https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62042
--- Comment #12 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- https://gcc.gnu.org/g:b861785242450c8711aae6394751a75eadc4a0a9 commit r15-5129-gb861785242450c8711aae6394751a75eadc4a0a9 Author: Eric Botcazou <ebotca...@adacore.com> Date: Mon Oct 21 10:55:28 2024 +0200 ada: Elide the copy in aggregate returns for nonlimited types This implements elision of the copy operation for aggregate returns, i.e. simple return statements whose expression is an aggregate, in the case of nonlimited by-reference types (the copy operation is already elided for limited types), which comprise controlled and tagged types. This is the copy operation in the called function, that is to say the copy from the anonymous object built for the aggregate to the anonymous return object. The implementation simply extends that of limited types, which rewrites the simple return statement as an extended return statement internally and then leverages the built-in-place implementation of return objects for these statements. gcc/ada/ChangeLog: * exp_aggr.adb (Is_Build_In_Place_Aggregate_Return): Also return True for functions returning on the secondary stack or returning a by-reference type if the back end exposes its return slot. (Expand_Array_Aggregate): Call Is_Build_In_Place_Aggregate_Return to spot aggregates to be built in place. * exp_ch3.adb (Make_Allocator_For_Return): Add missing condition in assertion pragma deduced from Expand_Subtype_From_Expr. * exp_ch6.adb (Expand_Simple_Function_Return): Rewrite the statement as an extended return statement if the expression is an aggregate whose expansion is delayed. Properly relocate the expression in this case. * sem_ch6.adb: Add clauses for Exp_Aggr. (Analyze_Function_Return): Do not apply the predicate check to an aggregate whose expansion is delayed. Extended the processing of case expressions to all conditional expressions.
