From 2209a5abd18be77c6c865c837368b4e459ae7c8e Mon Sep 17 00:00:00 2001
From: Gabriel Ferreira <gabrielcarvfer@gmail.com>
Date: Tue, 13 Feb 2024 21:34:09 +0100
Subject: [PATCH] build: bump minimum GCC version to 9.1 and remove libfs
 compiler workaround

---
 CMakeLists.txt                                |  2 +-
 .../ns3-compiler-workarounds.cmake            | 19 -------------------
 .../custom-modules/ns3-module-macros.cmake    |  4 ----
 3 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6137a0f5d..3802b9695 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,7 +13,7 @@ file(STRINGS VERSION NS3_VER)
 # minimum compiler versions
 set(AppleClang_MinVersion 11.0.0)
 set(Clang_MinVersion 10.0.0)
-set(GNU_MinVersion 9.0.0)
+set(GNU_MinVersion 9.1.0)
 
 # common options
 option(NS3_ASSERT "Enable assert on failure" OFF)
diff --git a/build-support/custom-modules/ns3-compiler-workarounds.cmake b/build-support/custom-modules/ns3-compiler-workarounds.cmake
index 32e37d85a..4386dafd5 100644
--- a/build-support/custom-modules/ns3-compiler-workarounds.cmake
+++ b/build-support/custom-modules/ns3-compiler-workarounds.cmake
@@ -14,22 +14,3 @@
 # Place, Suite 330, Boston, MA  02111-1307 USA
 #
 # Author: Gabriel Ferreira <gabrielcarvfer@gmail.com>
-
-include(CheckCXXSourceCompiles)
-
-# Some compilers (e.g. GCC < 9.1) do not link
-# std::filesystem/std::experimental::filesystem by default. If the sample
-# program can be linked, it means it is indeed linked by default. Otherwise, we
-# link it manually. https://en.cppreference.com/w/cpp/filesystem
-check_cxx_source_compiles(
-  "
-  #include <filesystem>
-
-  int main()
-  {
-    std::string path = \"/\";
-    return !std::filesystem::exists(path);
-  }
-  "
-  FILESYSTEM_LIBRARY_IS_LINKED
-)
diff --git a/build-support/custom-modules/ns3-module-macros.cmake b/build-support/custom-modules/ns3-module-macros.cmake
index e0b3e41e5..a64790840 100644
--- a/build-support/custom-modules/ns3-module-macros.cmake
+++ b/build-support/custom-modules/ns3-module-macros.cmake
@@ -179,10 +179,6 @@ function(build_lib)
       )
     endif()
 
-    if(NOT FILESYSTEM_LIBRARY_IS_LINKED)
-      list(APPEND BLIB_LIBRARIES_TO_LINK -lstdc++fs)
-    endif()
-
     # Enable examples as tests suites
     if(${ENABLE_EXAMPLES} AND ${ENABLE_TESTS})
       if(NOT ${XCODE})