1 # a waf tool to add autoconf-like macros to the configure section
4 from waflib import Build, Options, Logs, Context
5 from waflib.Configure import conf
6 from waflib.TaskGen import feature
7 from waflib.Tools import c_preproc as preproc
8 from samba_utils import TO_LIST, GET_TARGET_TYPE, SET_TARGET_TYPE, unique_list, mkdir_p
10 missing_headers = set()
12 ####################################################
13 # some autoconf like helpers, to make the transition
14 # to waf a bit easier for those used to autoconf
18 def DEFINE(conf, d, v, add_to_cflags=False, quote=False):
19 '''define a config option'''
20 conf.define(d, v, quote=quote)
22 conf.env.append_value('CFLAGS', '-D%s=%s' % (d, str(v)))
24 def hlist_to_string(conf, headers=None):
25 '''convert a headers list to a set of #include lines'''
27 hlist = conf.env.hlist
30 hlist.extend(TO_LIST(headers))
32 hdrs += '#include <%s>\n' % h
37 def COMPOUND_START(conf, msg):
38 '''start a compound test'''
39 def null_check_message_1(self,*k,**kw):
41 def null_check_message_2(self,*k,**kw):
44 v = getattr(conf.env, 'in_compound', [])
45 if v != [] and v != 0:
46 conf.env.in_compound = v + 1
49 conf.saved_check_message_1 = conf.start_msg
50 conf.start_msg = null_check_message_1
51 conf.saved_check_message_2 = conf.end_msg
52 conf.end_msg = null_check_message_2
53 conf.env.in_compound = 1
57 def COMPOUND_END(conf, result):
58 '''start a compound test'''
59 conf.env.in_compound -= 1
60 if conf.env.in_compound != 0:
62 conf.start_msg = conf.saved_check_message_1
63 conf.end_msg = conf.saved_check_message_2
68 p('not found', 'YELLOW')
75 '''using the nolink type in conf.check() allows us to avoid
76 the link stage of a test, thus speeding it up for tests
77 that where linking is not needed'''
81 def CHECK_HEADER(conf, h, add_headers=False, lib=None):
82 '''check for a header'''
83 if h in missing_headers and lib is None:
85 d = h.upper().replace('/', '_')
86 d = d.replace('.', '_')
87 d = d.replace('-', '_')
89 if CONFIG_SET(conf, d):
91 if not h in conf.env.hlist:
92 conf.env.hlist.append(h)
95 (ccflags, ldflags, cpppath) = library_flags(conf, lib)
97 hdrs = hlist_to_string(conf, headers=h)
100 ret = conf.check(fragment='%s\nint main(void) { return 0; }' % hdrs,
107 msg="Checking for header %s" % h)
109 missing_headers.add(h)
113 if add_headers and not h in conf.env.hlist:
114 conf.env.hlist.append(h)
119 def CHECK_HEADERS(conf, headers, add_headers=False, together=False, lib=None):
120 '''check for a list of headers
122 when together==True, then the headers accumulate within this test.
123 This is useful for interdependent headers
126 if not add_headers and together:
127 saved_hlist = conf.env.hlist[:]
128 set_add_headers = True
130 set_add_headers = add_headers
131 for hdr in TO_LIST(headers):
132 if not CHECK_HEADER(conf, hdr, set_add_headers, lib=lib):
134 if not add_headers and together:
135 conf.env.hlist = saved_hlist
139 def header_list(conf, headers=None, lib=None):
140 '''form a list of headers which exist, as a string'''
142 if headers is not None:
143 for h in TO_LIST(headers):
144 if CHECK_HEADER(conf, h, add_headers=False, lib=lib):
146 return hlist_to_string(conf, headers=hlist)
150 def CHECK_TYPE(conf, t, alternate=None, headers=None, define=None, lib=None, msg=None):
151 '''check for a single type'''
153 define = 'HAVE_' + t.upper().replace(' ', '_')
155 msg='Checking for %s' % t
156 ret = CHECK_CODE(conf, '%s _x' % t,
164 if not ret and alternate:
165 conf.DEFINE(t, alternate)
170 def CHECK_TYPES(conf, list, headers=None, define=None, alternate=None, lib=None):
171 '''check for a list of types'''
173 for t in TO_LIST(list):
174 if not CHECK_TYPE(conf, t, headers=headers,
175 define=define, alternate=alternate, lib=lib):
181 def CHECK_TYPE_IN(conf, t, headers=None, alternate=None, define=None):
182 '''check for a single type with a header'''
183 return CHECK_TYPE(conf, t, headers=headers, alternate=alternate, define=define)
187 def CHECK_VARIABLE(conf, v, define=None, always=False,
188 headers=None, msg=None, lib=None):
189 '''check for a variable declaration (or define)'''
191 define = 'HAVE_%s' % v.upper()
194 msg="Checking for variable %s" % v
196 return CHECK_CODE(conf,
197 # we need to make sure the compiler doesn't
201 void *_x; _x=(void *)&%s; return (int)_x;
216 def CHECK_DECLS(conf, vars, reverse=False, headers=None, always=False):
217 '''check a list of variable declarations, using the HAVE_DECL_xxx form
220 When reverse==True then use HAVE_xxx_DECL instead of HAVE_DECL_xxx
223 for v in TO_LIST(vars):
225 define='HAVE_DECL_%s' % v.upper()
227 define='HAVE_%s_DECL' % v.upper()
228 if not CHECK_VARIABLE(conf, v,
231 msg='Checking for declaration of %s' % v,
233 if not CHECK_CODE(conf,
239 msg='Checking for declaration of %s (as enum)' % v,
248 def CHECK_FUNC(conf, f, link=True, lib=None, headers=None):
249 '''check for a function'''
250 define='HAVE_%s' % f.upper()
254 conf.COMPOUND_START('Checking for %s' % f)
256 if link is None or link:
257 ret = CHECK_CODE(conf,
258 # this is based on the autoconf strategy
260 #define %s __fake__%s
267 #if defined __stub_%s || defined __stub___%s
268 #error "bad glibc stub"
271 int main() { return %s(); }
272 ''' % (f, f, f, f, f, f, f),
281 msg='Checking for %s' % f)
284 ret = CHECK_CODE(conf,
285 # it might be a macro
286 # we need to make sure the compiler doesn't
288 'void *__x = (void *)%s; return (int)__x' % f,
297 msg='Checking for macro %s' % f)
299 if not ret and (link is None or not link):
300 ret = CHECK_VARIABLE(conf, f,
303 msg='Checking for declaration of %s' % f)
304 conf.COMPOUND_END(ret)
309 def CHECK_FUNCS(conf, list, link=True, lib=None, headers=None):
310 '''check for a list of functions'''
312 for f in TO_LIST(list):
313 if not CHECK_FUNC(conf, f, link=link, lib=lib, headers=headers):
319 def CHECK_SIZEOF(conf, vars, headers=None, define=None, critical=True):
320 '''check the size of a type'''
321 for v in TO_LIST(vars):
325 v_define = 'SIZEOF_%s' % v.upper().replace(' ', '_')
326 for size in list((1, 2, 4, 8, 16, 32)):
328 'static int test_array[1 - 2 * !(((long int)(sizeof(%s))) <= %d)];' % (v, size),
333 msg="Checking if size of %s == %d" % (v, size)):
334 conf.DEFINE(v_define, size)
337 if not ret and critical:
338 Logs.error("Couldn't determine size of '%s'" % v)
343 def CHECK_VALUEOF(conf, v, headers=None, define=None):
344 '''check the value of a variable/define'''
348 v_define = 'VALUEOF_%s' % v.upper().replace(' ', '_')
350 'printf("%%u", (unsigned)(%s))' % v,
357 msg="Checking value of %s" % v):
358 return int(conf.env[v_define])
363 def CHECK_CODE(conf, code, define,
364 always=False, execute=False, addmain=True,
365 add_headers=True, mandatory=False,
366 headers=None, msg=None, cflags='', includes='# .',
367 local_include=True, lib=None, link=True,
368 define_ret=False, quote=False,
369 on_target=True, strict=False):
370 '''check if some code compiles and/or runs'''
372 if CONFIG_SET(conf, define):
375 if headers is not None:
376 CHECK_HEADERS(conf, headers=headers, lib=lib)
379 hdrs = header_list(conf, headers=headers, lib=lib)
388 fragment='%s\n int main(void) { %s; return 0; }\n' % (hdrs, code)
390 fragment='%s\n%s\n' % (hdrs, code)
393 msg="Checking for %s" % define
395 cflags = TO_LIST(cflags)
397 # Be strict when relying on a compiler check
398 # Some compilers (e.g. xlc) ignore non-supported features as warnings
401 if conf.env["CC_NAME"] == "gcc":
402 extra_cflags = "-Werror"
403 elif conf.env["CC_NAME"] == "xlc":
404 extra_cflags = "-qhalt=w"
405 cflags.append(extra_cflags)
408 cflags.append('-I%s' % conf.path.abspath())
415 uselib = TO_LIST(lib)
417 (ccflags, ldflags, cpppath) = library_flags(conf, uselib)
419 includes = TO_LIST(includes)
420 includes.extend(cpppath)
422 uselib = [l.upper() for l in uselib]
424 cflags.extend(ccflags)
427 exec_args = conf.SAMBA_CROSS_ARGS(msg=msg)
431 conf.COMPOUND_START(msg)
434 ret = conf.check(fragment=fragment,
436 define_name = define,
445 define_ret=define_ret)
448 conf.DEFINE(define, 0)
449 conf.COMPOUND_END(False)
456 conf.DEFINE(define, 1)
457 conf.COMPOUND_END(True)
459 conf.DEFINE(define, ret, quote=quote)
460 conf.COMPOUND_END(ret)
465 def CHECK_STRUCTURE_MEMBER(conf, structname, member,
466 always=False, define=None, headers=None,
468 '''check for a structure member'''
470 define = 'HAVE_%s' % member.upper()
471 return CHECK_CODE(conf,
472 '%s s; void *_x; _x=(void *)&s.%s' % (structname, member),
480 msg="Checking for member %s in %s" % (member, structname))
484 def CHECK_CFLAGS(conf, cflags, fragment='int main(void) { return 0; }\n'):
485 '''check if the given cflags are accepted by the compiler
487 check_cflags = TO_LIST(cflags)
488 if 'WERROR_CFLAGS' in conf.env:
489 check_cflags.extend(conf.env['WERROR_CFLAGS'])
490 return conf.check(fragment=fragment,
494 ccflags=check_cflags,
495 msg="Checking compiler accepts %s" % cflags)
498 def CHECK_LDFLAGS(conf, ldflags):
499 '''check if the given ldflags are accepted by the linker
501 return conf.check(fragment='int main(void) { return 0; }\n',
505 msg="Checking linker accepts %s" % ldflags)
509 def CONFIG_GET(conf, option):
510 '''return True if a configuration option was found'''
511 if (option in conf.env):
512 return conf.env[option]
517 def CONFIG_SET(conf, option):
518 '''return True if a configuration option was found'''
519 if option not in conf.env:
531 def CONFIG_RESET(conf, option):
532 if option not in conf.env:
536 Build.BuildContext.CONFIG_RESET = CONFIG_RESET
537 Build.BuildContext.CONFIG_SET = CONFIG_SET
538 Build.BuildContext.CONFIG_GET = CONFIG_GET
541 def library_flags(self, libs):
542 '''work out flags from pkg_config'''
546 for lib in TO_LIST(libs):
547 # note that we do not add the -I and -L in here, as that is added by the waf
548 # core. Adding it here would just change the order that it is put on the link line
549 # which can cause system paths to be added before internal libraries
550 extra_ccflags = TO_LIST(getattr(self.env, 'CFLAGS_%s' % lib.upper(), []))
551 extra_ldflags = TO_LIST(getattr(self.env, 'LDFLAGS_%s' % lib.upper(), []))
552 extra_cpppath = TO_LIST(getattr(self.env, 'CPPPATH_%s' % lib.upper(), []))
553 ccflags.extend(extra_ccflags)
554 ldflags.extend(extra_ldflags)
555 cpppath.extend(extra_cpppath)
557 extra_cpppath = TO_LIST(getattr(self.env, 'INCLUDES_%s' % lib.upper(), []))
558 cpppath.extend(extra_cpppath)
559 if 'EXTRA_LDFLAGS' in self.env:
560 ldflags.extend(self.env['EXTRA_LDFLAGS'])
562 ccflags = unique_list(ccflags)
563 ldflags = unique_list(ldflags)
564 cpppath = unique_list(cpppath)
565 return (ccflags, ldflags, cpppath)
569 def CHECK_LIB(conf, libs, mandatory=False, empty_decl=True, set_target=True, shlib=False):
570 '''check if a set of libraries exist as system libraries
572 returns the sublist of libs that do exist as a syslib or []
583 liblist = TO_LIST(libs)
584 for lib in liblist[:]:
585 if GET_TARGET_TYPE(conf, lib) == 'SYSLIB':
589 (ccflags, ldflags, cpppath) = library_flags(conf, lib)
591 res = conf.check(features='c cshlib', fragment=fragment, lib=lib, uselib_store=lib, cflags=ccflags, ldflags=ldflags, uselib=lib.upper(), mandatory=False)
593 res = conf.check(lib=lib, uselib_store=lib, cflags=ccflags, ldflags=ldflags, uselib=lib.upper(), mandatory=False)
597 Logs.error("Mandatory library '%s' not found for functions '%s'" % (lib, list))
600 # if it isn't a mandatory library, then remove it from dependency lists
602 SET_TARGET_TYPE(conf, lib, 'EMPTY')
604 conf.define('HAVE_LIB%s' % lib.upper().replace('-','_').replace('.','_'), 1)
605 conf.env['LIB_' + lib.upper()] = lib
607 conf.SET_TARGET_TYPE(lib, 'SYSLIB')
615 def CHECK_FUNCS_IN(conf, list, library, mandatory=False, checklibc=False,
616 headers=None, link=True, empty_decl=True, set_target=True):
618 check that the functions in 'list' are available in 'library'
619 if they are, then make that library available as a dependency
621 if the library is not available and mandatory==True, then
624 If the library is not available and mandatory==False, then
625 add the library to the list of dependencies to remove from
628 optionally check for the functions first in libc
630 remaining = TO_LIST(list)
631 liblist = TO_LIST(library)
633 # check if some already found
634 for f in remaining[:]:
635 if CONFIG_SET(conf, 'HAVE_%s' % f.upper()):
638 # see if the functions are in libc
640 for f in remaining[:]:
641 if CHECK_FUNC(conf, f, link=True, headers=headers):
646 if GET_TARGET_TYPE(conf, lib) != 'SYSLIB' and empty_decl:
647 SET_TARGET_TYPE(conf, lib, 'EMPTY')
650 checklist = conf.CHECK_LIB(liblist, empty_decl=empty_decl, set_target=set_target)
651 for lib in liblist[:]:
652 if not lib in checklist and mandatory:
653 Logs.error("Mandatory library '%s' not found for functions '%s'" % (lib, list))
658 if not CHECK_FUNC(conf, f, lib=' '.join(checklist), headers=headers, link=link):
665 def IN_LAUNCH_DIR(conf):
666 '''return True if this rule is being run from the launch directory'''
667 return os.path.realpath(conf.path.abspath()) == os.path.realpath(Context.launch_dir)
668 Options.OptionsContext.IN_LAUNCH_DIR = IN_LAUNCH_DIR
672 def SAMBA_CONFIG_H(conf, path=None):
673 '''write out config.h in the right directory'''
674 # we don't want to produce a config.h in places like lib/replace
675 # when we are building projects that depend on lib/replace
676 if not IN_LAUNCH_DIR(conf):
679 # we need to build real code that can't be optimized away to test
680 stack_protect_list = ['-fstack-protector-strong', '-fstack-protector']
681 for stack_protect_flag in stack_protect_list:
682 flag_supported = conf.check(fragment='''
688 while (fgets(t, sizeof(t), stdin));
693 ccflags=[ '-Werror', '-Wp,-D_FORTIFY_SOURCE=2', stack_protect_flag],
695 msg='Checking if compiler accepts %s' % (stack_protect_flag))
697 conf.ADD_CFLAGS('-Wp,-D_FORTIFY_SOURCE=2 %s' % (stack_protect_flag))
700 flag_supported = conf.check(fragment='''
706 while (fgets(t, sizeof(t), stdin));
711 ccflags=[ '-Werror', '-fstack-clash-protection'],
713 msg='Checking if compiler accepts -fstack-clash-protection')
715 conf.ADD_CFLAGS('-fstack-clash-protection')
717 if Options.options.debug:
718 conf.ADD_CFLAGS('-g', testflags=True)
720 if Options.options.developer:
721 conf.env.DEVELOPER_MODE = True
723 conf.ADD_CFLAGS('-g', testflags=True)
724 conf.ADD_CFLAGS('-Wall', testflags=True)
725 conf.ADD_CFLAGS('-Wshadow', testflags=True)
726 conf.ADD_CFLAGS('-Wmissing-prototypes', testflags=True)
727 conf.ADD_CFLAGS('-Wcast-align -Wcast-qual', testflags=True)
728 conf.ADD_CFLAGS('-fno-common', testflags=True)
730 conf.ADD_CFLAGS('-Werror=address', testflags=True)
731 # we add these here to ensure that -Wstrict-prototypes is not set during configure
732 conf.ADD_CFLAGS('-Werror=strict-prototypes -Wstrict-prototypes',
734 conf.ADD_CFLAGS('-Werror=write-strings -Wwrite-strings',
736 conf.ADD_CFLAGS('-Werror-implicit-function-declaration',
738 conf.ADD_CFLAGS('-Werror=pointer-arith -Wpointer-arith',
740 conf.ADD_CFLAGS('-Werror=declaration-after-statement -Wdeclaration-after-statement',
742 conf.ADD_CFLAGS('-Werror=return-type -Wreturn-type',
744 conf.ADD_CFLAGS('-Werror=uninitialized -Wuninitialized',
746 conf.ADD_CFLAGS('-Wimplicit-fallthrough',
748 conf.ADD_CFLAGS('-Werror=strict-overflow -Wstrict-overflow=2',
751 conf.ADD_CFLAGS('-Wformat=2 -Wno-format-y2k', testflags=True)
752 conf.ADD_CFLAGS('-Wno-format-zero-length', testflags=True)
753 conf.ADD_CFLAGS('-Werror=format-security -Wformat-security',
754 testflags=True, prereq_flags='-Wformat')
755 # This check is because for ldb_search(), a NULL format string
756 # is not an error, but some compilers complain about that.
757 if CHECK_CFLAGS(conf, ["-Werror=format", "-Wformat=2"], '''
758 int testformat(char *format, ...) __attribute__ ((format (__printf__, 1, 2)));
766 if not 'EXTRA_CFLAGS' in conf.env:
767 conf.env['EXTRA_CFLAGS'] = []
768 conf.env['EXTRA_CFLAGS'].extend(TO_LIST("-Werror=format"))
770 if Options.options.picky_developer:
771 conf.ADD_NAMED_CFLAGS('PICKY_CFLAGS', '-Werror -Wno-error=deprecated-declarations', testflags=True)
772 conf.ADD_NAMED_CFLAGS('PICKY_CFLAGS', '-Wno-error=tautological-compare', testflags=True)
774 if Options.options.fatal_errors:
775 conf.ADD_CFLAGS('-Wfatal-errors', testflags=True)
777 if Options.options.pedantic:
778 conf.ADD_CFLAGS('-W', testflags=True)
780 if Options.options.address_sanitizer:
781 conf.ADD_CFLAGS('-fno-omit-frame-pointer -O1 -fsanitize=address', testflags=True)
782 conf.ADD_LDFLAGS('-fsanitize=address', testflags=True)
783 conf.env['ADDRESS_SANITIZER'] = True
786 # Let people pass an additional ADDITIONAL_{CFLAGS,LDFLAGS}
787 # environment variables which are only used the for final build.
789 # The CFLAGS and LDFLAGS environment variables are also
790 # used for the configure checks which might impact their results.
791 conf.add_os_flags('ADDITIONAL_CFLAGS')
792 if conf.env.ADDITIONAL_CFLAGS and conf.CHECK_CFLAGS(conf.env['ADDITIONAL_CFLAGS']):
793 conf.env['EXTRA_CFLAGS'].extend(conf.env['ADDITIONAL_CFLAGS'])
794 conf.add_os_flags('ADDITIONAL_LDFLAGS')
795 if conf.env.ADDITIONAL_LDFLAGS and conf.CHECK_LDFLAGS(conf.env['ADDITIONAL_LDFLAGS']):
796 conf.env['EXTRA_LDFLAGS'].extend(conf.env['ADDITIONAL_LDFLAGS'])
799 conf.write_config_header('default/config.h', top=True, remove=False)
801 conf.write_config_header(os.path.join(conf.variant, path), remove=False)
802 for key in conf.env.define_key:
803 conf.undefine(key, from_env=False)
804 conf.env.define_key = []
805 conf.SAMBA_CROSS_CHECK_COMPLETE()
809 def CONFIG_PATH(conf, name, default):
810 '''setup a configurable path'''
811 if not name in conf.env:
812 if default[0] == '/':
813 conf.env[name] = default
815 conf.env[name] = conf.env['PREFIX'] + default
818 def ADD_NAMED_CFLAGS(conf, name, flags, testflags=False, prereq_flags=[]):
819 '''add some CFLAGS to the command line
820 optionally set testflags to ensure all the flags work
822 prereq_flags = TO_LIST(prereq_flags)
825 for f in flags.split():
826 if CHECK_CFLAGS(conf, [f] + prereq_flags):
829 if not name in conf.env:
831 conf.env[name].extend(TO_LIST(flags))
834 def ADD_CFLAGS(conf, flags, testflags=False, prereq_flags=[]):
835 '''add some CFLAGS to the command line
836 optionally set testflags to ensure all the flags work
838 ADD_NAMED_CFLAGS(conf, 'EXTRA_CFLAGS', flags, testflags=testflags,
839 prereq_flags=prereq_flags)
842 def ADD_LDFLAGS(conf, flags, testflags=False):
843 '''add some LDFLAGS to the command line
844 optionally set testflags to ensure all the flags work
846 this will return the flags that are added, if any
850 for f in flags.split():
851 if CHECK_LDFLAGS(conf, f):
854 if not 'EXTRA_LDFLAGS' in conf.env:
855 conf.env['EXTRA_LDFLAGS'] = []
856 conf.env['EXTRA_LDFLAGS'].extend(TO_LIST(flags))
861 def ADD_EXTRA_INCLUDES(conf, includes):
862 '''add some extra include directories to all builds'''
863 if not 'EXTRA_INCLUDES' in conf.env:
864 conf.env['EXTRA_INCLUDES'] = []
865 conf.env['EXTRA_INCLUDES'].extend(TO_LIST(includes))
869 def CURRENT_CFLAGS(bld, target, cflags, allow_warnings=False, hide_symbols=False):
870 '''work out the current flags. local flags are added first'''
871 ret = TO_LIST(cflags)
872 if not 'EXTRA_CFLAGS' in bld.env:
875 list = bld.env['EXTRA_CFLAGS'];
877 if not allow_warnings and 'PICKY_CFLAGS' in bld.env:
878 list = bld.env['PICKY_CFLAGS'];
880 if hide_symbols and bld.env.HAVE_VISIBILITY_ATTR:
881 ret.append(bld.env.VISIBILITY_CFLAGS)
886 def CHECK_CC_ENV(conf):
887 """trim whitespaces from 'CC'.
888 The build farm sometimes puts a space at the start"""
889 if os.environ.get('CC'):
890 conf.env.CC = TO_LIST(os.environ.get('CC'))
891 if len(conf.env.CC) == 1:
892 # make for nicer logs if just a single command
893 conf.env.CC = conf.env.CC[0]
897 def SETUP_CONFIGURE_CACHE(conf, enable):
898 '''enable/disable cache of configure results'''
900 # when -C is chosen, we will use a private cache and will
901 # not look into system includes. This roughtly matches what
902 # autoconf does with -C
903 cache_path = os.path.join(conf.bldnode.abspath(), '.confcache')
905 Options.cache_global = os.environ['WAFCACHE'] = cache_path
907 # when -C is not chosen we will not cache configure checks
908 # We set the recursion limit low to prevent waf from spending
909 # a lot of time on the signatures of the files.
910 Options.cache_global = os.environ['WAFCACHE'] = ''
911 preproc.recursion_limit = 1
912 # in either case we don't need to scan system includes
913 preproc.go_absolute = False
917 def SAMBA_CHECK_UNDEFINED_SYMBOL_FLAGS(conf):
918 # we don't want any libraries or modules to rely on runtime
919 # resolution of symbols
920 if not sys.platform.startswith("openbsd"):
921 conf.env.undefined_ldflags = conf.ADD_LDFLAGS('-Wl,-no-undefined', testflags=True)
923 if not sys.platform.startswith("openbsd") and conf.env.undefined_ignore_ldflags == []:
924 if conf.CHECK_LDFLAGS(['-undefined', 'dynamic_lookup']):
925 conf.env.undefined_ignore_ldflags = ['-undefined', 'dynamic_lookup']