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


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