org.antlr.v4.codegen

Class Target

java.lang.Object

org.antlr.v4.codegen.Target

Direct Known Subclasses:

CppTarget, CSharpTarget, GoTarget, JavaScriptTarget, JavaTarget, PHPTarget, Python2Target, Python3Target, SwiftTarget

public abstract class Target
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
protected CodeGenerator	gen
protected String[]	targetCharValueEscape For pure strings of Java 16-bit Unicode char, how can we display it in the target language as a literal.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Target(CodeGenerator gen, String language)

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract void	appendUnicodeEscapedCodePoint(int codePoint, StringBuilder sb) Escape the Unicode code point appropriately for this language and append the escaped value to sb.
String	encodeIntAsCharEscape(int v) Assume 16-bit char
protected void	genFile(Grammar g, org.stringtemplate.v4.ST outputFileST, String fileName)
String	getAltLabelContextStructName(String label)
String	getBaseListenerFileName(boolean header) A given grammar T, return a blank listener implementation such as TBaseListener.java, if we're using the Java target.
String	getBaseVisitorFileName(boolean header) A given grammar T, return a blank listener implementation such as TBaseListener.java, if we're using the Java target.
CodeGenerator	getCodeGenerator()
String	getElementListName(String name)
String	getElementName(String name)
String	getImplicitRuleLabel(String ruleName)
String	getImplicitSetLabel(String id)
String	getImplicitTokenLabel(String tokenName)
int	getInlineTestSetWordSize() How many bits should be used to do inline token type tests? Java assumes a 64-bit word for bitsets.
String	getLanguage()
String	getListenerFileName(boolean header) A given grammar T, return the listener name such as TListener.java, if we're using the Java target.
String	getListLabel(String label)
String	getLoopCounter(GrammarAST ast)
String	getLoopLabel(GrammarAST ast)
String	getRecognizerFileName(boolean header) Generate TParser.java and TLexer.java from T.g4 if combined, else just use T.java as output regardless of type.
String	getRuleFunctionContextStructName(Rule r)
String	getRuleFunctionContextStructName(RuleFunction function) If we know which actual function, we can provide the actual ctx type.
int	getSerializedATNSegmentLimit() Gets the maximum number of 16-bit unsigned integers that can be encoded in a single segment of the serialized ATN.
String	getTargetStringLiteralFromANTLRStringLiteral(CodeGenerator generator, String literal, boolean addQuotes) Convert from an ANTLR string literal found in a grammar file to an equivalent string literal in the target language.
String	getTargetStringLiteralFromString(String s)
String	getTargetStringLiteralFromString(String s, boolean quoted) Given a random string of Java unicode chars, return a new string with optionally appropriate quote characters for target language and possibly with some escaped characters.
org.stringtemplate.v4.STGroup	getTemplates()
String	getTokenTypeAsTargetLabel(Grammar g, int ttype) Get a meaningful name for a token type useful during code generation.
String[]	getTokenTypesAsTargetLabels(Grammar g, int[] ttypes)
abstract String	getVersion() ANTLR tool should check output templates / target are compatible with tool code generation.
String	getVisitorFileName(boolean header) A given grammar T, return the visitor name such as TVisitor.java, if we're using the Java target.
boolean	grammarSymbolCausesIssueInGeneratedCode(GrammarAST idNode)
protected org.stringtemplate.v4.STGroup	loadTemplates()
boolean	needsHeader()
boolean	supportsOverloadedMethods()
boolean	templatesExist()
protected abstract boolean	visibleGrammarSymbolCausesIssueInGeneratedCode(GrammarAST idNode)
boolean	wantsBaseListener()
boolean	wantsBaseVisitor()

Methods inherited from class java.lang.Object

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

Field Detail

targetCharValueEscape

protected String[] targetCharValueEscape

For pure strings of Java 16-bit Unicode char, how can we display it in the target language as a literal. Useful for dumping predicates and such that may refer to chars that need to be escaped when represented as strings. Also, templates need to be escaped so that the target language can hold them as a string.

I have defined (via the constructor) the set of typical escapes, but your Target subclass is free to alter the translated chars or add more definitions. This is non-static so each target can have a different set in memory at same time.

gen

protected final CodeGenerator gen

Constructor Detail

Target

protected Target(CodeGenerator gen,
      String language)

Method Detail

getCodeGenerator

public CodeGenerator getCodeGenerator()

getLanguage

public String getLanguage()

getVersion

public abstract String getVersion()

ANTLR tool should check output templates / target are compatible with tool code generation. For now, a simple string match used on x.y of x.y.z scheme. We use a method to avoid mismatches between a template called VERSION. This value is checked against Tool.VERSION during load of templates. This additional method forces all targets 4.3 and beyond to add this method.

Since:

4.3

getTemplates

public org.stringtemplate.v4.STGroup getTemplates()

genFile

protected void genFile(Grammar g,
           org.stringtemplate.v4.ST outputFileST,
           String fileName)

getTokenTypeAsTargetLabel

public String getTokenTypeAsTargetLabel(Grammar g,
                               int ttype)

Get a meaningful name for a token type useful during code generation. Literals without associated names are converted to the string equivalent of their integer values. Used to generate x==ID and x==34 type comparisons etc... Essentially we are looking for the most obvious way to refer to a token type in the generated code.

getTokenTypesAsTargetLabels

public String[] getTokenTypesAsTargetLabels(Grammar g,
                                   int[] ttypes)

getTargetStringLiteralFromString

public String getTargetStringLiteralFromString(String s,
                                      boolean quoted)

Given a random string of Java unicode chars, return a new string with optionally appropriate quote characters for target language and possibly with some escaped characters. For example, if the incoming string has actual newline characters, the output of this method would convert them to the two char sequence \n for Java, C, C++, ... The new string has double-quotes around it as well. Example String in memory: a"[newlinechar]b'c[carriagereturnchar]d[tab]e\f would be converted to the valid Java s: "a\"\nb'c\rd\te\\f" or a\"\nb'c\rd\te\\f depending on the quoted arg.

appendUnicodeEscapedCodePoint

protected abstract void appendUnicodeEscapedCodePoint(int codePoint,
                                 StringBuilder sb)

Escape the Unicode code point appropriately for this language and append the escaped value to sb.

getTargetStringLiteralFromString

public String getTargetStringLiteralFromString(String s)

getTargetStringLiteralFromANTLRStringLiteral

public String getTargetStringLiteralFromANTLRStringLiteral(CodeGenerator generator,
                                                  String literal,
                                                  boolean addQuotes)

Convert from an ANTLR string literal found in a grammar file to an equivalent string literal in the target language.

For Java, this is the translation 'a\n"' → "a\n\"". Expect single quotes around the incoming literal. Just flip the quotes and replace double quotes with \".

Note that we have decided to allow people to use '\"' without penalty, so we must build the target string in a loop as String.replace(char, char) cannot handle both \" and " without a lot of messing around.

encodeIntAsCharEscape

public String encodeIntAsCharEscape(int v)

Assume 16-bit char

getLoopLabel

public String getLoopLabel(GrammarAST ast)

getLoopCounter

public String getLoopCounter(GrammarAST ast)

getListLabel

public String getListLabel(String label)

getRuleFunctionContextStructName

public String getRuleFunctionContextStructName(Rule r)

getAltLabelContextStructName

public String getAltLabelContextStructName(String label)

getRuleFunctionContextStructName

public String getRuleFunctionContextStructName(RuleFunction function)

If we know which actual function, we can provide the actual ctx type. This will contain implicit labels etc... From outside, though, we see only ParserRuleContext unless there are externally visible stuff like args, locals, explicit labels, etc...

getImplicitTokenLabel

public String getImplicitTokenLabel(String tokenName)

getImplicitSetLabel

public String getImplicitSetLabel(String id)

getImplicitRuleLabel

public String getImplicitRuleLabel(String ruleName)

getElementListName

public String getElementListName(String name)

getElementName

public String getElementName(String name)

getRecognizerFileName

public String getRecognizerFileName(boolean header)

Generate TParser.java and TLexer.java from T.g4 if combined, else just use T.java as output regardless of type.

getListenerFileName

public String getListenerFileName(boolean header)

A given grammar T, return the listener name such as TListener.java, if we're using the Java target.

getVisitorFileName

public String getVisitorFileName(boolean header)

A given grammar T, return the visitor name such as TVisitor.java, if we're using the Java target.

getBaseListenerFileName

public String getBaseListenerFileName(boolean header)

A given grammar T, return a blank listener implementation such as TBaseListener.java, if we're using the Java target.

getBaseVisitorFileName

public String getBaseVisitorFileName(boolean header)

A given grammar T, return a blank listener implementation such as TBaseListener.java, if we're using the Java target.

getSerializedATNSegmentLimit

public int getSerializedATNSegmentLimit()

Gets the maximum number of 16-bit unsigned integers that can be encoded in a single segment of the serialized ATN.

Returns:

the serialized ATN segment limit

See Also:

SerializedATN.getSegments()

getInlineTestSetWordSize

public int getInlineTestSetWordSize()

How many bits should be used to do inline token type tests? Java assumes a 64-bit word for bitsets. Must be a valid wordsize for your target like 8, 16, 32, 64, etc...

Since:

4.5

grammarSymbolCausesIssueInGeneratedCode

public boolean grammarSymbolCausesIssueInGeneratedCode(GrammarAST idNode)

visibleGrammarSymbolCausesIssueInGeneratedCode

protected abstract boolean visibleGrammarSymbolCausesIssueInGeneratedCode(GrammarAST idNode)

templatesExist

public boolean templatesExist()

loadTemplates

protected org.stringtemplate.v4.STGroup loadTemplates()

wantsBaseListener

public boolean wantsBaseListener()

Since:

4.3

wantsBaseVisitor

public boolean wantsBaseVisitor()

Since:

4.3

supportsOverloadedMethods

public boolean supportsOverloadedMethods()

Since:

4.3

needsHeader

public boolean needsHeader()

Since:

4.6