com.google.javascript.jscomp

Class ReplaceStrings

java.lang.Object

com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback

com.google.javascript.jscomp.ReplaceStrings

All Implemented Interfaces:

CompilerPass, NodeTraversal.Callback

class ReplaceStrings
extends NodeTraversal.AbstractPostOrderCallback
implements CompilerPass

Replaces JavaScript strings in the list of supplied methods with shortened forms. Useful for replacing debug message such as: throw new Error("Something bad happened"); with generated codes like: throw new Error("a"); This makes the compiled JavaScript smaller and prevents us from leaking details about the source code. Based in concept on the work by Jared Jacobs.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	ReplaceStrings.Config Describes a function to look for a which parameters to replace.
(package private) static class	ReplaceStrings.Result Describes a replacement that occurred.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static DiagnosticType	BAD_REPLACEMENT_CONFIGURATION
private AbstractCompiler	compiler
private static java.lang.String	DEFAULT_PLACEHOLDER_TOKEN
private java.util.Map<java.lang.String,ReplaceStrings.Config>	functions
private com.google.common.collect.Multimap<java.lang.String,java.lang.String>	methods
private DefaultNameGenerator	nameGenerator
private java.lang.String	placeholderToken
private TypeIRegistry	registry
private static java.lang.String	REPLACE_ALL_MARKER
private static java.lang.String	REPLACE_ONE_MARKER
private java.util.Map<java.lang.String,ReplaceStrings.Result>	results
(package private) static com.google.common.base.Predicate<ReplaceStrings.Result>	USED_RESULTS

Constructor Summary

Constructors

Constructor and Description
ReplaceStrings(AbstractCompiler compiler, java.lang.String placeholderToken, java.util.List<java.lang.String> functionsToInspect, java.util.Set<java.lang.String> blacklisted, VariableMap previousMappings)

Method Summary

Modifier and Type	Method and Description
private Node	buildReplacement(Node expr, Node prefix, java.lang.StringBuilder keyBuilder) Builds a replacement abstract syntax tree for the string expression expr.
private static DefaultNameGenerator	createNameGenerator(java.lang.Iterable<java.lang.String> reserved) Use a name generate to create names so the names overlap with the names used for variable and properties.
private void	doSubstitutions(NodeTraversal t, ReplaceStrings.Config config, Node n) Replace the parameters specified in the config, if possible.
private ReplaceStrings.Config	findMatching(java.lang.String name)
private ReplaceStrings.Config	findMatchingClass(TypeI callClassType, java.util.Collection<java.lang.String> declarationNames)
private static java.lang.String	getClassFromDeclarationName(java.lang.String fullDeclarationName) From a provide name extract the class name.
private static java.lang.String	getMethodFromDeclarationName(java.lang.String fullDeclarationName) From a provide name extract the method name.
private java.lang.String	getReplacement(java.lang.String key) Get a replacement string for the provide key text.
(package private) java.util.List<ReplaceStrings.Result>	getResult()
(package private) VariableMap	getStringMap()
private void	initMapping(VariableMap previousVarMap, java.util.Set<java.lang.String> reservedNames)
private void	parseConfiguration(java.util.List<java.lang.String> functionsToInspect) Build the data structures need by this pass from the provided list of functions and methods.
private ReplaceStrings.Config	parseConfiguration(java.lang.String function) Convert the provide string into a Config.
void	process(Node externs, Node root) Process the JS with root node root.
private void	recordReplacement(java.lang.String key) Record the location the replacement was made.
private Node	replaceExpression(NodeTraversal t, Node expr, Node parent) Replaces a string expression with a short encoded string expression.
void	visit(NodeTraversal t, Node n, Node parent) Visits a node in postorder (after its children have been visited).

Methods inherited from class com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback

shouldTraverse

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BAD_REPLACEMENT_CONFIGURATION

static final DiagnosticType BAD_REPLACEMENT_CONFIGURATION

DEFAULT_PLACEHOLDER_TOKEN

private static final java.lang.String DEFAULT_PLACEHOLDER_TOKEN

See Also:

Constant Field Values

placeholderToken

private final java.lang.String placeholderToken

REPLACE_ONE_MARKER

private static final java.lang.String REPLACE_ONE_MARKER

See Also:

Constant Field Values

REPLACE_ALL_MARKER

private static final java.lang.String REPLACE_ALL_MARKER

See Also:

Constant Field Values

compiler

private final AbstractCompiler compiler

registry

private final TypeIRegistry registry

functions

private final java.util.Map<java.lang.String,ReplaceStrings.Config> functions

methods

private final com.google.common.collect.Multimap<java.lang.String,java.lang.String> methods

nameGenerator

private final DefaultNameGenerator nameGenerator

results

private final java.util.Map<java.lang.String,ReplaceStrings.Result> results

USED_RESULTS

static final com.google.common.base.Predicate<ReplaceStrings.Result> USED_RESULTS

Constructor Detail

ReplaceStrings

ReplaceStrings(AbstractCompiler compiler,
               java.lang.String placeholderToken,
               java.util.List<java.lang.String> functionsToInspect,
               java.util.Set<java.lang.String> blacklisted,
               VariableMap previousMappings)

Parameters:

placeholderToken - Separator to use between string parts. Used to replace non-static string content.

functionsToInspect - A list of function configurations in the form of function($,,,) or class.prototype.method($,,,)

blacklisted - A set of names that should not be used as replacement strings. Useful to prevent unwanted strings for appearing in the final output. where '$' is used to indicate which parameter should be replaced.

Method Detail

initMapping

private void initMapping(VariableMap previousVarMap,
                         java.util.Set<java.lang.String> reservedNames)

getResult

java.util.List<ReplaceStrings.Result> getResult()

getStringMap

VariableMap getStringMap()

process

public void process(Node externs,
                    Node root)

Description copied from interface: CompilerPass

Process the JS with root node root. Can modify the contents of each Node tree

Specified by:

process in interface CompilerPass

Parameters:

externs - Top of external JS tree

root - Top of JS tree

visit

public void visit(NodeTraversal t,
                  Node n,
                  Node parent)

Description copied from interface: NodeTraversal.Callback

Visits a node in postorder (after its children have been visited). A node is visited only if all its parents should be traversed (NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node)).

Implementations can have side effects (e.g. modifying the parse tree).

Specified by:

visit in interface NodeTraversal.Callback

findMatching

private ReplaceStrings.Config findMatching(java.lang.String name)

Parameters:

name - The function name to find.

Returns:

The Config object for the name or null if no match was found.

findMatchingClass

private ReplaceStrings.Config findMatchingClass(TypeI callClassType,
                                                java.util.Collection<java.lang.String> declarationNames)

Returns:

The Config object for the class match the specified type or null if no match was found.

doSubstitutions

private void doSubstitutions(NodeTraversal t,
                             ReplaceStrings.Config config,
                             Node n)

Replace the parameters specified in the config, if possible.

replaceExpression

private Node replaceExpression(NodeTraversal t,
                               Node expr,
                               Node parent)

Replaces a string expression with a short encoded string expression.

Parameters:

t - The traversal

expr - The expression node

parent - The expression node's parent

Returns:

The replacement node (or the original expression if no replacement is made)

getReplacement

private java.lang.String getReplacement(java.lang.String key)

Get a replacement string for the provide key text.

recordReplacement

private void recordReplacement(java.lang.String key)

Record the location the replacement was made.

buildReplacement

private Node buildReplacement(Node expr,
                              Node prefix,
                              java.lang.StringBuilder keyBuilder)

Builds a replacement abstract syntax tree for the string expression expr. Appends any string literal values that are encountered to keyBuilder, to build the expression's replacement key.

Parameters:

expr - A JS expression that evaluates to a string value

prefix - The JS expression to which expr's replacement is logically being concatenated. It is a partial solution to the problem at hand and will either be this method's return value or a descendant of it.

keyBuilder - A builder of the string expression's replacement key

Returns:

The abstract syntax tree that should replace expr

getMethodFromDeclarationName

private static java.lang.String getMethodFromDeclarationName(java.lang.String fullDeclarationName)

From a provide name extract the method name.

getClassFromDeclarationName

private static java.lang.String getClassFromDeclarationName(java.lang.String fullDeclarationName)

From a provide name extract the class name.

parseConfiguration

private void parseConfiguration(java.util.List<java.lang.String> functionsToInspect)

Build the data structures need by this pass from the provided list of functions and methods.

parseConfiguration

private ReplaceStrings.Config parseConfiguration(java.lang.String function)

Convert the provide string into a Config. The string can be a static function: foo(,,?) foo.bar(?) or a class method: foo.prototype.bar(?) And is allowed to either replace all parameters using "*" or one parameter "?". "," is used as a placeholder for ignored parameters.

createNameGenerator

private static DefaultNameGenerator createNameGenerator(java.lang.Iterable<java.lang.String> reserved)

Use a name generate to create names so the names overlap with the names used for variable and properties.