mirror/CMake
1
0
Fork 0
mirror of https://github.com/Kitware/CMake.git synced 2026-01-01 11:22:21 -06:00
Code Issues Packages Projects Releases Wiki Activity

WCDH: optionally omit error code for unknown compilers or compiler versions

Browse Source 
This allows one to generate a header that will basically always work. In case
an unknown compiler or compiler version is encountered it simply falls back to
the unsupported case.
This commit is contained in:
Rolf Eike Beer
2017-01-25 20:32:59 +01:00
parent 0de9c39850
commit c8703e9d7b
3 changed files with 61 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
Help/release/dev/WCDH_allow_unsupported.rst Normal file
View File

@@ -0,0 +1,8 @@
WCDH_allow_unsupported
----------------------
* The :module:`WriteCompilerDetectionHeader` module gained the
``ALLOW_UNKNOWN_COMPILERS`` and ``ALLOW_UNKNOWN_COMPILER_VERSIONS`` options
that allow creation of headers that will work also with unknown or old
compilers by simply assuming they do not support any of the requested
features.

34
Modules/WriteCompilerDetectionHeader.cmake
View File

@@ -20,6 +20,8 @@
# [VERSION <version>]
# [PROLOG <prolog>]
# [EPILOG <epilog>]
# [ALLOW_UNKNOWN_COMPILERS]
# [ALLOW_UNKNOWN_COMPILER_VERSIONS]
# )
#
# The ``write_compiler_detection_header`` function generates the
@@ -81,6 +83,11 @@
# See the :manual:`cmake-compile-features(7)` manual for information on
# compile features.
#
# ``ALLOW_UNKNOWN_COMPILERS`` and ``ALLOW_UNKNOWN_COMPILER_VERSIONS`` cause
# the module to generate conditions that treat unknown compilers as simply
# lacking all features. Without these options the default behavior is to
# generate a ``#error`` for unknown compilers.
#
# Feature Test Macros
# ===================
#
@@ -236,7 +243,7 @@ macro(_simpledefine FEATURE_NAME FEATURE_TESTNAME FEATURE_STRING FEATURE_DEFAULT
if (feature STREQUAL "${FEATURE_NAME}")
set(def_value "${prefix_arg}_${FEATURE_TESTNAME}")
string(APPEND file_content "
# if ${def_name}
# if defined(${def_name}) && ${def_name}
# define ${def_value} ${FEATURE_STRING}
# else
# define ${def_value} ${FEATURE_DEFAULT_STRING}
@@ -255,7 +262,7 @@ function(write_compiler_detection_header
if (NOT "x${prefix_keyword}" STREQUAL "xPREFIX")
message(FATAL_ERROR "write_compiler_detection_header: PREFIX parameter missing.")
endif()
set(options)
set(options ALLOW_UNKNOWN_COMPILERS ALLOW_UNKNOWN_COMPILER_VERSIONS)
set(oneValueArgs VERSION EPILOG PROLOG OUTPUT_FILES_VAR OUTPUT_DIR)
set(multiValueArgs COMPILERS FEATURES)
cmake_parse_arguments(_WCD "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
@@ -439,10 +446,12 @@ function(write_compiler_detection_header
set(compiler_file_content file_content)
endif()
set(${compiler_file_content} "${${compiler_file_content}}
if(NOT _WCD_ALLOW_UNKNOWN_COMPILER_VERSIONS)
set(${compiler_file_content} "${${compiler_file_content}}
# if !(${_cmake_oldestSupported_${compiler}})
# error Unsupported compiler version
# endif\n")
endif()
set(PREFIX ${prefix_arg}_)
if (_need_hex_conversion)
@@ -473,10 +482,15 @@ function(write_compiler_detection_header
endforeach()
endforeach()
if(pp_if STREQUAL "elif")
string(APPEND file_content "
if(_WCD_ALLOW_UNKNOWN_COMPILERS)
string(APPEND file_content "
# endif\n")
else()
string(APPEND file_content "
# else
# error Unsupported compiler
# endif\n")
endif()
endif()
foreach(feature ${${_lang}_features})
string(TOUPPER ${feature} feature_upper)
@@ -492,12 +506,12 @@ function(write_compiler_detection_header
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>)")
string(APPEND file_content "# if ${def_name}\n${def_standard}\n# else\n${def_alternative}\n# endif\n\n")
string(APPEND file_content "# if defined(${def_name}) && ${def_name}\n${def_standard}\n# else\n${def_alternative}\n# endif\n\n")
endif()
if (feature STREQUAL cxx_alignas)
set(def_value "${prefix_arg}_ALIGNAS(X)")
string(APPEND file_content "
# if ${def_name}
# if defined(${def_name}) && ${def_name}
# define ${def_value} alignas(X)
# elif ${prefix_arg}_COMPILER_IS_GNU || ${prefix_arg}_COMPILER_IS_Clang || ${prefix_arg}_COMPILER_IS_AppleClang
# define ${def_value} __attribute__ ((__aligned__(X)))
@@ -511,7 +525,7 @@ function(write_compiler_detection_header
if (feature STREQUAL cxx_alignof)
set(def_value "${prefix_arg}_ALIGNOF(X)")
string(APPEND file_content "
# if ${def_name}
# if defined(${def_name}) && ${def_name}
# define ${def_value} alignof(X)
# elif ${prefix_arg}_COMPILER_IS_GNU || ${prefix_arg}_COMPILER_IS_Clang || ${prefix_arg}_COMPILER_IS_AppleClang
# define ${def_value} __alignof__(X)
@@ -525,7 +539,7 @@ function(write_compiler_detection_header
if (feature STREQUAL cxx_noexcept)
set(def_value "${prefix_arg}_NOEXCEPT")
string(APPEND file_content "
# if ${def_name}
# if defined(${def_name}) && ${def_name}
# define ${def_value} noexcept
# define ${def_value}_EXPR(X) noexcept(X)
# else
@@ -538,7 +552,7 @@ function(write_compiler_detection_header
if (feature STREQUAL cxx_thread_local)
set(def_value "${prefix_arg}_THREAD_LOCAL")
string(APPEND file_content "
# if ${def_name}
# if defined(${def_name}) && ${def_name}
# define ${def_value} thread_local
# elif ${prefix_arg}_COMPILER_IS_GNU || ${prefix_arg}_COMPILER_IS_Clang || ${prefix_arg}_COMPILER_IS_AppleClang
# define ${def_value} __thread
@@ -554,7 +568,7 @@ function(write_compiler_detection_header
set(def_value "${prefix_arg}_DEPRECATED")
string(APPEND file_content "
# ifndef ${def_value}
# if ${def_name}
# if defined(${def_name}) && ${def_name}
# define ${def_value} [[deprecated]]
# define ${def_value}_MSG(MSG) [[deprecated(MSG)]]
# elif ${prefix_arg}_COMPILER_IS_GNU || ${prefix_arg}_COMPILER_IS_Clang

30
Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
View File

@@ -4,6 +4,7 @@ project(WriteCompilerDetectionHeader)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
include(WriteCompilerDetectionHeader)
include(CheckCXXSourceCompiles)
get_property(cxx_known_features GLOBAL PROPERTY CMAKE_CXX_KNOWN_FEATURES)
get_property(c_known_features GLOBAL PROPERTY CMAKE_C_KNOWN_FEATURES)
@@ -26,7 +27,6 @@ if (NOT CMAKE_CXX_COMPILE_FEATURES AND NOT CMAKE_C_COMPILE_FEATURES)
add_executable(WriteCompilerDetectionHeader "${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp")
if(UNIX OR NOT CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
include(CheckCXXSourceCompiles)
check_cxx_source_compiles("#include \"${CMAKE_CURRENT_BINARY_DIR}/test_compiler_detection.h\"\nint main() { return 0; }\n"
file_include_works
)
@@ -156,3 +156,31 @@ if (CMAKE_C_COMPILER_ID STREQUAL "GNU"
set_defines(WriteCompilerDetectionHeader_C11_multi "EXPECTED_COMPILER_C_FUNCTION_PROTOTYPES;EXPECTED_COMPILER_C_RESTRICT" "")
target_include_directories(WriteCompilerDetectionHeader_C11_multi PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/compiler_multi_files)
endif()
# test for ALLOW_UNKNOWN_COMPILERS
# use a compiler does not match the current one,
# so one always hits the fallback code
if (CMAKE_CXX_COMPILER_ID STREQUAL "SunPro")
set(OTHER_CXX "Intel")
else()
set(OTHER_CXX "SunPro")
endif()
write_compiler_detection_header(
FILE "${CMAKE_CURRENT_BINARY_DIR}/test_compiler_detection_allow_unknown.h"
PREFIX TEST
COMPILERS ${OTHER_CXX}
FEATURES cxx_nullptr
ALLOW_UNKNOWN_COMPILERS
)
# intentionally abuse the TEST_NULLPR variable: this will only work
# with the fallback code.
check_cxx_source_compiles("#include \"${CMAKE_CURRENT_BINARY_DIR}/test_compiler_detection_allow_unknown.h\"
int main() {\n int i = TEST_NULLPTR;\n return 0; }\n"
file_include_works_allow_unknown
)
if (NOT file_include_works_allow_unknown)
message(SEND_ERROR "Inclusion of ${CMAKE_CURRENT_BINARY_DIR}/test_compiler_detection_allow_unknown.h was expected to work, but did not.")
endif()