[C++ PATCH, PING^3] PR60531 - Wrong error about unresolved overloaded function

[Harald van Dijk <harald@gigawatt.nl>]

another ping

On 12/05/2019 17:57, Harald van Dijk wrote:
> ping again
> 
> On 26/04/2019 19:58, Harald van Dijk wrote:
>> ping
>>
>> On 13/04/2019 10:01, Harald van Dijk wrote:
>>> Hi,
>>>
>>> For PR60531, GCC wrongly rejects function templates with explicitly
>>> specified template arguments as overloaded. They are resolved by
>>> resolve_nondeduced_context, which is normally called by
>>> cp_default_conversion through decay_conversion, but the latter have
>>> extra effects making them unusable here. Calling the former directly
>>> does work.
>>>
>>> Bootstrapped on x86_64-pc-linux-gnu on top of r270264 with
>>> --enable-languages=all; make check shows no regressions.
>>>
>>> Does this look okay?
>>>
>>> This is my first code contribution to GCC, please let me know if
>>> anything is missing. I have not signed any copyright disclaimer or
>>> copyright assignment; <Contributing to GCC> says that is not necessary
>>> for small changes, which I trust this is. If it is needed after all,
>>> please let me know what specifically will be required.
>>>
>>> Cheers,
>>> Harald van Dijk
>>>
>>>      PR c++/60531
>>>      * typeck.c (cp_build_binary_op): See if overload can be resolved.
>>>      (cp_build_unary_op): Ditto.
>>>
>>>      * g++.dg/template/operator15.C: New test.
>>>
>>> diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
>>> index 03b14024738..e1ffe88ce2c 100644
>>> --- a/gcc/cp/typeck.c
>>> +++ b/gcc/cp/typeck.c
>>> @@ -4384,10 +4384,6 @@ cp_build_binary_op (const op_location_t &location,
>>>     /* True if both operands have arithmetic type.  */
>>>     bool arithmetic_types_p;
>>>
>>> -  /* Apply default conversions.  */
>>> -  op0 = orig_op0;
>>> -  op1 = orig_op1;
>>> -
>>>     /* Remember whether we're doing / or %.  */
>>>     bool doing_div_or_mod = false;
>>>
>>> @@ -4397,6 +4393,10 @@ cp_build_binary_op (const op_location_t &location,
>>>     /* Tree holding instrumentation expression.  */
>>>     tree instrument_expr = NULL_TREE;
>>>
>>> +  /* Apply default conversions.  */
>>> +  op0 = resolve_nondeduced_context (orig_op0, complain);
>>> +  op1 = resolve_nondeduced_context (orig_op1, complain);
>>> +
>>>     if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
>>>         || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
>>>         || code == TRUTH_XOR_EXPR)
>>> @@ -6204,11 +6204,13 @@ cp_build_unary_op (enum tree_code code, tree xarg, bool noconvert,
>>>     if (!arg || error_operand_p (arg))
>>>       return error_mark_node;
>>>
>>> +  arg = resolve_nondeduced_context (arg, complain);
>>> +
>>>     if ((invalid_op_diag
>>>          = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
>>>                       ? CONVERT_EXPR
>>>                       : code),
>>> -                   TREE_TYPE (xarg))))
>>> +                   TREE_TYPE (arg))))
>>>       {
>>>         if (complain & tf_error)
>>>       error (invalid_op_diag);
>>> diff --git a/gcc/testsuite/g++.dg/template/operator15.C b/gcc/testsuite/g++.dg/template/operator15.C
>>> new file mode 100644
>>> index 00000000000..755442266bb
>>> --- /dev/null
>>> +++ b/gcc/testsuite/g++.dg/template/operator15.C
>>> @@ -0,0 +1,6 @@
>>> +// PR c++/60531
>>> +
>>> +template < class T > T foo ();
>>> +
>>> +bool b1 = foo<int> == foo<int>;
>>> +int (*fp1)() = +foo<int>;
>>>