| #.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 (prefix_arg STREQUAL "") |
| message(FATAL_ERROR "A prefix must be specified") |
| endif() |
| string(MAKE_C_IDENTIFIER ${prefix_arg} cleaned_prefix) |
| if (NOT prefix_arg STREQUAL cleaned_prefix) |
| message(FATAL_ERROR "The prefix must be a valid C identifier.") |
| 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 || ${prefix_arg}_COMPILER_IS_Clang |
| # 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 || ${prefix_arg}_COMPILER_IS_Clang |
| # 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 ${prefix_arg}_COMPILER_IS_GNU || ${prefix_arg}_COMPILER_IS_Clang |
| # define ${def_value} __attribute__((__deprecated__)) |
| # define ${def_value}_MSG(MSG) __attribute__((__deprecated__(MSG))) |
| # elif ${prefix_arg}_COMPILER_IS_MSVC |
| # 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() |
