https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91825
--- Comment #8 from Jason Merrill <jason at gcc dot gnu.org> --- Author: jason Date: Tue Nov 5 23:53:53 2019 New Revision: 277864 URL: https://gcc.gnu.org/viewcvs?rev=277864&root=gcc&view=rev Log: 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. Modified: trunk/gcc/ChangeLog trunk/gcc/cp/ChangeLog trunk/gcc/cp/call.c trunk/gcc/cp/typeck.c trunk/gcc/expmed.c
