From: Dave Hart <hart@ntp.org>
Date: Sun, 13 Feb 2011 06:50:40 +0000 (-0500)
Subject: Use the gcc -ffunction-segments feature to allow gc when linking with static libevent
X-Git-Tag: release-2.0.11-stable~51
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0965c563568e49448955aea30bd43df30e544b92;p=libevent

Use the gcc -ffunction-segments feature to allow gc when linking with static libevent
---

diff --git a/configure.in b/configure.in
index 53701368..c00abd20 100644
--- a/configure.in
+++ b/configure.in
@@ -628,5 +628,37 @@ if test x$enable_gcc_warnings = xyes && test "$GCC" = "yes"; then
 
 fi
 
+LIBEVENT_GC_SECTIONS=
+if test "$GCC" = yes ; then
+    AC_CACHE_CHECK(
+	[if linker supports omitting unused code and data],
+	[libevent_cv_gc_sections_works],
+	[
+	    origCFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS -Wl,--gc-sections"
+	    AC_LINK_IFELSE(
+		[AC_LANG_PROGRAM([[]], [[]])],
+		[
+		    if grep gc-sections conftest.err ; then
+			libevent_cv_gc_sections_works=no
+		    else
+			libevent_cv_gc_sections_works=yes
+		    fi
+		],
+		[libevent_cv_gc_sections_works=no]
+	    )
+	    CFLAGS="$origCFLAGS"
+	    AS_UNSET([origCFLAGS])
+	]
+    )
+    case "$libevent_cv_gc_sections_works" in
+     yes)
+	CFLAGS="-ffunction-sections -fdata-sections $CFLAGS"
+	LIBEVENT_GC_SECTIONS="-Wl,--gc-sections"
+	;;
+    esac
+fi
+AC_SUBST([LIBEVENT_GC_SECTIONS])
+
 AC_CONFIG_FILES( [libevent.pc libevent_openssl.pc libevent_pthreads.pc] )
 AC_OUTPUT(Makefile include/Makefile test/Makefile sample/Makefile)
diff --git a/sample/Makefile.am b/sample/Makefile.am
index 0071d26f..2d616f9e 100644
--- a/sample/Makefile.am
+++ b/sample/Makefile.am
@@ -1,6 +1,6 @@
 AUTOMAKE_OPTIONS = foreign no-dependencies
 
-LDADD = ../libevent.la
+LDADD = @LIBEVENT_GC_SECTIONS@ ../libevent.la
 AM_CFLAGS = -I$(top_srcdir) -I$(top_srcdir)/compat -I$(top_srcdir)/include -I../include
 
 noinst_PROGRAMS = event-test time-test signal-test dns-example hello-world http-server
diff --git a/test/Makefile.am b/test/Makefile.am
index 97682fb4..b9fb8d04 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -45,7 +45,7 @@ if BUILD_WIN32
 regress_SOURCES += regress_iocp.c
 endif
 
-regress_LDADD = ../libevent.la $(PTHREAD_LIBS) $(ZLIB_LIBS)
+regress_LDADD = @LIBEVENT_GC_SECTIONS@ ../libevent.la $(PTHREAD_LIBS) $(ZLIB_LIBS)
 regress_CFLAGS = -I$(top_srcdir) -I$(top_srcdir)/compat \
 	-I$(top_srcdir)/include -I../include $(PTHREAD_CFLAGS) $(ZLIB_CFLAGS)
 regress_LDFLAGS = $(PTHREAD_CFLAGS)
@@ -56,13 +56,13 @@ regress_LDADD += ../libevent_openssl.la -lcrypto -lssl
 endif
 
 bench_SOURCES = bench.c
-bench_LDADD = ../libevent.la
+bench_LDADD = @LIBEVENT_GC_SECTIONS@ ../libevent.la
 bench_cascade_SOURCES = bench_cascade.c
-bench_cascade_LDADD = ../libevent.la
+bench_cascade_LDADD = @LIBEVENT_GC_SECTIONS@ ../libevent.la
 bench_http_SOURCES = bench_http.c
-bench_http_LDADD = ../libevent.la
+bench_http_LDADD = @LIBEVENT_GC_SECTIONS@ ../libevent.la
 bench_httpclient_SOURCES = bench_httpclient.c
-bench_httpclient_LDADD = ../libevent_core.la
+bench_httpclient_LDADD = @LIBEVENT_GC_SECTIONS@ ../libevent_core.la
 
 regress.gen.c regress.gen.h: regress.rpc $(top_srcdir)/event_rpcgen.py
 	$(top_srcdir)/event_rpcgen.py $(srcdir)/regress.rpc || echo "No Python installed"