• Johan Engelen (24/24) Mar 07 2016 (this is about DDMD internals, but the DMD-internals forum is
• Daniel Murphy (2/4) Mar 07 2016 That.
• Walter Bright (2/3) Mar 07 2016 Daniel is a man of few words :-)
• Johan Engelen (3/7) Mar 08 2016 :)
• Daniel Murphy (2/10) Mar 08 2016 If it still links. Vtbl emission can be tricky.

Johan Engelen <j j.nl> writes:

(this is about DDMD internals, but the DMD-internals forum is 
maillist only, so posting here. Pardon me please. [*] )

Currently some functions are defined (as opposed to declared) 
both in C++ and in D. For example, all of Visitor's virtual 
methods. The "double-defined" methods are all defined such that 
C++ should inline them (C++ spec), but it is causing trouble with 
MSVC (who does not inline as much in debug mode it seems, even 
when explicitly telling it to be spec compliant).
This is causing troubles when building LDC, using MSVC+LDC (using 
LDC as the D-compiler to build itself, instead of DMD who creates 
object files with a more lax linking attribute on all symbols). 
Symbols show up in D-object files and C++-object files and the 
MSVC linker does not want to link ldc2.exe. We can work around 
this... but I'd rather not increase the diff with upstream...

Regardless of LDC's troubles, do we really want methods to be 
double-defined? Is this intentional, or perhaps a remnant of 
semi-automated C++->D conversion? I doubt that the extra inlining 
possibilities are noticable (but I did not measure).

Shall I work on a PR that removes (some of) the double-defined 
guys from C++ source?
(read: would that have a chance of pulling without long debate)

Thanks,
   Johan


[*] Perhaps add a "DMD" section under "Ecosystem"?

Daniel Murphy <yebbliesnospam gmail.com> writes:

On 8/03/2016 7:12 AM, Johan Engelen wrote:
  or perhaps a remnant of
 semi-automated C++->D conversion?

That.

Walter Bright <newshound2 digitalmars.com> writes:

On 3/7/2016 2:19 PM, Daniel Murphy wrote:
 That.

Daniel is a man of few words :-)

Johan Engelen <j j.nl> writes:

On Monday, 7 March 2016 at 22:19:46 UTC, Daniel Murphy wrote:
 On 8/03/2016 7:12 AM, Johan Engelen wrote:
  or perhaps a remnant of
 semi-automated C++->D conversion?

 That.

:)
Out with it, then?

Daniel Murphy <yebbliesnospam gmail.com> writes:

On 8/03/2016 8:42 PM, Johan Engelen wrote:
 On Monday, 7 March 2016 at 22:19:46 UTC, Daniel Murphy wrote:
 On 8/03/2016 7:12 AM, Johan Engelen wrote:
  or perhaps a remnant of
 semi-automated C++->D conversion?

 That.

 :)
 Out with it, then?

If it still links.  Vtbl emission can be tricky.