Print inlining positions in error messages

Error messages now print the inlined positions as well
as the position of the inlined call, recursively.

2 files changed, 14 insertions, 8 deletions

diff --git a/src/dotty/tools/dotc/core/Contexts.scala b/src/dotty/tools/dotc/core/Contexts.scala
index ea0ab95e6..f2a1fe53e 100644
--- a/src/dotty/tools/dotc/core/Contexts.scala
+++ b/src/dotty/tools/dotc/core/Contexts.scala
@@ -370,12 +370,8 @@ object Contexts {
     /** The current source file; will be derived from current
      *  compilation unit.
      */
-    def source: SourceFile = {
-      val file = Inliner.inlinedSource
-      if (file.exists) file
-      else if (compilationUnit == null) NoSource
-      else compilationUnit.source
-    }
+    def source: SourceFile =
+      if (compilationUnit == null) NoSource else compilationUnit.source
 
     /** Does current phase use an erased types interpretation? */
     def erasedTypes: Boolean = phase.erasedTypes
diff --git a/src/dotty/tools/dotc/core/Decorators.scala b/src/dotty/tools/dotc/core/Decorators.scala
index 387e7e466..fc546667d 100644
--- a/src/dotty/tools/dotc/core/Decorators.scala
+++ b/src/dotty/tools/dotc/core/Decorators.scala
@@ -7,6 +7,8 @@ import Contexts._, Names._, Phases._, printing.Texts._, printing.Printer, printi
 import util.Positions.Position, util.SourcePosition
 import collection.mutable.ListBuffer
 import dotty.tools.dotc.transform.TreeTransforms._
+import typer.Inliner
+import ast.tpd.Inlined
 import scala.language.implicitConversions
 import printing.Formatting._
 
@@ -148,8 +150,16 @@ object Decorators {
     }
   }
 
-  implicit def sourcePos(pos: Position)(implicit ctx: Context): SourcePosition =
-    ctx.source.atPos(pos)
+  implicit def sourcePos(pos: Position)(implicit ctx: Context): SourcePosition = {
+    def recur(inlineds: Stream[Inlined], pos: Position): SourcePosition = inlineds match {
+      case inlined #:: rest =>
+        Inliner.sourceFile(inlined).atPos(pos)
+          .withOuter(recur(rest, inlined.call.pos))
+      case empty =>
+        ctx.source.atPos(pos)
+    }
+    recur(Inliner.enclosingInlineds, pos)
+  }
 
   implicit class StringInterpolators(val sc: StringContext) extends AnyVal {