tooling quality and some random rant

[Vladimir Panteleev]

On Sun, 13 Feb 2011 08:00:57 +0200, golgeliyele <usuldan at gmail.com> wrote:

> The error reporting has issues as well. I noticed that the compiler  
> leaks low level errors to the user. If you forget to add a main to your
> app or misspell it, you get errors like:
> ====
> Undefined symbols:
>   "__Dmain", referenced from:
>       _D2rt6dmain24mainUiPPaZi7runMainMFZv in  
> libphobos2.a(dmain2_513_1a5.o)
> ====
> I mean, wow, this should really be handled better.

This has been brought up before. Walter insists it's not a problem.

> Another annoyance, for me anyway, is that the DMD compiler outputs the  
> .o files without the package directory hierarchy. I like to
> organize my code as 'src/my/package/module.d'. And I want to set my  
> output directory to 'lib' and get 'lib/my/package/module.o'.
> But DMD generates 'lib/module.o'. I setup my project to build each .d  
> file into a .o file as a separate step. I don't even know if this is
> the desired setup. But that seems to be the way to make it incremental.  
> I couldn't find any definitive information on this in the DMD
> compiler web page. It says:
> "dmd can build an executable much faster if as many of the source files  
> as possible are put on the command line.

Correctly-working incremental builds are not possible with DMD. This is an  
old problem that isn't easy to fix, due to the way the compiler was  
designed and written.

> Another advantage to putting multiple source files on the same  
> invocation of dmd is that dmd will be able to do some level of cross-
> module optimizations, such as function inlining across modules."

I've been told that DMD will actually do cross-module optimizations even  
if you don't specify the other modules on its command-line. Unless you use  
.di files, the point is that unlike C++, the compiler has access to the  
full source code of all included modules, not just a header file, so it  
can do inlining and whatnot.

-- 
Best regards,
  Vladimir                            mailto:vladimir at thecybershadow.net