[Ada] Fix spurious violations of No_Secondary_Stack restriction

[Ada] Fix spurious violations of No_Secondary_Stack restriction

[Pierre-Marie de Rodat]

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Now that finalization and return on the secondary stack are decoupled, the
transient scopes created because of the former need not necessarily manage
the secondary stack and trigger a violation of the associated restriction.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* exp_ch7.adb (Wrap_Transient_Declaration): Propagate Uses_Sec_Stack
	to enclosing function if it does not return on the secondary stack.
	* exp_ch6.adb (Expand_Call_Helper): Call Establish_Transient_Scope
	with Manage_Sec_Stack set to True only when necessary.
	* sem_res.adb (Resolve_Call): Likewise.
	(Resolve_Entry_Call): Likewise.

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diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb
--- a/gcc/ada/exp_ch6.adb
+++ b/gcc/ada/exp_ch6.adb
@@ -4927,10 +4927,11 @@ package body Exp_Ch6 is
            and then
              (Ekind (Current_Scope) /= E_Loop
                or else Nkind (Parent (Call_Node)) /= N_Function_Call
-               or else not Is_Build_In_Place_Function_Call
-                             (Parent (Call_Node)))
+               or else not
+                 Is_Build_In_Place_Function_Call (Parent (Call_Node)))
          then
-            Establish_Transient_Scope (Call_Node, Manage_Sec_Stack => True);
+            Establish_Transient_Scope
+              (Call_Node, Returns_On_Secondary_Stack (Etype (Subp)));
          end if;
       end if;
    end Expand_Call_Helper;


diff --git a/gcc/ada/exp_ch7.adb b/gcc/ada/exp_ch7.adb
--- a/gcc/ada/exp_ch7.adb
+++ b/gcc/ada/exp_ch7.adb
@@ -10336,7 +10336,7 @@ package body Exp_Ch7 is
          --  reclamation is done by the caller.
 
          if Ekind (Curr_S) = E_Function
-           and then Requires_Transient_Scope (Etype (Curr_S))
+           and then Returns_On_Secondary_Stack (Etype (Curr_S))
          then
             null;
 


diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb
--- a/gcc/ada/sem_res.adb
+++ b/gcc/ada/sem_res.adb
@@ -6955,7 +6955,8 @@ package body Sem_Res is
         and then Requires_Transient_Scope (Etype (Nam))
         and then not Is_Ignored_Ghost_Entity (Nam)
       then
-         Establish_Transient_Scope (N, Manage_Sec_Stack => True);
+         Establish_Transient_Scope
+           (N, Returns_On_Secondary_Stack (Etype (Nam)));
 
          --  If the call appears within the bounds of a loop, it will be
          --  rewritten and reanalyzed, nothing left to do here.
@@ -8535,7 +8536,8 @@ package body Sem_Res is
       elsif Expander_Active
         and then Requires_Transient_Scope (Etype (Nam))
       then
-         Establish_Transient_Scope (N, Manage_Sec_Stack => True);
+         Establish_Transient_Scope
+           (N, Returns_On_Secondary_Stack (Etype (Nam)));
       end if;
 
       --  Now we know that this is not a call to a function that returns an