttribute(attrs); |
| if (versionFromAttribute == null) { |
| transition = defaultTransition; |
| } else { |
| transition = PythonVersionTransition.toConstant(versionFromAttribute); |
| } |
| } catch (IllegalArgumentException ex) { |
| transition = defaultTransition; |
| } |
| return transition; |
| }; |
| } |
| |
| /** |
| * A Python version transition that sets the version as specified by the target's attributes, with |
| * a default determined by {@link PythonOptions#getDefaultPythonVersion}. |
| */ |
| public static final TransitionFactory<RuleTransitionData> VERSION_TRANSITION = |
| makeVersionTransition(PythonVersionTransition.toDefault()); |
| |
| /** The py2 and py3 symlinks. */ |
| public enum PySymlink implements SymlinkDefinition { |
| PY2(PythonVersion.PY2), |
| PY3(PythonVersion.PY3); |
| |
| private final String versionString; |
| private final PythonVersionTransition transition; |
| |
| PySymlink(PythonVersion version) { |
| this.versionString = Ascii.toLowerCase(version.toString()); |
| this.transition = PythonVersionTransition.toConstant(version); |
| } |
| |
| @Override |
| public String getLinkName(String symlinkPrefix, String productName, String workspaceBaseName) { |
| return symlinkPrefix + versionString; |
| } |
| |
| @Override |
| public ImmutableSet<Path> getLinkPaths( |
| BuildRequestOptions buildRequestOptions, |
| Set<BuildConfigurationValue> targetConfigs, |
| Function<BuildOptions, BuildConfigurationValue> configGetter, |
| RepositoryName repositoryName, |
| Path outputPath, |
| Path execRoot) { |
| if (!buildRequestOptions.experimentalCreatePySymlinks) { |
| return ImmutableSet.of(); |
| } |
| EventHandler e = |
| event -> { |
| throw new UnsupportedOperationException( |
| "This transition shouldn't do anything that could fail.\n" |
| + "TODO(bazel-team): refactor this to not call patch(). Blaze code should" |
| + " not apply transitions unless it absolutely has to, since that requires" |
| + " sequencing (like supporting Starlark flags and handling exceptions)" |
| + " that's easy to get wrong."); |
| }; |
| return targetConfigs.stream() |
| .map( |
| config -> |
| configGetter.apply( |
| transition.patch( |
| new BuildOptionsView( |
| config.getOptions(), transition.requiresOptionFragments()), |
| e))) |
| .map(config -> config.getOutputDirectory(repositoryName).getRoot().asPath()) |
| .distinct() |
| .collect(toImmutableSet()); |
| } |
| } |
| } |