cmake: Add compiler diagnostic flags

Author: hebasto

CMakeLists.txt

@@ -417,6 +417,52 @@ include(cmake/introspection.cmake)
 
 include(cmake/ccache.cmake)
 
+add_library(warn_interface INTERFACE)
+target_link_libraries(core_interface INTERFACE warn_interface)
+if(MSVC)
+  try_append_cxx_flags("/W3" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("/wd4018" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("/wd4244" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("/wd4267" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("/wd4715" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("/wd4805" TARGET warn_interface SKIP_LINK)
+  target_compile_definitions(warn_interface INTERFACE
+    _CRT_SECURE_NO_WARNINGS
+    _SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING
+  )
+else()
+  try_append_cxx_flags("-Wall" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wextra" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wgnu" TARGET warn_interface SKIP_LINK)
+  # Some compilers will ignore -Wformat-security without -Wformat, so just combine the two here.
+  try_append_cxx_flags("-Wformat -Wformat-security" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wvla" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wshadow-field" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wthread-safety" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wloop-analysis" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wredundant-decls" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wunused-member-function" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wdate-time" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wconditional-uninitialized" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wduplicated-branches" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wduplicated-cond" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wlogical-op" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Woverloaded-virtual" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wsuggest-override" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wimplicit-fallthrough" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wunreachable-code" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wdocumentation" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wself-assign" TARGET warn_interface SKIP_LINK)
+  try_append_cxx_flags("-Wundef" TARGET warn_interface SKIP_LINK)
+
+  # Some compilers (gcc) ignore unknown -Wno-* options, but warn about all
+  # unknown options if any other warning is produced. Test the -Wfoo case, and
+  # set the -Wno-foo case if it works.
+  try_append_cxx_flags("-Wunused-parameter" TARGET warn_interface SKIP_LINK
+    IF_CHECK_PASSED "-Wno-unused-parameter"
+  )
+endif()
+
 # Don't allow extended (non-ASCII) symbols in identifiers. This is easier for code review.
 try_append_cxx_flags("-fno-extended-identifiers" TARGET core_interface SKIP_LINK)