diff mbox series

[Ada] Check scalar range in arrays constructed by concatenation

Message ID 20220107162701.GA948162@adacore.com
State Committed
Commit 34b8a9b8c094a43566fe4fbe0f9252dcd4d92e70
Headers
Series [Ada] Check scalar range in arrays constructed by concatenation |

Commit Message

Pierre-Marie de Rodat Jan. 7, 2022, 4:27 p.m. UTC 
  When concatenating scalars, we should check their range as in the
following example:

    type uint8 is range 0 .. 255;
    type Array_Type is array (Positive range <>) of uint8;

    Array_1 : Array_Type := 42 & 256;

This commit leads to emitting:
- a warning if a constraint error is expected but the scalar fits in the
  base type.
- an error if it does not fit in the base type

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

gcc/ada/

	* sem_res.adb (Resolve_Op_Concat_Arg): Check range when
	concatenating scalars.
diff mbox series

Patch

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
@@ -10185,7 +10185,7 @@  package body Sem_Res is
                        ("\\interpretation as call yields&", Arg, Typ);
                      Error_Msg_NE
                        ("\\interpretation as indexing of call yields&",
-                         Arg, Component_Type (Typ));
+                         Arg, Ctyp);
 
                   else
                      Error_Msg_N ("ambiguous operand for concatenation!", Arg);
@@ -10208,10 +10208,30 @@  package body Sem_Res is
                end;
             end if;
 
-            Resolve (Arg, Component_Type (Typ));
+            Resolve (Arg, Ctyp);
 
             if Nkind (Arg) = N_String_Literal then
-               Set_Etype (Arg, Component_Type (Typ));
+               Set_Etype (Arg, Ctyp);
+
+            elsif Is_Scalar_Type (Etype (Arg))
+              and then Compile_Time_Known_Value (Arg)
+            then
+               --  Determine if the out-of-range violation constitutes a
+               --  warning or an error according to the expression base type,
+               --  according to Ada 2022 RM 4.9 (35/2).
+
+               if Is_Out_Of_Range (Arg, Base_Type (Ctyp)) then
+                  Apply_Compile_Time_Constraint_Error
+                    (Arg, "value not in range of}", CE_Range_Check_Failed,
+                     Ent => Base_Type (Ctyp),
+                     Typ => Base_Type (Ctyp));
+
+               elsif Is_Out_Of_Range (Arg, Ctyp) then
+                  Apply_Compile_Time_Constraint_Error
+                    (Arg, "value not in range of}??", CE_Range_Check_Failed,
+                     Ent => Ctyp,
+                     Typ => Ctyp);
+               end if;
             end if;
 
             if Arg = Left_Opnd (N) then