From 285eb31812bc7c2c48a8b1bbe14e01084ba92b05 Mon Sep 17 00:00:00 2001
From: D Herring <dherring@at.tentpost.dot.com>
Date: Fri, 20 Dec 2013 01:15:59 -0500
Subject: [PATCH] fixes for the detection of GC_start_call_back

- HAVE_GC_SET_START_CALLBACK was defined unconditionally
- there was no AC_DEFINE if system_boehm was false
- there was a typo in one usage site of this macro

see 6b754564f1d1a2d320b1fd46f0c0da2e623862c1
---
 src/aclocal.m4    | 2 ++
 src/c/alloc_2.d   | 2 +-
 src/configure     | 3 +++
 src/h/config.h.in | 2 +-
 4 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/aclocal.m4 b/src/aclocal.m4
index 19c411549..d49321a31 100644
--- a/src/aclocal.m4
+++ b/src/aclocal.m4
@@ -948,6 +948,8 @@ if test "${enable_boehm}" = auto -o "${enable_boehm}" = system; then
  if test "${system_boehm}" = "yes"; then
    AC_CHECK_LIB( [gc], [GC_set_start_callback],
                  [AC_DEFINE(HAVE_GC_SET_START_CALLBACK)], [] )
+ else
+  AC_DEFINE(HAVE_GC_SET_START_CALLBACK)
  fi
  AC_MSG_CHECKING( [whether we can use the existing Boehm-Weiser library] )
  AC_MSG_RESULT( [${system_boehm}] )
diff --git a/src/c/alloc_2.d b/src/c/alloc_2.d
index 75e70808b..51366fd3a 100644
--- a/src/c/alloc_2.d
+++ b/src/c/alloc_2.d
@@ -32,7 +32,7 @@
 #ifdef GBC_BOEHM
 
 static void (*GC_old_start_callback)(void) = NULL;
-#ifdef HAVE_GC_START_CALLBACK
+#ifdef HAVE_GC_SET_START_CALLBACK
 extern void GC_set_start_callback(void *);
 extern void *GC_get_start_callback(void *);
 #else
diff --git a/src/configure b/src/configure
index 999231a32..159f82ffe 100755
--- a/src/configure
+++ b/src/configure
@@ -5970,6 +5970,9 @@ if test "x$ac_cv_lib_gc_GC_set_start_callback" = xyes; then :
 
 fi
 
+ else
+  $as_echo "#define HAVE_GC_SET_START_CALLBACK 1" >>confdefs.h
+
  fi
  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we can use the existing Boehm-Weiser library " >&5
 $as_echo_n "checking whether we can use the existing Boehm-Weiser library ... " >&6; }
diff --git a/src/h/config.h.in b/src/h/config.h.in
index f6b6b8daf..169049e54 100644
--- a/src/h/config.h.in
+++ b/src/h/config.h.in
@@ -309,7 +309,7 @@ typedef unsigned char ecl_base_char;
 #endif
 
 /* GC_set_start_callback						*/
-#define HAVE_GC_SET_START_CALLBACK
+#undef HAVE_GC_SET_START_CALLBACK
 
 /*
  * SYSTEM FEATURES: