bump objcode version to 2.0; introduce minor-version compatibility

* libguile/_scm.h (SCM_OBJCODE_MAJOR_VERSION): Bump to 2.
  (SCM_OBJCODE_MINOR_VERSION): Reset to 0.
  (SCM_OBJCODE_MACHINE_VERSION_STRING, SCM_OBJCODE_COOKIE): Reorder so
  the minor version is the last byte.

* libguile/objcodes.c (make_objcode_by_mmap): Accept objcodes whose
  minor version is less than SCM_OBJCODE_MINOR_VERSION, not just equal
  to.

diff --git a/libguile/_scm.h b/libguile/_scm.h
index 5421116..2842130 100644 (file)
--- a/libguile/_scm.h
+++ b/libguile/_scm.h
@@ -3,7 +3,7 @@
 #ifndef SCM__SCM_H
 #define SCM__SCM_H
 
-/* Copyright (C) 1995,1996,2000,2001, 2002, 2006, 2008, 2009, 2010 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,2000,2001, 2002, 2006, 2008, 2009, 2010, 2011 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
@@ -205,8 +205,8 @@
 #define SCM_OBJCODE_WORD_SIZE  SCM_CPP_STRINGIFY (SIZEOF_VOID_P)
 
 /* Major and minor versions must be single characters. */
-#define SCM_OBJCODE_MAJOR_VERSION 0
-#define SCM_OBJCODE_MINOR_VERSION T
+#define SCM_OBJCODE_MAJOR_VERSION 2
+#define SCM_OBJCODE_MINOR_VERSION 0
 #define SCM_OBJCODE_MAJOR_VERSION_STRING        \
   SCM_CPP_STRINGIFY(SCM_OBJCODE_MAJOR_VERSION)
 #define SCM_OBJCODE_MINOR_VERSION_STRING        \
@@ -214,11 +214,11 @@
 #define SCM_OBJCODE_VERSION_STRING                                      \
   SCM_OBJCODE_MAJOR_VERSION_STRING "." SCM_OBJCODE_MINOR_VERSION_STRING
 #define SCM_OBJCODE_MACHINE_VERSION_STRING                              \
-  SCM_OBJCODE_VERSION_STRING "-" SCM_OBJCODE_ENDIANNESS "-" SCM_OBJCODE_WORD_SIZE
+  SCM_OBJCODE_ENDIANNESS "-" SCM_OBJCODE_WORD_SIZE "-" SCM_OBJCODE_VERSION_STRING
 
 /* The objcode magic header.  */
 #define SCM_OBJCODE_COOKIE                              \
-  "GOOF-" SCM_OBJCODE_MACHINE_VERSION_STRING "---"
+  "GOOF----" SCM_OBJCODE_MACHINE_VERSION_STRING
 
 #endif  /* SCM__SCM_H */
 

diff --git a/libguile/objcodes.c b/libguile/objcodes.c
index b7aa578..f4e20f8 100644 (file)
--- a/libguile/objcodes.c
+++ b/libguile/objcodes.c
@@ -77,7 +77,13 @@ make_objcode_by_mmap (int fd)
       SCM_SYSERROR;
     }
 
-  if (memcmp (addr, SCM_OBJCODE_COOKIE, strlen (SCM_OBJCODE_COOKIE)))
+  /* The cookie ends with a version of the form M.N, where M is the
+     major version and N is the minor version.  For this Guile to be
+     able to load an objcode, M must be SCM_OBJCODE_MAJOR_VERSION, and N
+     must be less than or equal to SCM_OBJCODE_MINOR_VERSION.  Since N
+     is the last character, we do a strict comparison on all but the
+     last, then a <= on the last one.  */
+  if (memcmp (addr, SCM_OBJCODE_COOKIE, strlen (SCM_OBJCODE_COOKIE) - 1))
     {
       SCM args = scm_list_1 (scm_from_latin1_stringn
                              (addr, strlen (SCM_OBJCODE_COOKIE)));
@@ -86,6 +92,16 @@ make_objcode_by_mmap (int fd)
       scm_misc_error (FUNC_NAME, "bad header on object file: ~s", args);
     }
 
+  {
+    char minor_version = addr[strlen (SCM_OBJCODE_COOKIE) - 1];
+
+    if (minor_version > SCM_OBJCODE_MINOR_VERSION_STRING[0])
+      scm_misc_error (FUNC_NAME, "objcode minor version too new (~a > ~a)",
+                      scm_list_2 (scm_from_latin1_stringn (&minor_version, 1),
+                                  scm_from_latin1_string
+                                  (SCM_OBJCODE_MINOR_VERSION_STRING)));
+  }
+
   data = (struct scm_objcode*)(addr + strlen (SCM_OBJCODE_COOKIE));
 
   if (data->len + data->metalen != (st.st_size - sizeof (*data) - strlen (SCM_OBJCODE_COOKIE)))