From 345c1b0eeeac333c3da8baa46e9b96c3b2aca443 Mon Sep 17 00:00:00 2001
From: Jason Evans <jasone@canonware.com>
Date: Tue, 15 Sep 2015 14:59:56 -0700
Subject: [PATCH] Link test to librt if it contains clock_gettime(2).

This resolves #257.
---
 Makefile.in  | 7 ++++---
 configure.ac | 9 +++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index a836e749..01285afb 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -28,6 +28,7 @@ CFLAGS := @CFLAGS@
 LDFLAGS := @LDFLAGS@
 EXTRA_LDFLAGS := @EXTRA_LDFLAGS@
 LIBS := @LIBS@
+TESTLIBS := @TESTLIBS@
 RPATH_EXTRA := @RPATH_EXTRA@
 SO := @so@
 IMPORTLIB := @importlib@
@@ -265,15 +266,15 @@ $(STATIC_LIBS):
 
 $(objroot)test/unit/%$(EXE): $(objroot)test/unit/%.$(O) $(TESTS_UNIT_LINK_OBJS) $(C_JET_OBJS) $(C_TESTLIB_UNIT_OBJS)
 	@mkdir -p $(@D)
-	$(CC) $(LDTARGET) $(filter %.$(O),$^) $(call RPATH,$(objroot)lib) $(LDFLAGS) $(filter-out -lm,$(LIBS)) -lm $(EXTRA_LDFLAGS)
+	$(CC) $(LDTARGET) $(filter %.$(O),$^) $(call RPATH,$(objroot)lib) $(LDFLAGS) $(filter-out -lm,$(LIBS)) -lm $(TESTLIBS) $(EXTRA_LDFLAGS)
 
 $(objroot)test/integration/%$(EXE): $(objroot)test/integration/%.$(O) $(C_TESTLIB_INTEGRATION_OBJS) $(C_UTIL_INTEGRATION_OBJS) $(objroot)lib/$(LIBJEMALLOC).$(IMPORTLIB)
 	@mkdir -p $(@D)
-	$(CC) $(LDTARGET) $(filter %.$(O),$^) $(call RPATH,$(objroot)lib) $(objroot)lib/$(LIBJEMALLOC).$(IMPORTLIB) $(LDFLAGS) $(filter-out -lm,$(filter -lpthread,$(LIBS))) -lm $(EXTRA_LDFLAGS)
+	$(CC) $(LDTARGET) $(filter %.$(O),$^) $(call RPATH,$(objroot)lib) $(objroot)lib/$(LIBJEMALLOC).$(IMPORTLIB) $(LDFLAGS) $(filter-out -lm,$(filter -lpthread,$(LIBS))) -lm $(TESTLIBS) $(EXTRA_LDFLAGS)
 
 $(objroot)test/stress/%$(EXE): $(objroot)test/stress/%.$(O) $(C_JET_OBJS) $(C_TESTLIB_STRESS_OBJS) $(objroot)lib/$(LIBJEMALLOC).$(IMPORTLIB)
 	@mkdir -p $(@D)
-	$(CC) $(LDTARGET) $(filter %.$(O),$^) $(call RPATH,$(objroot)lib) $(objroot)lib/$(LIBJEMALLOC).$(IMPORTLIB) $(LDFLAGS) $(filter-out -lm,$(LIBS)) -lm $(EXTRA_LDFLAGS)
+	$(CC) $(LDTARGET) $(filter %.$(O),$^) $(call RPATH,$(objroot)lib) $(objroot)lib/$(LIBJEMALLOC).$(IMPORTLIB) $(LDFLAGS) $(filter-out -lm,$(LIBS)) -lm $(TESTLIBS) $(EXTRA_LDFLAGS)
 
 build_lib_shared: $(DSOS)
 build_lib_static: $(STATIC_LIBS)
diff --git a/configure.ac b/configure.ac
index 2308b990..7a1290e0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1190,6 +1190,14 @@ fi
 
 CPPFLAGS="$CPPFLAGS -D_REENTRANT"
 
+dnl Check whether clock_gettime(2) is in libc or librt.  This function is only
+dnl used in test code, so save the result to TESTLIBS to avoid poluting LIBS.
+SAVED_LIBS="${LIBS}"
+LIBS=
+AC_SEARCH_LIBS([clock_gettime], [rt], [TESTLIBS="${LIBS}"])
+AC_SUBST([TESTLIBS])
+LIBS="${SAVED_LIBS}"
+
 dnl Check if the GNU-specific secure_getenv function exists.
 AC_CHECK_FUNC([secure_getenv],
               [have_secure_getenv="1"],
@@ -1694,6 +1702,7 @@ AC_MSG_RESULT([CPPFLAGS           : ${CPPFLAGS}])
 AC_MSG_RESULT([LDFLAGS            : ${LDFLAGS}])
 AC_MSG_RESULT([EXTRA_LDFLAGS      : ${EXTRA_LDFLAGS}])
 AC_MSG_RESULT([LIBS               : ${LIBS}])
+AC_MSG_RESULT([TESTLIBS           : ${TESTLIBS}])
 AC_MSG_RESULT([RPATH_EXTRA        : ${RPATH_EXTRA}])
 AC_MSG_RESULT([])
 AC_MSG_RESULT([XSLTPROC           : ${XSLTPROC}])