blob: 58da6e33f5fddfdcf6d5503da30dc77fdce4b0c5 [file] [log] [blame]
// 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.docgen;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.devtools.build.docgen.starlark.StarlarkBuiltinDoc;
import com.google.devtools.build.docgen.starlark.StarlarkConstructorMethodDoc;
import com.google.devtools.build.docgen.starlark.StarlarkJavaMethodDoc;
import com.google.devtools.build.lib.syntax.CallUtils;
import com.google.devtools.build.lib.syntax.StarlarkSemantics;
import com.google.devtools.build.lib.syntax.StarlarkValue;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.TreeMap;
import javax.annotation.Nullable;
import net.starlark.java.annot.StarlarkBuiltin;
import net.starlark.java.annot.StarlarkConstructor;
import net.starlark.java.annot.StarlarkDocumentationCategory;
import net.starlark.java.annot.StarlarkGlobalLibrary;
import net.starlark.java.annot.StarlarkMethod;
/** A helper class that collects Starlark module documentation. */
final class StarlarkDocumentationCollector {
@StarlarkBuiltin(
name = "globals",
title = "Globals",
category = StarlarkDocumentationCategory.TOP_LEVEL_TYPE,
doc = "Objects, functions and modules registered in the global environment.")
private static final class TopLevelModule implements StarlarkValue {}
private StarlarkDocumentationCollector() {}
/** Returns the StarlarkBuiltin annotation for the top-level Starlark module. */
public static StarlarkBuiltin getTopLevelModule() {
return TopLevelModule.class.getAnnotation(StarlarkBuiltin.class);
}
/**
* Collects the documentation for all Starlark modules comprised of the given classes and returns
* a map that maps Starlark module name to the module documentation.
*/
public static Map<String, StarlarkBuiltinDoc> collectModules(Iterable<Class<?>> classes) {
Map<String, StarlarkBuiltinDoc> modules = new TreeMap<>();
// The top level module first.
// (This is a special case of {@link StarlarkBuiltinDoc} as it has no object name).
StarlarkBuiltin topLevelModule = getTopLevelModule();
modules.put(
topLevelModule.name(), new StarlarkBuiltinDoc(topLevelModule, TopLevelModule.class));
// Creating module documentation is done in three passes.
// 1. Add all classes/interfaces annotated with @StarlarkBuiltin with documented = true.
for (Class<?> candidateClass : classes) {
if (candidateClass.isAnnotationPresent(StarlarkBuiltin.class)) {
collectStarlarkModule(candidateClass, modules);
}
}
// 2. Add all object methods and global functions.
for (Class<?> candidateClass : classes) {
if (candidateClass.isAnnotationPresent(StarlarkBuiltin.class)) {
collectModuleMethods(candidateClass, modules);
}
if (candidateClass.isAnnotationPresent(StarlarkGlobalLibrary.class)) {
collectGlobalLibraryMethods(candidateClass, modules);
}
}
// 3. Add all constructors.
for (Class<?> candidateClass : classes) {
if (candidateClass.isAnnotationPresent(StarlarkBuiltin.class)
|| candidateClass.isAnnotationPresent(StarlarkGlobalLibrary.class)) {
collectConstructorMethods(candidateClass, modules);
}
}
return modules;
}
/**
* Returns the {@link StarlarkBuiltinDoc} entry representing the collection of top level
* functions. (This is a special case of {@link StarlarkBuiltinDoc} as it has no object name).
*/
private static StarlarkBuiltinDoc getTopLevelModuleDoc(Map<String, StarlarkBuiltinDoc> modules) {
return modules.get(getTopLevelModule().name());
}
/**
* Adds a single {@link StarlarkBuiltinDoc} entry to {@code modules} representing the given {@code
* moduleClass}, if it is a documented module.
*/
private static void collectStarlarkModule(
Class<?> moduleClass, Map<String, StarlarkBuiltinDoc> modules) {
if (moduleClass.equals(TopLevelModule.class)) {
// The top level module doc is a special case and is handled separately.
return;
}
StarlarkBuiltin moduleAnnotation =
Preconditions.checkNotNull(moduleClass.getAnnotation(StarlarkBuiltin.class));
if (moduleAnnotation.documented()) {
StarlarkBuiltinDoc previousModuleDoc = modules.get(moduleAnnotation.name());
if (previousModuleDoc == null) {
modules.put(moduleAnnotation.name(), new StarlarkBuiltinDoc(moduleAnnotation, moduleClass));
} else {
// Handle a strange corner-case: If moduleClass has a subclass which is also
// annotated with {@link StarlarkBuiltin} with the same name, and also has the same
// module-level docstring, then the subclass takes precedence.
// (This is useful if one module is a "common" stable module, and its subclass is
// an experimental module that also supports all stable methods.)
validateCompatibleModules(previousModuleDoc.getClassObject(), moduleClass);
if (previousModuleDoc.getClassObject().isAssignableFrom(moduleClass)) {
// The new module is a subclass of the old module, so use the subclass.
modules.put(
moduleAnnotation.name(), new StarlarkBuiltinDoc(moduleAnnotation, moduleClass));
}
}
}
}
/**
* Validate that it is acceptable that the given module classes with the same module name
* co-exist.
*/
private static void validateCompatibleModules(Class<?> one, Class<?> two) {
StarlarkBuiltin moduleOne = one.getAnnotation(StarlarkBuiltin.class);
StarlarkBuiltin moduleTwo = two.getAnnotation(StarlarkBuiltin.class);
if (one.isAssignableFrom(two) || two.isAssignableFrom(one)) {
if (!moduleOne.doc().equals(moduleTwo.doc())) {
throw new IllegalStateException(
String.format(
"%s and %s are related modules but have mismatching documentation for '%s'",
one, two, moduleOne.name()));
}
} else {
throw new IllegalStateException(
String.format(
"%s and %s are unrelated modules with documentation for '%s'",
one, two, moduleOne.name()));
}
}
private static void collectModuleMethods(
Class<?> moduleClass, Map<String, StarlarkBuiltinDoc> modules) {
StarlarkBuiltin moduleAnnotation =
Preconditions.checkNotNull(moduleClass.getAnnotation(StarlarkBuiltin.class));
if (moduleAnnotation.documented()) {
StarlarkBuiltinDoc moduleDoc =
Preconditions.checkNotNull(modules.get(moduleAnnotation.name()));
if (moduleClass == moduleDoc.getClassObject()) {
ImmutableMap<Method, StarlarkMethod> methods =
CallUtils.collectStarlarkMethodsWithAnnotation(moduleClass);
for (Map.Entry<Method, StarlarkMethod> entry : methods.entrySet()) {
// Only collect methods not annotated with @StarlarkConstructor. Methods with
// @StarlarkConstructor are added later.
if (!entry.getKey().isAnnotationPresent(StarlarkConstructor.class)) {
moduleDoc.addMethod(
new StarlarkJavaMethodDoc(moduleDoc.getName(), entry.getKey(), entry.getValue()));
}
}
}
}
}
@Nullable
private static Method getSelfCallConstructorMethod(Class<?> objectClass) {
Method selfCallMethod = CallUtils.getSelfCallMethod(StarlarkSemantics.DEFAULT, objectClass);
if (selfCallMethod != null && selfCallMethod.isAnnotationPresent(StarlarkConstructor.class)) {
return selfCallMethod;
}
return null;
}
/**
* Adds {@link StarlarkJavaMethodDoc} entries to the top level module, one for
* each @StarlarkMethod method defined in the given @StarlarkGlobalLibrary class {@code
* moduleClass}.
*/
private static void collectGlobalLibraryMethods(
Class<?> moduleClass, Map<String, StarlarkBuiltinDoc> modules) {
Preconditions.checkArgument(moduleClass.isAnnotationPresent(StarlarkGlobalLibrary.class));
StarlarkBuiltinDoc topLevelModuleDoc = getTopLevelModuleDoc(modules);
ImmutableMap<Method, StarlarkMethod> methods =
CallUtils.collectStarlarkMethodsWithAnnotation(moduleClass);
for (Map.Entry<Method, StarlarkMethod> entry : methods.entrySet()) {
// Only add non-constructor global library methods. Constructors are added later.
if (!entry.getKey().isAnnotationPresent(StarlarkConstructor.class)) {
topLevelModuleDoc.addMethod(
new StarlarkJavaMethodDoc("", entry.getKey(), entry.getValue()));
}
}
}
private static void collectConstructor(
Map<String, StarlarkBuiltinDoc> modules, Class<?> moduleClass, Method method) {
StarlarkConstructor constructorAnnotation =
Preconditions.checkNotNull(method.getAnnotation(StarlarkConstructor.class));
StarlarkMethod callable =
Preconditions.checkNotNull(method.getAnnotation(StarlarkMethod.class));
Class<?> objectClass = constructorAnnotation.objectType();
StarlarkBuiltin objectModule = objectClass.getAnnotation(StarlarkBuiltin.class);
if (objectModule == null || !objectModule.documented()) {
// The class of the constructed object type has no documentation, so no place to add
// constructor information.
return;
}
StarlarkBuiltinDoc module = modules.get(objectModule.name());
String fullyQualifiedName;
if (!constructorAnnotation.receiverNameForDoc().isEmpty()) {
fullyQualifiedName = constructorAnnotation.receiverNameForDoc();
} else {
String originatingModuleName = getModuleNameForConstructorPrefix(moduleClass, modules);
fullyQualifiedName = getFullyQualifiedName(originatingModuleName, callable);
}
module.setConstructor(new StarlarkConstructorMethodDoc(fullyQualifiedName, method, callable));
}
/**
* Collect two types of constructor methods:
*
* <p>1. Methods that are annotated with @StarlarkConstructor.
*
* <p>2. Structfield methods that return an object which itself has a method with selfCall = true,
* and is annotated with @StarlarkConstructor. (For example, suppose Foo has a structfield method
* 'bar'. If Foo.bar is itself callable, and is a constructor, then Foo.bar() should be treated
* like a constructor method.)
*/
private static void collectConstructorMethods(
Class<?> moduleClass, Map<String, StarlarkBuiltinDoc> modules) {
Method selfCallConstructor = getSelfCallConstructorMethod(moduleClass);
if (selfCallConstructor != null) {
collectConstructor(modules, moduleClass, selfCallConstructor);
}
ImmutableMap<Method, StarlarkMethod> methods =
CallUtils.collectStarlarkMethodsWithAnnotation(moduleClass);
for (Map.Entry<Method, StarlarkMethod> entry : methods.entrySet()) {
if (entry.getKey().isAnnotationPresent(StarlarkConstructor.class)) {
collectConstructor(modules, moduleClass, entry.getKey());
}
Class<?> returnClass = entry.getKey().getReturnType();
Method returnClassConstructor = getSelfCallConstructorMethod(returnClass);
if (returnClassConstructor != null) {
collectConstructor(modules, moduleClass, returnClassConstructor);
}
}
}
private static String getModuleNameForConstructorPrefix(
Class<?> moduleClass, Map<String, StarlarkBuiltinDoc> modules) {
if (moduleClass.isAnnotationPresent(StarlarkBuiltin.class)) {
String moduleName = moduleClass.getAnnotation(StarlarkBuiltin.class).name();
StarlarkBuiltinDoc moduleDoc = Preconditions.checkNotNull(modules.get(moduleName));
if (moduleClass != moduleDoc.getClassObject()) {
throw new IllegalStateException(
"Could not determine module name for constructor defined in " + moduleClass);
}
return moduleName;
} else if (moduleClass.isAnnotationPresent(StarlarkGlobalLibrary.class)) {
return "";
} else {
throw new IllegalArgumentException(moduleClass + " has no valid annotation");
}
}
private static String getFullyQualifiedName(String objectName, StarlarkMethod callable) {
String objectDotExpressionPrefix = objectName.isEmpty() ? "" : objectName + ".";
String methodName = callable.name();
return objectDotExpressionPrefix + methodName;
}
}