With this patch the compiler rejects properly a discrete range in a loop
specification that uses 'length by mistake.
Compiler lab4.adb must yield:
lab4.adb:13:23: expect attribute "range"
---
package body lab4 is
procedure createArray (myArr : in out dynArray; maxIndex : Integer) is
tempArr : dynArray (1..maxIndex);
cntArr : integer :=0;
begin
for i in tempArr'length loop
tempArr(cntArr):= cntArr;
cntArr := cntArr+1;
end loop;
end createArray;
end lab4;
---
package lab4 is
Type Node;
Type Tree is access Node;
Type Node is record
Val : Integer;
Left, Right : Tree;
end record;
type dynArray is array (positive range <>) of Integer; -- typeset for array
procedure createArray (myArr : in out dynArray; maxIndex : Integer);
end lab4;
Tested on x86_64-pc-linux-gnu, committed on trunk
2014-07-31 Ed Schonberg <[email protected]>
* sem_ch3.adb (Make_Index): Reject properly the use of 'Length
in a discrete range, when 'range was probably intended.
Index: sem_ch3.adb
===================================================================
--- sem_ch3.adb (revision 213338)
+++ sem_ch3.adb (working copy)
@@ -17285,10 +17285,16 @@
elsif Nkind (N) = N_Attribute_Reference then
- -- The parser guarantees that the attribute is a RANGE attribute
+ -- Catch beginner's error (use of attribute other than 'Range)
+ if Attribute_Name (N) /= Name_Range then
+ Error_Msg_N ("expect attribute ''Range", N);
+ Set_Etype (N, Any_Type);
+ return;
+ end if;
+
-- If the node denotes the range of a type mark, that is also the
- -- resulting type, and we do no need to create an Itype for it.
+ -- resulting type, and we do not need to create an Itype for it.
if Is_Entity_Name (Prefix (N))
and then Comes_From_Source (N)
