• Ellery Newcomer (18/18) May 22 2013 In the context of shared libraries, with gcc
• Jacob Carlborg (5/23) May 22 2013 I don't know if it's automatically linked but here you go:
• Ellery Newcomer (2/5) May 23 2013 posix.mak makes no reference to it
• Jacob Carlborg (9/10) May 23 2013 Then I guess it's not used. Just compile it manually and link with it. I...
• Ellery Newcomer (2/10) May 24 2013 so don't document it :)
• Johannes Pfau (6/32) May 24 2013 LDC has got #pragma(LDC_global_crt_[c/d]tor) for this, see

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

In the context of shared libraries, with gcc

__attribute__((constructor))
void myfunc() { .. }

is used to make myfunc be called upon loading of the shared library (you 
can tell I know what I am talking about here) via some field in the ELF 
headers, apparently. Is there any way to get our trusty d compilers to 
do the equivalent?

Sure, Ellery, we have this awesome feature called module constructors. 
Check em out.

Ehh, I would be using this to initialize druntime...

You could just define _init, couldn't you?

Yes, but there is only one _init, while the above can be used with 
multiple functions and thus wouldn't inadvertently cause important code 
to not run. If I don't have to, I'd rather not.

Wait, why are you initializing druntime?

Because druntime isn't set up to do it yet for c main calling d shared 
lib. You'd think it would need the same sort of functionality when it 
does implement it, though.

Jacob Carlborg <doob me.com> writes:

On 2013-05-23 06:27, Ellery Newcomer wrote:
 In the context of shared libraries, with gcc

 __attribute__((constructor))
 void myfunc() { .. }

 is used to make myfunc be called upon loading of the shared library (you
 can tell I know what I am talking about here) via some field in the ELF
 headers, apparently. Is there any way to get our trusty d compilers to
 do the equivalent?

 Sure, Ellery, we have this awesome feature called module constructors.
 Check em out.

 Ehh, I would be using this to initialize druntime...

 You could just define _init, couldn't you?

 Yes, but there is only one _init, while the above can be used with
 multiple functions and thus wouldn't inadvertently cause important code
 to not run. If I don't have to, I'd rather not.

 Wait, why are you initializing druntime?

 Because druntime isn't set up to do it yet for c main calling d shared
 lib. You'd think it would need the same sort of functionality when it
 does implement it, though.

I don't know if it's automatically linked but here you go:

https://github.com/D-Programming-Language/druntime/blob/master/src/rt/dylib_fixes.c

-- 
/Jacob Carlborg

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

On 05/22/2013 11:18 PM, Jacob Carlborg wrote:
 On 2013-05-23 06:27, Ellery Newcomer wrote:

 I don't know if it's automatically linked but here you go:

 https://github.com/D-Programming-Language/druntime/blob/master/src/rt/dylib_fixes.c

posix.mak makes no reference to it

Jacob Carlborg <doob me.com> writes:

On 2013-05-24 02:02, Ellery Newcomer wrote:

 posix.mak makes no reference to it

Then I guess it's not used. Just compile it manually and link with it. I 
don't think that D has anything corresponding to 
__attribute__((constructor)). I also see a problem with adding such 
feature. It will be run before the runtime is initialized (that's how it 
works now). Then people will start using it and complain about there 
code failing in mysterious ways because the runtime isn't initialized.

-- 
/Jacob Carlborg

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

On 05/23/2013 11:39 PM, Jacob Carlborg wrote:
 On 2013-05-24 02:02, Ellery Newcomer wrote:

 posix.mak makes no reference to it

 Then I guess it's not used. Just compile it manually and link with it. I
 don't think that D has anything corresponding to
 __attribute__((constructor)). I also see a problem with adding such
 feature. It will be run before the runtime is initialized (that's how it
 works now). Then people will start using it and complain about there
 code failing in mysterious ways because the runtime isn't initialized.

so don't document it :)

Johannes Pfau <nospam example.com> writes:

Am Wed, 22 May 2013 21:27:00 -0700
schrieb Ellery Newcomer <ellery-newcomer utulsa.edu>:

 In the context of shared libraries, with gcc
 
 __attribute__((constructor))
 void myfunc() { .. }
 
 is used to make myfunc be called upon loading of the shared library
 (you can tell I know what I am talking about here) via some field in
 the ELF headers, apparently. Is there any way to get our trusty d
 compilers to do the equivalent?
 
 Sure, Ellery, we have this awesome feature called module
 constructors. Check em out.
 
 Ehh, I would be using this to initialize druntime...
 
 You could just define _init, couldn't you?
 
 Yes, but there is only one _init, while the above can be used with 
 multiple functions and thus wouldn't inadvertently cause important
 code to not run. If I don't have to, I'd rather not.
 
 Wait, why are you initializing druntime?
 
 Because druntime isn't set up to do it yet for c main calling d
 shared lib. You'd think it would need the same sort of functionality
 when it does implement it, though.

LDC has got #pragma(LDC_global_crt_[c/d]tor) for this, see
http://wiki.dlang.org/LDC-specific_language_changes#Pragmas

We will at some point implement something similar in gdc. I don't know
about dmd though.