Re: [PATCH v2] c++: Failure to delay noexcept parsing with ptr-operator [PR100752]

[Jason Merrill <jason@redhat.com>]

On 6/25/21 4:42 PM, Marek Polacek wrote:
> On Thu, Jun 10, 2021 at 10:31:33PM -0400, Jason Merrill wrote:
>> On 6/10/21 5:19 PM, Marek Polacek wrote:
>>> On Thu, Jun 10, 2021 at 03:09:29PM -0400, Jason Merrill wrote:
>>>> On 6/8/21 8:25 PM, Marek Polacek wrote:
>>>>> We weren't passing 'flags' to the recursive call to cp_parser_declarator
>>>>> in the ptr-operator case and as an effect, delayed parsing of noexcept
>>>>> didn't work as advertised.  The following change passes more than just
>>>>> CP_PARSER_FLAGS_DELAY_NOEXCEPT but that doesn't seem to break anything.
>>>>>
>>>>> I'm not passing member_p because I don't need it and because it breaks
>>>>> a few tests.
>>>>>
>>>>> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/branches?
>>>>>
>>>>> 	PR c++/100752
>>>>>
>>>>> gcc/cp/ChangeLog:
>>>>>
>>>>> 	* parser.c (cp_parser_declarator): Pass flags down to
>>>>> 	cp_parser_declarator.
>>>>>
>>>>> gcc/testsuite/ChangeLog:
>>>>>
>>>>> 	* g++.dg/cpp0x/noexcept69.C: New test.
>>>>> ---
>>>>>     gcc/cp/parser.c                         |  3 +--
>>>>>     gcc/testsuite/g++.dg/cpp0x/noexcept69.C | 12 ++++++++++++
>>>>>     2 files changed, 13 insertions(+), 2 deletions(-)
>>>>>     create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept69.C
>>>>>
>>>>> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
>>>>> index d59a829d0b9..5930990ec1c 100644
>>>>> --- a/gcc/cp/parser.c
>>>>> +++ b/gcc/cp/parser.c
>>>>> @@ -22066,8 +22066,7 @@ cp_parser_declarator (cp_parser* parser,
>>>>>     	cp_parser_parse_tentatively (parser);
>>>>>           /* Parse the dependent declarator.  */
>>>>> -      declarator = cp_parser_declarator (parser, dcl_kind,
>>>>> -					 CP_PARSER_FLAGS_NONE,
>>>>> +      declarator = cp_parser_declarator (parser, dcl_kind, flags,
>>>>>     					 /*ctor_dtor_or_conv_p=*/NULL,
>>>>>     					 /*parenthesized_p=*/NULL,
>>>>>     					 /*member_p=*/false,
>>>>
>>>> Should the other parameters also be passed down?  I'd think definitely
>>>> member_p and static_p, not sure about ctor_dtor_or_conv_p and
>>>> parenthesized_p.
>>>
>>> Hmm, as I mentioned in the patch description, I tried, but passing member_p
>>> broke a few tests and since it's not needed for this fix I gave up
>>> investigating why.  I could look into it if you're curious :).
>>
>> Please.
> 
> Turns out those were just trivial changes to the expected error messages.
> The following patch passes member_p and static_p too:
> 
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

OK.

> -- >8 --
> We weren't passing 'flags' to the recursive call to cp_parser_declarator
> in the ptr-operator case and as an effect, delayed parsing of noexcept
> didn't work as advertised.  The following change passes more than just
> CP_PARSER_FLAGS_DELAY_NOEXCEPT but that doesn't seem to break anything.
> 
> I'm now also passing member_p and static_p, as a consequence, two tests
> needed small tweaks.
> 
> 	PR c++/100752
> 
> gcc/cp/ChangeLog:
> 
> 	* parser.c (cp_parser_declarator): Pass flags down to
> 	cp_parser_declarator.  Also pass static_p/member_p.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/cpp0x/noexcept69.C: New test.
> 	* g++.dg/parse/saved1.C: Adjust dg-error.
> 	* g++.dg/template/crash50.C: Likewise.
> ---
>   gcc/cp/parser.c                         |  6 ++----
>   gcc/testsuite/g++.dg/cpp0x/noexcept69.C | 12 ++++++++++++
>   gcc/testsuite/g++.dg/parse/saved1.C     |  4 ++--
>   gcc/testsuite/g++.dg/template/crash50.C |  2 +-
>   4 files changed, 17 insertions(+), 7 deletions(-)
>   create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept69.C
> 
> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> index 096580e7e50..02daa7a6f6a 100644
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -22170,12 +22170,10 @@ cp_parser_declarator (cp_parser* parser,
>   	cp_parser_parse_tentatively (parser);
>   
>         /* Parse the dependent declarator.  */
> -      declarator = cp_parser_declarator (parser, dcl_kind,
> -					 CP_PARSER_FLAGS_NONE,
> +      declarator = cp_parser_declarator (parser, dcl_kind, flags,
>   					 /*ctor_dtor_or_conv_p=*/NULL,
>   					 /*parenthesized_p=*/NULL,
> -					 /*member_p=*/false,
> -					 friend_p, /*static_p=*/false);
> +					 member_p, friend_p, static_p);
>   
>         /* If we are parsing an abstract-declarator, we must handle the
>   	 case where the dependent declarator is absent.  */
> diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept69.C b/gcc/testsuite/g++.dg/cpp0x/noexcept69.C
> new file mode 100644
> index 00000000000..9b87ba0cafb
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept69.C
> @@ -0,0 +1,12 @@
> +// PR c++/100752
> +// { dg-do compile { target c++11 } }
> +
> +struct S {
> +  void f() noexcept {}
> +  S &g() noexcept(noexcept(f())) { f(); return *this; }
> +};
> +
> +struct X {
> +  int& f() noexcept(noexcept(i));
> +  int i;
> +};
> diff --git a/gcc/testsuite/g++.dg/parse/saved1.C b/gcc/testsuite/g++.dg/parse/saved1.C
> index 979a05676d2..1deaa93f516 100644
> --- a/gcc/testsuite/g++.dg/parse/saved1.C
> +++ b/gcc/testsuite/g++.dg/parse/saved1.C
> @@ -1,7 +1,7 @@
>   // Test that the parser doesn't go into an infinite loop from ignoring the
>   // PRE_PARSED_FUNCTION_DECL token.
>   
> -class C { static void* operator new(size_t); }; // { dg-error "24:declaration of .operator new. as non-function" }
> -// { dg-error "expected|ISO C\\+\\+ forbids" "" { target *-*-* } .-1 }
> +class C { static void* operator new(size_t); }; // { dg-error "37:.size_t. has not been declared" }
> +// { dg-error ".operator new. takes type .size_t." "" { target *-*-* } .-1 }
>   void* C::operator new(size_t) { return 0; } // { dg-error "" }
>   class D { D(int i): integer(i){}}; // { dg-error "" }
> diff --git a/gcc/testsuite/g++.dg/template/crash50.C b/gcc/testsuite/g++.dg/template/crash50.C
> index 286685ac838..4b846cdabc8 100644
> --- a/gcc/testsuite/g++.dg/template/crash50.C
> +++ b/gcc/testsuite/g++.dg/template/crash50.C
> @@ -3,5 +3,5 @@
>   
>   struct A
>   {
> -  template<int> void* foo(; // { dg-error "primary-expression|initialization|static|template" }
> +  template<int> void* foo(; // { dg-error "expected|initialization|static|template" }
>   };
> 
> base-commit: 74ebd1297e9cfa9f7d05bfcac5510d4968cc6ba8
>