digitalmars.D.bugs - extern(Windows) alias bug

John C (13/13) May 29 2006 The following are not equivalent, though I can't understand why not.

Regan Heath (12/25) May 29 2006 At a wild guess.. doesn't the alias:

John C (16/53) May 30 2006 You may be right there. The reason why I wanted this to work is because

Walter Bright (3/20) Jun 02 2006 Try:

Lionello Lunesu (22/39) May 30 2006 I think you put the "extern" on the wrong place:

John C (5/52) May 30 2006 No, "extern" has to go before "alias". In your code the calling

Lionello Lunesu (4/8) May 30 2006 I stand corrected then :)

Walter Bright (3/20) Jun 02 2006 That's right. An alias does not modify the calling convention of

John C <johnch_atms hotmail.com> writes:

The following are not equivalent, though I can't understand why not.

template TFunc1() {
   extern(Windows) alias int function(int) TFunc1;
}

alias int function(int) funcA;
template TFunc2() {
   extern(Windows) alias funcA TFunc2;
}

void main() {
   writefln(TFunc1!().mangleof); // PWiZi
   writefln(TFunc2!().mangleof); // PFiZi
}

So the extern(Windows) gets applied to TFunc1, but not TFunc2.

May 29 2006

"Regan Heath" <regan netwin.co.nz> writes:

On Mon, 29 May 2006 22:50:23 +0100, John C <johnch_atms hotmail.com> wrote:
 The following are not equivalent, though I can't understand why not.

 template TFunc1() {
    extern(Windows) alias int function(int) TFunc1;
 }

 alias int function(int) funcA;
 template TFunc2() {
    extern(Windows) alias funcA TFunc2;
 }

 void main() {
    writefln(TFunc1!().mangleof); // PWiZi
    writefln(TFunc2!().mangleof); // PFiZi
 }

 So the extern(Windows) gets applied to TFunc1, but not TFunc2.

At a wild guess.. doesn't the alias:
   alias int function(int) funcA;

have an implicit "D calling convention" (extern(D)?) label/tag/specifier,  
eg.
   alias extern(D) int function(int) funcA;

so, the alias:
   extern(Windows) alias funcA TFunc2;

really reads something like:
   extern(Windows) alias extern(D) int function(int) TFunc2;

and maybe the later one overrules the former?

Regan

May 29 2006

John C <johnch_atms hotmail.com> writes:

Regan Heath wrote:
 On Mon, 29 May 2006 22:50:23 +0100, John C <johnch_atms hotmail.com> wrote:
 
 The following are not equivalent, though I can't understand why not.

 template TFunc1() {
    extern(Windows) alias int function(int) TFunc1;
 }

 alias int function(int) funcA;
 template TFunc2() {
    extern(Windows) alias funcA TFunc2;
 }

 void main() {
    writefln(TFunc1!().mangleof); // PWiZi
    writefln(TFunc2!().mangleof); // PFiZi
 }

 So the extern(Windows) gets applied to TFunc1, but not TFunc2.

 
 
 At a wild guess.. doesn't the alias:
   alias int function(int) funcA;
 
 have an implicit "D calling convention" (extern(D)?) 
 label/tag/specifier,  eg.
   alias extern(D) int function(int) funcA;
 
 so, the alias:
   extern(Windows) alias funcA TFunc2;
 
 really reads something like:
   extern(Windows) alias extern(D) int function(int) TFunc2;
 
 and maybe the later one overrules the former?
 
 Regan

You may be right there. The reason why I wanted this to work is because 
this doesn't:

template TFunc(T) {
   ...
}

TFunc!(extern(Windows) int function(int));

A nice workaround would have been to have another template apply the 
calling convention:

template ExternWindows(T) {
   extern(Windows) alias T ExternWindows;
}

TFunc!(ExternWindows!(int function(int, char*, char*, int));

I guess I'm now wondering why extern can't be used inline. It'd be 
useful in the above situation, and on anonymous function literals.

John.

May 30 2006

Walter Bright <newshound digitalmars.com> writes:

John C wrote:
 You may be right there. The reason why I wanted this to work is because 
 this doesn't:
 
 template TFunc(T) {
   ...
 }
 
 TFunc!(extern(Windows) int function(int));
 
 A nice workaround would have been to have another template apply the 
 calling convention:
 
 template ExternWindows(T) {
   extern(Windows) alias T ExternWindows;
 }
 
 TFunc!(ExternWindows!(int function(int, char*, char*, int));

Try:

	extern (Windows) alias int function(int) fp;

Jun 02 2006

Lionello Lunesu <lio lunesu.remove.com> writes:

John C wrote:
 The following are not equivalent, though I can't understand why not.
 
 template TFunc1() {
   extern(Windows) alias int function(int) TFunc1;
 }
 
 alias int function(int) funcA;
 template TFunc2() {
   extern(Windows) alias funcA TFunc2;
 }
 
 void main() {
   writefln(TFunc1!().mangleof); // PWiZi
   writefln(TFunc2!().mangleof); // PFiZi
 }
 
 So the extern(Windows) gets applied to TFunc1, but not TFunc2.

I think you put the "extern" on the wrong place:

template TFunc1() {
   alias extern(Windows) int function(int) TFunc1;
}

alias int function(int) funcA;
template TFunc2() {
   alias extern(Windows) funcA TFunc2;
}

alias extern(Windows) int function(int) funcB;
template TFunc3() {
   alias funcB TFunc3;
}

void main()
{
   writefln(TFunc1!().mangleof); // PFiZi
   writefln(TFunc2!().mangleof); // PFiZi
   writefln(funcA.mangleof); // PFiZi
   writefln(funcB.mangleof); // PFiZi
   writefln(TFunc3!().mangleof); // PFiZi
}

L.

May 30 2006

John C <johnch_atms hotmail.com> writes:

Lionello Lunesu wrote:
 John C wrote:
 
 The following are not equivalent, though I can't understand why not.

 template TFunc1() {
   extern(Windows) alias int function(int) TFunc1;
 }

 alias int function(int) funcA;
 template TFunc2() {
   extern(Windows) alias funcA TFunc2;
 }

 void main() {
   writefln(TFunc1!().mangleof); // PWiZi
   writefln(TFunc2!().mangleof); // PFiZi
 }

 So the extern(Windows) gets applied to TFunc1, but not TFunc2.

 
 
 I think you put the "extern" on the wrong place:
 
 template TFunc1() {
   alias extern(Windows) int function(int) TFunc1;
 }
 
 alias int function(int) funcA;
 template TFunc2() {
   alias extern(Windows) funcA TFunc2;
 }
 
 alias extern(Windows) int function(int) funcB;
 template TFunc3() {
   alias funcB TFunc3;
 }
 
 void main()
 {
   writefln(TFunc1!().mangleof); // PFiZi
   writefln(TFunc2!().mangleof); // PFiZi
   writefln(funcA.mangleof); // PFiZi
   writefln(funcB.mangleof); // PFiZi
   writefln(TFunc3!().mangleof); // PFiZi
 }
 
 L.

No, "extern" has to go before "alias". In your code the calling 
convention has been ignored. And mangleof shows that: 'F' signifies 
functions with the D calling convention, 'W' functions with the Windows 
calling convention.

May 30 2006

Lionello Lunesu <lio lunesu.remove.com> writes:

John C wrote:
 No, "extern" has to go before "alias". In your code the calling 
 convention has been ignored. And mangleof shows that: 'F' signifies 
 functions with the D calling convention, 'W' functions with the Windows 
 calling convention.

I stand corrected then :)
Too bad the compiler does not complain, I even compiled it with warnings on.

L.

May 30 2006

Walter Bright <newshound digitalmars.com> writes:

John C wrote:
 The following are not equivalent, though I can't understand why not.
 
 template TFunc1() {
   extern(Windows) alias int function(int) TFunc1;
 }
 
 alias int function(int) funcA;
 template TFunc2() {
   extern(Windows) alias funcA TFunc2;
 }
 
 void main() {
   writefln(TFunc1!().mangleof); // PWiZi
   writefln(TFunc2!().mangleof); // PFiZi
 }
 
 So the extern(Windows) gets applied to TFunc1, but not TFunc2.

That's right. An alias does not modify the calling convention of 
whatever it is calling. It cannot, it is just another name for it.

Jun 02 2006

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digitalmars.D.bugs - extern(Windows) alias bug