forked from jasder/antlr
added check: action in lexer rules must be last element of outermost alt
This commit is contained in:
parent
5e519d0063
commit
e86f89724f
|
@ -3,6 +3,7 @@ ANTLR v4 Honey Badger
|
|||
November 17, 2012
|
||||
|
||||
* .tokens files goes in output dir like parser file.
|
||||
* added check: action in lexer rules must be last element of outermost alt
|
||||
|
||||
November 11, 2012
|
||||
|
||||
|
|
|
@ -1,8 +1,8 @@
|
|||
grammar T;
|
||||
s : ~(ID|X)* X ;
|
||||
b : ~(ID|X)*? X ;
|
||||
A : 'a' ;
|
||||
B : 'b' ;
|
||||
X : 'x' ;
|
||||
ID : 'id' ;
|
||||
s : A ;
|
||||
|
||||
A : {} 'a' ;
|
||||
|
||||
B : ('x' {}|{}'y') {} ;
|
||||
|
||||
WS : [ \t\r\n]+ -> skip ;
|
||||
|
|
|
@ -30,6 +30,8 @@
|
|||
package org.antlr.v4.semantics;
|
||||
|
||||
import org.antlr.runtime.Token;
|
||||
import org.antlr.runtime.tree.CommonTree;
|
||||
import org.antlr.runtime.tree.Tree;
|
||||
import org.antlr.v4.misc.Utils;
|
||||
import org.antlr.v4.parse.ANTLRParser;
|
||||
import org.antlr.v4.parse.GrammarTreeVisitor;
|
||||
|
@ -322,6 +324,28 @@ public class BasicSemanticChecks extends GrammarTreeVisitor {
|
|||
}
|
||||
}
|
||||
|
||||
@Override
|
||||
protected void enterLexerElement(GrammarAST tree) {
|
||||
if ( tree.getType() == ACTION ) {
|
||||
// Make sure that action is last element in outer alt; here action
|
||||
// and a2 are bad, but a3 is ok.
|
||||
// (RULE A (BLOCK (ALT {action} 'a')))
|
||||
// (RULE B (BLOCK (ALT (BLOCK (ALT {a2} 'x') (ALT 'y')) {a3})))
|
||||
CommonTree alt = tree.parent;
|
||||
CommonTree blk = alt.parent;
|
||||
boolean outerMostAlt = blk.parent.getType() != RULE;
|
||||
Tree rule = tree.getAncestor(RULE);
|
||||
String fileName = tree.getToken().getInputStream().getSourceName();
|
||||
if ( !outerMostAlt || tree.getChildIndex() != alt.getChildCount()-1 ) {
|
||||
g.tool.errMgr.grammarError(ErrorType.LEXER_ACTION_PLACEMENT_ISSUE,
|
||||
fileName,
|
||||
tree.getToken(),
|
||||
rule.getChild(0).getText());
|
||||
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@Override
|
||||
public void label(GrammarAST op, GrammarAST ID, GrammarAST element) {
|
||||
switch (element.getType()) {
|
||||
|
|
|
@ -153,6 +153,7 @@ public enum ErrorType {
|
|||
// WILDCARD_IN_PARSER(129, "wildcard '.' not allowed in parsers", ErrorSeverity.ERROR),
|
||||
LABEL_BLOCK_NOT_A_SET(130, "label <arg> assigned to a block which is not a set", ErrorSeverity.ERROR),
|
||||
EXPECTED_NON_GREEDY_WILDCARD_BLOCK(131, "greedy block ()<arg> contains wildcard; the non-greedy syntax ()<arg>? may be preferred", ErrorSeverity.WARNING),
|
||||
LEXER_ACTION_PLACEMENT_ISSUE(132, "action in lexer rule <arg> must be last element of outermost alt", ErrorSeverity.ERROR),
|
||||
|
||||
/** Documentation comment is unterminated */
|
||||
//UNTERMINATED_DOC_COMMENT(, "", ErrorSeverity.ERROR),
|
||||
|
|
Loading…
Reference in New Issue