From 13731926a788ce747720106c9935724c9e8bf75a Mon Sep 17 00:00:00 2001
From: Guillaume Martres <smarter@ubuntu.com>
Date: Thu, 26 Sep 2024 16:14:47 +0200
Subject: [PATCH] Handle suspension due to macro call in late phases

In the added test case this happens in PostTyper, but I've seen it happen in
Mixin too.

Fixes #18517.
---
 compiler/src/dotty/tools/dotc/core/Phases.scala | 14 +++++++++-----
 .../dotty/tools/dotc/transform/Inlining.scala   |  8 +-------
 tests/pos-macros/i18517/Caller.scala            | 17 +++++++++++++++++
 tests/pos-macros/i18517/Macro.scala             |  7 +++++++
 tests/pos-macros/i18517/User.scala              |  6 ++++++
 5 files changed, 40 insertions(+), 12 deletions(-)
 create mode 100644 tests/pos-macros/i18517/Caller.scala
 create mode 100644 tests/pos-macros/i18517/Macro.scala
 create mode 100644 tests/pos-macros/i18517/User.scala

diff --git a/compiler/src/dotty/tools/dotc/core/Phases.scala b/compiler/src/dotty/tools/dotc/core/Phases.scala
index 5dff95fc51fb..85df3f9f2c18 100644
--- a/compiler/src/dotty/tools/dotc/core/Phases.scala
+++ b/compiler/src/dotty/tools/dotc/core/Phases.scala
@@ -378,14 +378,18 @@ object Phases {
               ()
             else
               run
-          catch case ex: Throwable if !ctx.run.enrichedErrorMessage =>
-            println(ctx.run.enrichErrorMessage(s"unhandled exception while running $phaseName on $unit"))
-            throw ex
+            buf += unitCtx.compilationUnit
+          catch
+            case _: CompilationUnit.SuspendException => // this unit will be run again in `Run#compileSuspendedUnits`
+            case ex: Throwable if !ctx.run.enrichedErrorMessage =>
+              println(ctx.run.enrichErrorMessage(s"unhandled exception while running $phaseName on $unit"))
+              throw ex
           finally ctx.run.advanceUnit()
-          buf += unitCtx.compilationUnit
         end if
       end for
-      buf.result()
+      val res = buf.result()
+      ctx.run.nn.checkSuspendedUnits(res)
+      res
     end runOn
 
     /** Convert a compilation unit's tree to a string; can be overridden */
diff --git a/compiler/src/dotty/tools/dotc/transform/Inlining.scala b/compiler/src/dotty/tools/dotc/transform/Inlining.scala
index 335d5a38931a..751636c7d806 100644
--- a/compiler/src/dotty/tools/dotc/transform/Inlining.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Inlining.scala
@@ -36,13 +36,7 @@ class Inlining extends MacroTransform, IdentityDenotTransformer {
 
   override def run(using Context): Unit =
     if ctx.compilationUnit.needsInlining || ctx.compilationUnit.hasMacroAnnotations then
-      try super.run
-      catch case _: CompilationUnit.SuspendException => ()
-
-  override def runOn(units: List[CompilationUnit])(using Context): List[CompilationUnit] =
-    val newUnits = super.runOn(units).filterNot(_.suspended)
-    ctx.run.nn.checkSuspendedUnits(newUnits)
-    newUnits
+      super.run
 
   override def checkPostCondition(tree: Tree)(using Context): Unit =
     tree match {
diff --git a/tests/pos-macros/i18517/Caller.scala b/tests/pos-macros/i18517/Caller.scala
new file mode 100644
index 000000000000..71d965788e22
--- /dev/null
+++ b/tests/pos-macros/i18517/Caller.scala
@@ -0,0 +1,17 @@
+package dummy
+
+trait BG {
+	val   description: { type Structure }
+	type  Structure =  description.Structure
+}
+
+abstract class Caller extends BG {
+	type Foo >: this.type <: this.type
+
+	transparent inline def generate2() =
+		${Macro.impl() }
+
+	final val description = {
+		generate2()
+	}
+}
diff --git a/tests/pos-macros/i18517/Macro.scala b/tests/pos-macros/i18517/Macro.scala
new file mode 100644
index 000000000000..500075f54c47
--- /dev/null
+++ b/tests/pos-macros/i18517/Macro.scala
@@ -0,0 +1,7 @@
+package dummy
+
+import scala.quoted.*
+
+object Macro:
+	def impl()(using quotes:Quotes) : Expr[Any] =
+	  '{ null }
diff --git a/tests/pos-macros/i18517/User.scala b/tests/pos-macros/i18517/User.scala
new file mode 100644
index 000000000000..8216c581937b
--- /dev/null
+++ b/tests/pos-macros/i18517/User.scala
@@ -0,0 +1,6 @@
+package dummy
+
+trait User:
+  final def bar(cell:Any) : Unit =
+    (cell: cell.type) match
+      case c: (Caller & cell.type) => ()