Turn many semantic errors into warnings

pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/SemanticErrorReporter.java

@@ -34,7 +34,9 @@ public interface SemanticErrorReporter {
 
     /**
      * Report a warning at the given location. Warnings do not abort
-     * the analysis.
+     * the analysis. They are usually recoverable errors. They are used
+     * to warn the user that something wrong is going on, which may cause
+     * subsequent errors or inconsistent behavior.
      *
      * @param location   Location where the warning should be reported
      * @param message    Message (rendered using a {@link MessageFormat})
@@ -44,9 +46,9 @@ public interface SemanticErrorReporter {
 
 
     /**
-     * Report an error at the given location. Errors abort subsequent analysis.
-     * The produced error can be thrown by the caller if it cannot be recovered
-     * from.
+     * Report an error at the given location. Errors abort subsequent analysis
+     * and cause a processing error to be put in the report. The produced error
+     * can be thrown by the caller if it cannot be recovered from.
      *
      * @param location   Location where the error should be reported
      * @param message    Message (rendered using a {@link MessageFormat})

pmd-core/src/test/java/net/sourceforge/pmd/lang/ast/SemanticErrorReporterTest.java

@@ -4,12 +4,15 @@
 
 package net.sourceforge.pmd.lang.ast;
 
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.contains;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -36,6 +39,7 @@ public class SemanticErrorReporterTest {
     @Before
     public void setup() {
         mockReporter = mock(MessageReporter.class);
+        when(mockReporter.isLoggable(Level.ERROR)).thenReturn(true);
         mockLogger = spy(NOPLogger.class);
     }
 
@@ -44,11 +48,15 @@ public class SemanticErrorReporterTest {
         SemanticErrorReporter reporter = SemanticErrorReporter.reportToLogger(mockReporter, mockLogger);
         RootNode node = parseMockNode(reporter);
 
+        assertFalse(reporter.hasError());
+
         String message = "an error occurred";
         reporter.error(node, message);
 
         verify(mockReporter).log(eq(Level.ERROR), contains(message));
         verifyNoMoreInteractions(mockLogger);
+
+        assertTrue(reporter.hasError());
     }
 
     @Test

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/AstDisambiguationPass.java

@@ -211,7 +211,7 @@ final class AstDisambiguationPass {
             JTypeDeclSymbol sym = type.getReferencedSym();
             if (type.getParent() instanceof ASTAnnotation) {
                 if (!(sym instanceof JClassSymbol && (sym.isUnresolved() || ((JClassSymbol) sym).isAnnotation()))) {
-                    ctx.getLogger().error(type, JavaSemanticErrors.EXPECTED_ANNOTATION_TYPE);
+                    ctx.getLogger().warning(type, JavaSemanticErrors.EXPECTED_ANNOTATION_TYPE);
                 }
                 return;
             }
@@ -219,7 +219,7 @@ final class AstDisambiguationPass {
             int actualArity = ASTList.sizeOrZero(type.getTypeArguments());
             int expectedArity = sym instanceof JClassSymbol ? ((JClassSymbol) sym).getTypeParameterCount() : 0;
             if (actualArity != 0 && actualArity != expectedArity) {
-                ctx.getLogger().error(type, JavaSemanticErrors.MALFORMED_GENERIC_TYPE, expectedArity, actualArity);
+                ctx.getLogger().warning(type, JavaSemanticErrors.MALFORMED_GENERIC_TYPE, expectedArity, actualArity);
             }
         }
 

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/InternalApiBridge.java

@@ -98,7 +98,7 @@ public final class InternalApiBridge {
                 try {
                     it.getTypeMirror();
                 } catch (Exception e) {
-                    processor.getLogger().error(it, "Error during type resolution of node " + it.getXPathNodeName());
+                    processor.getLogger().warning(it, "Error during type resolution of node " + it.getXPathNodeName());
                 }
             });
     }

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symbols/table/internal/ReferenceCtx.java

@@ -90,7 +90,7 @@ public final class ReferenceCtx {
             if (distinct.size() == 1) {
                 return distinct.iterator().next();
             }
-            processor.getLogger().error(
+            processor.getLogger().warning(
                 errorLocation,
                 AMBIGUOUS_NAME_REFERENCE,
                 name,

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/types/ast/LazyTypeResolver.java

@@ -564,7 +564,7 @@ public final class LazyTypeResolver extends JavaVisitorBase<TypingContext, @NonN
         JMethodSig m = lambda.getFunctionalMethod(); // this forces resolution of the lambda
         if (!isUnresolved(m)) {
             if (m.getArity() != node.getOwner().getArity()) {
-                err.error(node.getOwner(), "Lambda shape does not conform to the functional method {0}", m);
+                err.warning(node.getOwner(), "Lambda shape does not conform to the functional method {0}", m);
                 return ts.ERROR;
             }
             return m.getFormalParameters().get(node.getIndexInParent());