diff --git a/Modules/WriteCompilerDetectionHeader.cmake b/Modules/WriteCompilerDetectionHeader.cmake index f80943dbd..6e64cd209 100644 --- a/Modules/WriteCompilerDetectionHeader.cmake +++ b/Modules/WriteCompilerDetectionHeader.cmake @@ -133,16 +133,37 @@ # ``static_assert``, or ignored if using the backward compatibility # implementation. # -# ====================== ================================ =================== -# Feature Define Symbol -# ====================== ================================ =================== -# ``cxx_alignas`` ``_ALIGNAS`` ``alignas`` -# ``cxx_alignof`` ``_ALIGNOF`` ``alignof`` -# ``cxx_nullptr`` ``_NULLPTR`` ``nullptr`` -# ``cxx_static_assert`` ``_STATIC_ASSERT`` ``static_assert`` -# ``cxx_static_assert`` ``_STATIC_ASSERT_MSG`` ``static_assert`` -# ====================== ================================ =================== - +# The ``cxx_attribute_deprecated`` feature provides a macro definition +# ``_DEPRECATED``, which expands to either the standard +# ``[[deprecated]]`` attribute or a compiler-specific decorator such +# as ``__attribute__((__deprecated__))`` used by GNU compilers. +# +# ============================= ================================ ===================== +# Feature Define Symbol +# ============================= ================================ ===================== +# ``cxx_alignas`` ``_ALIGNAS`` ``alignas`` +# ``cxx_alignof`` ``_ALIGNOF`` ``alignof`` +# ``cxx_nullptr`` ``_NULLPTR`` ``nullptr`` +# ``cxx_static_assert`` ``_STATIC_ASSERT`` ``static_assert`` +# ``cxx_static_assert`` ``_STATIC_ASSERT_MSG`` ``static_assert`` +# ``cxx_attribute_deprecated`` ``_DEPRECATED`` ``[[deprecated]]`` +# ``cxx_attribute_deprecated`` ``_DEPRECATED_MSG`` ``[[deprecated]]`` +# ============================= ================================ ===================== +# +# A use-case which arises with such deprecation macros is the deprecation +# of an entire library. In that case, all public API in the library may +# be decorated with the ``_DEPRECATED`` macro. This results in +# very noisy build output when building the library itself, so the macro +# may be may be defined to empty in that case when building the deprecated +# library: +# +# .. code-block:: cmake +# +# add_library(compat_support ${srcs}) +# target_compile_definitions(compat_support +# PRIVATE +# CompatSupport_DEPRECATED= +# ) #============================================================================= # Copyright 2014 Stephen Kelly @@ -400,6 +421,27 @@ function(write_compiler_detection_header # else # define ${def_value} static_cast(0) # endif +\n") + endif() + if (feature STREQUAL cxx_attribute_deprecated) + set(def_name ${prefix_arg}_${feature_PP}) + set(def_value "${prefix_arg}_DEPRECATED") + set(file_content "${file_content} +# ifndef ${def_value} +# if ${def_name} +# define ${def_value} [[deprecated]] +# define ${def_value}_MSG(MSG) [[deprecated(MSG)]] +# elif defined(__GNUC__) || defined(__clang__) +# define ${def_value} __attribute__((__deprecated__)) +# define ${def_value}_MSG(MSG) __attribute__((__deprecated__(MSG))) +# elif defined(_MSC_VER) +# define ${def_value} __declspec(deprecated) +# define ${def_value}_MSG(MSG) __declspec(deprecated(MSG)) +# else +# define ${def_value} +# define ${def_value}_MSG(MSG) +# endif +# endif \n") endif() endforeach()