Re Build tools for D [ was Re: Prototype buildsystem "Drake"]

[Jacob Carlborg]

On 2011-07-18 19:37, James Fisher wrote:
> When writing Haskell and compiling with GHC, the compiler automatically
> finds the module dependencies and compiles them in the correct order.
>   If I touch a few modules and recompile, GHC will only recompile the
> touched modules as appropriate, then re-link.  In other words, GHC is
> the build tool as well as the compiler.  The advantages of this approach
> over having a separate build tool are:
>
> - the compiler already knows how to parse module files, so it's in the
> perfect position to know what the dependencies are.  We don't have some
> hacky extra tool sniffing out lines that look like "import X;".  This
> alone seems error-prone, but more importantly, D modules can have
> arbitrary compile-time logic executed before importing something, so the
> build tool essentially either has to give up or reimplement the compiler
> to cover all cases.  (This is the primary reason I advocate this
> approach -- I don't see how a generic build tool can automatically
> detect dependencies without the participation of a D compiler.)
> - the steps to compile a one-file program are exactly the same as
> compiling a complex multi-module program: "ghc Main".  If I split out
> one file into several, I don't have to immediately switch to using
> Make/waf/etc; it will Just Work.  There's one less tool to remember, and
> once you've got your D compiler, you're all set.

With DMD you can use the -deps flag to get all the dependencies of all 
specified files. No reason to try to parse import statements.

Can GHC compiler other types than executables, i.e. libraries?

-- 
/Jacob Carlborg