From: Piotr Trojanek Date: Mon, 3 Oct 2022 20:03:20 +0000 (+0200) Subject: ada: Support lock-free protected objects with pragma Initialize_Scalars X-Git-Tag: basepoints/gcc-14~3550 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ffcd1921e0aa37cf6b0fc6926bcadb0e988e4a2a;p=thirdparty%2Fgcc.git ada: Support lock-free protected objects with pragma Initialize_Scalars In general, protected subprograms are only eligible for a lock-free expansion if they do not reference global assignable objects. However, it seems reasonable to ignore references to variables in System.Scalar_Values, which are generated when pragma Initialize_Scalars is active. Such references appear, for example, when protected subprogram has formal parameters of mode out. gcc/ada/ * sem_ch9.adb (Satisfies_Lock_Free_Requirements): Ignore references to global variables inserted due to pragma Initialize_Scalars. --- diff --git a/gcc/ada/sem_ch9.adb b/gcc/ada/sem_ch9.adb index 5dee216256c1..e43e3ae0b416 100644 --- a/gcc/ada/sem_ch9.adb +++ b/gcc/ada/sem_ch9.adb @@ -474,6 +474,12 @@ package body Sem_Ch9 is begin -- Prohibit references to non-constant entities -- outside the protected subprogram scope. + -- + -- References to variables in System.Scalar_Values + -- generated because of pragma Initialize_Scalars are + -- allowed, because once those variables are + -- initialized by the binder-generated code, they + -- behave like constants. if Is_Assignable (Id) and then not @@ -482,6 +488,9 @@ package body Sem_Ch9 is Scope_Within_Or_Same (Scope (Id), Protected_Body_Subprogram (Sub_Id)) + and then not + (Is_RTU (Scope (Id), System_Scalar_Values) + and then not Comes_From_Source (N)) then if Lock_Free_Given then Error_Msg_NE