Bug report (incompatible pointers)

Dear GPC developers:

This is my first mail to the list, so first of all: THANKS for a GREAT pascal compiler!

However, the current version (970714; DJGPP version) cannot compile (correctly) some programs with user-defined types. The problem occurs in the following situation:

- Unit "u1" defined a type (say, myType) - Another unit, "u2", has a procedure with a parameter of type myType - The main program calls the procedure in "u2" (after having defined a variables of type myType).

I am sorry if this sounds cryptic (I tried to be precise), but there is an example below.

Now, this example/setup works if myType is a pointer to a built-in type, or an array of built-in types (ex: pointer to an array of doubles), but it does NOT work if myType is more "complicated", e.g. a pointer to a record type [as in the example below].

There is a similar (related) problem with procedural parameters (and types).

I have included a simple example (below) which demonstrates the bug, and I hope you are able to reproduce it. Note that the program consists of two units (u1, u2), as well as the main program.

Command line invoking GPC:

gpc -o mainprg.exe mainprg.pas --automake

Compiler output:

mainprg.pas: In function `program_Mainprg': mainprg.pas:14: warning: passing arg 1 of `Proc2' from incompatible pointer type

It is "only" a warning, and an .exe file is produces, but somestimes the program crashes (not here, though).

Sincerely,

Jesper Lund jel@hha.dk

P.S. If you respond to the list, please include a CC to me (I may not have been added the list yet). Thanks.

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program Mainprg;

uses u1, u2;

var y : RecPtr;

begin New (y);

Proc2 (y); { This call results in an incompatible pointer call } end. { Note that proc2 is in u2, where as recPtr is } { defined in u1. }

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unit u1;

interface

type rec = record a, b : Integer; end;

recPtr = ^rec;

procedure Proc1 (x : recPtr);

implementation

procedure Proc1 (x : recPtr); begin { Do nothing } end;

begin

end. { u1 }

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unit u2;

interface

uses u1;

procedure Proc2 (x : recPtr);

implementation

procedure Proc2 (x : recPtr); begin Proc1 (x); { This call is OK -- no compiler errors! } end;

begin

end. { u2 }

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