Commit graph

6 commits

Author SHA1 Message Date
Eelco Dolstra
0a10854f85 Misc changes from the flakes branch 2020-03-24 14:34:47 +01:00
Eelco Dolstra
bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00
Eelco Dolstra
e07ec8d27e
Support allowSubstitutes attribute in structured attribute derivations
Hopefully fixes #3081 (didn't test).
2019-09-03 16:03:49 +02:00
Eelco Dolstra
ef52ccf035
experimental/optional -> optional 2019-03-14 14:10:52 +01:00
Eelco Dolstra
1e7b8deea7
Check requiredSystemFeatures for local builds
For example, this prevents a "kvm" build on machines that don't have
KVM.

Fixes #2012.
2018-09-28 16:10:27 +02:00
Eelco Dolstra
7ae7a38c9a
Move structured attrs handling into a separate class
This is primarily because Derivation::{can,will}BuildLocally() depends
on attributes like preferLocalBuild and requiredSystemFeatures, but it
can't handle them properly because it doesn't have access to the
structured attributes.
2018-09-28 14:32:46 +02:00