Fix compilation with non-Linux PAM on macOS

login/meson.build

@@ -72,9 +72,18 @@ endif
 if get_option('pam-glome')
     cc = meson.get_compiler('c')
     libpam = cc.find_library('pam')
+
+    args = ['-DPAM_GLOME']
+    pam_ext_present = cc.has_function('pam_syslog',
+        dependencies: libpam,
+        prefix: '#include <security/pam_ext.h>')
+    if pam_ext_present
+        args += ['-DPAM_GLOME_LINUX']
+    endif
+
     pam_glome = shared_library(
         'pam_glome', ['pam.c', 'login.c'],
-        c_args : '-DPAM_GLOME',
+        c_args : args,
         dependencies : [libpam, openssl_dep],
         link_with : [glome_lib, login_lib],
         include_directories : glome_incdir,

login/pam.c

@@ -15,8 +15,12 @@
 #include <errno.h>
 #include <limits.h>
 #include <openssl/crypto.h>
-#include <security/pam_ext.h>
 #include <security/pam_modules.h>
+#ifdef PAM_GLOME_LINUX
+# include <security/pam_ext.h>
+#else
+# include <security/pam_appl.h>
+#endif
 #include <stdlib.h>
 #include <string.h>
 #include <syslog.h>
@@ -29,6 +33,11 @@
 
 #define MODULE_NAME "pam_glome"
 
+#ifndef PAM_GLOME_LINUX
+void pam_syslog(void *pamh, ...) { (void)(pamh); }
+void pam_vsyslog(void *pamh, ...) { (void)(pamh); }
+#endif
+
 #define MAX_ERROR_MESSAGE_SIZE 4095
 
 #define UNUSED(var) (void)(var)