We choose to throw an error in the invalid-input space where we *can*
produce a valid (but wrong) result to allow ourselves to, mirroring
CppNix, change the semantics to not corrupt it at all in the future,
while having a middle state where it is an error.
This is a largely-rewritten version of
https://github.com/NixOS/nix/pull/13013.
Co-authored-by: rootile <lix@rootile.de>
Fixes: https://github.com/NixOS/nix/issues/12899
Upstream-PR: https://github.com/NixOS/nix/pull/13013
Change-Id: I6a6a6964cdd1a88714952e80c660d1fa57d1f2d8
While it doesn't make sense to have `foo..bar`, the attribute-path
`foo."".bar` is valid and shouldn't throw.
Change-Id: Ifcddaad6233c6ba8f17cb5c953c2101d276dfeb6
In messages printed by the evaluator, we use showType(.) to say things
like "expected X, got Y" where X, Y can be string, string with context,
etc.
After changes in the Lix data model (pointer tagging and friends), paths
got squished inside a internal string type.
We missed updating `showType` to take this fact into account which
caused an unfortunate:
`error: expected a string but found a string with context:
/nix/store/wjf8rdpp63rhyasbzc7zfms1agf7pwyd-source`
while using a path on `builtins.getContext`
A test is added.
Change-Id: Ifb0129ead2ea1973fc17dc0133f8a694995536b1
Signed-off-by: Raito Bezarius <raito@lix.systems>
Instead of taking in a final argument `Value &` out parameter which it
writes to, it now returns its result
Change-Id: Iab6bc3a3ac6a4b17c6d31115a766a6ea6a6a6964
The pseudo-constructor `Value::mkFloat` would previously be called on an
default-constructed (under-initialized) `Value` to create a properly
initialized `Value` that represents a float. This change removes mkFloat
and constructs float `Value`s directly.
Change-Id: I48ae3a836842ce5e5eda6323404ba7576a6a6964
The pseudo-constructor `Value::mkPath` would previously be called on an
default-constructed (under-initialized) `Value` to create a properly
initialized `Value` that represents a path. This change
removes mkPath and constructs path `Value`s directly.
Change-Id: I9021de1ff59490828f9fec6866e083996a6a6964
The pseudo-constructor `Value::mkAttrs` would previously be called on an
default-constructed (under-initialized) `Value` to create a properly
initialized `Value` that represents an attribute set. This change
removes mkAttrs and constructs attr `Value`s directly.
Change-Id: I11cd801eefecd454a7a5b6229d6770d06a6a6964
That struct has been annoying me since I've encountered it. There is no
reason for having to track all these symbols out of band in the state.
Change-Id: I5c2c0d8174af0a51f9b456cc3651d8203a406d09
Added builtins.warn` which takes two arguments: a message that is
displayed as a warning during evaluation which must be a string and a
value that is returned from the expression.
The next commits add new settings to control the behavior of the new
builtin: `debugger-on-warn` allows the user to start the debugger and
`abort-on-warn` aborts evaluation with an error.
Unlike upstream, I chose not to mark evaluation warnings from
`builtins.warn` as distinct from other warnings because that breaks the
commonly expected logging format `level: message`.
Co-authored-by: Qyriad <qyriad@qyriad.me>
Upstream-PR: https://github.com/NixOS/nix/pull/10592
Fixes: https://git.lix.systems/lix-project/lix/issues/579
Change-Id: I8658c88e5c27952b65e8b9f5525a572e0680cc1f
currently all loggers can always accept messages and never suggest
flushing buffers. in the future this may change, and at that point
we're already fully set up for it. local loggers should never keep
asynchronous (i.e. network-backed) buffers, disk buffers are fine.
networked loggers will require buffers and periodic flushes later.
Change-Id: Ide2114f5bc17f4a1d289c92ed4f9381a1d59dacf
thunk values are shareable, and we can represent invalid/uninitialized
values with a special bit pattern that makes no sense otherwise. there
is no need to keep allocating values on the heap, instead we can treat
values like reference-counted smart pointers to heap objects, which in
turn lets us save a lot of allocations and, ultimately, gc heap space.
compared to our baseline (main of 2025-09-27) we save 15%+ memory on a
system rebuild and 17% on nix search. eval time regresses by ~3% for a
system rebuild, while nix search is 7% faster. further optimization is
probably possible (but for now this will just have to be good enough).
Change-Id: Ib6c47acdbe2fac4f76a83c2269f16f30ef66b2e1
with thunk state being shareable we no longer need to worry about value
uniqueness, only about value lifetime. this means we can liberally drop
indirections and allocations, passing references instead of pointers or
using stack memory instead of gc-managed memory for some intermediates.
Change-Id: I2d48a6fd57a376d544bd9bd2d05e5420611986d1
same as for null: we have few of them, they're statically allocated,
and they're not the largest contributor to the value population. not
storing them in Value itself frees up resources we *will* use later.
Change-Id: I521f9f243f48f56a78f7bffdf1dc1f0bc40a5c2d
using the same nodes as tApp is possible, and thanks to multi-arg app
nodes it can even be a bit faster than the linked lists used to date.
Change-Id: Idccb7c0b54c808e62da85d1c42ee09e6e92c4f7b
these behave like the old chains of app nodes, but they can store more
than one argument per node. for tApp values themselves this is not all
that useful, but if we could share tApp and tPrimOpApp backing storage
we could avoid creating and traversing the linked lists of values that
are currently needed to represent partially applied builtin functions.
Change-Id: I5a2a02d9733e1e0be5443459e2998d62fd3b9a5b
memory overhead is minimal and performance impact not measurable. once
we've done something like this for all value types that don't fit in a
single machine word we can cut a word from Value, offsetting the cost.
Change-Id: I9813bacd7e851957ad3426aed8f74033179a4212
on its own this is not very useful, but having accessors for every value
kind is a prerequisite for doing smart things with Value than the union.
the net effect for now is only to add a few parentheses across the tree.
Change-Id: I88688ac09eb08495dad1eb221034ca540f094950
Prior to this change, references or pointers could be mutated. In
practice, we do not require this capability in the codebase except in
zipAttrsWith.
This cleans up all easy sites in preparation to have a smarter
representation of attribute sets albeit one that requires constant
references.
Change-Id: I2be20cce040a9228bde9e5f7b42c0499fba9550b
Signed-off-by: Raito Bezarius <raito@lix.systems>
Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>
Concept: what if you could, in your fancy terminal, in the year of our
lord 2025, just click on the attrs you're looking at to go to where
they're defined. Currently we only expose this info as
builtins.unsafeGetAttrPos, which is inconvenient as it's not
discoverable to users.
By putting it in this more visible yet invisible spot, it's more likely
to be more useful to more people.
In the current state, this is not the most useful ever due to stuff like
https://github.com/neovim/neovim/discussions/35097. However, it can be
expanded by perhaps adding something like the url format setting ripgrep
has.
Change-Id: I3947f97d5c2056d59099af468d7b855486438227
Avoids incorrect behavior with large integers in `elemAt`, `substring`,
`genList`, etc, which results into crashing the Lix interpreter.
At the same time, unit tests were added for these edge cases with 2^32
as an argument of these primops.
Port of https://github.com/NixOS/nix/pull/13309.
Prior art in https://github.com/NixOS/nix/pull/7222 (forgotten by the original project…).
Change-Id: I1c43ed64f26bcb60e51869e11a74e5de2b7db53a
Co-authored-by: Raito Bezarius <raito@lix.systems>
Signed-off-by: Raito Bezarius <raito@lix.systems>
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
