project('has function', 'c', 'cpp') host_system = host_machine.system() # This is used in the `test_compiler_check_flags_order` unit test unit_test_args = '-I/tmp' defines_has_builtin = '''#ifndef __has_builtin #error "no __has_builtin" #endif ''' compilers = [meson.get_compiler('c'), meson.get_compiler('cpp')] foreach cc : compilers if not cc.has_function('printf', prefix : '#include', args : unit_test_args) error('"printf" function not found (should always exist).') endif # Should also be able to detect it without specifying the header # We check for a different function here to make sure the result is # not taken from a cache (ie. the check above) # On MSVC fprintf is defined as an inline function in the header, so it cannot # be found without the include. if not ['msvc', 'intel-cl'].contains(cc.get_id()) assert(cc.has_function('fprintf', args : unit_test_args), '"fprintf" function not found without include (on !msvc).') else assert(cc.has_function('fprintf', prefix : '#include ', args : unit_test_args), '"fprintf" function not found with include (on msvc).') # Compiler intrinsics assert(cc.has_function('strcmp'), 'strcmp intrinsic should have been found on MSVC') assert(cc.has_function('strcmp', prefix : '#include '), 'strcmp intrinsic should have been found with #include on MSVC') endif if cc.has_function('hfkerhisadf', prefix : '#include', args : unit_test_args) error('Found nonexistent function "hfkerhisadf".') endif if cc.has_function('hfkerhisadf', args : unit_test_args) error('Found nonexistent function "hfkerhisadf".') endif # With glibc (before 2.32, see below) on Linux, lchmod is a stub that will # always return an error, we want to detect that and declare that the # function is not available. # We can't check for the C library used here of course, but the main # alternative Linux C library (musl) doesn't use glibc's stub mechanism; # also, it has implemented lchmod since 2013, so it should be safe to check # that lchmod is available on Linux when not using glibc. if host_system == 'linux' or host_system == 'darwin' assert (cc.has_function('poll', prefix : '#include ', args : unit_test_args), 'couldn\'t detect "poll" when defined by a header') lchmod_prefix = '#include \n#include ' has_lchmod = cc.has_function('lchmod', prefix : lchmod_prefix, args : unit_test_args) if host_system == 'linux' # __GLIBC__ macro can be retrieved by including almost any C library header glibc_major = cc.get_define('__GLIBC__', prefix: '#include ', args: unit_test_args) # __GLIBC__ will only be set for glibc if glibc_major != '' glibc_minor = cc.get_define('__GLIBC_MINOR__', prefix: '#include ', args: unit_test_args) glibc_vers = '@0@.@1@'.format(glibc_major, glibc_minor) message('GLIBC version:', glibc_vers) # lchmod was implemented in glibc 2.32 (https://sourceware.org/pipermail/libc-announce/2020/000029.html) if glibc_vers.version_compare('<2.32') assert (not has_lchmod, '"lchmod" check should have failed') else assert (has_lchmod, '"lchmod" check should have succeeded') endif else # Other C libraries for Linux should have lchmod assert (has_lchmod, '"lchmod" check should have succeeded') endif else # macOS and *BSD have lchmod assert (has_lchmod, '"lchmod" check should have succeeded') endif # Check that built-ins are found properly both with and without headers assert(cc.has_function('alloca', args : unit_test_args), 'built-in alloca must be found on ' + host_system) assert(cc.has_function('alloca', prefix : '#include ', args : unit_test_args), 'built-in alloca must be found with #include') if not cc.compiles(defines_has_builtin, args : unit_test_args) assert(not cc.has_function('alloca', prefix : '#include \n#undef alloca', args : unit_test_args), 'built-in alloca must not be found with #include and #undef') endif endif # For some functions one needs to define _GNU_SOURCE before including the # right headers to get them picked up. Make sure we can detect these functions # as well without any prefix if cc.has_header_symbol('sys/socket.h', 'recvmmsg', prefix : '#define _GNU_SOURCE', args : unit_test_args) # We assume that if recvmmsg exists sendmmsg does too assert (cc.has_function('sendmmsg', args : unit_test_args), 'Failed to detect function "sendmmsg" (should always exist).') endif # We should be able to find GCC and Clang __builtin functions if ['gcc', 'clang'].contains(cc.get_id()) # __builtin_constant_p is documented to exist at least as far back as # GCC 2.95.3 assert(cc.has_function('__builtin_constant_p', args : unit_test_args), '__builtin_constant_p must be found under gcc and clang') endif endforeach