WL#16601: -Werror builds

Author: rsomla1

CMakeLists.txt

@@ -271,31 +271,70 @@ endif()
 # TODO: Fix these warnings.
 #
 
+# TODO: Also cover linker warnings
+
+add_config_option(WERROR BOOL ADVANCED DEFAULT OFF
+  "Turn compile warnings into errors"
+)
+
+#
+# Note: If WERROR is enabled we change its value to be the actual compiler
+# option to be used on the current platform. That is used for easier
+# propagation to external builds.
+#
+# Note: In more recent cmake there is CMAKE_COMPILE_WARNING_AS_ERROR variable
+# but at the moment we can't ensure using that recent cmake.
+#
+
+if(WERROR)
+  set(WERROR -Werror)
+endif()
+
 if(MSVC)
 
   add_definitions(-D_CRT_SECURE_NO_WARNINGS -D_SCL_SECURE_NO_WARNINGS)
 
   if(CXX_FRONTEND_MSVC)
+
+    if(WERROR)
+      set(WERROR /WX)  # MSVC equivalent of -Werror
+    endif()
+
     # Disable MSVC unreachable code warnings unless requested.
     add_compile_options(/wd4702)
 
     # Disable MSVC warning C4297 as it seems to be buggy.
     # Seehttps://connect.microsoft.com/VisualStudio/feedback/details/897611/incorrect-warning-of-c4297-for-destructor-with-try-catch-statement
 
     add_compile_options(/wd4297)
+
   endif()
 
-endif()
+elseif(SUNPRO)
 
+  # Note: For simplicity we do not handle WERROR on SunOS
 
-if(SUNPRO)
+  set(WERROR)
 
   add_compile_options(
     -errtags=yes -erroff=hidevf,wvarhidemem
   )
 
 endif()
 
+if(NOT WERROR)
+  # clear if WERROR was set to something like OFF or FALSE
+  # message(STATUS "WERROR: cleared")
+  unset(WERROR CACHE)
+else()
+  # overwrite cache entry with changed value
+  set(WERROR "${WERROR}" CACHE INTERNAL "WERROR flags" FORCE)
+endif()
+
+# message(STATUS "WERROR: ${WERROR}")
+add_compile_options(${WERROR})
+
+
 if (CMAKE_COMPILER_IS_GNUCC AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 12.0)
   # Silence a warning produced by a regression in GCC 12.0 and newer
   # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106199

cdk/cmake/dependency.cmake

@@ -60,6 +60,7 @@ set(EXT_FWD
   CMAKE_SYSTEM_PROCESSOR
   CMAKE_C_COMPILER CMAKE_CXX_COMPILER
   MSVC
+  WERROR
 )
 
 set(EXT_DIR ${CMAKE_CURRENT_LIST_DIR}/ext CACHE INTERNAL "external project utils location")
@@ -129,7 +130,7 @@ function(add_ext NAME HEADER)
     "${EXT_LIB} library name"
   )
 
-  
+
   #show_config_options()
 
   # Handle non-path value of WITH_X option

cdk/extra/lz4/CMakeLists.txt

@@ -34,6 +34,10 @@ include(platform)
 
 enable_pic()
 
+if(WERROR)
+  add_compile_options(${WERROR})
+endif()
+
 add_library(lz4 STATIC
     lib/lz4.c
     lib/lz4frame.c

cdk/extra/protobuf/CMakeLists.txt

@@ -73,6 +73,10 @@ SET(PROTO_SRC_DIR  "${PROJECT_SOURCE_DIR}/protobuf-3.19.6")
 enable_pic()
 enable_cxx17()
 
+if(WERROR)
+  add_compile_options(${WERROR})
+endif()
+
 # -O3 using GCC on SPARC leds to segfault on protoc
 if(SPARC AND GCC)
   foreach(LANG C CXX)

cdk/extra/zlib/CMakeLists.txt

@@ -9,6 +9,9 @@ set(VERSION "1.3.1")
 project(zlib VERSION ${VERSION} LANGUAGES C)
 
 option(ZLIB_BUILD_EXAMPLES "Enable Zlib Examples" ON)
+if(WERROR)
+  add_compile_options(${WERROR})
+endif()
 
 IF(DISABLE_THESE_LINES)
 set(INSTALL_BIN_DIR "${CMAKE_INSTALL_PREFIX}/bin" CACHE PATH "Installation directory for executables")

cdk/extra/zstd/CMakeLists.txt

@@ -15,6 +15,10 @@ include(platform)
 
 enable_pic()
 
+if(WERROR)
+  add_compile_options(${WERROR})
+endif()
+
 
 SET(ZSTD_LIB_DIR
   "${PROJECT_SOURCE_DIR}/lib")