From b4727e18785441108dbe91e815bde85f300bb31a Mon Sep 17 00:00:00 2001
From: Francesco Biscani <bluescarni@gmail.com>
Date: Sat, 28 Sep 2024 16:15:33 +0200
Subject: [PATCH] Enable the -fno-assume-unique-vtables flag is possible on
 clang, in order to work around likely buggy compiler optimisation.

---
 cmake/yacma/YACMACompilerLinkerSettings.cmake | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/cmake/yacma/YACMACompilerLinkerSettings.cmake b/cmake/yacma/YACMACompilerLinkerSettings.cmake
index 3d9cd9dab..e56321846 100644
--- a/cmake/yacma/YACMACompilerLinkerSettings.cmake
+++ b/cmake/yacma/YACMACompilerLinkerSettings.cmake
@@ -125,6 +125,18 @@ if(NOT _YACMACompilerLinkerSettingsRun)
         _YACMA_CHECK_ENABLE_DEBUG_CXX_FLAG(-Warray-bounds-pointer-arithmetic)
         # New warnings in clang 14.
         _YACMA_CHECK_ENABLE_DEBUG_CXX_FLAG(-Warray-parameter)
+        # NOTE: clang 17 enables by default a new compiler flag called "-fassume-unique-vtables":
+        #
+        # https://releases.llvm.org/17.0.1/tools/clang/docs/ReleaseNotes.html#c-language-changes
+        #
+        # This flag however seems to be buggy:
+        #
+        # https://github.com/llvm/llvm-project/issues/71196
+        #
+        # On our part, in several projects we are experiencing Boost.serialization failures when
+        # (de)serialising derived objects through pointers to bases. Thus, we forcibly disable
+        # this new flag.
+        _YACMA_CHECK_ENABLE_CXX_FLAG(-fno-assume-unique-vtables)
     endif()
 
     # Common configuration for GCC, clang and Intel.