www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - Error: Access Violation

reply "Brian Gardner" <briangr friberg.us> writes:
Why the program produced from the following code enters loop which ends with
the message: "Error: Access Violation"?

import std.c.stdio;

typedef u *u();

u *s()
{
 static int x = 0;
 printf("%d\n", x++);
 return s;
}

int main(){
 s();
 return 0;
}

For the below code the compiler (v0.119) reports "Internal error:
..\ztc\cgcod.c 1445":

import std.c.stdio;

typedef u *u();

u s()
{
 static int x = 0;
 printf("%d\n", x++);
 return s;
}

int main(){
 s();
 return 0;
}

Thank you,
Brian
Mar 23 2005
parent reply "Regan Heath" <regan netwin.co.nz> writes:
On Wed, 23 Mar 2005 20:00:36 +0200, Brian Gardner <briangr friberg.us>  
wrote:

 Why the program produced from the following code enters loop which ends  
 with
 the message: "Error: Access Violation"?

 import std.c.stdio;

 typedef u *u();

 u *s()
 {
  static int x = 0;
  printf("%d\n", x++);
  return s;
 }

 int main(){
  s();
  return 0;
 }


My guess is that the "return s;" statement in the "s" function calls the  
"s" function again.


 For the below code the compiler (v0.119) reports "Internal error:
 ..\ztc\cgcod.c 1445":

 import std.c.stdio;

 typedef u *u();

 u s()
 {
  static int x = 0;
  printf("%d\n", x++);
  return s;
 }

 int main(){
  s();
  return 0;
 }


This is a bug with DMD.

I have cross-posted my reply to the digitalmars.d.bugs group.

Regan
Mar 23 2005
next sibling parent reply Brian Gardner <Brian_member pathlink.com> writes:
In article <opsn4csyii23k2f5 nrage.netwin.co.nz>, Regan Heath says...

On Wed, 23 Mar 2005 20:00:36 +0200, Brian Gardner <briangr friberg.us>  
wrote:

 Why the program produced from the following code enters loop which ends  
 with
 the message: "Error: Access Violation"?

 import std.c.stdio;

 typedef u *u();

 u *s()
 {
  static int x = 0;
  printf("%d\n", x++);
  return s;
 }

 int main(){
  s();
  return 0;
 }


My guess is that the "return s;" statement in the "s" function calls the  
"s" function again.


Isn't s (in "return s;") a pointer to function according to D?
If not, how to obtain a pointer to function s without calling s?

Thanks,
Brian
Mar 24 2005
parent "Regan Heath" <regan netwin.co.nz> writes:
On Thu, 24 Mar 2005 13:55:07 +0000 (UTC), Brian Gardner  
<Brian_member pathlink.com> wrote:

 In article <opsn4csyii23k2f5 nrage.netwin.co.nz>, Regan Heath says...

 On Wed, 23 Mar 2005 20:00:36 +0200, Brian Gardner <briangr friberg.us>
 wrote:

 Why the program produced from the following code enters loop which ends
 with
 the message: "Error: Access Violation"?

 import std.c.stdio;

 typedef u *u();

 u *s()
 {
  static int x = 0;
  printf("%d\n", x++);
  return s;
 }

 int main(){
  s();
  return 0;
 }


 My guess is that the "return s;" statement in the "s" function calls the
 "s" function again.


 Isn't s (in "return s;") a pointer to function according to D?
 If not, how to obtain a pointer to function s without calling s?


http://www.digitalmars.com/d/function.html#closures

import std.stdio;

typedef fn function(int) fn;

fn foo(int i){
	writefln("foo called (",i,")");
	return &foo;
}

void main()
{
	fn p = foo(1);
	p(2);
}

Regan
Mar 25 2005
prev sibling next sibling parent =?ISO-8859-15?Q?Thomas_K=FChne?= writes:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Regan Heath wrote:

| On Wed, 23 Mar 2005 20:00:36 +0200, Brian Gardner <briangr friberg.us>
| wrote:

<snip>

|> For the below code the compiler (v0.119) reports "Internal error:
|> ..\ztc/cgcod.c 1445":
|>
|> import std.c.stdio;
|>
|> typedef u *u();
|>
|> u s()
|> {
|>  static int x = 0;
|>  printf("%d\n", x++);
|>  return s;
|> }
|>
|> int main(){
|>  s();
|>  return 0;
|> }
|
|
| This is a bug with DMD.
|
| I have cross-posted my reply to the digitalmars.d.bugs group.

Added to DStress as
http://dstress.kuehne.cn/nocompile/bug_cgcod_1445_A.d
http://dstress.kuehne.cn/nocompile/bug_cgcod_1445_B.d

Thomas

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0 (MingW32)

iD8DBQFCQ7bq3w+/yD4P9tIRAu66AJ47SC7gAsWS8WvgUHBHeX+xyEgQPACfWC0R
rBjJMWMONLVZ7f05AL4Pmu8=
=hqGj
-----END PGP SIGNATURE-----
Mar 24 2005
prev sibling parent "Walter" <newshound digitalmars.com> writes:
The trouble with both examples is the:

    typedef u *u();

which is a circular reference. The compiler now issues a diagnostic.
Apr 05 2005