On Saturday, 6 June 2015 at 19:44:15 UTC, Andrei Alexandrescu wrote:
> On 6/6/15 11:47 AM, Jacob Carlborg wrote:
[...]
>> I mean that rdmd should compile all files that has changed
>> including its dependencies, no more, no less. It should compile all
>> these files in one go.
>
> Yah, that's the traditional C-style module-at-a-time approach.

I think the traditional approach would be to compile modules separately, not "all [...] in one go".

> Somewhat paradoxically, for D it's faster to compile several files at once, even though not all were affected by the change.
>
> So in the package-at-a-time approach if at least one module in a package is affected by a change, the entire package gets rebuilt.

This may beat separately compiling modules that needs rebuilding. But it doesn't beat compiling all of them at once, does it?

My understanding of things:

Current behaviour: When any module changed, pass all source files to one dmd invocation.

The makefile approach: Separately recompile every module that needs rebuilding; then link the new object files with the cached ones.

Your proposal, variant 1: For every module that needs rebuilding, separately recompile its whole package; then link the new object files with the cached ones of other packages.

Variant 2: For every module that needs rebuilding, determine what package it belongs to; then pass the source files of those packages and the cached object files of other packages to one dmd invocation.

The seemingly obvious thing to do: Pass the source files that need rebuilding and the object files of other modules to one dmd invocation.

On 2015-06-06 22:27, anonymous wrote:

> The seemingly obvious thing to do: Pass the source files that need
> rebuilding and the object files of other modules to one dmd invocation.

That's what I've been thinking all along and trying to say.

-- 
/Jacob Carlborg

On Saturday, 6 June 2015 at 21:10:22 UTC, Jacob Carlborg wrote:
> On 2015-06-06 22:27, anonymous wrote:
>
>> The seemingly obvious thing to do: Pass the source files that need
>> rebuilding and the object files of other modules to one dmd invocation.
>
> That's what I've been thinking all along and trying to say.

I don't think I understand. Where would these object files come from unless you're doing per-module compilation, C-style?

What I've already implemented is variant 1 mentioned before.

Atila

On 6/6/15 1:27 PM, anonymous wrote:
> The seemingly obvious thing to do: Pass the source files that need
> rebuilding and the object files of other modules to one dmd invocation.

Doesn't work because no separate object file per source is being produced. -- Andrei

On Saturday, 6 June 2015 at 21:24:05 UTC, Atila Neves wrote:
> I don't think I understand. Where would these object files come from unless you're doing per-module compilation, C-style?

Huh, I somehow assumed dmd would spit out multiple object files when given multiple source files. Since that's not so, variant 2 and the "seemingly obvious thing" are seemingly not possible.

But if dmd could be made to produce multiple object files ...
(I have no idea if that's doable.)

On 6/6/15 2:42 PM, anonymous wrote:
> But if dmd could be made to produce multiple object files ...
> (I have no idea if that's doable.)

Not advantageously. -- Andrei

On 2015-06-06 23:24, Atila Neves wrote:

> I don't think I understand. Where would these object files come from
> unless you're doing per-module compilation, C-style?
>
> What I've already implemented is variant 1 mentioned before.

If you compile multiple files with DMD without linking it will produce multiple object files:

$ ls
bar.d foo.d
$ dmd -c bar.d foo.d
$ ls
bar.d bar.o foo.d foo.o

-- 
/Jacob Carlborg

On 2015-06-06 23:41, Andrei Alexandrescu wrote:

> Doesn't work because no separate object file per source is being
> produced. -- Andrei

They're produced if you don't link.

-- 
/Jacob Carlborg

On Saturday, 6 June 2015 at 20:27:12 UTC, anonymous wrote:
> The seemingly obvious thing to do: Pass the source files that need rebuilding and the object files of other modules to one dmd invocation.

I implemented this. Preliminary pull request:
https://github.com/D-Programming-Language/tools/pull/170