document mingw linker fix and close associated bug

[debian/gzip] / m4 / lock.m4

diff --git a/m4/lock.m4 b/m4/lock.m4
index c0a620600ae2865b222944705b483af363578a47..dac4c383f14ad38641c9ec8552993684bae46239 100644 (file)
--- a/m4/lock.m4
+++ b/m4/lock.m4
@@ -1,5 +1,5 @@
-# lock.m4 serial 11 (gettext-0.18.2)
-dnl Copyright (C) 2005-2012 Free Software Foundation, Inc.
+# lock.m4 serial 14
+dnl Copyright (C) 2005-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -10,13 +10,18 @@ AC_DEFUN([gl_LOCK],
 [
   AC_REQUIRE([gl_THREADLIB])
   if test "$gl_threads_api" = posix; then
-    # OSF/1 4.0 and MacOS X 10.1 lack the pthread_rwlock_t type and the
+    # OSF/1 4.0 and Mac OS X 10.1 lack the pthread_rwlock_t type and the
     # pthread_rwlock_* functions.
+    has_rwlock=false
     AC_CHECK_TYPE([pthread_rwlock_t],
-      [AC_DEFINE([HAVE_PTHREAD_RWLOCK], [1],
+      [has_rwlock=true
+       AC_DEFINE([HAVE_PTHREAD_RWLOCK], [1],
          [Define if the POSIX multithreading library has read/write locks.])],
       [],
       [#include <pthread.h>])
+    if $has_rwlock; then
+      gl_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER
+    fi
     # glibc defines PTHREAD_MUTEX_RECURSIVE as enum, not as a macro.
     AC_COMPILE_IFELSE([
       AC_LANG_PROGRAM(
@@ -24,6 +29,9 @@ AC_DEFUN([gl_LOCK],
         [[
 #if __FreeBSD__ == 4
 error "No, in FreeBSD 4.0 recursive mutexes actually don't work."
+#elif (defined __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ \
+       && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070)
+error "No, in Mac OS X < 10.7 recursive mutexes actually don't work."
 #else
 int x = (int)PTHREAD_MUTEX_RECURSIVE;
 return !x;
@@ -35,7 +43,5 @@ return !x;
   gl_PREREQ_LOCK
 ])
 
-# Prerequisites of lib/lock.c.
-AC_DEFUN([gl_PREREQ_LOCK], [
-  AC_REQUIRE([AC_C_INLINE])
-])
+# Prerequisites of lib/glthread/lock.c.
+AC_DEFUN([gl_PREREQ_LOCK], [:])