From babc7d8c16be56a99b5d3e28bbd02edc0576beaa Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Tue, 29 Oct 2024 15:08:35 +0800
Subject: [PATCH] fixes #23545; C compiler error when default initializing an
 object field function (#24375)

fixes #23545

(cherry picked from commit 815bbf0e7312b62de6a8df96349329dbb1740fb9)
---
 compiler/semtypes.nim                   | 17 +++++++++++++++++
 tests/objects/tobject_default_value.nim | 13 +++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim
index e3c6fb1090..757076f850 100644
--- a/compiler/semtypes.nim
+++ b/compiler/semtypes.nim
@@ -257,6 +257,22 @@ proc isRecursiveType(t: PType, cycleDetector: var IntSet): bool =
   else:
     return false
 
+proc annotateClosureConv(n: PNode) =
+  case n.kind
+  of {nkNone..nkNilLit}:
+    discard
+  of nkTupleConstr:
+    if n.typ.kind == tyProc and n.typ.callConv == ccClosure and
+        n[0].typ.kind == tyProc and n[0].typ.callConv != ccClosure:
+      # restores `transf.generateThunk`
+      n[0] = newTreeIT(nkHiddenSubConv, n[0].info, n.typ,
+                       newNodeI(nkEmpty, n[0].info), n[0])
+      n.transitionSonsKind(nkClosure)
+      n.flags.incl nfTransf
+  else:
+    for i in 0..<n.len:
+      annotateClosureConv(n[i])
+
 proc fitDefaultNode(c: PContext, n: PNode): PType =
   inc c.inStaticContext
   let expectedType = if n[^2].kind != nkEmpty: semTypeNode(c, n[^2], nil) else: nil
@@ -272,6 +288,7 @@ proc fitDefaultNode(c: PContext, n: PNode): PType =
         # `changeType` to infer types for constant values
         # that's also the reason why we don't use `semExpr` to check
         # the type since two overlapping error messages might be produced
+    annotateClosureConv(n)
     result = n[^1].typ
   else:
     result = n[^1].typ
diff --git a/tests/objects/tobject_default_value.nim b/tests/objects/tobject_default_value.nim
index 0cd05e4f34..700e8e0a7d 100644
--- a/tests/objects/tobject_default_value.nim
+++ b/tests/objects/tobject_default_value.nim
@@ -776,5 +776,18 @@ template main {.dirty.} =
     var d: limited_int;
     doAssert d == 1
 
+  block: # bug #23545
+    proc evaluate(params: int) =
+        discard
+
+    proc evaluate() =
+        discard
+
+    type SearchInfo = object
+      evaluation: proc() = evaluate
+
+    var a = SearchInfo()
+    a.evaluation()
+
 static: main()
 main()