CMake/Modules/WriteCompilerDetectionHeader.cmake
Stephen Kelly bc950169c7 WCDH: Remove noise from generated defines.
The DECL part is redundant, and the language part is not needed. The
source language and context already determines the language, so there
is no need to repeat it in the define name.
2014-06-13 18:50:10 +02:00

528 lines
20 KiB
CMake

#.rst:
# WriteCompilerDetectionHeader
# ----------------------------
#
# This module provides the function write_compiler_detection_header().
#
# The ``WRITE_COMPILER_DETECTION_HEADER`` function can be used to generate
# a file suitable for preprocessor inclusion which contains macros to be
# used in source code::
#
# write_compiler_detection_header(
# FILE <file>
# PREFIX <prefix>
# COMPILERS <compiler> [...]
# FEATURES <feature> [...]
# [VERSION <version>]
# [PROLOG <prolog>]
# [EPILOG <epilog>]
# )
#
# The ``write_compiler_detection_header`` function generates the
# file ``<file>`` with macros which all have the prefix ``<prefix>``.
#
# ``VERSION`` may be used to specify the API version to be generated.
# Future versions of CMake may introduce alternative APIs. A given
# API is selected by any ``<version>`` value greater than or equal
# to the version of CMake that introduced the given API and less
# than the version of CMake that introduced its succeeding API.
# The value of the :variable:`CMAKE_MINIMUM_REQUIRED_VERSION`
# variable is used if no explicit version is specified.
# (As of CMake version |release| there is only one API version.)
#
# ``PROLOG`` may be specified as text content to write at the start of the
# header. ``EPILOG`` may be specified as text content to write at the end
# of the header
#
# At least one ``<compiler>`` and one ``<feature>`` must be listed. Compilers
# which are known to CMake, but not specified are detected and a preprocessor
# ``#error`` is generated for them. A preprocessor macro matching
# ``<PREFIX>_COMPILER_IS_<compiler>`` is generated for each compiler
# known to CMake to contain the value ``0`` or ``1``.
#
# Possible compiler identifiers are documented with the
# :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
# Available features in this version of CMake are listed in the
# :prop_gbl:`CMAKE_C_KNOWN_FEATURES` and
# :prop_gbl:`CMAKE_CXX_KNOWN_FEATURES` global properties.
#
# See the :manual:`cmake-compile-features(7)` manual for information on
# compile features.
#
# Feature Test Macros
# ===================
#
# For each compiler, a preprocessor macro is generated matching
# ``<PREFIX>_COMPILER_IS_<compiler>`` which has the content either ``0``
# or ``1``, depending on the compiler in use. Preprocessor macros for
# compiler version components are generated matching
# ``<PREFIX>_COMPILER_VERSION_MAJOR`` ``<PREFIX>_COMPILER_VERSION_MINOR``
# and ``<PREFIX>_COMPILER_VERSION_PATCH`` containing decimal values
# for the corresponding compiler version components, if defined.
#
# A preprocessor test is generated based on the compiler version
# denoting whether each feature is enabled. A preprocessor macro
# matching ``<PREFIX>_COMPILER_<FEATURE>``, where ``<FEATURE>`` is the
# upper-case ``<feature>`` name, is generated to contain the value
# ``0`` or ``1`` depending on whether the compiler in use supports the
# feature:
#
# .. code-block:: cmake
#
# write_compiler_detection_header(
# FILE climbingstats_compiler_detection.h
# PREFIX ClimbingStats
# COMPILERS GNU Clang MSVC
# FEATURES cxx_variadic_templates
# )
#
# .. code-block:: c++
#
# #if ClimbingStats_COMPILER_CXX_VARIADIC_TEMPLATES
# template<typename... T>
# void someInterface(T t...) { /* ... */ }
# #else
# // Compatibility versions
# template<typename T1>
# void someInterface(T1 t1) { /* ... */ }
# template<typename T1, typename T2>
# void someInterface(T1 t1, T2 t2) { /* ... */ }
# template<typename T1, typename T2, typename T3>
# void someInterface(T1 t1, T2 t2, T3 t3) { /* ... */ }
# #endif
#
# Symbol Macros
# =============
#
# Some additional symbol-defines are created for particular features for
# use as symbols which may be conditionally defined empty:
#
# .. code-block:: c++
#
# class MyClass ClimbingStats_FINAL
# {
# ClimbingStats_CONSTEXPR int someInterface() { return 42; }
# };
#
# The ``ClimbingStats_FINAL`` macro will expand to ``final`` if the
# compiler (and its flags) support the ``cxx_final`` feature, and the
# ``ClimbingStats_CONSTEXPR`` macro will expand to ``constexpr``
# if ``cxx_constexpr`` is supported.
#
# The following features generate corresponding symbol defines:
#
# ========================== =================================== =================
# Feature Define Symbol
# ========================== =================================== =================
# ``c_restrict`` ``<PREFIX>_RESTRICT`` ``restrict``
# ``cxx_constexpr`` ``<PREFIX>_CONSTEXPR`` ``constexpr``
# ``cxx_deleted_functions`` ``<PREFIX>_DELETED_FUNCTION`` ``= delete``
# ``cxx_extern_templates`` ``<PREFIX>_EXTERN_TEMPLATE`` ``extern``
# ``cxx_final`` ``<PREFIX>_FINAL`` ``final``
# ``cxx_noexcept`` ``<PREFIX>_NOEXCEPT`` ``noexcept``
# ``cxx_noexcept`` ``<PREFIX>_NOEXCEPT_EXPR(X)`` ``noexcept(X)``
# ``cxx_override`` ``<PREFIX>_OVERRIDE`` ``override``
# ========================== =================================== =================
#
# Compatibility Implementation Macros
# ===================================
#
# Some features are suitable for wrapping in a macro with a backward
# compatibility implementation if the compiler does not support the feature.
#
# When the ``cxx_static_assert`` feature is not provided by the compiler,
# a compatibility implementation is available via the
# ``<PREFIX>_STATIC_ASSERT(COND)`` and
# ``<PREFIX>_STATIC_ASSERT_MSG(COND, MSG)`` function-like macros. The macros
# expand to ``static_assert`` where that compiler feature is available, and
# to a compatibility implementation otherwise. In the first form, the
# condition is stringified in the message field of ``static_assert``. In
# the second form, the message ``MSG`` is passed to the message field of
# ``static_assert``, or ignored if using the backward compatibility
# implementation.
#
# The ``cxx_attribute_deprecated`` feature provides a macro definition
# ``<PREFIX>_DEPRECATED``, which expands to either the standard
# ``[[deprecated]]`` attribute or a compiler-specific decorator such
# as ``__attribute__((__deprecated__))`` used by GNU compilers.
#
# The ``cxx_alignas`` feature provides a macro definition
# ``<PREFIX>_ALIGNAS`` which expands to either the standard ``alignas``
# decorator or a compiler-specific decorator such as
# ``__attribute__ ((__aligned__))`` used by GNU compilers.
#
# The ``cxx_alignof`` feature provides a macro definition
# ``<PREFIX>_ALIGNOF`` which expands to either the standard ``alignof``
# decorator or a compiler-specific decorator such as ``__alignof__``
# used by GNU compilers.
#
# ============================= ================================ =====================
# Feature Define Symbol
# ============================= ================================ =====================
# ``cxx_alignas`` ``<PREFIX>_ALIGNAS`` ``alignas``
# ``cxx_alignof`` ``<PREFIX>_ALIGNOF`` ``alignof``
# ``cxx_nullptr`` ``<PREFIX>_NULLPTR`` ``nullptr``
# ``cxx_static_assert`` ``<PREFIX>_STATIC_ASSERT`` ``static_assert``
# ``cxx_static_assert`` ``<PREFIX>_STATIC_ASSERT_MSG`` ``static_assert``
# ``cxx_attribute_deprecated`` ``<PREFIX>_DEPRECATED`` ``[[deprecated]]``
# ``cxx_attribute_deprecated`` ``<PREFIX>_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 ``<PREFIX>_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 ${srcs})
# target_compile_definitions(compat_support
# PRIVATE
# CompatSupport_DEPRECATED=
# )
#=============================================================================
# Copyright 2014 Stephen Kelly <steveire@gmail.com>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
include(${CMAKE_CURRENT_LIST_DIR}/CMakeParseArguments.cmake)
include(${CMAKE_CURRENT_LIST_DIR}/CMakeCompilerIdDetection.cmake)
function(_load_compiler_variables CompilerId lang)
include("${CMAKE_ROOT}/Modules/Compiler/${CompilerId}-${lang}-FeatureTests.cmake" OPTIONAL)
set(_cmake_oldestSupported_${CompilerId} ${_cmake_oldestSupported} PARENT_SCOPE)
foreach(feature ${ARGN})
set(_cmake_feature_test_${CompilerId}_${feature} ${_cmake_feature_test_${feature}} PARENT_SCOPE)
endforeach()
include("${CMAKE_ROOT}/Modules/Compiler/${CompilerId}-DetermineCompiler.cmake" OPTIONAL)
set(_compiler_id_version_compute_${CompilerId} ${_compiler_id_version_compute} PARENT_SCOPE)
endfunction()
function(write_compiler_detection_header
file_keyword file_arg
prefix_keyword prefix_arg
)
if (NOT file_keyword STREQUAL FILE)
message(FATAL_ERROR "write_compiler_detection_header: FILE parameter missing.")
endif()
if (NOT prefix_keyword STREQUAL PREFIX)
message(FATAL_ERROR "write_compiler_detection_header: PREFIX parameter missing.")
endif()
set(options)
set(oneValueArgs VERSION EPILOG PROLOG)
set(multiValueArgs COMPILERS FEATURES)
cmake_parse_arguments(_WCD "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
if (NOT _WCD_COMPILERS)
message(FATAL_ERROR "Invalid arguments. write_compiler_detection_header requires at least one compiler.")
endif()
if (NOT _WCD_FEATURES)
message(FATAL_ERROR "Invalid arguments. write_compiler_detection_header requires at least one feature.")
endif()
if(_WCD_UNPARSED_ARGUMENTS)
message(FATAL_ERROR "Unparsed arguments: ${_WCD_UNPARSED_ARGUMENTS}")
endif()
if(NOT _WCD_VERSION)
set(_WCD_VERSION ${CMAKE_MINIMUM_REQUIRED_VERSION})
endif()
set(_min_version 3.1.0) # Version which introduced this function
if (_WCD_VERSION VERSION_LESS _min_version)
set(err "VERSION compatibility for write_compiler_detection_header is set to ${_WCD_VERSION}, which is too low.")
set(err "${err} It must be set to at least ${_min_version}. ")
set(err "${err} Either set the VERSION parameter to the write_compiler_detection_header function, or update")
set(err "${err} your minimum required CMake version with the cmake_minimum_required command.")
message(FATAL_ERROR "${err}")
endif()
set(compilers
GNU
Clang
)
set(_hex_compilers ADSP Borland Embarcadero SunPro)
foreach(_comp ${_WCD_COMPILERS})
list(FIND compilers ${_comp} idx)
if (idx EQUAL -1)
message(FATAL_ERROR "Unsupported compiler ${_comp}.")
endif()
if (NOT _need_hex_conversion)
list(FIND _hex_compilers ${_comp} idx)
if (NOT idx EQUAL -1)
set(_need_hex_conversion TRUE)
endif()
endif()
endforeach()
set(file_content "
// This is a generated file. Do not edit!
#ifndef ${prefix_arg}_COMPILER_DETECTION_H
#define ${prefix_arg}_COMPILER_DETECTION_H
")
if (_WCD_PROLOG)
set(file_content "${file_content}\n${_WCD_PROLOG}\n")
endif()
if (_need_hex_conversion)
set(file_content "${file_content}
#define ${prefix_arg}_DEC(X) (X)
#define ${prefix_arg}_HEX(X) ( \\
((X)>>28 & 0xF) * 10000000 + \\
((X)>>24 & 0xF) * 1000000 + \\
((X)>>20 & 0xF) * 100000 + \\
((X)>>16 & 0xF) * 10000 + \\
((X)>>12 & 0xF) * 1000 + \\
((X)>>8 & 0xF) * 100 + \\
((X)>>4 & 0xF) * 10 + \\
((X) & 0xF) \\
)\n")
endif()
foreach(feature ${_WCD_FEATURES})
if (feature MATCHES "^cxx_")
list(APPEND _langs CXX)
list(APPEND CXX_features ${feature})
elseif (feature MATCHES "^c_")
list(APPEND _langs C)
list(APPEND C_features ${feature})
else()
message(FATAL_ERROR "Unsupported feature ${feature}.")
endif()
endforeach()
list(REMOVE_DUPLICATES _langs)
foreach(_lang ${_langs})
get_property(known_features GLOBAL PROPERTY CMAKE_${_lang}_KNOWN_FEATURES)
foreach(feature ${${_lang}_features})
list(FIND known_features ${feature} idx)
if (idx EQUAL -1)
message(FATAL_ERROR "Unsupported feature ${feature}.")
endif()
endforeach()
if(_lang STREQUAL CXX)
set(file_content "${file_content}\n#ifdef __cplusplus\n")
else()
set(file_content "${file_content}\n#ifndef __cplusplus\n")
endif()
compiler_id_detection(ID_CONTENT ${_lang} PREFIX ${prefix_arg}_
ID_DEFINE
)
set(file_content "${file_content}${ID_CONTENT}\n")
set(pp_if "if")
foreach(compiler ${_WCD_COMPILERS})
_load_compiler_variables(${compiler} ${_lang} ${${_lang}_features})
set(file_content "${file_content}\n# ${pp_if} ${prefix_arg}_COMPILER_IS_${compiler}\n")
set(file_content "${file_content}
# if !(${_cmake_oldestSupported_${compiler}})
# error Unsupported compiler version
# endif\n")
set(PREFIX ${prefix_arg}_)
if (_need_hex_conversion)
set(MACRO_DEC ${prefix_arg}_DEC)
set(MACRO_HEX ${prefix_arg}_HEX)
else()
set(MACRO_DEC)
set(MACRO_HEX)
endif()
string(CONFIGURE "${_compiler_id_version_compute_${compiler}}" VERSION_BLOCK @ONLY)
set(file_content "${file_content}${VERSION_BLOCK}\n")
set(PREFIX)
set(MACRO_DEC)
set(MACRO_HEX)
set(pp_if "elif")
foreach(feature ${${_lang}_features})
string(TOUPPER ${feature} feature_upper)
set(feature_PP "COMPILER_${feature_upper}")
set(_define_item "\n# define ${prefix_arg}_${feature_PP} 0\n")
if (_cmake_feature_test_${compiler}_${feature} STREQUAL "1")
set(_define_item "\n# define ${prefix_arg}_${feature_PP} 1\n")
elseif (_cmake_feature_test_${compiler}_${feature})
set(_define_item "\n# define ${prefix_arg}_${feature_PP} 0\n")
set(_define_item "\n# if ${_cmake_feature_test_${compiler}_${feature}}\n# define ${prefix_arg}_${feature_PP} 1\n# else${_define_item}# endif\n")
endif()
set(file_content "${file_content}${_define_item}")
endforeach()
endforeach()
if(pp_if STREQUAL "elif")
set(file_content "${file_content}
# else
# error Unsupported compiler
# endif\n")
endif()
foreach(feature ${${_lang}_features})
string(TOUPPER ${feature} feature_upper)
set(feature_PP "COMPILER_${feature_upper}")
set(def_name ${prefix_arg}_${feature_PP})
if (feature STREQUAL c_restrict)
set(def_value "${prefix_arg}_RESTRICT")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} restrict
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_constexpr)
set(def_value "${prefix_arg}_CONSTEXPR")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} constexpr
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_final)
set(def_value "${prefix_arg}_FINAL")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} final
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_override)
set(def_value "${prefix_arg}_OVERRIDE")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} override
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_static_assert)
set(def_value "${prefix_arg}_STATIC_ASSERT(X)")
set(def_value_msg "${prefix_arg}_STATIC_ASSERT_MSG(X, MSG)")
set(static_assert_struct "template<bool> struct ${prefix_arg}StaticAssert;\ntemplate<> struct ${prefix_arg}StaticAssert<true>{};\n")
set(def_standard "# define ${def_value} static_assert(X, #X)\n# define ${def_value_msg} static_assert(X, MSG)")
set(def_alternative "${static_assert_struct}# define ${def_value} sizeof(${prefix_arg}StaticAssert<X>)\n# define ${def_value_msg} sizeof(${prefix_arg}StaticAssert<X>)")
set(file_content "${file_content}# if ${def_name}\n${def_standard}\n# else\n${def_alternative}\n# endif\n\n")
endif()
if (feature STREQUAL cxx_alignas)
set(def_value "${prefix_arg}_ALIGNAS(X)")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} alignas(X)
# elif ${prefix_arg}_COMPILER_IS_GNU
# define ${def_value} __attribute__ ((__aligned__(X)))
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_alignof)
set(def_value "${prefix_arg}_ALIGNOF(X)")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} alignof(X)
# elif ${prefix_arg}_COMPILER_IS_GNU
# define ${def_value} __alignof__(X)
# endif
\n")
endif()
if (feature STREQUAL cxx_deleted_functions)
set(def_value "${prefix_arg}_DELETED_FUNCTION")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} = delete
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_extern_templates)
set(def_value "${prefix_arg}_EXTERN_TEMPLATE")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} extern
# else
# define ${def_value}
# endif
\n")
endif()
if (feature STREQUAL cxx_noexcept)
set(def_value "${prefix_arg}_NOEXCEPT")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} noexcept
# define ${def_value}_EXPR(X) noexcept(X)
# else
# define ${def_value}
# define ${def_value}_EXPR(X)
# endif
\n")
endif()
if (feature STREQUAL cxx_nullptr)
set(def_value "${prefix_arg}_NULLPTR")
set(file_content "${file_content}
# if ${def_name}
# define ${def_value} nullptr
# else
# define ${def_value} static_cast<void*>(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 ${def_value}_MSG(MSG)
# endif
# endif
\n")
endif()
endforeach()
set(file_content "${file_content}#endif\n")
endforeach()
if (_WCD_EPILOG)
set(file_content "${file_content}\n${_WCD_EPILOG}\n")
endif()
set(file_content "${file_content}\n#endif")
set(CMAKE_CONFIGURABLE_FILE_CONTENT ${file_content})
configure_file("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in"
"${file_arg}"
@ONLY
)
endfunction()