antlr
Class JavaCodeGenerator

java.lang.Object
  |
  +--antlr.CodeGenerator
        |
        +--antlr.JavaCodeGenerator

public class JavaCodeGenerator

extends CodeGenerator

Untamed: Generate MyParser.java, MyLexer.java and MyParserTokenTypes.java

Field Summary

(package private) int	astVarNumber
static int	caseSizeThreshold Enabled:
(package private) String	commonExtraArgs
(package private) String	commonExtraParams
(package private) String	commonLocalVars
(package private) String	currentASTResult Tracks the rule or labeled subrule being generated.
(package private) RuleBlock	currentRule Tracks the rule being generated.
(package private) String	exceptionThrown
protected boolean	genAST
(package private) String	labeledElementASTType
(package private) String	labeledElementInit
(package private) String	labeledElementType
(package private) String	lt1Value
protected static String	NONUNIQUE Special value used to mark duplicate in treeVariableMap
protected boolean	saveText
private Vector	semPreds
protected int	syntacticPredLevel
(package private) String	throwNoViable
(package private) Hashtable	treeVariableMap Mapping between the ids used in the current alt, and the names of variables used to represent their AST values.

Fields inherited from class antlr.CodeGenerator

analyzer, behavior, bitsetsUsed, bitsetTestThreshold, charFormatter, currentOutput, DEBUG_CODE_GENERATOR, DEFAULT_BITSET_TEST_THRESHOLD, DEFAULT_MAKE_SWITCH_THRESHOLD, grammar, makeSwitchThreshold, tabs, TokenTypesFileExt, TokenTypesFileSuffix, tool

Constructor Summary

JavaCodeGenerator()
Enabled: Create a Java code-generator using the given Grammar.

Method Summary

protected int	addSemPred(String predicate) Adds a semantic predicate string to the sem pred vector These strings will be used to build an array of sem pred names when building a debugging parser.
void	exitIfError() Enabled:
void	gen() Enabled: Generate the parser, lexer, treeparser, and token types in Java
void	gen(ActionElement action) Enabled: Generate code for the given grammar element.
void	gen(AlternativeBlock blk) Enabled: Generate code for the given grammar element.
void	gen(BlockEndElement end) Enabled: Generate code for the given grammar element.
void	gen(CharLiteralElement atom) Enabled: Generate code for the given grammar element.
void	gen(CharRangeElement r) Enabled: Generate code for the given grammar element.
void	gen(LexerGrammar g) Enabled: Generate the lexer Java file
void	gen(OneOrMoreBlock blk) Enabled: Generate code for the given grammar element.
void	gen(ParserGrammar g) Enabled: Generate the parser Java file
void	gen(RuleRefElement rr) Enabled: Generate code for the given grammar element.
void	gen(StringLiteralElement atom) Enabled: Generate code for the given grammar element.
void	gen(TokenRangeElement r) Enabled: Generate code for the given grammar element.
void	gen(TokenRefElement atom) Enabled: Generate code for the given grammar element.
void	gen(TreeElement t) Enabled:
void	gen(TreeWalkerGrammar g) Enabled: Generate the tree-parser Java file
void	gen(WildcardElement wc) Enabled: Generate code for the given grammar element.
void	gen(ZeroOrMoreBlock blk) Enabled: Generate code for the given grammar element.
protected void	genAlt(Alternative alt, AlternativeBlock blk) Generate an alternative.
protected void	genBitsets(Vector bitsetList, int maxVocabulary) Generate all the bitsets to be used in the parser or lexer Generate the raw bitset data like "long _tokenSet1_data[] = {...};" and the BitSet object declarations like "BitSet _tokenSet1 = new BitSet(_tokenSet1_data);" Note that most languages do not support object initialization inside a class definition, so other code-generators may have to separate the bitset declarations from the initializations (e.g., put the initializations in the generated constructor instead).
private void	genBlockFinish(JavaBlockFinishingInfo howToFinish, String noViableAction) Generate the finish of a block, using a combination of the info returned from genCommonBlock() and the action to perform when no alts were taken
protected void	genBlockPreamble(AlternativeBlock blk) Generate the header for a block, which may be a RuleBlock or a plain AlternativeBLock.
protected void	genCases(BitSet p) Generate a series of case statements that implement a BitSet test.
JavaBlockFinishingInfo	genCommonBlock(AlternativeBlock blk, boolean noTestForSingle) Enabled: Generate common code for a block of alternatives; return a postscript that needs to be generated at the end of the block.
private void	genElementAST(AlternativeElement el) Generate code to link an element reference into the AST
private void	genErrorCatchForElement(AlternativeElement el) Close the try block and generate catch phrases if the element has a labeled handler in the rule
private void	genErrorHandler(ExceptionSpec ex) Generate the catch phrases for a user-specified error handler
private void	genErrorTryForElement(AlternativeElement el) Generate a try { opening if the element has a labeled handler in the rule
protected void	genHeader() Generate a header that is common to all Java files
private void	genLiteralsTest()
private void	genLiteralsTestForPartialToken()
protected void	genMatch(BitSet b)
protected void	genMatch(GrammarAtom atom)
protected void	genMatchUsingAtomText(GrammarAtom atom)
protected void	genMatchUsingAtomTokenType(GrammarAtom atom)
void	genNextToken() Enabled: Generate the nextToken() rule.
void	genRule(RuleSymbol s, boolean startSymbol, int ruleNum) Enabled: Gen a named rule block.
private void	GenRuleInvocation(RuleRefElement rr)
protected void	genSemPred(String pred, int line)
protected void	genSemPredMap() Write an array of Strings which are the semantic predicate expressions.
protected void	genSynPred(SynPredBlock blk, String lookaheadExpr)
void	genTokenStrings() Enabled: Generate a static array containing the names of the tokens, indexed by the token type values.
protected void	genTokenTypes(TokenManager tm) Generate the token types Java file
String	getASTCreateString(GrammarAtom atom, String str) Enabled: Get a string for an expression to generate creating of an AST node
String	getASTCreateString(String str) Enabled: Get a string for an expression to generate creating of an AST node
String	getASTCreateString(Vector v) Enabled: Get a string for an expression to generate creation of an AST subtree.
protected String	getLookaheadTestExpression(Alternative alt, int maxDepth) Generate a lookahead test expression for an alternate.
protected String	getLookaheadTestExpression(Lookahead[] look, int k)
protected String	getLookaheadTestTerm(int k, BitSet p) Generate a depth==1 lookahead test expression given the BitSet.
String	getRangeExpression(int k, int[] elems) Enabled: Return an expression for testing a contiguous renage of elements
private String	getValueString(int value) getValueString: get a string representation of a token or char value
protected boolean	lookaheadIsEmpty(Alternative alt, int maxDepth) Is the lookahead for this alt empty?
private String	lookaheadString(int k)
private String	mangleLiteral(String s) Mangle a string literal into a meaningful token name.
String	mapTreeId(String idParam, ActionTransInfo transInfo) Enabled: Map an identifier to it's corresponding tree-node variable.
private void	mapTreeVariable(AlternativeElement e, String name) Given an element and the name of an associated AST variable, create a mapping between the element "name" and the variable name.
private void	setupGrammarParameters(Grammar g)
void	setupOutput(String className) Enabled: This method exists so a subclass, namely VAJCodeGenerator, can open the file in its own evil way.
private static boolean	suitableForCaseExpression(Alternative a)

Methods inherited from class antlr.CodeGenerator

_print, _printAction, _println, elementsAreRange, extractIdOfAction, extractIdOfAction, extractTypeOfAction, extractTypeOfAction, genTokenInterchange, getBitsetName, lexerRuleName, markBitsetForGen, print, printAction, println, printTabs, processActionForTreeSpecifiers, processStringForASTConstructor, removeAssignmentFromDeclaration, reverseLexerRuleName, setAnalyzer, setBehavior, setGrammar, setTool

Methods inherited from class java.lang.Object

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

Field Detail

syntacticPredLevel

protected int syntacticPredLevel

genAST

protected boolean genAST

saveText

protected boolean saveText

labeledElementType

String labeledElementType

labeledElementASTType

String labeledElementASTType

labeledElementInit

String labeledElementInit

commonExtraArgs

String commonExtraArgs

commonExtraParams

String commonExtraParams

commonLocalVars

String commonLocalVars

lt1Value

String lt1Value

exceptionThrown

String exceptionThrown

throwNoViable

String throwNoViable

currentRule

RuleBlock currentRule

Tracks the rule being generated. Used for mapTreeId

currentASTResult

String currentASTResult

Tracks the rule or labeled subrule being generated. Used for AST generation.

treeVariableMap

Hashtable treeVariableMap

Mapping between the ids used in the current alt, and the names of variables used to represent their AST values.

astVarNumber

int astVarNumber

NONUNIQUE

protected static final String NONUNIQUE

Special value used to mark duplicate in treeVariableMap

caseSizeThreshold

public static final int caseSizeThreshold

Enabled:

semPreds

private Vector semPreds

Constructor Detail

JavaCodeGenerator

public JavaCodeGenerator()

Enabled: Create a Java code-generator using the given Grammar. The caller must still call setTool, setBehavior, and setAnalyzer before generating code.

Method Detail

addSemPred

protected int addSemPred(String predicate)

Adds a semantic predicate string to the sem pred vector These strings will be used to build an array of sem pred names when building a debugging parser. This method should only be called when the debug option is specified

exitIfError

public void exitIfError()

Enabled:

gen

public void gen()

Enabled: Generate the parser, lexer, treeparser, and token types in Java

Specified by:

gen in class CodeGenerator

gen

public void gen(ActionElement action)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

action - The {...} action to generate

gen

public void gen(AlternativeBlock blk)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

blk - The "x|y|z|..." block to generate

gen

public void gen(BlockEndElement end)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

end - The block-end element to generate. Block-end elements are synthesized by the grammar parser to represent the end of a block.

gen

public void gen(CharLiteralElement atom)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

atom - The character literal reference to generate

gen

public void gen(CharRangeElement r)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

r - The character-range reference to generate

gen

public void gen(LexerGrammar g)
         throws IOException

Enabled: Generate the lexer Java file

Specified by:

gen in class CodeGenerator

IOException

gen

public void gen(OneOrMoreBlock blk)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

blk - The (...)+ block to generate

gen

public void gen(ParserGrammar g)
         throws IOException

Enabled: Generate the parser Java file

Specified by:

gen in class CodeGenerator

IOException

gen

public void gen(RuleRefElement rr)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

rr - The rule-reference to generate

gen

public void gen(StringLiteralElement atom)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

atom - The string-literal reference to generate

gen

public void gen(TokenRangeElement r)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

r - The token-range reference to generate

gen

public void gen(TokenRefElement atom)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

atom - The token-reference to generate

gen

public void gen(TreeElement t)

Enabled:

Specified by:

gen in class CodeGenerator

gen

public void gen(TreeWalkerGrammar g)
         throws IOException

Enabled: Generate the tree-parser Java file

Specified by:

gen in class CodeGenerator

IOException

gen

public void gen(WildcardElement wc)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

wc - The wildcard element to generate

gen

public void gen(ZeroOrMoreBlock blk)

Enabled: Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

blk - The (...)* block to generate

genAlt

protected void genAlt(Alternative alt,
                      AlternativeBlock blk)

Generate an alternative.

Parameters:

alt - The alternative to generate

blk - The block to which the alternative belongs

genBitsets

protected void genBitsets(Vector bitsetList,
                          int maxVocabulary)

Generate all the bitsets to be used in the parser or lexer Generate the raw bitset data like "long _tokenSet1_data[] = {...};" and the BitSet object declarations like "BitSet _tokenSet1 = new BitSet(_tokenSet1_data);" Note that most languages do not support object initialization inside a class definition, so other code-generators may have to separate the bitset declarations from the initializations (e.g., put the initializations in the generated constructor instead).

Parameters:

bitsetList - The list of bitsets to generate.

maxVocabulary - Ensure that each generated bitset can contain at least this value.

genBlockFinish

private void genBlockFinish(JavaBlockFinishingInfo howToFinish,
                            String noViableAction)

Generate the finish of a block, using a combination of the info returned from genCommonBlock() and the action to perform when no alts were taken

Parameters:

howToFinish - The return of genCommonBlock()

noViableAction - What to generate when no alt is taken

genBlockPreamble

protected void genBlockPreamble(AlternativeBlock blk)

Generate the header for a block, which may be a RuleBlock or a plain AlternativeBLock. This generates any variable declarations, init-actions, and syntactic-predicate-testing variables.

genCases

protected void genCases(BitSet p)

Generate a series of case statements that implement a BitSet test.

Parameters:

p - The Bitset for which cases are to be generated

genCommonBlock

public JavaBlockFinishingInfo genCommonBlock(AlternativeBlock blk,
                                             boolean noTestForSingle)

Enabled: Generate common code for a block of alternatives; return a postscript that needs to be generated at the end of the block. Other routines may append else-clauses and such for error checking before the postfix is generated. If the grammar is a lexer, then generate alternatives in an order where alternatives requiring deeper lookahead are generated first, and EOF in the lookahead set reduces the depth of the lookahead. @param blk The block to generate @param noTestForSingle If true, then it does not generate a test for a single alternative.

suitableForCaseExpression

private static boolean suitableForCaseExpression(Alternative a)

genElementAST

private void genElementAST(AlternativeElement el)

Generate code to link an element reference into the AST

genErrorCatchForElement

private void genErrorCatchForElement(AlternativeElement el)

Close the try block and generate catch phrases if the element has a labeled handler in the rule

genErrorHandler

private void genErrorHandler(ExceptionSpec ex)

Generate the catch phrases for a user-specified error handler

genErrorTryForElement

private void genErrorTryForElement(AlternativeElement el)

Generate a try { opening if the element has a labeled handler in the rule

genHeader

protected void genHeader()

Generate a header that is common to all Java files

genLiteralsTest

private void genLiteralsTest()

genLiteralsTestForPartialToken

private void genLiteralsTestForPartialToken()

genMatch

protected void genMatch(BitSet b)

genMatch

protected void genMatch(GrammarAtom atom)

genMatchUsingAtomText

protected void genMatchUsingAtomText(GrammarAtom atom)

genMatchUsingAtomTokenType

protected void genMatchUsingAtomTokenType(GrammarAtom atom)

genNextToken

public void genNextToken()

Enabled: Generate the nextToken() rule. nextToken() is a synthetic lexer rule that is the implicit OR of all user-defined lexer rules.

genRule

public void genRule(RuleSymbol s,
                    boolean startSymbol,
                    int ruleNum)

Enabled: Gen a named rule block. ASTs are generated for each element of an alternative unless the rule or the alternative have a '!' modifier. If an alternative defeats the default tree construction, it must set _AST to the root of the returned AST. Each alternative that does automatic tree construction, builds up root and child list pointers in an ASTPair structure. A rule finishes by setting the returnAST variable from the ASTPair.

Parameters:

startSymbol - true if the rule is a start symbol (i.e., not referenced elsewhere)

GenRuleInvocation

private void GenRuleInvocation(RuleRefElement rr)

genSemPred

protected void genSemPred(String pred,
                          int line)

genSemPredMap

protected void genSemPredMap()

Write an array of Strings which are the semantic predicate expressions. The debugger will reference them by number only

genSynPred

protected void genSynPred(SynPredBlock blk,
                          String lookaheadExpr)

genTokenStrings

public void genTokenStrings()

Enabled: Generate a static array containing the names of the tokens, indexed by the token type values. This static array is used to format error messages so that the token identifers or literal strings are displayed instead of the token numbers. If a lexical rule has a paraphrase, use it rather than the token label.

genTokenTypes

protected void genTokenTypes(TokenManager tm)
                      throws IOException

Generate the token types Java file

IOException

getASTCreateString

public String getASTCreateString(Vector v)

Enabled: Get a string for an expression to generate creation of an AST subtree.

Specified by:

getASTCreateString in class CodeGenerator

Parameters:

v - A Vector of String, where each element is an expression in the target language yielding an AST node.

getASTCreateString

public String getASTCreateString(GrammarAtom atom,
                                 String str)

Enabled: Get a string for an expression to generate creating of an AST node

Specified by:

getASTCreateString in class CodeGenerator

Parameters:

atom - The grammar node for which you are creating the node

str - The arguments to the AST constructor

getASTCreateString

public String getASTCreateString(String str)

Enabled: Get a string for an expression to generate creating of an AST node

Parameters:

str - The arguments to the AST constructor

getLookaheadTestExpression

protected String getLookaheadTestExpression(Lookahead[] look,
                                            int k)

getLookaheadTestExpression

protected String getLookaheadTestExpression(Alternative alt,
                                            int maxDepth)

Generate a lookahead test expression for an alternate. This will be a series of tests joined by '&&' and enclosed by '()', the number of such tests being determined by the depth of the lookahead.

getLookaheadTestTerm

protected String getLookaheadTestTerm(int k,
                                      BitSet p)

Generate a depth==1 lookahead test expression given the BitSet. This may be one of: 1) a series of 'x==X||' tests 2) a range test using >= && <= where possible, 3) a bitset membership test for complex comparisons

Parameters:

k - The lookahead level

p - The lookahead set for level k

getRangeExpression

public String getRangeExpression(int k,
                                 int[] elems)

Enabled: Return an expression for testing a contiguous renage of elements

Parameters:

k - The lookahead level

elems - The elements representing the set, usually from BitSet.toArray().

Returns:

String containing test expression.

getValueString

private String getValueString(int value)

getValueString: get a string representation of a token or char value

Parameters:

value - The token or char value

lookaheadIsEmpty

protected boolean lookaheadIsEmpty(Alternative alt,
                                   int maxDepth)

Is the lookahead for this alt empty?

lookaheadString

private String lookaheadString(int k)

mangleLiteral

private String mangleLiteral(String s)

Mangle a string literal into a meaningful token name. This is only possible for literals that are all characters. The resulting mangled literal name is literalsPrefix with the text of the literal appended.

Returns:

A string representing the mangled literal, or null if not possible.

mapTreeId

public String mapTreeId(String idParam,
                        ActionTransInfo transInfo)

Enabled: Map an identifier to it's corresponding tree-node variable. This is context-sensitive, depending on the rule and alternative being generated

Specified by:

mapTreeId in class CodeGenerator

Parameters:

idParam - The identifier name to map

Returns:

The mapped id (which may be the same as the input), or null if the mapping is invalid due to duplicates

mapTreeVariable

private void mapTreeVariable(AlternativeElement e,
                             String name)

Given an element and the name of an associated AST variable, create a mapping between the element "name" and the variable name.

setupGrammarParameters

private void setupGrammarParameters(Grammar g)

setupOutput

public void setupOutput(String className)
                 throws IOException

Enabled: This method exists so a subclass, namely VAJCodeGenerator, can open the file in its own evil way. JavaCodeGenerator simply opens a text file...

IOException