From 5a4e4aea6734560b0e1b4206f1475c49faa00c49 Mon Sep 17 00:00:00 2001
From: Ian McInerney <Ian.S.McInerney@ieee.org>
Date: Sat, 25 Apr 2020 00:46:29 +0100
Subject: [PATCH] Enable new warnings

---
 CMakeLists.txt              | 35 +----------------
 CMakeModules/Warnings.cmake | 76 +++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 33 deletions(-)
 create mode 100644 CMakeModules/Warnings.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c81bd8b625..a288395aac 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -240,39 +240,8 @@ if( CMAKE_VERSION VERSION_LESS 3.1 AND ( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_C
 endif()
 
 
-# Warn about missing override specifiers, if supported
-if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
-    include(CheckCXXCompilerFlag)
-
-    CHECK_CXX_COMPILER_FLAG("-Wsuggest-override" COMPILER_SUPPORTS_WSUGGEST_OVERRIDE)
-
-    if(COMPILER_SUPPORTS_WSUGGEST_OVERRIDE)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsuggest-override")
-    endif()
-
-    CHECK_CXX_COMPILER_FLAG("-Wvla" COMPILER_SUPPORTS_WVLA)
-
-    if(COMPILER_SUPPORTS_WVLA)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=vla")
-    endif()
-
-endif()
-
-
-# Warn about shadowed variables (-Wshadow option), if supported
-# Unfortunately, the swig autogenerated files have a lot of shadowed variables
-# and -Wno-shadow does not exist.
-# Adding -Wshadow can be made only for .cpp files
-# and will be added later in CMakeLists.txt
-if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
-    include(CheckCXXCompilerFlag)
-
-    CHECK_CXX_COMPILER_FLAG("-Wshadow" COMPILER_SUPPORTS_WSHADOW)
-
-    if( COMPILER_SUPPORTS_WSHADOW )
-        set(WSHADOW_FLAGS "-Wshadow")
-    endif()
-endif()
+# Setup the compiler warnings
+include( ${CMAKE_MODULE_PATH}/Warnings.cmake )
 
 if( WIN32 )
     # define UNICODE and_UNICODE definition on Windows. KiCad uses unicode.
diff --git a/CMakeModules/Warnings.cmake b/CMakeModules/Warnings.cmake
new file mode 100644
index 0000000000..8586872686
--- /dev/null
+++ b/CMakeModules/Warnings.cmake
@@ -0,0 +1,76 @@
+#
+#  This program source code file is part of KICAD, a free EDA CAD application.
+#
+#  Copyright (C) 2007-2020 Kicad Developers, see AUTHORS.txt for contributors.
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, you may find one here:
+#  http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+#  or you may search the http://www.gnu.org website for the version 2 license,
+#  or you may write to the Free Software Foundation, Inc.,
+#  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+#
+
+# Only configure warnings for Clang and GCC
+if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
+    include( CheckCXXCompilerFlag )
+
+
+    # Warn about missing override specifiers
+    CHECK_CXX_COMPILER_FLAG( "-Wsuggest-override" COMPILER_SUPPORTS_WSUGGEST_OVERRIDE )
+
+    if( COMPILER_SUPPORTS_WSUGGEST_OVERRIDE )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsuggest-override" )
+        message( STATUS "Enabling warning -Wsugest-override" )
+    endif()
+
+
+    CHECK_CXX_COMPILER_FLAG( "-Wvla" COMPILER_SUPPORTS_WVLA )
+
+    if( COMPILER_SUPPORTS_WVLA )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=vla" )
+        message( STATUS "Enabling error for -Wvla" )
+    endif()
+
+
+    # Warn on implicit switch fallthrough
+    CHECK_CXX_COMPILER_FLAG( "-Wimplicit-fallthrough" COMPILER_SUPPORTS_WIMPLICIT_FALLTHROUGH )
+
+    if( COMPILER_SUPPORTS_WIMPLICIT_FALLTHROUGH )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wimplicit-fallthrough" )
+        message( STATUS "Enabling warning -Wimplicit-fallthrough" )
+    endif()
+
+
+    # Error if there is a problem with function returns
+    CHECK_CXX_COMPILER_FLAG( "-Wreturn-type" COMPILER_SUPPORTS_WRETURN_TYPE )
+
+    if( COMPILER_SUPPORTS_WRETURN_TYPE )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=return-type" )
+        message( STATUS "Enabling error for -Wreturn-type" )
+    endif()
+
+
+    # Warn about shadowed variables (-Wshadow option), if supported
+    # Unfortunately, the swig autogenerated files have a lot of shadowed variables
+    # and -Wno-shadow does not exist.
+    # Adding -Wshadow can be made only for .cpp files
+    # and will be added later in CMakeLists.txt
+    CHECK_CXX_COMPILER_FLAG( "-Wshadow" COMPILER_SUPPORTS_WSHADOW )
+
+    if( COMPILER_SUPPORTS_WSHADOW )
+        set( WSHADOW_FLAGS "-Wshadow" )
+        message( STATUS "Enabling warning -Wshadow" )
+    endif()
+
+endif()