Clean up include/stdinc.h and librb/include/rb_lib.h amdj/fix-buildsys-headers

- Unconditionally require stdbool.h in IRCd

  We are a C99 project anyway (configure.ac and meson.build both
  require a C99 compiler), so this header will always be present

  This removes the awful hack defining bool, true, and false in
  its absense, which was creating build errors when using meson,
  because meson.build did not set the HAVE_STDBOOL_H macro

- Modernise definition of alloca(3) according to GNU guidance

  This was in both librb and IRCd, while it only needs to be in
  the former

- Fix missing endianness check in librb/meson.build

  IRCd and librb both use the WORDS_BIGENDIAN macro, which was
  only being set by their configure.ac (with the AC_C_BIGENDIAN
  M4 macro)

  Since IRCd's stdinc.h includes librb's rb_lib.h, which then
  includes librb's librb-config.h, which would have the macro
  defined there, we only need to check for it in librb, so we
  can remove the endianness check from IRCd's configure.ac and
  don't need to add it to IRCd's meson.build

- Use __has_attribute to detect whether compiler attributes are
  available

  This is supported by gcc (5+), clang (2.9+), and ICC (17+)

- Add a __noreturn macro for __attribute__((__noreturn__)) and
  adjust the codebase to use that

- Remove inclusion of headers that are only used by librb

- Remove inclusion of headers that are included in rb_lib.h
  because stdinc.h includes rb_lib.h anyway

- Remove the checks for headers and functions from the IRCd
  configure.ac and meson.build that are only used by librb

- Alphabetise checks for headers and functions (by the name of
  the macro they define) in the meson.build files

- Use check_header() instead of has_header() in meson to see if
  it is actually possible to compile code using the header

- Remove dead code using srand48(3) which has never been
  compiled because neither build system has ever set the
  HAVE_SRAND48 macro and the surrounding code makes no use of
  this libc RNG

- Remove the TLS defines from IRCd's meson.build because librb's
  meson.build already defines them and IRCd pulls those in

19 files changed, 132 insertions, 276 deletions

diff --git a/authd/authd.c b/authd/authd.c
index 23ac2a4b..185dfae6 100644
--- a/authd/authd.c
+++ b/authd/authd.c
@@ -25,7 +25,7 @@
 
 #define MAXPARA 10
 
-static void error_cb(rb_helper *helper) __attribute__((noreturn));
+static void error_cb(rb_helper *helper) __noreturn;
 static void handle_reload(int parc, char *parv[]);
 static void handle_stat(int parc, char *parv[]);
 static void handle_options(int parc, char *parv[]);
diff --git a/authd/res.c b/authd/res.c
index b892f6fb..88188382 100644
--- a/authd/res.c
+++ b/authd/res.c
@@ -224,9 +224,6 @@ static void start_resolver(void)
  */
 void init_resolver(void)
 {
-#ifdef HAVE_SRAND48
-	srand48(rb_current_time());
-#endif
 	start_resolver();
 }
 
diff --git a/bandb/bandb.c b/bandb/bandb.c
index 85487447..54608eee 100644
--- a/bandb/bandb.c
+++ b/bandb/bandb.c
@@ -237,7 +237,7 @@ parse_request(rb_helper *helper)
 
 
 static void
-error_cb(rb_helper *helper) __attribute__((noreturn));
+error_cb(rb_helper *helper) __noreturn;
 
 static void
 error_cb(rb_helper *helper)
@@ -282,7 +282,7 @@ setup_signals(void)
 
 
 static void
-db_error_cb(const char *errstr) __attribute__((noreturn));
+db_error_cb(const char *errstr) __noreturn;
 
 static void
 db_error_cb(const char *errstr)
diff --git a/bandb/bantool.c b/bandb/bantool.c
index 5563a4a9..d4acc892 100644
--- a/bandb/bantool.c
+++ b/bandb/bantool.c
@@ -118,7 +118,7 @@ static void db_reclaim_slack(void);
 static void export_config(const char *conf, int id);
 static void import_config(const char *conf, int id);
 static void check_schema(void);
-static void print_help(int i_exit) __attribute__((noreturn));
+static void print_help(int i_exit) __noreturn;
 static void wipe_schema(void);
 static void drop_dupes(const char *user, const char *host, const char *t);
 
diff --git a/configure.ac b/configure.ac
index d86eff8e..61290c4e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -123,16 +123,15 @@ AC_DEFINE_DIR([PKGLIBEXECDIR], [pkglibexecdir], [Directory where binaries the IR
 dnl Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_STDBOOL
-
-AC_CHECK_HEADERS([crypt.h sys/param.h sys/syslog.h sys/epoll.h machine/endian.h])
+AS_IF([test "x$ac_cv_header_stdbool_h" = "xno"], [
+    AC_MSG_ERROR([stdbool.h is required])
+])
+AC_CHECK_HEADERS([crypt.h strings.h sys/param.h])
 
 dnl Stuff that the memory manager (imalloc) depends on
 dnl ==================================================
 
 AC_C_CONST
-if test "$ac_cv_header_machine_endian_h" = "no" ; then
-    AC_C_BIGENDIAN
-fi
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_CHECK_SIZEOF(short)
@@ -162,21 +161,14 @@ fi
 
 AC_SUBST(CRYPT_LIB)
 
-AC_C_BIGENDIAN
-
 dnl Check for stdarg.h - if we can't find it, halt configure
 AC_CHECK_HEADER(stdarg.h, , [AC_MSG_ERROR([** stdarg.h could not be found - solanum will not compile without it **])])
-AC_CHECK_FUNCS([strlcat strlcpy])
 
 AC_TYPE_INT16_T
 AC_TYPE_INT32_T
 
 AC_CHECK_TYPES([uintptr_t])
 
-dnl check for various functions...
-
-AC_FUNC_ALLOCA
-
 dnl OpenSSL support
 AC_MSG_CHECKING(for OpenSSL)
 AC_ARG_ENABLE(openssl,
diff --git a/include/ircd.h b/include/ircd.h
index 28df4d5b..9edc7b68 100644
--- a/include/ircd.h
+++ b/include/ircd.h
@@ -103,6 +103,6 @@ extern bool ircd_ssl_ok;
 extern bool ircd_zlib_ok;
 extern int maxconnections;
 
-void ircd_shutdown(const char *reason) __attribute__((noreturn));
+void ircd_shutdown(const char *reason) __noreturn;
 
 #endif
diff --git a/include/ircd_defs.h b/include/ircd_defs.h
index 98b5cea4..9ca5b62c 100644
--- a/include/ircd_defs.h
+++ b/include/ircd_defs.h
@@ -37,25 +37,6 @@
 
 #include "defaults.h"
 
-/* For those unfamiliar with GNU format attributes, a is the 1 based
- * argument number of the format string, and b is the 1 based argument
- * number of the variadic ... */
-#ifdef __GNUC__
-#define AFP(a,b) __attribute__((format (printf, a, b)))
-#else
-#define AFP(a,b)
-#endif
-
-/*
- * This ensures that __attribute__((deprecated)) is not used in for example
- * sun CC, since it's a GNU-specific extension. -nenolod
- */
-#ifdef __GNUC__
-#define IRC_DEPRECATED __attribute__((deprecated))
-#else
-#define IRC_DEPRECATED
-#endif
-
 #ifndef MAX
 #define MAX(a, b)	((a) > (b) ? (a) : (b))
 #endif
diff --git a/include/ircd_getopt.h b/include/ircd_getopt.h
index bd41cbe8..16fdf7dd 100644
--- a/include/ircd_getopt.h
+++ b/include/ircd_getopt.h
@@ -37,7 +37,7 @@ struct lgetopt
 
 extern struct lgetopt myopts[];
 
-void usage(const char *) __attribute__((noreturn));
+void usage(const char *) __noreturn;
 void parseargs(int *, char * const **, struct lgetopt *);
 
 #endif /* __GETOPT_H_INCLUDED__ */
diff --git a/include/restart.h b/include/restart.h
index 770b246f..ca42fe5a 100644
--- a/include/restart.h
+++ b/include/restart.h
@@ -25,7 +25,7 @@
 #ifndef INCLUDED_restart_h
 #define INCLUDED_restart_h
 
-void restart(const char *) __attribute__((noreturn));
-void server_reboot(void) __attribute__((noreturn));
+void restart(const char *) __noreturn;
+void server_reboot(void) __noreturn;
 
 #endif
diff --git a/include/stdinc.h b/include/stdinc.h
index e6952f6d..13c7f885 100644
--- a/include/stdinc.h
+++ b/include/stdinc.h
@@ -21,122 +21,38 @@
  *
  */
 
+#ifndef INCLUDED_stdinc_h
+#define INCLUDED_stdinc_h 1
+
 #include "rb_lib.h"
 #include "ircd_defs.h"  /* Needed for some reasons here -- dwr */
 
-/* AIX requires this to be the first thing in the file.  */
-#ifdef __GNUC__
-#undef alloca
-#define alloca __builtin_alloca
-#else
-# ifdef _MSC_VER
-#  include <malloc.h>
-#  define alloca _alloca
-# else
-#  if HAVE_ALLOCA_H
-#   include <alloca.h>
-#  else
-#   ifdef _AIX
- #pragma alloca
-#   else
-#    ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-#    endif
-#   endif
-#  endif
-# endif
-#endif
-
-
-#ifdef HAVE_STDLIB_H
+#include <stdbool.h>
 #include <stdlib.h>
-#endif
-#ifdef STRING_WITH_STRINGS
-# include <string.h>
-# include <strings.h>
-#else
-# ifdef HAVE_STRING_H
-#  include <string.h>
-# else
-#  ifdef HAVE_STRINGS_H
-#   include <strings.h>
-#  endif
-# endif
-#endif
-
-#include <stddef.h>
 
-#ifdef HAVE_STDBOOL_H
-# include <stdbool.h>
-#else
-# ifndef HAVE__BOOL
-#  ifdef __cplusplus
-typedef bool _Bool;
-#  else
-#   define _Bool signed char
-#  endif
-# endif
-# define bool _Bool
-# define false 0
-# define true 1
-# define __bool_true_false_are_defined 1
-#endif
-
-
-#include <stdint.h>
-#include <assert.h>
-#include <stdio.h>
-#include <time.h>
-#include <fcntl.h>
-#include <stdarg.h>
-#include <signal.h>
 #include <dirent.h>
-#include <ctype.h>
-
-#include <limits.h>
+#include <errno.h>
+#include <string.h>
+#ifdef HAVE_STRINGS_H
+#  include <strings.h>
+#endif
 #include <unistd.h>
-#include <sys/time.h>
-#include <sys/types.h>
+
 #include <sys/file.h>
 #include <sys/resource.h>
-
 #include <sys/stat.h>
+#include <sys/time.h>
 
 #ifdef HAVE_SYS_PARAM_H
-#include <sys/param.h>
+#  include <sys/param.h>
 #endif
 
-#include <errno.h>
-#include <sys/uio.h>
-
-#if defined(__INTEL_COMPILER) || defined(__GNUC__)
-# ifdef __unused
-#  undef __unused
-# endif
-# ifdef __printf
-#  undef __printf
-# endif
-# ifdef __noreturn
-#  undef __noreturn
-# endif
-
-# define __unused __attribute__((__unused__))
-# define __printf(x) __attribute__((__format__ (__printf__, x, x + 1)))
-# define __noreturn __attribute__((__noreturn__))
+#if defined(strdupa)
+#  define LOCAL_COPY(s)         strdupa(s)
+#elif defined(__GNUC__) || defined(__INTEL_COMPILER)
+#  define LOCAL_COPY(s)         __extension__({ char *_s = alloca(strlen(s) + 1); strcpy(_s, s); _s; })
 #else
-# define __unused
-# define __printf
-# define __noreturn
+#  define LOCAL_COPY(s)         strcpy(alloca(strlen(s) + 1), s) /* XXX Is that allowed? */
 #endif
 
-
-
-#ifdef strdupa
-#define LOCAL_COPY(s) strdupa(s)
-#else
-#if defined(__INTEL_COMPILER) || defined(__GNUC__)
-# define LOCAL_COPY(s) __extension__({ char *_s = alloca(strlen(s) + 1); strcpy(_s, s); _s; })
-#else
-# define LOCAL_COPY(s) strcpy(alloca(strlen(s) + 1), s) /* XXX Is that allowed? */
-#endif /* defined(__INTEL_COMPILER) || defined(__GNUC__) */
-#endif /* strdupa */
+#endif /* !INCLUDED_stdinc_h */
diff --git a/ircd/bandbi.c b/ircd/bandbi.c
index cc709484..243581ed 100644
--- a/ircd/bandbi.c
+++ b/ircd/bandbi.c
@@ -47,7 +47,7 @@
 #include "operhash.h"
 
 static void
-bandb_handle_failure(rb_helper *helper, char **parv, int parc) __attribute__((noreturn));
+bandb_handle_failure(rb_helper *helper, char **parv, int parc) __noreturn;
 
 static char bandb_add_letter[LAST_BANDB_TYPE] = {
 	'K', 'D', 'X', 'R'
diff --git a/ircd/ircd.c b/ircd/ircd.c
index caea26d7..eab29794 100644
--- a/ircd/ircd.c
+++ b/ircd/ircd.c
@@ -66,7 +66,7 @@
 #include "operhash.h"
 
 static void
-ircd_die_cb(const char *str) __attribute__((noreturn));
+ircd_die_cb(const char *str) __noreturn;
 
 /* /quote set variables */
 struct SetOptions GlobalSetOptions;
diff --git a/ircd/ircd_signal.c b/ircd/ircd_signal.c
index 22472529..b08af83a 100644
--- a/ircd/ircd_signal.c
+++ b/ircd/ircd_signal.c
@@ -55,7 +55,7 @@ sigchld_handler(int sig)
  * sigterm_handler - exit the server
  */
 static void
-sigterm_handler(int sig) __attribute__((noreturn));
+sigterm_handler(int sig) __noreturn;
 
 static void
 sigterm_handler(int sig)
diff --git a/librb/configure.ac b/librb/configure.ac
index 45b77325..c1fd55c3 100644
--- a/librb/configure.ac
+++ b/librb/configure.ac
@@ -400,10 +400,6 @@ AC_CONFIG_COMMANDS([include/librb-config.h],
 
 _______EOF
 
-if test "x$rb_alloca_h" = "xyes"; then
-	echo '#define RB_HAVE_ALLOCA_H 1' >> $outfile
-fi
-
 echo '#include <stdlib.h>' >> $outfile
 echo '#include <stddef.h>' >> $outfile
 echo '#include <string.h>' >> $outfile
@@ -454,11 +450,6 @@ fi
 	if test x$ac_cv_header_memory_h = xyes; then
 		rb_header_memory_h=yes
 	fi
-	if test "x${ac_cv_working_alloca_h+set}" = xset ; then
-		rb_alloca_h="$ac_cv_working_alloca_h"
-	else
-		rb_alloc_h="$ac_cv_header_alloca_h"
-	fi
 	if test x$ac_cv_member_struct_sockaddr_sa_len = xyes; then
 		rb_sockaddr_sa_len=yes
 	fi
diff --git a/librb/include/rb_lib.h b/librb/include/rb_lib.h
index 008bce89..c2d87b36 100644
--- a/librb/include/rb_lib.h
+++ b/librb/include/rb_lib.h
@@ -2,90 +2,79 @@
 #define RB_LIB_H 1
 
 #include <librb-config.h>
-#include <stdio.h>
-#include <limits.h>
-#include <stdarg.h>
-#include <assert.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <ctype.h>
-
-#ifdef __GNUC__
-#undef alloca
-#define alloca __builtin_alloca
-#else
-# ifdef _MSC_VER
-#  include <malloc.h>
-#  define alloca _alloca
-# else
-#  if RB_HAVE_ALLOCA_H
-#   include <alloca.h>
-#  else
-#   ifdef _AIX
-#pragma alloca
-#   else
-#    ifndef alloca		/* predefined by HP cc +Olibcalls */
-char *alloca();
-#    endif
-#   endif
-#  endif
-# endif
-#endif /* __GNUC__ */
 
-#ifdef __GNUC__
+#include <stddef.h>
+#include <sys/types.h>
 
-#ifdef rb_likely
-#undef rb_likely
-#endif
-#ifdef rb_unlikely
-#undef rb_unlikely
-#endif
-
-#if __GNUC__ == 2 && __GNUC_MINOR__ < 96
-# define __builtin_expect(x, expected_value) (x)
+#if defined(HAVE_ALLOCA_H)
+#  include <alloca.h>
+#elif !defined(alloca)
+#  if defined(__GNUC__)
+#    define alloca              __builtin_alloca
+#  elif defined(_AIX)
+#    define alloca              __alloca
+#  elif !defined(HAVE_ALLOCA)
+void *alloca(size_t);
+#  endif
 #endif
 
-#define rb_likely(x)       __builtin_expect(!!(x), 1)
-#define rb_unlikely(x)     __builtin_expect(!!(x), 0)
-
-#else /* !__GNUC__ */
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
 
-#define UNUSED(x) x
+#include <assert.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <time.h>
 
 #ifdef rb_likely
-#undef rb_likely
+#  undef rb_likely
 #endif
 #ifdef rb_unlikely
-#undef rb_unlikely
+#  undef rb_unlikely
 #endif
-#define rb_likely(x)	(x)
-#define rb_unlikely(x)	(x)
-#endif
-
-#ifndef HOSTIPLEN
-#define HOSTIPLEN	53
+#ifdef __GNUC__
+#  define rb_likely(x)          __builtin_expect(!!(x), 1)
+#  define rb_unlikely(x)        __builtin_expect(!!(x), 0)
+#else
+#  define rb_likely(x)          (x)
+#  define rb_unlikely(x)        (x)
 #endif
 
 
 /* For those unfamiliar with GNU format attributes, a is the 1 based
  * argument number of the format string, and b is the 1 based argument
  * number of the variadic ... */
-#ifdef __GNUC__
-#define AFP(a,b) __attribute__((format (printf, a, b)))
+#if __has_attribute(__format__)
+#  define AFP(a, b)             __attribute__((__format__(printf, a, b)))
 #else
-#define AFP(a,b)
+#  define AFP(a, b)
+#endif
+
+#if __has_attribute(__noreturn__)
+#  define __noreturn            __attribute__((__noreturn__))
+#else
+#  define __noreturn
+#endif
+
+#if __has_attribute(__unused__)
+#  define __unused              __attribute__((__unused__))
+#else
+#  define __unused
 #endif
 
 
 #ifdef __GNUC__
-#define slrb_assert(expr)	(							\
+#  define slrb_assert(expr)	(							\
 			rb_likely((expr)) || (						\
 				rb_lib_log( 						\
 				"file: %s line: %d (%s): Assertion failed: (%s)",	\
 				__FILE__, __LINE__, __PRETTY_FUNCTION__, #expr), 0) 	\
 			)
 #else
-#define slrb_assert(expr)	(							\
+#  define slrb_assert(expr)	(							\
 			rb_likely((expr)) || (						\
 				rb_lib_log( 						\
 				"file: %s line: %d: Assertion failed: (%s)",		\
@@ -95,27 +84,28 @@ char *alloca();
 
 /* evaluates to true if assertion fails */
 #ifdef SOFT_ASSERT
-#define lrb_assert(expr) 	(!slrb_assert(expr))
+#  define lrb_assert(expr) 	(!slrb_assert(expr))
 #else
-#define lrb_assert(expr)	(assert(slrb_assert(expr)), 0)
+#  define lrb_assert(expr)	(assert(slrb_assert(expr)), 0)
 #endif
 
 #ifdef RB_SOCKADDR_HAS_SA_LEN
-#define ss_len sa_len
+#  define ss_len sa_len
 #endif
 
 #define GET_SS_FAMILY(x) (((const struct sockaddr *)(x))->sa_family)
 #define SET_SS_FAMILY(x, y) ((((struct sockaddr *)(x))->sa_family) = y)
+
 #ifdef RB_SOCKADDR_HAS_SA_LEN
-#define SET_SS_LEN(x, y)	do {							\
+#  define SET_SS_LEN(x, y)	do {							\
 					struct sockaddr *_storage;		\
 					_storage = ((struct sockaddr *)(x));\
 					_storage->sa_len = (y);				\
 				} while (0)
-#define GET_SS_LEN(x) (((struct sockaddr *)(x))->sa_len)
+#  define GET_SS_LEN(x) (((struct sockaddr *)(x))->sa_len)
 #else /* !RB_SOCKADDR_HAS_SA_LEN */
-#define SET_SS_LEN(x, y) (((struct sockaddr *)(x))->sa_family = ((struct sockaddr *)(x))->sa_family)
-#define GET_SS_LEN(x) (((struct sockaddr *)(x))->sa_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6))
+#  define SET_SS_LEN(x, y) (((struct sockaddr *)(x))->sa_family = ((struct sockaddr *)(x))->sa_family)
+#  define GET_SS_LEN(x) (((struct sockaddr *)(x))->sa_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6))
 #endif
 
 #define GET_SS_PORT(x) (((struct sockaddr *)(x))->sa_family == AF_INET ? ((struct sockaddr_in *)(x))->sin_port : ((struct sockaddr_in6 *)(x))->sin6_port)
@@ -127,24 +117,20 @@ char *alloca();
 					} \
 				} while (0)
 
+#ifndef HOSTIPLEN
+#  define HOSTIPLEN     53
+#endif
+
 #ifndef INADDRSZ
-#define INADDRSZ 4
+#  define INADDRSZ      4
 #endif
 
 #ifndef IN6ADDRSZ
-#define IN6ADDRSZ 16
+#  define IN6ADDRSZ     16
 #endif
 
 #ifndef INT16SZ
-#define INT16SZ 2
-#endif
-
-#ifndef UINT16_MAX
-#define UINT16_MAX (65535U)
-#endif
-
-#ifndef UINT32_MAX
-#define UINT32_MAX (4294967295U)
+#  define INT16SZ       2
 #endif
 
 
@@ -155,14 +141,14 @@ typedef void die_cb(const char *buffer);
 char *rb_ctime(const time_t, char *, size_t);
 char *rb_date(const time_t, char *, size_t);
 void rb_lib_log(const char *, ...);
-void rb_lib_restart(const char *, ...) __attribute__((noreturn));
+void rb_lib_restart(const char *, ...) __noreturn;
 void rb_lib_die(const char *, ...);
 void rb_set_time(void);
 const char *rb_lib_version(void);
 
 void rb_lib_init(log_cb * xilog, restart_cb * irestart, die_cb * idie, int closeall, int maxfds,
 		 size_t dh_size, size_t fd_heap_size);
-void rb_lib_loop(long delay) __attribute__((noreturn));
+void rb_lib_loop(long delay) __noreturn;
 
 time_t rb_current_time(void);
 const struct timeval *rb_current_time_tv(void);
@@ -184,7 +170,6 @@ int rb_setenv(const char *, const char *, int);
 
 pid_t rb_waitpid(pid_t pid, int *status, int options);
 pid_t rb_getpid(void);
-//unsigned int rb_geteuid(void);
 
 
 #include <rb_tools.h>
diff --git a/librb/meson.build b/librb/meson.build
index f6bdee9d..936cd13f 100644
--- a/librb/meson.build
+++ b/librb/meson.build
@@ -44,31 +44,33 @@ librb_conf_data = configuration_data()
 rt_dep = cc.find_library('rt', required: false)
 
 librb_checks = {
-  'HAVE_CRYPT_H': cc.has_header('crypt.h'),
-  'HAVE_SYS_POLL_H': cc.has_header('sys/poll.h'),
-  'HAVE_SYS_EPOLL_H': cc.has_header('sys/epoll.h'),
-  'HAVE_SYS_SELECT_H': cc.has_header('sys/select.h'),
-  'HAVE_SYS_DEVPOLL_H': cc.has_header('sys/devpoll.h'),
-  'HAVE_SYS_EVENT_H': cc.has_header('sys/event.h'),
-  'HAVE_PORT_H': cc.has_header('port.h'),
-  'HAVE_SYS_SIGNALFD_H': cc.has_header('sys/signalfd.h'),
-  'HAVE_SYS_TIMERFD_H': cc.has_header('sys/timerfd.h'),
-  'TIME_WITH_SYS_TIME': cc.has_header('time.h'),
-  'HAVE_GETEXECNAME': cc.has_function('getexecname'),
-  'HAVE_STRLCPY': cc.has_function('strlcpy'),
-  'HAVE_STRLCAT': cc.has_function('strlcat'),
-  'HAVE_STRCASESTR': cc.has_function('strcasestr'),
-  'HAVE_SIGNALFD': cc.has_function('signalfd'),
+  'HAVE_ALLOCA_H': cc.check_header('alloca.h'),
+  'HAVE_CRYPT_H': cc.check_header('crypt.h'),
+  'HAVE_PORT_H': cc.check_header('port.h'),
+  'HAVE_SYS_DEVPOLL_H': cc.check_header('sys/devpoll.h'),
+  'HAVE_SYS_EPOLL_H': cc.check_header('sys/epoll.h'),
+  'HAVE_SYS_EVENT_H': cc.check_header('sys/event.h'),
+  'HAVE_SYS_POLL_H': cc.check_header('sys/poll.h'),
+  'HAVE_SYS_SELECT_H': cc.check_header('sys/select.h'),
+  'HAVE_SYS_SIGNALFD_H': cc.check_header('sys/signalfd.h'),
+  'HAVE_SYS_TIMERFD_H': cc.check_header('sys/timerfd.h'),
+
   'HAVE_ARC4RANDOM': cc.has_function('arc4random'),
-  'HAVE_KEVENT': cc.has_function('kevent', prefix: '#include <sys/event.h>'),
-  'HAVE_PORT_CREATE': cc.has_function('port_create', prefix: '#include <port.h>'),
-  'HAVE_EPOLL_CTL': cc.has_function('epoll_ctl', prefix: '#include <sys/epoll.h>'),
-  'HAVE_TIMERFD_CREATE': cc.has_function('timerfd_create', prefix: '#include <sys/timerfd.h>'),
   'HAVE_DLINFO': cc.has_function('dlinfo', dependencies: dl_dep),
+  'HAVE_EPOLL_CTL': cc.has_function('epoll_ctl', prefix: '#include <sys/epoll.h>'),
+  'HAVE_GETEXECNAME': cc.has_function('getexecname'),
+  'HAVE_KEVENT': cc.has_function('kevent', prefix: '#include <sys/event.h>'),
   'HAVE_NANOSLEEP': cc.has_function('nanosleep', dependencies: rt_dep),
+  'HAVE_PORT_CREATE': cc.has_function('port_create', prefix: '#include <port.h>'),
+  'HAVE_SIGNALFD': cc.has_function('signalfd'),
+  'HAVE_STRCASESTR': cc.has_function('strcasestr'),
+  'HAVE_STRLCAT': cc.has_function('strlcat'),
+  'HAVE_STRLCPY': cc.has_function('strlcpy'),
   'HAVE_TIMER_CREATE': cc.has_function('timer_create', dependencies: rt_dep, prefix: '#include <time.h>'),
+  'HAVE_TIMERFD_CREATE': cc.has_function('timerfd_create', prefix: '#include <sys/timerfd.h>'),
+
   'HAVE_DEVPOLL': fs.exists('/dev/poll'),
-  'SOCKADDR_IN_HAS_LEN': cc.has_member('struct sockaddr', 'sa_len', prefix: '#include <sys/types.h>\n#include <sys/socket.h>'),
+  'RB_SOCKADDR_HAS_SA_LEN': cc.has_member('struct sockaddr', 'sa_len', prefix: '#include <sys/types.h>\n#include <sys/socket.h>'),
 }
 foreach define, found : librb_checks
   if found
@@ -76,6 +78,10 @@ foreach define, found : librb_checks
   endif
 endforeach
 
+if host_machine.endian() == 'big'
+  conf_data.set('WORDS_BIGENDIAN', 1)
+endif
+
 # TLS backend configuration (passed from parent)
 if have_openssl
   librb_conf_data.set('HAVE_OPENSSL', 1)
diff --git a/librb/src/balloc.c b/librb/src/balloc.c
index ada7c475..eeb5964a 100644
--- a/librb/src/balloc.c
+++ b/librb/src/balloc.c
@@ -57,7 +57,7 @@
 #include <librb_config.h>
 #include <rb_lib.h>
 
-static void _rb_bh_fail(const char *reason, const char *file, int line) __attribute__((noreturn));
+static void _rb_bh_fail(const char *reason, const char *file, int line) __noreturn;
 
 static uintptr_t offset_pad;
 
diff --git a/meson.build b/meson.build
index 1bce5085..745f054a 100644
--- a/meson.build
+++ b/meson.build
@@ -153,17 +153,6 @@ if have_hyperscan
   conf_data.set('HAVE_HYPERSCAN', 1)
 endif
 
-# TLS backend defines
-if have_openssl
-  conf_data.set('HAVE_OPENSSL', 1)
-endif
-if have_mbedtls
-  conf_data.set('HAVE_MBEDTLS', 1)
-endif
-if have_gnutls
-  conf_data.set('HAVE_GNUTLS', 1)
-endif
-
 # Performance
 if get_option('profile')
   conf_data.set('SOLANUM_PROFILE', 1)
@@ -189,13 +178,8 @@ conf_data.set('AWAY_HEAP_SIZE', 512)
 
 # System checks
 system_checks = {
-  'HAVE_CRYPT_H': cc.has_header('crypt.h'),
-  'HAVE_SYS_PARAM_H': cc.has_header('sys/param.h'),
-  'HAVE_SYS_SYSLOG_H': cc.has_header('sys/syslog.h'),
-  'HAVE_SYS_EPOLL_H': cc.has_header('sys/epoll.h'),
-  'HAVE_MACHINE_ENDIAN_H': cc.has_header('machine/endian.h'),
-  'HAVE_STRLCAT': cc.has_function('strlcat'),
-  'HAVE_STRLCPY': cc.has_function('strlcpy'),
+  'HAVE_STRINGS_H': cc.check_header('strings.h'),
+  'HAVE_SYS_PARAM_H': cc.check_header('sys/param.h'),
 }
 foreach define, found : system_checks
   if found
@@ -203,10 +187,14 @@ foreach define, found : system_checks
   endif
 endforeach
 
-if not cc.has_header('stdarg.h')
+if not cc.check_header('stdarg.h')
   error('stdarg.h is required')
 endif
 
+if not cc.check_header('stdbool.h')
+  error('stdbool.h is required')
+endif
+
 conf_data.set_quoted('PATH_DEVNULL', '/dev/null')
 
 if cc.has_type('uintptr_t', prefix: '#include <stdint.h>')
diff --git a/tools/mkpasswd.c b/tools/mkpasswd.c
index 85d5d216..1810f819 100644
--- a/tools/mkpasswd.c
+++ b/tools/mkpasswd.c
@@ -39,8 +39,8 @@ static char *make_bf_salt_para(int, char *);
 static char *generate_random_salt(char *, int);
 static char *generate_poor_salt(char *, int);
 
-static void full_usage(void) __attribute__((noreturn));
-static void brief_usage(void) __attribute__((noreturn));
+static void full_usage(void) __noreturn;
+static void brief_usage(void) __noreturn;
 
 static char saltChars[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        /* 0 .. 63, ascii - 64 */