From: Gary Dismukes Date: Wed, 13 Jul 2022 22:06:47 +0000 (-0400) Subject: [Ada] Error on return of object whose full view has undefaulted discriminants X-Git-Tag: basepoints/gcc-14~4836 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34d054d126f0fa870e36e37709199db84a5e1bd8;p=thirdparty%2Fgcc.git [Ada] Error on return of object whose full view has undefaulted discriminants The compiler wrongly reports an error about the expected type not matching the same-named found type in a return statement for a function whose result type has unknown discriminants when the full type is tagged and has an undefaulted discriminant, and the return expression is an object initialized by a function call. The processing for return statements that creates an actual subtype based on the return expression type's underlying type when that type has discriminants, and converts the expression to the actual subtype, should only be done when the underlying discriminated type is mutable (i.e., has defaulted discriminants). Otherwise the unchecked conversion to the actual subtype (of the underlying full type) can lead to a resolution problem later within Expand_Simple_Function_Return in the expansion of tag assignments (because the target type of the conversion is a full view and does not match the partial view of the function's result type). gcc/ada/ * exp_ch6.adb (Expand_Simple_Function_Return) Bypass creation of an actual subtype and unchecked conversion to that subtype when the underlying type of the expression has discriminants without defaults. --- diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb index fad130da350f..fe3bb5be28d0 100644 --- a/gcc/ada/exp_ch6.adb +++ b/gcc/ada/exp_ch6.adb @@ -6632,7 +6632,7 @@ package body Exp_Ch6 is begin if not Exp_Is_Function_Call - and then Has_Discriminants (Ubt) + and then Has_Defaulted_Discriminants (Ubt) and then not Is_Constrained (Ubt) and then not Has_Unchecked_Union (Ubt) then