Lower the required glib version to 2.8 for static builds

Makefile.static-build

@@ -8,6 +8,10 @@ MSGPACK_LIB=ext/lib/libmsgpack.a
 
 TMATE_CONFIGURE=PKG_CONFIG_PATH=./ext/lib/pkgconfig
 
+LIBC=$(shell gcc -print-file-name=libc.a)
+STATIC_LIBC_OBJECTS=fdelt_chk
+STATIC_COMPAT_OBJECTS=memcpy clock_gettime
+
 all: tmate
 
 dependencies:
@@ -39,11 +43,18 @@ $(MSGPACK_LIB): $(MSGPACK)/.ready
 	cd $(MSGPACK)/build; ([ -f Makefile ] || cmake -DCMAKE_INSTALL_PREFIX:PATH=$(shell pwd)/ext ..)
 	+make -C $(MSGPACK)/build install
 
-tmate: $(MSGPACK_LIB) $(LIBSSH_LIB)
+libc/%.o:
+	mkdir -p libc
+	cd libc; ar x $(LIBC) $(notdir $@)
+
+compat/%.o: compat/%.c
+	gcc -c -o $@ $<
+
+tmate: $(MSGPACK_LIB) $(LIBSSH_LIB) $(patsubst %,libc/%.o,$(STATIC_LIBC_OBJECTS)) $(patsubst %,compat/%.o,$(STATIC_COMPAT_OBJECTS))
 	./autogen.sh
 	$(TMATE_CONFIGURE) ./configure --enable-static
 	+make
 
 clean:
-	rm -rf ext $(LIBSSH) $(MSGPACK)
+	rm -rf ext libc $(LIBSSH) $(MSGPACK)
 	+make clean

compat/clock_gettime.c

@@ -0,0 +1,9 @@
+#define _GNU_SOURCE
+#include <time.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+int clock_gettime(clockid_t clk_id, struct timespec *tp)
+{
+	return syscall(SYS_clock_gettime, clk_id, tp);
+}

compat/memcpy.c

@@ -0,0 +1,11 @@
+// http://stackoverflow.com/questions/8823267/linking-against-older-symbol-version-in-a-so-file
+
+#include <string.h>
+
+/* some systems do not have newest memcpy@@GLIBC_2.14 - stay with old good one */
+asm (".symver memcpy, memcpy@GLIBC_2.2.5");
+
+void *__wrap_memcpy(void *dest, const void *src, size_t n)
+{
+    return memcpy(dest, src, n);
+}

configure.ac

@@ -61,6 +61,7 @@ if test "x$found_static" = xyes; then
 		CPPFLAGS="$LIBCRYPTO_CFLAGS $CPPFLAGS"
 		LIBS="$LIBCRYPTO_LIBS $LIBS"
 	])
+  # See more static settings below... (search for found_static)
 fi
 
 # Is this gcc?
@@ -451,6 +452,12 @@ AM_CONDITIONAL(NO_GETOPT, [test "x$found_getopt" = xno])
 
 if test "x$found_static" = xyes; then
 	# libc and libdl should be dynamically linked.
+	# but we want to lower our requirements for libc's version.
+	# so we extract some symobls and add them here
+	if test `uname -m` = x86_64; then
+		LIBS="compat/memcpy.o -Wl,--wrap=memcpy $LIBS"
+	fi
+	LIBS="compat/clock_gettime.o libc/fdelt_chk.o $LIBS"
 	LIBS="-Wl,-Bstatic ${LIBS/-ldl/} -Wl,-Bdynamic -ldl"
 fi