What does 'inline' mean?

[Johannes Pfau]

Am Sat, 13 Jun 2020 01:33:34 -0700 schrieb Walter Bright:

> On 6/12/2020 9:08 PM, Manu wrote:
>>     If the di file is mentioned on the command line to the compiler
>> 
>> It's not, that's literally the point of a .di file.
> 
> No, it isn't. A .di file is more of a convention than a feature. It's a
> module and does not get special treatment by the compiler.
> 
>>     , yes (1)
>>     instance of it appears in the executable. Otherwise, (0) instances
>>     of it appear in the executable. There are never 2 or more instances
>>     in the executable.
>> 
>> Exactly. And this is not a useful design.
> 
> I hate to say it, but these sorts of replies are completely useless to
> resolving your issues. You omitted the *why*.
> 
> Why can't you put it on the command line?
> 


a.di:
void foo() {}

b.d:
import a;

c.d:
import a;
void main() {foo();}


dmd -c b.d
dmd -c c.d
dmd b.o c.o => undefined reference to `_D1a3fooFZv'

dmd -c a.di b.d -ofb.o
dmd -c a.di c.d -ofc.o
dmd b.o c.o => undefined reference to `_D1a3fooFZv'

mv a.di a.d
dmd -c a.d b.d -ofb.o
dmd -c a.d c.d -ofc.o
dmd b.o c.o => multiple definition of `_D1a12__ModuleInfoZ'

dmd -c a.d b.d -ofb.o -betterC
dmd -c a.d c.d -ofc.o -betterC
dmd b.o c.o => OK

BTW: If you do dmd -c a.di you get no object file output. So .di files 
are treated differently


I think it's interesting that DMD seems to emit some (all?) normal 
functions as weak. Not sure if LDC and GDC do the same thing. Would also 
be interesting to see how all this interacts with staic & shared 
libraries, though I'm optimistic that it just works.




So basically all that's missing for Manu's inline case would be to emit 
pragma(inlne) functions from non-root modules. Probably a 1-line change.
-- 
Johannes