chore: unify ValuePool exceptions

Author: oetr

src/main/java/com/code_intelligence/jazzer/mutation/support/ValuePoolRegistry.java

@@ -19,7 +19,6 @@
 import static com.code_intelligence.jazzer.mutation.support.Preconditions.require;
 
 import com.code_intelligence.jazzer.mutation.annotation.ValuePool;
-import com.code_intelligence.jazzer.utils.Log;
 import java.io.IOException;
 import java.lang.reflect.AnnotatedType;
 import java.lang.reflect.InvocationTargetException;
@@ -102,9 +101,9 @@ public Stream<?> extractUserValues(AnnotatedType type) {
                   Supplier<Stream<?>> supplier = pools.get(name);
                   if (supplier == null) {
                     throw new IllegalStateException(
-                        "No method named '"
+                        "@ValuePool: No method named '"
                             + name
-                            + "' found for @ValuePool on type "
+                            + "' found for type "
                             + type.getType().getTypeName()
                             + " in fuzz test method "
                             + fuzzTestMethod.getName()
@@ -136,9 +135,9 @@ private Stream<byte[]> extractByteArraysFromPatterns(AnnotatedType type) {
               List<Path> paths = GlobUtils.collectPathsForGlob(baseDir, glob);
               if (paths.isEmpty()) {
                 throw new IllegalStateException(
-                    "No files matched glob pattern '"
+                    "@ValuePool: No files matched glob pattern '"
                         + glob
-                        + "' for @ValuePool on type "
+                        + "' for type "
                         + type.getType().getTypeName()
                         + " in fuzz test method "
                         + fuzzTestMethod.getName()
@@ -193,8 +192,10 @@ public Stream<?> get() {
             }
           }
           if (cachedData.isEmpty()) {
-            Log.warn("@ValuePool method " + method.getName() + " provided no values.");
-            return Stream.empty();
+            throw new IllegalStateException(
+                "@ValuePool: method '"
+                    + method.getName()
+                    + "' returned no values. Value pool methods must return at least one value.");
           }
         }
         return cachedData.stream();
@@ -208,9 +209,12 @@ private static List<Object> loadDataFromMethod(Method method) {
       Stream<?> stream = (Stream<?>) method.invoke(null);
       return stream.collect(Collectors.toList());
     } catch (IllegalAccessException e) {
-      throw new IllegalStateException("Cannot access method " + method.getName(), e);
+      throw new RuntimeException("@ValuePool: Access denied for method " + method.getName(), e);
     } catch (InvocationTargetException e) {
-      throw new RuntimeException("Error invoking method " + method.getName(), e.getCause());
+      Throwable cause = e.getCause();
+      throw new RuntimeException(
+          "@ValuePool: Method " + method.getName() + " threw an exception",
+          cause != null ? cause : e);
     }
   }
 }