Ticket #407: tt407-post1.0-pf-logic.patch

src/packfile.c

@@ -954 +954 @@
         return 0;
     }
 
-    /* Ensure the bytecode version is one we can read. Currently, we only
-     * support bytecode versions matching the current one.
+    /* Ensure the bytecode version is one we can read. pre-1.0 we only
+     * supported bytecode versions matching the current one.
+     * From 1.0 on we at least try to read older pbc's because we
+     * changed our pmc and ops renumbering policy, but removed pmc/ops are
+     * unsupported.
      *
-     * tools/dev/pbc_header.pl --upd t/native_pbc/ *.pbc
-     * stamps version and fingerprint in the native tests. */
+     * With tools/dev/pbc_header.pl --upd t/native_pbc/ *.pbc
+     * we can update the parrot version and fingerprint in the native tests */
     if (header->bc_major != PARROT_PBC_MAJOR
     ||  header->bc_minor != PARROT_PBC_MINOR) {
-        Parrot_io_eprintf(NULL, "PackFile_unpack: This Parrot cannot read "
-            "bytecode files with version %d.%d.\n",
-            header->bc_major, header->bc_minor);
-        if (!(self->options & PFOPT_UTILS))
+        const char *failmsg = "PackFile_unpack: This Parrot cannot read "
+            "bytecode files %s version %d.%d.\n";
+        if (header->major < 1) {
+            Parrot_io_eprintf(NULL, failmsg, "with",
+                              header->bc_major, header->bc_minor);
             return 0;
+        }
+        else {
+            if (header->bc_major << 0xff + header->bc_minor
+                > PARROT_PBC_MAJOR << 0xff + PARROT_PBC_MINOR) {
+                Parrot_io_eprintf(NULL, failmsg, "newer than",
+                                  PARROT_PBC_MAJOR, PARROT_PBC_MINOR);
+                return 0;
+            }
+            /* Read older, but refuse to read pre-1.0 bytecode as the
+             * pmc and ops numbering changed randomly. post-1.0 the
+             * earlier ops and pmc indices are kept.
+             * See F<lib/Parrot/OpsRenumber.pm>
+             */
+            if (header->bc_major << 0xff + header->bc_minor < 338) {
+                Parrot_io_eprintf(NULL, failmsg, "older than", 3, 38);
+                return 0;
+            }
+        }
     }
 
     /* Check wordsize, byte order and floating point number type are valid. */