Makefile.def: Remove reference to boehm-gc target module.

<toplevel>

2016-11-30  Matthias Klose  <doko@ubuntu.com>

        * Makefile.def: Remove reference to boehm-gc target module.
        * configure.ac: Include pkg.m4, check for --with-target-bdw-gc
        options and for the bdw-gc pkg-config module.
        * configure: Regenerate.
        * Makefile.in: Regenerate.

gcc/

2016-11-30  Matthias Klose  <doko@ubuntu.com>

        * doc/install.texi: Document configure options --enable-objc-gc
        and --with-target-bdw-gc.

config/

2016-11-30  Matthias Klose  <doko@ubuntu.com>

        * pkg.m4: New file.

libobjc/

2016-11-30  Matthias Klose  <doko@ubuntu.com>

        * configure.ac (--enable-objc-gc): Allow to configure with a
        system provided boehm-gc.
        * configure: Regenerate.
        * Makefile.in (OBJC_BOEHM_GC_LIBS): Get value from configure.
        * gc.c: Include system bdw-gc headers.
        * memory.c: Likewise
        * objects.c: Likewise

boehm-gc/

2016-11-30  Matthias Klose  <doko@ubuntu.com>

        Remove

From-SVN: r242985

7 files changed, 526 insertions, 59 deletions

diff --git a/libobjc/ChangeLog b/libobjc/ChangeLog
index 042d076cf2a..d38ac75e950 100644
--- a/libobjc/ChangeLog
+++ b/libobjc/ChangeLog
@@ -1,3 +1,13 @@
+2016-11-30  Matthias Klose  <doko@ubuntu.com>
+
+	* configure.ac (--enable-objc-gc): Allow to configure with a
+	system provided boehm-gc.
+	* configure: Regenerate.
+	* Makefile.in (OBJC_BOEHM_GC_LIBS): Get value from configure.
+	* gc.c: Include system bdw-gc headers.
+	* memory.c: Likewise
+	* objects.c: Likewise
+
 2016-11-15  Matthias Klose  <doko@ubuntu.com>
 
 	* aclocal.m4: Regenerate.
diff --git a/libobjc/Makefile.in b/libobjc/Makefile.in
index b61823c5827..3329a5cb3fb 100644
--- a/libobjc/Makefile.in
+++ b/libobjc/Makefile.in
@@ -47,8 +47,6 @@ extra_ldflags_libobjc = @extra_ldflags_libobjc@
 
 top_builddir = .
 
--include ../boehm-gc/threads.mk
-
 libdir = $(exec_prefix)/lib
 libsubdir = $(libdir)/gcc/$(target_noncanonical)/$(gcc_version)
 
@@ -95,7 +93,7 @@ LIBTOOL_CLEAN   = $(LIBTOOL) --mode=clean
 OBJC_GCFLAGS=@OBJC_GCFLAGS@
 OBJC_BOEHM_GC=@OBJC_BOEHM_GC@
 OBJC_BOEHM_GC_INCLUDES=@OBJC_BOEHM_GC_INCLUDES@
-OBJC_BOEHM_GC_LIBS=../boehm-gc/libgcjgc_convenience.la $(thread_libs_and_flags)
+OBJC_BOEHM_GC_LIBS=@OBJC_BOEHM_GC_LIBS@
 
 INCLUDES = -I$(srcdir)/$(MULTISRCTOP)../gcc \
   -I$(srcdir)/$(MULTISRCTOP)../gcc/config \
diff --git a/libobjc/configure b/libobjc/configure
index b692eedeff7..43a68de9977 100755
--- a/libobjc/configure
+++ b/libobjc/configure
@@ -600,6 +600,13 @@ ac_includes_default="\
 
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
+OBJC_BOEHM_GC_LIBS
+OBJC_BOEHM_GC_INCLUDES
+OBJC_BOEHM_GC
+OBJC_GCFLAGS
+PKG_CONFIG_LIBDIR
+PKG_CONFIG_PATH
+PKG_CONFIG
 SET_MAKE
 CPP
 OTOOL64
@@ -654,9 +661,6 @@ host_vendor
 host_cpu
 host
 multi_basedir
-OBJC_BOEHM_GC_INCLUDES
-OBJC_BOEHM_GC
-OBJC_GCFLAGS
 VERSION
 target_subdir
 host_subdir
@@ -711,7 +715,6 @@ with_build_libsubdir
 with_target_subdir
 with_cross_host
 enable_version_specific_runtime_libs
-enable_objc_gc
 enable_multilib
 enable_maintainer_mode
 enable_shared
@@ -721,12 +724,19 @@ enable_fast_install
 with_gnu_ld
 enable_libtool_lock
 enable_tls
+enable_objc_gc
+with_target_bdw_gc
+with_target_bdw_gc_include
+with_target_bdw_gc_lib
 '
       ac_precious_vars='build_alias
 host_alias
 target_alias
 CPP
-CPPFLAGS'
+CPPFLAGS
+PKG_CONFIG
+PKG_CONFIG_PATH
+PKG_CONFIG_LIBDIR'
 
 
 # Initialize some variables set by options.
@@ -1343,8 +1353,6 @@ Optional Features:
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --enable-version-specific-runtime-libs    Specify that runtime libraries should be installed in a compiler-specific directory
-  --enable-objc-gc       enable the use of Boehm's garbage collector with
-                          the GNU Objective-C runtime.
   --enable-multilib       build many library versions (default)
   --enable-maintainer-mode  enable make rules and dependencies not useful
 			  (and sometimes confusing) to the casual installer
@@ -1354,6 +1362,8 @@ Optional Features:
                           optimize for fast installation [default=yes]
   --disable-libtool-lock  avoid locking (might break parallel builds)
   --enable-tls            Use thread-local storage [default=yes]
+  --enable-objc-gc        enable use of Boehm's garbage collector with the GNU
+                          Objective-C runtime
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -1365,6 +1375,16 @@ Optional Packages:
   --with-pic              try to use only PIC/non-PIC objects [default=use
                           both]
   --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
+  --with-target-bdw-gc=PATHLIST
+                          specify prefix directory for installed bdw-gc
+                          package. Equivalent to
+                          --with-target-bdw-gc-include=PATH/include plus
+                          --with-target-bdw-gc-lib=PATH/lib
+  --with-target-bdw-gc-include=PATHLIST
+                          specify directories for installed bdw-gc include
+                          files
+  --with-target-bdw-gc-lib=PATHLIST
+                          specify directories for installed bdw-gc library
 
 Some influential environment variables:
   CC          C compiler command
@@ -1375,6 +1395,11 @@ Some influential environment variables:
   CPPFLAGS    C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
   CPP         C preprocessor
+  PKG_CONFIG  path to pkg-config utility
+  PKG_CONFIG_PATH
+              directories to add to pkg-config's search path
+  PKG_CONFIG_LIBDIR
+              path overriding pkg-config's built-in search path
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -2314,28 +2339,6 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $version_specific_libs" >&5
 $as_echo "$version_specific_libs" >&6; }
 
-# Check whether --enable-objc-gc was given.
-if test "${enable_objc_gc+set}" = set; then :
-  enableval=$enable_objc_gc; case $enable_objc_gc in
-  no)
-    OBJC_GCFLAGS=''
-    OBJC_BOEHM_GC=''
-    OBJC_BOEHM_GC_INCLUDES=''
-    ;;
-  *)
-    OBJC_GCFLAGS='-DOBJC_WITH_GC=1'
-    OBJC_BOEHM_GC='libobjc_gc$(libsuffix).la'
-    OBJC_BOEHM_GC_INCLUDES='-I$(top_srcdir)/../boehm-gc/include -I../boehm-gc/include'
-    ;;
-esac
-else
-  OBJC_GCFLAGS=''; OBJC_BOEHM_GC=''; OBJC_BOEHM_GC_INCLUDES=''
-fi
-
-
-
-
-
 # -----------
 # Directories
 # -----------
@@ -10598,7 +10601,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10601 "configure"
+#line 10604 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10704,7 +10707,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10707 "configure"
+#line 10710 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11499,6 +11502,326 @@ $as_echo "#define HAVE_BITFIELD_TYPE_MATTERS 1" >>confdefs.h
   fi
 
 
+# -----------
+# boehm-gc
+# -----------
+
+# Check whether --enable-objc-gc was given.
+if test "${enable_objc_gc+set}" = set; then :
+  enableval=$enable_objc_gc;
+fi
+
+
+# Check whether --with-target-bdw-gc was given.
+if test "${with_target_bdw_gc+set}" = set; then :
+  withval=$with_target_bdw_gc;
+fi
+
+
+# Check whether --with-target-bdw-gc-include was given.
+if test "${with_target_bdw_gc_include+set}" = set; then :
+  withval=$with_target_bdw_gc_include;
+fi
+
+
+# Check whether --with-target-bdw-gc-lib was given.
+if test "${with_target_bdw_gc_lib+set}" = set; then :
+  withval=$with_target_bdw_gc_lib;
+fi
+
+
+case "$enable_objc_gc" in
+no)
+  use_bdw_gc=no
+  ;;
+*)
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for bdw garbage collector" >&5
+$as_echo_n "checking for bdw garbage collector... " >&6; }
+  if test "x$with_target_bdw_gc$with_target_bdw_gc_include$with_target_bdw_gc_lib" = x; then
+
+
+
+
+
+
+
+if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
+	if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
+set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if test "${ac_cv_path_PKG_CONFIG+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+PKG_CONFIG=$ac_cv_path_PKG_CONFIG
+if test -n "$PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PKG_CONFIG" >&5
+$as_echo "$PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_path_PKG_CONFIG"; then
+  ac_pt_PKG_CONFIG=$PKG_CONFIG
+  # Extract the first word of "pkg-config", so it can be a program name with args.
+set dummy pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if test "${ac_cv_path_ac_pt_PKG_CONFIG+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $ac_pt_PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_ac_pt_PKG_CONFIG="$ac_pt_PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_path_ac_pt_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+ac_pt_PKG_CONFIG=$ac_cv_path_ac_pt_PKG_CONFIG
+if test -n "$ac_pt_PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_pt_PKG_CONFIG" >&5
+$as_echo "$ac_pt_PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_pt_PKG_CONFIG" = x; then
+    PKG_CONFIG=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    PKG_CONFIG=$ac_pt_PKG_CONFIG
+  fi
+else
+  PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
+fi
+
+fi
+if test -n "$PKG_CONFIG"; then
+	_pkg_min_version=0.9.0
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking pkg-config is at least version $_pkg_min_version" >&5
+$as_echo_n "checking pkg-config is at least version $_pkg_min_version... " >&6; }
+	if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+	else
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+		PKG_CONFIG=""
+	fi
+fi
+if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"bdw-gc\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "bdw-gc") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: using bdw-gc pkg-config module" >&5
+$as_echo "using bdw-gc pkg-config module" >&6; }
+else
+  as_fn_error "no --with-target-bdw-gc options and no bdw-gc pkg-config module found" "$LINENO" 5
+fi
+  else
+        if test "x$with_target_bdw_gc_include" = x && test "x$with_target_bdw_gc_lib" != x; then
+      as_fn_error "found --with-target-bdw-gc-lib but --with-target-bdw-gc-include missing" "$LINENO" 5
+    elif test "x$with_target_bdw_gc_include" != x && test "x$with_target_bdw_gc_lib" = x; then
+      as_fn_error "found --with-target-bdw-gc-include but --with-target-bdw-gc-lib missing" "$LINENO" 5
+    else
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: using paths configured with --with-target-bdw-gc options" >&5
+$as_echo "using paths configured with --with-target-bdw-gc options" >&6; }
+    fi
+    mldir=`${CC-gcc} --print-multi-directory 2>/dev/null`
+    bdw_val=
+    if test "x$with_target_bdw_gc" != x; then
+      for i in `echo $with_target_bdw_gc | tr ',' ' '`; do
+        case "$i" in
+          *=*) sd=${i%%=*}; d=${i#*=} ;;
+          *) sd=.; d=$i ;;
+        esac
+        if test "$mldir" = "$sd"; then
+          bdw_val=$d
+        fi
+      done
+      if test "x$bdw_val" = x; then
+        as_fn_error "no multilib path ($mldir) found in --with-target-bdw-gc" "$LINENO" 5
+      fi
+      bdw_inc_dir="$bdw_val/include"
+      bdw_lib_dir="$bdw_val/lib"
+    fi
+    bdw_val=
+    if test "x$with_target_bdw_gc_include" != x; then
+      for i in `echo $with_target_bdw_gc_include | tr ',' ' '`; do
+        case "$i" in
+          *=*) sd=${i%%=*}; d=${i#*=} ;;
+          *) sd=.; d=$i ;;
+        esac
+        if test "$mldir" = "$sd"; then
+          bdw_val=$d
+        fi
+      done
+      if test "x$bdw_val" = x; then
+        as_fn_error "no multilib path ($mldir) found in --with-target-bdw-gc-include" "$LINENO" 5
+      fi
+      bdw_inc_dir="$bdw_val"
+    fi
+    bdw_val=
+    if test "x$with_target_bdw_gc_lib" != x; then
+      for i in `echo $with_target_bdw_gc_lib | tr ',' ' '`; do
+        case "$i" in
+          *=*) sd=${i%%=*}; d=${i#*=} ;;
+          *) sd=.; d=$i ;;
+        esac
+        if test "$mldir" = "$sd"; then
+          bdw_val=$d
+        fi
+      done
+      if test "x$bdw_val" = x; then
+        as_fn_error "no multilib path ($mldir) found in --with-target-bdw-gc-lib" "$LINENO" 5
+      fi
+      bdw_lib_dir="$bdw_val"
+    fi
+    if test "x$bdw_inc_dir" = x; then
+      as_fn_error "no multilib path ($mldir) found in --with-target-bdw-gc-include" "$LINENO" 5
+    fi
+    if test "x$bdw_lib_dir" = x; then
+      as_fn_error "no multilib path ($mldir) found in --with-target-bdw-gc-lib" "$LINENO" 5
+    fi
+    BDW_GC_CFLAGS="-I$bdw_inc_dir"
+    BDW_GC_LIBS="-L$bdw_lib_dir -lgc"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
+$as_echo "found" >&6; }
+  fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for system boehm-gc" >&5
+$as_echo_n "checking for system boehm-gc... " >&6; }
+  save_CFLAGS=$CFLAGS
+  save_LIBS=$LIBS
+  CFLAGS="$CFLAGS $BDW_GC_CFLAGS"
+  LIBS="$LIBS $BDW_GC_LIBS"
+      if test x$gcc_no_link = xyes; then
+  as_fn_error "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <gc/gc.h>
+int
+main ()
+{
+GC_init()
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+      if test "$cross_compiling" = yes; then :
+          system_bdw_gc_found=no
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+        #include <gc/gc.h>
+        int main() {
+          GC_init();
+          return 0;
+        }
+
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  system_bdw_gc_found=yes
+else
+  system_bdw_gc_found=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+
+else
+  system_bdw_gc_found=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  CFLAGS=$save_CFLAGS
+  LIBS=$save_LIBS
+  if test x$enable_objc_gc = xauto && test x$system_bdw_gc_found = xno; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: system bdw-gc not found, not building libobjc_gc" >&5
+$as_echo "$as_me: WARNING: system bdw-gc not found, not building libobjc_gc" >&2;}
+    use_bdw_gc=no
+  elif test x$enable_objc_gc = xyes && test x$system_bdw_gc_found = xno; then
+    as_fn_error "system bdw-gc required but not found" "$LINENO" 5
+  else
+    use_bdw_gc=yes
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
+$as_echo "found" >&6; }
+  fi
+esac
+
+if test "$use_bdw_gc" = no; then
+  OBJC_GCFLAGS=''
+  OBJC_BOEHM_GC=''
+  OBJC_BOEHM_GC_INCLUDES=''
+  OBJC_BOEHM_GC_LIBS=''
+else
+  OBJC_GCFLAGS='-DOBJC_WITH_GC=1'
+  OBJC_BOEHM_GC='libobjc_gc$(libsuffix).la'
+  OBJC_BOEHM_GC_INCLUDES=$BDW_GC_CFLAGS
+  OBJC_BOEHM_GC_LIBS=$BDW_GC_LIBS
+fi
+
+
+
+
+
 # ------
 # Output
 # ------
diff --git a/libobjc/configure.ac b/libobjc/configure.ac
index 9dbc16cb9a8..0497836a964 100644
--- a/libobjc/configure.ac
+++ b/libobjc/configure.ac
@@ -18,6 +18,8 @@
 #along with GCC; see the file COPYING3.  If not see
 #<http://www.gnu.org/licenses/>.
 
+m4_include([../config/pkg.m4])
+
 AC_PREREQ(2.64)
 AC_INIT(package-unused, version-unused,, libobjc)
 AC_CONFIG_SRCDIR([objc/objc.h])
@@ -57,26 +59,6 @@ AC_ARG_ENABLE(version-specific-runtime-libs,
 [version_specific_libs=no])
 AC_MSG_RESULT($version_specific_libs)
 
-AC_ARG_ENABLE(objc-gc,
-[  --enable-objc-gc       enable the use of Boehm's garbage collector with
-                          the GNU Objective-C runtime.],
-[case $enable_objc_gc in
-  no)
-    OBJC_GCFLAGS=''
-    OBJC_BOEHM_GC=''
-    OBJC_BOEHM_GC_INCLUDES=''
-    ;;
-  *)
-    OBJC_GCFLAGS='-DOBJC_WITH_GC=1'
-    OBJC_BOEHM_GC='libobjc_gc$(libsuffix).la'
-    OBJC_BOEHM_GC_INCLUDES='-I$(top_srcdir)/../boehm-gc/include -I../boehm-gc/include'
-    ;;
-esac],
-[OBJC_GCFLAGS=''; OBJC_BOEHM_GC=''; OBJC_BOEHM_GC_INCLUDES=''])
-AC_SUBST(OBJC_GCFLAGS)
-AC_SUBST(OBJC_BOEHM_GC)
-AC_SUBST(OBJC_BOEHM_GC_INCLUDES)
-
 # -----------
 # Directories
 # -----------
@@ -214,6 +196,160 @@ GCC_CHECK_TLS
 
 gt_BITFIELD_TYPE_MATTERS
 
+# -----------
+# boehm-gc
+# -----------
+
+AC_ARG_ENABLE(objc-gc,
+[AS_HELP_STRING([--enable-objc-gc],
+		[enable use of Boehm's garbage collector with the
+		 GNU Objective-C runtime])])
+AC_ARG_WITH([target-bdw-gc],
+[AS_HELP_STRING([--with-target-bdw-gc=PATHLIST],
+		[specify prefix directory for installed bdw-gc package.
+		 Equivalent to --with-target-bdw-gc-include=PATH/include
+		 plus --with-target-bdw-gc-lib=PATH/lib])])
+AC_ARG_WITH([target-bdw-gc-include],
+[AS_HELP_STRING([--with-target-bdw-gc-include=PATHLIST],
+		[specify directories for installed bdw-gc include files])])
+AC_ARG_WITH([target-bdw-gc-lib],
+[AS_HELP_STRING([--with-target-bdw-gc-lib=PATHLIST],
+		[specify directories for installed bdw-gc library])])
+		  
+case "$enable_objc_gc" in
+no)
+  use_bdw_gc=no
+  ;;
+*)
+  AC_MSG_CHECKING([for bdw garbage collector])
+  if test "x$with_target_bdw_gc$with_target_bdw_gc_include$with_target_bdw_gc_lib" = x; then
+    dnl no bdw-gw options, fall back to the bdw-gc pkg-config module
+    PKG_CHECK_EXISTS(bdw-gc,
+      AC_MSG_RESULT([using bdw-gc pkg-config module]),
+      AC_MSG_ERROR([no --with-target-bdw-gc options and no bdw-gc pkg-config module found]))
+  else
+    dnl bdw-gw options passed by configure flags
+    if test "x$with_target_bdw_gc_include" = x && test "x$with_target_bdw_gc_lib" != x; then
+      AC_MSG_ERROR([found --with-target-bdw-gc-lib but --with-target-bdw-gc-include missing])
+    elif test "x$with_target_bdw_gc_include" != x && test "x$with_target_bdw_gc_lib" = x; then
+      AC_MSG_ERROR([found --with-target-bdw-gc-include but --with-target-bdw-gc-lib missing])
+    else
+      AC_MSG_RESULT([using paths configured with --with-target-bdw-gc options])
+    fi
+    mldir=`${CC-gcc} --print-multi-directory 2>/dev/null`
+    bdw_val=
+    if test "x$with_target_bdw_gc" != x; then
+      for i in `echo $with_target_bdw_gc | tr ',' ' '`; do
+        case "$i" in
+          *=*) sd=${i%%=*}; d=${i#*=} ;;
+          *) sd=.; d=$i ;;
+        esac
+        if test "$mldir" = "$sd"; then
+          bdw_val=$d
+        fi
+      done
+      if test "x$bdw_val" = x; then
+        AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc])
+      fi
+      bdw_inc_dir="$bdw_val/include"
+      bdw_lib_dir="$bdw_val/lib"
+    fi
+    bdw_val=
+    if test "x$with_target_bdw_gc_include" != x; then
+      for i in `echo $with_target_bdw_gc_include | tr ',' ' '`; do
+        case "$i" in
+          *=*) sd=${i%%=*}; d=${i#*=} ;;
+          *) sd=.; d=$i ;;
+        esac
+        if test "$mldir" = "$sd"; then
+          bdw_val=$d
+        fi
+      done
+      if test "x$bdw_val" = x; then
+        AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-include])
+      fi
+      bdw_inc_dir="$bdw_val"
+    fi
+    bdw_val=
+    if test "x$with_target_bdw_gc_lib" != x; then
+      for i in `echo $with_target_bdw_gc_lib | tr ',' ' '`; do
+        case "$i" in
+          *=*) sd=${i%%=*}; d=${i#*=} ;;
+          *) sd=.; d=$i ;;
+        esac
+        if test "$mldir" = "$sd"; then
+          bdw_val=$d
+        fi
+      done
+      if test "x$bdw_val" = x; then
+        AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-lib])
+      fi
+      bdw_lib_dir="$bdw_val"
+    fi
+    if test "x$bdw_inc_dir" = x; then
+      AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-include])
+    fi
+    if test "x$bdw_lib_dir" = x; then
+      AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-lib])
+    fi
+    BDW_GC_CFLAGS="-I$bdw_inc_dir"
+    BDW_GC_LIBS="-L$bdw_lib_dir -lgc"
+    AC_MSG_RESULT([found])
+  fi
+
+  AC_MSG_CHECKING([for system boehm-gc])
+  save_CFLAGS=$CFLAGS
+  save_LIBS=$LIBS
+  CFLAGS="$CFLAGS $BDW_GC_CFLAGS"
+  LIBS="$LIBS $BDW_GC_LIBS"
+  dnl the link test is not good enough for ARM32 multilib detection,
+  dnl first check to link, then to run
+  AC_LINK_IFELSE(
+    [AC_LANG_PROGRAM([#include <gc/gc.h>],[GC_init()])],
+    [
+      AC_RUN_IFELSE([AC_LANG_SOURCE([[
+        #include <gc/gc.h>
+        int main() {
+          GC_init();
+          return 0;
+        }
+        ]])],
+        [system_bdw_gc_found=yes],
+        [system_bdw_gc_found=no],
+        dnl assume no system boehm-gc for cross builds ...
+        [system_bdw_gc_found=no]
+      )
+    ],
+    [system_bdw_gc_found=no])
+  CFLAGS=$save_CFLAGS
+  LIBS=$save_LIBS
+  if test x$enable_objc_gc = xauto && test x$system_bdw_gc_found = xno; then
+    AC_MSG_WARN([system bdw-gc not found, not building libobjc_gc])
+    use_bdw_gc=no
+  elif test x$enable_objc_gc = xyes && test x$system_bdw_gc_found = xno; then
+    AC_MSG_ERROR([system bdw-gc required but not found])
+  else
+    use_bdw_gc=yes
+    AC_MSG_RESULT([found])
+  fi
+esac
+
+if test "$use_bdw_gc" = no; then
+  OBJC_GCFLAGS=''
+  OBJC_BOEHM_GC=''
+  OBJC_BOEHM_GC_INCLUDES=''
+  OBJC_BOEHM_GC_LIBS=''
+else
+  OBJC_GCFLAGS='-DOBJC_WITH_GC=1'
+  OBJC_BOEHM_GC='libobjc_gc$(libsuffix).la'
+  OBJC_BOEHM_GC_INCLUDES=$BDW_GC_CFLAGS
+  OBJC_BOEHM_GC_LIBS=$BDW_GC_LIBS
+fi
+AC_SUBST(OBJC_GCFLAGS)
+AC_SUBST(OBJC_BOEHM_GC)
+AC_SUBST(OBJC_BOEHM_GC_INCLUDES)
+AC_SUBST(OBJC_BOEHM_GC_LIBS)
+
 # ------
 # Output
 # ------
diff --git a/libobjc/gc.c b/libobjc/gc.c
index a090a522ddf..d3ff1bc2517 100644
--- a/libobjc/gc.c
+++ b/libobjc/gc.c
@@ -36,7 +36,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include "objc/runtime.h"
 #include "objc-private/module-abi-8.h"
 
-#include <gc.h>
+#include <gc/gc.h>
 #include <limits.h>
 
 /* gc_typed.h uses the following but doesn't declare them */
@@ -44,7 +44,7 @@ typedef GC_word word;
 typedef GC_signed_word signed_word;
 #define BITS_PER_WORD (CHAR_BIT * sizeof (word))
 
-#include <gc_typed.h>
+#include <gc/gc_typed.h>
 
 /* The following functions set up in `mask` the corresponding pointers.
    The offset is incremented with the size of the type.  */
diff --git a/libobjc/memory.c b/libobjc/memory.c
index ee28f82cf58..a439e587ab2 100644
--- a/libobjc/memory.c
+++ b/libobjc/memory.c
@@ -41,7 +41,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include "objc/runtime.h"
 
 #if OBJC_WITH_GC
-#include <gc.h>
+#include <gc/gc.h>
 
 void *
 objc_malloc (size_t size)
diff --git a/libobjc/objects.c b/libobjc/objects.c
index 056f82d4963..09aa049000e 100644
--- a/libobjc/objects.c
+++ b/libobjc/objects.c
@@ -31,8 +31,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include <string.h>                     /* For memcpy()  */
 
 #if OBJC_WITH_GC
-# include <gc.h>
-# include <gc_typed.h>
+# include <gc/gc.h>
+# include <gc/gc_typed.h>
 #endif
 
 /* FIXME: The semantics of extraBytes are not really clear.  */