gcc reports two different error messages, the second of them doesn't
seem to be correct. If it is somehow correct (I don't think so),
it is still misleading:
$ gnatmake -gnatv p.adb
gcc -c -gnatv p.adb
GNAT 4.3.0 20070127 (experimental)
Copyright 1992-2006, Free Software Foundation, Inc.
Compiling: p.adb (source file time stamp: 2007-01-27 13:38:37)
5. this.x := value;
|
>>> left hand side of assignment must be a variable
10. this.x := 42;
|
>>> assignment to "in" mode parameter not allowed
13 lines: 2 errors
gnatmake: "p.adb" compilation error
The first message is correct because "this" is a pointer to constant.
The second message should be the same because the parameter mode should
only affects the mode of the pointer parameter ("this") not the pointee.
(When T_Ptr is made access-to-variable, both lines compile fine.)
package P is
type T is tagged limited private;
type T_Ptr is access constant T; -- Note: constant
procedure reset(this: T_Ptr);
procedure set(this: T_Ptr; value: Integer);
private
type T is tagged limited record
x: Integer;
end record;
end P;
package body P is
procedure set(this: T_Ptr; value: Integer) is
begin
this.x := value;
end set;
procedure reset(this: T_Ptr) is
begin
this.x := 42;
end reset;
end P;
--
Summary: compiler puts the blame on in parameter mode, not
pointer to constant, for assignment to component
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: ada
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: bauhaus at futureapps dot de
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30614
