[Bug c++/86243] unknown attribute before throw causes hard error

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86243

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-07-02
                 CC|                            |msebor at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed.  GCC recognizes an attribute when it applies to other statements but
gets confused when it's applied to a throw expression statement as in comment
#0.

$ cat t.C && gcc -S t.C
int f ()
{
  [[unlikely]] return 0;
  [[unlikely]] { }

  [[unlikely]] throw 0;
}

t.C: In function ‘int f()’:
t.C:3:3: warning: attributes at the beginning of statement are ignored
[-Wattributes]
   [[unlikely]] return 0;
   ^
t.C:4:3: warning: attributes at the beginning of statement are ignored
[-Wattributes]
   [[unlikely]] { }
   ^
t.C:6:4: error: expected identifier before ‘[’ token
   [[unlikely]] throw 0;
    ^
t.C: In lambda function:
t.C:6:16: error: expected ‘{’ before ‘throw’
   [[unlikely]] throw 0;
                ^~~~~
t.C: In function ‘int f()’:
t.C:6:15: error: expected ‘;’ before ‘throw’
   [[unlikely]] throw 0;
               ^~~~~~
               ;