Allow excluding lines from the parser using comments -- PMD-EXCLUDE-BEGIN and -- PMD-EXCLUDE-END. This is to workaround bugs in the PL/SQL parser - some valid statements cannot be parsed. by wrapping them inside PMD-EXCLUDE-BEGIN/END the parser just ignores them and continues parsing with the next line.

pmd-plsql/etc/grammar/PldocAST.jjt

@@ -3416,7 +3416,7 @@ ASTPrimaryPrefix PrimaryPrefix() :
 | LOOKAHEAD(Literal()) ( simpleNode = Literal() ) { sb.append(simpleNode.getImage()) ; }
 | LOOKAHEAD(SimpleExpression()) ( simpleNode = SimpleExpression() ) { sb.append(simpleNode.getImage()); }
 | ( simpleNode =Name() ) { sb.append(simpleNode.getImage()) ; }
-| SelectStatement()
+// | SelectStatement()
 | LOOKAHEAD("(" <SELECT>) "(" SelectStatement() ")"
 | LOOKAHEAD(<WITH>) (<WITH>) {sb.append("WITH ..."); }  Skip2NextTerminator(null,";")
 | LOOKAHEAD(("(")+ <WITH>) ("(") {sb.append("(WITH ..."); }  Skip2NextTerminator("(",")") ")"
@@ -4593,6 +4593,51 @@ SKIP :
 	" " | "\t" | "\f"
 }
 
+/* 
+This Grammar (or JavaCC) has several bugs.
+
+Currently (2021-02-26) it fails for things like
+- dbms_lob.trim(...),
+- scalar subqueries in the WHERE-clause,
+- TREAT(object AS type),
+just to name a few.
+
+Running PMD over a code base of approx. 1100 DDL scripts
+from a commercial product, the parser failed for 182 files.
+About 10% of these parsing errors actually showed flaws in the code,
+e.g. "\u2013" instead of "-", or utf-8 encoding instead of windows-1252
+(which is the standard for the product's scripts).
+Still, ~ 15% of perfectly valid DDL scripts could not be parsed by PMD.
+
+Nevertheless it should be best practice to call PMD for _every_ DDL script.
+
+Thus, we introduce the following workaround to cope with the situation.
+We introduce two special comments PMD-EXCLUDE-BEGIN and PMD-EXCLUDE-END
+which cause PMD to treat the source inbetween these comments more or less
+like a multi-line comment, or in other words, just not try to parse them.
+
+It is good practice to include a reason for excluding inside the
+-- PMD-EXCUDE-BEGIN comment.
+
+The PMD-EXCLUDE-BEGIN and PMD-EXLUDE-END comment lines must not contain
+other statements, e.g. do_xy(); -- PMD-EXCLUDE-BEGIN is invalid.
+
+Example:
+
+begin
+  do_something();
+  -- PMD-EXCLUDE-BEGIN: PMD does not like dbms_lob.trim (clash with TrimExpression)
+  dbms_lob.trim(the_blob, 1000);
+  -- PMD-EXCLUDE-END
+  do_something_else();
+end;
+
+A future version of PMD might pass the existence of the exclusion to the AST
+as an "ASTParsingExclusion" statement, perhaps including the comment and the
+excluded source, to allow for detecting this workaround with a rule.
+But for now, it is just skipped.
+*/
+
 /* COMMENTS */
 
 MORE :
@@ -4600,6 +4645,14 @@ MORE :
 	<"/**" ~["/"]> : IN_FORMAL_COMMENT
 |
 	"/*" : IN_MULTI_LINE_COMMENT
+| 
+  <"--" (" ")* "PMD-EXCLUDE-BEGIN" (" ")* (":")? (" ")* (~["\n", "\r"])*> : IN_PARSING_EXCLUSION
+}
+
+<IN_PARSING_EXCLUSION>
+SPECIAL_TOKEN :
+{
+  	<PARSING_EXCLUSION: "--" (" ")* "PMD-EXCLUDE-END" (~["\n", "\r"])* > : DEFAULT
 }
 
 SPECIAL_TOKEN :
@@ -4635,7 +4688,7 @@ SKIP :
 */
 
 <IN_FORMAL_COMMENT, IN_MULTI_LINE_COMMENT,
- IN_SQL_STATEMENT_ENDED_SEMICOLON>
+ IN_SQL_STATEMENT_ENDED_SEMICOLON, IN_PARSING_EXCLUSION>
 MORE :
 {
 	< ~[] >

pmd-plsql/src/test/resources/net/sourceforge/pmd/lang/plsql/ast/IsOfType.pls

@@ -17,7 +17,7 @@ IF ioFPOobj IS NOT OF TYPE (ONLY FPOGE_OBJ) THEN
 loFPOGE_OBJ:=treat(ioFPOobj AS FPOGE_OBJ);
 end if;
 
-loFPOGE_OBJ:=SELECT A FROM persons p WHERE VALUE(p) IS OF TYPE (employee_t);
+SELECT A into lo_FPOGE_OBJ FROM persons p WHERE VALUE(p) IS OF TYPE (employee_t);
-loFPOGE_OBJ:=SELECT A FROM persons p WHERE VALUE(p) IS NOT OF TYPE (ONLY employee_t, other_t);
+SELECT A into lo_FPOGE_OBJ FROM persons p WHERE VALUE(p) IS NOT OF TYPE (ONLY employee_t, other_t);
 
 end;