On Friday, 21 September 2018 at 06:30:40 UTC, Walter Bright wrote:
On 9/20/2018 10:11 PM, mate wrote:
Note that the build can be done at compile time because the
metaprogramming capabilities of the language are not limited
in terms of system calls.
Back in the naive olden days, Microsoft released ActiveX, where
a web page could load executable objects (!) from the internet
and run them in the browser.
It quickly became apparent that this was a disaster, as lots of
people on the internet aren't to be trusted.
CTFE on D doesn't allow making any system calls. This is on
purpose.
The usual argument against this is that source code distributions
already usually include some sort of build or installation script
(be it in the form of "configure", or a makefile, or a Visual
Studio project), which can already execute arbitrary commands.
The problem with putting it in the compiler is that it
invalidates many contracts (and, thus, use cases) about what
invoking the compiler can do. This means you can't bisect or
reduce (as with Dustmite) the source code reliably. Reproducible
builds are out too, as the produced object file is no longer
purely a function of the source code and compiler version.
