Emit inline errors at expansion site

Author: nicolasstucki

compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala

@@ -33,7 +33,7 @@ trait MessageRendering {
     */
   def outer(pos: SourcePosition, prefix: String)(implicit ctx: Context): List[String] =
     if (pos.outer.exists)
-       i"$prefix| This location is in code that was inlined at ${pos.outer}" ::
+       i"$prefix| This location is in code that was inlined at $pos" ::
        outer(pos.outer, prefix)
     else Nil
 
@@ -149,9 +149,10 @@ trait MessageRendering {
     val posString = posStr(pos, diagnosticLevel, msg)
     if (posString.nonEmpty) sb.append(posString).append(EOL)
     if (pos.exists && pos.source.file.exists) {
-      val (srcBefore, srcAfter, offset) = sourceLines(pos, diagnosticLevel)
-      val marker = columnMarker(pos, offset, diagnosticLevel)
-      val err = errorMsg(pos, msg.msg, offset)
+      val ompos = if (pos.outermost.contains(pos)) pos else pos.outermost
+      val (srcBefore, srcAfter, offset) = sourceLines(ompos, diagnosticLevel)
+      val marker = columnMarker(ompos, offset, diagnosticLevel)
+      val err = errorMsg(ompos, msg.msg, offset)
       sb.append((srcBefore ::: marker :: err :: outer(pos, " " * (offset - 1)) ::: srcAfter).mkString(EOL))
     }
     else sb.append(msg.msg)

tests/neg/inline-error-pos.check

@@ -0,0 +1,9 @@
+
+inline def foo(x: Int): Int =
+  inline x match
+    case 1 => 9
+
+object Foo {
+  val a = foo(1)
+  val b = foo(2) // error
+}

tests/neg/inline-error-pos.scala

@@ -0,0 +1,9 @@
+
+inline def foo(x: Int): Int =
+  inline x match
+    case 1 => 9
+
+object Foo {
+  val a = foo(1)
+  val b = foo(2) // error
+}