From 90e4592b1746d9ce34e9e32133ebab359cfa4276 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Fri, 10 Feb 2017 11:28:01 +0100
Subject: build: add m4 macros for --enable-lto and --enable-ld-gc

---
 m4/compiler_options.m4 | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'm4')

diff --git a/m4/compiler_options.m4 b/m4/compiler_options.m4
index c998711d7..fa35b9168 100644
--- a/m4/compiler_options.m4
+++ b/m4/compiler_options.m4
@@ -124,3 +124,30 @@ else
 	AC_MSG_RESULT(no)
 fi
 ])
+
+AC_DEFUN([NM_LTO],
+[AC_ARG_ENABLE(lto, AS_HELP_STRING([--enable-lto], [Enable Link Time Optimization for smaller size (default: no)]))
+if (test "${enable_lto}" = "yes"); then
+    CFLAGS="-flto $CFLAGS"
+else
+    enable_lto='no'
+fi
+])
+
+AC_DEFUN([NM_LD_GC],
+[AC_ARG_ENABLE(ld-gc, AS_HELP_STRING([--enable-ld-gc], [Enable garbage collection of unused symbols on linking (default: auto)]))
+if (test "${enable_ld_gc}" != "no"); then
+	CC_CHECK_FLAG_APPEND([ld_gc_flags], [CFLAGS], [-fdata-sections -ffunction-sections -Wl,--gc-sections])
+	if (test -n "${ld_gc_flags}"); then
+		enable_ld_gc="yes"
+		CFLAGS="$CFLAGS $ld_gc_flags"
+	else
+		if (test "${enable_ld_gc}" = "yes"); then
+			AC_MSG_ERROR([Unused symbol eviction requested but not supported.])
+		else
+			enable_ld_gc="no"
+		fi
+	fi
+fi
+])
+
-- 
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