[Bug c++/97200] New: error: use of local variable with automatic storage from containing function

[Bug c++/97200] New: error: use of local variable with automatic storage from containing function

[tangyixuan at mail dot dlut.edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97200

            Bug ID: 97200
           Summary: error: use of local variable with automatic storage
                    from containing function
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tangyixuan at mail dot dlut.edu.cn
  Target Milestone: ---

Hi, the following code seems valid. The structure 'S' contains a template
function 'func1' and return a member variable 'a'. However, gcc 11 rejects it
while clang accepts.

$ cat s.cpp

template <int> int func1(void) { 
  int  a; 
  struct S { 
    int func1(void){return a;} 
  };
}


$ g++ -c s.cpp
s.cpp: In member function ‘int func1()::S::func1()’:
s.cpp: error: use of local variable with automatic storage from containing
function
    4 |     int func1(void){return a;}
      |                            ^
s.cpp:2:8: note: ‘int a’ declared here
    2 |   int  a;
      |

[Bug c++/97200] error: use of local variable with automatic storage from containing function

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97200

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
clang rejects it as well as soon as you instantiate func1:

t3.ii:4:28: error: reference to local variable 'a' declared in enclosing
function 'func1<1>'
    int func1(void){return a;} 
                           ^
t3.ii:3:10: note: in instantiation of member function 'func1()::S::func1'
requested here
  struct S { 
         ^
t3.ii:8:14: note: in instantiation of function template specialization
'func1<1>' requested here
template int func1<1> ();
             ^
t3.ii:2:8: note: 'a' declared here
  int  a; 
       ^
1 error generated.


it looks like a correct error to me, not sure if the use of 'a' is dependent
and thus the error should be delayed to allow SFINAE (not sure if that exists
for function templates).

[Bug c++/97200] error: use of local variable with automatic storage from containing function

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97200

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 57346.

*** This bug has been marked as a duplicate of bug 57346 ***