https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123306
Bug ID: 123306
Summary: Mutably tagged types cause bug box when used as
generic arguments
Product: gcc
Version: 15.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ada
Assignee: unassigned at gcc dot gnu.org
Reporter: liam at liampwll dot com
CC: dkm at gcc dot gnu.org
Target Milestone: ---
Given the below sample program, a bug box is generated when a mutably tagged
type is used as an argument for a generic package. Tested on 15.2.1 and current
trunk. The stack trace from trunk also below indicates that Etype is returning
0 but I don't know enough about GNAT internals to debug beyond that:
| 16.0.0 20251225 (experimental) (x86_64-pc-linux-gnu) Assert_Failure failed
precondition from einfo-entities.ads:219|
| Error detected at example.adb:12:4 |
#7 0x0000000000bf1327 in einfo.utils.is_private_type (id=0) at
../../gcc/gcc/ada/einfo-utils.adb:371
#8 einfo.utils.root_type (id=12743) at ../../gcc/gcc/ada/einfo-utils.adb:2613
pragma Extensions_Allowed (All_Extensions);
procedure Example is
generic
type T is private;
package Foo is
end Foo;
type Mutably_Tagged is tagged null record with Size'Class => 128;
type Regular_Tagged is tagged null record;
package My_Foo is new Foo (Mutably_Tagged'Class); -- Bug box
-- package My_Foo is new Foo (Mutably_Tagged); -- Works
-- package My_Foo is new Foo (Regular_Tagged'Class); -- Errors, as
expected
begin
null;
end Example;
