Coverage: exclude all Erased method calls

Author: TheElectronWill

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

@@ -5,7 +5,6 @@ import java.io.File
 
 import ast.tpd.*
 import collection.mutable
-import core.Decorators.i
 import core.Flags.*
 import core.Contexts.{Context, ctx, inContext}
 import core.DenotTransformers.IdentityDenotTransformer
@@ -18,18 +17,17 @@ import typer.LiftCoverage
 import util.SourcePosition
 import util.Spans.Span
 import localopt.StringInterpolatorOpt
-import scala.util.chaining.*
 
 /** Implements code coverage by inserting calls to scala.runtime.coverage.Invoker
   * ("instruments" the source code).
   * The result can then be consumed by the Scoverage tool.
   */
 class InstrumentCoverage extends MacroTransform with IdentityDenotTransformer:
-  import InstrumentCoverage.{name, description, InstrumentedParts}
+  import InstrumentCoverage.{InstrumentedParts, ExcludeMethodFlags}
 
-  override def phaseName = name
+  override def phaseName = InstrumentCoverage.name
 
-  override def description = description
+  override def description = InstrumentCoverage.description
 
   // Enabled by argument "-coverage-out OUTPUT_DIR"
   override def isEnabled(using ctx: Context) =
@@ -412,7 +410,7 @@ class InstrumentCoverage extends MacroTransform with IdentityDenotTransformer:
     /** Check if an Apply can be instrumented. Prevents this phase from generating incorrect code. */
     private def canInstrumentApply(tree: Apply)(using Context): Boolean =
       val sym = tree.symbol
-      !sym.isOneOf(Synthetic | Artifact)
+      !sym.isOneOf(ExcludeMethodFlags)
       && !isCompilerIntrinsicMethod(sym)
       && (tree.typeOpt match
         case AppliedType(tycon: NamedType, _) =>
@@ -446,7 +444,7 @@ class InstrumentCoverage extends MacroTransform with IdentityDenotTransformer:
       * in post-erasure checking.
       */
     private def canInstrumentParameterless(sym: Symbol)(using Context): Boolean =
-      sym.is(Method, butNot = Synthetic | Artifact)
+      sym.is(Method, butNot = ExcludeMethodFlags)
       && sym.info.isParameterless
       && !isCompilerIntrinsicMethod(sym)
       && !sym.info.typeSymbol.name.isContextFunction // exclude context functions like in canInstrumentApply
@@ -466,6 +464,7 @@ class InstrumentCoverage extends MacroTransform with IdentityDenotTransformer:
 object InstrumentCoverage:
   val name: String = "instrumentCoverage"
   val description: String = "instrument code for coverage checking"
+  val ExcludeMethodFlags: FlagSet = Synthetic | Artifact | Erased
 
   /**
    * An instrumented Tree, in 3 parts.

tests/coverage/run/erased/test.check

@@ -1,3 +1,4 @@
 foo(a)(b)
+foo(a)(b)
 identity(idem)
-foo(a)(idem)
+foo(a)(idem)

tests/coverage/run/erased/test.scala

@@ -1,5 +1,7 @@
 import scala.language.experimental.erasedDefinitions
 
+erased def parameterless: String = "y"
+
 erased def e(x: String): String = "x"
 def foo(erased a: String)(b: String): String =
   println(s"foo(a)($b)")
@@ -11,5 +13,6 @@ def identity(s: String): String =
 
 @main
 def Test: Unit =
+  foo(parameterless)("b")
   foo(e("a"))("b")
   foo(e("a"))(identity("idem"))

tests/coverage/run/erased/test.scoverage.check

@@ -25,15 +25,15 @@ test$package$
 Object
 <empty>.test$package$
 foo
-149
-162
-4
-s
+181
+203
+6
+println
 Apply
 false
 0
 false
-s"foo(a)($b)"
+println(s"foo(a)($b)")
 
 1
 erased/test.scala
@@ -42,15 +42,15 @@ test$package$
 Object
 <empty>.test$package$
 foo
-141
-163
-4
-println
+189
+202
+6
+s
 Apply
 false
 0
 false
-println(s"foo(a)($b)")
+s"foo(a)($b)"
 
 2
 erased/test.scala
@@ -59,9 +59,9 @@ test$package$
 Object
 <empty>.test$package$
 foo
-92
-99
-3
+132
+139
+5
 foo
 DefDef
 false
@@ -76,15 +76,15 @@ test$package$
 Object
 <empty>.test$package$
 identity
-213
-228
-8
-s
+245
+269
+10
+println
 Apply
 false
 0
 false
-s"identity($s)"
+println(s"identity($s)")
 
 4
 erased/test.scala
@@ -93,15 +93,15 @@ test$package$
 Object
 <empty>.test$package$
 identity
-205
-229
-8
-println
+253
+268
+10
+s
 Apply
 false
 0
 false
-println(s"identity($s)")
+s"identity($s)"
 
 5
 erased/test.scala
@@ -110,9 +110,9 @@ test$package$
 Object
 <empty>.test$package$
 identity
-169
-181
-7
+209
+221
+9
 identity
 DefDef
 false
@@ -127,15 +127,15 @@ test$package$
 Object
 <empty>.test$package$
 Test
-264
-270
-13
-e
+300
+323
+15
+foo
 Apply
 false
 0
 false
-e("a")
+foo(parameterless)("b")
 
 7
 erased/test.scala
@@ -144,9 +144,9 @@ test$package$
 Object
 <empty>.test$package$
 Test
-260
-276
-13
+326
+342
+16
 foo
 Apply
 false
@@ -161,15 +161,15 @@ test$package$
 Object
 <empty>.test$package$
 Test
-291
-307
-14
-identity
+345
+374
+17
+foo
 Apply
 false
 0
 false
-identity("idem")
+foo(e("a"))(identity("idem"))
 
 9
 erased/test.scala
@@ -178,15 +178,15 @@ test$package$
 Object
 <empty>.test$package$
 Test
-279
-308
-14
-foo
+357
+373
+17
+identity
 Apply
 false
 0
 false
-foo(e("a"))(identity("idem"))
+identity("idem")
 
 10
 erased/test.scala
@@ -195,9 +195,9 @@ test$package$
 Object
 <empty>.test$package$
 Test
-235
-249
-12
+275
+289
+14
 Test
 DefDef
 false