[plsql] Refactor ExtractExpression

* Separate helper productions for datetime/xml
* Use StringLiteral for xpath and namespace

pmd-plsql/etc/grammar/PldocAST.jjt

@@ -27,6 +27,10 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 /**
+ * Add support for XMLROOT, improve ExtractExpression to support xml
+ *
+ * Piotr Szymanski 03/2020
+ *====================================================================
  * Add basic support for with clause in select statements
  *
  * Andreas Dangel 09/2019
@@ -3241,7 +3245,16 @@ ASTUnaryExpression UnaryExpression(boolean isUnarySign) #UnaryExpression(>1) :
 ASTExtractExpression ExtractExpression() :
 {}
 {
-    LOOKAHEAD(4)
+    LOOKAHEAD(4) ExtractDatetime() { return jjtThis ; }
+    |
+    LOOKAHEAD(3) ExtractXml(jjtThis) { return jjtThis ; }
+}
+
+/**
+ * See https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf/EXTRACT-datetime.html#GUID-36E52BF8-945D-437D-9A3C-6860CABD210E
+ */
+void ExtractDatetime() #void : {}
+{
     <EXTRACT> "("
         ( <MONTH> | <YEAR> | <DAY> |<HOUR> | <MINUTE> | <SECOND>
         | <TIMEZONE_HOUR> | <TIMEZONE_MINUTE>
@@ -3254,10 +3267,17 @@ ASTExtractExpression ExtractExpression() :
             |
             LOOKAHEAD(Name()) Name()
             ) ")"
-        { return jjtThis ; }
-    |
-    LOOKAHEAD(3)  <EXTRACT> "(" Argument() "," Expression() ["," SchemaName() ] ")"
-    { return jjtThis ; }
+}
+
+/**
+ * See https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf/EXTRACT-XML.html#GUID-593295AA-4F46-4D75-B8DC-E7BCEDB1D4D7
+ */
+void ExtractXml(ASTExtractExpression extractExpr) #void :
+{
+    extractExpr.setXml();
+}
+{
+    <EXTRACT> "(" Argument() "," StringLiteral() ["," StringLiteral() ] ")"
 }
 
 ASTUnaryExpressionNotPlusMinus UnaryExpressionNotPlusMinus() #UnaryExpressionNotPlusMinus(>1) :

pmd-plsql/src/main/ant/alljavacc.xml

@@ -47,6 +47,7 @@
         <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTComparisonCondition.java" />
         <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTCompoundCondition.java" />
         <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTDatatype.java" />
+        <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTExtractExpression.java" />
         <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTFormalParameter.java" />
         <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTIfStatement.java" />
         <delete file="${target}/net/sourceforge/pmd/lang/plsql/ast/ASTInnerCrossJoinClause.java" />

pmd-plsql/src/main/java/net/sourceforge/pmd/lang/plsql/ast/ASTExtractExpression.java

@@ -0,0 +1,57 @@
+/*
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.plsql.ast;
+
+import java.util.List;
+
+import net.sourceforge.pmd.annotation.InternalApi;
+
+public final class ASTExtractExpression extends AbstractPLSQLNode {
+
+    private boolean xml;
+
+    @InternalApi
+    @Deprecated
+    public ASTExtractExpression(int id) {
+        super(id);
+    }
+
+
+    @InternalApi
+    @Deprecated
+    public ASTExtractExpression(PLSQLParser p, int id) {
+        super(p, id);
+    }
+
+
+    public Object jjtAccept(PLSQLParserVisitor visitor, Object data) {
+        return visitor.visit(this, data);
+    }
+
+    void setXml() {
+        xml = true;
+    }
+
+    public boolean isXml() {
+        return xml;
+    }
+
+    public String getXPath() {
+        if (xml) {
+            return getFirstChildOfType(ASTStringLiteral.class).getString();
+        }
+        return "";
+    }
+
+    public String getNamespace() {
+        if (xml) {
+            List<ASTStringLiteral> literals = findChildrenOfType(ASTStringLiteral.class);
+            if (literals.size() == 2) {
+                return literals.get(1).getString();
+            }
+        }
+        return "";
+    }
+}

pmd-plsql/src/test/java/net/sourceforge/pmd/lang/plsql/ast/ASTExtractExpressionTest.java

@@ -0,0 +1,26 @@
+/*
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.plsql.ast;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import net.sourceforge.pmd.lang.plsql.PlsqlParsingHelper;
+
+public class ASTExtractExpressionTest {
+
+
+    @Test
+    public void testXml() {
+        PlsqlParsingHelper parser = PlsqlParsingHelper.JUST_PARSE;
+        ASTInput unit = parser.parse("SELECT warehouse_name, EXTRACT(warehouse_spec, '/Warehouse/Docks', "
+                + "'xmlns:a=\"http://warehouse/1\" xmlns:b=\"http://warehouse/2\"') \"Number of Docks\" "
+                + " FROM warehouses WHERE warehouse_spec IS NOT NULL;");
+        ASTExtractExpression extract = unit.getFirstDescendantOfType(ASTExtractExpression.class);
+        Assert.assertTrue(extract.isXml());
+        Assert.assertEquals("/Warehouse/Docks", extract.getXPath());
+        Assert.assertEquals("xmlns:a=\"http://warehouse/1\" xmlns:b=\"http://warehouse/2\"", extract.getNamespace());
+    }
+}

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

@@ -8,7 +8,13 @@ SELECT warehouse_name, EXTRACT(warehouse_spec, '/Warehouse/Docks')
    "Number of Docks"
    FROM warehouses
    WHERE warehouse_spec IS NOT NULL;
-   
+
+SELECT warehouse_name, EXTRACT(warehouse_spec, '/Warehouse/Docks', 'xmlns:a="http://warehouse/1" xmlns:b="http://warehouse/2"')
+   "Number of Docks"
+   FROM warehouses
+   WHERE warehouse_spec IS NOT NULL;
+
+
 SELECT XMLELEMENT("Emp", 
    XMLFOREST(e.employee_id, e.last_name, e.salary))
    "Emp Element"