From e4340e000fabb4fb87143712cca8efd7992f0d3c Mon Sep 17 00:00:00 2001
From: Jochen Sprickerhof <git@jochen.sprickerhof.de>
Date: Sun, 2 Feb 2020 00:22:36 +0100
Subject: [PATCH] Link against atomic if needed (found on armel)

Gbp-Pq: Name 0002-Link-against-atomic-if-needed-found-on-armel.patch
---
 CMakeLists.txt          | 14 ++++++++++++++
 cmake/pcl_targets.cmake |  4 ++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1e61bfdb..02b690d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,6 +57,20 @@ elseif(MINGW)
   set(CMAKE_COMPILER_IS_MINGW 1)
 endif()
 
+# https://github.com/fish-shell/fish-shell/issues/5865
+include(CheckCXXSourceCompiles)
+CHECK_CXX_SOURCE_COMPILES("
+#include <atomic>
+struct big { int foo[64]; };
+std::atomic<big> x;
+int main() {
+   return x.load().foo[13];
+}"
+LIBATOMIC_NOT_NEEDED)
+IF (NOT LIBATOMIC_NOT_NEEDED)
+    SET(ATOMIC_LIBRARY "atomic")
+ENDIF()
+
 # Create a variable with expected default CXX flags
 # This will be used further down the road to check if the user explicitly provided CXX flags
 if(CMAKE_COMPILER_IS_MSVC)
diff --git a/cmake/pcl_targets.cmake b/cmake/pcl_targets.cmake
index ff79c207..f12a4723 100644
--- a/cmake/pcl_targets.cmake
+++ b/cmake/pcl_targets.cmake
@@ -230,7 +230,7 @@ function(PCL_ADD_LIBRARY _name)
   endif()
 
   if((UNIX AND NOT ANDROID) OR MINGW)
-    target_link_libraries(${_name} m)
+    target_link_libraries(${_name} m ${ATOMIC_LIBRARY})
   endif()
 
   if(MINGW)
@@ -391,7 +391,7 @@ macro(PCL_ADD_TEST _name _exename)
   #target_link_libraries(${_exename} ${GTEST_BOTH_LIBRARIES} ${PCL_ADD_TEST_LINK_WITH})
   target_link_libraries(${_exename} ${PCL_ADD_TEST_LINK_WITH} ${CLANG_LIBRARIES})
 
-  target_link_libraries(${_exename} Threads::Threads)
+  target_link_libraries(${_exename} Threads::Threads ${ATOMIC_LIBRARY})
 
   #Only applies to MSVC
   if(MSVC)
-- 
2.30.2