This patch fixes a bug in which if Ada.Containers.Vectors is instantiated with
an Index_Type such that Index_Type'Base'Last is less than Count_Type'Last, and
the -gnatwE switch is used, the compiler gives spurious error messages.
The following test should compile quietly with -gnatwE:
gnatmake short_vectors.ads -gnatwa -gnatwE -gnatf
with Ada.Containers.Vectors;
package Short_Vectors is
type Index_Type is range 1 .. 256;
package Map_Pkg is new Ada.Containers.Vectors
(Index_Type => Index_Type,
Element_Type => Integer);
end Short_Vectors;
Tested on x86_64-pc-linux-gnu, committed on trunk
2018-05-23 Bob Duff <d...@adacore.com>
gcc/ada/
* libgnat/a-convec.adb: (Insert, Insert_Space): Suppress warnings. The
code in question is not reachable in the case where Count_Type'Last is
out of range.
--- gcc/ada/libgnat/a-convec.adb
+++ gcc/ada/libgnat/a-convec.adb
@@ -999,9 +999,12 @@ package body Ada.Containers.Vectors is
-- We know that No_Index (the same as Index_Type'First - 1) is
-- less than 0, so it is safe to compute the following sum without
- -- fear of overflow.
+ -- fear of overflow. We need to suppress warnings, because
+ -- otherwise we get an error in -gnatwE mode.
+ pragma Warnings (Off);
Index := No_Index + Index_Type'Base (Count_Type'Last);
+ pragma Warnings (On);
if Index <= Index_Type'Last then
@@ -1657,9 +1660,12 @@ package body Ada.Containers.Vectors is
-- We know that No_Index (the same as Index_Type'First - 1) is
-- less than 0, so it is safe to compute the following sum without
- -- fear of overflow.
+ -- fear of overflow. We need to suppress warnings, because
+ -- otherwise we get an error in -gnatwE mode.
+ pragma Warnings (Off);
Index := No_Index + Index_Type'Base (Count_Type'Last);
+ pragma Warnings (On);
if Index <= Index_Type'Last then
