Study: build times for D programs

[Walter Bright]

On 7/25/2012 1:53 PM, Rainer Schuetze wrote:
> The "edit-compile-debug loop" is a use case where the D module system does not
> shine so well. Compare build times when only editing a single source file:
> With the help of incremental linking, building a large C++ project only takes
> seconds.
> In contrast, the D project usually recompiles everything from scratch with every
> little change.


I suspect that's one of two possibilities:

1. everything is passed on one command line to dmd. This, of course, requires 
dmd to recompile everything.

2. modules are not separated into .d and .di files. Hence every module that 
imports a .d file has to, at least, parse and semantically analyze the whole 
thing, although it won't optimize or generate code for it.


As for incremental linking, optlink has always been faster at doing a full link 
than the Microsoft linker does for an incremental link.