From 93699e59314fca24ad49ab31da5d6d0d3f331944 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=98yvind=20Raddum=20Berg?= <elacin@gmail.com>
Date: Wed, 10 May 2017 18:47:00 +0200
Subject: [PATCH] Add support for configuring the plugin to only emit warnings
 instead of errors

---
 build.sbt                                       |  2 +-
 readme.md                                       |  9 +++++++++
 src/main/scala/acyclic/plugin/Plugin.scala      |  7 ++++++-
 src/main/scala/acyclic/plugin/PluginPhase.scala | 11 +++++++++--
 4 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/build.sbt b/build.sbt
index 3fd0f8e..db0bdc6 100644
--- a/build.sbt
+++ b/build.sbt
@@ -3,7 +3,7 @@ organization  := "com.lihaoyi"
 
 name := "acyclic"
 
-version := "0.1.7"
+version := "0.1.8"
 
 scalaVersion  := "2.11.8"
 
diff --git a/readme.md b/readme.md
index b7f29e8..5b28ab2 100644
--- a/readme.md
+++ b/readme.md
@@ -219,6 +219,15 @@ import acyclic.skipped
 
 to tell the acyclic plugin to ignore them.
 
+Warnings instead of errors
+==========================
+
+If you want the plugin to only emit warnings instead of errors, add `warn` to the plugin's flags.
+
+```scala
+scalacOptions += "-P:acyclic:warn"
+```
+
 Limitations
 ===========
 
diff --git a/src/main/scala/acyclic/plugin/Plugin.scala b/src/main/scala/acyclic/plugin/Plugin.scala
index 257894c..61d6e02 100644
--- a/src/main/scala/acyclic/plugin/Plugin.scala
+++ b/src/main/scala/acyclic/plugin/Plugin.scala
@@ -11,16 +11,21 @@ class TestPlugin(val global: Global,
   val name = "acyclic"
 
   var force = false
+  var fatal = true
+
   // Yeah processOptions is deprecated but keep using it anyway for 2.10.x compatibility
   override def processOptions(options: List[String], error: String => Unit): Unit = {
     if (options.contains("force")) {
       force = true
     }
+    if (options.contains("warn")) {
+      fatal = false
+    }
   }
   val description = "Allows the developer to prohibit inter-file dependencies"
 
 
   val components = List[tools.nsc.plugins.PluginComponent](
-    new PluginPhase(this.global, cycleReporter, force)
+    new PluginPhase(this.global, cycleReporter, force, fatal)
   )
 }
diff --git a/src/main/scala/acyclic/plugin/PluginPhase.scala b/src/main/scala/acyclic/plugin/PluginPhase.scala
index eaee91a..f364a8e 100644
--- a/src/main/scala/acyclic/plugin/PluginPhase.scala
+++ b/src/main/scala/acyclic/plugin/PluginPhase.scala
@@ -16,7 +16,8 @@ import tools.nsc.plugins.PluginComponent
  */
 class PluginPhase(val global: Global,
                   cycleReporter: Seq[(Value, SortedSet[Int])] => Unit,
-                  force: => Boolean)
+                  force: => Boolean,
+                  fatal: => Boolean)
                   extends PluginComponent
                   with GraphAnalysis { t =>
 
@@ -145,7 +146,13 @@ class PluginPhase(val global: Global,
           cycleInfo.map{ case (a, b) => a -> b.map(_.pos.line).to[SortedSet]}
         )
 
-        global.error("Unwanted cyclic dependency")
+        val msg = "Unwanted cyclic dependency"
+        if (fatal) {
+          global.error(msg)
+        } else {
+          global.warning(msg)
+        }
+
         for (Seq((value, locs), (nextValue, _)) <- (cycleInfo :+ cycleInfo.head).sliding(2)){
           global.inform("")
           value match{