[plsql] Parsing exception "Less than or equal to/Greater than or equal to" operators in DML statements

[hgodinez89]

Affects PMD Version:

This error was testing in the following versions:

• 6.41.0
• 6.40.0
• 6.39.0

Description:

Trying to analyze pl/sql code that has "Less than or equal to/Greater than or equal to" operators (<=; >=), but these operators have a blank space between two characters, for instance > = or < =, PMD raises an exception error indicating "Error while parsing".

Note: This is totally correct in DML statements for Oracle databases engines.

Exception Stacktrace:

net.sourceforge.pmd.PMDException: Error while parsing C:\testfolder\example_procedure.prc
	at net.sourceforge.pmd.SourceCodeProcessor.processSourceCodeWithoutCache(SourceCodeProcessor.java:124)
	at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode(SourceCodeProcessor.java:100)
	at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode(SourceCodeProcessor.java:62)
	at net.sourceforge.pmd.processor.PmdRunnable.call(PmdRunnable.java:85)
	at net.sourceforge.pmd.processor.PmdRunnable.call(PmdRunnable.java:29)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: net.sourceforge.pmd.lang.plsql.ast.ParseException: Encountered " "=" "= "" at line 10, column 23.
Was expecting one of:
    "LOG" ...
    "(" ...
    "REF" ...
    "LAST" ...
    "*" ...
    "+" ...
    "OVER" ...
    "UNBOUNDED" ...
    "PRECEDING" ...
    ...
    "TRIM" ...
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.generateParseException(PLSQLParser.java)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.jj_consume_token(PLSQLParser.java)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.UnaryExpression(PLSQLParser.java:41132)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.MultiplicativeExpression(PLSQLParser.java:40679)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.AdditiveExpression(PLSQLParser.java:40565)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.SqlExpression(PLSQLParser.java:13560)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.ComparisonCondition(PLSQLParser.java:12848)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition2(PLSQLParser.java:12165)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12703)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12675)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12697)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12675)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12697)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12697)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12675)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12724)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12724)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CompoundCondition(PLSQLParser.java:12724)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Condition(PLSQLParser.java:11754)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.WhereClause(PLSQLParser.java:11712)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.RestOfStatement(PLSQLParser.java:10606)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.SelectStatement(PLSQLParser.java:28448)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CursorUnit(PLSQLParser.java:38877)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.CursorSpecification(PLSQLParser.java:38919)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.DeclarativeUnit(PLSQLParser.java:2728)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.DeclarativeSection(PLSQLParser.java:3154)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.ProgramUnit(PLSQLParser.java:6446)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Global(PLSQLParser.java:879)
	at net.sourceforge.pmd.lang.plsql.ast.PLSQLParser.Input(PLSQLParser.java:153)
	at net.sourceforge.pmd.lang.plsql.PLSQLParser.parse(PLSQLParser.java:61)
	at net.sourceforge.pmd.lang.AbstractParser.doParse(AbstractParser.java:44)
	at net.sourceforge.pmd.SourceCodeProcessor.parse(SourceCodeProcessor.java:136)
	at net.sourceforge.pmd.SourceCodeProcessor.processSource(SourceCodeProcessor.java:200)
	at net.sourceforge.pmd.SourceCodeProcessor.processSourceCodeWithoutCache(SourceCodeProcessor.java:118)
	... 10 more

Code Sample demonstrating the issue:

CREATE OR REPLACE PROCEDURE EXAMPLE_PROCEDURE IS
   --
   l_total_objects NUMBER(10);
   --
BEGIN
   --
   SELECT COUNT(1)
     INTO l_total_objects
     FROM USER_OBJECTS
    WHERE namespace < = 1
       OR namespace > = 0;
   --
   DBMS_OUTPUT.Put_Line('Total number of objects: ' || l_total_objects);
   --
END EXAMPLE_PROCEDURE;

Note: By removing all the blank spaces in the operators in the SELECT statement, you will have no parsing problems.

Steps to reproduce:

1. Put the code above ("Code Sample demonstrating the issue" section) in example_procedure.prc
2. Execute PMD analyzer from CLI.
3. See the error showed in the "Exception Stacktrace" section.

Running PMD through: [CLI]

[oowekyala]

Do you know if there can be a newline or comments between the two symbols, or just spaces?

[hgodinez89]

Very good question @oowekyala. Yes, you can. Oracle allows you to put not just spaces, you can put new lines, even comments between the two symbols, and the database engine compiles the routine correctly.

[oowekyala]

In that case I believe it would be enough to lex <= and such as two tokens < and =. I'm not sure what would be the fallout of this on the parser (lookaheads might need adjustments).

[hgodinez89]

I am not sure about your comment @oowekyala, is it possible to fix it in PMD parser?

[oowekyala]

Yes, this was more of a note to myself