From b63566a4045e9cc27f739c89f863dbfb9dbe7860 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Tue, 5 Nov 2019 18:53:53 -0500 Subject: [PATCH] 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 --- gcc/ChangeLog | 5 +++++ gcc/cp/ChangeLog | 7 +++++++ gcc/cp/call.c | 51 ++++++++++++++++++++++++------------------------ gcc/cp/typeck.c | 4 ++-- gcc/expmed.c | 2 ++ 5 files changed, 41 insertions(+), 28 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4312d125061..8ee23dd5986 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2019-10-26 Jason Merrill + + PR tree-optimization/91825 + * expmed.c: Reduce -Wmaybe-uninitialized to warning. + 2019-11-05 Jim Wilson PR middle-end/92263 diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 2085319bbc9..560896a1dd8 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,10 @@ +2019-09-15 Jason Merrill + + * 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 Use vec instead of raw array for built-in candidates. diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 2a1da3cc4e1..390a4c581e2 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -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); diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index bf2502a3686..50240537938 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -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 diff --git a/gcc/expmed.c b/gcc/expmed.c index f1975fe33fe..ff8554b1562 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -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 . */ +/* Work around tree-optimization/91825. */ +#pragma GCC diagnostic warning "-Wmaybe-uninitialized" #include "config.h" #include "system.h" -- 2.30.2