Add optional support to link against tcmalloc.

Just do --enable-tcmalloc at ./configure. You need a system-wide
installation such that
  -ltcmalloc
works without further -L.

Makefile.am

@@ -140,6 +140,7 @@ AM_LDFLAGS = \
 ################################################################################
 
 LIBS = \
+	@TCMALLOC_LIBS@ \
 	@RT_LIBS@ \
 	@LIBEV_LIBS@ \
 	@MATH_LIBS@ \

config/config.h.in

@@ -15,9 +15,15 @@
 /* define if the compiler supports basic C++11 syntax */
 #undef HAVE_CXX11
 
+/* Define to 1 if you have the `futimes' function. */
+#undef HAVE_FUTIMES
+
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
+/* Define to 1 if you have the `tcmalloc' library (-ltcmalloc). */
+#undef HAVE_LIBTCMALLOC
+
 /* Define to 1 if you have the <memory.h> header file. */
 #undef HAVE_MEMORY_H
 

configure.ac

@@ -114,6 +114,25 @@ if test "x$tr_INTERNAL_GO" = "xno"; then
   fi
 fi
 
+dnl ----------------------------------------------------------------------------
+dnl tcmalloc
+dnl ----------------------------------------------------------------------------
+
+AC_ARG_ENABLE(tcmalloc,
+  AS_HELP_STRING([--enable-tcmalloc], [use system-installed tcmalloc library (default: no)]),
+  [tr_TCMALLOC="${enableval:-yes}"],
+  [tr_TCMALLOC=no]
+)
+
+AM_CONDITIONAL(ENABLE_TCMALLOC, test "x$tr_TCMALLOC" = xyes)
+
+if test "x$tr_TCMALLOC" = "xyes"; then
+  TCMALLOC_LIBS="-ltcmalloc"
+else
+  TCMALLOC_LIBS=""
+fi
+AC_SUBST(TCMALLOC_LIBS)
+
 dnl ============================================================================
 dnl --SECTION--                                                          OPTIONS
 dnl ============================================================================