Dependency management in D

[Scott Wilson via Digitalmars-d]

On Friday, 19 September 2014 at 05:17:45 UTC, Walter Bright wrote:
> On 9/18/2014 9:48 AM, Scott Wilson wrote:
>> Im running some tests with D. Was wondering whats the 
>> dependency
>> story. Cant find any info online, searched for dlang dependency
>> management and dlang dependency. Found bunch o dub stuff but 
>> not
>> the nitty gritty.
>>
>> Unit of compilation is one D file but I saw if I pass several D
>> files to the compiler only one .o file is generated. Whats the
>> story there.
>
> The idea is to essentially "pre-link" the object files that 
> would have been generated if the files were compiled 
> individually into one object file. This is faster and more 
> convenient.
>
> It also means that semantic analysis is done only once for each 
> file, and the imports, rather than doing it over and over as is 
> done with separate compilation.
>
>
>> Plus if I change a non template function in one module then
>> theres no way to tell make no rebuild of modules importing it.
>> The dmd -deps call seems to generate all recursively. In
>> gcc/makedepend if one function changes only relinking is needed
>> or nothing if dynamic loading.
>
> Dependency management is the same as in C++, if you are willing 
> to use .di files to represent 'headers' of corresponding .d 
> files.
>
>
>> Overall as far as I understand compiler is fast but dependency
>> mgmt is coarse. Also whats the deal with cyclic dependencies. I
>> saw discussion that its not possible but wrote a few test 
>> modules
>> and it works fine.
>
> If two modules import each other, then if one changes, both 
> should get recompiled.

Im worrying about recursive dependencie. If a.d imports b.d and
b.d imports c.d then I change c.d. Is a.d compiled again?
Sometimes it should sometimes it shouldnt.

Scott