[Bug c++/50359] New: poor error message for an undeclared identifier in constructor

[Bug c++/50359] New: poor error message for an undeclared identifier in constructor

[rui.maciel at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50359

             Bug #: 50359
           Summary: poor error message for an undeclared identifier in
                    constructor
    Classification: Unclassified
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: rui.maciel@gmail.com


Consider the following code:

<code>
struct Foo
{
public:
        Foo(int);
};


Foo::Foo(undeclared)
{
}


int main(void)
{
        Foo f(1);

        return 0;
}
</code>

When compiling the above code, the following error message is shown:

<message>
main.c++:8:9: error: expected constructor, destructor, or type conversion
before ‘(’ token
</message>

Although the error consists of a poorly defined parameter, which may actually
be a simple typo, g++ complains instead about the code which was parsed before
the '(' token, which is actually (at least to the best of my knowledge)
correct.

It would be nice if GCC informed the user about an undeclared identifier
instead of throwing a cryptic message regarding the portion of the code which
is valid.

[Bug c++/50359] poor error message for an undeclared identifier in constructor

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50359

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-04-12
     Ever Confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-12 12:23:38 UTC ---
Confirmed. Clang doesn't do much better, but EDG is very good:


"ComeauTest.c", line 8: error: identifier "undeclared" is undefined
  Foo::Foo(undeclared)
           ^

"ComeauTest.c", line 8: error: no instance of overloaded function "Foo::Foo"
matches
          the specified type
  Foo::Foo(undeclared)
       ^

[Bug c++/50359] poor error message for an undeclared identifier in constructor

[rui.maciel at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50359

--- Comment #2 from Rui Maciel <rui.maciel at gmail dot com> 2012-05-08 13:33:57 UTC ---
This issue is still present in g++ 4.6.3.

[Bug c++/50359] poor error message for an undeclared identifier in constructor

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50359

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |manu at gcc dot gnu.org
      Known to fail|                            |4.7.1

--- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-05-09 11:10:21 UTC ---
And in G++ 4.8.0.

I guess this has something to do with tentative parsing, but someone would need
to launch GDB and investigate what goes wrong in detail.