diff options
Diffstat (limited to 'gcc/ada/exp_util.adb')
| -rw-r--r-- | gcc/ada/exp_util.adb | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb index 535ec4ca16e..564c11b6613 100644 --- a/gcc/ada/exp_util.adb +++ b/gcc/ada/exp_util.adb @@ -2761,6 +2761,7 @@ package body Exp_Util is N_SCIL_Dispatch_Table_Object_Init | N_SCIL_Dispatch_Table_Tag_Init | N_SCIL_Dispatching_Call | + N_SCIL_Membership_Test | N_SCIL_Tag_Init | N_Selected_Component | N_Signed_Integer_Type_Definition | @@ -3411,17 +3412,49 @@ package body Exp_Util is -------------------- procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is + W : Boolean := Warn; + -- Set False if warnings suppressed + begin if Present (N) then Remove_Warning_Messages (N); - if Warn then - Error_Msg_F - ("?this code can never be executed and has been deleted!", N); + -- Generate warning if appropriate + + if W then + + -- We suppress the warning if this code is under control of an + -- if statement, whose condition is a simple identifier, and + -- either we are in an instance, or warnings off is set for this + -- identifier. The reason for killing it in the instance case is + -- that it is common and reasonable for code to be deleted in + -- instances for various reasons. + + if Nkind (Parent (N)) = N_If_Statement then + declare + C : constant Node_Id := Condition (Parent (N)); + begin + if Nkind (C) = N_Identifier + and then + (In_Instance + or else (Present (Entity (C)) + and then Has_Warnings_Off (Entity (C)))) + then + W := False; + end if; + end; + end if; + + -- Generate warning if not suppressed + + if W then + Error_Msg_F + ("?this code can never be executed and has been deleted!", N); + end if; end if; -- Recurse into block statements and bodies to process declarations - -- and statements + -- and statements. if Nkind (N) = N_Block_Statement or else Nkind (N) = N_Subprogram_Body |