added tests about source positions during runtime error reporting

shared/src/test/scala/cpstest/stacktraceReporting/SourcePos.scala

@@ -0,0 +1,20 @@
+package cpstest.stacktraceReporting
+
+import scala.quoted._
+
+case class SourcePos(file: String, line: Int)
+
+object SourcePos {
+
+  inline def current: SourcePos =
+    ${ currentImpl }
+
+  def currentImpl(using Quotes): Expr[SourcePos] = {
+    import quotes.reflect._
+    val pos = Position.ofMacroExpansion
+    val file = pos.sourceFile.name
+    val line = pos.startLine + 1 // 1-based
+    '{ SourcePos(${Expr(file)}, ${Expr(line)}) }
+  }
+
+}

shared/src/test/scala/cpstest/stacktraceReporting/TestBasicStacktraceReporting.scala

@@ -0,0 +1,31 @@
+package cpstest.stacktraceReporting
+
+import scala.util.*
+import cps.*
+import org.junit.Test
+
+class TestBasicStacktraceReporting {
+
+
+  @Test
+  def basicStackTrace() = {
+    val startPos = SourcePos.current
+    val c = async[ComputationBound]{
+      val x = await(T1.cbi(1))
+      val y = await(T1.cbi(2))
+      throw new RuntimeException("test")
+      x+y
+    }
+    val endPos = SourcePos.current
+
+    val r = c.run()
+    assert(r.isFailure)
+    r match
+      case  Failure(ex) =>
+        //ex.printStackTrace()
+        //println(s"startPos = ${startPos}")
+        assert(ex.getStackTrace().exists(_.getLineNumber() == startPos.line + 4))
+  }
+
+
+}