buildroot/package/log4cxx/0002-boost-fallback-only-check-for-boost-if-really-needed.patch

From 24e7adc8d67b3c8f7d275b4f9a7e70a61b73fcd4 Mon Sep 17 00:00:00 2001
From: Peter Seiderer <ps.report@gmx.net>
Date: Fri, 28 Jan 2022 13:11:01 +0100
Subject: [PATCH] boost-fallback: only check for boost if really needed

- only check for boost if really needed (in case of legacy c++ standard < c++17)

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
---
 src/cmake/boost-fallback/boost-fallback.cmake | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/cmake/boost-fallback/boost-fallback.cmake b/src/cmake/boost-fallback/boost-fallback.cmake
index 8285b0b9..0ecf8c6c 100644
--- a/src/cmake/boost-fallback/boost-fallback.cmake
+++ b/src/cmake/boost-fallback/boost-fallback.cmake
@@ -55,6 +55,8 @@ try_compile(STD_SHARED_PTR_FOUND "${CMAKE_BINARY_DIR}/boost-fallback-compile-tes
 try_compile(STD_ATOMIC_FOUND "${CMAKE_BINARY_DIR}/boost-fallback-compile-tests"
     "${CMAKE_CURRENT_LIST_DIR}/test-stdatomic.cpp")
 
+# search for boost only in case needed for legacy c++ standard < c++17
+if(NOT ${STD_THREAD_FOUND} OR NOT ${STD_MUTEX_FOUND} OR NOT ${STD_SHARED_MUTEX_FOUND} OR NOT ${STD_SHARED_PTR_FOUND} OR NOT ${STD_ATOMIC_FOUND})
 find_package(Boost COMPONENTS thread)
 if( ${Boost_FOUND} )
     try_compile(Boost_SHARED_PTR_FOUND "${CMAKE_BINARY_DIR}/boost-fallback-compile-tests"
@@ -67,6 +69,7 @@ if( ${Boost_FOUND} )
     try_compile(Boost_ATOMIC_FOUND "${CMAKE_BINARY_DIR}/boost-fallback-compile-tests"
         "${CMAKE_CURRENT_LIST_DIR}/test-boostatomic.cpp")
 endif( ${Boost_FOUND} )
+endif()
 
 # Link the target with the appropriate boost libraries(if required)
 function(boostfallback_link target)
-- 
2.34.1