From 872a1198446ecae9a4d34a3e35fb282ab5f63b76 Mon Sep 17 00:00:00 2001
From: Steve Lhomme <slhomme@matroska.org>
Date: Sat, 2 May 2026 09:28:08 +0200
Subject: [PATCH] CMake: check actually needed system headers are used

In dev mode. So CI builds must pass with this mode on.

LIBCPP_REMOVE_TRANSITIVE_INCLUDES is a libc++ thing.
---
 CMakeLists.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0bc28097..eb574bb2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,6 +65,7 @@ endif()
 if(DEV_MODE)
   message(STATUS "Using developer mode for ${CMAKE_CXX_COMPILER_ID}")
   set(CMAKE_CXX_EXTENSIONS OFF)
+  add_definitions("-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES")
   add_cxx_flag_if_supported(-Wno-error=unused-command-line-argument
                             -Wall -Wextra -Wpedantic -Wfatal-errors -fstack-protector-strong
                             -Wcast-align