OK.
On Wed, Jun 27, 2018 at 3:01 PM, David Malcolm <dmalc...@redhat.com> wrote:
> PR c++/86329 reports that the C++ frontend can offer bogus suggestions like:
>
> #include <string>
>
> int compare()
> {
> return __n1 - __n2;
> }
>
> suggested.cc: In function 'int compare()':
> suggested.cc:5:10: error: '__n1' was not declared in this scope
> return __n1 - __n2;
> ^~~~
> suggested.cc:5:10: note: suggested alternative: '._61'
> return __n1 - __n2;
> ^~~~
> ._61
> suggested.cc:5:17: error: '__n2' was not declared in this scope
> return __n1 - __n2;
> ^~~~
> suggested.cc:5:17: note: suggested alternative: '._72'
> return __n1 - __n2;
> ^~~~
> ._72
>
> The dot-prefixed names are an implementation detail of how we implement
> anonymous enums found in the header files, generated via
> anon_aggrname_format in make_anon_name.
>
> This patch uses anon_aggrname_p to filter them out when considering
> which names to suggest.
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu;
> adds 9 PASS results to g++.sum
>
> OK for trunk, gcc-8, gcc-7 branches?
>
> gcc/cp/ChangeLog:
> PR c++/86329
> * name-lookup.c (consider_binding_level): Filter out names that
> match anon_aggrname_p.
>
> gcc/testsuite/ChangeLog:
> PR c++/86329
> * g++.dg/lookup/pr86329.C: New test.
> ---
> gcc/cp/name-lookup.c | 5 +++++
> gcc/testsuite/g++.dg/lookup/pr86329.C | 11 +++++++++++
> 2 files changed, 16 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/lookup/pr86329.C
>
> diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
> index a30c374..6ec4e6e 100644
> --- a/gcc/cp/name-lookup.c
> +++ b/gcc/cp/name-lookup.c
> @@ -5786,6 +5786,11 @@ consider_binding_level (tree name, best_match <tree,
> const char *> &bm,
> if (!suggestion)
> continue;
>
> + /* Don't suggest names that are for anonymous aggregate types, as
> + they are an implementation detail generated by the compiler. */
> + if (anon_aggrname_p (suggestion))
> + continue;
> +
> const char *suggestion_str = IDENTIFIER_POINTER (suggestion);
>
> /* Ignore internal names with spaces in them. */
> diff --git a/gcc/testsuite/g++.dg/lookup/pr86329.C
> b/gcc/testsuite/g++.dg/lookup/pr86329.C
> new file mode 100644
> index 0000000..fc091ba
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/lookup/pr86329.C
> @@ -0,0 +1,11 @@
> +/* PR c++/86329: ensure we don't erroneously offer suggestions like "._0",
> + which are an implementation detail of how e.g. anonymous enums are
> + handled internally. */
> +
> +enum {NONEMPTY};
> +
> +int test()
> +{
> + return __0; // { dg-error "'__0' was not declared in this scope" }
> + // { dg-bogus "suggested alternative" "" { target *-*-* } .-1 }
> +}
> --
> 1.8.5.3
>
