Model types of elements that are missing from the classpath as ERROR types

This fixes a bug where if a class file referenced an annotation that wasn't on
the classpath, turbine would model that annotation's type as a non-ERROR type,
and then report a fatal error trying to load the missing class file. This
changes causes it to model the missing type as an ERROR type, preventing it
from incorrectly trying to access additional information about the missing
class.

PiperOrigin-RevId: 586861763

Author: cushon

java/com/google/turbine/processing/TurbineElement.java

@@ -338,10 +338,10 @@ public TypeMirror get() {
                 return factory.asTypeMirror(asGenericType(sym));
               }
 
-              ClassTy asGenericType(ClassSymbol symbol) {
+              Type asGenericType(ClassSymbol symbol) {
                 TypeBoundClass info = info();
                 if (info == null) {
-                  return ClassTy.asNonParametricClassTy(symbol);
+                  return ErrorTy.create(getQualifiedName().toString());
                 }
                 Deque<Type.ClassTy.SimpleClassTy> simples = new ArrayDeque<>();
                 simples.addFirst(simple(symbol, info));

javatests/com/google/turbine/processing/ProcessingIntegrationTest.java

@@ -37,22 +37,29 @@
 import com.google.turbine.binder.ClassPathBinder;
 import com.google.turbine.binder.Processing;
 import com.google.turbine.binder.Processing.ProcessorInfo;
+import com.google.turbine.binder.sym.ClassSymbol;
 import com.google.turbine.diag.SourceFile;
 import com.google.turbine.diag.TurbineDiagnostic;
 import com.google.turbine.diag.TurbineError;
+import com.google.turbine.diag.TurbineLog;
 import com.google.turbine.lower.IntegrationTestSupport;
 import com.google.turbine.parse.Parser;
 import com.google.turbine.testing.TestClassPaths;
 import com.google.turbine.tree.Tree;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.io.UncheckedIOException;
 import java.io.Writer;
 import java.net.URI;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarOutputStream;
 import javax.annotation.processing.AbstractProcessor;
 import javax.annotation.processing.ProcessingEnvironment;
 import javax.annotation.processing.RoundEnvironment;
@@ -62,18 +69,23 @@
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.ExecutableType;
 import javax.tools.Diagnostic;
 import javax.tools.FileObject;
 import javax.tools.JavaFileObject;
 import javax.tools.StandardLocation;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 @RunWith(JUnit4.class)
 public class ProcessingIntegrationTest {
 
+  @Rule public final TemporaryFolder temporaryFolder = new TemporaryFolder();
+
   @SupportedAnnotationTypes("*")
   public static class CrashingProcessor extends AbstractProcessor {
 
@@ -864,4 +876,74 @@ public void uriProcessing() throws IOException {
                 .map(d -> d.message()))
         .containsExactly("file:///foo/Bar - " + Paths.get(URI.create("file:///foo/Bar")));
   }
+
+  @SupportedAnnotationTypes("*")
+  public static class MethodAnnotationTypeKindProcessor extends AbstractProcessor {
+    @Override
+    public SourceVersion getSupportedSourceVersion() {
+      return SourceVersion.latestSupported();
+    }
+
+    boolean first = true;
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+      if (!first) {
+        return false;
+      }
+      first = false;
+      TypeElement e = processingEnv.getElementUtils().getTypeElement("T");
+      for (AnnotationMirror a : e.getAnnotationMirrors()) {
+        DeclaredType t = a.getAnnotationType();
+        processingEnv
+            .getMessager()
+            .printMessage(Diagnostic.Kind.NOTE, t + "(" + t.getKind() + ")", e);
+        // this shouldn't crash
+        requireNonNull(a.getAnnotationType().asElement().getEnclosedElements());
+      }
+      return false;
+    }
+  }
+
+  @Test
+  public void missingAnnotationType() throws IOException {
+    Map<String, byte[]> library =
+        IntegrationTestSupport.runTurbine(
+            ImmutableMap.of(
+                "A.java", //
+                "@interface A {}",
+                "T.java",
+                "@A class T {}"),
+            ImmutableList.of());
+    Path libJar = temporaryFolder.newFile("lib.jar").toPath();
+    try (OutputStream os = Files.newOutputStream(libJar);
+        JarOutputStream jos = new JarOutputStream(os)) {
+      // deliberately exclude the definition of the annotation
+      jos.putNextEntry(new JarEntry("T.class"));
+      jos.write(requireNonNull(library.get("T")));
+    }
+
+    ImmutableList<Tree.CompUnit> units =
+        parseUnit(
+            "=== Y.java ===", //
+            "class Y {}");
+
+    TurbineLog log = new TurbineLog();
+    BindingResult bound =
+        Binder.bind(
+            log,
+            units,
+            ClassPathBinder.bindClasspath(ImmutableList.of(libJar)),
+            ProcessorInfo.create(
+                ImmutableList.of(new MethodAnnotationTypeKindProcessor()),
+                getClass().getClassLoader(),
+                ImmutableMap.of(),
+                SourceVersion.latestSupported()),
+            TestClassPaths.TURBINE_BOOTCLASSPATH,
+            Optional.empty());
+    assertThat(bound.units().keySet()).containsExactly(new ClassSymbol("Y"));
+    ImmutableList<String> messages =
+        log.diagnostics().stream().map(TurbineDiagnostic::message).collect(toImmutableList());
+    assertThat(messages).containsExactly("A(ERROR)");
+  }
 }