Comparisons of composite objects may be internally transformed by the
frontend into a special kind of node that facilitates their internal
management. If processing the comparison causes the internal declaration
of a subtype declaration associated with some sub-expression, the backend
may crash when generating the code.
After this patch the following test compiles fine.
package Q is
type Rec (D : Positive) is record
S : String (1 .. D);
end record;
type Field_T is (One);
type Mask_T is array (Field_T) of Boolean;
function F return Rec;
end Q;
with Q; use Q;
procedure P (A : Rec) is
M : Mask_T;
use type Rec;
begin
M := (One => A /= F);
end;
Command: gcc -c p.adb
Tested on x86_64-pc-linux-gnu, committed on trunk
2017-04-25 Javier Miranda <mira...@adacore.com>
* sem_util.adb (New_Copy_Tree.Visit_Entity): Extend previous change
to generate new entities for subtype declarations located in
Expression_With_Action nodes.
Index: sem_util.adb
===================================================================
--- sem_util.adb (revision 247212)
+++ sem_util.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2017, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -17120,10 +17120,12 @@
pragma Assert (not Is_Itype (Old_Entity));
pragma Assert (Nkind (Old_Entity) in N_Entity);
- -- Restrict entity creation to variable declarations. There is no
- -- need to create variables declared in inner scopes.
+ -- Restrict entity creation to declarations of constants, variables
+ -- and subtypes. There is no need to duplicate entities declared in
+ -- inner scopes.
- if not Ekind_In (Old_Entity, E_Constant, E_Variable)
+ if (not Ekind_In (Old_Entity, E_Constant, E_Variable)
+ and then Nkind (Parent (Old_Entity)) /= N_Subtype_Declaration)
or else EWA_Inner_Scope_Level > 0
then
return;
