Fixes undercompilation on local inheritance

In sbt 0.13 days, we could ignore the relationship between two classes defined in the same `*.scala` source file, because they will be compiled anyway, and the invalidation was done at the source file level. With class-based namehashing, the invalidation is done at the class level, so we can no longer ignore inheritance relationship coming from the same source, but we still have old assumptions scattered around the xsbt-dependency implementation.

This change changes two if expressions that was used to filter out dependency info coming from the same source.

One might wonder why it's necessary to keep the local inheritance info, if two classes involved are compiled together anyways. The answer is transitive dependencies. Using trait-trait-211 as example, `gg.table.ObjectConcatHelpers` was changed, eventually causing `xx.EvaluatorTestSupport` to invalidate. However, because of the missing same-source inheritance, it did not invalidate `xx.EvaluatorSpecification`. This meant that neither `xx.StringLibSpecs` was invalidated, and resulting to a runtime error.

Fixes sbt#417

internal/compiler-bridge/src/main/scala/xsbt/Dependency.scala

@@ -92,16 +92,21 @@ final class Dependency(val global: CallbackGlobal) extends LocateClassFile with
     }
 
     // Define processor reusing `processDependency` definition
-    val memberRef = processDependency(DependencyByMemberRef) _
-    val inheritance = processDependency(DependencyByInheritance) _
-    val localInheritance = processDependency(LocalDependencyByInheritance) _
+    val memberRef = processDependency(DependencyByMemberRef, false) _
+    val inheritance = processDependency(DependencyByInheritance, true) _
+    val localInheritance = processDependency(LocalDependencyByInheritance, true) _
+
+    @deprecated("Use processDependency that takes allowLocal.", "1.1.0")
+    def processDependency(context: DependencyContext)(dep: ClassDependency): Unit =
+      processDependency(context, true)(dep)
 
     /*
      * Handles dependency on given symbol by trying to figure out if represents a term
      * that is coming from either source code (not necessarily compiled in this compilation
      * run) or from class file and calls respective callback method.
      */
-    def processDependency(context: DependencyContext)(dep: ClassDependency): Unit = {
+    def processDependency(context: DependencyContext, allowLocal: Boolean)(
+        dep: ClassDependency): Unit = {
       val fromClassName = classNameAsString(dep.from)
 
       def binaryDependency(file: File, binaryClassName: String) =
@@ -133,11 +138,12 @@ final class Dependency(val global: CallbackGlobal) extends LocateClassFile with
           case None =>
             debuglog(Feedback.noOriginFileForExternalSymbol(dep.to))
         }
-      } else if (onSource.file != sourceFile) {
-        // Dependency is internal -- but from other file / compilation unit
+      } else if (onSource.file != sourceFile || allowLocal) {
+        // We cannot ignore dependencies coming from the same source file because
+        // the dependency info needs to propagate. See source-dependencies/trait-trait-211.
         val onClassName = classNameAsString(dep.to)
         callback.classDependency(onClassName, fromClassName, context)
-      } else () // Comes from the same file, ignore
+      }
     }
   }
 
@@ -227,7 +233,6 @@ final class Dependency(val global: CallbackGlobal) extends LocateClassFile with
       val depClass = enclOrModuleClass(dep)
       val dependency = ClassDependency(fromClass, depClass)
       if (!cache.contains(dependency) &&
-          fromClass.associatedFile != depClass.associatedFile &&
           !depClass.isRefinementClass) {
         process(dependency)
         cache.add(dependency)

internal/zinc-core/src/main/scala/sbt/internal/inc/Relations.scala

@@ -275,6 +275,7 @@ object Relations {
       case o: ClassDependencies => internal == o.internal && external == o.external
       case _                    => false
     }
+    override def toString: String = s"ClassDependencies(internal = $internal, external = $external)"
 
     override def hashCode = (internal, external).hashCode
   }
@@ -662,25 +663,21 @@ private class MRelationsNameHashing(
     (srcProd :: libraryDep :: libraryClassName :: memberRef :: inheritance :: classes :: Nil).hashCode
 
   override def toString = (
-    """
+    s"""
     |Relations (with name hashing enabled):
-    |  products: %s
-    |  library deps: %s
-    |  library class names: %s
-    |  class deps: %s
-    |  ext deps: %s
-    |  class names: %s
-    |  used names: %s
-    |  product class names: %s
-    """.trim.stripMargin.format(
-      List(srcProd,
-           libraryDep,
-           libraryClassName,
-           internalClassDep,
-           externalClassDep,
-           classes,
-           names,
-           productClassName) map relation_s: _*)
+    |  products: ${relation_s(srcProd)}
+    |  library deps: ${relation_s(libraryDep)}
+    |  library class names: ${relation_s(libraryClassName)}
+    |  internalDependencies: ${internalDependencies.dependencies map {
+      case (k, vs) => k + " " + relation_s(vs)
+    }}
+    |  externalDependencies: ${externalDependencies.dependencies map {
+      case (k, vs) => k + " " + relation_s(vs)
+    }}
+    |  class names: ${relation_s(classes)}
+    |  used names: ${relation_s(names)}
+    |  product class names: ${relation_s(productClassName)}
+    """.trim.stripMargin
   )
 
 }

internal/zinc-scripted/src/test/scala/sbt/internal/inc/IncHandler.scala

@@ -156,8 +156,8 @@ final class IncHandler(directory: File, cacheDir: File, scriptedLog: ManagedLogg
         val analysis = p.compile(i)
         p.discoverMainClasses(Some(analysis.apis)) match {
           case Seq(mainClassName) =>
-            val classpath = i.si.allJars :+ p.classesDir
-            val loader = ClasspathUtilities.makeLoader(classpath, i.si, directory)
+            val cp = p.classpath(i)
+            val loader = ClasspathUtilities.makeLoader(cp, i.si, directory)
             val main = p.getMainMethod(mainClassName, loader)
             p.invokeMain(loader, main, params)
           case _ =>
@@ -343,6 +343,10 @@ case class ProjectStructure(
     ()
   }
 
+  def classpath(i: IncInstance): Array[File] = {
+    (i.si.allJars.toList ++ (unmanagedJars :+ classesDir) ++ internalClasspath).toArray
+  }
+
   def compile(i: IncInstance): Analysis = {
     dependsOnRef map { dep =>
       dep.compile(i)
@@ -370,9 +374,8 @@ case class ProjectStructure(
                                optionProgress = None,
                                extra)
 
-    val classpath =
-      (i.si.allJars.toList ++ (unmanagedJars :+ classesDir) ++ internalClasspath).toArray
-    val in = compiler.inputs(classpath,
+    val cp = classpath(i)
+    val in = compiler.inputs(cp,
                              sources.toArray,
                              classesDir,
                              scalacOptions,

zinc/src/sbt-test/source-dependencies/patMat-scope/test

@@ -12,9 +12,7 @@ $ sleep 1000
 $ exists target/classes/foo/SealedUsedInPatMatScope.class
 $ exists target/classes/foo/SealedNameUsedInDefaultScope.class
 
-# Default scopes should not change
-$ newer beforeFirstCompilation target/classes/foo/SealedNameUsedInDefaultScope.class
-# But PatMat and direct usage of child should be recompiled
+# PatMat and direct usage of child should be recompiled
 $ newer target/classes/foo/SealedUsedInPatMatScope.class beforeFirstCompilation
 
 # Change type of Sealed

zinc/src/sbt-test/source-dependencies/sealed/test

@@ -5,5 +5,5 @@ $ copy-file changes/A.scala A.scala
 
 # D.scala needs recompiling because the pattern match in D
 # is no longer exhaustive, which emits a warning
-> checkRecompilations 1 A B C E
-> checkRecompilations 2 D
+> checkRecompilations 1
+> checkRecompilations 2 A B C D E

zinc/src/sbt-test/source-dependencies/trait-trait-211/build.json

@@ -0,0 +1,13 @@
+{
+  "projects": [
+    {
+      "name": "mirtest",
+      "scalaVersion": "2.11.8",
+      "dependsOn": ["gg"]
+    },
+    {
+      "name": "gg",
+      "scalaVersion": "2.11.8"
+    }
+  ]
+}

zinc/src/sbt-test/source-dependencies/trait-trait-211/changes/SliceTransforms1.scala

@@ -0,0 +1,10 @@
+package gg
+package table
+
+trait SliceTransforms extends ObjectConcatHelpers {
+  buildNonemptyObjects(0, 1)
+}
+
+trait ObjectConcatHelpers {
+  def buildNonemptyObjects(a: Int, b: Int): Unit = ()
+}

zinc/src/sbt-test/source-dependencies/trait-trait-211/gg/SliceTransforms.scala

@@ -0,0 +1,10 @@
+package gg
+package table
+
+trait SliceTransforms extends ObjectConcatHelpers {
+  buildNonemptyObjects(0)
+}
+
+trait ObjectConcatHelpers {
+  def buildNonemptyObjects(a: Int): Unit = ()
+}

zinc/src/sbt-test/source-dependencies/trait-trait-211/mirtest/EvaluatorSpecs.scala

@@ -0,0 +1,10 @@
+package xx
+
+import gg.table._
+
+trait EvaluatorSpecification extends EvaluatorTestSupport { self =>
+}
+
+trait EvaluatorTestSupport extends SliceTransforms { outer =>
+  def consumeEval: String = "x"
+}

zinc/src/sbt-test/source-dependencies/trait-trait-211/mirtest/Hello.scala

@@ -0,0 +1,14 @@
+package xx
+
+import gg.table._
+
+object Hello extends App {
+  def testEval: Unit = {
+    val consumer = new StringLibSpecs {}
+    consumer.consumeEval
+  }
+  testEval
+}
+
+trait StringLibSpecs extends EvaluatorSpecification { self =>
+}

zinc/src/sbt-test/source-dependencies/trait-trait-211/mirtest/incOptions.properties

@@ -0,0 +1,2 @@
+apiDebug = true
+relationsDebug = true

zinc/src/sbt-test/source-dependencies/trait-trait-211/test

@@ -0,0 +1,4 @@
+> mirtest/run
+
+$ copy-file changes/SliceTransforms1.scala gg/SliceTransforms.scala
+> mirtest/run