From: Andreas Schneider <asn@samba.org>
Date: Mon, 23 Sep 2019 13:14:24 +0000 (+0200)
Subject: replace: Only link against librt if really needed
X-Git-Tag: talloc-2.3.1~676
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=480152dd6729d4c58faca6f3e4fa91ff4614c272;p=thirdparty%2Fsamba.git

replace: Only link against librt if really needed

fdatasync() and clock_gettime() are provided by glibc on Linux, so there
is no need to link against librt. Checks have been added so if there are
platforms which require it are still functional.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14140

Signed-off-by: Andreas Schneider <asn@samba.org>
Signed-off-by: Isaac Boukris <iboukris@gmail.com>
Pair-Programmed-With: Isaac Boukris <iboukris@gmail.com>
Reviewed-by: Matthias Dieter Wallnöfer <mdw@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>
---

diff --git a/lib/replace/wscript b/lib/replace/wscript
index c22262191c2..5b5a9ab39c0 100644
--- a/lib/replace/wscript
+++ b/lib/replace/wscript
@@ -459,11 +459,28 @@ def configure(conf):
     conf.CHECK_C_PROTOTYPE('dlopen', 'void *dlopen(const char* filename, unsigned int flags)',
                            define='DLOPEN_TAKES_UNSIGNED_FLAGS', headers='dlfcn.h dl.h')
 
-    if conf.CHECK_FUNCS_IN('fdatasync', 'rt', checklibc=True):
+    #
+    # Check for clock_gettime and fdatasync
+    #
+    # First check libc to avoid linking libreplace against librt.
+    #
+    if conf.CHECK_FUNCS('fdatasync'):
         # some systems are missing the declaration
         conf.CHECK_DECLS('fdatasync')
+    else:
+        if conf.CHECK_FUNCS_IN('fdatasync', 'rt'):
+            # some systems are missing the declaration
+            conf.CHECK_DECLS('fdatasync')
+
+    has_clock_gettime = False
+    if conf.CHECK_FUNCS('clock_gettime'):
+        has_clock_gettime = True
+
+    if not has_clock_gettime:
+        if conf.CHECK_FUNCS_IN('clock_gettime', 'rt', checklibc=True):
+            has_clock_gettime = True
 
-    if conf.CHECK_FUNCS_IN('clock_gettime', 'rt', checklibc=True):
+    if has_clock_gettime:
         for c in ['CLOCK_MONOTONIC', 'CLOCK_PROCESS_CPUTIME_ID', 'CLOCK_REALTIME']:
             conf.CHECK_CODE('''
                 #if TIME_WITH_SYS_TIME
@@ -817,6 +834,7 @@ def build(bld):
 
     extra_libs = ''
     if bld.CONFIG_SET('HAVE_LIBBSD'): extra_libs += ' bsd'
+    if bld.CONFIG_SET('HAVE_LIBRT'): extra_libs += ' rt'
 
     bld.SAMBA_SUBSYSTEM('LIBREPLACE_HOSTCC',
         REPLACE_HOSTCC_SOURCE,
@@ -856,7 +874,7 @@ def build(bld):
                       # at the moment:
                       # hide_symbols=bld.BUILTIN_LIBRARY('replace'),
                       private_library=True,
-                      deps='crypt dl nsl socket rt attr' + extra_libs)
+                      deps='crypt dl nsl socket attr' + extra_libs)
 
     replace_test_cflags = ''
     if bld.CONFIG_SET('HAVE_WNO_FORMAT_TRUNCATION'):