From 54b8977c2f854d04f9c6383e2cac76ea4cde3eaa Mon Sep 17 00:00:00 2001
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Date: Mon, 29 Dec 2014 12:23:41 +0100
Subject: [PATCH] Link mcaptest with -lrt when needed

The mcaptest tool uses the profiles/health/mcap.c source file, which
calls clock_getres(). This function is defined in librt in some C
libraries, so mcaptest should be linked against librt when needed,
otherwise one gets link failures such as:

ld: profiles/health/mcap.o: undefined reference to symbol 'clock_getres@@GLIBC_2.2.5'
ld: note: 'clock_getres@@GLIBC_2.2.5' is defined in DSO [...]/sysroot/lib64/librt.so.1 so try adding it to the linker command line
[...]/sysroot/lib64/librt.so.1: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status
Makefile:4184: recipe for target 'tools/mcaptest' failed

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 Makefile.tools | 2 +-
 configure.ac   | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Makefile.tools b/Makefile.tools
index bc827fe..fef3db5 100644
--- a/Makefile.tools
+++ b/Makefile.tools
@@ -195,7 +195,7 @@ tools_mcaptest_SOURCES = tools/mcaptest.c \
 				btio/btio.h btio/btio.c \
 				src/log.c src/log.h \
 				profiles/health/mcap.h profiles/health/mcap.c
-tools_mcaptest_LDADD = lib/libbluetooth-internal.la @GLIB_LIBS@
+tools_mcaptest_LDADD = lib/libbluetooth-internal.la @GLIB_LIBS@ @RT_LIBS@
 
 dist_man_MANS += tools/hciattach.1 tools/hciconfig.1 \
 			tools/hcitool.1 tools/hcidump.1 \
diff --git a/configure.ac b/configure.ac
index 4739c10..b0afba6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -54,6 +54,11 @@ AC_CHECK_LIB(pthread, pthread_create, dummy=yes,
 AC_CHECK_LIB(dl, dlopen, dummy=yes,
 			AC_MSG_ERROR(dynamic linking loader is required))
 
+AC_SEARCH_LIBS([clock_getres], [rt],
+			[test "$ac_cv_search_clock_getres" = "none required" ||
+			RT_LIBS=$ac_cv_search_clock_getres])
+AC_SUBST([RT_LIBS])
+
 PKG_CHECK_MODULES(GLIB, glib-2.0 >= 2.28, dummy=yes,
 				AC_MSG_ERROR(GLib >= 2.28 is required))
 AC_SUBST(GLIB_CFLAGS)
-- 
2.1.0