[PATCH] C++0x, virt-specifier (final/override) support for member functions (parser and analysis both)
Ville Voutilainen
ville.voutilainen@gmail.com
Sun May 8 02:19:00 GMT 2011
Tested on Linux/X86-32. Final on class is not yet supported,
that's probably what I'll be working on next. Changelog and
patch follow. Please holler if anything's wrong, as far as
I can see this works as it's supposed to.
2011-05-08 Ville Voutilainen <ville.voutilainen@gmail.com> <ville.voutilainen@symbio.com>
Implement final/override for member functions.
* class.c (check_for_override): Check for DECL_OVERRIDE_P if the fndecl doesn't override anything and diagnose.
* cp-tree.h: Add DECL_OVERRIDE_P and DECL_FINAL_P, add a new typedef cp_virt_specifiers, use cp_virt_specifiers in cp_declarator.
* decl.c (set_virt_specifiers): New. Used for setting the virt-specifiers from cp_declarator to DECL_OVERRIDE_P and DECL_FINAL_P.
* decl.c (grokdeclarator): ..and use them here. Diagnose virt-specifiers on non-fields here.
* parser.c (make_call_declarator): add the virt-specifiers as a new parameter.
* parser.c (cp_parser_lambda_declarator_opt, cp_parser_direct_declarator): ..and change the calls to make_call_declarator
* parser.c (cp_parser_virt_specifier_seq_opt): New. Parses a virt-specifier-seq for a member function.
* search.c (check_final_overrider): Diagnose attempts to override a final member function.
* virtual9.C: New. Tests for virt-specifiers.
* tree.h: Convert the #defines for cv-qualifier values into an enum, add a new enum for virt-specifier values.
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 9af238b..0c42281 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -2477,6 +2477,11 @@ check_for_override (tree decl, tree ctype)
if (DECL_DESTRUCTOR_P (decl))
TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype) = true;
}
+ else if (DECL_OVERRIDE_P (decl))
+ {
+ DECL_VINDEX (decl) = error_mark_node;
+ error ("%q+#D marked override, but does not override", decl);
+ }
}
/* Warn about hidden virtual functions that are not overridden in t.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index a65998d..b729a3c 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -73,6 +73,7 @@ c-common.h, not after.
LAMBDA_EXPR_CAPTURES_THIS_P (in LAMBDA_EXPR)
DECLTYPE_FOR_LAMBDA_CAPTURE (in DECLTYPE_TYPE)
VEC_INIT_EXPR_IS_CONSTEXPR (in VEC_INIT_EXPR)
+ DECL_OVERRIDE_P (in FUNCTION_DECL)
1: IDENTIFIER_VIRTUAL_P (in IDENTIFIER_NODE)
TI_PENDING_TEMPLATE_FLAG.
TEMPLATE_PARMS_FOR_INLINE.
@@ -85,6 +86,7 @@ c-common.h, not after.
TARGET_EXPR_LIST_INIT_P (in TARGET_EXPR)
LAMBDA_EXPR_MUTABLE_P (in LAMBDA_EXPR)
DECLTYPE_FOR_LAMBDA_RETURN (in DECLTYPE_TYPE)
+ DECL_FINAL_P (in FUNCTION_DECL)
2: IDENTIFIER_OPNAME_P (in IDENTIFIER_NODE)
ICS_THIS_FLAG (in _CONV)
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (in VAR_DECL)
@@ -2285,6 +2287,15 @@ struct GTY((variable_size)) lang_decl {
#define DECL_INVALID_OVERRIDER_P(NODE) \
(DECL_LANG_FLAG_4 (NODE))
+/* True (in a FUNCTION_DECL) if NODE is a function declared with
+ an override virt-specifier */
+#define DECL_OVERRIDE_P(NODE) (TREE_LANG_FLAG_0 (NODE))
+
+/* True (in a FUNCTION_DECL) if NODE is a function declared with
+ a final virt-specifier */
+#define DECL_FINAL_P(NODE) (TREE_LANG_FLAG_1 (NODE))
+
+
/* The thunks associated with NODE, a FUNCTION_DECL. */
#define DECL_THUNKS(NODE) \
(LANG_DECL_FN_CHECK (NODE)->context)
@@ -4426,6 +4437,11 @@ extern GTY(()) operator_name_info_t assignment_operator_name_info
typedef int cp_cv_quals;
+/* A type-qualifier, or bitmask therefore, using the VIRT_SPEC
+ constants. */
+
+typedef int cp_virt_specifiers;
+
/* A storage class. */
typedef enum cp_storage_class {
@@ -4568,6 +4584,8 @@ struct cp_declarator {
tree parameters;
/* The cv-qualifiers for the function. */
cp_cv_quals qualifiers;
+ /* The virt-specifiers for the function. */
+ cp_virt_specifiers virt_specifiers;
/* The exception-specification for the function. */
tree exception_specification;
/* The late-specified return type, if any. */
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 5bf637e..4593244 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7283,6 +7283,24 @@ grokfndecl (tree ctype,
return decl;
}
+/* decl is a FUNCTION_DECL.
+ specifiers are the parsed virt-specifiers.
+
+ Set flags to reflect the virt-specifiers.
+
+ Returns decl. */
+
+static tree set_virt_specifiers (tree decl, cp_virt_specifiers specifiers)
+{
+ if (decl == NULL_TREE)
+ return decl;
+ if (specifiers & VIRT_SPEC_OVERRIDE)
+ DECL_OVERRIDE_P (decl) = 1;
+ if (specifiers & VIRT_SPEC_FINAL)
+ DECL_FINAL_P (decl) = 1;
+ return decl;
+}
+
/* DECL is a VAR_DECL for a static data member. Set flags to reflect
the linkage that DECL will receive in the object file. */
@@ -8057,6 +8075,9 @@ grokdeclarator (const cp_declarator *declarator,
/* cv-qualifiers that apply to the declarator, for a declaration of
a member function. */
cp_cv_quals memfn_quals = TYPE_UNQUALIFIED;
+ /* virt-specifiers that apply to the declarator, for a declaration of
+ a member function. */
+ cp_virt_specifiers virt_specifiers = VIRT_SPEC_UNSPECIFIED;
/* cv-qualifiers that apply to the type specified by the DECLSPECS. */
int type_quals;
tree raises = NULL_TREE;
@@ -8817,7 +8838,8 @@ grokdeclarator (const cp_declarator *declarator,
/* Pick up type qualifiers which should be applied to `this'. */
memfn_quals = declarator->u.function.qualifiers;
-
+ /* Pick up virt-specifiers. */
+ virt_specifiers = declarator->u.function.virt_specifiers;
/* Pick up the exception specifications. */
raises = declarator->u.function.exception_specification;
@@ -9742,6 +9764,7 @@ grokdeclarator (const cp_declarator *declarator,
sfk,
funcdef_flag, template_count, in_namespace,
attrlist, declarator->id_loc);
+ decl = set_virt_specifiers (decl, virt_specifiers);
if (decl == NULL_TREE)
return error_mark_node;
#if 0
@@ -9935,6 +9958,8 @@ grokdeclarator (const cp_declarator *declarator,
else if (thread_p)
error ("storage class %<__thread%> invalid for function %qs", name);
+ if (virt_specifiers)
+ error ("virt-specifiers in %qs not allowed outside a class definition", name);
/* Function declaration not at top level.
Storage classes other than `extern' are not allowed
and `extern' makes no difference. */
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 89100aa..6dcbe20 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -937,7 +937,7 @@ clear_decl_specs (cp_decl_specifier_seq *decl_specs)
VAR_DECLs or FUNCTION_DECLs) should do that directly. */
static cp_declarator *make_call_declarator
- (cp_declarator *, tree, cp_cv_quals, tree, tree);
+ (cp_declarator *, tree, cp_cv_quals, cp_virt_specifiers, tree, tree);
static cp_declarator *make_array_declarator
(cp_declarator *, tree);
static cp_declarator *make_pointer_declarator
@@ -1102,6 +1102,7 @@ cp_declarator *
make_call_declarator (cp_declarator *target,
tree parms,
cp_cv_quals cv_qualifiers,
+ cp_virt_specifiers virt_specifiers,
tree exception_specification,
tree late_return_type)
{
@@ -1111,6 +1112,7 @@ make_call_declarator (cp_declarator *target,
declarator->declarator = target;
declarator->u.function.parameters = parms;
declarator->u.function.qualifiers = cv_qualifiers;
+ declarator->u.function.virt_specifiers = virt_specifiers;
declarator->u.function.exception_specification = exception_specification;
declarator->u.function.late_return_type = late_return_type;
if (target)
@@ -1690,6 +1692,8 @@ static enum tree_code cp_parser_ptr_operator
(cp_parser *, tree *, cp_cv_quals *);
static cp_cv_quals cp_parser_cv_qualifier_seq_opt
(cp_parser *);
+static cp_virt_specifiers cp_parser_virt_specifier_seq_opt
+ (cp_parser *);
static tree cp_parser_late_return_type_opt
(cp_parser *);
static tree cp_parser_declarator_id
@@ -7664,6 +7668,7 @@ cp_parser_lambda_declarator_opt (cp_parser* parser, tree lambda_expr)
quals = (LAMBDA_EXPR_MUTABLE_P (lambda_expr)
? TYPE_UNQUALIFIED : TYPE_QUAL_CONST);
declarator = make_call_declarator (declarator, param_list, quals,
+ VIRT_SPEC_UNSPECIFIED,
exception_spec,
/*late_return_type=*/NULL_TREE);
declarator->id_loc = LAMBDA_EXPR_LOCATION (lambda_expr);
@@ -14887,6 +14892,7 @@ cp_parser_direct_declarator (cp_parser* parser,
if (member_p || cp_parser_parse_definitely (parser))
{
cp_cv_quals cv_quals;
+ cp_virt_specifiers virt_specifiers;
tree exception_specification;
tree late_return;
@@ -14903,6 +14909,8 @@ cp_parser_direct_declarator (cp_parser* parser,
/* And the exception-specification. */
exception_specification
= cp_parser_exception_specification_opt (parser);
+ /* Parse the virt-specifier-seq. */
+ virt_specifiers = cp_parser_virt_specifier_seq_opt (parser);
late_return
= cp_parser_late_return_type_opt (parser);
@@ -14911,6 +14919,7 @@ cp_parser_direct_declarator (cp_parser* parser,
declarator = make_call_declarator (declarator,
params,
cv_quals,
+ virt_specifiers,
exception_specification,
late_return);
/* Any subsequent parameter lists are to do with
@@ -15418,6 +15427,56 @@ cp_parser_cv_qualifier_seq_opt (cp_parser* parser)
return cv_quals;
}
+/* Parse an (optional) virt-specifier-seq.
+
+ virt-specifier-seq:
+ virt-specifier virt-specifier-seq [opt]
+
+ virt-specifier:
+ override
+ final
+
+ Returns a bitmask representing the virt-specifiers. */
+
+static cp_virt_specifiers cp_parser_virt_specifier_seq_opt
+ (cp_parser* parser)
+{
+ cp_virt_specifiers virt_specifiers = VIRT_SPEC_UNSPECIFIED;
+
+ while (true)
+ {
+ cp_token *token;
+ cp_virt_specifiers virt_specifier;
+
+ /* Peek at the next token. */
+ token = cp_lexer_peek_token (parser->lexer);
+ /* See if it's a virt-specifier-qualifier. */
+ if (token->type != CPP_NAME)
+ break;
+ if (!strcmp (IDENTIFIER_POINTER(token->u.value), "override"))
+ virt_specifier = VIRT_SPEC_OVERRIDE;
+ else if (!strcmp (IDENTIFIER_POINTER(token->u.value), "final"))
+ virt_specifier = VIRT_SPEC_FINAL;
+ else
+ virt_specifier = VIRT_SPEC_UNSPECIFIED;
+
+ if (!virt_specifier)
+ break;
+
+ if (virt_specifiers & virt_specifier)
+ {
+ error_at (token->location, "duplicate virt-specifier");
+ cp_lexer_purge_token (parser->lexer);
+ }
+ else
+ {
+ cp_lexer_consume_token (parser->lexer);
+ virt_specifiers |= virt_specifier;
+ }
+ }
+ return virt_specifiers;
+}
+
/* Parse a late-specified return type, if any. This is not a separate
non-terminal, but part of a function declarator, which looks like
diff --git a/gcc/cp/search.c b/gcc/cp/search.c
index e7d2048..cf0b1a0 100644
--- a/gcc/cp/search.c
+++ b/gcc/cp/search.c
@@ -1920,6 +1920,12 @@ check_final_overrider (tree overrider, tree basefn)
}
return 0;
}
+ if (DECL_FINAL_P (basefn))
+ {
+ error ("virtual function %q+D", overrider);
+ error ("overriding final function %q+D", basefn);
+ return 0;
+ }
return 1;
}
diff --git a/gcc/testsuite/g++.dg/inherit/virtual9.C b/gcc/testsuite/g++.dg/inherit/virtual9.C
new file mode 100644
index 0000000..139a0bc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/inherit/virtual9.C
@@ -0,0 +1,39 @@
+// { dg-do compile }
+struct B
+{
+ virtual void f() final {}
+ virtual void g() {}
+};
+
+struct B2
+{
+ virtual void h() {}
+};
+
+struct D : B
+{
+ virtual void g() override final {} // { dg-error "overriding" }
+};
+
+template <class T> struct D2 : T
+{
+ void h() override {} // { dg-error "marked override, but does not override" }
+};
+
+struct D3 : D
+{
+ void g() {} // { dg-error "virtual function" }
+};
+
+struct B3
+{
+ virtual void f() final final {} // { dg-error "duplicate virt-specifier" }
+};
+
+void g() override {} // { dg-error "virt-specifiers" }
+
+int main()
+{
+ D2<B> d2;
+ D2<B2> d3;
+}
diff --git a/gcc/tree.h b/gcc/tree.h
index 8baaf7b..72e50fc 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -2253,11 +2253,24 @@ extern enum machine_mode vector_type_mode (const_tree);
/* There is a TYPE_QUAL value for each type qualifier. They can be
combined by bitwise-or to form the complete set of qualifiers for a
type. */
-
-#define TYPE_UNQUALIFIED 0x0
-#define TYPE_QUAL_CONST 0x1
-#define TYPE_QUAL_VOLATILE 0x2
-#define TYPE_QUAL_RESTRICT 0x4
+enum cv_qualifier
+ {
+ TYPE_UNQUALIFIED = 0x0,
+ TYPE_QUAL_CONST = 0x1,
+ TYPE_QUAL_VOLATILE = 0x2,
+ TYPE_QUAL_RESTRICT = 0x4
+ };
+
+/* Non-static member functions have an optional virt-specifier-seq.
+ There is a VIRT_SPEC value for each virt-specifier.
+ They can be combined by bitwise-or to form the complete set of
+ virt-specifiers for a member function. */
+enum virt_specifier
+ {
+ VIRT_SPEC_UNSPECIFIED = 0x0,
+ VIRT_SPEC_FINAL = 0x1,
+ VIRT_SPEC_OVERRIDE = 0x2
+ };
/* Encode/decode the named memory support as part of the qualifier. If more
than 8 qualifiers are added, these macros need to be adjusted. */
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