From 14239c9948ff9181620c90e282af06261d389478 Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Mon, 23 Sep 2024 18:05:04 +0300
Subject: [PATCH] don't trust completeStruct for typeinfo gen of imported C++
 types

fixes #24159, refs #23761
---
 compiler/ccgtypes.nim             |  5 ++++-
 tests/ccgbugs/tatomictypeinfo.nim | 14 ++++++++++++++
 tests/ccgbugs/tcgbug.nim          |  1 +
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 tests/ccgbugs/tatomictypeinfo.nim

diff --git a/compiler/ccgtypes.nim b/compiler/ccgtypes.nim
index 5c3e82346d25..93b8b144ec50 100644
--- a/compiler/ccgtypes.nim
+++ b/compiler/ccgtypes.nim
@@ -1474,7 +1474,10 @@ proc genObjectInfo(m: BModule; typ, origType: PType, name: Rope; info: TLineInfo
                       typeToString(typ))
   genTypeInfoAux(m, typ, origType, name, info)
   var tmp = getNimNode(m)
-  if (not isImportedType(typ)) or tfCompleteStruct in typ.flags:
+  if (not isImportedType(typ)) or
+      # don't trust C++ imported fields even if completeStruct to
+      # workaround C++ atomic implementation
+      (tfCompleteStruct in typ.flags and not isImportedCppType(typ)):
     genObjectFields(m, typ, origType, typ.n, tmp, info)
   m.s[cfsTypeInit3].addf("$1.node = &$2;$n", [tiNameForHcr(m, name), tmp])
   var t = typ.baseClass
diff --git a/tests/ccgbugs/tatomictypeinfo.nim b/tests/ccgbugs/tatomictypeinfo.nim
new file mode 100644
index 000000000000..51d34e1f3bec
--- /dev/null
+++ b/tests/ccgbugs/tatomictypeinfo.nim
@@ -0,0 +1,14 @@
+discard """
+  matrix: "--mm:refc; --mm:orc"
+  targets: "c cpp"
+"""
+
+# issue #24159 
+
+import std/atomics
+
+type N = object
+  u: ptr Atomic[int]
+proc w(args: N) = discard
+var e: Thread[N]
+createThread(e, w, default(N))
diff --git a/tests/ccgbugs/tcgbug.nim b/tests/ccgbugs/tcgbug.nim
index 2eddc6fddc23..946aa794d377 100644
--- a/tests/ccgbugs/tcgbug.nim
+++ b/tests/ccgbugs/tcgbug.nim
@@ -4,6 +4,7 @@ success
 M1 M2
 ok
 '''
+targets: "c cpp"
 matrix: "--mm:refc;--mm:orc"
 """