Warning while building

[Alainvdh]

while compiling i have a lot of warning
Is it normal or how can i avoid them ?

Thank you in advance
Alain

[INFO] --- exec-maven-plugin:1.1:exec (default) @ lexer-parser ---
[INFO] two-threaded DFA conversion
[INFO] two-threaded DFA conversion
[INFO] warning(200): C:\Java\eclipseIndigo32\workspace\porcelli\lexer-parser/src/main/antlr3/br/com/porcelli/parser/plsql/PLSQLParser.g:825:55: Decision can match input such as "SQL92_RESERVED_DECLARE" using multiple alternatives: 1, 3
[INFO] As a result, alternative(s) 3 were disabled for that input
[INFO] warning(200): C:\Java\eclipseIndigo32\workspace\porcelli\lexer-parser/src/main/antlr3/br/com/porcelli/parser/plsql/PLSQLParser.g:825:55: Decision can match input such as "INTRODUCER" using multiple alternatives: 1, 3
[INFO] As a result, alternative(s) 3 were disabled for that input
[INFO] warning(200): C:\Java\eclipseIndigo32\workspace\porcelli\lexer-parser/src/main/antlr3/br/com/porcelli/parser/plsql/PLSQLParser.g:825:55: Decision can match input such as "SQL92_RESERVED_WITH" using multiple alternatives: 1, 3
[INFO] As a result, alternative(s) 3 were disabled for that input
[INFO] warning(203): C:\Java\eclipseIndigo32\workspace\porcelli\lexer-parser/src/main/antlr3/br/com/porcelli/parser/plsql/PLSQLParser.g:825:55: Input such as "REGULAR_ID" is insufficiently covered with predicates at locations: alt 1: line 383:5 at BLOCK, alt 3: line 383:5 at BLOCK
[INFO] warning(200): C:\Java\eclipseIndigo32\workspace\porcelli\lexer-parser/src/main/antlr3/br/com/porcelli/parser/plsql/PLSQLParser.g:825:55: Decision can match input such as "REGULAR_ID" using multiple alternatives: 1, 3
[INFO] As a result, alternative(s) 3 were disabled for that input

[adrian-wang]

This is caused by ambiguity of the grammar. Antlr will take default action by choose the first possible alternative.