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-rw-r--r--gcc/ChangeLog21
-rw-r--r--gcc/c-decl.c64
-rw-r--r--gcc/c-parse.in90
-rw-r--r--gcc/c-tree.h43
-rw-r--r--gcc/testsuite/ChangeLog4
-rw-r--r--gcc/testsuite/gcc.dg/c99-tag-3.c59
-rw-r--r--gcc/testsuite/gcc.dg/declspec-14.c11
7 files changed, 246 insertions, 46 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cea88e1..465b25d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,24 @@
+2004-10-14 Joseph S. Myers <jsm@polyomino.org.uk>
+
+ * c-tree.h (enum c_typespec_kind, struct c_typespec,
+ parser_xref_tag): New.
+ (struct c_declspecs): Add tag_defined_p. Adjust definition of
+ typedef_p.
+ (declspecs_add_type): Adjust prototypes.
+ * c-parse.in (%union): Add tstype.
+ (typespec_nonattr, typespec_attr, typespec_reserved_nonattr,
+ typespec_reserved_attr, typespec_nonreserved_nonattr,
+ structsp_attr, structsp_nonattr): Change to tstype. Update
+ actions.
+ * c-decl.c (build_null_declspecs): Initialize tag_defined_p.
+ (declspecs_add_type): Update to take struct c_typespec argument.
+ Set tag_defined_p and typedef_p as appropriate.
+ (xref_tag): Rename to parser_xref_tag and replace by wrapper.
+ Update to return struct c_typespec.
+ (shadow_tag_warned): Don't let empty declarations with qualifiers
+ or storage class specifiers redeclare a tag if a previous
+ declaration is visible.
+
2004-10-13 Richard Henderson <rth@redhat.com>
PR debug/15860
diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index b548f85..30a154c 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -2696,8 +2696,6 @@ shadow_tag_warned (const struct c_declspecs *declspecs, int warned)
{
bool found_tag = false;
- pending_invalid_xref = 0;
-
if (declspecs->type && !declspecs->default_int_p && !declspecs->typedef_p)
{
tree value = declspecs->type;
@@ -2721,8 +2719,29 @@ shadow_tag_warned (const struct c_declspecs *declspecs, int warned)
warned = 1;
}
}
+ else if (!declspecs->tag_defined_p
+ && declspecs->storage_class != csc_none)
+ {
+ if (warned != 1)
+ pedwarn ("empty declaration with storage class specifier "
+ "does not redeclare tag");
+ warned = 1;
+ pending_xref_error ();
+ }
+ else if (!declspecs->tag_defined_p
+ && (declspecs->const_p
+ || declspecs->volatile_p
+ || declspecs->restrict_p))
+ {
+ if (warned != 1)
+ pedwarn ("empty declaration with type qualifier "
+ "does not redeclare tag");
+ warned = 1;
+ pending_xref_error ();
+ }
else
{
+ pending_invalid_xref = 0;
t = lookup_tag (code, name, 1);
if (t == 0)
@@ -2747,6 +2766,8 @@ shadow_tag_warned (const struct c_declspecs *declspecs, int warned)
warned = 1;
}
+ pending_invalid_xref = 0;
+
if (declspecs->inline_p)
{
error ("%<inline%> in empty declaration");
@@ -4877,11 +4898,13 @@ get_parm_info (bool ellipsis)
}
/* Get the struct, enum or union (CODE says which) with tag NAME.
- Define the tag as a forward-reference if it is not defined. */
+ Define the tag as a forward-reference if it is not defined.
+ Return a c_typespec structure for the type specifier. */
-tree
-xref_tag (enum tree_code code, tree name)
+struct c_typespec
+parser_xref_tag (enum tree_code code, tree name)
{
+ struct c_typespec ret;
/* If a cross reference is requested, look up the type
already defined for this tag and return it. */
@@ -4897,8 +4920,12 @@ xref_tag (enum tree_code code, tree name)
this would not work properly if we return the reference found.
(For example, with "struct foo" in an outer scope, "union foo;"
must shadow that tag with a new one of union type.) */
+ ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref);
if (ref && TREE_CODE (ref) == code)
- return ref;
+ {
+ ret.spec = ref;
+ return ret;
+ }
/* If no such tag is yet defined, create a forward-reference node
and record it as the "definition".
@@ -4921,7 +4948,18 @@ xref_tag (enum tree_code code, tree name)
pushtag (name, ref);
- return ref;
+ ret.spec = ref;
+ return ret;
+}
+
+/* Get the struct, enum or union (CODE says which) with tag NAME.
+ Define the tag as a forward-reference if it is not defined.
+ Return a tree for the type. */
+
+tree
+xref_tag (enum tree_code code, tree name)
+{
+ return parser_xref_tag (code, name).spec;
}
/* Make sure that the tag NAME is defined *in the current scope*
@@ -6643,6 +6681,7 @@ build_null_declspecs (void)
ret->storage_class = csc_none;
ret->non_sc_seen_p = false;
ret->typedef_p = false;
+ ret->tag_defined_p = false;
ret->explicit_signed_p = false;
ret->deprecated_p = false;
ret->default_int_p = false;
@@ -6698,8 +6737,9 @@ declspecs_add_qual (struct c_declspecs *specs, tree qual)
returning SPECS. */
struct c_declspecs *
-declspecs_add_type (struct c_declspecs *specs, tree type)
+declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec)
{
+ tree type = spec.spec;
specs->non_sc_seen_p = true;
if (TREE_DEPRECATED (type))
specs->deprecated_p = true;
@@ -6975,7 +7015,13 @@ declspecs_add_type (struct c_declspecs *specs, tree type)
specs->type = TREE_TYPE (t);
}
else if (TREE_CODE (type) != ERROR_MARK)
- specs->type = type;
+ {
+ if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref)
+ specs->tag_defined_p = true;
+ if (spec.kind == ctsk_typeof)
+ specs->typedef_p = true;
+ specs->type = type;
+ }
return specs;
}
diff --git a/gcc/c-parse.in b/gcc/c-parse.in
index e469677..7542c39 100644
--- a/gcc/c-parse.in
+++ b/gcc/c-parse.in
@@ -101,8 +101,8 @@ do { \
%union {long itype; tree ttype; void *otype; struct c_expr exprtype;
struct c_arg_info *arginfotype; struct c_declarator *dtrtype;
struct c_type_name *typenametype; struct c_parm *parmtype;
- struct c_declspecs *dsptype; enum tree_code code;
- location_t location; }
+ struct c_declspecs *dsptype; struct c_typespec tstype;
+ enum tree_code code; location_t location; }
/* All identifiers that are not reserved words
and are not declared typedefs in the current block */
@@ -202,9 +202,9 @@ do { \
%type <dsptype> declspecs_ts_nosa declspecs_nots_nosa
%type <dsptype> declspecs_nosc_ts declspecs_nosc_nots declspecs_nosc declspecs
%type <dsptype> maybe_type_quals_attrs
-%type <ttype> typespec_nonattr typespec_attr
-%type <ttype> typespec_reserved_nonattr typespec_reserved_attr
-%type <ttype> typespec_nonreserved_nonattr
+%type <tstype> typespec_nonattr typespec_attr
+%type <tstype> typespec_reserved_nonattr typespec_reserved_attr
+%type <tstype> typespec_nonreserved_nonattr
%type <ttype> offsetof_member_designator
%type <ttype> scspec SCSPEC STATIC TYPESPEC TYPE_QUAL maybe_volatile
@@ -226,7 +226,7 @@ do { \
%type <dtrtype> parm_declarator_starttypename parm_declarator_nostarttypename
%type <dtrtype> array_declarator
-%type <ttype> structsp_attr structsp_nonattr
+%type <tstype> structsp_attr structsp_nonattr
%type <ttype> component_decl_list component_decl_list2
%type <ttype> component_decl components components_notype component_declarator
%type <ttype> component_notype_declarator
@@ -1262,7 +1262,9 @@ typespec_attr:
typespec_reserved_nonattr:
TYPESPEC
- { OBJC_NEED_RAW_IDENTIFIER (1); }
+ { OBJC_NEED_RAW_IDENTIFIER (1);
+ $$.kind = ctsk_resword;
+ $$.spec = $1; }
| structsp_nonattr
;
@@ -1274,17 +1276,21 @@ typespec_nonreserved_nonattr:
TYPENAME
{ /* For a typedef name, record the meaning, not the name.
In case of `foo foo, bar;'. */
- $$ = lookup_name ($1); }
+ $$.kind = ctsk_typedef;
+ $$.spec = lookup_name ($1); }
@@ifobjc
| CLASSNAME protocolrefs
- { $$ = objc_get_protocol_qualified_type ($1, $2); }
+ { $$.kind = ctsk_objc;
+ $$.spec = objc_get_protocol_qualified_type ($1, $2); }
| OBJECTNAME protocolrefs
- { $$ = objc_get_protocol_qualified_type ($1, $2); }
+ { $$.kind = ctsk_objc;
+ $$.spec = objc_get_protocol_qualified_type ($1, $2); }
/* Make "<SomeProtocol>" equivalent to "id <SomeProtocol>"
- nisse@lysator.liu.se */
| non_empty_protocolrefs
- { $$ = objc_get_protocol_qualified_type (NULL_TREE, $1); }
+ { $$.kind = ctsk_objc;
+ $$.spec = objc_get_protocol_qualified_type (NULL_TREE, $1); }
@@end_ifobjc
| typeof '(' expr ')'
{ skip_evaluation--;
@@ -1292,11 +1298,17 @@ typespec_nonreserved_nonattr:
if (TREE_CODE ($3.value) == COMPONENT_REF
&& DECL_C_BIT_FIELD (TREE_OPERAND ($3.value, 1)))
error ("%<typeof%> applied to a bit-field");
- $$ = TREE_TYPE ($3.value);
- pop_maybe_used (variably_modified_type_p ($$, NULL_TREE)); }
+ $$.kind = ctsk_typeof;
+ $$.spec = TREE_TYPE ($3.value);
+ pop_maybe_used (variably_modified_type_p ($$.spec,
+ NULL_TREE)); }
| typeof '(' typename ')'
- { skip_evaluation--; in_typeof--; $$ = groktypename ($3);
- pop_maybe_used (variably_modified_type_p ($$, NULL_TREE)); }
+ { skip_evaluation--;
+ in_typeof--;
+ $$.kind = ctsk_typeof;
+ $$.spec = groktypename ($3);
+ pop_maybe_used (variably_modified_type_p ($$.spec,
+ NULL_TREE)); }
;
/* typespec_nonreserved_attr does not exist. */
@@ -1639,47 +1651,55 @@ enum_head:
structsp_attr:
struct_head identifier '{'
- { $$ = start_struct (RECORD_TYPE, $2);
+ { $<ttype>$ = start_struct (RECORD_TYPE, $2);
/* Start scope of tag before parsing components. */
}
component_decl_list '}' maybe_attribute
- { $$ = finish_struct ($<ttype>4, nreverse ($5),
- chainon ($1, $7)); }
+ { $$.spec = finish_struct ($<ttype>4, nreverse ($5),
+ chainon ($1, $7));
+ $$.kind = ctsk_tagdef; }
| struct_head '{' component_decl_list '}' maybe_attribute
- { $$ = finish_struct (start_struct (RECORD_TYPE, NULL_TREE),
- nreverse ($3), chainon ($1, $5));
+ { $$.spec = finish_struct (start_struct (RECORD_TYPE,
+ NULL_TREE),
+ nreverse ($3), chainon ($1, $5));
+ $$.kind = ctsk_tagdef;
}
| union_head identifier '{'
- { $$ = start_struct (UNION_TYPE, $2); }
+ { $<ttype>$ = start_struct (UNION_TYPE, $2); }
component_decl_list '}' maybe_attribute
- { $$ = finish_struct ($<ttype>4, nreverse ($5),
- chainon ($1, $7)); }
+ { $$.spec = finish_struct ($<ttype>4, nreverse ($5),
+ chainon ($1, $7));
+ $$.kind = ctsk_tagdef; }
| union_head '{' component_decl_list '}' maybe_attribute
- { $$ = finish_struct (start_struct (UNION_TYPE, NULL_TREE),
- nreverse ($3), chainon ($1, $5));
+ { $$.spec = finish_struct (start_struct (UNION_TYPE,
+ NULL_TREE),
+ nreverse ($3), chainon ($1, $5));
+ $$.kind = ctsk_tagdef;
}
| enum_head identifier '{'
- { $$ = start_enum ($2); }
+ { $<ttype>$ = start_enum ($2); }
enumlist maybecomma_warn '}' maybe_attribute
- { $$ = finish_enum ($<ttype>4, nreverse ($5),
- chainon ($1, $8)); }
+ { $$.spec = finish_enum ($<ttype>4, nreverse ($5),
+ chainon ($1, $8));
+ $$.kind = ctsk_tagdef; }
| enum_head '{'
- { $$ = start_enum (NULL_TREE); }
+ { $<ttype>$ = start_enum (NULL_TREE); }
enumlist maybecomma_warn '}' maybe_attribute
- { $$ = finish_enum ($<ttype>3, nreverse ($4),
- chainon ($1, $7)); }
+ { $$.spec = finish_enum ($<ttype>3, nreverse ($4),
+ chainon ($1, $7));
+ $$.kind = ctsk_tagdef; }
;
structsp_nonattr:
struct_head identifier
- { $$ = xref_tag (RECORD_TYPE, $2); }
+ { $$ = parser_xref_tag (RECORD_TYPE, $2); }
| union_head identifier
- { $$ = xref_tag (UNION_TYPE, $2); }
+ { $$ = parser_xref_tag (UNION_TYPE, $2); }
| enum_head identifier
- { $$ = xref_tag (ENUMERAL_TYPE, $2);
+ { $$ = parser_xref_tag (ENUMERAL_TYPE, $2);
/* In ISO C, enumerated types can be referred to
only if already defined. */
- if (pedantic && !COMPLETE_TYPE_P ($$))
+ if (pedantic && !COMPLETE_TYPE_P ($$.spec))
pedwarn ("ISO C forbids forward references to %<enum%> types"); }
;
diff --git a/gcc/c-tree.h b/gcc/c-tree.h
index f6e195f..18d200f 100644
--- a/gcc/c-tree.h
+++ b/gcc/c-tree.h
@@ -131,6 +131,39 @@ struct c_expr
enum tree_code original_code;
};
+/* A kind of type specifier. Note that this information is currently
+ only used to distinguish tag definitions, tag references and typeof
+ uses. */
+enum c_typespec_kind {
+ /* A reserved keyword type specifier. */
+ ctsk_resword,
+ /* A reference to a tag, previously declared, such as "struct foo".
+ This includes where the previous declaration was as a different
+ kind of tag, in which case this is only valid if shadowing that
+ tag in an inner scope. */
+ ctsk_tagref,
+ /* A reference to a tag, not previously declared in a visible
+ scope. */
+ ctsk_tagfirstref,
+ /* A definition of a tag such as "struct foo { int a; }". */
+ ctsk_tagdef,
+ /* A typedef name. */
+ ctsk_typedef,
+ /* An ObjC-specific kind of type specifier. */
+ ctsk_objc,
+ /* A typeof specifier. */
+ ctsk_typeof
+};
+
+/* A type specifier: this structure is created in the parser and
+ passed to declspecs_add_type only. */
+struct c_typespec {
+ /* What kind of type specifier this is. */
+ enum c_typespec_kind kind;
+ /* The specifier itself. */
+ tree spec;
+};
+
/* A storage class specifier. */
enum c_storage_class {
csc_none,
@@ -178,8 +211,12 @@ struct c_declspecs {
specifiers to be handled separately from storage class
specifiers.) */
BOOL_BITFIELD non_sc_seen_p : 1;
- /* Whether the type is specified by a typedef. */
+ /* Whether the type is specified by a typedef or typeof name. */
BOOL_BITFIELD typedef_p : 1;
+ /* Whether a struct, union or enum type either had its content
+ defined by a type specifier in the list or was the first visible
+ declaration of its tag. */
+ BOOL_BITFIELD tag_defined_p : 1;
/* Whether the type is explicitly "signed" or specified by a typedef
whose type is explicitly "signed". */
BOOL_BITFIELD explicit_signed_p : 1;
@@ -371,6 +408,7 @@ extern tree start_struct (enum tree_code, tree);
extern void store_parm_decls (void);
extern void store_parm_decls_from (struct c_arg_info *);
extern tree xref_tag (enum tree_code, tree);
+extern struct c_typespec parser_xref_tag (enum tree_code, tree);
extern int c_expand_decl (tree);
extern struct c_parm *build_c_parm (struct c_declspecs *, tree,
struct c_declarator *);
@@ -383,7 +421,8 @@ extern struct c_declarator *make_pointer_declarator (struct c_declspecs *,
struct c_declarator *);
extern struct c_declspecs *build_null_declspecs (void);
extern struct c_declspecs *declspecs_add_qual (struct c_declspecs *, tree);
-extern struct c_declspecs *declspecs_add_type (struct c_declspecs *, tree);
+extern struct c_declspecs *declspecs_add_type (struct c_declspecs *,
+ struct c_typespec);
extern struct c_declspecs *declspecs_add_scspec (struct c_declspecs *, tree);
extern struct c_declspecs *declspecs_add_attrs (struct c_declspecs *, tree);
extern struct c_declspecs *finish_declspecs (struct c_declspecs *);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 339f775..b31a43c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2004-10-14 Joseph S. Myers <jsm@polyomino.org.uk>
+
+ * gcc.dg/c99-tag-3.c, gcc.dg/declspec-14.c: New tests.
+
2004-10-14 Hans-Peter Nilsson <hp@axis.com>
PR target/17984
diff --git a/gcc/testsuite/gcc.dg/c99-tag-3.c b/gcc/testsuite/gcc.dg/c99-tag-3.c
new file mode 100644
index 0000000..12eff6e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c99-tag-3.c
@@ -0,0 +1,59 @@
+/* Test for handling of tags. "const struct foo;" and similar does
+ not redeclare an existing tag. */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors" } */
+
+/* Plain "struct s;" always declares a tag: the same as one declared
+ in that scope, or shadowing one from an outer scope. */
+struct s0;
+struct s0 { int a; };
+struct s0;
+void f (void) { struct s0; }
+
+/* A declaration with a qualifier or storage class specifier declares
+ the tag if no other declaration of it is visible. */
+const union u0; /* { dg-warning "warning: useless type qualifier in empty declaration" } */
+union u0 { long b; };
+
+extern struct s1; /* { dg-warning "warning: useless storage class specifier in empty declaration" } */
+
+/* But if a declaration of the tag is visible, whether at the same
+ scope or an outer scope, the declaration specifies the same type as
+ the previous declaration and does not redeclare the tag (C99
+ 6.7.2.3#8). Thus, as it does not declare a declarator, a tag or
+ the members of an enumeration, it is a constraint violation. */
+
+struct s2 { char x; };
+const struct s2; /* { dg-error "error: empty declaration with type qualifier does not redeclare tag" } */
+
+union u1;
+extern union u1; /* { dg-error "error: empty declaration with storage class specifier does not redeclare tag" } */
+
+union u2 { long b; };
+void g(void) { const union u2; } /* { dg-error "error: empty declaration with type qualifier does not redeclare tag" } */
+
+/* And it does not redeclare the tag either if the outer tag is the
+ wrong kind of tag. This also yields an error for the reference to
+ the wrong kind of tag in addition to the pedwarn for the empty
+ declaration. */
+
+union u3 { float v; };
+void h(void) { const struct u3; } /* { dg-error "'u3' defined as wrong kind of tag" } */
+/* { dg-error "error: empty declaration with type qualifier does not redeclare tag" "wrong tag empty" { target *-*-* } 42 } */
+
+/* However, such useless specifiers are OK if the contents of the tag
+ are being defined, or shadowed in an inner scope with the contents
+ included in the shadowing. */
+
+struct s3;
+const struct s3 { int a; }; /* { dg-warning "warning: useless type qualifier in empty declaration" } */
+
+union u4;
+extern union u4 { int z; }; /* { dg-warning "warning: useless storage class specifier in empty declaration" } */
+
+enum e0 { E0 };
+void i(void) { const enum e0 { E1 }; } /* { dg-warning "warning: useless type qualifier in empty declaration" } */
+
+union u5 { int p; };
+void j(void) { extern struct u5 { int q; }; } /* { dg-warning "warning: useless storage class specifier in empty declaration" } */
diff --git a/gcc/testsuite/gcc.dg/declspec-14.c b/gcc/testsuite/gcc.dg/declspec-14.c
new file mode 100644
index 0000000..a19b9de
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/declspec-14.c
@@ -0,0 +1,11 @@
+/* Test that "typeof(struct foo)" and similar as declaration
+ specifiers act like typedef. */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+typeof(struct foo); /* { dg-warning "warning: useless type name in empty declaration" } */
+
+struct bar { int a; } x;
+
+typeof(x); /* { dg-warning "warning: useless type name in empty declaration" } */
generated by cgit v1.1 at 2025-05-31 05:50:24 +0000