Use libbacktrace to generate better leak callstacks.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@3986 ed5197a5-7fde-0310-b194-c3ffbd925b24

deps/libbacktrace/config/unwind_ipinfo.m4

@@ -0,0 +1,37 @@
+dnl
+dnl Check whether _Unwind_GetIPInfo is available without doing a link
+dnl test so we can use this with libstdc++-v3 and libjava.  Need to
+dnl use $target to set defaults because automatic checking is not possible
+dnl without a link test (and maybe even with a link test).
+dnl
+
+AC_DEFUN([GCC_CHECK_UNWIND_GETIPINFO], [
+  AC_ARG_WITH(system-libunwind,
+  [  --with-system-libunwind use installed libunwind])
+  # If system-libunwind was not specifically set, pick a default setting.
+  if test x$with_system_libunwind = x; then
+    case ${target} in
+      ia64-*-hpux*) with_system_libunwind=yes ;;
+      *) with_system_libunwind=no ;;
+    esac
+  fi
+  # Based on system-libunwind and target, do we have ipinfo?
+  if  test x$with_system_libunwind = xyes; then
+    case ${target} in
+      ia64-*-*) have_unwind_getipinfo=no ;;
+      *) have_unwind_getipinfo=yes ;;
+    esac
+  else
+    # Darwin before version 9 does not have _Unwind_GetIPInfo.
+    changequote(,)
+    case ${target} in
+      *-*-darwin[3-8]|*-*-darwin[3-8].*) have_unwind_getipinfo=no ;;
+      *) have_unwind_getipinfo=yes ;;
+    esac
+    changequote([,])
+  fi
+
+  if test x$have_unwind_getipinfo = xyes; then
+    AC_DEFINE(HAVE_GETIPINFO, 1, [Define if _Unwind_GetIPInfo is available.])
+  fi
+])