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Diffstat (limited to 'Modules/WriteCompilerDetectionHeader.cmake')
| -rw-r--r-- | Modules/WriteCompilerDetectionHeader.cmake | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/Modules/WriteCompilerDetectionHeader.cmake b/Modules/WriteCompilerDetectionHeader.cmake new file mode 100644 index 0000000..fd236c1 --- /dev/null +++ b/Modules/WriteCompilerDetectionHeader.cmake @@ -0,0 +1,401 @@ +#.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_CXX_KNOWN_FEATURES` global property. +# +# Feature Test Macros +# =================== +# +# For each compiler, a preprocessor test of the compiler version is generated +# 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_DECL_CXX_FINAL +# { +# ClimbingStats_DECL_CXX_CONSTEXPR int someInterface() { return 42; } +# }; +# +# The ``ClimbingStats_DECL_CXX_FINAL`` macro will expand to ``final`` if the +# compiler (and its flags) support the ``cxx_final`` feature, and the +# ``ClimbingStats_DECL_CXX_CONSTEXPR`` macro will expand to ``constexpr`` +# if ``cxx_constexpr`` is supported. +# +# The following features generate corresponding symbol defines: +# +# ========================== =================================== ================= +# Feature Define Symbol +# ========================== =================================== ================= +# ``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. +# +# ====================== ================================ =================== +# 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`` +# ====================== ================================ =================== + + +#============================================================================= +# 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() +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() + if (_WCD_VERSION VERSION_LESS 3.1.0) # Version which introduced this function + message(FATAL_ERROR "VERSION parameter too low.") + endif() + + set(compilers + GNU + ) + foreach(_comp ${_WCD_COMPILERS}) + list(FIND compilers ${_comp} idx) + if (idx EQUAL -1) + message(FATAL_ERROR "Unsupported compiler ${_comp}.") + 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() + + foreach(feature ${_WCD_FEATURES}) + if (feature MATCHES "^cxx_") + list(APPEND _langs CXX) + list(APPEND CXX_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") + 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(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 cxx_constexpr) + set(def_value "${prefix_arg}_DECL_${feature_upper}") + 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}_DECL_${feature_upper}") + set(file_content "${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}_DECL_${feature_upper}") + set(file_content "${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 ${def_value} static_cast<void*>(0) +# endif +\n") + endif() + endforeach() + if(_lang STREQUAL CXX) + set(file_content "${file_content}#endif\n") + endif() + + 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() |