Hello everyone, while checking CI logs I have noticed that we have lots of JavaCC warnings related to ambiguous prefixes in the productions of one of our grammars.
They also seem related to time functions, for which I have seen several related developments for BigQuery lately. Have we verified that our grammar is still behaving properly under this situation? Have we considered increasing the lookahead value as suggested? Shall we open a Jira ticket to have a closer look? Here is an example of CI logs showing the problem (although it is reproducible locally): https://ci-builds.apache.org/job/Calcite/job/Calcite-sonar/job/main/18/consoleFull In what follows the extract that is relevant to the discussion at hand: > > Task :core:javaCCMain > Java Compiler Compiler Version 4.0 (Parser Generator) > (type "javacc" with no arguments for help) > Reading from file > /home/jenkins/jenkins-agent/workspace/Calcite_Calcite-sonar_main/core/build/fmpp/fmppMain/javacc/Parser.jj > . . . > Warning: Output directory > "/home/jenkins/jenkins-agent/workspace/Calcite_Calcite-sonar_main/core/build/javacc/javaCCMain/org/apache/calcite/sql/parser/impl" > does not exist. Creating the directory. > Note: UNICODE_INPUT option is specified. Please make sure you create the > parser/lexer using a Reader with the correct character encoding. > Warning: Choice conflict involving two expansions at > line 4930, column 5 and line 4956, column 5 respectively. > A common prefix is: "MICROSECOND" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4931, column 5 and line 4956, column 5 respectively. > A common prefix is: "MILLISECOND" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4936, column 5 and line 4956, column 5 respectively. > A common prefix is: "DOW" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4937, column 5 and line 4956, column 5 respectively. > A common prefix is: "DOY" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4938, column 5 and line 4956, column 5 respectively. > A common prefix is: "ISODOW" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4939, column 5 and line 4956, column 5 respectively. > A common prefix is: "ISOYEAR" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4940, column 5 and line 4956, column 5 respectively. > A common prefix is: "WEEK" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4950, column 5 and line 4956, column 5 respectively. > A common prefix is: "QUARTER" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4952, column 5 and line 4956, column 5 respectively. > A common prefix is: "EPOCH" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4953, column 5 and line 4956, column 5 respectively. > A common prefix is: "DECADE" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4954, column 5 and line 4956, column 5 respectively. > A common prefix is: "CENTURY" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 4955, column 5 and line 4956, column 5 respectively. > A common prefix is: "MILLENNIUM" > Consider using a lookahead of 2 for earlier expansion. > Warning: Choice conflict involving two expansions at > line 6549, column 9 and line 6551, column 9 respectively. > A common prefix is: "WEEK" "(" > Consider using a lookahead of 3 or more for earlier expansion. > File "TokenMgrError.java" does not exist. Will create one. > File "ParseException.java" does not exist. Will create one. > File "Token.java" does not exist. Will create one. > File "SimpleCharStream.java" does not exist. Will create one. > Parser generated with 0 errors and 14 warnings. Best regards, Alessandro
