using a proper event loop basis we no longer have to worry about most of
the intricacies of poll(), or platform-dependent replacements for it. we
may even be able to use the event loop and its promise system for all of
our scheduling in the future. we don't do any real async processing yet,
this is just preparation to separate the first such change from the huge
api design difference with the async framework we chose (kj from capnp):
kj::Promise, unlike std::future, doesn't return exceptions unmangled. it
instead wraps any non-kj exception into a kj exception, erasing all type
information and preserving mostly the what() string in the process. this
makes sense in the capnp rpc use case where unrestricted exception types
can't be transferred, and since it moves error handling styles closer to
a world we'd actually like there's no harm in doing it only here for now
Change-Id: I20f888de74d525fb2db36ca30ebba4bcfe9cc838
we're using boost::outcome rather than leaf or stl types because stl
types are not available everywhere and leaf does not provide its own
storage for error values, relying on thread-locals and the stack. if
we want to use promises we won't have a stack and would have to wrap
everything into leaf-specific allocating wrappers, so outcome it is.
Change-Id: I35111a1f9ed517e7f12a839e2162b1ba6a993f8f
When the multi-line log format is enabled, the progress bar usually occupies
multiple lines on the screen. When stopping the progress bar, only the last
line was wiped, leaving all others visible on the screen. Erase all lines
belonging to the progress bar to prevent these leftovers.
Asking the user for input is theoretically affected by a similar issue, but
this is not observed in practice since the only place where the user is asked
(whether configuration options coming from flakes should be accepted) does not
actually have multiple lines on the progress bar. However, there is no real
reason to not fix this either, so let's do it anyway.
Change-Id: Iaa5a701874fca32e6f06d85912835d86b8fa7a16
The AcceptFlakeConfig type used was missing its JSON serialisation definition,
so it was incorrectly serialised as an integer, ending up that way for example
in the nix.conf manual page. Declare a proper serialisation.
Change-Id: If8ec210f9d4dd42fe480c4e97d0a4920eb66a01e
The JSON serialisation should be declared in the header so that all translation
units can see it when needed, even though it seems that it has not been used
anywhere else so far. Unfortunately, this means we cannot use the
NLOHMANN_JSON_SERIALIZE_ENUM convenience macro, since it uses a slightly
different signature, but the code is not too bad either.
Change-Id: I6e2851b250e0b53114d2fecb8011ff1ea9379d0f
it just makes sense to have it too, rather than just the pass/fail
information we keep so far. once we turn goals into something more
promise-shaped it'll also help detangle the current data flow mess
Change-Id: I915cf04d177cad849ea7a5833215d795326f1946
it doesn't have a purpose except cache priming, which is largely
irrelevant by default (since another code path already runs this
exact query). our store implementations do not benefit that much
from this either, and the more bursty load may indeed harm them.
Change-Id: I1cc12f8c21cede42524317736d5987f1e43fc9c9
updating statistics *immediately* when any counter changes declutters
things somewhat and makes useful status reports less dependent on the
current worker main loop. using callbacks will make it easier to move
the worker loop into kj entirely, using only promises for scheduling.
Change-Id: I695dfa83111b1ec09b1a54cff268f3c1d7743ed6
there's no reason to go through the event loop in these cases. returning
ContinueImmediately here is just a very convoluted way of jumping to the
state we've just set after unwinding one frame of the stack, which never
matters in the cases changed here because there are no live RAII guards.
Change-Id: I7c00948c22e3caf35e934c1a14ffd2d40efc5547
this is not ideal, but it's better than having this stuck in the worker
loop itself. setting ex on all failing goals is not problematic because
only toplevel goals can ever be observable, all the others are ignored.
notably only derivation goals ever set `ex`, substitution goals do not.
Change-Id: I02e2164487b2955df053fef3c8e774d557aa638a
this doesn't serve a great purpose yet except to confine construction of
goals to the stack frame of Worker::run() and its child frames. we don't
need this yet (and the goal constructors remain fully visible), but in a
future change that fully removes the current worker loop we'll need some
way of knowing which goals are top-level goals without passing the goals
themselves around. once that's possible we can remove visible goals as a
concept and rely on build result futures and a scheduler built upon them
Change-Id: Ia73cdeffcfb9ba1ce9d69b702dc0bc637a4c4ce6
whether goal errors are reported via the `ex` member or just printed to
the log depends on whether the goal is a toplevel goal or a dependency.
if goals are aware of this themselves we can move error printing out of
the worker loop, and since a running worker can only be used by running
goals it's totally sufficient to keep a `Worker::running` flag for this
Change-Id: I6b5cbe6eccee1afa5fde80653c4b968554ddd16f
Apparently the fmt contraption has some extremely popular overloads, and
the boost stuff in there gets built approximately infinite times in
every compilation unit.
Change-Id: Ideba2db7d6bf8559e4d91974bab636f5ed106198
Fixes:
- Identifiers starting with _ are prohibited
- Some driveby header dependency cleaning which wound up with doing some
extra fixups.
- Fucking C style casts, man. C++ made these 1000% worse by letting you
also do memory corruption with them with references.
- Remove casts to Expr * where ExprBlackHole is an incomplete type by
introducing an explicitly-cast eBlackHoleAddr as Expr *.
- An incredibly illegal cast of the text bytes of the StorePath hash
into a size_t directly. You can't DO THAT.
Replaced with actually parsing the hash so we get 100% of the bits
being entropy, then memcpying the start of the hash. If this shows
up in a profile we should just make the hash parser faster with a
lookup table or something sensible like that.
- This horrendous bit of UB which I thankfully slapped a deprecation
warning on, built, and it didn't trigger anywhere so it was dead
code and I just deleted it. But holy crap you *cannot* do that.
inline void mkString(const Symbol & s)
{
mkString(((const std::string &) s).c_str());
}
- Some wrong lints. Lots of wrong macro lints, one wrong
suspicious-sizeof lint triggered by the template being instantiated
with only pointers, but the calculation being correct for both
pointers and not-pointers.
- Exceptions in destructors strike again. I tried to catch the
exceptions that might actually happen rather than all the exceptions
imaginable. We can let the runtime hard-kill it on other exceptions
imo.
Change-Id: I71761620846cba64d66ee7ca231b20c061e69710
this makes WorkResult copyable, and just all around easier to deal with.
in the future we'll need this to let Goal::work() return a promise for a
WorkResult (or even just a Finished) that can be awaited by other goals.
Change-Id: Ic5a1ce04c5a0f8e683bd00a2ed2b77a2e28989c1
this should be done where we're actually trying to build something, not
in the main worker loop that shouldn't have to be aware of such details
Change-Id: I07276740c0e2e5591a8ce4828a4bfc705396527e
This caused an absolute saga which I would not like anyone else to have
to experience. Let's put in a laser targeted error message that
diagnoses this exact problem.
Fixes: lix-project/lix#484
Change-Id: I2a79f04aeb4a1b67c10115e5e39501d958836298
This avoids C++'s standard library regexes, which aren't the same
across platforms, and have many other issues, like using stack
so much that they stack overflow when processing a lot of data.
To avoid backwards and forward compatibility issues, regexes are
processed using a function converting libstdc++ regexes into Boost
regexes, escaping characters that Boost needs to have escaped, and
rejecting features that Boost has and libstdc++ doesn't.
Related context:
- Original failed attempt to use `boost::regex` in CppNix, failed due to
boost icu dependency being large (disabling ICU is no longer necessary
because linking ICU requires using a different header file,
`boost/regex/icu.hpp`): https://github.com/NixOS/nix/pull/3826
- An attempt to use PCRE, rejected due to providing less backwards
compatibility with `std::regex` than `boost::regex`:
https://github.com/NixOS/nix/pull/7336
- Second attempt to use `boost::regex`, failed due to `}` regex failing
to compile (dealt with by writing a wrapper that parses a regular
expression and escapes `}` characters):
https://github.com/NixOS/nix/pull/7762Closes#34. Closes#476.
Change-Id: Ieb0eb9e270a93e4c7eed412ba4f9f96cb00a5fa4
nixpkgs delivered us the untimely gift of a meson 1.5 upgrade, which
*does* make our lives easier by allowing us to delete wrap generation
code, but it does so at the cost of renaming all rust crates in such a
way that the wrap logic cannot tolerate the new names on the old meson
version 😭.
It also means that support burden for this is going to be atrocious
until we either give in and vendor meson 1.5 or we make a CI target for
it. Neither seems appealing, though the latter is not super absurd for
ensuring we don't break nixpkgs unstable.
This commit causes meson 1.5 to ignore the .wrap files in subprojects/
entirely (since they have the wrong names lol) and instead use
Cargo.lock, so it now hard-depends on our workspace reshuffling
improvement.
It also deletes the hack that we were using to get the sources of Cargo
deps into meson by using a feature that went unnoticed when this code
was originally written: MESON_PACKAGE_CACHE_DIR:
8a202de6ec/mesonbuild/wrap/wrap.py (L490-L502)
Change-Id: I7a28f12fc2812c6ed7537b60bc3025c141a05874
This is purely to let Cargo's dependency resolver do stuff for us, we do
not actually intend to build this stuff with Cargo to begin with.
Change-Id: I4c08d55595c7c27b7096375022581e1e34308a87
There have been multiple setting types for paths that are supposed to be
canonicalised, depending on whether zero or one, one, or any number of paths is
to be specified. Naturally, they behaved in slightly different ways in the
code. Simplify things by unifying them and removing special behaviour (mainly
the "multiple paths type can coerce to boolean" thing).
Change-Id: I7c1ce95e9c8e1829a866fb37d679e167811e9705