Implement final on class.

* class.c (check_bases): Diagnose derivation from a final class.
	* cp-tree.h (lang_type_class): Add is_final and adjust dummy.
	(CLASSTYPE_FINAL): New.
	* parser.c (cp_parser_class_head): Parse class-virt-specifier, set
	CLASSTYPE_FINAL.
	* pt.c (instantiate_class_template_1): Copy CLASSTYPE_FINAL.

From-SVN: r173761
This commit is contained in:
Ville Voutilainen 2011-05-14 21:13:23 +03:00 committed by Jason Merrill
parent ade2e40389
commit 486d481b39
8 changed files with 93 additions and 4 deletions

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@ -1,3 +1,13 @@
2011-05-13 Ville Voutilainen <ville.voutilainen@gmail.com>
Implement final on class.
* class.c (check_bases): Diagnose derivation from a final class.
* cp-tree.h (lang_type_class): Add is_final and adjust dummy.
(CLASSTYPE_FINAL): New.
* parser.c (cp_parser_class_head): Parse class-virt-specifier, set
CLASSTYPE_FINAL.
* pt.c (instantiate_class_template_1): Copy CLASSTYPE_FINAL.
2011-05-13 Jason Merrill <jason@redhat.com>
PR c++/48969

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@ -1268,6 +1268,10 @@ check_bases (tree t,
gcc_assert (COMPLETE_TYPE_P (basetype));
if (CLASSTYPE_FINAL (basetype))
error ("cannot derive from %<final%> base %qT in derived type %qT",
basetype, t);
/* If any base class is non-literal, so is the derived class. */
if (!CLASSTYPE_LITERAL_P (basetype))
CLASSTYPE_LITERAL_P (t) = false;

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@ -1322,6 +1322,7 @@ struct GTY(()) lang_type_class {
unsigned has_complex_move_ctor : 1;
unsigned has_complex_move_assign : 1;
unsigned has_constexpr_ctor : 1;
unsigned is_final : 1;
/* When adding a flag here, consider whether or not it ought to
apply to a template instance if it applies to the template. If
@ -1330,7 +1331,7 @@ struct GTY(()) lang_type_class {
/* There are some bits left to fill out a 32-bit word. Keep track
of this by updating the size of this bitfield whenever you add or
remove a flag. */
unsigned dummy : 3;
unsigned dummy : 2;
tree primary_base;
VEC(tree_pair_s,gc) *vcall_indices;
@ -1438,6 +1439,11 @@ struct GTY((variable_size)) lang_type {
#define CLASSTYPE_LAZY_DESTRUCTOR(NODE) \
(LANG_TYPE_CLASS_CHECK (NODE)->lazy_destructor)
/* Nonzero means that NODE (a class type) is final */
#define CLASSTYPE_FINAL(NODE) \
(LANG_TYPE_CLASS_CHECK (NODE)->is_final)
/* Nonzero means that this _CLASSTYPE node overloads operator=(X&). */
#define TYPE_HAS_COPY_ASSIGN(NODE) (LANG_TYPE_CLASS_CHECK (NODE)->has_copy_assign)

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@ -17082,10 +17082,13 @@ cp_parser_class_specifier (cp_parser* parser)
class-head:
class-key identifier [opt] base-clause [opt]
class-key nested-name-specifier identifier base-clause [opt]
class-key nested-name-specifier identifier class-virt-specifier [opt] base-clause [opt]
class-key nested-name-specifier [opt] template-id
base-clause [opt]
class-virt-specifier:
final
GNU Extensions:
class-key attributes identifier [opt] base-clause [opt]
class-key attributes nested-name-specifier identifier base-clause [opt]
@ -17117,6 +17120,7 @@ cp_parser_class_head (cp_parser* parser,
tree id = NULL_TREE;
tree type = NULL_TREE;
tree attributes;
cp_virt_specifiers virt_specifiers = VIRT_SPEC_UNSPECIFIED;
bool template_id_p = false;
bool qualified_p = false;
bool invalid_nested_name_p = false;
@ -17260,8 +17264,11 @@ cp_parser_class_head (cp_parser* parser,
pop_deferring_access_checks ();
if (id)
cp_parser_check_for_invalid_template_id (parser, id,
type_start_token->location);
{
cp_parser_check_for_invalid_template_id (parser, id,
type_start_token->location);
virt_specifiers = cp_parser_virt_specifier_seq_opt (parser);
}
/* If it's not a `:' or a `{' then we can't really be looking at a
class-head, since a class-head only appears as part of a
@ -17277,6 +17284,13 @@ cp_parser_class_head (cp_parser* parser,
/* At this point, we're going ahead with the class-specifier, even
if some other problem occurs. */
cp_parser_commit_to_tentative_parse (parser);
if (virt_specifiers & VIRT_SPEC_OVERRIDE)
{
cp_parser_error (parser,
"cannot specify %<override%> for a class");
type = error_mark_node;
goto out;
}
/* Issue the error about the overly-qualified name now. */
if (qualified_p)
{
@ -17493,6 +17507,8 @@ cp_parser_class_head (cp_parser* parser,
if (type)
DECL_SOURCE_LOCATION (TYPE_NAME (type)) = type_start_token->location;
*attributes_p = attributes;
if (type && (virt_specifiers & VIRT_SPEC_FINAL))
CLASSTYPE_FINAL (type) = 1;
out:
parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p;
return type;

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@ -8209,6 +8209,7 @@ instantiate_class_template_1 (tree type)
CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
}
CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
pbinfo = TYPE_BINFO (pattern);

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@ -1,3 +1,8 @@
2011-05-13 Ville Voutilainen <ville.voutilainen@gmail.com>
* g++.dg/cpp0x/override1.C: Move from inherit/virtual9.C.
* g++.dg/cpp0x/override2.C: New.
2011-05-14 Tobias Burnus <burnus@net-b.de>
PR fortran/18918

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@ -0,0 +1,47 @@
// { dg-do compile }
// { dg-options "--std=c++0x" }
struct B1 {};
struct B2 final {};
struct D1 : B1 {};
struct D2 : B2 {}; // { dg-error "cannot derive from 'final' base" }
template<class T> struct D3 : T {};
template<class T> struct D4 : T {}; // { dg-error "cannot derive from 'final' base" }
template <class T> struct B3 {};
template <class T> struct B4 final {};
template <class T> struct B5 final {};
struct undeclared<int> final { }; // { dg-error "not a template" }
struct D5 : B3<D5> {};
struct D6 : B4<D6> {}; // { dg-error "cannot derive from 'final' base" }
struct B6 final final {}; // { dg-error "duplicate virt-specifier" }
struct B7 override {}; // { dg-error "cannot specify 'override' for a class" }
int main()
{
D3<B1> d;
D4<B2> d2;
struct B2 final{}; // { dg-error "previous definition" }
B2 final; // { dg-error "has a previous declaration|previously declared here" }
B2 final2 = final;
struct B2 {}; // { dg-error "redefinition" }
struct B2 final; // { dg-error "redeclaration" }
struct B2 override; // { dg-error "previously declared here" }
struct B2 final {}; // { dg-error "redefinition" }
struct B2 override {}; // { dg-error "cannot specify 'override' for a class" }
B2 override{}; // { dg-error "redeclaration" }
struct foo final {}; // { dg-error "previous definition" }
struct foo final {}; // { dg-error "redefinition" }
foo final; // { dg-error "conflicting declaration" }
}