[Guile-commits] GNU Guile branch, stable-2.0, updated. v2.0.7-269-g337edc5

[Mark H Weaver]

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU Guile".

http://git.savannah.gnu.org/cgit/guile.git/commit/?id=337edc591ffd8f8ec4176b0112ad10da29818141

The branch, stable-2.0 has been updated
       via  337edc591ffd8f8ec4176b0112ad10da29818141 (commit)
       via  e459855936262b4bddaebd87a75abdc065799be2 (commit)
       via  663780bb1c881947b6e4f00c456b2b367701982d (commit)
      from  369294866dd7ee01ebf821df2a119ea55b1e68fd (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit 337edc591ffd8f8ec4176b0112ad10da29818141
Author: Mark H Weaver <address@hidden>
Date:   Sun Mar 31 15:23:32 2013 -0400

    Refactor port encoding modes: utf-8 and iconv
    
    Based on 6c98257f2ead0855f218369ea7f9a823cdb9727e by Andy Wingo.
    
    * libguile/ports-internal.h (struct scm_port_internal): Add a flag
      for the port encoding mode: UTF8 or iconv.  The iconv descriptors
      are now in a separate structure so that we can avoid attaching
      finalizers to the ports themselves in the future.
      (enum scm_port_encoding_mode): New enum.
      (struct scm_iconv_descriptors): New struct.
      (scm_i_port_iconv_descriptors): Add prototype.
    
    * libguile/ports.c (finalize_port): Don't close iconv descriptors here.
      (scm_new_port_table_entry): Adapt to the iconv descriptors being
      moved.  Initialize 'encoding_mode'.
      (scm_i_remove_port): Adapt to call 'close_iconv_descriptors'.
      (close_iconv_descriptors): New static function.
      (get_iconv_codepoint): Use 'scm_i_port_iconv_descriptors'.
      (get_codepoint): Check the port 'encoding_mode'.
      (finalize_iconv_descriptors, open_iconv_descriptors,
      close_iconv_descriptors, scm_i_port_iconv_descriptors): New static
      functions.
      (scm_i_set_port_encoding_x): Adapt to iconv descriptors being moved
      to separate structure, to set the 'encoding_mode' flag, and to use
      'open_iconv_descriptors' and 'close_iconv_descriptors'.
    
    * libguile/print.c (display_string_using_iconv): Use
      'scm_i_port_iconv_descriptors'.
      (display_string): Use 'encoding_mode' flag.

commit e459855936262b4bddaebd87a75abdc065799be2
Author: Mark H Weaver <address@hidden>
Date:   Sat Mar 30 22:34:56 2013 -0400

    Add internal-only port structure and move iconv descriptors there.
    
    * libguile/ports-internal.h: New file.
    
    * libguile/Makefile.am (noinst_HEADERS): Add ports-internal.h.
    
    * libguile/ports.h (scm_t_port): Add a comment mentioning that the
      'input_cd' and 'output_cd' fields of the public structure are no
      longer what they seem to be.
    
    * libguile/ports.c: Include ports-internal.h.
    
      (finalize_port, scm_i_remove_port, get_iconv_codepoint, get_codepoint,
      scm_i_set_port_encoding_x): Access 'input_cd' and 'output_cd' via the
      new internal port structure.
    
      (scm_new_port_table_entry): Allocate and initialize the internal port
      structure.
    
    * libguile/print.c: Include ports-internal.h.
    
      (display_string_using_iconv, display_string): Access 'input_cd' and
      'output_cd' via 'internal' pointer.

commit 663780bb1c881947b6e4f00c456b2b367701982d
Author: Mark H Weaver <address@hidden>
Date:   Sat Mar 30 23:09:01 2013 -0400

    Add 'scm_gc_typed_calloc' macro.
    
    * libguile/gc.h (scm_gc_typed_calloc): New macro.

-----------------------------------------------------------------------

Summary of changes:
 libguile/Makefile.am      |    5 +-
 libguile/gc.h             |    4 +-
 libguile/ports-internal.h |   60 +++++++++++
 libguile/ports.c          |  242 ++++++++++++++++++++++++++++-----------------
 libguile/ports.h          |   23 ++++-
 libguile/print.c          |   22 ++---
 6 files changed, 246 insertions(+), 110 deletions(-)
 create mode 100644 libguile/ports-internal.h

diff --git a/libguile/Makefile.am b/libguile/Makefile.am
index 4b1f96b..dcbdba1 100644
--- a/libguile/Makefile.am
+++ b/libguile/Makefile.am
@@ -1,6 +1,7 @@
 ## Process this file with Automake to create Makefile.in
 ##
-##     Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007, 
2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+##   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007,
+##     2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
 ##
 ##   This file is part of GUILE.
 ##
@@ -455,7 +456,7 @@ noinst_HEADERS = conv-integer.i.c conv-uinteger.i.c         
\
                  srfi-14.i.c                                   \
                  quicksort.i.c                                  \
                  win32-uname.h                                 \
-                private-gc.h private-options.h
+                private-gc.h private-options.h ports-internal.h
 
 # vm instructions
 noinst_HEADERS += vm-engine.c vm-i-system.c vm-i-scheme.c vm-i-loader.c
diff --git a/libguile/gc.h b/libguile/gc.h
index 9f00e01..a9a499b 100644
--- a/libguile/gc.h
+++ b/libguile/gc.h
@@ -3,7 +3,8 @@
 #ifndef SCM_GC_H
 #define SCM_GC_H
 
-/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2002, 2003, 2004, 2006, 2007, 
2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006,
+ *   2007, 2008, 2009, 2010, 2011, 2013 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -207,6 +208,7 @@ SCM_API char *scm_gc_strdup (const char *str, const char 
*what)
 SCM_API char *scm_gc_strndup (const char *str, size_t n, const char *what)
   SCM_MALLOC;
 
+#define scm_gc_typed_calloc(t) ((t *) scm_gc_calloc (sizeof (t), #t))
 
 #ifdef BUILDING_LIBGUILE
 #include "libguile/bdw-gc.h"
diff --git a/libguile/ports-internal.h b/libguile/ports-internal.h
new file mode 100644
index 0000000..bd25f3e
--- /dev/null
+++ b/libguile/ports-internal.h
@@ -0,0 +1,60 @@
+/*
+ * ports-internal.h - internal-only declarations for ports.
+ *
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef SCM_PORTS_INTERNAL
+#define SCM_PORTS_INTERNAL
+
+#include "libguile/_scm.h"
+#include "libguile/ports.h"
+
+enum scm_port_encoding_mode {
+  SCM_PORT_ENCODING_MODE_UTF8,
+  SCM_PORT_ENCODING_MODE_ICONV
+};
+
+typedef enum scm_port_encoding_mode scm_t_port_encoding_mode;
+
+/* This is a separate object so that only those ports that use iconv
+   cause finalizers to be registered (FIXME: although currently in 2.0
+   finalizers are always registered for ports anyway).  */
+struct scm_iconv_descriptors
+{
+  /* input/output iconv conversion descriptors */
+  void *input_cd;
+  void *output_cd;
+};
+
+typedef struct scm_iconv_descriptors scm_t_iconv_descriptors;
+
+struct scm_port_internal
+{
+  scm_t_port_encoding_mode encoding_mode;
+  scm_t_iconv_descriptors *iconv_descriptors;
+};
+
+typedef struct scm_port_internal scm_t_port_internal;
+
+#define SCM_PORT_GET_INTERNAL(x)                                \
+  ((scm_t_port_internal *) (SCM_PTAB_ENTRY(x)->input_cd))
+
+SCM_INTERNAL scm_t_iconv_descriptors *scm_i_port_iconv_descriptors (SCM port);
+
+#endif
diff --git a/libguile/ports.c b/libguile/ports.c
index 8737a76..8f3df9c 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -1,5 +1,5 @@
-/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004,
- *   2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2006,
+ *   2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -55,6 +55,7 @@
 #include "libguile/mallocs.h"
 #include "libguile/validate.h"
 #include "libguile/ports.h"
+#include "libguile/ports-internal.h"
 #include "libguile/vectors.h"
 #include "libguile/weaks.h"
 #include "libguile/fluids.h"
@@ -554,8 +555,8 @@ static void finalize_port (void *, void *);
 static SCM_C_INLINE_KEYWORD void
 register_finalizer_for_port (SCM port)
 {
-  /* Register a finalizer for PORT so that its iconv CDs get freed and
-     optionally its type's `free' function gets called.  */
+  /* Register a finalizer for PORT so that its
+     type's `free' function gets called.  */
   scm_i_set_finalizer (SCM2PTR (port), finalize_port, NULL);
 }
 
@@ -576,8 +577,6 @@ finalize_port (void *ptr, void *data)
        register_finalizer_for_port (port);
       else
        {
-         scm_t_port *entry;
-
          port_type = SCM_TC2PTOBNUM (SCM_CELL_TYPE (port));
          if (port_type >= scm_numptob)
            abort ();
@@ -587,13 +586,6 @@ finalize_port (void *ptr, void *data)
               is for explicit `close-port' by user.  */
            scm_ptobs[port_type].free (port);
 
-         entry = SCM_PTAB_ENTRY (port);
-
-         if (entry->input_cd != (iconv_t) -1)
-           iconv_close (entry->input_cd);
-         if (entry->output_cd != (iconv_t) -1)
-           iconv_close (entry->output_cd);
-
          SCM_SETSTREAM (port, 0);
          SCM_CLR_PORT_OPEN_FLAG (port);
 
@@ -617,8 +609,9 @@ scm_new_port_table_entry (scm_t_bits tag)
    */
   
   SCM z = scm_cons (SCM_EOL, SCM_EOL);
-  scm_t_port *entry = (scm_t_port *) scm_gc_calloc (sizeof (scm_t_port), 
"port");
-  const char *enc;
+  scm_t_port *entry = scm_gc_typed_calloc (scm_t_port);
+  scm_t_port_internal *pti = scm_gc_typed_calloc (scm_t_port_internal);
+  const char *encoding;
 
   entry->file_name = SCM_BOOL_F;
   entry->rw_active = SCM_PORT_NEITHER;
@@ -626,14 +619,20 @@ scm_new_port_table_entry (scm_t_bits tag)
 
   /* Initialize this port with the thread's current default
      encoding.  */
-  enc = scm_i_default_port_encoding ();
-  entry->encoding = enc ? scm_gc_strdup (enc, "port") : NULL;
-
-  /* The conversion descriptors will be opened lazily.  */
-  entry->input_cd = (iconv_t) -1;
-  entry->output_cd = (iconv_t) -1;
-
+  encoding = scm_i_default_port_encoding ();
   entry->ilseq_handler = scm_i_default_port_conversion_handler ();
+  entry->encoding = encoding ? scm_gc_strdup (encoding, "port") : NULL;
+  if (encoding && strcmp (encoding, "UTF-8") == 0)
+    pti->encoding_mode = SCM_PORT_ENCODING_MODE_UTF8;
+  else
+    pti->encoding_mode = SCM_PORT_ENCODING_MODE_ICONV;
+  pti->iconv_descriptors = NULL;
+
+  /* XXX These fields are not what they seem.  They have been
+     repurposed, but cannot safely be renamed in 2.0 without breaking
+     ABI compatibility.  This will be cleaned up in 2.2.  */
+  entry->input_cd = pti;   /* XXX pointer to the internal port structure */
+  entry->output_cd = NULL; /* XXX unused */
 
   SCM_SET_CELL_TYPE (z, tag);
   SCM_SETPTAB_ENTRY (z, entry);
@@ -673,29 +672,27 @@ scm_add_to_port_table (SCM port)
 
 /* Remove a port from the table and destroy it.  */
 
+static void close_iconv_descriptors (scm_t_iconv_descriptors *id);
+
 static void
 scm_i_remove_port (SCM port)
 #define FUNC_NAME "scm_remove_port"
 {
   scm_t_port *p;
+  scm_t_port_internal *pti;
 
   scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
 
   p = SCM_PTAB_ENTRY (port);
+  pti = SCM_PORT_GET_INTERNAL (port);
   scm_port_non_buffer (p);
   p->putback_buf = NULL;
   p->putback_buf_size = 0;
 
-  if (p->input_cd != (iconv_t) -1)
+  if (pti->iconv_descriptors)
     {
-      iconv_close (p->input_cd);
-      p->input_cd = (iconv_t) -1;
-    }
-  
-  if (p->output_cd != (iconv_t) -1)
-    {
-      iconv_close (p->output_cd);
-      p->output_cd = (iconv_t) -1;
+      close_iconv_descriptors (pti->iconv_descriptors);
+      pti->iconv_descriptors = NULL;
     }
 
   SCM_SETPTAB_ENTRY (port, 0);
@@ -1296,13 +1293,13 @@ static int
 get_iconv_codepoint (SCM port, scm_t_wchar *codepoint,
                     char buf[SCM_MBCHAR_BUF_SIZE], size_t *len)
 {
-  scm_t_port *pt;
+  scm_t_iconv_descriptors *id;
   int err, byte_read;
   size_t bytes_consumed, output_size;
   char *output;
   scm_t_uint8 utf8_buf[SCM_MBCHAR_BUF_SIZE];
 
-  pt = SCM_PTAB_ENTRY (port);
+  id = scm_i_port_iconv_descriptors (port);
 
   for (output_size = 0, output = (char *) utf8_buf,
         bytes_consumed = 0, err = 0;
@@ -1332,8 +1329,7 @@ get_iconv_codepoint (SCM port, scm_t_wchar *codepoint,
       input_left = bytes_consumed + 1;
       output_left = sizeof (utf8_buf);
 
-      done = iconv (pt->input_cd, &input, &input_left,
-                   &output, &output_left);
+      done = iconv (id->input_cd, &input, &input_left, &output, &output_left);
       if (done == (size_t) -1)
        {
          err = errno;
@@ -1368,13 +1364,9 @@ get_codepoint (SCM port, scm_t_wchar *codepoint,
 {
   int err;
   scm_t_port *pt = SCM_PTAB_ENTRY (port);
+  scm_t_port_internal *pti = SCM_PORT_GET_INTERNAL (port);
 
-  if (pt->input_cd == (iconv_t) -1)
-    /* Initialize the conversion descriptors, if needed.  */
-    scm_i_set_port_encoding_x (port, pt->encoding);
-
-  /* FIXME: In 2.1, add a flag to determine whether a port is UTF-8.  */
-  if (pt->input_cd == (iconv_t) -1)
+  if (pti->encoding_mode == SCM_PORT_ENCODING_MODE_UTF8)
     err = get_utf8_codepoint (port, codepoint, (scm_t_uint8 *) buf, len);
   else
     err = get_iconv_codepoint (port, codepoint, buf, len);
@@ -2204,71 +2196,143 @@ scm_i_default_port_encoding (void)
     }
 }
 
+static void
+finalize_iconv_descriptors (GC_PTR ptr, GC_PTR data)
+{
+  close_iconv_descriptors (ptr);
+}
+
+static scm_t_iconv_descriptors *
+open_iconv_descriptors (const char *encoding, int reading, int writing)
+{
+  scm_t_iconv_descriptors *id;
+  iconv_t input_cd, output_cd;
+
+  input_cd = (iconv_t) -1;
+  output_cd = (iconv_t) -1;
+  if (reading)
+    {
+      /* Open an input iconv conversion descriptor, from ENCODING
+         to UTF-8.  We choose UTF-8, not UTF-32, because iconv
+         implementations can typically convert from anything to
+         UTF-8, but not to UTF-32 (see
+         
<http://lists.gnu.org/archive/html/bug-libunistring/2010-09/msg00007.html>).  */
+
+      /* Assume opening an iconv descriptor causes about 16 KB of
+         allocation.  */
+      scm_gc_register_allocation (16 * 1024);
+
+      input_cd = iconv_open ("UTF-8", encoding);
+      if (input_cd == (iconv_t) -1)
+        goto invalid_encoding;
+    }
+
+  if (writing)
+    {
+      /* Assume opening an iconv descriptor causes about 16 KB of
+         allocation.  */
+      scm_gc_register_allocation (16 * 1024);
+
+      output_cd = iconv_open (encoding, "UTF-8");
+      if (output_cd == (iconv_t) -1)
+        {
+          if (input_cd != (iconv_t) -1)
+            iconv_close (input_cd);
+          goto invalid_encoding;
+        }
+    }
+
+  id = scm_gc_malloc_pointerless (sizeof (*id), "iconv descriptors");
+  id->input_cd = input_cd;
+  id->output_cd = output_cd;
+
+  /* Register a finalizer to close the descriptors.  */
+  scm_i_set_finalizer (id, finalize_iconv_descriptors, NULL);
+
+  return id;
+
+ invalid_encoding:
+  {
+    SCM err;
+    err = scm_from_locale_string (encoding);
+    scm_misc_error ("open_iconv_descriptors",
+                    "invalid or unknown character encoding ~s",
+                    scm_list_1 (err));
+  }
+}
+
+static void
+close_iconv_descriptors (scm_t_iconv_descriptors *id)
+{
+  if (id->input_cd != (iconv_t) -1)
+    iconv_close (id->input_cd);
+  if (id->output_cd != (iconv_t) -1)
+    iconv_close (id->output_cd);
+  id->input_cd = (void *) -1;
+  id->output_cd = (void *) -1;
+}
+
+scm_t_iconv_descriptors *
+scm_i_port_iconv_descriptors (SCM port)
+{
+  scm_t_port *pt;
+  scm_t_port_internal *pti;
+
+  pt = SCM_PTAB_ENTRY (port);
+  pti = SCM_PORT_GET_INTERNAL (port);
+
+  assert (pti->encoding_mode == SCM_PORT_ENCODING_MODE_ICONV);
+
+  if (!pti->iconv_descriptors)
+    {
+      if (!pt->encoding)
+        pt->encoding = "ISO-8859-1";
+      pti->iconv_descriptors =
+        open_iconv_descriptors (pt->encoding,
+                                SCM_INPUT_PORT_P (port),
+                                SCM_OUTPUT_PORT_P (port));
+    }
+
+  return pti->iconv_descriptors;
+}
+
 void
 scm_i_set_port_encoding_x (SCM port, const char *encoding)
 {
   scm_t_port *pt;
-  iconv_t new_input_cd, new_output_cd;
-
-  new_input_cd = (iconv_t) -1;
-  new_output_cd = (iconv_t) -1;
+  scm_t_port_internal *pti;
+  scm_t_iconv_descriptors *prev;
 
   /* Set the character encoding for this port.  */
   pt = SCM_PTAB_ENTRY (port);
+  pti = SCM_PORT_GET_INTERNAL (port);
+  prev = pti->iconv_descriptors;
 
   if (encoding == NULL)
     encoding = "ISO-8859-1";
 
-  if (pt->encoding != encoding)
-    pt->encoding = scm_gc_strdup (encoding, "port");
-
   /* If ENCODING is UTF-8, then no conversion descriptor is opened
      because we do I/O ourselves.  This saves 100+ KiB for each
      descriptor.  */
-  if (strcmp (encoding, "UTF-8"))
+  if (strcmp (encoding, "UTF-8") == 0)
     {
-      if (SCM_CELL_WORD_0 (port) & SCM_RDNG)
-       {
-         /* Open an input iconv conversion descriptor, from ENCODING
-            to UTF-8.  We choose UTF-8, not UTF-32, because iconv
-            implementations can typically convert from anything to
-            UTF-8, but not to UTF-32 (see
-            
<http://lists.gnu.org/archive/html/bug-libunistring/2010-09/msg00007.html>).  */
-         new_input_cd = iconv_open ("UTF-8", encoding);
-         if (new_input_cd == (iconv_t) -1)
-           goto invalid_encoding;
-       }
-
-      if (SCM_CELL_WORD_0 (port) & SCM_WRTNG)
-       {
-         new_output_cd = iconv_open (encoding, "UTF-8");
-         if (new_output_cd == (iconv_t) -1)
-           {
-             if (new_input_cd != (iconv_t) -1)
-               iconv_close (new_input_cd);
-             goto invalid_encoding;
-           }
-       }
+      pt->encoding = "UTF-8";
+      pti->encoding_mode = SCM_PORT_ENCODING_MODE_UTF8;
+      pti->iconv_descriptors = NULL;
+    }
+  else
+    {
+      /* Open descriptors before mutating the port. */
+      pti->iconv_descriptors =
+        open_iconv_descriptors (encoding,
+                                SCM_INPUT_PORT_P (port),
+                                SCM_OUTPUT_PORT_P (port));
+      pt->encoding = scm_gc_strdup (encoding, "port");
+      pti->encoding_mode = SCM_PORT_ENCODING_MODE_ICONV;
     }
 
-  if (pt->input_cd != (iconv_t) -1)
-    iconv_close (pt->input_cd);
-  if (pt->output_cd != (iconv_t) -1)
-    iconv_close (pt->output_cd);
-
-  pt->input_cd = new_input_cd;
-  pt->output_cd = new_output_cd;
-
-  return;
-
- invalid_encoding:
-  {
-    SCM err;
-    err = scm_from_locale_string (encoding);
-    scm_misc_error ("scm_i_set_port_encoding_x",
-                   "invalid or unknown character encoding ~s",
-                   scm_list_1 (err));
-  }
+  if (prev)
+    close_iconv_descriptors (prev);
 }
 
 SCM_DEFINE (scm_port_encoding, "port-encoding", 1, 0, 0,
diff --git a/libguile/ports.h b/libguile/ports.h
index d4d59b7..95545cd 100644
--- a/libguile/ports.h
+++ b/libguile/ports.h
@@ -3,8 +3,8 @@
 #ifndef SCM_PORTS_H
 #define SCM_PORTS_H
 
-/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004,
- *   2006, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2006,
+ *   2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -112,9 +112,22 @@ typedef struct
   unsigned char *putback_buf;
   size_t putback_buf_size;        /* allocated size of putback_buf.  */
 
-  /* input/output iconv conversion descriptors */
-  void *input_cd;
-  void *output_cd;
+  /* IMPORTANT: 'input_cd' and 'output_cd' used to be pointers to the
+     input and output iconv descriptors, but those have been moved to
+     the internal-only port structure defined in ports-internal.h.
+
+     Given that we must preserve ABI compatibility in 2.0, we cannot
+     safely change this public structure without running afoul of C
+     strict aliasing rules.  We cannot even change the member names.
+
+     To work around this, in this public structure, 'input_cd' has been
+     repurposed to be a pointer to the internal port structure (see
+     ports-internal.h), and 'output_cd' is now unused.
+
+     This will be cleaned up in 2.2.  */
+
+  void *input_cd;   /* XXX actually a pointer to scm_t_port_internal */
+  void *output_cd;  /* XXX actually unused */
 } scm_t_port;
 
 
diff --git a/libguile/print.c b/libguile/print.c
index 647eed8..1572690 100644
--- a/libguile/print.c
+++ b/libguile/print.c
@@ -1,5 +1,5 @@
 /* Copyright (C) 1995-1999, 2000, 2001, 2002, 2003, 2004, 2006, 2008,
- *   2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+ *   2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -45,6 +45,7 @@
 #include "libguile/alist.h"
 #include "libguile/struct.h"
 #include "libguile/ports.h"
+#include "libguile/ports-internal.h"
 #include "libguile/root.h"
 #include "libguile/strings.h"
 #include "libguile/strports.h"
@@ -879,9 +880,9 @@ display_string_using_iconv (const void *str, int narrow_p, 
size_t len,
                            scm_t_string_failed_conversion_handler strategy)
 {
   size_t printed;
-  scm_t_port *pt;
+  scm_t_iconv_descriptors *id;
 
-  pt = SCM_PTAB_ENTRY (port);
+  id = scm_i_port_iconv_descriptors (port);
 
   printed = 0;
 
@@ -910,7 +911,7 @@ display_string_using_iconv (const void *str, int narrow_p, 
size_t len,
       output = encoded_output;
       output_left = sizeof (encoded_output);
 
-      done = iconv (pt->output_cd, &input, &input_left,
+      done = iconv (id->output_cd, &input, &input_left,
                    &output, &output_left);
 
       output_len = sizeof (encoded_output) - output_left;
@@ -920,7 +921,7 @@ display_string_using_iconv (const void *str, int narrow_p, 
size_t len,
           int errno_save = errno;
 
          /* Reset the `iconv' state.  */
-         iconv (pt->output_cd, NULL, NULL, NULL, NULL);
+         iconv (id->output_cd, NULL, NULL, NULL, NULL);
 
          /* Print the OUTPUT_LEN bytes successfully converted.  */
          scm_lfwrite (encoded_output, output_len, port);
@@ -980,16 +981,11 @@ display_string (const void *str, int narrow_p,
                scm_t_string_failed_conversion_handler strategy)
 
 {
-  scm_t_port *pt;
+  scm_t_port_internal *pti;
 
-  pt = SCM_PTAB_ENTRY (port);
+  pti = SCM_PORT_GET_INTERNAL (port);
 
-  if (pt->output_cd == (iconv_t) -1)
-    /* Initialize the conversion descriptors, if needed.  */
-    scm_i_set_port_encoding_x (port, pt->encoding);
-
-  /* FIXME: In 2.1, add a flag to determine whether a port is UTF-8.  */
-  if (pt->output_cd == (iconv_t) -1)
+  if (pti->encoding_mode == SCM_PORT_ENCODING_MODE_UTF8)
     return display_string_as_utf8 (str, narrow_p, len, port);
   else
     return display_string_using_iconv (str, narrow_p, len,


hooks/post-receive
-- 
GNU Guile