Error with Opaque types in GNU Modula-2?

[Gaius Mulley]

Hi Kurt,

many thanks for the bug report.  Now fixed in the development trunk of
GCC.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118589

At some point after a suitable amount of testing it could be backported
onto gcc-14,

regards,
Gaius


$ cat opaquedefs.def 
DEFINITION MODULE opaquedefs ;  

TYPE
   OpaqueA ;
   OpaqueB ;   

END opaquedefs.

$ cat opaquedefs.mod 
(* { dg-do compile } *)
(* { dg-options "-g -c" } *)

IMPLEMENTATION MODULE opaquedefs ;

TYPE
   OpaqueA = POINTER TO CARDINAL ;
   OpaqueB = POINTER TO RECORD
                           width : CARDINAL ;
                           height: CARDINAL ;
                        END ;

END opaquedefs.

$ cat badopaque.mod 

(* { dg-do compile } *)
(* { dg-options "-g" } *)

MODULE badopaque ;  

FROM opaquedefs IMPORT OpaqueA ;

VAR
   a: OpaqueA ;
   c: CARDINAL ;
BEGIN
   c := 123 ;
   a^ := c     (* { dg-error "with an opaque type" }  *)
END badopaque.

$ gm2 -c badopaque.mod 
badopaque.mod:14:5: error: In program module ‘badopaque’: ‘a’ is declared with 
an opaque type from a different module and cannot be dereferenced
   14 |    a^ := c     (* { dg-error "with an opaque type" }  *)
      |     ^

$ cat badopaque2.mod 

(* { dg-do compile } *)
(* { dg-options "-g" } *)

MODULE badopaque2 ;  

FROM opaquedefs IMPORT OpaqueB ;

VAR
   b: OpaqueB ;
   c: CARDINAL ;
BEGIN
   c := 123 ;
   b^.width := c  (* { dg-bogus "unnamed" } *)
   (* { dg-error "cannot be dereferenced" "b^.width" { target *-*-* } 14 } *)   
   (* { dg-error "has no field" "no field" { target *-*-* } 14 } *)   
END badopaque2.

$ gm2 -c badopaque2.mod 
badopaque2.mod:14:5: error: In program module ‘badopaque2’: ‘b’ is declared 
with an opaque type from a different module and cannot be dereferenced
   14 |    b^.width := c  (* { dg-bogus "unnamed" } *)
      |     ^
badopaque2.mod:14:4: error: the type of ‘bad opaque pointer dereference’ is not 
a record (but ‘ADDRESS’) and therefore it has no field
   14 |    b^.width := c  (* { dg-bogus "unnamed" } *)
      |    ^~