In some special cases involving class-wide pre/post conditions, Ada
allows a non-dispatching call to an abstract function (which is usually
illegal). Fix a bug in the implementation of Ada's rules about the
run-time behavior of such a call. Thanks to Javier Miranda for producing
this patch.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* contracts.adb (Build_Call_Helper_Body): Improve handling of
the case of a (legal) non-dispatching call to an abstract
subprogram.diff --git a/gcc/ada/contracts.adb b/gcc/ada/contracts.adb
--- a/gcc/ada/contracts.adb
+++ b/gcc/ada/contracts.adb
@@ -3899,7 +3899,16 @@ package body Contracts is
Set_Corresponding_Body (Helper_Decl, Body_Id);
Set_Must_Override (Body_Spec, False);
- if Present (Class_Preconditions (Subp_Id)) then
+ if Present (Class_Preconditions (Subp_Id))
+ -- Evaluate the expression if we are building a dynamic helper
+ -- or we are building a static helper for a non-abstract tagged
+ -- type; for abstract tagged types the helper just returns True
+ -- since it is called by the indirect call wrapper (ICW).
+ and then
+ (Is_Dynamic
+ or else
+ not Is_Abstract_Type (Find_Dispatching_Type (Subp_Id)))
+ then
Return_Expr :=
Copy_And_Update_References (Class_Preconditions (Subp_Id));
@@ -3910,7 +3919,8 @@ package body Contracts is
-- enabled.
else
- pragma Assert (Present (Ignored_Class_Preconditions (Subp_Id)));
+ pragma Assert (Present (Ignored_Class_Preconditions (Subp_Id))
+ or else Is_Abstract_Type (Find_Dispatching_Type (Subp_Id)));
Return_Expr := New_Occurrence_Of (Standard_True, Loc);
end if;
