* decl.c (gnat_to_gnu_entity) <E_Procedure>: Do not set "const" flag

[pf3gnuchains/gcc-fork.git] / gcc / ada / decl.c

diff --git a/gcc/ada/decl.c b/gcc/ada/decl.c
index c49e834..fac6f2f 100644 (file)
--- a/gcc/ada/decl.c
+++ b/gcc/ada/decl.c
@@ -3768,11 +3768,20 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
        if (TREE_CODE (gnu_return_type) == VOID_TYPE)
          pure_flag = false;
 
+       /* The semantics of "pure" in Ada essentially matches that of "const"
+          in the back-end.  In particular, both properties are orthogonal to
+          the "nothrow" property.  But this is true only if the EH circuitry
+          is explicit in the internal representation of the back-end.  If we
+          are to completely hide the EH circuitry from it, we need to declare
+          that calls to pure Ada subprograms that can throw have side effects
+          since they can trigger an "abnormal" transfer of control flow; thus
+          they can be neither "const" nor "pure" in the back-end sense.  */
        gnu_type
          = build_qualified_type (gnu_type,
-                                 (TYPE_QUALS (gnu_type)
-                                  | (TYPE_QUAL_CONST * pure_flag)
-                                  | (TYPE_QUAL_VOLATILE * volatile_flag)));
+                                 TYPE_QUALS (gnu_type)
+                                 | (Exception_Mechanism == Back_End_Exceptions
+                                    ? TYPE_QUAL_CONST * pure_flag : 0)
+                                 | (TYPE_QUAL_VOLATILE * volatile_flag));
 
        Sloc_to_locus (Sloc (gnat_entity), &input_location);
 
@@ -3841,6 +3850,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
                                            inline_flag, public_flag,
                                            extern_flag, attr_list,
                                            gnat_entity);
+
            DECL_STUBBED_P (gnu_decl)
              = Convention (gnat_entity) == Convention_Stubbed;
          }