Merge pull request #10601 from som-snytt/tweak/nonfatal

Improve performance of Boolean extractors such as `NonFatal`
scala · Dec 19, 2023 · 343b85b · 343b85b
2 parents c80c0ff + 4ee1800
commit 343b85b
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Showing 4 changed files with 36 additions and 2 deletions.
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/PatternMatching.scala b/src/compiler/scala/tools/nsc/transform/patmat/PatternMatching.scala
@@ -66,6 +66,14 @@ trait PatternMatching extends Transform
 
   class MatchTransformer(unit: CompilationUnit) extends TypingTransformer(unit) {
     override def transform(tree: Tree): Tree = tree match {
+      case CaseDef(UnApply(Apply(Select(qual, nme.unapply), Ident(nme.SELECTOR_DUMMY) :: Nil), (bind@Bind(b, Ident(nme.WILDCARD))) :: Nil), guard, body)
+        if guard.isEmpty && qual.symbol == definitions.NonFatalModule =>
+        transform(treeCopy.CaseDef(
+          tree,
+          bind,
+          localTyper.typed(atPos(tree.pos)(Apply(gen.mkAttributedRef(definitions.NonFatal_apply), List(Ident(bind.symbol))))),
+          body))
+
       case Match(sel, cases) =>
         val origTp = tree.tpe
 

diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala
@@ -711,7 +711,9 @@ trait Definitions extends api.StandardDefinitions {
     lazy val SuccessClass = requiredClass[scala.util.Success[_]]
     lazy val FutureClass = requiredClass[scala.concurrent.Future[_]]
     lazy val PromiseClass = requiredClass[scala.concurrent.Promise[_]]
-    lazy val NonFatalClass = requiredClass[scala.util.control.NonFatal.type]
+
+    lazy val NonFatalModule = requiredModule[scala.util.control.NonFatal.type]
+    lazy val NonFatal_apply = getMemberMethod(NonFatalModule, nme.apply)
 
     def unspecializedSymbol(sym: Symbol): Symbol = {
       if (sym hasFlag SPECIALIZED) {

diff --git a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala
@@ -396,7 +396,8 @@ trait JavaUniverseForce { self: runtime.JavaUniverse  =>
     definitions.SuccessClass
     definitions.FutureClass
     definitions.PromiseClass
-    definitions.NonFatalClass
+    definitions.NonFatalModule
+    definitions.NonFatal_apply
     definitions.MacroContextType
     definitions.ProductRootClass
     definitions.Any_$eq$eq

diff --git a/test/files/run/nonfatal.scala b/test/files/run/nonfatal.scala
@@ -0,0 +1,23 @@
+
+//> using options -opt:none
+//
+import scala.tools.partest.BytecodeTest
+import scala.tools.testkit.ASMConverters.instructionsFromMethod
+import org.junit.Assert.assertEquals
+
+object Test extends BytecodeTest {
+  def show(): Unit = {
+    val classNode = loadClassNode("C")
+    val f = getMethod(classNode, "f")
+    val g = getMethod(classNode, "g")
+    assertEquals(instructionsFromMethod(f), instructionsFromMethod(g))
+    //sameBytecode(f, g) // prints
+  }
+}
+
+class C {
+  import scala.util.control.NonFatal
+  def x = 42
+  def f = try x catch { case NonFatal(e) => e.printStackTrace(); -1 }
+  def g = try x catch { case e if NonFatal(e) => e.printStackTrace(); -1 }
+}