From 537bd14cff5437d1b39ab7de012264f43670321a Mon Sep 17 00:00:00 2001
From: Gabriel Ferreira <gabrielcarvfer@gmail.com>
Date: Sat, 26 Jul 2025 18:28:37 +0200
Subject: [PATCH] build: Use stacktrace flags by default only in module
 libraries

Previously it was being linked to executables and libraries, which caused symbol redefinitions when building statically.
---
 .../custom-modules/ns3-compiler-workarounds.cmake    | 12 +++++++-----
 build-support/custom-modules/ns3-module-macros.cmake |  4 ++--
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/build-support/custom-modules/ns3-compiler-workarounds.cmake b/build-support/custom-modules/ns3-compiler-workarounds.cmake
index 8bbe15035..6624b787d 100644
--- a/build-support/custom-modules/ns3-compiler-workarounds.cmake
+++ b/build-support/custom-modules/ns3-compiler-workarounds.cmake
@@ -63,18 +63,19 @@ check_cxx_source_compiles(
   "
   STACKTRACE_LIBRARY_ENABLED
 )
+mark_as_advanced(stacktrace_flags)
+set(stacktrace_flags "" CACHE INTERNAL "")
 if(STACKTRACE_LIBRARY_ENABLED)
-  set(stacktrace_flags)
   if(GCC)
     if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "12.0.0")
       # GCC does not support stacktracing
     elseif(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "14.0.0")
-      set(stacktrace_flags -lstdc++_libbacktrace)
+      set(stacktrace_flags -lstdc++_libbacktrace CACHE INTERNAL "")
     else()
-      set(stacktrace_flags -lstdc++exp)
+      set(stacktrace_flags -lstdc++exp CACHE INTERNAL "")
     endif()
   elseif(CLANG)
-    set(stacktrace_flags -lstdc++_libbacktrace)
+    set(stacktrace_flags -lstdc++_libbacktrace CACHE INTERNAL "")
   else()
     # Most likely MSVC, which does not need custom flags for this
   endif()
@@ -96,6 +97,7 @@ if(STACKTRACE_LIBRARY_ENABLED)
 
   if(STACKTRACE_LIBRARY_IS_LINKED)
     add_definitions(-DSTACKTRACE_LIBRARY_IS_LINKED=1)
-    link_libraries(${stacktrace_flags})
+  else()
+    set(stacktrace_flags "" CACHE INTERNAL "")
   endif()
 endif()
diff --git a/build-support/custom-modules/ns3-module-macros.cmake b/build-support/custom-modules/ns3-module-macros.cmake
index 70f2e1ee9..742bc8521 100644
--- a/build-support/custom-modules/ns3-module-macros.cmake
+++ b/build-support/custom-modules/ns3-module-macros.cmake
@@ -288,8 +288,8 @@ endfunction()
 function(build_lib_reexport_third_party_libraries libname libraries_to_link)
   # Separate ns-3 and non-ns-3 libraries to manage their propagation properly
   separate_ns3_from_non_ns3_libs(
-    "${libname}" "${libraries_to_link}" ns_libraries_to_link
-    non_ns_libraries_to_link
+    "${libname}" "${libraries_to_link};${stacktrace_flags}"
+    ns_libraries_to_link non_ns_libraries_to_link
   )
 
   set(ns3-external-libs "${non_ns_libraries_to_link};${ns3-external-libs}"