Move reachability skip to reachabilityCheckable

Author: dwijnand

compiler/src/dotty/tools/dotc/Run.scala

@@ -385,10 +385,10 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
     runPhases(allPhases = fusedPhases)(using runCtx)
     cancelAsyncTasty()
 
+    ctx.reporter.finalizeReporting()
     if (!ctx.reporter.hasErrors)
       Rewrites.writeBack()
     suppressions.runFinished(hasErrors = ctx.reporter.hasErrors)
-    ctx.reporter.finalizeReporting()
     while (finalizeActions.nonEmpty && canProgress()) {
       val action = finalizeActions.remove(0)
       action()

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

@@ -46,13 +46,8 @@ class PatternMatcher extends MiniPhase {
         case rt => tree.tpe
       val translated = new Translator(matchType, this).translateMatch(tree)
 
-      // Skip unreachability analysis on inlined code (eg pos/i19157)
-      if !tpd.enclosingInlineds.nonEmpty then
-        // check exhaustivity and unreachability
-        SpaceEngine.checkMatch(tree)
-      else
-        // only check exhaustivity
-        SpaceEngine.checkMatchExhaustivityOnly(tree)
+      // check exhaustivity and unreachability
+      SpaceEngine.checkMatch(tree)
 
       translated.ensureConforms(matchType)
     }

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -922,6 +922,7 @@ object SpaceEngine {
     !sel.tpe.hasAnnotation(defn.UncheckedAnnot)
     && !sel.tpe.widen.isRef(defn.QuotedExprClass)
     && !sel.tpe.widen.isRef(defn.QuotedTypeClass)
+    && tpd.enclosingInlineds.isEmpty // Skip reachability on inlined code (eg i19157/i22212)
 
   def checkReachability(m: Match)(using Context): Unit = trace(i"checkReachability($m)"):
     val selTyp = toUnderlying(m.selector.tpe).dealias
@@ -972,10 +973,6 @@ object SpaceEngine {
   end checkReachability
 
   def checkMatch(m: Match)(using Context): Unit =
-    checkMatchExhaustivityOnly(m)
-    if reachabilityCheckable(m.selector) then checkReachability(m)
-
-  def checkMatchExhaustivityOnly(m: Match)(using Context): Unit =
     if exhaustivityCheckable(m.selector) then checkExhaustivity(m)
-
+    if reachabilityCheckable(m.selector) then checkReachability(m)
 }

tests/neg-macros/i22212.check

@@ -0,0 +1,21 @@
+
+-- [E029] Pattern Match Exhaustivity Warning: tests/warn/i22212/Test_2.scala:3:19 --------------------------------------
+3 |    Macro.makeMatch() // warn: match may not be exhaustive.
+  |    ^^^^^^^^^^^^^^^^^
+  |    match may not be exhaustive.
+  |
+  |    It would fail on pattern case: Baz
+  |---------------------------------------------------------------------------------------------------------------------
+  |Inline stack trace
+  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+  |This location contains code that was inlined from Macro_1.scala:7
+7 |      (_: Foo) match
+  |       ^^^^^^
+  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+  |This location contains code that was inlined from Macro_1.scala:7
+7 |      (_: Foo) match
+  |      ^
+8 |        case Bar => ()
+   ---------------------------------------------------------------------------------------------------------------------
+  |
+  | longer explanation available when compiling with `-explain`

tests/neg-macros/i22212/Test_2.scala

@@ -0,0 +1,3 @@
+sealed trait Foo
+case object Bar extends Foo
+case object Baz extends Foo

tests/warn/i22212.check

@@ -1,9 +1,5 @@
 import scala.quoted._
 
-sealed trait Foo
-case object Bar extends Foo
-case object Baz extends Foo
-
 object Macro {
   inline def makeMatch() = ${makeMatchImpl}
   def makeMatchImpl(using Quotes) = {

tests/warn/i22212/Data_1.scala

@@ -0,0 +1,3 @@
+object Test:
+  def main(args: Array[String]): Unit =
+    Macro.makeMatch() // warn: match may not be exhaustive.