Commit b63566a4 by Jason Merrill Committed by Jason Merrill

Fix conversions for built-in operator overloading candidates.

While working on C++20 operator<=>, I noticed that build_new_op_1 was doing
too much conversion when a built-in candidate was selected; the standard
says it should only perform user-defined conversions, and then leave the
normal operator semantics to handle any standard conversions.  This is
important for operator<=> because a comparison of two different unscoped
enums is ill-formed; if we promote the enums to int here, cp_build_binary_op
never gets to see the original operand types, so we can't give the error.

I'm also disabling -Wmaybe-uninitialized for expmed.c to avoid the bootstrap
failure from the last time I applied this patch.

	* call.c (build_new_op_1): Don't apply any standard conversions to
	the operands of a built-in operator.  Don't suppress conversions in
	cp_build_unary_op.
	* typeck.c (cp_build_unary_op): Do integral promotions for enums.

	PR tree-optimization/91825
	* expmed.c: Reduce -Wmaybe-uninitialized to warning.

From-SVN: r277864
parent 6fda5f49
2019-10-26 Jason Merrill <jason@redhat.com>
PR tree-optimization/91825
* expmed.c: Reduce -Wmaybe-uninitialized to warning.
2019-11-05 Jim Wilson <jimw@sifive.com>
PR middle-end/92263
2019-09-15 Jason Merrill <jason@redhat.com>
* call.c (build_new_op_1): Don't apply any standard conversions to
the operands of a built-in operator. Don't suppress conversions in
cp_build_unary_op.
* typeck.c (cp_build_unary_op): Do integral promotions for enums.
2019-11-04 Jason Merrill <jason@redhat.com>
Use vec instead of raw array for built-in candidates.
......
......@@ -6156,41 +6156,40 @@ build_new_op_1 (const op_location_t &loc, enum tree_code code, int flags,
break;
}
/* We need to strip any leading REF_BIND so that bitfields
don't cause errors. This should not remove any important
conversions, because builtins don't apply to class
objects directly. */
/* "If a built-in candidate is selected by overload resolution, the
operands of class type are converted to the types of the
corresponding parameters of the selected operation function,
except that the second standard conversion sequence of a
user-defined conversion sequence (12.3.3.1.2) is not applied." */
conv = cand->convs[0];
if (conv->kind == ck_ref_bind)
conv = next_conversion (conv);
arg1 = convert_like (conv, arg1, complain);
if (conv->user_conv_p)
{
while (conv->kind != ck_user)
conv = next_conversion (conv);
arg1 = convert_like (conv, arg1, complain);
}
if (arg2)
{
conv = cand->convs[1];
if (conv->kind == ck_ref_bind)
conv = next_conversion (conv);
else
arg2 = decay_conversion (arg2, complain);
/* We need to call warn_logical_operator before
converting arg2 to a boolean_type, but after
decaying an enumerator to its value. */
if (complain & tf_warning)
warn_logical_operator (loc, code, boolean_type_node,
code_orig_arg1, arg1,
code_orig_arg2, arg2);
arg2 = convert_like (conv, arg2, complain);
if (conv->user_conv_p)
{
while (conv->kind != ck_user)
conv = next_conversion (conv);
arg2 = convert_like (conv, arg2, complain);
}
}
if (arg3)
{
conv = cand->convs[2];
if (conv->kind == ck_ref_bind)
conv = next_conversion (conv);
convert_like (conv, arg3, complain);
if (conv->user_conv_p)
{
while (conv->kind != ck_user)
conv = next_conversion (conv);
arg3 = convert_like (conv, arg3, complain);
}
}
}
}
......@@ -6258,7 +6257,7 @@ build_new_op_1 (const op_location_t &loc, enum tree_code code, int flags,
case REALPART_EXPR:
case IMAGPART_EXPR:
case ABS_EXPR:
return cp_build_unary_op (code, arg1, candidates != 0, complain);
return cp_build_unary_op (code, arg1, false, complain);
case ARRAY_REF:
return cp_build_array_ref (input_location, arg1, arg2, complain);
......
......@@ -6298,7 +6298,7 @@ cp_build_unary_op (enum tree_code code, tree xarg, bool noconvert,
: _("wrong type argument to unary plus"));
else
{
if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
if (!noconvert && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
arg = cp_perform_integral_promotions (arg, complain);
/* Make sure the result is not an lvalue: a unary plus or minus
......@@ -6323,7 +6323,7 @@ cp_build_unary_op (enum tree_code code, tree xarg, bool noconvert,
| WANT_VECTOR_OR_COMPLEX,
arg, true)))
errstring = _("wrong type argument to bit-complement");
else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
else if (!noconvert && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
{
/* Warn if the expression has boolean value. */
if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE
......
......@@ -18,6 +18,8 @@ You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* Work around tree-optimization/91825. */
#pragma GCC diagnostic warning "-Wmaybe-uninitialized"
#include "config.h"
#include "system.h"
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment