[Bug c++/57678] New: too many errors for bad template parameter

[Bug c++/57678] New: too many errors for bad template parameter

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57678

            Bug ID: 57678
           Summary: too many errors for bad template parameter
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: manu at gcc dot gnu.org

template<int N> int foo(int a) { return N; }

void bar(void)
{
    foo<x>(5);
}


triggers:

test.cpp:5:9: error: ‘x’ was not declared in this scope
     foo<x>(5);
         ^
test.cpp:5:13: error: no matching function for call to ‘foo(int)’
     foo<x>(5);
             ^
test.cpp:5:13: note: candidate is:
test.cpp:1:21: note: template<int N> int foo(int)
 template<int N> int foo(int a) { return N; }
                     ^
test.cpp:1:21: note:   template argument deduction/substitution failed:
test.cpp:5:13: error: template argument 1 is invalid
     foo<x>(5);
             ^

The second error is not useful (and the last "error" should be a note), why
even try to match the function call if the template argument was invalid?

Is there any case where the template argument is invalid and the invalidity is
not triggered by a previous error?

Clang:

test.cpp:5:9: error: use of undeclared identifier 'x'
    foo<x>(5);
        ^
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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/57678] too many errors for bad template parameter
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idW678

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think this is due to once a undeclared decl has been found, its type becomes
int which I think is just wrong.  We should use error_mark_node and then handle
the fall out from there.

There have been a few bugs with errors like this which points to the same issue
of treating undeclared decls as ints.

[Bug c++/57678] too many errors for bad template parameter

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57678

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-03-25
     Ever confirmed|0                           |1

[Bug c++/57678] too many errors for bad template parameter

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57678

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2015-09-08 00:00:00         |2021-8-1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Clang and ICC produce one error message.
GCC and MSVC produce two error messages.