Fix coverage reporting with for comprehensions and add some tests to …

…prove it

compiler/src/dotty/tools/dotc/transform/InstrumentCoverage.scala

@@ -166,14 +166,9 @@ class InstrumentCoverage extends MacroTransform with IdentityDenotTransformer:
         InstrumentedParts.notCovered(tree)
 
     private def tryInstrument(tree: Select)(using Context): InstrumentedParts =
-      val sym = tree.symbol
       val transformed = cpy.Select(tree)(transform(tree.qualifier), tree.name)
-      if canInstrumentParameterless(sym) then
-        // call to a parameterless method
-        val coverageCall = createInvokeCall(tree, tree.sourcePos)
-        InstrumentedParts.singleExpr(coverageCall, transformed)
-      else
-        InstrumentedParts.notCovered(transformed)
+      val coverageCall = createInvokeCall(tree, tree.sourcePos)
+      InstrumentedParts.singleExpr(coverageCall, transformed)
 
     /** Generic tryInstrument */
     private def tryInstrument(tree: Tree)(using Context): InstrumentedParts =

tests/coverage/pos/Escaping.scoverage.check

@@ -42,6 +42,23 @@ covtest.\n
 Class
 covtest.\n.\r\n\f
 \r\n\f
+69
+73
+3
+\\
+Ident
+false
+0
+false
+`\\\\`
+
+2
+Escaping.scala
+covtest.\n
+\r\n\f
+Class
+covtest.\n.\r\n\f
+\r\n\f
 40
 48
 3

tests/coverage/pos/ForComprehension.scala

@@ -0,0 +1,10 @@
+package covtest
+
+def testForComprehension: Unit =
+  for {
+    a <- List(1)
+    b <- List(1)
+    if b > 1
+    c = a + b
+  } yield (a, b, c)
+

tests/coverage/pos/ForComprehension.scoverage.check

@@ -0,0 +1,190 @@
+# Coverage data, format version: 3.0
+# Statement data:
+# - id
+# - source path
+# - package name
+# - class name
+# - class type (Class, Object or Trait)
+# - full class name
+# - method name
+# - start offset
+# - end offset
+# - line number
+# - symbol name
+# - tree name
+# - is branch
+# - invocations count
+# - is ignored
+# - description (can be multi-line)
+# '' sign
+# ------------------------------------------
+0
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+testForComprehension
+52
+138
+3
+flatMap
+Apply
+false
+0
+false
+for {\n    a <- List(1)\n    b <- List(1)\n    if b > 1\n    c = a + b\n  } yield (a, b, c)
+
+1
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+testForComprehension
+67
+74
+4
+apply
+Apply
+false
+0
+false
+List(1)
+
+2
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+testForComprehension
+67
+71
+4
+List
+Ident
+false
+0
+false
+List
+
+3
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+$anonfun
+79
+138
+5
+map
+Apply
+false
+0
+false
+b <- List(1)\n    if b > 1\n    c = a + b\n  } yield (a, b, c)
+
+4
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+$anonfun
+79
+118
+5
+map
+Apply
+false
+0
+false
+b <- List(1)\n    if b > 1\n    c = a + b
+
+5
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+$anonfun
+79
+104
+5
+withFilter
+Apply
+false
+0
+false
+b <- List(1)\n    if b > 1
+
+6
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+$anonfun
+84
+91
+5
+apply
+Apply
+false
+0
+false
+List(1)
+
+7
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+$anonfun
+84
+88
+5
+List
+Ident
+false
+0
+false
+List
+
+8
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+$anonfun
+79
+110
+5
+apply
+Apply
+false
+0
+false
+b <- List(1)\n    if b > 1\n    c
+
+9
+ForComprehension.scala
+covtest
+ForComprehension$package$
+Object
+covtest.ForComprehension$package$
+testForComprehension
+17
+41
+2
+testForComprehension
+DefDef
+false
+0
+false
+def testForComprehension
+

tests/coverage/pos/Lift.scoverage.check

@@ -76,6 +76,23 @@ SomeFunctions
 Class
 covtest.SomeFunctions
 c
+83
+96
+5
+<init>
+Select
+false
+0
+false
+SomeFunctions
+
+4
+Lift.scala
+covtest
+SomeFunctions
+Class
+covtest.SomeFunctions
+c
 75
 80
 5
@@ -86,7 +103,7 @@ false
 false
 def c
 
-4
+5
 Lift.scala
 covtest
 SomeFunctions
@@ -103,7 +120,7 @@ false
 false
 c.f(g())
 
-5
+6
 Lift.scala
 covtest
 SomeFunctions
@@ -120,7 +137,24 @@ false
 false
 c
 
-6
+7
+Lift.scala
+covtest
+SomeFunctions
+Class
+covtest.SomeFunctions
+test
+113
+116
+7
+f
+Select
+false
+0
+false
+c.f
+
+8
 Lift.scala
 covtest
 SomeFunctions
@@ -137,7 +171,24 @@ false
 false
 g()
 
+9
+Lift.scala
+covtest
+SomeFunctions
+Class
+covtest.SomeFunctions
+test
+117
+118
 7
+g
+Select
+false
+0
+false
+g
+
+10
 Lift.scala
 covtest
 SomeFunctions

tests/coverage/run/for_comprehension/test.check

@@ -0,0 +1,4 @@
+1
+2
+1
+2

tests/coverage/run/for_comprehension/test.scala

@@ -0,0 +1,41 @@
+@main
+def Test: Unit = {
+
+  def unreachableFunction(): Seq[Int] = {
+    for {
+      a <- List(1)
+      b <- List(2)
+    } yield {
+      println(a)
+      println(b)
+      a + b
+    }
+  }
+
+  def unreachableFunctionUnlessTrue(flag: Boolean): Option[Int] = {
+    if (flag) {
+      val foo: Seq[Int] = for {
+        a <- List(1)
+        b <- List(2)
+      } yield {
+        println(a)
+        println(b)
+        a + b
+      }
+      foo.headOption
+    } else {
+      None
+    }
+  }
+
+  for {
+    a <- List(1)
+    b <- List(2)
+  } yield  {
+    println(a)
+    println(b)
+    (a, b)
+  }
+
+  unreachableFunctionUnlessTrue(false)
+}