From ea3835e4db798913cc20911ca2c4521e0228e3d5 Mon Sep 17 00:00:00 2001
From: aherlihy <herlihyap@gmail.com>
Date: Fri, 2 Feb 2024 17:28:49 +0100
Subject: [PATCH] Fix purity check for val inside of object

Fixes #17317
---
 compiler/src/dotty/tools/dotc/ast/TreeInfo.scala |  3 ++-
 tests/run/i17317-b.check                         |  1 +
 tests/run/i17317-b.scala                         | 12 ++++++++++++
 tests/run/i17317.check                           |  1 +
 tests/run/i17317.scala                           | 12 ++++++++++++
 5 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 tests/run/i17317-b.check
 create mode 100644 tests/run/i17317-b.scala
 create mode 100644 tests/run/i17317.check
 create mode 100644 tests/run/i17317.scala

diff --git a/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala b/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala
index 5ded0e1262e4..28d3ef6daaef 100644
--- a/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala
+++ b/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala
@@ -578,8 +578,9 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
       sym.owner.isPrimitiveValueClass
       || sym.owner == defn.StringClass
       || defn.pureMethods.contains(sym)
+
     tree.tpe.isInstanceOf[ConstantType] && tree.symbol != NoSymbol && isKnownPureOp(tree.symbol) // A constant expression with pure arguments is pure.
-    || fn.symbol.isStableMember && !fn.symbol.is(Lazy)  // constructors of no-inits classes are stable
+    || fn.symbol.isStableMember && fn.symbol.isConstructor // constructors of no-inits classes are stable
 
   /** The purity level of this reference.
    *  @return
diff --git a/tests/run/i17317-b.check b/tests/run/i17317-b.check
new file mode 100644
index 000000000000..3b18e512dba7
--- /dev/null
+++ b/tests/run/i17317-b.check
@@ -0,0 +1 @@
+hello world
diff --git a/tests/run/i17317-b.scala b/tests/run/i17317-b.scala
new file mode 100644
index 000000000000..b1606da6df20
--- /dev/null
+++ b/tests/run/i17317-b.scala
@@ -0,0 +1,12 @@
+object foo {
+  object HelloGen {
+    println("hello world")
+  }
+  val Hello = HelloGen
+}
+
+import foo.Hello
+
+object Test {
+  def main(args: Array[String]): Unit = Hello: Unit
+}
diff --git a/tests/run/i17317.check b/tests/run/i17317.check
new file mode 100644
index 000000000000..3b18e512dba7
--- /dev/null
+++ b/tests/run/i17317.check
@@ -0,0 +1 @@
+hello world
diff --git a/tests/run/i17317.scala b/tests/run/i17317.scala
new file mode 100644
index 000000000000..41ea627c20b9
--- /dev/null
+++ b/tests/run/i17317.scala
@@ -0,0 +1,12 @@
+package object foo {
+  object HelloGen {
+    println("hello world")
+  }
+  val Hello = HelloGen
+}
+
+import foo.Hello
+
+object Test {
+  def main(args: Array[String]): Unit = Hello: Unit
+}