From 7491f1805a04299bbcaef14df95aad735b409856 Mon Sep 17 00:00:00 2001
From: Steve Hannah <steve@weblite.ca>
Date: Fri, 24 Mar 2017 15:47:55 -0700
Subject: [PATCH] Added annotation to suppress errors like * claimed to be
 synchronous, but has invocations of synchronous methods.  This is usesful in
 cases where the developer knows that the APIs are synchronous but might be
 mistakenly marked as async for some reason.  This is a possible workaround
 for issues like https://github.com/konsoletyper/teavm/issues/248

---
 .../teavm/model/util/AsyncMethodFinder.java   | 15 ++++++++--
 .../org/teavm/interop/SuppressSyncErrors.java | 28 +++++++++++++++++++
 2 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 interop/core/src/main/java/org/teavm/interop/SuppressSyncErrors.java

diff --git a/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java b/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java
index 5e1feec2f..fe72b3a69 100644
--- a/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java
+++ b/core/src/main/java/org/teavm/model/util/AsyncMethodFinder.java
@@ -28,6 +28,7 @@ import org.teavm.callgraph.CallGraphNode;
 import org.teavm.callgraph.CallSite;
 import org.teavm.diagnostics.Diagnostics;
 import org.teavm.interop.Async;
+import org.teavm.interop.SuppressSyncErrors;
 import org.teavm.interop.Sync;
 import org.teavm.model.CallLocation;
 import org.teavm.model.ClassReader;
@@ -156,9 +157,17 @@ public class AsyncMethodFinder {
         }
         if (method.getAnnotations().get(Sync.class.getName()) != null
                 || method.getAnnotations().get(InjectedBy.class.getName()) != null) {
-            diagnostics.error(new CallLocation(methodRef), "Method {{m0}} is claimed to be synchronous, "
-                    + "but it is has invocations of asynchronous methods:" + stack.toString(), methodRef);
-            return;
+            if (method.getAnnotations().get(SuppressSyncErrors.class.getName()) == null) {
+                diagnostics.error(new CallLocation(methodRef), "Method {{m0}} is claimed to be "
+                        + "synchronous, but it is has invocations of asynchronous methods:" 
+                        + stack.toString(), methodRef);
+                return;
+            } else {
+                diagnostics.warning(new CallLocation(methodRef), "Error as Warning because "
+                        + " Method {{m0}} has @SuppressSyncErrors annoation. Method {{m0}} "
+                        + "is claimed to be synchronous, but it is has invocations of "
+                        + "asynchronous methods:" + stack.toString(), methodRef);
+            }
         }
         for (CallSite callSite : node.getCallerCallSites()) {
             MethodReference nextMethod = callSite.getCaller().getMethod();
diff --git a/interop/core/src/main/java/org/teavm/interop/SuppressSyncErrors.java b/interop/core/src/main/java/org/teavm/interop/SuppressSyncErrors.java
new file mode 100644
index 000000000..c20bf710a
--- /dev/null
+++ b/interop/core/src/main/java/org/teavm/interop/SuppressSyncErrors.java
@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2016 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.interop;
+
+import java.lang.annotation.*;
+
+/**
+ * 
+ * @author Steve Hannah
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface SuppressSyncErrors {
+}
+