On 12/16/19 3:51 PM, Jason Merrill wrote:
On 12/9/19 7:29 PM, Martin Sebor wrote:
Just a few nits:
+/* A mapping between a TYPE_DECL for a class and the class_decl_loc_t
+ description above. */
+typedef hash_map<tree_decl_hash, class_decl_loc_t> class_to_loc_map_t;
+static class_to_loc_map_t class2loc;
I think we can make these members of class_decl_loc_t, now that we
aren't marking them with GTY.
+ class_decl_loc_t *rdl = class2loc.get (type_decl);
+ if (!rdl)
+ {
+ tree type = TREE_TYPE (type_decl);
+ if (def_p || !COMPLETE_TYPE_P (type))
+ {
+ /* TYPE_DECL is the first declaration or definition of the type
+ (outside precompiled headers -- see below). Just create
+ a new entry for it. */
+ class2loc.put (type_decl, class_decl_loc_t (class_key, false,
def_p));
+ return;
+ }
+
+ /* TYPE was previously defined in some unknown precompiled
hdeader.
+ Simply add a record of its definition at an unknown location and
+ proceed below to add a reference to it at the current location.
+ (Declarations in precompiled headers that are not definitions
+ are ignored.) */
+ tag_types def_key
+ = CLASSTYPE_DECLARED_CLASS (type) ? class_type : record_type;
+ location_t def_loc = DECL_SOURCE_LOCATION (type_decl);
+ rdl = &class2loc.get_or_insert (type_decl);
+ *rdl = class_decl_loc_t (def_key, false, true, def_loc);
+ }
It seems that you could use get_or_insert at the top, since you always
end up creating an element if there wasn't one already.
+ /* A prior declaration of TYPE_DECL has been seen. */
+
+ if (rdl->idxdef != UINT_MAX && rdl->def_class_key == class_key)
+ /* Do nothing if the class-key in this declaration matches
+ the definition. */
+ return;
...
I still think that the rest of this function could be a non-static
member function to avoid so many "rdl->".
Attached is another revision with these changes.
Martin
PR c++/61339 - add warning for mismatch between struct and class
gcc/c-family/ChangeLog:
PR c++/61339
* c.opt (-Wmismatched-tags, -Wredundant-tags): New options.
gcc/cp/ChangeLog:
PR c++/61339
* parser.c (cp_parser_maybe_warn_enum_key): New function.
(class_decl_loc_t): New class.
(cp_parser_elaborated_type_specifier): Call
cp_parser_maybe_warn_enum_key.
(cp_parser_class_head): Call cp_parser_check_class_key.
(cp_parser_check_class_key): Add arguments. Call class_decl_loc_t::add.
(c_parse_file): Call class_decl_loc_t::diag_mismatched_tags.
gcc/testsuite/ChangeLog:
PR c++/61339
* g++.dg/warn/Wmismatched-tags.C: New test.
* g++.dg/warn/Wredundant-tags.C: New test.
* g++.dg/pch/Wmismatched-tags.C: New test.
* g++.dg/pch/Wmismatched-tags.Hs: New test header.
gcc/ChangeLog:
PR c++/61339
* doc/invoke.texi (-Wmismatched-tags, -Wredundant-tags): Document
new C++ options.
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 914a2f0ef44..4f3d3cf0d43 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -755,6 +755,10 @@ Wmisleading-indentation
C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
Warn when the indentation of the code does not reflect the block structure.
+Wmismatched-tags
+C++ Objc++ Var(warn_mismatched_tags) Warning
+Warn when a class is redeclared or referenced using a mismatched class-key.
+
Wmissing-braces
C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
Warn about possibly missing braces around initializers.
@@ -783,6 +787,10 @@ Wpacked-not-aligned
C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
Warn when fields in a struct with the packed attribute are misaligned.
+Wredundant-tags
+C++ Objc++ Var(warn_redundant_tags) Warning
+Warn when a class or enumerated type is referenced using a redundant class-key.
+
Wsized-deallocation
C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
Warn about missing sized deallocation functions.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 16d1359c47d..d02a4afd736 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -2599,8 +2599,9 @@ static enum tag_types cp_parser_token_is_class_key
(cp_token *);
static enum tag_types cp_parser_token_is_type_parameter_key
(cp_token *);
+static void cp_parser_maybe_warn_enum_key (cp_parser *, location_t, tree, rid);
static void cp_parser_check_class_key
- (enum tag_types, tree type);
+(cp_parser *, location_t, enum tag_types, tree type, bool, bool);
static void cp_parser_check_access_in_redeclaration
(tree type, location_t location);
static bool cp_parser_optional_template_keyword
@@ -18498,6 +18499,11 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
tree globalscope;
cp_token *token = NULL;
+ /* For class and enum types the location of the class-key or enum-key. */
+ location_t key_loc = cp_lexer_peek_token (parser->lexer)->location;
+ /* For a scoped enum, the 'class' or 'struct' keyword id. */
+ rid scoped_key = RID_MAX;
+
/* See if we're looking at the `enum' keyword. */
if (cp_lexer_next_token_is_keyword (parser->lexer, RID_ENUM))
{
@@ -18508,10 +18514,11 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
/* Issue a warning if the `struct' or `class' key (for C++0x scoped
enums) is used here. */
cp_token *token = cp_lexer_peek_token (parser->lexer);
- if (cp_parser_is_keyword (token, RID_CLASS)
- || cp_parser_is_keyword (token, RID_STRUCT))
+ if (cp_parser_is_keyword (token, scoped_key = RID_CLASS)
+ || cp_parser_is_keyword (token, scoped_key = RID_STRUCT))
{
- gcc_rich_location richloc (token->location);
+ location_t loc = token->location;
+ gcc_rich_location richloc (loc);
richloc.add_range (input_location);
richloc.add_fixit_remove ();
pedwarn (&richloc, 0, "elaborated-type-specifier for "
@@ -18519,7 +18526,12 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
token->u.value);
/* Consume the `struct' or `class' and parse it anyway. */
cp_lexer_consume_token (parser->lexer);
+ /* Create a combined location for the whole scoped-enum-key. */
+ key_loc = make_location (key_loc, key_loc, loc);
}
+ else
+ scoped_key = RID_MAX;
+
/* Parse the attributes. */
attributes = cp_parser_attributes_opt (parser);
}
@@ -18535,6 +18547,7 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
/* Otherwise it must be a class-key. */
else
{
+ key_loc = cp_lexer_peek_token (parser->lexer)->location;
tag_type = cp_parser_class_key (parser);
if (tag_type == none_type)
return error_mark_node;
@@ -18845,13 +18858,18 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
"attributes ignored on elaborated-type-specifier that is not a forward declaration");
}
- if (tag_type != enum_type)
+ if (tag_type == enum_type)
+ cp_parser_maybe_warn_enum_key (parser, key_loc, type, scoped_key);
+ else
{
+ /* Diagnose class/struct/union mismatches. */
+ cp_parser_check_class_key (parser, key_loc, tag_type, type, false,
+ cp_parser_declares_only_class_p (parser));
+
/* Indicate whether this class was declared as a `class' or as a
`struct'. */
- if (CLASS_TYPE_P (type))
+ if (CLASS_TYPE_P (type) && !currently_open_class (type))
CLASSTYPE_DECLARED_CLASS (type) = (tag_type == class_type);
- cp_parser_check_class_key (tag_type, type);
}
/* A "<" cannot follow an elaborated type specifier. If that
@@ -24389,11 +24407,14 @@ cp_parser_class_head (cp_parser* parser,
parser->num_template_parameter_lists);
}
+ /* Diagnose class/struct/union mismatches. */
+ cp_parser_check_class_key (parser, UNKNOWN_LOCATION, class_key, type,
+ true, true);
+
/* Indicate whether this class was declared as a `class' or as a
`struct'. */
if (TREE_CODE (type) == RECORD_TYPE)
- CLASSTYPE_DECLARED_CLASS (type) = (class_key == class_type);
- cp_parser_check_class_key (class_key, type);
+ CLASSTYPE_DECLARED_CLASS (type) = class_key == class_type;
/* If this type was already complete, and we see another definition,
that's an error. Likewise if the type is already being defined:
@@ -30617,14 +30638,169 @@ cp_parser_token_is_type_parameter_key (cp_token* token)
}
}
-/* Issue an error message if the CLASS_KEY does not match the TYPE. */
+/* Diagnose redundant enum-keys. */
+
+static void
+cp_parser_maybe_warn_enum_key (cp_parser *parser, location_t key_loc,
+ tree type, rid scoped_key)
+{
+ tree type_decl = TYPE_MAIN_DECL (type);
+ tree name = DECL_NAME (type_decl);
+ /* Look up the NAME to see if it unambiguously refers to the TYPE
+ and set KEY_REDUNDANT if so. */
+ tree decl = cp_parser_lookup_name_simple (parser, name, input_location);
+
+ /* The enum-key is redundant for uses of the TYPE that are not
+ declarations and for which name lookup returns just the type
+ itself. */
+ if (decl == type_decl)
+ {
+ gcc_rich_location richloc (key_loc);
+ richloc.add_fixit_remove (key_loc);
+ warning_at (&richloc, OPT_Wredundant_tags,
+ "redundant enum-key %<enum%s%> in reference to %q#T",
+ (scoped_key == RID_CLASS ? " class"
+ : scoped_key == RID_STRUCT ? " struct" : ""), type);
+ }
+}
+
+/* Describes the set of declarations of a struct, class, or class template
+ or its specializations. Used for -Wmismatched-tags. */
+
+class class_decl_loc_t
+{
+ public:
+
+ class_decl_loc_t ()
+ : locvec (), idxdef (), def_class_key ()
+ {
+ locvec.create (4);
+ }
+
+ /* Constructs an object for a single declaration of a class with
+ CLASS_KEY at the current location in the current function (or
+ at another scope). KEY_REDUNDANT is true if the class-key may
+ be omitted in the current context without an ambiguity with
+ another symbol with the same name.
+ DEF_P is true for a class declaration that is a definition.
+ CURLOC is the associated location. */
+ class_decl_loc_t (tag_types class_key, bool key_redundant, bool def_p,
+ location_t curloc = input_location)
+ : locvec (), idxdef (def_p ? 0 : UINT_MAX), def_class_key (class_key)
+ {
+ locvec.create (4);
+ class_key_loc_t ckl (current_function_decl, curloc, class_key,
+ key_redundant);
+ locvec.quick_push (ckl);
+ }
+
+ /* Copy, assign, and destroy the object. Necessary because LOCVEC
+ isn't safely copyable and assignable and doesn't release storage
+ on its own. */
+ class_decl_loc_t (const class_decl_loc_t &rhs)
+ : locvec (rhs.locvec.copy ()), idxdef (rhs.idxdef),
+ def_class_key (rhs.def_class_key)
+ { }
+
+ class_decl_loc_t& operator= (const class_decl_loc_t &rhs)
+ {
+ if (this == &rhs)
+ return *this;
+ locvec.release ();
+ locvec = rhs.locvec.copy ();
+ idxdef = rhs.idxdef;
+ def_class_key = rhs.def_class_key;
+ return *this;
+ }
+
+ ~class_decl_loc_t ()
+ {
+ locvec.release ();
+ }
+
+ /* Issues -Wmismatched-tags for a single class. */
+ void diag_mismatched_tags (tree);
+
+ /* Issues -Wmismatched-tags for all classes. */
+ static void diag_mismatched_tags ();
+
+ /* Adds TYPE_DECL to the collection of class decls. */
+ static void add (tree, tag_types, bool, bool);
+
+ /* Either adds this decl to the collection of class decls
+ or diagnoses it, whichever is appropriate. */
+ void add_or_diag_mismatched_tag (tree, tag_types, bool, bool);
+
+private:
+
+ tree function (unsigned i) const
+ {
+ return locvec[i].func;
+ }
+
+ location_t location (unsigned i) const
+ {
+ return locvec[i].loc;
+ }
+
+ bool key_redundant (unsigned i) const
+ {
+ return locvec[i].key_redundant;
+ }
+
+ tag_types class_key (unsigned i) const
+ {
+ return locvec[i].class_key;
+ }
+
+ /* The location of a single mention of a class type with the given
+ class-key. */
+ struct class_key_loc_t
+ {
+ class_key_loc_t (tree func, location_t loc, tag_types key, bool redundant)
+ : func (func), loc (loc), class_key (key), key_redundant (redundant) { }
+
+ /* The function the type is mentioned in. */
+ tree func;
+ /* The exact location. */
+ location_t loc;
+ /* The class-key used in the mention of the type. */
+ tag_types class_key;
+ /* True when the class-key could be omitted at this location
+ without an ambiguity with another symbol of the same name. */
+ bool key_redundant;
+ };
+ /* Avoid using auto_vec here since it's not safe to copy due to pr90904. */
+ vec <class_key_loc_t> locvec;
+ /* LOCVEC index of the definition or UINT_MAX if none exists. */
+ unsigned idxdef;
+ /* The class-key the class was last declared with or none_type when
+ it has been declared with a mismatched key. */
+ tag_types def_class_key;
+
+ /* A mapping between a TYPE_DECL for a class and the class_decl_loc_t
+ description above. */
+ typedef hash_map<tree_decl_hash, class_decl_loc_t> class_to_loc_map_t;
+ static class_to_loc_map_t class2loc;
+};
+
+class_decl_loc_t::class_to_loc_map_t class_decl_loc_t::class2loc;
+
+/* Issue an error message if the CLASS_KEY does not match the TYPE.
+ DEF_P is expected to be set for a definition of class TYPE. DECL_P
+ is set for a declaration of class TYPE and clear for a reference to
+ it that is not a declaration of it. */
static void
-cp_parser_check_class_key (enum tag_types class_key, tree type)
+cp_parser_check_class_key (cp_parser *parser, location_t key_loc,
+ tag_types class_key, tree type, bool def_p,
+ bool decl_p)
{
if (type == error_mark_node)
return;
- if ((TREE_CODE (type) == UNION_TYPE) != (class_key == union_type))
+
+ bool seen_as_union = TREE_CODE (type) == UNION_TYPE;
+ if (seen_as_union != (class_key == union_type))
{
if (permerror (input_location, "%qs tag used in naming %q#T",
class_key == union_type ? "union"
@@ -30632,7 +30808,241 @@ cp_parser_check_class_key (enum tag_types class_key, tree type)
type))
inform (DECL_SOURCE_LOCATION (TYPE_NAME (type)),
"%q#T was previously declared here", type);
+ return;
}
+
+ if (!warn_mismatched_tags && !warn_redundant_tags)
+ return;
+
+ tree type_decl = TYPE_MAIN_DECL (type);
+ tree name = DECL_NAME (type_decl);
+ /* Look up the NAME to see if it unambiguously refers to the TYPE
+ and set KEY_REDUNDANT if so. */
+ tree decl = cp_parser_lookup_name_simple (parser, name, input_location);
+
+ /* The class-key is redundant for uses of the CLASS_TYPE that are
+ neither definitions of it nor declarations, and for which name
+ lookup returns just the type itself. */
+ bool key_redundant = !def_p && !decl_p && decl == type_decl;
+ if (key_redundant)
+ {
+ gcc_rich_location richloc (key_loc);
+ richloc.add_fixit_remove (key_loc);
+ warning_at (&richloc, OPT_Wredundant_tags,
+ "redundant class-key %qs in reference to %q#T",
+ class_key == union_type ? "union"
+ : class_key == record_type ? "struct" : "class",
+ type);
+ }
+
+ if (seen_as_union || !warn_mismatched_tags)
+ return;
+
+ class_decl_loc_t::add (type_decl, class_key, key_redundant, def_p);
+}
+
+/* Adds TYPE_DECL to the collection of class decls. */
+
+void
+class_decl_loc_t::add (tree type_decl, tag_types class_key, bool redundant,
+ bool def_p)
+{
+ class_decl_loc_t *rdl = class2loc.get (type_decl);
+ if (!rdl)
+ {
+ rdl = &class2loc.get_or_insert (type_decl);
+
+ tree type = TREE_TYPE (type_decl);
+ if (def_p || !COMPLETE_TYPE_P (type))
+ {
+ /* TYPE_DECL is the first declaration or definition of the type
+ (outside precompiled headers -- see below). Just create
+ a new entry for it. */
+ *rdl = class_decl_loc_t (class_key, false, def_p);
+ return;
+ }
+
+ /* TYPE was previously defined in some unknown precompiled hdeader.
+ Simply add a record of its definition at an unknown location and
+ proceed below to add a reference to it at the current location.
+ (Declarations in precompiled headers that are not definitions
+ are ignored.) */
+ tag_types def_key
+ = CLASSTYPE_DECLARED_CLASS (type) ? class_type : record_type;
+ location_t def_loc = DECL_SOURCE_LOCATION (type_decl);
+ *rdl = class_decl_loc_t (def_key, false, true, def_loc);
+ }
+
+ /* A prior declaration of TYPE_DECL has been seen. */
+
+ if (rdl->idxdef != UINT_MAX && rdl->def_class_key == class_key)
+ /* Do nothing if the class-key in this declaration matches
+ the definition. */
+ return;
+
+ rdl->add_or_diag_mismatched_tag (type_decl, class_key, redundant, def_p);
+}
+
+/* Either adds this DECL corresponding to the TYPE_DECL to the collection
+ of class decls or diagnoses it, whichever is appropriate. */
+
+void
+class_decl_loc_t::add_or_diag_mismatched_tag (tree type_decl,
+ tag_types class_key,
+ bool redundant,
+ bool def_p)
+{
+ /* Reset the CLASS_KEY associated with this type on mismatch.
+ This is an optimization that lets the diagnostic code skip
+ over classes that use the same class-key in all declarations. */
+ if (def_class_key != class_key)
+ def_class_key = none_type;
+
+ /* Set IDXDEF to the index of the vector corresponding to
+ the definition. */
+ if (def_p)
+ idxdef = locvec.length ();
+
+ /* Append a record of this declaration to the vector. */
+ class_key_loc_t ckl (current_function_decl, input_location, class_key,
+ redundant);
+ locvec.safe_push (ckl);
+
+ if (idxdef == UINT_MAX)
+ return;
+
+ /* As a space optimization diagnose declarations of a class
+ whose definition has been seen and purge the LOCVEC of
+ all entries except the definition. */
+ diag_mismatched_tags (type_decl);
+ if (idxdef)
+ {
+ class_decl_loc_t::class_key_loc_t ent = locvec[idxdef];
+ locvec.release ();
+ locvec.reserve (2);
+ locvec.safe_push (ent);
+ idxdef = 0;
+ }
+ else
+ /* Pop the entry pushed above for this declaration. */
+ locvec.pop ();
+}
+
+/* Issues -Wmismatched-tags for a single class. */
+
+void
+class_decl_loc_t::diag_mismatched_tags (tree type_decl)
+{
+ unsigned ndecls = locvec.length ();
+
+ /* Skip a declaration that consistently uses the same class-key
+ or one with just a solitary declaration (i.e., TYPE_DECL). */
+ if (def_class_key != none_type || ndecls < 2)
+ return;
+
+ /* Save the current function before changing it below. */
+ tree save_func = current_function_decl;
+ /* Set if a class definition for RECLOC has been seen. */
+ bool def_p = idxdef < ndecls;
+ unsigned idxguide = def_p ? idxdef : 0;
+ unsigned idx = 0;
+ /* Advance IDX to the first declaration that either is not
+ a definition or that doesn't match the first declaration
+ if no definition is provided. */
+ while (class_key (idx) == class_key (idxguide))
+ if (++idx == ndecls)
+ return;
+
+ /* The class-key the class is expected to be declared with: it's
+ either the key used in its definition or the first declaration
+ if no definition has been provided. */
+ tag_types xpect_key = class_key (def_p ? idxguide : 0);
+ const char *xmatchkstr = xpect_key == record_type ? "class" : "struct";
+ const char *xpectkstr = xpect_key == record_type ? "struct" : "class";
+ /* Set the function declaration to print in diagnostic context. */
+ current_function_decl = function (idx);
+
+ location_t loc = location (idx);
+ bool key_redundant_p = key_redundant (idx);
+ auto_diagnostic_group d;
+ /* Issue a warning for the first mismatched declaration.
+ Avoid using "%#qT" since the class-key for the same type will
+ be the same regardless of which one was used in the declaraion. */
+ warning_at (loc, OPT_Wmismatched_tags,
+ "%qT declared with a mismatched class-key %qs",
+ type_decl, xmatchkstr);
+
+ /* Suggest how to avoid the warning for each instance since
+ the guidance may be different depending on context. */
+ inform (loc,
+ (key_redundant_p
+ ? G_("remove the class-key or replace it with %qs")
+ : G_("replace the class-key with %qs")),
+ xpectkstr);
+
+ /* Also point to the first declaration or definition that guided
+ the decision to issue the warning above. */
+ inform (location (idxguide),
+ (def_p
+ ? G_("%qT defined as %qs here")
+ : G_("%qT first declared as %qs here")),
+ type_decl, xpectkstr);
+
+ /* Issue warnings for the remaining inconsistent declarations. */
+ for (unsigned i = idx + 1; i != ndecls; ++i)
+ {
+ tag_types clskey = class_key (i);
+ /* Skip over the declarations that match either the definition
+ if one was provided or the first declaration. */
+ if (clskey == xpect_key)
+ continue;
+
+ loc = location (i);
+ key_redundant_p = key_redundant (i);
+ /* Set the function declaration to print in diagnostic context. */
+ current_function_decl = function (i);
+ warning_at (loc, OPT_Wmismatched_tags,
+ "%qT declared with a mismatched class-key %qs",
+ type_decl, xmatchkstr);
+ /* Suggest how to avoid the warning for each instance since
+ the guidance may be different depending on context. */
+ inform (loc,
+ (key_redundant_p
+ ? G_("remove the class-key or replace it with %qs")
+ : G_("replace the class-key with %qs")),
+ xpectkstr);
+ }
+
+ /* Restore the current function in case it was replaced above. */
+ current_function_decl = save_func;
+}
+
+/* Issues -Wmismatched-tags for all classes. Called at the end
+ of processing a translation unit, after declarations of all class
+ types and their uses have been recorded. */
+
+void
+class_decl_loc_t::diag_mismatched_tags ()
+{
+ /* CLASS2LOC should be empty if -Wmismatched-tags is disabled. */
+ gcc_assert (warn_mismatched_tags || class2loc.is_empty ());
+
+ /* Save the current function before changing it below. It should
+ be null at this point. */
+ tree save_func = current_function_decl;
+
+ /* Iterate over the collected class/struct declarations. */
+ typedef class_to_loc_map_t::iterator iter_t;
+ for (iter_t it = class2loc.begin (); it != class2loc.end (); ++it)
+ {
+ tree type_decl = (*it).first;
+ class_decl_loc_t &recloc = (*it).second;
+ recloc.diag_mismatched_tags (type_decl);
+ }
+
+ class2loc.empty ();
+ /* Restore the current function. */
+ current_function_decl = save_func;
}
/* Issue an error message if DECL is redeclared with different
@@ -43065,6 +43475,8 @@ c_parse_file (void)
push_deferring_access_checks (flag_access_control
? dk_no_deferred : dk_no_check);
cp_parser_translation_unit (the_parser);
+ class_decl_loc_t::diag_mismatched_tags ();
+
the_parser = NULL;
finish_translation_unit ();
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index f04e9151196..216839537de 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -236,7 +236,7 @@ in the following sections.
-Wliteral-suffix @gol
-Wmultiple-inheritance -Wno-init-list-lifetime @gol
-Wnamespaces -Wnarrowing @gol
--Wpessimizing-move -Wredundant-move @gol
+-Wpessimizing-move -Wredundant-move -Wredundant-tags @gol
-Wnoexcept -Wnoexcept-type -Wclass-memaccess @gol
-Wnon-virtual-dtor -Wreorder -Wregister @gol
-Weffc++ -Wstrict-null-sentinel -Wtemplates @gol
@@ -3323,6 +3323,21 @@ treats the return value as if it were designated by an rvalue.
This warning is enabled by @option{-Wextra}.
+@item -Wredundant-tags @r{(C++ and Objective-C++ only)}
+@opindex Wredundant-tags
+@opindex Wno-redundant-tags
+Warn about redundant class-key and enum-key in references to class types
+and enumerated types in contexts where the key can be eliminated without
+causing an ambiguity. For example
+
+@smallexample
+struct foo;
+struct foo *p; // -Wredundant-tags, keyword struct can be eliminated
+
+void foo (); // "hides" struct foo
+void bar (struct foo&); // no warning, keyword struct cannot be eliminated
+@end smallexample
+
@item -fext-numeric-literals @r{(C++ and Objective-C++ only)}
@opindex fext-numeric-literals
@opindex fno-ext-numeric-literals
@@ -3458,6 +3473,32 @@ The warning is inactive inside a system header file, such as the STL, so
one can still use the STL. One may also instantiate or specialize
templates.
+@item -Wmismatched-tags @r{(C++ and Objective-C++ only)}
+@opindex Wmismatched-tags
+@opindex Wno-mismatched-tags
+Warn for declarations of structs, classes, and class templates and their
+specializations with a class-key that does not match either the definition
+or the first declaration if no definition is provided.
+
+For example, the declaration of @code{struct Object} in the argument list
+of @code{draw} triggers the warning. To avoid it, either remove the redundant
+class-key @code{struct} or replace it with @code{class} to match its definition.
+@smallexample
+class Object @{
+public:
+ virtual ~Object () = 0;
+@};
+void draw (struct Object*);
+@end smallexample
+
+It is not wrong to declare a class with the class-key @code{struct} as
+the example above shows. The @option{-Wmismatched-tags} option is intended
+to help achieve a consistent style of class declarations. In code that is
+intended to be portable to Windows-based compilers the warning helps prevent
+unresolved references due to the difference in the mangling of symbols
+declared with different class-keys. The option can be used either on its
+own or in conjunction with @option{-Wredundant-tags}.
+
@item -Wmultiple-inheritance @r{(C++ and Objective-C++ only)}
@opindex Wmultiple-inheritance
@opindex Wno-multiple-inheritance
diff --git a/gcc/testsuite/g++.dg/pch/Wmismatched-tags.C b/gcc/testsuite/g++.dg/pch/Wmismatched-tags.C
new file mode 100644
index 00000000000..89b6ba55688
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pch/Wmismatched-tags.C
@@ -0,0 +1,15 @@
+/* PR c++/61339 - add mismatch between struct and class
+ Verify that declarations that don't match definitions in precompiled
+ headers are diagnosed.
+ { dg-options "-Wall -Wmismatched-tags" } */
+
+#include "Wmismatched-tags.H"
+
+class PCHDeclaredClass;
+struct PCHDeclaredStruct;
+
+struct PCHDefinedClass; // { dg-warning "declared with a mismatched class-key 'struct'" }
+class PCHDefinedStruct; // { dg-warning "declared with a mismatched class-key 'class'" }
+
+class PCHDeclaredClass { };
+struct PCHDeclaredStruct { };
diff --git a/gcc/testsuite/g++.dg/pch/Wmismatched-tags.Hs b/gcc/testsuite/g++.dg/pch/Wmismatched-tags.Hs
new file mode 100644
index 00000000000..f4c5dc557e9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pch/Wmismatched-tags.Hs
@@ -0,0 +1,7 @@
+class PCHDeclaredClass;
+
+struct PCHDeclaredStruct;
+
+class PCHDefinedClass { };
+
+struct PCHDefinedStruct { };
\ No newline at end of file
diff --git a/gcc/testsuite/g++.dg/warn/Wmismatched-tags.C b/gcc/testsuite/g++.dg/warn/Wmismatched-tags.C
new file mode 100644
index 00000000000..36a7903234a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wmismatched-tags.C
@@ -0,0 +1,278 @@
+/* PR c++/61339 - add mismatch between struct and class
+ Test to verify that -Wmismatched-tags is issued for declarations
+ of the same class using different class-ids.
+ { dg-do compile }
+ { dg-options "-Wmismatched-tags" } */
+
+namespace Classes
+{
+class A;
+class A;
+
+struct B;
+struct B;
+
+union C;
+union C;
+
+struct D; // { dg-warning "Classes::D' declared with a mismatched class-key 'struct'" }
+class D { }; // { dg-message "Classes::D' defined as 'class' here" }
+
+class E; // { dg-warning "Classes::E' declared with a mismatched class-key 'class'" }
+struct E { }; // { dg-message "Classes::E' defined as 'struct' here" }
+
+class D;
+struct E;
+
+class D;
+struct E;
+
+struct D; // { dg-warning "Classes::D' declared with a mismatched class-key" }
+
+class E; // { dg-warning "Classes::E' declared with a mismatched class-key" }
+
+class F; // { dg-message "Classes::F' first declared as 'class' here" }
+class F;
+
+struct G { }; // { dg-message "Classes::G' defined as 'struct' here" }
+} // namespace Classes
+
+
+namespace Classes
+{
+class A;
+struct B;
+union C;
+class D;
+struct E;
+
+struct F; // { dg-warning "Classes::F' declared with a mismatched class-key" }
+
+struct G;
+}
+
+// Verify that the correct hint is provided, one to remove the class-key
+// when it's redundant, and one to (only) replace it with the correct one
+// when it's needed to disambiguate the reference to the class type.
+namespace RemoveOrReplace
+{
+struct Func;
+class Func; // { dg-warning "RemoveOrReplace::Func' declared with a mismatched class-key 'class'" }
+ // { dg-message "replace the class-key with 'struct'" "hint to remove" { target *-*-* } .-1 }
+
+void Func ();
+
+class Func; // { dg-warning "RemoveOrReplace::Func' declared with a mismatched class-key 'class'" }
+ // { dg-message "replace the class-key with 'struct'" "hint to replace" { target *-*-* } .-1 }
+
+class Var;
+struct Var; // { dg-warning "RemoveOrReplace::Var' declared with a mismatched class-key 'struct'" }
+ // { dg-message "replace the class-key with 'class'" "hint to remove" { target *-*-* } .-1 }
+void f (struct Var*); // { dg-warning "RemoveOrReplace::Var' declared with a mismatched class-key 'struct'" }
+ // { dg-message "remove the class-key or replace it with 'class'" "hint to remove" { target *-*-* } .-1 }
+
+int Var;
+
+struct Var; // { dg-warning "RemoveOrReplace::Var' declared with a mismatched class-key 'struct'" }
+ // { dg-message "replace the class-key with 'class'" "hint to replace" { target *-*-* } .-1 }
+}
+
+namespace GlobalObjects
+{
+class A; // { dg-message "'GlobalObjects::A' first declared as 'class' here" }
+struct B; // { dg-message "'GlobalObjects::B' first declared as 'struct' here" }
+class C { }; // { dg-message "'GlobalObjects::C' defined as 'class' here" }
+
+extern A a0;
+extern class A a1;
+extern class A a2;
+
+extern B b0;
+extern struct B b1;
+extern struct B b2;
+
+extern struct A a3; // { dg-warning "GlobalObjects::A' declared with a mismatched class-key" }
+extern class A a4;
+
+extern class B b3; // { dg-warning "GlobalObjects::B' declared with a mismatched class-key" }
+extern struct B b4;
+
+extern struct C c[]; // { dg-warning "GlobalObjects::C' declared with a mismatched class-key" }
+ // { dg-message "remove the class-key or replace it with 'class'" "hint to remove" { target *-*-* } .-1 }
+
+extern char
+arr[sizeof (struct C)]; // { dg-warning "GlobalObjects::C' declared with a mismatched class-key" }
+ // { dg-message "remove the class-key or replace it with 'class'" "hint to remove" { target *-*-* } .-1 }
+} // namespace GlobalObjects
+
+
+namespace LocalObjects
+{
+class A; // { dg-message "LocalObjects::A' first declared as 'class' here" }
+struct B; // { dg-message "LocalObjects::B' first declared as 'struct' here" }
+
+void f (A*, B&)
+{
+ class A *a1;
+ class A *a2;
+
+ struct B *b1;
+ struct B *b2;
+
+ struct A *a3; // { dg-warning "LocalObjects::A' declared with a mismatched class-key" }
+ class A *a4;
+
+ class B *b3; // { dg-warning "LocalObjects::B' declared with a mismatched class-key" }
+ struct B *b4;
+}
+
+void g (struct A*); // { dg-warning "LocalObjects::A' declared with a mismatched class-key" }
+
+} // namespace LocalObjects
+
+
+namespace MemberClasses
+{
+struct A { struct B; };
+struct C { struct D; struct D; struct D { }; };
+struct E { class F; class F { }; class F; };
+
+struct G {
+ struct H; // { dg-message "MemberClasses::G::H' first declared as 'struct' here" }
+ class H; // { dg-warning "MemberClasses::G::H' declared with a mismatched class-key" }
+ class I { }; // { dg-message "MemberClasses::G::I' defined as 'class' here" }
+ struct I; // { dg-warning "MemberClasses::G::I' declared with a mismatched class-key" }
+};
+} // namespace MemberClasses
+
+
+namespace DataMembers
+{
+struct A { struct B *p; };
+struct C { struct D *p; struct D *q; struct D { } d; };
+struct E { class F &r; class F { } f; class F *p; };
+
+class G; // { dg-message "DataMembers::G' first declared as 'class' here" }
+struct H; // { dg-message "DataMembers::H' first declared as 'struct' here" }
+
+struct I {
+ struct G *p0; // { dg-warning "DataMembers::G' declared with a mismatched class-key" }
+ class G *p1;
+
+ struct H &r0;
+ class H &r1; // { dg-warning "DataMembers::H' declared with a mismatched class-key" }
+
+ class J { }; // { dg-message "DataMembers::I::J' defined as 'class' here" }
+ struct K { }; // { dg-message "DataMembers::I::K' defined as 'struct' here" }
+
+ class J j0;
+ class K k0; // { dg-warning "DataMembers::I::K' declared with a mismatched class-key" }
+
+ struct J j1; // { dg-warning "DataMembers::I::J' declared with a mismatched class-key" }
+ struct K k1;
+};
+} // namespace DataMembers
+
+
+namespace Templates
+{
+template <int> class A;
+template <int> class A;
+
+template <int> struct B;
+template <int> struct B;
+
+template <int> union C;
+template <int> union C;
+
+template <int> struct D; // { dg-warning "Templates::D\[^\n\r]*' declared with a mismatched class-key" }
+template <int>
+class D // { dg-message "Templates::D\[^\n\r]*' defined as 'class' here" }
+{ public: D (); };
+
+template <int> class E; // { dg-warning "Templates::E\[^\n\r]*' declared with a mismatched class-key" }
+template <int>
+struct E // { dg-message "Templates::E\[^\n\r]*' defined as 'struct' here" }
+{ int i; };
+
+template <int> class D;
+template <int> struct E;
+
+template <int>
+struct D; // { dg-warning "Templates::D\[^\n\r]*' declared with a mismatched class-key" }
+ // { dg-message "replace the class-key with 'class'" "hint" { target *-*-* } .-1 }
+} // namespace Templates
+
+
+namespace ExplicitSpecializations
+{
+template <int> class A;
+template <> class A<0>;
+template <> struct A<1>;
+template <> struct A<1> { };
+
+template <int> struct B;
+template <> struct B<0>;
+template <> class B<1>;
+template <> class B<2> { public: B (); };
+
+template <int> union C;
+template <> union C<0>;
+
+template <int> class D;
+template <> class D<0>; // { dg-warning "ExplicitSpecializations::D\[^\n\r]*' declared with a mismatched class-key " }
+template <>
+struct D<0> { }; // { dg-message "ExplicitSpecializations::D\[^\n\r]*' defined as 'struct' here" }
+
+template <int> struct E;
+template <> struct E<0>; // { dg-warning "ExplicitSpecializations::E\[^\n\r]*' declared with a mismatched class-key" }
+template <>
+class E<0> { }; // { dg-message "ExplicitSpecializations::E\[^\n\r]*' defined as 'class' here" }
+
+template <int> struct F;
+template <> class F<0> { }; // { dg-message "ExplicitSpecializations::F\[^\n\r]*' defined as 'class' here" }
+
+template <>
+struct F<0>; // { dg-warning "ExplicitSpecializations::F\[^\n\r]*' declared with a mismatched class-key" }
+} // namespace ExplicitSpecializations
+
+
+namespace PartialSpecializations
+{
+template <class> class A;
+template <class T> struct A<const T>;
+template <class T> struct A<volatile T>;
+
+template <class> struct B;
+template <class T> class B<const T>;
+template <class T> class B<volatile T>;
+
+template <class> class C { };
+template <class T> struct C<const T> { };
+template <class T> struct C<volatile T> { };
+
+template <class> struct D { };
+template <class T> class D<const T> { };
+template <class T> class D<volatile T> { };
+
+template <class> class E;
+template <class T>
+struct E<const T>; // { dg-message "PartialSpecializations::E<const T>' first declared as 'struct' here" }
+
+template <class T>
+class E<const T>; // { dg-warning "PartialSpecializations::E<const T>' declared with a mismatched class-key" }
+
+template <class> class F;
+template <class T>
+class F<const T>; // { dg-message "PartialSpecializations::F<const T>' first declared as 'class' here" }
+template <class T>
+struct F<const T>; // { dg-warning "PartialSpecializations::F<const T>' declared with a mismatched class-key" }
+} // namespace PartialSpecializations
+
+
+namespace Classes
+{
+struct G;
+
+class G; // { dg-warning "Classes::G' declared with a mismatched class-key 'class'" }
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wredundant-tags.C b/gcc/testsuite/g++.dg/warn/Wredundant-tags.C
new file mode 100644
index 00000000000..ac5afa912a1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wredundant-tags.C
@@ -0,0 +1,128 @@
+/* PR c++/61339 - add mismatch between struct and class
+ Test to verify that -Wredundant-tags is issued for references to class
+ types that use the class-key even though they don't need to.
+ { dg-do compile }
+ { dg-options "-Wredundant-tags" } */
+
+struct A;
+
+extern A *pa;
+extern struct A *pa; // { dg-warning "redundant class-key 'struct' in reference to 'struct A'" }
+
+extern A aa[];
+extern struct A aa[]; // { dg-warning "redundant class-key 'struct' in reference to 'struct A'" }
+
+void func (A*);
+void func (struct A*); // { dg-warning "redundant class-key 'struct' in reference to 'struct A'" }
+
+int A;
+
+extern struct A *pa;
+extern struct A aa[];
+void func (struct A*);
+
+
+class B;
+
+extern B *pb;
+extern class B *pb; // { dg-warning "redundant class-key 'class' in reference to 'class B'" }
+
+extern B ab[];
+extern class B ab[]; // { dg-warning "redundant class-key 'class' in reference to 'class B'" }
+
+void func (B*);
+void func (class B*); // { dg-warning "redundant class-key 'class' in reference to 'class B'" }
+
+int B;
+
+extern class B *pb;
+extern class B ab[];
+void func (class B*);
+
+
+enum C { c0 };
+
+extern C *pc;
+extern enum C *pc; // { dg-warning "redundant enum-key 'enum' in reference to 'enum C'" }
+
+extern C ac[];
+extern enum C ac[]; // { dg-warning "redundant enum-key 'enum' in reference to 'enum C'" }
+
+void func (C*);
+void func (enum C*); // { dg-warning "redundant enum-key 'enum' in reference to 'enum C'" }
+
+int C;
+
+extern enum C *pc;
+extern enum C ac[];
+void func (enum C*);
+
+
+#if __cplusplus > 199711L
+
+enum class D1 { d1 };
+enum struct D2 { d2 };
+
+#else
+
+enum D1 { d1 };
+enum D2 { d2 };
+
+#endif
+
+extern D1 *pd1;
+extern D2 *pd2;
+extern enum D1 *pd1; // { dg-warning "redundant enum-key 'enum' in reference to 'enum class D1'" "C++ 11 and above" { target c++11 } }
+ // { dg-warning "redundant enum-key 'enum' in reference to 'enum D1'" "C++ 98" { target c++98_only } .-1 }
+
+extern enum D2 *pd2; // { dg-warning "redundant enum-key 'enum' in reference to 'enum class D2'" "C++ 11 and above" { target c++11 } }
+ // { dg-warning "redundant enum-key 'enum' in reference to 'enum D2'" "C++ 98" { target c++98_only } .-1 }
+
+extern D1 ad1[];
+extern D2 ad2[];
+
+#if __cplusplus > 199711L
+extern enum class D1 ad1[]; // { dg-warning "redundant enum-key 'enum class' in reference to 'enum class D1'" "C++ 11 and above" { target c++11 } }
+ // { dg-warning "elaborated-type-specifier for a scoped enum must not use the 'class' keyword" "C++ 11 and above" { target c++11 } .-1 }
+/* The pretty printer cannot differentiate between enum class and enum struct
+ because the C++ front-end doesn't encode it so allow for both in the text
+ of the warning below. */
+extern enum struct D2 ad2[]; // { dg-warning "redundant enum-key 'enum struct' in reference to 'enum \(class|struct\) D2'" "C++ 11 and above" { target c++11 } }
+ // { dg-warning "elaborated-type-specifier for a scoped enum must not use the 'struct' keyword" "C++ 11 and above" { target c++11 } .-1 }
+#else
+extern enum D1 ad1[]; // { dg-warning "redundant enum-key 'enum' in reference to 'enum D1'" "C++ 98" { target c++98_only } }
+#endif
+
+void func (D1*);
+void func (enum D1*); // { dg-warning "redundant enum-key 'enum' in reference to 'enum " }
+
+void func (D2*);
+void func (enum D2*); // { dg-warning "redundant enum-key 'enum' in reference to 'enum " }
+
+int D1, D2;
+
+extern enum D1 *pd1;
+extern enum D1 ad1[];
+void func (enum D1*);
+
+extern enum D2 *pd2;
+extern enum D2 ad2[];
+void func (enum D2*);
+
+
+union U;
+
+extern U *pu;
+extern union U *pu; // { dg-warning "redundant class-key 'union' in reference to 'union U'" }
+
+extern U au[];
+extern union U au[]; // { dg-warning "redundant class-key 'union' in reference to 'union U'" }
+
+void func (U*);
+void func (union U*); // { dg-warning "redundant class-key 'union' in reference to 'union U'" }
+
+int U;
+
+extern union U *pu;
+extern union U au[];
+void func (union U*);
