Fix compilation on OpenBSD

Fixes #2935

glfw/glfw.py

@@ -10,6 +10,7 @@ from typing import Callable, Dict, List, Optional, Tuple
 
 _plat = sys.platform.lower()
 is_linux = 'linux' in _plat
+is_openbsd = 'openbsd' in _plat
 base = os.path.dirname(os.path.abspath(__file__))
 
 
@@ -73,7 +74,9 @@ def init_env(env: Env, pkg_config: Callable, at_least_version: Callable, test_co
     if module in ('x11', 'wayland'):
         ans.cflags.append('-pthread')
         ans.ldpaths.append('-pthread')
-        ans.ldpaths.extend('-lrt -lm -ldl'.split())
+        ans.ldpaths.append('-lm')
+        if not is_openbsd:
+            ans.ldpaths.extend('-lrt -ldl'.split())
         at_least_version('xkbcommon', 0, 5)
 
     if module == 'x11':

setup.py

@@ -263,10 +263,11 @@ def init_env(
         cppflags.append('-DDEBUG_{}'.format(el.upper().replace('-', '_')))
     cflags_ = os.environ.get(
         'OVERRIDE_CFLAGS', (
-            '-Wextra {} -Wno-missing-field-initializers -Wall -Wstrict-prototypes -std=c11'
+            '-Wextra {} -Wno-missing-field-initializers -Wall -Wstrict-prototypes {}'
             ' -pedantic-errors -Werror {} {} -fwrapv {} {} -pipe {} -fvisibility=hidden {}'
         ).format(
             float_conversion,
+            '' if is_openbsd else '-std=c11',
             optimize,
             ' '.join(sanitize_args),
             stack_protector,
@@ -287,7 +288,7 @@ def init_env(
     cppflags += shlex.split(os.environ.get('CPPFLAGS', ''))
     cflags += shlex.split(os.environ.get('CFLAGS', ''))
     ldflags += shlex.split(os.environ.get('LDFLAGS', ''))
-    if not debug and not sanitize:
+    if not debug and not sanitize and not is_openbsd:
         # See https://github.com/google/sanitizers/issues/647
         cflags.append('-flto')
         ldflags.append('-flto')