From b73547e40e0b2b6621feec59c9cc65312eddbc6d Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Mon, 24 Feb 2020 10:14:16 -0700 Subject: [PATCH] PR c++/93804 - exempt extern C headers from -Wredundant-tags gcc/cp/ChangeLog: PR c++/93804 * parser.c (cp_parser_check_class_key): Avoid issuing -Wredundant-tags in shared C/C++ code in headers. gcc/testsuite/ChangeLog: PR c++/93804 * g++.dg/warn/Wredundant-tags-4.C: New test. * g++.dg/warn/Wredundant-tags-5.C: New test. * g++.dg/warn/Wredundant-tags-5.h: New test. --- gcc/cp/ChangeLog | 6 ++ gcc/cp/parser.c | 64 +++++++++--- gcc/testsuite/ChangeLog | 7 ++ gcc/testsuite/g++.dg/warn/Wredundant-tags-4.C | 142 ++++++++++++++++++++++++++ gcc/testsuite/g++.dg/warn/Wredundant-tags-5.C | 109 ++++++++++++++++++++ gcc/testsuite/g++.dg/warn/Wredundant-tags-5.h | 80 +++++++++++++++ 6 files changed, 396 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/g++.dg/warn/Wredundant-tags-4.C create mode 100644 gcc/testsuite/g++.dg/warn/Wredundant-tags-5.C create mode 100644 gcc/testsuite/g++.dg/warn/Wredundant-tags-5.h diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index cc0929a..9c212d9 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-02-24 Martin Sebor + + PR c++/93804 + * parser.c (cp_parser_check_class_key): Avoid issuing -Wredundant-tags + in shared C/C++ code in headers. + 2020-02-24 Marek Polacek PR c++/93869 - ICE with -Wmismatched-tags. diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 01936e8..8e52fef 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -30837,15 +30837,31 @@ cp_parser_maybe_warn_enum_key (cp_parser *parser, location_t key_loc, /* 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 % in reference to %q#T", - (scoped_key == RID_CLASS ? " class" - : scoped_key == RID_STRUCT ? " struct" : ""), type); + if (decl != type_decl) + return; + + if (scoped_key != RID_CLASS + && scoped_key != RID_STRUCT + && current_lang_name != lang_name_cplusplus + && current_namespace == global_namespace) + { + /* Avoid issuing the diagnostic for apparently redundant (unscoped) + enum tag in shared C/C++ code in files (such as headers) included + in the main source file. */ + const line_map_ordinary *map = NULL; + linemap_resolve_location (line_table, key_loc, + LRK_MACRO_DEFINITION_LOCATION, + &map); + if (!MAIN_FILE_P (map)) + return; } + + gcc_rich_location richloc (key_loc); + richloc.add_fixit_remove (key_loc); + warning_at (&richloc, OPT_Wredundant_tags, + "redundant enum-key % 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 @@ -31005,6 +31021,13 @@ cp_parser_check_class_key (cp_parser *parser, location_t key_loc, && class_key != union_type) return; + /* Only consider the true class-keys below and ignore typename_type, + etc. that are not C++ class-keys. */ + if (class_key != class_type + && class_key != record_type + && class_key != union_type) + 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 @@ -31017,15 +31040,32 @@ cp_parser_check_class_key (cp_parser *parser, location_t key_loc, 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 + && class_key != class_type + && current_lang_name != lang_name_cplusplus + && current_namespace == global_namespace) + { + /* Avoid issuing the diagnostic for apparently redundant struct + and union class-keys in shared C/C++ code in files (such as + headers) included in the main source file. */ + const line_map_ordinary *map = NULL; + linemap_resolve_location (line_table, key_loc, + LRK_MACRO_DEFINITION_LOCATION, + &map); + if (!MAIN_FILE_P (map)) + key_redundant = false; + } + 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); + "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) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 6d5abbb..fae86eb 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2020-02-24 Martin Sebor + + PR c++/93804 + * g++.dg/warn/Wredundant-tags-4.C: New test. + * g++.dg/warn/Wredundant-tags-5.C: New test. + * g++.dg/warn/Wredundant-tags-5.h: New test. + 2020-02-24 David Malcolm * gcc.dg/analyzer/analyzer-verbosity-2a.c: New test. diff --git a/gcc/testsuite/g++.dg/warn/Wredundant-tags-4.C b/gcc/testsuite/g++.dg/warn/Wredundant-tags-4.C new file mode 100644 index 0000000..c56153a --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wredundant-tags-4.C @@ -0,0 +1,142 @@ +/* PR c++/93804 - exempt extern "C" headers from -Wredundant-tags + Verify that -Wredundant-tags is not issued for redundant class-key + in extern "C" references in a header file. + { dg-do compile } + { dg-options "-Wredundant-tags -ftrack-macro-expansion=0" } */ + +# 1 "Wredundant-tags-4.C" +# 1 "Wredundant-tags-4.h" 1 +# line 10 + +#if __cplusplus >= 201103L +# define enum_struct enum struct +#else +# define enum_struct class +#endif + +extern "C" { + + class C1 { }; + enum E1 { }; + enum_struct ES1 { }; + struct S1 { enum E1 e1; }; + union U1 { enum E1 e1; struct S1 s1; }; + + /* The warning should be issued for the class-key class even in + an extern "C" block. */ + void f0 (class C1); // { dg-warning "\\\[-Wredundant-tags" } + void f1 (enum E1); // { dg-bogus "\\\[-Wredundant-tags" } + + /* Ditto for a scoped enum. */ + void f2 (enum_struct ES1); // { dg-warning "\\\[-Wredundant-tags" } + // { dg-warning "must not use the 'struct' keyword" "enum struct" { target { c++11 } } .-1 } + + void f3 (struct S1); // { dg-bogus "\\\[-Wredundant-tags" } + void f4 (union U1); // { dg-bogus "\\\[-Wredundant-tags" } + + inline int + finline1 (class C1) // { dg-warning "\\\[-Wredundant-tags" } + { return sizeof (class C1); } // { dg-warning "\\\[-Wredundant-tags" } + + inline int + finline2 (enum E1) // { dg-bogus "\\\[-Wredundant-tags" } + { return sizeof (enum E1); } // { dg-bogus "\\\[-Wredundant-tags" } + + inline int + finline3 (enum_struct ES1) // { dg-warning "\\\[-Wredundant-tags" } + { return sizeof (ES1); } + + inline int + finline4 (struct S1) // { dg-bogus "\\\[-Wredundant-tags" } + { return sizeof (struct S1); } + + inline int + finline5 (union U1) // { dg-bogus "\\\[-Wredundant-tags" } + { return sizeof (union U1); } + + extern class C1 c1; // { dg-warning "\\\[-Wredundant-tags" } + extern enum E1 e1; // { dg-bogus "\\\[-Wredundant-tags" } + extern enum_struct ES1 es1; // { dg-warning "\\\[-Wredundant-tags" } + extern struct S1 s1; // { dg-bogus "\\\[-Wredundant-tags" } + extern union U1 u1; // { dg-bogus "\\\[-Wredundant-tags" } + + namespace N1 { + /* Verify that -Wredundant-tags is issued in a namespace enclosed + in an extern "C" block. (Such code cannot be shared with C.) */ + extern class C1 n1c1; // { dg-warning "\\\[-Wredundant-tags" } + extern enum E1 n1e1; // { dg-warning "\\\[-Wredundant-tags" } + extern enum_struct ES1 n1es1; // { dg-warning "\\\[-Wredundant-tags" } + extern struct S1 n1s1; // { dg-warning "\\\[-Wredundant-tags" } + extern union U1 n1u1; // { dg-warning "\\\[-Wredundant-tags" } + } +} // extern "C" + + +extern "C++" { + + class C2 { }; + enum E2 { }; + enum_struct ES2 { }; + struct S2 { + enum E2 e21; // { dg-warning "\\\[-Wredundant-tags" } + E2 e22; + enum_struct ES2 es21; // { dg-warning "\\\[-Wredundant-tags" } + ES2 es22; + }; + union U2 { }; + + void f5 (class C2); // { dg-warning "\\\[-Wredundant-tags" } + void f6 (enum E2); // { dg-warning "\\\[-Wredundant-tags" } + void f7 (enum_struct ES2); // { dg-warning "\\\[-Wredundant-tags" } + void f8 (struct S2); // { dg-warning "\\\[-Wredundant-tags" } + void f9 (union U2); // { dg-warning "\\\[-Wredundant-tags" } + + extern class C2 c2; // { dg-warning "\\\[-Wredundant-tags" } + extern enum E2 e2; // { dg-warning "\\\[-Wredundant-tags" } + extern enum_struct ES2 es2; // { dg-warning "\\\[-Wredundant-tags" } + extern struct S2 s2; // { dg-warning "\\\[-Wredundant-tags" } + extern union U2 u2; // { dg-warning "\\\[-Wredundant-tags" } +} // extern "C++" + + +namespace N { + +class C3 { }; +enum E3 { }; +enum_struct ES3 { }; +struct S3 { }; +union U3 { }; + +void f10 (class C3); // { dg-warning "\\\[-Wredundant-tags" } +void f11 (enum E3); // { dg-warning "\\\[-Wredundant-tags" } +void f12 (enum_struct ES3); // { dg-warning "\\\[-Wredundant-tags" } +void f13 (struct S3); // { dg-warning "\\\[-Wredundant-tags" } +void f14 (union U3); // { dg-warning "\\\[-Wredundant-tags" } + +extern class C3 c3; // { dg-warning "\\\[-Wredundant-tags" } +extern enum E3 e3; // { dg-warning "\\\[-Wredundant-tags" } +extern enum_struct ES3 es3; // { dg-warning "\\\[-Wredundant-tags" } +extern struct S3 s3; // { dg-warning "\\\[-Wredundant-tags" } +extern union U3 u3; // { dg-warning "\\\[-Wredundant-tags" } + +extern "C" { + + /* Verify that -Wredundant-tags is issued in an extern "C" block + enclosed within a namespace. (Such code cannot be shared with + C.) */ + class C4 { }; + enum E4 { }; + enum_struct ES4 { }; + struct S4 { }; + union U4 { }; + + extern class C4 c4; // { dg-warning "\\\[-Wredundant-tags" } + extern enum E4 e4; // { dg-warning "\\\[-Wredundant-tags" } + extern enum_struct ES4 es4; // { dg-warning "\\\[-Wredundant-tags" } + extern struct S4 s4; // { dg-warning "\\\[-Wredundant-tags" } + extern union U4 u4; // { dg-warning "\\\[-Wredundant-tags" } +} + +} // namespace N + +// { dg-prune-output "must not use the 'struct' keyword" } diff --git a/gcc/testsuite/g++.dg/warn/Wredundant-tags-5.C b/gcc/testsuite/g++.dg/warn/Wredundant-tags-5.C new file mode 100644 index 0000000..a3676d8 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wredundant-tags-5.C @@ -0,0 +1,109 @@ +// PR c++/93804 - exempt extern "C" headers from -Wredundant-tags +// Verify that -Wredundant-tags is issued even for redundant class-key +// in references in the main source file to extern "C" classes defined +// in headers. +// { dg-do compile } +// { dg-options "-Wredundant-tags -ftrack-macro-expansion=0" } + +#include "Wredundant-tags-5.h" + +extern "C" { + + class C1 // { dg-warning "\\\[-Wredundant-tags" } + fc1 (C1) + { + return C1 (); + } + + EC1 + fce1 (enum_class EC1) // { dg-warning "\\\[-Wredundant-tags" } + { + return EC1 (); + } + + E1 + fe1 (E1) + { + return (enum E1)0; // { dg-warning "\\\[-Wredundant-tags" } + } + + struct S1 // { dg-warning "\\\[-Wredundant-tags" } + fs1 (S1) + { + return S1 (); + } + + U1 + fu1 (union U1) // { dg-warning "\\\[-Wredundant-tags" } + { + return U1 (); + } + +} // extern "C" + + +extern "C++" { + + class C2 // { dg-warning "\\\[-Wredundant-tags" } + fc2 (C2) + { + return C2 (); + } + + EC2 + fce2 (enum_class EC2) // { dg-warning "\\\[-Wredundant-tags" } + { + return EC2 (); + } + + E2 + fe2 (E2) + { + return (enum E2)0; // { dg-warning "\\\[-Wredundant-tags" } + } + + struct S2 // { dg-warning "\\\[-Wredundant-tags" } + fs2 (S2) + { + return S2 (); + } + + U2 + fu2 (union U2) // { dg-warning "\\\[-Wredundant-tags" } + { + return U2 (); + } + +} // extern "C++" + + +class C3 // { dg-warning "\\\[-Wredundant-tags" } +fc3 (C3) +{ + return C3 (); +} + +EC3 +fce3 (enum_class EC3) // { dg-warning "\\\[-Wredundant-tags" } +{ + return EC3 (); +} + +E3 fe3 (E3) +{ + return (enum E3)0; // { dg-warning "\\\[-Wredundant-tags" } +} + +struct S3 // { dg-warning "\\\[-Wredundant-tags" } +fs3 (S3) +{ + return S3 (); +} + +U3 +fu3 (union U3) // { dg-warning "\\\[-Wredundant-tags" } +{ + return U3 (); +} + +// { dg-prune-output "must not use the 'class' keyword" } diff --git a/gcc/testsuite/g++.dg/warn/Wredundant-tags-5.h b/gcc/testsuite/g++.dg/warn/Wredundant-tags-5.h new file mode 100644 index 0000000..c72aee6 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wredundant-tags-5.h @@ -0,0 +1,80 @@ +#ifndef WREDUNDANT_TAGS_H +#define WREDUNDANT_TAGS_H + +#if __cplusplus >= 201103L +# define enum_class enum class +#else +# define enum_class class +#endif + +extern "C" { + + class C1 { }; + enum_class EC1 { }; + enum E1 { }; + struct S1 { }; + union U1 { }; + +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wredundant-tags" + class C1 fc1 (class C1); // -Wredundant-tags + enum_class EC1 fce1 (enum_class EC1); +#pragma GCC diagnostic pop + + enum E1 fe1 (enum E1); + struct S1 fs1 (struct S1); + union U1 fu1 (union U1); + + C1 fc1 (C1); + EC1 fce1 (EC1); + E1 fe1 (E1); + S1 fs1 (S1); + U1 fu1 (U1); +} + + +extern "C++" { + + class C2 { }; + enum_class EC2 { }; + enum E2 { }; + struct S2 { }; + union U2 { }; + +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wredundant-tags" + class C2 fc2 (class C2); // -Wredundant-tags + enum_class EC2 fce2 (enum_class EC2); // -Wredundant-tags + struct S2 fs2 (struct S2); // -Wredundant-tags + union U2 fu2 (union U2); // -Wredundant-tags +#pragma GCC diagnostic pop + + C2 fc2 (C2); + EC2 fce2 (EC2); + E2 fe2 (E2); + S2 fs2 (S2); + U2 fu2 (U2); +} + + +class C3 { }; +enum_class EC3 { }; +enum E3 { }; +struct S3 { }; +union U3 { }; + +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wredundant-tags" +class C3 fc3 (class C3); // -Wredundant-tags +enum_class EC3 fce3 (enum_class EC3); // -Wredundant-tags +struct S3 fs3 (struct S3); // -Wredundant-tags +union U3 fu3 (union U3); // -Wredundant-tags +#pragma GCC diagnostic pop + +C3 fc3 (C3); +EC3 fce3 (EC3); +E3 fe3 (E3); +S3 fs3 (S3); +U3 fu3 (U3); + +#endif // WREDUNDANT_TAGS_H -- 2.7.4