1 files changed, 117 insertions, 0 deletions
diff --git a/cmake/PickyWarningsCXX.cmake b/cmake/PickyWarningsCXX.cmake
new file mode 100644
index 0000000..4699733
--- /dev/null
+++ b/cmake/PickyWarningsCXX.cmake
@@ -0,0 +1,117 @@
+# nghttp2
+#
+# Copyright (c) 2023 nghttp2 contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+# C++
+
+include(CheckCXXCompilerFlag)
+
+if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+
+  # https://clang.llvm.org/docs/DiagnosticsReference.html
+  # https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
+
+  # WPICKY_ENABLE = Options we want to enable as-is.
+  # WPICKY_DETECT = Options we want to test first and enable if available.
+
+  set(WPICKY_ENABLE "-Wall")
+
+  # ----------------------------------
+  # Add new options here, if in doubt:
+  # ----------------------------------
+  set(WPICKY_DETECT
+  )
+
+  # Assume these options always exist with both clang and gcc.
+  # Require clang 3.0 / gcc 2.95 or later.
+  list(APPEND WPICKY_ENABLE
+  )
+
+  # Always enable with clang, version dependent with gcc
+  set(WPICKY_COMMON_OLD
+    -Wformat-security                    # clang  3.0  gcc  4.1
+  )
+
+  set(WPICKY_COMMON
+  )
+
+  if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    list(APPEND WPICKY_ENABLE
+      ${WPICKY_COMMON_OLD}
+    )
+    # Enable based on compiler version
+    if((CMAKE_CXX_COMPILER_ID STREQUAL "Clang"      AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.6) OR
+       (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 6.3))
+      list(APPEND WPICKY_ENABLE
+        ${WPICKY_COMMON}
+      )
+    endif()
+    if((CMAKE_CXX_COMPILER_ID STREQUAL "Clang"      AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.9) OR
+       (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 8.3))
+      list(APPEND WPICKY_ENABLE
+      )
+    endif()
+    if((CMAKE_CXX_COMPILER_ID STREQUAL "Clang"      AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0) OR
+       (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.4))
+      list(APPEND WPICKY_ENABLE
+      )
+    endif()
+    if((CMAKE_CXX_COMPILER_ID STREQUAL "Clang"      AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0) OR
+       (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10.3))
+      list(APPEND WPICKY_ENABLE
+      )
+    endif()
+  else()  # gcc
+    list(APPEND WPICKY_DETECT
+      ${WPICKY_COMMON}
+    )
+    # Enable based on compiler version
+    if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.3)
+      list(APPEND WPICKY_ENABLE
+        ${WPICKY_COMMON_OLD}
+      )
+    endif()
+  endif()
+
+  #
+
+  unset(_wpicky)
+
+  foreach(_CCOPT IN LISTS WPICKY_ENABLE)
+    set(_wpicky "${_wpicky} ${_CCOPT}")
+  endforeach()
+
+  foreach(_CCOPT IN LISTS WPICKY_DETECT)
+    # surprisingly, CHECK_CXX_COMPILER_FLAG needs a new variable to store each new
+    # test result in.
+    string(MAKE_C_IDENTIFIER "OPT${_CCOPT}" _optvarname)
+    # GCC only warns about unknown -Wno- options if there are also other diagnostic messages,
+    # so test for the positive form instead
+    string(REPLACE "-Wno-" "-W" _CCOPT_ON "${_CCOPT}")
+    check_cxx_compiler_flag(${_CCOPT_ON} ${_optvarname})
+    if(${_optvarname})
+      set(_wpicky "${_wpicky} ${_CCOPT}")
+    endif()
+  endforeach()
+
+  set(WARNCXXFLAGS "${WARNCXXFLAGS} ${_wpicky}")
+endif()