src/main/java/com/google/devtools/build/docgen/RuleLinkExpander.java - bazel - Git at Google

 // 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.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import java.nio.file.Paths;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.regex.Matcher;

 /**
  * Helper class used for expanding link references in rule and attribute documentation.
  *
  * <p>See {@link com.google.devtools.build.docgen.DocgenConsts.BLAZE_RULE_LINK} for the regex used
  * to match link references.
  */
 // TODO(fwe): rename to LinkExpander
 // TODO(fwe): prefix rule links with BE root?
 public class RuleLinkExpander {
   private static final String EXAMPLES_SUFFIX = "_examples";
   private static final String ARGS_SUFFIX = "_args";
   private static final String IMPLICIT_OUTPUTS_SUFFIX = "_implicit_outputs";
   private static final String FUNCTIONS_PAGE = "functions";

   private static final ImmutableMap<String, String> FUNCTIONS =
       ImmutableMap.<String, String>builder()
           .put("load", FUNCTIONS_PAGE)
           .put("package", FUNCTIONS_PAGE)
           .put("package_group", FUNCTIONS_PAGE)
           .put("description", FUNCTIONS_PAGE)
           .put("distribs", FUNCTIONS_PAGE)
           .put("licenses", FUNCTIONS_PAGE)
           .put("exports_files", FUNCTIONS_PAGE)
           .put("glob", FUNCTIONS_PAGE)
           .put("select", FUNCTIONS_PAGE)
           .buildOrThrow();

   // These static pages only exist in the multi-page BE. In the single-page BE
   // their content is part of the BE.
   private static final ImmutableSet<String> STATIC_PAGES_REPLACED_BY_SINGLE_PAGE_BE =
       ImmutableSet.<String>of("common-definitions", "make-variables");

   private final DocLinkMap linkMap;
   private final Map<String, String> ruleIndex = new HashMap<>();
   private final boolean singlePage;

   RuleLinkExpander(Map<String, String> ruleIndex, boolean singlePage, DocLinkMap linkMap) {
     this.ruleIndex.putAll(ruleIndex);
     this.ruleIndex.putAll(FUNCTIONS);
     this.singlePage = singlePage;
     this.linkMap = linkMap;
   }

   RuleLinkExpander(boolean singlePage, DocLinkMap linkMap) {
     this.ruleIndex.putAll(FUNCTIONS);
     this.singlePage = singlePage;
     this.linkMap = linkMap;
   }

   public String beRoot() {
     return linkMap.beRoot;
   }

   public void addIndex(Map<String, String> ruleIndex) {
     this.ruleIndex.putAll(ruleIndex);
   }

   private void appendRuleLink(Matcher matcher, StringBuffer sb, String ruleName, String ref) {
     String ruleFamily = ruleIndex.get(ruleName);
     String link =
         singlePage
             ? "#" + ref
             : Paths.get(linkMap.beRoot, String.format("%s.html#%s", ruleFamily, ref)).toString();
     matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
   }

   /*
    * Match and replace all ${link rule.attribute} references.
    */
   private String expandRuleLinks(String htmlDoc) throws IllegalArgumentException {
     Matcher matcher = DocgenConsts.BLAZE_RULE_LINK.matcher(htmlDoc);
     StringBuffer sb = new StringBuffer(htmlDoc.length());
     while (matcher.find()) {
       // The first capture group matches the entire reference, e.g. "cc_binary.deps".
       String ref = matcher.group(1);
       // The second capture group only matches the rule name, e.g. "cc_binary" in "cc_binary.deps".
       String name = matcher.group(2);

       // The name in the reference is the name of a rule. Get the rule family for the rule and
       // replace the reference with a link with the form of rule-family.html#rule.attribute. For
       // example, ${link cc_library.deps} expands to c-cpp.html#cc_library.deps.
       if (ruleIndex.containsKey(name)) {
         appendRuleLink(matcher, sb, name, ref);
         continue;
       }

       // The name is referencing the examples, arguments, or implicit outputs of a rule (e.g.
       // "cc_library_args", "cc_library_examples", or "java_binary_implicit_outputs"). Strip the
       // suffix and then try matching the name to a rule family.
       if (name.endsWith(EXAMPLES_SUFFIX)
           || name.endsWith(ARGS_SUFFIX)
           || name.endsWith(IMPLICIT_OUTPUTS_SUFFIX)) {
         int endIndex;
         if (name.endsWith(EXAMPLES_SUFFIX)) {
           endIndex = name.indexOf(EXAMPLES_SUFFIX);
         } else if (name.endsWith(ARGS_SUFFIX)) {
           endIndex = name.indexOf(ARGS_SUFFIX);
         } else {
           endIndex = name.indexOf(IMPLICIT_OUTPUTS_SUFFIX);
         }
         String ruleName = name.substring(0, endIndex);
         if (ruleIndex.containsKey(ruleName)) {
           appendRuleLink(matcher, sb, ruleName, ref);
           continue;
         }
       }

       // The name is not the name of a rule but is the name of a static page, such as
       // common-definitions. Generate a link to that page.
       String mapping = linkMap.values.get(name);
       if (mapping != null) {
         String link =
             singlePage && STATIC_PAGES_REPLACED_BY_SINGLE_PAGE_BE.contains(name)
                 ? "#" + name
                 : mapping;
         // For referencing headings on a static page, use the following syntax:
         // ${link static_page_name#heading_name}, example: ${link make-variables#gendir}
         String pageHeading = matcher.group(4);
         if (pageHeading != null) {
           throw new IllegalArgumentException(
               "Invalid link syntax for BE page: " + matcher.group()
               + "\nUse ${link static-page#heading} syntax instead.");
         }
         matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
         continue;
       }

       // If the reference does not match any rule or static page, throw an exception.
       throw new IllegalArgumentException(
           "Rule family " + name + " in link tag does not match any rule or BE page: "
           + matcher.group());
     }
     matcher.appendTail(sb);
     return sb.toString();
   }

   /*
    * Match and replace all ${link rule#heading} references.
    */
   private String expandRuleHeadingLinks(String htmlDoc) throws IllegalArgumentException {
     Matcher matcher = DocgenConsts.BLAZE_RULE_HEADING_LINK.matcher(htmlDoc);
     StringBuffer sb = new StringBuffer(htmlDoc.length());
     while (matcher.find()) {
       // The first capture group matches the entire reference, e.g. "cc_library#some_heading".
       String ref = matcher.group(1);
       // The second capture group only matches the rule name, e.g. "cc_library" in
       // "cc_library#some_heading"
       String name = matcher.group(2);
       // The third capture group only matches the heading, e.g. "some_heading" in
       // "cc_library#some_heading"
       String heading = matcher.group(3);

       // The name in the reference is the name of a rule. Get the rule family for the rule and
       // replace the reference with the link in the form of rule-family.html#heading. Examples of
       // this include custom <a name="heading"> tags in the description or examples for the rule.
       if (ruleIndex.containsKey(name)) {
         String ruleFamily = ruleIndex.get(name);
         String link = singlePage
             ? "#" + heading
             : ruleFamily + ".html#" + heading;
         matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
         continue;
       }

       // The name is of a static page, such as common.definitions. Generate a link to that page, and
       // append the page heading. For example, ${link common-definitions#label-expansion} expands to
       // common-definitions.html#label-expansion.

       // We need to search for the entire match first since some documentation files have a 1:n
       // relation between Blaze and Bazel. Example: build-ref#labels points to build-ref.html#labels
       // for Blaze, but to /concepts/labels for Bazel. However, we have to consider whether a single
       // heading or the entire page has to be redirected.

       // Not-null if page#heading has a mapping (other headings on the page are unaffected):
       String headingMapping = linkMap.values.get(ref);
       // Not-null if the entire page has a mapping, i.e. all headings should be redirected:
       String pageMapping = linkMap.values.get(name);

       if (headingMapping != null || pageMapping != null) {
         String link;
         if (singlePage && STATIC_PAGES_REPLACED_BY_SINGLE_PAGE_BE.contains(name)) {
           // Special case: Some of the stand-alone files in the multi-page BE are made redundant
           // by the BE in the single-page case. Consequently, we ignore the value of the mapping
           // in this case (we only need to know that the mapping exists, since this means it is
           // a legitimate reference).
           link = "#" + heading;
         } else if (headingMapping != null) {
           // Multi-page BE where page#heading has to be redirected.
           link = headingMapping;
         } else { // pageMapping != null
           // Multi-page BE where the entire page has to be forwarded (but the new page has
           // identical headings).
           link = String.format("%s#%s", pageMapping, heading);
         }

         matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
         continue;
       }

       // If the reference does not match any rule or static page, throw an exception.
       throw new IllegalArgumentException(
           "Rule family " + name + " in link tag does not match any rule or BE page: "
           + matcher.group());
     }
     matcher.appendTail(sb);
     return sb.toString();
   }

   /**
    * Expands all rule references in the input HTML documentation.
    *
    * @param htmlDoc The input HTML documentation with ${link foo.bar} references.
    * @return The HTML documentation with all link references expanded.
    */
   public String expand(String htmlDoc) throws IllegalArgumentException {
     String expanded = expandRuleLinks(htmlDoc);
     return expandRuleHeadingLinks(expanded);
   }

   /**
    * Expands the rule reference.
    *
    * <p>This method is used to expand references in the BE velocity templates.
    *
    * @param ref The rule reference to expand.
    * @return The expanded rule reference.
    */
   public String expandRef(String ref) throws IllegalArgumentException {
     return expand("${link " + ref + "}");
   }
 }
	// 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.collect.ImmutableMap;
	import com.google.common.collect.ImmutableSet;
	import java.nio.file.Paths;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.regex.Matcher;

	/**
	* Helper class used for expanding link references in rule and attribute documentation.
	*
	* <p>See {@link com.google.devtools.build.docgen.DocgenConsts.BLAZE_RULE_LINK} for the regex used
	* to match link references.
	*/
	// TODO(fwe): rename to LinkExpander
	// TODO(fwe): prefix rule links with BE root?
	public class RuleLinkExpander {
	private static final String EXAMPLES_SUFFIX = "_examples";
	private static final String ARGS_SUFFIX = "_args";
	private static final String IMPLICIT_OUTPUTS_SUFFIX = "_implicit_outputs";
	private static final String FUNCTIONS_PAGE = "functions";

	private static final ImmutableMap<String, String> FUNCTIONS =
	ImmutableMap.<String, String>builder()
	.put("load", FUNCTIONS_PAGE)
	.put("package", FUNCTIONS_PAGE)
	.put("package_group", FUNCTIONS_PAGE)
	.put("description", FUNCTIONS_PAGE)
	.put("distribs", FUNCTIONS_PAGE)
	.put("licenses", FUNCTIONS_PAGE)
	.put("exports_files", FUNCTIONS_PAGE)
	.put("glob", FUNCTIONS_PAGE)
	.put("select", FUNCTIONS_PAGE)
	.buildOrThrow();

	// These static pages only exist in the multi-page BE. In the single-page BE
	// their content is part of the BE.
	private static final ImmutableSet<String> STATIC_PAGES_REPLACED_BY_SINGLE_PAGE_BE =
	ImmutableSet.<String>of("common-definitions", "make-variables");

	private final DocLinkMap linkMap;
	private final Map<String, String> ruleIndex = new HashMap<>();
	private final boolean singlePage;

	RuleLinkExpander(Map<String, String> ruleIndex, boolean singlePage, DocLinkMap linkMap) {
	this.ruleIndex.putAll(ruleIndex);
	this.ruleIndex.putAll(FUNCTIONS);
	this.singlePage = singlePage;
	this.linkMap = linkMap;
	}

	RuleLinkExpander(boolean singlePage, DocLinkMap linkMap) {
	this.ruleIndex.putAll(FUNCTIONS);
	this.singlePage = singlePage;
	this.linkMap = linkMap;
	}

	public String beRoot() {
	return linkMap.beRoot;
	}

	public void addIndex(Map<String, String> ruleIndex) {
	this.ruleIndex.putAll(ruleIndex);
	}

	private void appendRuleLink(Matcher matcher, StringBuffer sb, String ruleName, String ref) {
	String ruleFamily = ruleIndex.get(ruleName);
	String link =
	singlePage
	? "#" + ref
	: Paths.get(linkMap.beRoot, String.format("%s.html#%s", ruleFamily, ref)).toString();
	matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
	}

	/*
	* Match and replace all ${link rule.attribute} references.
	*/
	private String expandRuleLinks(String htmlDoc) throws IllegalArgumentException {
	Matcher matcher = DocgenConsts.BLAZE_RULE_LINK.matcher(htmlDoc);
	StringBuffer sb = new StringBuffer(htmlDoc.length());
	while (matcher.find()) {
	// The first capture group matches the entire reference, e.g. "cc_binary.deps".
	String ref = matcher.group(1);
	// The second capture group only matches the rule name, e.g. "cc_binary" in "cc_binary.deps".
	String name = matcher.group(2);

	// The name in the reference is the name of a rule. Get the rule family for the rule and
	// replace the reference with a link with the form of rule-family.html#rule.attribute. For
	// example, ${link cc_library.deps} expands to c-cpp.html#cc_library.deps.
	if (ruleIndex.containsKey(name)) {
	appendRuleLink(matcher, sb, name, ref);
	continue;
	}

	// The name is referencing the examples, arguments, or implicit outputs of a rule (e.g.
	// "cc_library_args", "cc_library_examples", or "java_binary_implicit_outputs"). Strip the
	// suffix and then try matching the name to a rule family.
	if (name.endsWith(EXAMPLES_SUFFIX)
	\|\| name.endsWith(ARGS_SUFFIX)
	\|\| name.endsWith(IMPLICIT_OUTPUTS_SUFFIX)) {
	int endIndex;
	if (name.endsWith(EXAMPLES_SUFFIX)) {
	endIndex = name.indexOf(EXAMPLES_SUFFIX);
	} else if (name.endsWith(ARGS_SUFFIX)) {
	endIndex = name.indexOf(ARGS_SUFFIX);
	} else {
	endIndex = name.indexOf(IMPLICIT_OUTPUTS_SUFFIX);
	}
	String ruleName = name.substring(0, endIndex);
	if (ruleIndex.containsKey(ruleName)) {
	appendRuleLink(matcher, sb, ruleName, ref);
	continue;
	}
	}

	// The name is not the name of a rule but is the name of a static page, such as
	// common-definitions. Generate a link to that page.
	String mapping = linkMap.values.get(name);
	if (mapping != null) {
	String link =
	singlePage && STATIC_PAGES_REPLACED_BY_SINGLE_PAGE_BE.contains(name)
	? "#" + name
	: mapping;
	// For referencing headings on a static page, use the following syntax:
	// ${link static_page_name#heading_name}, example: ${link make-variables#gendir}
	String pageHeading = matcher.group(4);
	if (pageHeading != null) {
	throw new IllegalArgumentException(
	"Invalid link syntax for BE page: " + matcher.group()
	+ "\nUse ${link static-page#heading} syntax instead.");
	}
	matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
	continue;
	}

	// If the reference does not match any rule or static page, throw an exception.
	throw new IllegalArgumentException(
	"Rule family " + name + " in link tag does not match any rule or BE page: "
	+ matcher.group());
	}
	matcher.appendTail(sb);
	return sb.toString();
	}

	/*
	* Match and replace all ${link rule#heading} references.
	*/
	private String expandRuleHeadingLinks(String htmlDoc) throws IllegalArgumentException {
	Matcher matcher = DocgenConsts.BLAZE_RULE_HEADING_LINK.matcher(htmlDoc);
	StringBuffer sb = new StringBuffer(htmlDoc.length());
	while (matcher.find()) {
	// The first capture group matches the entire reference, e.g. "cc_library#some_heading".
	String ref = matcher.group(1);
	// The second capture group only matches the rule name, e.g. "cc_library" in
	// "cc_library#some_heading"
	String name = matcher.group(2);
	// The third capture group only matches the heading, e.g. "some_heading" in
	// "cc_library#some_heading"
	String heading = matcher.group(3);

	// The name in the reference is the name of a rule. Get the rule family for the rule and
	// replace the reference with the link in the form of rule-family.html#heading. Examples of
	// this include custom <a name="heading"> tags in the description or examples for the rule.
	if (ruleIndex.containsKey(name)) {
	String ruleFamily = ruleIndex.get(name);
	String link = singlePage
	? "#" + heading
	: ruleFamily + ".html#" + heading;
	matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
	continue;
	}

	// The name is of a static page, such as common.definitions. Generate a link to that page, and
	// append the page heading. For example, ${link common-definitions#label-expansion} expands to
	// common-definitions.html#label-expansion.

	// We need to search for the entire match first since some documentation files have a 1:n
	// relation between Blaze and Bazel. Example: build-ref#labels points to build-ref.html#labels
	// for Blaze, but to /concepts/labels for Bazel. However, we have to consider whether a single
	// heading or the entire page has to be redirected.

	// Not-null if page#heading has a mapping (other headings on the page are unaffected):
	String headingMapping = linkMap.values.get(ref);
	// Not-null if the entire page has a mapping, i.e. all headings should be redirected:
	String pageMapping = linkMap.values.get(name);

	if (headingMapping != null \|\| pageMapping != null) {
	String link;
	if (singlePage && STATIC_PAGES_REPLACED_BY_SINGLE_PAGE_BE.contains(name)) {
	// Special case: Some of the stand-alone files in the multi-page BE are made redundant
	// by the BE in the single-page case. Consequently, we ignore the value of the mapping
	// in this case (we only need to know that the mapping exists, since this means it is
	// a legitimate reference).
	link = "#" + heading;
	} else if (headingMapping != null) {
	// Multi-page BE where page#heading has to be redirected.
	link = headingMapping;
	} else { // pageMapping != null
	// Multi-page BE where the entire page has to be forwarded (but the new page has
	// identical headings).
	link = String.format("%s#%s", pageMapping, heading);
	}

	matcher.appendReplacement(sb, Matcher.quoteReplacement(link));
	continue;
	}

	// If the reference does not match any rule or static page, throw an exception.
	throw new IllegalArgumentException(
	"Rule family " + name + " in link tag does not match any rule or BE page: "
	+ matcher.group());
	}
	matcher.appendTail(sb);
	return sb.toString();
	}

	/**
	* Expands all rule references in the input HTML documentation.
	*
	* @param htmlDoc The input HTML documentation with ${link foo.bar} references.
	* @return The HTML documentation with all link references expanded.
	*/
	public String expand(String htmlDoc) throws IllegalArgumentException {
	String expanded = expandRuleLinks(htmlDoc);
	return expandRuleHeadingLinks(expanded);
	}

	/**
	* Expands the rule reference.
	*
	* <p>This method is used to expand references in the BE velocity templates.
	*
	* @param ref The rule reference to expand.
	* @return The expanded rule reference.
	*/
	public String expandRef(String ref) throws IllegalArgumentException {
	return expand("${link " + ref + "}");
	}
	}