Keep line numbers when inlining from the same compilation unit

So far, line numbers were kept only when inlining from the same class.
We can also keep them when inlining from a different class defined in
the same compilation unit.

Longer-term we should support JSR-45, see SI-7518 and scala-dev#3.

2 files changed, 49 insertions, 1 deletions

diff --git a/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala b/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala
index 9b538573dc..9173a1d189 100644
--- a/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala
+++ b/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala
@@ -1526,4 +1526,52 @@ class InlinerTest extends BytecodeTesting {
     val c :: _ = compileClassesSeparately(codes, extraArgs = compilerArgs)
     assertInvoke(getMethod(c, "t"), "p1/Implicits$RichFunction1$", "toRx$extension")
   }
+
+  @Test
+  def keepLineNumbersPerCompilationUnit(): Unit = {
+    val code1 =
+      """class A {
+        |  def fx(): Unit = ()
+        |  @inline final def ma = {
+        |    fx()
+        |    1
+        |  }
+        |}
+      """.stripMargin
+    val code2 =
+      """class B extends A {
+        |  @inline final def mb = {
+        |    fx()
+        |    1
+        |  }
+        |}
+        |class C extends B {
+        |  @inline final def mc = {
+        |    fx()
+        |    1
+        |  }
+        |  def t1 = ma // no lines, not the same source file
+        |  def t2 = mb // lines
+        |  def t3 = mc // lines
+        |}
+      """.stripMargin
+    notPerRun.foreach(_.clear())
+    val run = compiler.newRun
+    run.compileSources(List(makeSourceFile(code1, "A.scala"), makeSourceFile(code2, "B.scala")))
+    val List(_, _, c) = readAsmClasses(getGeneratedClassfiles(global.settings.outputDirs.getSingleOutput.get))
+    def is(name: String) = getMethod(c, name).instructions.filterNot(_.isInstanceOf[FrameEntry])
+
+    assertSameCode(is("t1"), List(
+      Label(0), LineNumber(12, Label(0)),
+      VarOp(ALOAD, 0), Invoke(INVOKEVIRTUAL, "A", "fx", "()V", false),
+      Op(ICONST_1), Op(IRETURN), Label(6)))
+
+    assertSameCode(is("t2"), List(
+      Label(0), LineNumber(3, Label(0)), VarOp(ALOAD, 0), Invoke(INVOKEVIRTUAL, "B", "fx", "()V", false),
+      Label(4), LineNumber(4, Label(4)), Op(ICONST_1), Op(IRETURN), Label(8)))
+
+    assertSameCode(is("t3"), List(
+      Label(0), LineNumber(9, Label(0)), VarOp(ALOAD, 0), Invoke(INVOKEVIRTUAL, "C", "fx", "()V", false),
+      Label(4), LineNumber(10, Label(4)), Op(ICONST_1), Op(IRETURN), Label(8)))
+  }
 }
diff --git a/test/junit/scala/tools/testing/BytecodeTesting.scala b/test/junit/scala/tools/testing/BytecodeTesting.scala
index 1a0c1e210a..4ddb6580df 100644
--- a/test/junit/scala/tools/testing/BytecodeTesting.scala
+++ b/test/junit/scala/tools/testing/BytecodeTesting.scala
@@ -29,7 +29,7 @@ class Compiler(val global: Global) {
     global.settings.outputDirs.setSingleOutput(new VirtualDirectory("(memory)", None))
   }
 
-  private def newRun: global.Run = {
+  def newRun: global.Run = {
     global.reporter.reset()
     resetOutput()
     new global.Run()