# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1636499444 -3600
# Node ID 74b4f0b3d1d967dcb80e8d945290e2161f90010b
# Parent  db49ed1bde3b16fa9a00de619aeba54c5c53043f
Added trailing data type sizes to object tables.

diff -r db49ed1bde3b -r 74b4f0b3d1d9 generator.py
--- a/generator.py	Tue Nov 09 22:11:58 2021 +0100
+++ b/generator.py	Wed Nov 10 00:10:44 2021 +0100
@@ -278,7 +278,8 @@
 
                 table = []
                 self.populate_table(Reference(kind, path), table)
-                self.write_table(f_decls, f_defs, table_name, structure_size, table)
+                self.write_table(f_decls, f_defs, table_name, structure_size, table,
+                                 self.get_trailing_data_type(Reference(kind, path)))
 
             # Generate function instances.
 
@@ -770,14 +771,20 @@
                 f_consts.write("    %s = %d" % (pos_encoder(attrname), i))
         print >>f_consts, "\n    };"
 
-    def write_table(self, f_decls, f_defs, table_name, structure_size, table):
+    def write_table(self, f_decls, f_defs, table_name, structure_size, table,
+                    trailing_data_type):
 
         """
         Write the declarations to 'f_decls' and definitions to 'f_defs' for
         the object having the given 'table_name' and the given 'structure_size',
         with 'table' details used to populate the definition.
+
+        To support value copying, the trailing data size is also written if
+        'trailing_data_type' is defined.
         """
 
+        trailing_size = trailing_data_type and "sizeof(%s)" % trailing_data_type or "0"
+
         print >>f_decls, "extern const __table %s;\n" % table_name
 
         # Write the corresponding definition.
@@ -785,11 +792,12 @@
         print >>f_defs, """\
 const __table %s = {
     %s,
+    %s,
     {
         %s
     }
 };
-""" % (table_name, structure_size,
+""" % (table_name, structure_size, trailing_size,
        ",\n        ".join(table))
 
     def write_parameter_table(self, f_decls, f_defs, table_name, min_parameters,
@@ -1141,13 +1149,24 @@
         the 'attrs' mapping, adding entries to the 'trailing' member collection.
         """
 
+        if self.get_trailing_data_type(ref):
+            trailing.append(encode_literal_constant_value(attrs["__trailing__"]))
+
+    def get_trailing_data_type(self, ref):
+
+        """
+        For the structure having the given 'ref', return the type of any
+        trailing data.
+        """
+
         structure_ref = self.get_target_structure(ref)
 
         # Instances with trailing data.
 
-        if structure_ref.get_kind() == "<instance>" and \
-           structure_ref.get_origin() in self.trailing_data_types:
-            trailing.append(encode_literal_constant_value(attrs["__trailing__"]))
+        if structure_ref.get_kind() == "<instance>":
+            return self.trailing_data_types.get(structure_ref.get_origin())
+        else:
+            return None
 
     def get_target_structure(self, ref):
 
diff -r db49ed1bde3b -r 74b4f0b3d1d9 templates/types.h
--- a/templates/types.h	Tue Nov 09 22:11:58 2021 +0100
+++ b/templates/types.h	Wed Nov 10 00:10:44 2021 +0100
@@ -42,6 +42,7 @@
 typedef struct __table
 {
     const __pos size;
+    const size_t trailing_size;
     const __code attrs[];
 } __table;
 
@@ -120,7 +121,7 @@
 
 } __obj;
 
-#define __INSTANCE_SIZE(NUMBER) ((NUMBER) * sizeof(__attr) + sizeof(__table *) + sizeof(__ppos))
+#define __INSTANCE_SIZE(REF) ((REF)->table->size * sizeof(__attr) + sizeof(__table *) + sizeof(__ppos) + (REF)->table->trailing_size)
 
 /* Fragments are simple collections of attributes employed by sequence types.
    They provide the basis of lists and tuples. */