fix: valid compiler optimization may fail the test

cxa4001 may fail with "Exception not raised" when the compiler omits the
calls to To_Mapping, in accordance with 10.2.1(18/3):

  "If a library unit is declared pure, then the implementation is
  permitted to omit a call on a library-level subprogram of the library
  unit if the results are not needed after the call"

Using the result of both To_Mapping calls prevents the compiler from
omitting them.

"The corrected test will be available on the ACAA web site
(http://www.ada-auth.org/), and will be issued with the Modified Tests List
version 2.6K, 3.1DD, and 4.1GG."

gcc/testsuite/ChangeLog:

	* ada/acats/tests/cxa/cxa4001.a: Use function result.

1 files changed, 12 insertions, 0 deletions

diff --git a/gcc/testsuite/ada/acats/tests/cxa/cxa4001.a b/gcc/testsuite/ada/acats/tests/cxa/cxa4001.a
index d850acd..52fabc3 100644
--- a/gcc/testsuite/ada/acats/tests/cxa/cxa4001.a
+++ b/gcc/testsuite/ada/acats/tests/cxa/cxa4001.a
@@ -185,6 +185,12 @@ begin
       begin
          Bad_Map := Maps.To_Mapping(From => "aa", To => "yz");
          Report.Failed("Exception not raised with repeated character");
+
+         if Report.Equal (Character'Pos('y'),
+                          Character'Pos(Maps.Value(Bad_Map, 'a'))) then
+            -- Use the map to avoid optimization.
+            Report.Comment ("Shouldn't get here.");
+         end if;
       exception
          when Translation_Error => null;  -- OK
          when others            => 
@@ -200,6 +206,12 @@ begin
       begin
          Bad_Map := Maps.To_Mapping("abc", "yz");
          Report.Failed("Exception not raised with unequal parameter lengths");
+
+         if Report.Equal (Character'Pos('y'),
+                          Character'Pos(Maps.Value(Bad_Map, 'a'))) then
+            -- Use the map to avoid optimization.
+            Report.Comment ("Shouldn't get here.");
+         end if;
       exception
          when Translation_Error => null;  -- OK
          when others            =>