aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/main/java/com/google/devtools/build/docgen/BuildDocCollector.java
blob: 31133cc605298bef76c3b82249cb412441abb4b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
// 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 static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Splitter;
import com.google.common.collect.LinkedListMultimap;
import com.google.common.collect.ListMultimap;
import com.google.devtools.build.docgen.DocgenConsts.RuleType;
import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
import com.google.devtools.build.lib.analysis.RuleDefinition;
import com.google.devtools.build.lib.packages.Attribute;
import com.google.devtools.build.lib.packages.RuleClass;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

/**
 * Class that parses the documentation fragments of rule-classes and
 * generates the html format documentation.
 */
@VisibleForTesting
public class BuildDocCollector {
  private static final Splitter SHARP_SPLITTER = Splitter.on('#').limit(2).trimResults();

  private ConfiguredRuleClassProvider ruleClassProvider;
  private boolean printMessages;

  public BuildDocCollector(ConfiguredRuleClassProvider ruleClassProvider, boolean printMessages) {
    this.ruleClassProvider = ruleClassProvider;
    this.printMessages = printMessages;
  }

  /**
   * Parse the file containing blacklisted rules for documentation. The list is simply a list of
   * rules separated by new lines. Line comments can be added to the file by starting them with #.
   *
   * @param blackList The name of the file containing the blacklist.
   * @return The set of blacklisted rules.
   * @throws IOException
   */
  @VisibleForTesting
  public static Set<String> readBlackList(String blackList) throws IOException {
    Set<String> result = new HashSet<String>();
    if (blackList != null && !blackList.isEmpty()) {
      File file = new File(blackList);
      try (BufferedReader reader = Files.newBufferedReader(file.toPath(), UTF_8)) {
        for (String line = reader.readLine(); line != null; line = reader.readLine()) {
          String rule = SHARP_SPLITTER.split(line).iterator().next();
          if (!rule.isEmpty()) {
            result.add(rule);
          }
        }
      }
    }
    return result;
  }

  /**
   * Creates a map of rule names (keys) to rule documentation (values).
   *
   * <p>This method crawls the specified input directories for rule class definitions (as Java
   * source files) which contain the rules' and attributes' definitions as comments in a
   * specific format. The keys in the returned Map correspond to these rule classes.
   *
   * <p>In the Map's values, all references pointing to other rules, rule attributes, and general
   * documentation (e.g. common definitions, make variables, etc.) are expanded into hyperlinks.
   * The links generated follow either the multi-page or single-page Build Encyclopedia model
   * depending on the mode set for the provided {@link RuleLinkExpander}.
   *
   * @param inputDirs list of directories to scan for documentation
   * @param blackList specify an optional blacklist file that list some rules that should
   *                  not be listed in the output.
   * @param expander The RuleLinkExpander, which is used for expanding links in the rule doc.
   * @throws BuildEncyclopediaDocException
   * @throws IOException
   * @return Map of rule class to rule documentation.
   */
  public Map<String, RuleDocumentation> collect(
      List<String> inputDirs, String blackList, RuleLinkExpander expander)
      throws BuildEncyclopediaDocException, IOException {
    // Read the blackList file
    Set<String> blacklistedRules = readBlackList(blackList);
    // RuleDocumentations are generated in order (based on rule type then alphabetically).
    // The ordering is also used to determine in which rule doc the common attribute docs are
    // generated (they are generated at the first appearance).
    Map<String, RuleDocumentation> ruleDocEntries = new TreeMap<>();
    // RuleDocumentationAttribute objects equal based on attributeName so they have to be
    // collected in a List instead of a Set.
    ListMultimap<String, RuleDocumentationAttribute> attributeDocEntries =
        LinkedListMultimap.create();

    // Map of rule class name to file that defined it.
    Map<String, File> ruleClassFiles = new HashMap<>();

    // Set of files already processed. The same file may be encountered multiple times because
    // directories are processed recursively, and an input directory may be a subdirectory of
    // another one.
    Set<File> processedFiles = new HashSet<>();

    for (String inputDir : inputDirs) {
      if (printMessages) {
        System.out.println(" Processing input directory: " + inputDir);
      }
      int ruleNum = ruleDocEntries.size();
      collectDocs(processedFiles, ruleClassFiles, ruleDocEntries, blacklistedRules,
          attributeDocEntries, new File(inputDir));
      if (printMessages) {
        System.out.println(" " + (ruleDocEntries.size() - ruleNum)
            + " rule documentations found.");
      }
    }

    processAttributeDocs(ruleDocEntries.values(), attributeDocEntries);
    expander.addIndex(buildRuleIndex(ruleDocEntries.values()));
    for (RuleDocumentation rule : ruleDocEntries.values()) {
      rule.setRuleLinkExpander(expander);
    }
    return ruleDocEntries;
  }

  /**
   * Creates a map of rule names (keys) to rule documentation (values).
   *
   * <p>This method crawls the specified input directories for rule class definitions (as Java
   * source files) which contain the rules' and attributes' definitions as comments in a
   * specific format. The keys in the returned Map correspond to these rule classes.
   *
   * <p>In the Map's values, all references pointing to other rules, rule attributes, and general
   * documentation (e.g. common definitions, make variables, etc.) are expanded into hyperlinks.
   * The links generated follow the multi-page Build Encyclopedia model (one page per rule clas.).
   *
   * @param inputDirs list of directories to scan for documentation
   * @param blackList specify an optional blacklist file that list some rules that should
   *                  not be listed in the output.
   * @throws BuildEncyclopediaDocException
   * @throws IOException
   * @return Map of rule class to rule documentation.
   */
  public Map<String, RuleDocumentation> collect(List<String> inputDirs, String blackList)
      throws BuildEncyclopediaDocException, IOException {
    RuleLinkExpander expander = new RuleLinkExpander(
        ruleClassProvider.getProductName(), /* singlePage */ false);
    return collect(inputDirs, blackList, expander);
  }

  /**
   * Generates an index mapping rule name to its normalized rule family name.
   */
  private Map<String, String> buildRuleIndex(Iterable<RuleDocumentation> rules) {
    Map<String, String> index = new HashMap<>();
    for (RuleDocumentation rule : rules) {
      index.put(rule.getRuleName(), RuleFamily.normalize(rule.getRuleFamily()));
    }
    return index;
  }

  /**
   * Go through all attributes of all documented rules and search the best attribute documentation
   * if exists. The best documentation is the closest documentation in the ancestor graph. E.g. if
   * java_library.deps documented in $rule and $java_rule then the one in $java_rule is going to
   * apply since it's a closer ancestor of java_library.
   */
  private void processAttributeDocs(Iterable<RuleDocumentation> ruleDocEntries,
      ListMultimap<String, RuleDocumentationAttribute> attributeDocEntries)
          throws BuildEncyclopediaDocException {
    for (RuleDocumentation ruleDoc : ruleDocEntries) {
      RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(ruleDoc.getRuleName());
      if (ruleClass != null) {
        if (ruleClass.isDocumented()) {
          Class<? extends RuleDefinition> ruleDefinition =
              ruleClassProvider.getRuleClassDefinition(ruleDoc.getRuleName()).getClass();
          for (Attribute attribute : ruleClass.getAttributes()) {
            String attrName = attribute.getName();
            List<RuleDocumentationAttribute> attributeDocList =
                attributeDocEntries.get(attrName);
            if (attributeDocList != null) {
              // There are attribute docs for this attribute.
              // Search the closest one in the ancestor graph.
              // Note that there can be only one 'closest' attribute since we forbid multiple
              // inheritance of the same attribute in RuleClass.
              int minLevel = Integer.MAX_VALUE;
              RuleDocumentationAttribute bestAttributeDoc = null;
              for (RuleDocumentationAttribute attributeDoc : attributeDocList) {
                int level = attributeDoc.getDefinitionClassAncestryLevel(
                    ruleDefinition,
                    ruleClassProvider);
                if (level >= 0 && level < minLevel) {
                  bestAttributeDoc = attributeDoc;
                  minLevel = level;
                }
              }
              if (bestAttributeDoc != null) {
                // Add reference to the Attribute that the attribute doc is associated with
                // in order to generate documentation for the Attribute.
                bestAttributeDoc.setAttribute(attribute);
                ruleDoc.addAttribute(bestAttributeDoc);
              // If there is no matching attribute doc try to add the common.
              } else if (ruleDoc.getRuleType().equals(RuleType.BINARY)
                  && PredefinedAttributes.BINARY_ATTRIBUTES.containsKey(attrName)) {
                ruleDoc.addAttribute(PredefinedAttributes.BINARY_ATTRIBUTES.get(attrName));
              } else if (ruleDoc.getRuleType().equals(RuleType.TEST)
                  && PredefinedAttributes.TEST_ATTRIBUTES.containsKey(attrName)) {
                ruleDoc.addAttribute(PredefinedAttributes.TEST_ATTRIBUTES.get(attrName));
              } else if (PredefinedAttributes.COMMON_ATTRIBUTES.containsKey(attrName)) {
                ruleDoc.addAttribute(PredefinedAttributes.COMMON_ATTRIBUTES.get(attrName));
              }
            }
          }
        }
      } else {
        throw ruleDoc.createException("Can't find RuleClass for " + ruleDoc.getRuleName());
      }
    }
  }

  /**
   * Crawls the specified inputPath and collects the raw rule and rule attribute documentation.
   *
   * <p>This method crawls the specified input directory (recursively calling itself for all
   * subdirectories) and reads each Java source file using {@link SourceFileReader} to extract the
   * raw rule and attribute documentation embedded in comments in a specific format. The extracted
   * documentation is then further processed, such as by
   * {@link BuildDocCollector#collect(List<String>, String, RuleLinkExpander), collect}, in order
   * to associate each rule's documentation with its attribute documentation.
   *
   * <p>This method returns the following through its parameters: the set of Java source files
   * processed, a map of rule name to the source file it was extracted from, a map of rule name
   * to the documentation to the rule, and a multimap of attribute name to attribute documentation.
   *
   * @param processedFiles The set of Java source files files that have already been processed
   *        in order to avoid reprocessing the same file.
   * @param ruleClassFiles Map of rule name to the source file it was extracted from.
   * @param ruleDocEntries Map of rule name to rule documentation.
   * @param blackList The set of blacklisted rules whose documentation should not be extracted.
   * @param attributeDocEntries Multimap of rule attribute name to attribute documentation.
   * @param inputPath The File representing the file or directory to read.
   * @throws BuildEncyclopediaDocException
   * @throws IOException
   */
  public void collectDocs(
      Set<File> processedFiles,
      Map<String, File> ruleClassFiles,
      Map<String, RuleDocumentation> ruleDocEntries,
      Set<String> blackList,
      ListMultimap<String, RuleDocumentationAttribute> attributeDocEntries,
      File inputPath) throws BuildEncyclopediaDocException, IOException {
    if (processedFiles.contains(inputPath)) {
      return;
    }

    if (inputPath.isFile()) {
      if (DocgenConsts.JAVA_SOURCE_FILE_SUFFIX.apply(inputPath.getName())) {
        SourceFileReader sfr = new SourceFileReader(ruleClassProvider, inputPath.getAbsolutePath());
        sfr.readDocsFromComments();
        for (RuleDocumentation d : sfr.getRuleDocEntries()) {
          String ruleName = d.getRuleName();
          if (!blackList.contains(ruleName)) {
            if (ruleDocEntries.containsKey(ruleName)
                && !ruleClassFiles.get(ruleName).equals(inputPath)) {
              System.err.printf(
                  "WARNING: '%s' from '%s' overrides value already in map from '%s'\n",
                  d.getRuleName(), inputPath, ruleClassFiles.get(ruleName));
            }
            ruleClassFiles.put(ruleName, inputPath);
            ruleDocEntries.put(ruleName, d);
          }
        }
        if (attributeDocEntries != null) {
          // Collect all attribute documentations from this file.
          attributeDocEntries.putAll(sfr.getAttributeDocEntries());
        }
      }
    } else if (inputPath.isDirectory()) {
      for (File childPath : inputPath.listFiles()) {
        collectDocs(processedFiles, ruleClassFiles, ruleDocEntries, blackList,
            attributeDocEntries, childPath);
      }
    }

    processedFiles.add(inputPath);
  }
}