gc6.6 tarball importgc6_6

20 files changed, 325 insertions, 142 deletions

diff --git a/Makefile.am b/Makefile.am
index 7ce69351..89594f9d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -105,10 +105,18 @@ include/gc_pthread_redirects.h include/gc_config_macros.h \
 include/gc_mark.h @addincludes@
 
 ## FIXME: we shouldn't have to do this, but automake forces us to.
+if COMPILER_XLC
+  ## XLC neither requires nor tolerates the unnecessary assembler goop
+  ASM_CPP_OPTIONS =
+else
+  ## We use -Wp,-P to strip #line directives.  Irix `as' chokes on
+  ## these.
+  ASM_CPP_OPTIONS = -Wp,-P -x assembler-with-cpp
+endif
 .s.lo:
 ## We use -Wp,-P to strip #line directives.  Irix `as' chokes on
 ## these.
-	$(LTCOMPILE) -Wp,-P -x assembler-with-cpp -c $<
+	$(LTCOMPILE) $(ASM_CPP_OPTIONS) -c $<
 
 ## We have our own definition of LTCOMPILE because we want to use our
 ## CFLAGS, not those passed in from the top level make.
diff --git a/Makefile.in b/Makefile.in
index 5a73b024..c89c84cb 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -171,6 +171,8 @@ CCAS = @CCAS@
 CCASFLAGS = @CCASFLAGS@ $(DEFS)
 CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
+COMPILER_XLC_FALSE = @COMPILER_XLC_FALSE@
+COMPILER_XLC_TRUE = @COMPILER_XLC_TRUE@
 CPLUSPLUS_FALSE = @CPLUSPLUS_FALSE@
 CPLUSPLUS_TRUE = @CPLUSPLUS_TRUE@
 CPP = @CPP@
@@ -359,6 +361,8 @@ test_cpp_SOURCES = tests/test_cpp.cc
 test_cpp_LDADD = ./libgc.la ./libgccpp.la $(THREADDLLIBS) $(UNWINDLIBS) $(EXTRA_TEST_LIBS)
 TESTS = gctest $(extra_checks)
 all_objs = @addobjs@ $(libgc_la_OBJECTS)
+@COMPILER_XLC_FALSE@ASM_CPP_OPTIONS = -Wp,-P -x assembler-with-cpp
+@COMPILER_XLC_TRUE@ASM_CPP_OPTIONS = 
 LTCOMPILE = $(LIBTOOL) --mode=compile $(CC) $(DEFS) $(INCLUDES) \
 	$(AM_CPPFLAGS) $(CPPFLAGS) \
 	$(AM_CFLAGS) $(MY_CFLAGS) $(GC_CFLAGS) 
@@ -1051,9 +1055,8 @@ $(all_objs) : include/private/gcconfig.h include/private/gc_priv.h \
 include/private/gc_hdrs.h include/gc.h include/gc_gcj.h \
 include/gc_pthread_redirects.h include/gc_config_macros.h \
 include/gc_mark.h @addincludes@
-
 .s.lo:
-	$(LTCOMPILE) -Wp,-P -x assembler-with-cpp -c $<
+	$(LTCOMPILE) $(ASM_CPP_OPTIONS) -c $<
 
 #
 # :GOTCHA: GNU make rule for making .s out of .S is flawed, 
diff --git a/alpha_mach_dep.S b/alpha_mach_dep.S
index 53547307..d4def240 100644
--- a/alpha_mach_dep.S
+++ b/alpha_mach_dep.S
@@ -1,4 +1,3 @@
- # $Id: alpha_mach_dep.s,v 1.2 1993/01/18 22:54:51 dosser Exp $
 	.arch ev6
 
         .text
@@ -12,13 +11,13 @@ GC_push_regs:
         .mask   0x04000000, 0
         .frame  $sp, 16, $26, 0
 
- # $0		integer result
- # $1-$8	temp regs - not preserved cross calls
- # $9-$15	call saved regs
- # $16-$21	argument regs - not preserved cross calls
- # $22-$28	temp regs - not preserved cross calls
- # $29		global pointer - not preserved cross calls
- # $30		stack pointer
+/* $0		integer result                                                */
+/* $1-$8	temp regs - not preserved cross calls                         */
+/* $9-$15	call saved regs                                               */
+/* $16-$21	argument regs - not preserved cross calls                     */
+/* $22-$28	temp regs - not preserved cross calls                         */
+/* $29		global pointer - not preserved cross calls                    */
+/* $30		stack pointer                                                 */
 
 # define call_push(x)			\
 	mov   x, $16;			\
@@ -33,12 +32,12 @@ GC_push_regs:
         call_push($14)
         call_push($15)
 
- # $f0-$f1	floating point results
- # $f2-$f9	call saved regs
- # $f10-$f30	temp regs - not preserved cross calls
+/* $f0-$f1	floating point results                                        */
+/* $f2-$f9	call saved regs                                               */
+/* $f10-$f30	temp regs - not preserved cross calls                         */
 
-	# Use the most efficient transfer method for this hardware.
-	# Bit 1 detects the FIX extension, which includes ftoit.
+	/* Use the most efficient transfer method for this hardware. */
+	/* Bit 1 detects the FIX extension, which includes ftoit. */
 	amask	2, $0
 	bne	$0, $use_stack
 
diff --git a/configure b/configure
index 61f41465..059365da 100755
--- a/configure
+++ b/configure
@@ -1,7 +1,7 @@
 #! /bin/sh
 # From configure.in Revision: 1.2 .
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.59 for gc 6.5.
+# Generated by GNU Autoconf 2.59 for gc 6.6.
 #
 # Report bugs to <Hans.Boehm@hp.com>.
 #
@@ -429,8 +429,8 @@ SHELL=${CONFIG_SHELL-/bin/sh}
 # Identity of this package.
 PACKAGE_NAME='gc'
 PACKAGE_TARNAME='gc'
-PACKAGE_VERSION='6.5'
-PACKAGE_STRING='gc 6.5'
+PACKAGE_VERSION='6.6'
+PACKAGE_STRING='gc 6.6'
 PACKAGE_BUGREPORT='Hans.Boehm@hp.com'
 
 ac_unique_file="gcj_mlc.c"
@@ -471,7 +471,7 @@ ac_includes_default="\
 # include <unistd.h>
 #endif"
 
-ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS build build_cpu build_vendor build_os host host_cpu host_vendor host_os target target_cpu target_vendor target_os INSTALL_PROGRAM INSTALL_SCRIPT INSTALL_DATA CYGPATH_W PACKAGE VERSION ACLOCAL AUTOCONF AUTOMAKE AUTOHEADER MAKEINFO install_sh STRIP ac_ct_STRIP INSTALL_STRIP_PROGRAM mkdir_p AWK SET_MAKE am__leading_dot AMTAR am__tar am__untar GC_VERSION CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT DEPDIR am__include am__quote AMDEP_TRUE AMDEP_FALSE AMDEPBACKSLASH CCDEPMODE am__fastdepCC_TRUE am__fastdepCC_FALSE CXX CXXFLAGS ac_ct_CXX CXXDEPMODE am__fastdepCXX_TRUE am__fastdepCXX_FALSE CCAS CCASFLAGS AR ac_ct_AR RANLIB ac_ct_RANLIB MAINTAINER_MODE_TRUE MAINTAINER_MODE_FALSE MAINT GC_CFLAGS THREADDLLIBS POWERPC_DARWIN_TRUE POWERPC_DARWIN_FALSE EXTRA_TEST_LIBS target_all CPLUSPLUS_TRUE CPLUSPLUS_FALSE INCLUDES CXXINCLUDES addobjs addincludes addlibs addtests LN_S ECHO CPP EGREP LIBTOOL MY_CFLAGS UNWINDLIBS USE_LIBDIR_TRUE USE_LIBDIR_FALSE LIBOBJS LTLIBOBJS'
+ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS build build_cpu build_vendor build_os host host_cpu host_vendor host_os target target_cpu target_vendor target_os INSTALL_PROGRAM INSTALL_SCRIPT INSTALL_DATA CYGPATH_W PACKAGE VERSION ACLOCAL AUTOCONF AUTOMAKE AUTOHEADER MAKEINFO install_sh STRIP ac_ct_STRIP INSTALL_STRIP_PROGRAM mkdir_p AWK SET_MAKE am__leading_dot AMTAR am__tar am__untar GC_VERSION CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT DEPDIR am__include am__quote AMDEP_TRUE AMDEP_FALSE AMDEPBACKSLASH CCDEPMODE am__fastdepCC_TRUE am__fastdepCC_FALSE CXX CXXFLAGS ac_ct_CXX CXXDEPMODE am__fastdepCXX_TRUE am__fastdepCXX_FALSE CCAS CCASFLAGS AR ac_ct_AR RANLIB ac_ct_RANLIB MAINTAINER_MODE_TRUE MAINTAINER_MODE_FALSE MAINT GC_CFLAGS THREADDLLIBS POWERPC_DARWIN_TRUE POWERPC_DARWIN_FALSE COMPILER_XLC_TRUE COMPILER_XLC_FALSE EXTRA_TEST_LIBS target_all CPLUSPLUS_TRUE CPLUSPLUS_FALSE INCLUDES CXXINCLUDES addobjs addincludes addlibs addtests LN_S ECHO CPP EGREP LIBTOOL MY_CFLAGS UNWINDLIBS USE_LIBDIR_TRUE USE_LIBDIR_FALSE LIBOBJS LTLIBOBJS'
 ac_subst_files=''
 
 # Initialize some variables set by options.
@@ -956,7 +956,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures gc 6.5 to adapt to many kinds of systems.
+\`configure' configures gc 6.6 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1023,7 +1023,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of gc 6.5:";;
+     short | recursive ) echo "Configuration of gc 6.6:";;
    esac
   cat <<\_ACEOF
 
@@ -1167,7 +1167,7 @@ fi
 test -n "$ac_init_help" && exit 0
 if $ac_init_version; then
   cat <<\_ACEOF
-gc configure 6.5
+gc configure 6.6
 generated by GNU Autoconf 2.59
 
 Copyright (C) 2003 Free Software Foundation, Inc.
@@ -1181,7 +1181,7 @@ cat >&5 <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by gc $as_me 6.5, which was
+It was created by gc $as_me 6.6, which was
 generated by GNU Autoconf 2.59.  Invocation command line was
 
   $ $0 $@
@@ -1953,7 +1953,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='gc'
- VERSION='6.5'
+ VERSION='6.6'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -4184,13 +4184,83 @@ else
 fi
 
 
+echo "$as_me:$LINENO: checking for xlc" >&5
+echo $ECHO_N "checking for xlc... $ECHO_C" >&6
+
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+ #ifndef __xlC__
+ # error
+ #endif
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  compiler_xlc=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+compiler_xlc=no
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+echo "$as_me:$LINENO: result: $compiler_xlc" >&5
+echo "${ECHO_T}$compiler_xlc" >&6
+
+
+if test $compiler_xlc = yes; then
+  COMPILER_XLC_TRUE=
+  COMPILER_XLC_FALSE='#'
+else
+  COMPILER_XLC_TRUE='#'
+  COMPILER_XLC_FALSE=
+fi
+
+if test $compiler_xlc = yes -a "$powerpc_darwin" = true; then
+  # the darwin stack-frame-walking code is completely broken on xlc
+  cat >>confdefs.h <<\_ACEOF
+#define DARWIN_DONT_PARSE_STACK 1
+_ACEOF
+
+fi
+
 # We never want libdl on darwin. It is a fake libdl that just ends up making
 # dyld calls anyway
 case "$host" in
   *-*-darwin*) ;;
   *)
-
-echo "$as_me:$LINENO: checking for dlopen in -ldl" >&5
+    echo "$as_me:$LINENO: checking for dlopen in -ldl" >&5
 echo $ECHO_N "checking for dlopen in -ldl... $ECHO_C" >&6
 if test "${ac_cv_lib_dl_dlopen+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -5982,7 +6052,7 @@ test "x$enable_libtool_lock" != xno && enable_libtool_lock=yes
 case $host in
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 5985 "configure"' > conftest.$ac_ext
+  echo '#line 6055 "configure"' > conftest.$ac_ext
   if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -6555,7 +6625,7 @@ chmod -w .
 save_CFLAGS="$CFLAGS"
 CFLAGS="$CFLAGS -o out/conftest2.$ac_objext"
 compiler_c_o=no
-if { (eval echo configure:6558: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>out/conftest.err; } && test -s out/conftest2.$ac_objext; then
+if { (eval echo configure:6628: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>out/conftest.err; } && test -s out/conftest2.$ac_objext; then
   # The compiler can only warn and ignore the option if not recognized
   # So say no if there are warnings
   if test -s out/conftest.err; then
@@ -8482,7 +8552,7 @@ else
     lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 8485 "configure"
+#line 8555 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -8580,7 +8650,7 @@ else
     lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 8583 "configure"
+#line 8653 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -9910,6 +9980,13 @@ echo "$as_me: error: conditional \"POWERPC_DARWIN\" was never defined.
 Usually this means the macro was only invoked conditionally." >&2;}
    { (exit 1); exit 1; }; }
 fi
+if test -z "${COMPILER_XLC_TRUE}" && test -z "${COMPILER_XLC_FALSE}"; then
+  { { echo "$as_me:$LINENO: error: conditional \"COMPILER_XLC\" was never defined.
+Usually this means the macro was only invoked conditionally." >&5
+echo "$as_me: error: conditional \"COMPILER_XLC\" was never defined.
+Usually this means the macro was only invoked conditionally." >&2;}
+   { (exit 1); exit 1; }; }
+fi
 if test -z "${CPLUSPLUS_TRUE}" && test -z "${CPLUSPLUS_FALSE}"; then
   { { echo "$as_me:$LINENO: error: conditional \"CPLUSPLUS\" was never defined.
 Usually this means the macro was only invoked conditionally." >&5
@@ -10195,7 +10272,7 @@ _ASBOX
 } >&5
 cat >&5 <<_CSEOF
 
-This file was extended by gc $as_me 6.5, which was
+This file was extended by gc $as_me 6.6, which was
 generated by GNU Autoconf 2.59.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -10253,7 +10330,7 @@ _ACEOF
 
 cat >>$CONFIG_STATUS <<_ACEOF
 ac_cs_version="\\
-gc config.status 6.5
+gc config.status 6.6
 configured by $0, generated by GNU Autoconf 2.59,
   with options \\"`echo "$ac_configure_args" | sed 's/[\\""\`\$]/\\\\&/g'`\\"
 
@@ -10528,6 +10605,8 @@ s,@GC_CFLAGS@,$GC_CFLAGS,;t t
 s,@THREADDLLIBS@,$THREADDLLIBS,;t t
 s,@POWERPC_DARWIN_TRUE@,$POWERPC_DARWIN_TRUE,;t t
 s,@POWERPC_DARWIN_FALSE@,$POWERPC_DARWIN_FALSE,;t t
+s,@COMPILER_XLC_TRUE@,$COMPILER_XLC_TRUE,;t t
+s,@COMPILER_XLC_FALSE@,$COMPILER_XLC_FALSE,;t t
 s,@EXTRA_TEST_LIBS@,$EXTRA_TEST_LIBS,;t t
 s,@target_all@,$target_all,;t t
 s,@CPLUSPLUS_TRUE@,$CPLUSPLUS_TRUE,;t t
diff --git a/configure.in b/configure.in
index 1fd9ece1..d81e2eaf 100644
--- a/configure.in
+++ b/configure.in
@@ -17,7 +17,7 @@ dnl Process this file with autoconf to produce configure.
 # Initialization
 # ==============
 
-AC_INIT(gc,6.5,Hans.Boehm@hp.com) 
+AC_INIT(gc,6.6,Hans.Boehm@hp.com) 
     ## version must conform to [0-9]+[.][0-9]+(alpha[0-9]+)?
 AC_CONFIG_SRCDIR(gcj_mlc.c)
 AC_CANONICAL_TARGET 
@@ -184,6 +184,19 @@ case "$host" in
 esac
 AM_CONDITIONAL(POWERPC_DARWIN,test x$powerpc_darwin = xtrue)
 
+AC_MSG_CHECKING(for xlc)
+AC_TRY_COMPILE([],[
+ #ifndef __xlC__
+ # error
+ #endif
+], [compiler_xlc=yes], [compiler_xlc=no])
+AC_MSG_RESULT($compiler_xlc)
+AM_CONDITIONAL(COMPILER_XLC,test $compiler_xlc = yes)
+if test $compiler_xlc = yes -a "$powerpc_darwin" = true; then
+  # the darwin stack-frame-walking code is completely broken on xlc
+  AC_DEFINE(DARWIN_DONT_PARSE_STACK)
+fi
+
 # We never want libdl on darwin. It is a fake libdl that just ends up making
 # dyld calls anyway
 case "$host" in
diff --git a/doc/Makefile.in b/doc/Makefile.in
index c712a665..179cfade 100644
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -86,6 +86,8 @@ CCAS = @CCAS@
 CCASFLAGS = @CCASFLAGS@
 CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
+COMPILER_XLC_FALSE = @COMPILER_XLC_FALSE@
+COMPILER_XLC_TRUE = @COMPILER_XLC_TRUE@
 CPLUSPLUS_FALSE = @CPLUSPLUS_FALSE@
 CPLUSPLUS_TRUE = @CPLUSPLUS_TRUE@
 CPP = @CPP@
diff --git a/doc/README b/doc/README
index a65757e3..a19cb302 100644
--- a/doc/README
+++ b/doc/README
@@ -28,7 +28,7 @@ are GPL'ed, but with an exception that should cover all uses in the
 collector.  (If you are concerned about such things, I recommend you look
 at the notice in config.guess or ltmain.sh.)
 
-This is version 6.5 of a conservative garbage collector for C and C++.
+This is version 6.6 of a conservative garbage collector for C and C++.
 
 You might find a more recent version of this at
 
diff --git a/doc/README.changes b/doc/README.changes
index 0bb4df51..97b0b684 100644
--- a/doc/README.changes
+++ b/doc/README.changes
@@ -2221,6 +2221,30 @@ Since GC6.4:
  - Fix stack_size assertion in GC_pthread_create.
  - Fix assertion in GC_steal_mark_stack.
   
+Since 6.5
+ - Fix CPU count detection for Irix and FreeBSD. (Thanks to Dan Bonachea.)
+ - Integrate Dan Bonachea's patch for the IBM XLC compiler on Darwin.
+ - Integrated Andreas Tobler's FreeBSD/PowerPC patch.
+ - Don't access the GC thread structure from the restart handler.  It's
+   unsafe, since the handler may run too late.  (Thanks to Ben Maurer for
+   tracking this down.)
+ - Applied Christian Thalinger's patch to change comment syntax in
+   alpha_mach_dep.S.
+ - Added test for GC_no_dls in GC_dyld_image_add for DARWIN. (Thanks to
+   Juan Jose Garcia Ripoli).
+ - Use LINUX_STACKBOTTOM for Linux/SH and LINUX/ARM. (Thanks to Sugioka
+   Toshinobu and Christian Thalinger.)
+ - Rewrote GC_parse_map_entry.  This assumed a fixed column layout of
+   /proc/self/maps on Linux.  This ceased to be true about 2 years ago.
+   The old code is probably quite problemetic with -DREDIRECT_MALLOC.  It
+   is also used by default for IA64, though I haven't seen actual failures
+   there.
+ - More consistently define HBLKSIZE to 4096 on 64 bit architectures with
+   4K pages.  (Thanks to Andrew Haley.)
+ - With win32 threads, GC_stop_world needs to acquire GC_write_cs.  (Thanks
+   to Ben Hutchings for the observation and patch.)
+ - Move up struct callinfo declaration to make gcc 4.0.2. happy.
+
 To do:
  - The USE_MUNMAP code should really use a separate data structure
    indexed by physical page to keep track of time since last use of
diff --git a/doc/README.linux b/doc/README.linux
index 1d0fd4c3..ec4e7e64 100644
--- a/doc/README.linux
+++ b/doc/README.linux
@@ -19,10 +19,10 @@ Linux threads.  These should not be touched by the client program.
 
 To use threads, you need to abide by the following requirements:
 
-1) You need to use LinuxThreads (which are included in libc6).
+1) You need to use LinuxThreads or NPTL (which are included in libc6).
 
    The collector relies on some implementation details of the LinuxThreads
-   package.  It is unlikely that this code will work on other
+   package.  This code may not work on other
    pthread implementations (in particular it will *not* work with
    MIT pthreads).
 
diff --git a/dyn_load.c b/dyn_load.c
index f8b4aa76..749bf824 100644
--- a/dyn_load.c
+++ b/dyn_load.c
@@ -1141,21 +1141,22 @@ static const char *GC_dyld_name_for_hdr(struct mach_header *hdr) {
 static void GC_dyld_image_add(struct mach_header* hdr, unsigned long slide) {
     unsigned long start,end,i;
     const struct section *sec;
+    if (GC_no_dls) return;
     for(i=0;i<sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]);i++) {
         sec = getsectbynamefromheader(
             hdr,GC_dyld_sections[i].seg,GC_dyld_sections[i].sect);
-            if(sec == NULL || sec->size == 0) continue;
-            start = slide + sec->addr;
-            end = start + sec->size;
-#		ifdef DARWIN_DEBUG
-                GC_printf4("Adding section at %p-%p (%lu bytes) from image %s\n",
+        if(sec == NULL || sec->size == 0) continue;
+        start = slide + sec->addr;
+        end = start + sec->size;
+#	ifdef DARWIN_DEBUG
+            GC_printf4("Adding section at %p-%p (%lu bytes) from image %s\n",
                 start,end,sec->size,GC_dyld_name_for_hdr(hdr));
-#			endif
+#       endif
         GC_add_roots((char*)start,(char*)end);
-        }
-#	ifdef DARWIN_DEBUG
-    GC_print_static_roots();
-#	endif
+    }
+#   ifdef DARWIN_DEBUG
+        GC_print_static_roots();
+#   endif
 }
 
 /* This should never be called by a thread holding the lock */
@@ -1168,15 +1169,15 @@ static void GC_dyld_image_remove(struct mach_header* hdr, unsigned long slide) {
         if(sec == NULL || sec->size == 0) continue;
         start = slide + sec->addr;
         end = start + sec->size;
-#		ifdef DARWIN_DEBUG
+#	ifdef DARWIN_DEBUG
             GC_printf4("Removing section at %p-%p (%lu bytes) from image %s\n",
                 start,end,sec->size,GC_dyld_name_for_hdr(hdr));
 #		endif
         GC_remove_roots((char*)start,(char*)end);
     }
-#	ifdef DARWIN_DEBUG
-    GC_print_static_roots();
-#	endif
+#   ifdef DARWIN_DEBUG
+        GC_print_static_roots();
+#   endif
 }
 
 void GC_register_dynamic_libraries() {
diff --git a/include/Makefile.in b/include/Makefile.in
index 1f6c7d27..271ad358 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -88,6 +88,8 @@ CCAS = @CCAS@
 CCASFLAGS = @CCASFLAGS@
 CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
+COMPILER_XLC_FALSE = @COMPILER_XLC_FALSE@
+COMPILER_XLC_TRUE = @COMPILER_XLC_TRUE@
 CPLUSPLUS_FALSE = @CPLUSPLUS_FALSE@
 CPLUSPLUS_TRUE = @CPLUSPLUS_TRUE@
 CPP = @CPP@
diff --git a/include/private/gc_priv.h b/include/private/gc_priv.h
index e5bd52b6..3d634cee 100644
--- a/include/private/gc_priv.h
+++ b/include/private/gc_priv.h
@@ -258,17 +258,6 @@ typedef char * ptr_t;	/* A generic pointer to which we can add	*/
 /*                               */
 /*********************************/
 
-#ifdef SAVE_CALL_CHAIN
-
-/* Fill in the pc and argument information for up to NFRAMES of my	*/
-/* callers.  Ignore my frame and my callers frame.			*/
-struct callinfo;
-void GC_save_callers GC_PROTO((struct callinfo info[NFRAMES]));
-  
-void GC_print_callers GC_PROTO((struct callinfo info[NFRAMES]));
-
-#endif
-
 #ifdef NEED_CALLINFO
     struct callinfo {
 	word ci_pc;  	/* Caller, not callee, pc	*/
@@ -282,6 +271,16 @@ void GC_print_callers GC_PROTO((struct callinfo info[NFRAMES]));
     };
 #endif
 
+#ifdef SAVE_CALL_CHAIN
+
+/* Fill in the pc and argument information for up to NFRAMES of my	*/
+/* callers.  Ignore my frame and my callers frame.			*/
+void GC_save_callers GC_PROTO((struct callinfo info[NFRAMES]));
+  
+void GC_print_callers GC_PROTO((struct callinfo info[NFRAMES]));
+
+#endif
+
 
 /*********************************/
 /*                               */
diff --git a/include/private/gcconfig.h b/include/private/gcconfig.h
index 9546c206..c028e5db 100644
--- a/include/private/gcconfig.h
+++ b/include/private/gcconfig.h
@@ -249,6 +249,10 @@
 #    define POWERPC
 #    define mach_type_known
 # endif
+# if defined(FREEBSD) && (defined(powerpc) || defined(__powerpc__))
+#    define POWERPC
+#    define mach_type_known
+# endif
 # if defined(LINUX) && defined(__mc68000__)
 #    define M68K
 #    define mach_type_known
@@ -767,6 +771,9 @@
 #     if defined(__powerpc64__)
 #       define ALIGNMENT 8
 #       define CPP_WORDSZ 64
+#       ifndef HBLKSIZE
+#         define HBLKSIZE 4096
+#       endif
 #     else
 #       define ALIGNMENT 4
 #     endif
@@ -814,6 +821,22 @@
          should be looked into some more */
 #     define NO_PTHREAD_TRYLOCK
 #   endif
+#   ifdef FREEBSD
+#       define ALIGNMENT 4
+#       define OS_TYPE "FREEBSD"
+#       ifndef GC_FREEBSD_THREADS
+#           define MPROTECT_VDB
+#       endif
+#       define SIG_SUSPEND SIGUSR1
+#       define SIG_THR_RESTART SIGUSR2
+#       define FREEBSD_STACKBOTTOM
+#       ifdef __ELF__
+#           define DYNAMIC_LOADING
+#       endif
+        extern char etext[];
+        extern char * GC_FreeBSDGetDataStart();
+#       define DATASTART GC_FreeBSDGetDataStart(0x1000, &etext)
+#   endif
 #   ifdef NETBSD
 #     define ALIGNMENT 4
 #     define OS_TYPE "NETBSD"
@@ -1739,12 +1762,14 @@
 #   define MACH_TYPE "S390"
 #   define USE_GENERIC_PUSH_REGS
 #   ifndef __s390x__
-#   define ALIGNMENT 4
-#   define CPP_WORDSZ 32
+#     define ALIGNMENT 4
+#     define CPP_WORDSZ 32
 #   else
-#   define ALIGNMENT 8
-#   define CPP_WORDSZ 64
-#   define HBLKSIZE 4096
+#     define ALIGNMENT 8
+#     define CPP_WORDSZ 64
+#   endif
+#   ifndef HBLKSIZE
+#     define HBLKSIZE 4096
 #   endif
 #   ifdef LINUX
 #       define OS_TYPE "LINUX"
@@ -1784,7 +1809,7 @@
 #   endif
 #   ifdef LINUX
 #       define OS_TYPE "LINUX"
-#       define HEURISTIC1
+#       define LINUX_STACKBOTTOM
 #       undef STACK_GRAN
 #       define STACK_GRAN 0x10000000
 #       define USE_GENERIC_PUSH_REGS
@@ -1849,7 +1874,7 @@
 #   endif
 #   ifdef LINUX
 #     define OS_TYPE "LINUX"
-#     define STACKBOTTOM ((ptr_t) 0x7c000000)
+#     define LINUX_STACKBOTTOM
 #     define USE_GENERIC_PUSH_REGS
 #     define DYNAMIC_LOADING
 #     define SEARCH_FOR_DATA_START
diff --git a/include/private/pthread_stop_world.h b/include/private/pthread_stop_world.h
index 054c7a0e..6f9197a1 100644
--- a/include/private/pthread_stop_world.h
+++ b/include/private/pthread_stop_world.h
@@ -2,7 +2,6 @@
 #define GC_PTHREAD_STOP_WORLD_H
 
 struct thread_stop_info {
-    int	signal;
     word last_stop_count;	/* GC_last_stop_count value when thread	*/
     				/* last successfully handled a suspend	*/
     				/* signal.				*/
diff --git a/mach_dep.c b/mach_dep.c
index dca02a4d..ba1e0b6f 100644
--- a/mach_dep.c
+++ b/mach_dep.c
@@ -27,6 +27,10 @@
 #   endif
 # endif
 
+#if defined(RS6000) || defined(POWERPC)
+# include <ucontext.h>
+#endif
+
 #if defined(__MWERKS__) && !defined(POWERPC)
 
 asm static void PushMacRegisters()
diff --git a/os_dep.c b/os_dep.c
index 358ab380..fb50a455 100644
--- a/os_dep.c
+++ b/os_dep.c
@@ -60,6 +60,10 @@
 #   include <signal.h>
 # endif
 
+#if defined(LINUX) || defined(LINUX_STACKBOTTOM)
+# include <ctype.h>
+#endif
+
 /* Blatantly OS dependent routines, except for those that are related 	*/
 /* to dynamic loading.							*/
 
@@ -80,7 +84,7 @@
 #   define NEED_FIND_LIMIT
 # endif
 
-#if defined(FREEBSD) && defined(I386)
+#if defined(FREEBSD) && (defined(I386) || defined(powerpc) || defined(__powerpc__))
 #  include <machine/trap.h>
 #  if !defined(PCR)
 #    define NEED_FIND_LIMIT
@@ -245,30 +249,11 @@ word GC_apply_to_maps(word (*fn)(char *))
 //  XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537     name of mapping...\n
 //  ^^^^^^^^ ^^^^^^^^ ^^^^          ^^
 //  start    end      prot          maj_dev
-//  0        9        18            32
-//  
-//  For 64 bit ABIs:
-//  0	     17	      34	    56
 //
-//  The parser is called with a pointer to the entry and the return value
-//  is either NULL or is advanced to the next entry(the byte after the
-//  trailing '\n'.)
+//  Note that since about auguat 2003 kernels, the columns no longer have
+//  fixed offsets on 64-bit kernels.  Hence we no longer rely on fixed offsets
+//  anywhere, which is safer anyway.
 //
-#if CPP_WORDSZ == 32
-# define OFFSET_MAP_START   0
-# define OFFSET_MAP_END     9
-# define OFFSET_MAP_PROT   18
-# define OFFSET_MAP_MAJDEV 32
-# define ADDR_WIDTH 	    8
-#endif
-
-#if CPP_WORDSZ == 64
-# define OFFSET_MAP_START   0
-# define OFFSET_MAP_END    17
-# define OFFSET_MAP_PROT   34
-# define OFFSET_MAP_MAJDEV 56
-# define ADDR_WIDTH 	   16
-#endif
 
 /*
  * Assign various fields of the first line in buf_ptr to *start, *end,
@@ -277,36 +262,46 @@ word GC_apply_to_maps(word (*fn)(char *))
 char *GC_parse_map_entry(char *buf_ptr, word *start, word *end,
                                 char *prot_buf, unsigned int *maj_dev)
 {
-    char *tok;
+    char *start_start, *end_start, *prot_start, *maj_dev_start;
+    char *p;
+    char *endp;
 
     if (buf_ptr == NULL || *buf_ptr == '\0') {
         return NULL;
     }
 
-    memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4);
-    				/* do the protections first. */
+    p = buf_ptr;
+    while (isspace(*p)) ++p;
+    start_start = p;
+    GC_ASSERT(isxdigit(*start_start));
+    *start = strtoul(start_start, &endp, 16); p = endp;
+    GC_ASSERT(*p=='-');
+
+    ++p;
+    end_start = p;
+    GC_ASSERT(isxdigit(*end_start));
+    *end = strtoul(end_start, &endp, 16); p = endp;
+    GC_ASSERT(isspace(*p));
+
+    while (isspace(*p)) ++p;
+    prot_start = p;
+    GC_ASSERT(*prot_start == 'r' || *prot_start == '-');
+    memcpy(prot_buf, prot_start, 4);
     prot_buf[4] = '\0';
-
-    if (prot_buf[1] == 'w') {/* we can skip all of this if it's not writable. */
-
-        tok = buf_ptr;
-        buf_ptr[OFFSET_MAP_START+ADDR_WIDTH] = '\0';
-        *start = strtoul(tok, NULL, 16);
-
-        tok = buf_ptr+OFFSET_MAP_END;
-        buf_ptr[OFFSET_MAP_END+ADDR_WIDTH] = '\0';
-        *end = strtoul(tok, NULL, 16);
-
-        buf_ptr += OFFSET_MAP_MAJDEV;
-        tok = buf_ptr;
-        while (*buf_ptr != ':') buf_ptr++;
-        *buf_ptr++ = '\0';
-        *maj_dev = strtoul(tok, NULL, 16);
+    if (prot_buf[1] == 'w') {/* we can skip the rest if it's not writable. */
+	/* Skip past protection field to offset field */
+          while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
+          GC_ASSERT(isxdigit(*p));
+	/* Skip past offset field, which we ignore */
+          while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
+	maj_dev_start = p;
+        GC_ASSERT(isxdigit(*maj_dev_start));
+        *maj_dev = strtoul(maj_dev_start, NULL, 16);
     }
 
-    while (*buf_ptr && *buf_ptr++ != '\n');
+    while (*p && *p++ != '\n');
 
-    return buf_ptr;
+    return p;
 }
 
 #endif /* Need to parse /proc/self/maps. */	
@@ -855,7 +850,6 @@ ptr_t GC_get_stack_base()
 
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <ctype.h>
 
 # define STAT_SKIP 27   /* Number of fields preceding startstack	*/
 			/* field in /proc/self/stat			*/
@@ -1395,7 +1389,7 @@ int * etext_addr;
 }
 # endif
 
-# if defined(FREEBSD) && defined(I386) && !defined(PCR)
+# if defined(FREEBSD) && (defined(I386) || defined(powerpc) || defined(__powerpc__)) && !defined(PCR)
 /* Its unclear whether this should be identical to the above, or 	*/
 /* whether it should apply to non-X86 architectures.			*/
 /* For now we don't assume that there is always an empty page after	*/
diff --git a/pthread_stop_world.c b/pthread_stop_world.c
index d301f643..b9034dc7 100644
--- a/pthread_stop_world.c
+++ b/pthread_stop_world.c
@@ -7,6 +7,11 @@
 #include <semaphore.h>
 #include <errno.h>
 #include <unistd.h>
+#include <sys/time.h>
+#ifndef HPUX
+# include <sys/select.h>
+  /* Doesn't exist on HP/UX 11.11. */
+#endif
 
 #if DEBUG_THREADS
 
@@ -66,7 +71,22 @@ void GC_remove_allowed_signals(sigset_t *set)
 
 static sigset_t suspend_handler_mask;
 
-word GC_stop_count;	/* Incremented at the beginning of GC_stop_world. */
+volatile sig_atomic_t GC_stop_count;
+			/* Incremented at the beginning of GC_stop_world. */
+
+volatile sig_atomic_t GC_world_is_stopped = FALSE;
+			/* FALSE ==> it is safe for threads to restart, i.e. */
+			/* they will see another suspend signal before they  */
+			/* are expected to stop (unless they have voluntarily */
+			/* stopped).					     */
+
+void GC_brief_async_signal_safe_sleep()
+{
+    struct timeval tv;
+    tv.tv_sec = 0;
+    tv.tv_usec = 1000 * TIME_LIMIT / 2;
+    select(0, 0, 0, 0, &tv);
+}
 
 #ifdef GC_OSF1_THREADS
   GC_bool GC_retry_signals = TRUE;
@@ -175,16 +195,26 @@ void GC_suspend_handler_inner(ptr_t sig_arg)
     /* this thread a SIG_THR_RESTART signal.			*/
     /* SIG_THR_RESTART should be masked at this point.  Thus there	*/
     /* is no race.						*/
-    do {
-	    me->stop_info.signal = 0;
-	    sigsuspend(&suspend_handler_mask);        /* Wait for signal */
-    } while (me->stop_info.signal != SIG_THR_RESTART);
+    /* We do not continue until we receive a SIG_THR_RESTART,	*/
+    /* but we do not take that as authoritative.  (We may be	*/
+    /* accidentally restarted by one of the user signals we 	*/
+    /* don't block.)  After we receive the signal, we use a 	*/
+    /* primitive and expensive mechanism to wait until it's	*/
+    /* really safe to proceed.  Under normal circumstances,	*/
+    /* this code should not be executed.			*/
+    sigsuspend(&suspend_handler_mask);        /* Wait for signal */
+    while (GC_world_is_stopped && GC_stop_count == my_stop_count) {
+        GC_brief_async_signal_safe_sleep();
+#       if DEBUG_THREADS
+	  GC_err_printf0("Sleeping in signal handler");
+#       endif
+    }
     /* If the RESTART signal gets lost, we can still lose.  That should be  */
     /* less likely than losing the SUSPEND signal, since we don't do much   */
     /* between the sem_post and sigsuspend.	   			    */
-    /* We'd need more handshaking to work around that, since we don't want  */
-    /* to accidentally leave a RESTART signal pending, thus causing us to   */
-    /* continue prematurely in a future round.				    */ 
+    /* We'd need more handshaking to work around that.			    */
+    /* Simply dropping the sigsuspend call should be safe, but is unlikely  */
+    /* to be efficient.							    */
 
 #if DEBUG_THREADS
     GC_printf1("Continuing 0x%lx\n", my_thread);
@@ -194,20 +224,11 @@ void GC_suspend_handler_inner(ptr_t sig_arg)
 void GC_restart_handler(int sig)
 {
     pthread_t my_thread = pthread_self();
-    GC_thread me;
 
     if (sig != SIG_THR_RESTART) ABORT("Bad signal in suspend_handler");
 
-    /* Let the GC_suspend_handler() know that we got a SIG_THR_RESTART. */
-    /* The lookup here is safe, since I'm doing this on behalf  */
-    /* of a thread which holds the allocation lock in order	*/
-    /* to stop the world.  Thus concurrent modification of the	*/
-    /* data structure is impossible.				*/
-    me = GC_lookup_thread(my_thread);
-    me->stop_info.signal = SIG_THR_RESTART;
-
     /*
-    ** Note: even if we didn't do anything useful here,
+    ** Note: even if we don't do anything useful here,
     ** it would still be necessary to have a signal handler,
     ** rather than ignoring the signals, otherwise
     ** the signals will not be delivered at all, and
@@ -360,6 +381,7 @@ void GC_stop_world()
       /* We should have previously waited for it to become zero. */
 #   endif /* PARALLEL_MARK */
     ++GC_stop_count;
+    GC_world_is_stopped = TRUE;
     n_live_threads = GC_suspend_all();
 
       if (GC_retry_signals) {
@@ -422,6 +444,7 @@ void GC_start_world()
       GC_printf0("World starting\n");
 #   endif
 
+    GC_world_is_stopped = FALSE;
     for (i = 0; i < THREAD_TABLE_SZ; i++) {
       for (p = GC_threads[i]; p != 0; p = p -> next) {
         if (p -> id != my_thread) {
@@ -431,8 +454,7 @@ void GC_start_world()
 	    #if DEBUG_THREADS
 	      GC_printf1("Sending restart signal to 0x%lx\n", p -> id);
 	    #endif
-        
-        result = pthread_kill(p -> id, SIG_THR_RESTART);
+            result = pthread_kill(p -> id, SIG_THR_RESTART);
 	    switch(result) {
                 case ESRCH:
                     /* Not really there anymore.  Possible? */
diff --git a/pthread_support.c b/pthread_support.c
index 5eba6f7a..5b3808e7 100644
--- a/pthread_support.c
+++ b/pthread_support.c
@@ -116,7 +116,7 @@
 # include <semaphore.h>
 #endif /* !GC_DARWIN_THREADS */
 
-#if defined(GC_DARWIN_THREADS)
+#if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS)
 # include <sys/sysctl.h>
 #endif /* GC_DARWIN_THREADS */
 
@@ -877,11 +877,11 @@ void GC_thr_init()
 	  GC_nprocs = sysconf(_SC_NPROCESSORS_ONLN);
 	  if (GC_nprocs <= 0) GC_nprocs = 1;
 #	endif
-#       if defined(GC_FREEBSD_THREADS) || defined(GC_IRIX_THREADS)
-	  /* FIXME: For Irix, that's a ridiculous assumption.	*/
-          GC_nprocs = 1;
+#       if defined(GC_IRIX_THREADS)
+	  GC_nprocs = sysconf(_SC_NPROC_ONLN);
+	  if (GC_nprocs <= 0) GC_nprocs = 1;
 #       endif
-#       if defined(GC_DARWIN_THREADS)
+#       if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS)
 	  int ncpus = 1;
 	  size_t len = sizeof(ncpus);
 	  sysctl((int[2]) {CTL_HW, HW_NCPU}, 2, &ncpus, &len, NULL, 0);
diff --git a/version.h b/version.h
index 3d1c6063..e1fe24bd 100644
--- a/version.h
+++ b/version.h
@@ -2,7 +2,7 @@
 /* Eventually this one may become unnecessary.  For now we need	*/
 /* it to keep the old-style build process working.		*/
 #define GC_TMP_VERSION_MAJOR 6
-#define GC_TMP_VERSION_MINOR 5
+#define GC_TMP_VERSION_MINOR 6
 #define GC_TMP_ALPHA_VERSION GC_NOT_ALPHA
 
 #ifndef GC_NOT_ALPHA
diff --git a/win32_threads.c b/win32_threads.c
index 9fa75a4c..ba53d86f 100755
--- a/win32_threads.c
+++ b/win32_threads.c
@@ -233,6 +233,9 @@ void GC_push_thread_structures GC_PROTO((void))
 # endif
 }
 
+/* Defined in misc.c */
+extern CRITICAL_SECTION GC_write_cs;
+
 void GC_stop_world()
 {
   DWORD thread_id = GetCurrentThreadId();
@@ -241,6 +244,9 @@ void GC_stop_world()
   if (!GC_thr_initialized) ABORT("GC_stop_world() called before GC_thr_init()");
 
   GC_please_stop = TRUE;
+# ifndef CYGWIN32
+    EnterCriticalSection(&GC_write_cs);
+# endif /* !CYGWIN32 */
   for (i = 0; i <= GC_get_max_thread_index(); i++)
     if (thread_table[i].stack_base != 0
 	&& thread_table[i].id != thread_id) {
@@ -271,6 +277,9 @@ void GC_stop_world()
 #     endif
       thread_table[i].suspended = TRUE;
     }
+# ifndef CYGWIN32
+    LeaveCriticalSection(&GC_write_cs);
+# endif /* !CYGWIN32 */
 }
 
 void GC_start_world()