antlr
Class JavaCodeGenerator

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

public class JavaCodeGenerator

extends CodeGenerator

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

Field Summary

static int	caseSizeThreshold
protected boolean	genAST
protected static String	NONUNIQUE Special value used to mark duplicate in treeVariableMap
protected boolean	saveText
protected int	syntacticPredLevel

Fields inherited from class antlr.CodeGenerator

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

Constructor Summary

JavaCodeGenerator()
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()
void	gen() Generate the parser, lexer, treeparser, and token types in Java
void	gen(antlr.ActionElement action) Generate code for the given grammar element.
void	gen(antlr.AlternativeBlock blk) Generate code for the given grammar element.
void	gen(antlr.BlockEndElement end) Generate code for the given grammar element.
void	gen(antlr.CharLiteralElement atom) Generate code for the given grammar element.
void	gen(antlr.CharRangeElement r) Generate code for the given grammar element.
void	gen(antlr.LexerGrammar g) Generate the lexer Java file
void	gen(antlr.OneOrMoreBlock blk) Generate code for the given grammar element.
void	gen(antlr.ParserGrammar g) Generate the parser Java file
void	gen(antlr.RuleRefElement rr) Generate code for the given grammar element.
void	gen(antlr.StringLiteralElement atom) Generate code for the given grammar element.
void	gen(antlr.TokenRangeElement r) Generate code for the given grammar element.
void	gen(antlr.TokenRefElement atom) Generate code for the given grammar element.
void	gen(antlr.TreeElement t) Generate code for the given grammar element.
void	gen(antlr.TreeWalkerGrammar g) Generate the tree-parser Java file
void	gen(antlr.WildcardElement wc) Generate code for the given grammar element.
void	gen(antlr.ZeroOrMoreBlock blk) Generate code for the given grammar element.
protected void	genAlt(antlr.Alternative alt, antlr.AlternativeBlock blk) Generate an alternative.
protected void	genASTDeclaration(antlr.AlternativeElement el)
protected void	genASTDeclaration(antlr.AlternativeElement el, String node_type)
protected void	genASTDeclaration(antlr.AlternativeElement el, String var_name, String node_type)
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).
protected void	genBlockInitAction(antlr.AlternativeBlock blk) Generate the init action for a block, which may be a RuleBlock or a plain AlternativeBLock.
protected void	genBlockPreamble(antlr.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.
antlr.JavaBlockFinishingInfo	genCommonBlock(antlr.AlternativeBlock blk, boolean noTestForSingle) Generate common code for a block of alternatives; return a postscript that needs to be generated at the end of the block.
protected void	genHeader() Generate a header that is common to all Java files
protected void	genMatch(BitSet b)
protected void	genMatch(antlr.GrammarAtom atom)
protected void	genMatchUsingAtomText(antlr.GrammarAtom atom)
protected void	genMatchUsingAtomTokenType(antlr.GrammarAtom atom)
void	genNextToken() Generate the nextToken() rule.
void	genRule(antlr.RuleSymbol s, boolean startSymbol, int ruleNum) Gen a named rule block.
protected void	genSemPred(String pred, int line)
protected void	genSemPredMap() Write an array of Strings which are the semantic predicate expressions.
protected void	genSynPred(antlr.SynPredBlock blk, String lookaheadExpr)
protected void	genTokenASTNodeMap() Create and set Integer token type objects that map to Java Class objects (which AST node to create).
void	genTokenStrings() Generate a static array containing the names of the tokens, indexed by the token type values.
protected void	genTokenTypes(antlr.TokenManager tm) Generate the token types Java file
String	getASTCreateString(antlr.GrammarAtom atom, String astCtorArgs) Get a string for an expression to generate creating of an AST node
String	getASTCreateString(String astCtorArgs) Get a string for an expression to generate creating of an AST node.
String	getASTCreateString(Vector v) Get a string for an expression to generate creation of an AST subtree.
protected String	getLookaheadTestExpression(antlr.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) Return an expression for testing a contiguous renage of elements
protected boolean	lookaheadIsEmpty(antlr.Alternative alt, int maxDepth) Is the lookahead for this alt empty?
String	mapTreeId(String idParam, ActionTransInfo transInfo) Map an identifier to it's corresponding tree-node variable.
protected String	processActionForSpecialSymbols(String actionStr, int line, RuleBlock currentRule, ActionTransInfo tInfo) Lexically process $var and tree-specifiers in the action.
void	setupOutput(String className) This method exists so a subclass, namely VAJCodeGenerator, can open the file in its own evil way.

Methods inherited from class antlr.CodeGenerator

_print, _printAction, _println, decodeLexerRuleName, elementsAreRange, encodeLexerRuleName, extractIdOfAction, extractIdOfAction, extractTypeOfAction, extractTypeOfAction, genTokenInterchange, getBitsetName, getFIRSTBitSet, getFOLLOWBitSet, markBitsetForGen, print, printAction, println, printTabs, 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

NONUNIQUE

protected static final String NONUNIQUE

Special value used to mark duplicate in treeVariableMap

caseSizeThreshold

public static final int caseSizeThreshold

See Also:

Constant Field Values

Constructor Detail

JavaCodeGenerator

public JavaCodeGenerator()

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()

gen

public void gen()

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

Specified by:

gen in class CodeGenerator

gen

public void gen(antlr.ActionElement action)

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

action - The {...} action to generate

gen

public void gen(antlr.AlternativeBlock blk)

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(antlr.BlockEndElement end)

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(antlr.CharLiteralElement atom)

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(antlr.CharRangeElement r)

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(antlr.LexerGrammar g)
         throws IOException

Generate the lexer Java file

Specified by:

gen in class CodeGenerator

IOException

gen

public void gen(antlr.OneOrMoreBlock blk)

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

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

gen

public void gen(antlr.ParserGrammar g)
         throws IOException

Generate the parser Java file

Specified by:

gen in class CodeGenerator

IOException

gen

public void gen(antlr.RuleRefElement rr)

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

rr - The rule-reference to generate

gen

public void gen(antlr.StringLiteralElement atom)

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(antlr.TokenRangeElement r)

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(antlr.TokenRefElement atom)

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

atom - The token-reference to generate

gen

public void gen(antlr.TreeElement t)

Description copied from class: CodeGenerator

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

gen

public void gen(antlr.TreeWalkerGrammar g)
         throws IOException

Generate the tree-parser Java file

Specified by:

gen in class CodeGenerator

IOException

gen

public void gen(antlr.WildcardElement wc)

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

wc - The wildcard element to generate

gen

public void gen(antlr.ZeroOrMoreBlock blk)

Generate code for the given grammar element.

Specified by:

gen in class CodeGenerator

Parameters:

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

genAlt

protected void genAlt(antlr.Alternative alt,
                      antlr.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.

genBlockInitAction

protected void genBlockInitAction(antlr.AlternativeBlock blk)

Generate the init action for a block, which may be a RuleBlock or a plain AlternativeBLock.

genBlockPreamble

protected void genBlockPreamble(antlr.AlternativeBlock blk)

Generate the header for a block, which may be a RuleBlock or a plain AlternativeBLock. This generates any variable declarations 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 antlr.JavaBlockFinishingInfo genCommonBlock(antlr.AlternativeBlock blk,
                                                   boolean noTestForSingle)

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.

genASTDeclaration

protected void genASTDeclaration(antlr.AlternativeElement el)

genASTDeclaration

protected void genASTDeclaration(antlr.AlternativeElement el,
                                 String node_type)

genASTDeclaration

protected void genASTDeclaration(antlr.AlternativeElement el,
                                 String var_name,
                                 String node_type)

genHeader

protected void genHeader()

Generate a header that is common to all Java files

genMatch

protected void genMatch(BitSet b)

genMatch

protected void genMatch(antlr.GrammarAtom atom)

genMatchUsingAtomText

protected void genMatchUsingAtomText(antlr.GrammarAtom atom)

genMatchUsingAtomTokenType

protected void genMatchUsingAtomTokenType(antlr.GrammarAtom atom)

genNextToken

public void genNextToken()

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(antlr.RuleSymbol s,
                    boolean startSymbol,
                    int ruleNum)

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)

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(antlr.SynPredBlock blk,
                          String lookaheadExpr)

genTokenStrings

public void genTokenStrings()

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.

genTokenASTNodeMap

protected void genTokenASTNodeMap()

Create and set Integer token type objects that map to Java Class objects (which AST node to create).

genTokenTypes

protected void genTokenTypes(antlr.TokenManager tm)
                      throws IOException

Generate the token types Java file

IOException

getASTCreateString

public String getASTCreateString(Vector v)

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(antlr.GrammarAtom atom,
                                 String astCtorArgs)

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

astCtorArgs - The text of the arguments to the AST construction

getASTCreateString

public String getASTCreateString(String astCtorArgs)

Get a string for an expression to generate creating of an AST node. Parse the first (possibly only) argument looking for the token type. If the token type is a valid token symbol, ask for it's AST node type and add to the end if only 2 arguments. The forms are #[T], #[T,"t"], and as of 2.7.2 #[T,"t",ASTclassname].

getLookaheadTestExpression

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

getLookaheadTestExpression

protected String getLookaheadTestExpression(antlr.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)

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.

lookaheadIsEmpty

protected boolean lookaheadIsEmpty(antlr.Alternative alt,
                                   int maxDepth)

Is the lookahead for this alt empty?

mapTreeId

public String mapTreeId(String idParam,
                        ActionTransInfo transInfo)

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

processActionForSpecialSymbols

protected String processActionForSpecialSymbols(String actionStr,
                                                int line,
                                                RuleBlock currentRule,
                                                ActionTransInfo tInfo)

Lexically process $var and tree-specifiers in the action. This will replace #id and #(...) with the appropriate function calls and/or variables etc...

Specified by:

processActionForSpecialSymbols in class CodeGenerator

setupOutput

public void setupOutput(String className)
                 throws IOException

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

IOException