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

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

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>;
>