This patch removes a warning on a referenced entity with no explicit
prior assignment, if the type of the entity has
Preelaborable_Initialixation, such as Exception_Occurrence.
Tested on x86_64-pc-linux-gnu, committed on trunk
2019-07-22 Ed Schonberg <schonb...@adacore.com>
gcc/ada/
* sem_warn.adb (Check_References): Do not emit s warning on a
referenced entity with no explicit assignment if the type of the
entity has Preelaborable_Initialixation, such as
Exception_Occurrence.
gcc/testsuite/
* gnat.dg/warn25.adb: New testcase.--- gcc/ada/sem_warn.adb
+++ gcc/ada/sem_warn.adb
@@ -1413,9 +1413,13 @@ package body Sem_Warn is
goto Continue;
end if;
- -- Check for unset reference
+ -- Check for unset reference. If type of object has
+ -- preelaborable initialization, warning is misleading.
- if Warn_On_No_Value_Assigned and then Present (UR) then
+ if Warn_On_No_Value_Assigned
+ and then Present (UR)
+ and then not Known_To_Have_Preelab_Init (Etype (E1))
+ then
-- For other than access type, go back to original node to
-- deal with case where original unset reference has been
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/warn25.adb
@@ -0,0 +1,23 @@
+-- { dg-do compile }
+-- { dg-options "-gnatwa" }
+
+with Ada.Exceptions;
+procedure Warn25 is
+ CASA_Unavailable : Ada.Exceptions.Exception_Occurrence;
+ use Ada.Exceptions;
+begin
+ while True loop
+ declare
+ begin
+ if Exception_Identity (CASA_Unavailable) = Null_Id then
+ exit;
+ end if;
+ exception
+ when E : others =>
+ Save_Occurrence (Source => E, Target => CASA_Unavailable);
+ end;
+ end loop;
+ if Exception_Identity (CASA_Unavailable) /= Null_Id then
+ Reraise_Occurrence (CASA_Unavailable);
+ end if;
+end;
