1.1 --- a/generator.py	Tue Nov 09 22:11:58 2021 +0100
     1.2 +++ b/generator.py	Wed Nov 10 00:10:44 2021 +0100
     1.3 @@ -278,7 +278,8 @@
     1.4  
     1.5                  table = []
     1.6                  self.populate_table(Reference(kind, path), table)
     1.7 -                self.write_table(f_decls, f_defs, table_name, structure_size, table)
     1.8 +                self.write_table(f_decls, f_defs, table_name, structure_size, table,
     1.9 +                                 self.get_trailing_data_type(Reference(kind, path)))
    1.10  
    1.11              # Generate function instances.
    1.12  
    1.13 @@ -770,14 +771,20 @@
    1.14                  f_consts.write("    %s = %d" % (pos_encoder(attrname), i))
    1.15          print >>f_consts, "\n    };"
    1.16  
    1.17 -    def write_table(self, f_decls, f_defs, table_name, structure_size, table):
    1.18 +    def write_table(self, f_decls, f_defs, table_name, structure_size, table,
    1.19 +                    trailing_data_type):
    1.20  
    1.21          """
    1.22          Write the declarations to 'f_decls' and definitions to 'f_defs' for
    1.23          the object having the given 'table_name' and the given 'structure_size',
    1.24          with 'table' details used to populate the definition.
    1.25 +
    1.26 +        To support value copying, the trailing data size is also written if
    1.27 +        'trailing_data_type' is defined.
    1.28          """
    1.29  
    1.30 +        trailing_size = trailing_data_type and "sizeof(%s)" % trailing_data_type or "0"
    1.31 +
    1.32          print >>f_decls, "extern const __table %s;\n" % table_name
    1.33  
    1.34          # Write the corresponding definition.
    1.35 @@ -785,11 +792,12 @@
    1.36          print >>f_defs, """\
    1.37  const __table %s = {
    1.38      %s,
    1.39 +    %s,
    1.40      {
    1.41          %s
    1.42      }
    1.43  };
    1.44 -""" % (table_name, structure_size,
    1.45 +""" % (table_name, structure_size, trailing_size,
    1.46         ",\n        ".join(table))
    1.47  
    1.48      def write_parameter_table(self, f_decls, f_defs, table_name, min_parameters,
    1.49 @@ -1141,13 +1149,24 @@
    1.50          the 'attrs' mapping, adding entries to the 'trailing' member collection.
    1.51          """
    1.52  
    1.53 +        if self.get_trailing_data_type(ref):
    1.54 +            trailing.append(encode_literal_constant_value(attrs["__trailing__"]))
    1.55 +
    1.56 +    def get_trailing_data_type(self, ref):
    1.57 +
    1.58 +        """
    1.59 +        For the structure having the given 'ref', return the type of any
    1.60 +        trailing data.
    1.61 +        """
    1.62 +
    1.63          structure_ref = self.get_target_structure(ref)
    1.64  
    1.65          # Instances with trailing data.
    1.66  
    1.67 -        if structure_ref.get_kind() == "<instance>" and \
    1.68 -           structure_ref.get_origin() in self.trailing_data_types:
    1.69 -            trailing.append(encode_literal_constant_value(attrs["__trailing__"]))
    1.70 +        if structure_ref.get_kind() == "<instance>":
    1.71 +            return self.trailing_data_types.get(structure_ref.get_origin())
    1.72 +        else:
    1.73 +            return None
    1.74  
    1.75      def get_target_structure(self, ref):
    1.76  

     2.1 --- a/templates/types.h	Tue Nov 09 22:11:58 2021 +0100
     2.2 +++ b/templates/types.h	Wed Nov 10 00:10:44 2021 +0100
     2.3 @@ -42,6 +42,7 @@
     2.4  typedef struct __table
     2.5  {
     2.6      const __pos size;
     2.7 +    const size_t trailing_size;
     2.8      const __code attrs[];
     2.9  } __table;
    2.10  
    2.11 @@ -120,7 +121,7 @@
    2.12  
    2.13  } __obj;
    2.14  
    2.15 -#define __INSTANCE_SIZE(NUMBER) ((NUMBER) * sizeof(__attr) + sizeof(__table *) + sizeof(__ppos))
    2.16 +#define __INSTANCE_SIZE(REF) ((REF)->table->size * sizeof(__attr) + sizeof(__table *) + sizeof(__ppos) + (REF)->table->trailing_size)
    2.17  
    2.18  /* Fragments are simple collections of attributes employed by sequence types.
    2.19     They provide the basis of lists and tuples. */