• Nick Sabalausky (15/15) Oct 22 2011 I think I've misunderstood something about .di files:
• Andrej Mitrovic (3/3) Oct 22 2011 It's because the function is small enough to be inlineable, you can't
• Nick Sabalausky (5/8) Oct 22 2011 I hadn't expected that to happen without specifying -inline. But I guess...
• Andrew Wiley (7/11) Oct 22 2011 Interestingly, it looks like GNU ld should be able to inline functions a...
• Andrej Mitrovic (3/3) Oct 22 2011 It could also be considered a little bit dangerous. E.g. you could
• Nick Sabalausky (6/9) Oct 22 2011 ...Or specify different compilation options (like version identifiers) w...

"Nick Sabalausky" <a a.a> writes:

I think I've misunderstood something about .di files:

$ cat testDI.d
private int foo(){ return 1; }
$ dmd -H -c testDI.d
$ cat testDI.di
// D import file generated from 'testDI.d'
private int foo()
{
return 1;
}

Why does the .di file include the body of foo? In fact, why does it have foo 
at all? I thought the point of .di files was they just have the public 
declarations, not the bodies and not the private stuff. Well, except for 
templates, obviously, but this isn't a template.

What's going on? What am I misunderstanding?

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

It's because the function is small enough to be inlineable, you can't
inline it if you've only got the prototype in the header file. So it's
optimizations at play.

"Nick Sabalausky" <a a.a> writes:

"Andrej Mitrovic" <andrej.mitrovich gmail.com> wrote in message 
news:mailman.331.1319338165.24802.digitalmars-d-learn puremagic.com...
 It's because the function is small enough to be inlineable, you can't
 inline it if you've only got the prototype in the header file. So it's
 optimizations at play.

I hadn't expected that to happen without specifying -inline. But I guess 
this way makes sence since it lets the user app decide whether or not to 
inline.

Andrew Wiley <wiley.andrew.j gmail.com> writes:

On Sat, Oct 22, 2011 at 9:49 PM, Andrej Mitrovic <andrej.mitrovich gmail.com
 wrote:

 It's because the function is small enough to be inlineable, you can't
 inline it if you've only got the prototype in the header file. So it's
 optimizations at play.

Interestingly, it looks like GNU ld should be able to inline functions as
part of link time optimizations, which would make this unnecessary on
platforms where DMD uses ld. Probably not worth looking into right now, but
if di files become more used in the future, this sort of thing could
probably go away (except on Windows, but the linker situation there is
probably one of the most problematic parts of the D toolchain).

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

It could also be considered a little bit dangerous. E.g. you could
forget to regenerate header files after compilation and potentially
leave the user code with an old function body.

"Nick Sabalausky" <a a.a> writes:

"Andrej Mitrovic" <andrej.mitrovich gmail.com> wrote in message 
news:mailman.333.1319338819.24802.digitalmars-d-learn puremagic.com...
 It could also be considered a little bit dangerous. E.g. you could
 forget to regenerate header files after compilation and potentially
 leave the user code with an old function body.

...Or specify different compilation options (like version identifiers) when 
generating the lib/di versus when building your app. Which could leave a 
chimera of a module, a module built partially with one configuration and 
partially with another.