we no longer need placeholders to represent all derivation output paths
as string context, and thus will not need experimental features either.
Change-Id: I9e86ce86810e976cf8397b2c2f473af11390874c
we no longer have any experimental features depending on ca derivations,
so we can start removing them. since ca derivations are very invasive we
will need a while to remove all of the explicitly experimental code, and
even then we will not have removed *all* code related to ca derivations.
especially in the derivation goals there is a lot of code that is not as
easy to disentangle from experimental features as some would have hoped.
Change-Id: Ia456aadc6164613ded343f571318494d9310a549
only dynamic derivations could produce a non-opaque drvPath. since
dynamic derivations are no longer supported we can have drvPath be
opaque at all times, simplifying downstream code significantly and
making quite a few methods unnecessary. discardOutputPath was only
called on drvPath members anyway and thus reduces to a copy, other
operations at the very least are no longer recursive. some vestige
of dynamic derivations remains in DerivedPathMap though (for now).
Change-Id: Ifb4ad53a3c67800be5a62540068c8279d4ae0046
string context doesn't need any tests because it's never persisted or
shown to the user. getting rid of recursive string context means that
the context string parsers can be a lot simpler from here on forward.
Change-Id: I58443679ad76c0f28ea5f4eb8bfb3874f270e764
with impure derivations gone we move on to dynamic derivations. this too
is not done in a single commit because dynamic derivations are invasive,
modifying semantics of all references to derivation output paths and all
derivation dependency calculations. removing dynamic derivations cleanly
is made significantly harder by the multiple did-you-mean-sum types, aka
"wrappers for std::variant", holding all derivation outpath information.
Change-Id: Ice7a7700c7b54c6a6061d4beb322b4175923d27a
we don't remove the entire feature in one go to make review easier.
impure derivations are rather unintrusive on their own, at least if
we compare them to dynamic or ca derivations in general, so we will
be done with this soon. as it stands impure derivations cannot work
without ca derivations, and those we *really* want to leave behind.
Change-Id: I4f01d8d758b2c85dcd6c3078304b5ee1b52f65b0
Now that we can correctly point to all expressions, we can remove
redundant intermediate traces to reduce clutter.
Co-authored-by: eldritch horrors <pennae@lix.systems>
Co-authored-by: Raito Bezarius <raito@lix.systems>
Change-Id: I3e9d7c1c7a6599a8e68302448bbb961d051002b7
otherwise lix may crash when e.g. nix search receives invalid regex.
we now also give better error messages for regex errors during eval.
fixes#803
Change-Id: Icc7c578ff488ba520efac5d898572ccf4486e9a8
There is a pull request [1] addressing these upstream--it doesn't appear
likely to be merged anytime soon though... this is a no-op til we enable
-Wdeprecated-declarations, but helps in the direction of #744
[1]: https://github.com/emil-e/rapidcheck/pull/325
Change-Id: I27e2c7d81df152de8674696f2a56d5f21c414ce3
This seems to be a copypasta mistake that slipped through when writing the
initial tests. Changes the ValuePrintingTests::tPath to actually test a path
value instead of a string.
Change-Id: I20fe72635a0b1a6a0d72f674a4619da0de9f3d44
technically it doesn't *have* to be NeverAsync, but not marking it as
such unconditionally requires templating DebugState over asyncness of
its callback (which then requires templating EvalState, which, *NO*.)
Change-Id: I4980d45b541c2e40328beac139b18c6c1ba0957c
This is kind of a painful change, because a lot of code grew around the
bad abstraction, but the goal here is to abstract formals in a way that
allows adding other means of pattern matching / argument destructuring
in the future.
Change-Id: If4e681a4be3d1f42ceea81a8e07297f0d08acc80
After gathering more community feedback, more non-trivial use cases for
overriding `__findFile` emerged. Unlike the use case of Tvix mentioned
in #599, these can't easily be worked around by overriding `nixPath`
instead.
This is the second fixup/partial revert for
81d5f0a7d9.
See also #599.
Change-Id: I7ca75e1a2b196c0da341969c61f4c168b5f657f9
It being overridable was an intended feature with good use cases, and
should not have been removed. However, this feature is generally in a
bad state and needs revisiting in the future.
Fixup for 81d5f0a7d9Fixes#599
Change-Id: I2d93e012caa65aa795bce3a71d8e56d7052ef9df
The `show` functionality needs to be removed because it is deeply
flawed, and given that we already print position information in the
error message (which probably wasn't always the case in the past) the
assertion printing is redundant anyways.
Change-Id: I1f5e05ab73aaa0ec92994c2211463260fd374898
this is not necessary in any way, but it will make the following changes
smaller and easier to review. the aliases could also be added piecemeal,
but doing it here lets us lean heavily on our compilers for correctness.
(teacher notes: here the author foreshadows the shape of things to come.
not all names change, and only the names unchanged are those which will,
over time, become ever more unrecognizable. note especially nix/main.cc,
where `state` is not only cloned, but itself changes pointerness. it can
be seen as a nod to the trans community, but more realistically it is no
more than foreshadowing the future where `state` is only seen by proxy.)
Change-Id: I7732025e58df089b7f8e564fc63960cd91729d09
this will let us pass the capability to create debuggable eval errors
without having to pass an entire EvalState. we could pass symbols and
debug states around just as easily, but if we add new capabilities to
our debugger we might have to change many more places than with this.
Change-Id: I2f8893012e5d98a986ef1fc888234c2dd8d5e096
It was never intended to be a feature to be used, and moreover it is
inconsistent: One cannot override `+`, and overriding `__lessThan` won't
affect the builtins which do comparisons.
Change-Id: Iaba54a05aa4c2eb37cdb3dc0d731fcee5a86deba
this belongs to lazy trees, which we neither have nor intend to have.
we will keep SourcePath as that may come in handy at some later date.
Change-Id: I44b8f1dd6c435d7486c393fabdcd272766b2b56b
not all of these are even used by eval itself. notably sWith wasn't used
at all, sEpsilon was only used by the eval cache one layer up, and other
attributes are used in places even further away from eval itself. we can
keep this commingling for now, but eventually we should clean it up too.
Change-Id: I5684ac614361bf008e04472130c6c02082b4c2d7
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
They are like experimental features, but opt-in instead of opt-out. They
will allow us to gracefully remove language features. See #437
Change-Id: I9ca04cc48e6926750c4d622c2b229b25cc142c42
The |> operator is a reverse function operator with low binding strength
to replace lib.pipe. Implements RFC 148, see the RFC text for more
details. Closes#438.
Change-Id: I21df66e8014e0d4dd9753dd038560a2b0b7fd805
Currently, the parser relies on the global experimental feature flags.
In order to properly test conditional language features, we instead need
to pass it around in the parser::State.
This means that the parser cannot cache the result of isEnabled anymore,
which wouldn't necessarily hurt performance if the function didn't
perform a linear search on the list of enabled features on every single
call. While we could simply evaluate once at the start of parsing and
cache the result in the parser state, the more sustainable solution
would be to fix `isEnabled` such that all callers may profit from the
performance improvement.
Change-Id: Ic9b9c5d882b6270e1114988b63e6064d36c25cf2
When the configured maximum depth has been reached, attribute sets and lists
are printed with ellipsis to indicate the elision of nested items. Previously,
this happened even in case the structure being printed is empty, so that such
items do not in fact exist. This is confusing, so stop doing it.
Change-Id: I0016970dad3e42625e085dc896e6f476b21226c9
The repeated value detection logic exists so that the occurrence of large
common substructures does not fill up the screen or the computer's memory.
However, empty attribute sets and derivations (when their detection is enabled)
are always cheap to print, and in practice I have observed them to make up a
significant majority of the cases where I was annoyed by the repeated value
detection kicking in. Furthermore, `nix-instantiate --eval` already disables
this logic for empty attribute sets, and empty lists are already exempted
everywhere. For these reasons, always print empty attribute sets and
derivations as what they are.
Change-Id: I5dac8e7739f9d726b76fd0521ec46f38af94463f
with the prepatory work done this mostly means turning plain pointers
into unique_ptrs, with all the associated churn that necessitates. we
might want to change some of these to box_ptrs at some point as well,
but that would be a semantic change that isn't fully appropriate yet.
Change-Id: I0c238c118617420650432f4ed45569baa3e3f413
almost all places where Exprs are passed as pointers expect the pointers
to be non-null. pass them as references to encode this constraint in the
type system as well (and also communicate that Exprs must not be freed).
Change-Id: Ia98f166fec3c23151f906e13acb4a0954a5980a2
We're not using it anymore. Any leftover bugs in the Meson buildsystem
are now just bugs.
Closes#249.
Change-Id: I0465a0c37ae819f94d40e7829f5bff046aa63d73
we now keep not a table of all positions, but a table of all origins and
their sizes. position indices are now direct pointers into the virtual
concatenation of all parsed contents. this slightly reduces memory usage
and time spent in the parser, at the cost of not being able to report
positions if the total input size exceeds 4GiB. this limit is not unique
to nix though, rustc and clang also limit their input to 4GiB (although
at least clang refuses to process inputs that are larger, we will not).
this new 4GiB limit probably will not cause any problems for quite a
while, all of nixpkgs together is less than 100MiB in size and already
needs over 700MiB of memory and multiple seconds just to parse. 4GiB
worth of input will easily take multiple minutes and over 30GiB of
memory without even evaluating anything. if problems *do* arise we can
probably recover the old table-based system by adding some tracking to
Pos::Origin (or increasing the size of PosIdx outright), but for time
being this looks like more complexity than it's worth.
since we now need to read the entire input again to determine the
line/column of a position we'll make unsafeGetAttrPos slightly lazy:
mostly the set it returns is only used to determine the file of origin
of an attribute, not its exact location. the thunks do not add
measurable runtime overhead.
notably this change is necessary to allow changing the parser since
apparently nothing supports nix's very idiosyncratic line ending choice
of "anything goes", making it very hard to calculate line/column
positions in the parser (while byte offsets are very easy).
(cherry picked from commit 5d9fdab3de0ee17c71369ad05806b9ea06dfceda)
Change-Id: Ie0b2430cb120c09097afa8c0101884d94f4bbf34
This builtin is only going to cause us problems because we are not Nix,
so let's just falsify being in the 2.18 series, since that is the
closest target that has any meaning.
In future we might want to have a better feature detection mechanism,
for when we actually add stuff to some builtin's attr set argument. But
builtins.nixVersion is just going to be hopelessly broken and it should
be stubbed out.
Fixes https://git.lix.systems/lix-project/lix/issues/144
Change-Id: Id7390b32a29c6147f2977737d81846320de5d67e
Pretty-print values in the REPL by printing each item in a list or
attrset on a separate line. When possible, single-item lists and
attrsets are printed on one line, as long as they don't contain a nested
list, attrset, or thunk.
Before:
```
{ attrs = { a = { b = { c = { }; }; }; }; list = [ 1 ]; list' = [ 1 2 3 ]; }
```
After:
```
{
attrs = {
a = {
b = {
c = { };
};
};
};
list = [ 1 ];
list' = [
1
2
3
];
}
```
(cherry picked from commit c0a15fb7d03dfb8f53bc6726c414bc88aa362592)
Change-Id: Ia2b41849165a5ddb63f7a8c272a2476b3e4292df
While preparing PRs like #9753, I've had to change error messages in
dozens of code paths. It would be nice if instead of
EvalError("expected 'boolean' but found '%1%'", showType(v))
we could write
TypeError(v, "boolean")
or similar. Then, changing the error message could be a mechanical
refactor with the compiler pointing out places the constructor needs to
be changed, rather than the error-prone process of grepping through the
codebase. Structured errors would also help prevent the "same" error
from having multiple slightly different messages, and could be a first
step towards error codes / an error index.
This PR reworks the exception infrastructure in `libexpr` to
support exception types with different constructor signatures than
`BaseError`. Actually refactoring the exceptions to use structured data
will come in a future PR (this one is big enough already, as it has to
touch every exception in `libexpr`).
The core design is in `eval-error.hh`. Generally, errors like this:
state.error("'%s' is not a string", getAttrPathStr())
.debugThrow<TypeError>()
are transformed like this:
state.error<TypeError>("'%s' is not a string", getAttrPathStr())
.debugThrow()
The type annotation has moved from `ErrorBuilder::debugThrow` to
`EvalState::error`.
(cherry picked from commit c6a89c1a1659b31694c0fbcd21d78a6dd521c732)
Change-Id: Iced91ba4e00ca9e801518071fb43798936cbd05a
eldritch horrors