From 8100b6c13d864f2896cf776c150cb0f920e719d7 Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Thu, 28 Jan 2021 18:53:00 +0100
Subject: [PATCH] build: `scope` parameter added to `set_warnings()`

---
 CMakeLists.txt       |  2 +-
 cmake/warnings.cmake | 12 ++++++++----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 00514deb..275065dd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,7 +38,7 @@ add_subdirectory(src)
 
 # set restrictive compilation warnings
 include(warnings)
-set_warnings(mp-units)
+set_warnings(mp-units INTERFACE)
 
 # add usage example
 add_subdirectory(example)
diff --git a/cmake/warnings.cmake b/cmake/warnings.cmake
index 9de6cf6a..e810146b 100644
--- a/cmake/warnings.cmake
+++ b/cmake/warnings.cmake
@@ -25,13 +25,17 @@
 cmake_minimum_required(VERSION 3.2)
 
 # Configure compiler warning level
-function(set_warnings target)
+function(set_warnings target scope)
     option(WARNINGS_AS_ERRORS "Treat compiler warnings as errors" TRUE)
 
     if(NOT TARGET ${target})
         message(FATAL_ERROR "'${target}' is not a CMake target")
     endif()
 
+    if(NOT (scope STREQUAL "PRIVATE" OR scope STREQUAL "PUBLIC" OR scope STREQUAL "INTERFACE"))
+        message(FATAL_ERROR "'${scope}' is not one of (PRIVATE, PUBLIC, INTERFACE)")
+    endif()
+
     set(MSVC_WARNINGS
         /W4 # Baseline reasonable warnings
         /w14062 # enumerator 'identifier' in a switch of enum 'enumeration' is not handled
@@ -101,11 +105,11 @@ function(set_warnings target)
     if(MSVC)
         string(REGEX REPLACE "/W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}" PARENT_SCOPE)
-        target_compile_options(${target} INTERFACE ${MSVC_WARNINGS})
+        target_compile_options(${target} ${scope} ${MSVC_WARNINGS})
     elseif(CMAKE_CXX_COMPILER_ID MATCHES ".*Clang")
-        target_compile_options(${target} INTERFACE ${CLANG_WARNINGS})
+        target_compile_options(${target} ${scope} ${CLANG_WARNINGS})
     elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-        target_compile_options(${target} INTERFACE ${GCC_WARNINGS})
+        target_compile_options(${target} ${scope} ${GCC_WARNINGS})
     else()
         message(AUTHOR_WARNING "No compiler warnings set for '${CMAKE_CXX_COMPILER_ID}' compiler.")
     endif()