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| author | Marek Polacek <polacek@redhat.com> | 2024-02-02 14:53:01 -0500 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2024-02-10 08:22:59 -0500 |
| commit | cff174fabd6c980c09aee95db1d9d5c22421761f (patch) | |
| tree | 0adbe61835b14e2246101a6d5349e5f70d97ae5e /gcc/c-family | |
| parent | f88219333e85a05a98468f67d2f2190fc330044e (diff) | |
| download | gcc-cff174fabd6c980c09aee95db1d9d5c22421761f.zip gcc-cff174fabd6c980c09aee95db1d9d5c22421761f.tar.gz gcc-cff174fabd6c980c09aee95db1d9d5c22421761f.tar.bz2 | |
c++: DR2237, cdtor and template-id tweaks [PR107126]
Since my r11-532 changes to implement DR2237, for this test:
template<typename T>
struct S {
S<T>();
};
in C++20 we emit the ugly:
q.C:3:8: error: expected unqualified-id before ')' token
3 | S<T>();
which doesn't explain what the problem is. This patch improves that
diagnostic, reduces the error to a pedwarn, and adds a -Wc++20-compat
diagnostic. We now say:
q.C:3:7: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
3 | S<T>();
q.C:3:7: note: remove the '< >'
This patch also fixes
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97202#c8>
where the C++20 diagnostic was missing altogether: The problem was that I checked
for CPP_TEMPLATE_ID too early, at a point at which cp_parser_template_id may not
have been called yet. So let's check for it at the end of the function, after
the tentative parse and rollback.
-Wc++20-compat triggered in libitm/; I sent a patch for that.
DR 2237
PR c++/107126
PR c++/97202
gcc/c-family/ChangeLog:
* c-opts.cc (c_common_post_options): In C++20 or with -Wc++20-compat,
turn on -Wtemplate-id-cdtor.
* c.opt (Wtemplate-id-cdtor): New.
gcc/cp/ChangeLog:
* parser.cc (cp_parser_unqualified_id): Downgrade the DR2237 error to
a pedwarn.
(cp_parser_constructor_declarator_p): Likewise.
gcc/ChangeLog:
* doc/invoke.texi: Document -Wtemplate-id-cdtor.
gcc/testsuite/ChangeLog:
* g++.dg/DRs/dr2237.C: Adjust dg-error.
* g++.dg/parse/constructor2.C: Likewise.
* g++.dg/template/error34.C: Likewise.
* g++.old-deja/g++.pt/ctor2.C: Likewise.
* g++.dg/DRs/dr2237-2.C: New test.
* g++.dg/DRs/dr2237-3.C: New test.
* g++.dg/DRs/dr2237-4.C: New test.
* g++.dg/DRs/dr2237-5.C: New test.
* g++.dg/warn/Wtemplate-id-cdtor-1.C: New test.
* g++.dg/warn/Wtemplate-id-cdtor-2.C: New test.
* g++.dg/warn/Wtemplate-id-cdtor-3.C: New test.
* g++.dg/warn/Wtemplate-id-cdtor-4.C: New test.
Diffstat (limited to 'gcc/c-family')
| -rw-r--r-- | gcc/c-family/c-opts.cc | 5 | ||||
| -rw-r--r-- | gcc/c-family/c.opt | 4 |
2 files changed, 9 insertions, 0 deletions
diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc index b845aff..be3058d 100644 --- a/gcc/c-family/c-opts.cc +++ b/gcc/c-family/c-opts.cc @@ -998,6 +998,11 @@ c_common_post_options (const char **pfilename) warn_deprecated_enum_float_conv, cxx_dialect >= cxx20 && warn_deprecated); + /* -Wtemplate-id-cdtor is enabled by default in C++20. */ + SET_OPTION_IF_UNSET (&global_options, &global_options_set, + warn_template_id_cdtor, + cxx_dialect >= cxx20 || warn_cxx20_compat); + /* Declone C++ 'structors if -Os. */ if (flag_declone_ctor_dtor == -1) flag_declone_ctor_dtor = optimize_size; diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 9c0a280..b7a4a1a 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -1408,6 +1408,10 @@ Wtautological-compare C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn if a comparison always evaluates to true or false. +Wtemplate-id-cdtor +C++ ObjC++ Var(warn_template_id_cdtor) Warning +Warn about simple-template-id in a constructor or destructor. + Wterminate C++ ObjC++ Warning Var(warn_terminate) Init(1) Warn if a throw expression will always result in a call to terminate(). |