From 664ef652d970e14a4c941bf650cb50dbb4128b05 Mon Sep 17 00:00:00 2001
From: Jason Evans <jasone@canonware.com>
Date: Sat, 18 Feb 2017 00:02:23 -0800
Subject: [PATCH] Avoid -lgcc for heap profiling if unwind.h is missing.

This removes an unneeded library dependency when falling back to
intrinsics-based backtracing (or failing to enable heap profiling at
all).
---
 configure.ac | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index e71edd72..1627a3d9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1082,7 +1082,9 @@ fi
 if test "x$backtrace_method" = "x" -a "x$enable_prof_libgcc" = "x1" \
      -a "x$GCC" = "xyes" ; then
   AC_CHECK_HEADERS([unwind.h], , [enable_prof_libgcc="0"])
-  AC_CHECK_LIB([gcc], [_Unwind_Backtrace], [JE_APPEND_VS(LIBS, -lgcc)], [enable_prof_libgcc="0"])
+  if test "x${enable_prof_libgcc}" = "x1" ; then
+    AC_CHECK_LIB([gcc], [_Unwind_Backtrace], [JE_APPEND_VS(LIBS, -lgcc)], [enable_prof_libgcc="0"])
+  fi
   if test "x${enable_prof_libgcc}" = "x1" ; then
     backtrace_method="libgcc"
     AC_DEFINE([JEMALLOC_PROF_LIBGCC], [ ])