• =?UTF-8?B?Ikx1w61z?= Marques" (9/9) Sep 10 2013 I know that extern(C) functions cannot be legally overloaded, but
• =?UTF-8?B?Ikx1w61z?= Marques" (10/10) Sep 10 2013 I just realized I wasn't clear -- it calls the (wrong) overloaded
• Dicebot (3/13) Sep 10 2013 This is why mixing ABI and mangling in one entity is bad. And why
• Jacob Carlborg (5/7) Sep 11 2013 There's a GCC (Clang) extension that enables support function
• deadalnix (5/24) Sep 11 2013 I think this is another form of the unclear qualifier binding
• Dicebot (3/7) Sep 11 2013 Yeah, giving tool to differ those can be an elegant way out of
• David Nadlinger (10/12) Sep 10 2013 I agree that this should not be legal. LDC detects this in the

=?UTF-8?B?Ikx1w61z?= Marques" <luis luismarques.eu> writes:

I know that extern(C) functions cannot be legally overloaded, but 
not issuing an error in the following situation seems wrong / a 
bug:

     extern(C) void foo(int);
     extern(C) void foo() {}

     void main()
     {
         foo(42);
     }

=?UTF-8?B?Ikx1w61z?= Marques" <luis luismarques.eu> writes:

I just realized I wasn't clear -- it calls the (wrong) overloaded 
function:

     extern(C) void foo(int);
     extern(C) void foo() { writeln("yes, this is called"); }

     void main()
     {
         foo(42);
     }

outputs:

     yes, this is called

"Dicebot" <public dicebot.lv> writes:

On Tuesday, 10 September 2013 at 14:07:18 UTC, Luís Marques wrote:
 I just realized I wasn't clear -- it calls the (wrong) 
 overloaded function:

     extern(C) void foo(int);
     extern(C) void foo() { writeln("yes, this is called"); }

     void main()
     {
         foo(42);
     }

 outputs:

     yes, this is called

This is why mixing ABI and mangling in one entity is bad. And why 
overloading extern(C) functions is compile-time error in C++.

Jacob Carlborg <doob me.com> writes:

On 2013-09-10 16:38, Dicebot wrote:

 This is why mixing ABI and mangling in one entity is bad. And why
 overloading extern(C) functions is compile-time error in C++.

There's a GCC (Clang) extension that enables support function 
overloading in C. I guess it's a bit overkill to support in D.

-- 
/Jacob Carlborg

"deadalnix" <deadalnix gmail.com> writes:

On Tuesday, 10 September 2013 at 14:38:56 UTC, Dicebot wrote:
 On Tuesday, 10 September 2013 at 14:07:18 UTC, Luís Marques 
 wrote:
 I just realized I wasn't clear -- it calls the (wrong) 
 overloaded function:

    extern(C) void foo(int);
    extern(C) void foo() { writeln("yes, this is called"); }

    void main()
    {
        foo(42);
    }

 outputs:

    yes, this is called

 This is why mixing ABI and mangling in one entity is bad. And 
 why overloading extern(C) functions is compile-time error in 
 C++.

I think this is another form of the unclear qualifier binding 
problem.

Qualifier bind to symbol : mangling.
Qualifier bind to type : calling convention.

"Dicebot" <public dicebot.lv> writes:

On Wednesday, 11 September 2013 at 08:26:02 UTC, deadalnix wrote:
 I think this is another form of the unclear qualifier binding 
 problem.

 Qualifier bind to symbol : mangling.
 Qualifier bind to type : calling convention.

Yeah, giving tool to differ those can be an elegant way out of 
this inconvenience.

"David Nadlinger" <code klickverbot.at> writes:

On Tuesday, 10 September 2013 at 14:04:58 UTC, Luís Marques wrote:
     extern(C) void foo(int);
     extern(C) void foo() {}

I agree that this should not be legal. LDC detects this in the 
glue layer (we would have to add a workaround for the 
corresponding LLVM restriction otherwise):

---
$ ldc2 test.d
test.d(4): Error: Function type does not match previously 
declared function with the same mangled name: foo
---

David