From ea5582e14f5b14f5e1425ea93344b51233fa35ce Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 14 Aug 2023 11:58:41 +0200
Subject: [PATCH] Handle macro dependencies through class of `this`

Fixes #18393

[Cherry-picked 671f755403b5f575861414e6c9bc82e16034d6d8]
---
 compiler/src/dotty/tools/dotc/inlines/Inliner.scala | 2 ++
 tests/pos-macros/i18393/Inline_2.scala              | 8 ++++++++
 tests/pos-macros/i18393/Macro_1.scala               | 7 +++++++
 tests/pos-macros/i18393/Test_2.scala                | 5 +++++
 4 files changed, 22 insertions(+)
 create mode 100644 tests/pos-macros/i18393/Inline_2.scala
 create mode 100644 tests/pos-macros/i18393/Macro_1.scala
 create mode 100644 tests/pos-macros/i18393/Test_2.scala

diff --git a/compiler/src/dotty/tools/dotc/inlines/Inliner.scala b/compiler/src/dotty/tools/dotc/inlines/Inliner.scala
index 608ac311a410..0d481ee8e0be 100644
--- a/compiler/src/dotty/tools/dotc/inlines/Inliner.scala
+++ b/compiler/src/dotty/tools/dotc/inlines/Inliner.scala
@@ -1067,6 +1067,8 @@ class Inliner(val call: tpd.Tree)(using Context):
         tree match {
           case tree: RefTree if tree.isTerm && level == -1 && tree.symbol.isDefinedInCurrentRun && !tree.symbol.isLocal =>
             foldOver(tree.symbol :: syms, tree)
+          case _: This if level == -1 && tree.symbol.isDefinedInCurrentRun =>
+            tree.symbol :: syms
           case _: TypTree => syms
           case _ => foldOver(syms, tree)
         }
diff --git a/tests/pos-macros/i18393/Inline_2.scala b/tests/pos-macros/i18393/Inline_2.scala
new file mode 100644
index 000000000000..66fc9b9a135a
--- /dev/null
+++ b/tests/pos-macros/i18393/Inline_2.scala
@@ -0,0 +1,8 @@
+package user
+
+import defn.Macro
+
+object Inline extends Macro {
+  inline def callMacro(): Int =
+    ${ this.impl() }
+}
diff --git a/tests/pos-macros/i18393/Macro_1.scala b/tests/pos-macros/i18393/Macro_1.scala
new file mode 100644
index 000000000000..fe99162bdf84
--- /dev/null
+++ b/tests/pos-macros/i18393/Macro_1.scala
@@ -0,0 +1,7 @@
+package defn
+
+import scala.quoted.*
+
+abstract class Macro {
+  def impl()(using Quotes): Expr[Int] = '{1}
+}
diff --git a/tests/pos-macros/i18393/Test_2.scala b/tests/pos-macros/i18393/Test_2.scala
new file mode 100644
index 000000000000..666bf5fd379f
--- /dev/null
+++ b/tests/pos-macros/i18393/Test_2.scala
@@ -0,0 +1,5 @@
+package user
+
+object Test {
+  Inline.callMacro()
+}