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2024-10-01Split ignoreException to avoid suppressing CTRL-CRobert Hensing
This splits `ignoreException` into `ignoreExceptionExceptInterrupt` (which ignores all exceptions except `Interrupt`, which indicates a SIGINT/CTRL-C) and `ignoreExceptionInDestructor` (which ignores all exceptions, so that destructors do not throw exceptions). This prevents many cases where Nix ignores CTRL-C entirely. See: https://github.com/NixOS/nix/issues/7245 Upstream-PR: https://github.com/NixOS/nix/pull/11618 Change-Id: Ie7d2467eedbe840d1b9fa2e88a4e88e4ab26a87b
2024-08-08refactor: make HashType and Base enum classes for type safetyJade Lovelace
Change-Id: I9fbd55a9d50464a56fe11cb42a06a206914150d8
2024-07-13language: cleanly ban integer overflowsJade Lovelace
This also bans various sneaking of negative numbers from the language into unsuspecting builtins as was exposed while auditing the consequences of changing the Nix language integer type to a newtype. It's unlikely that this change comprehensively ensures correctness when passing integers out of the Nix language and we should probably add a checked-narrowing function or something similar, but that's out of scope for the immediate change. During the development of this I found a few fun facts about the language: - You could overflow integers by converting from unsigned JSON values. - You could overflow unsigned integers by converting negative numbers into them when going into Nix config, into fetchTree, and into flake inputs. The flake inputs and Nix config cannot actually be tested properly since they both ban thunks, however, we put in checks anyway because it's possible these could somehow be used to do such shenanigans some other way. Note that Lix has banned Nix language integer overflows since the very first public beta, but threw a SIGILL about them because we run with -fsanitize=signed-overflow -fsanitize-undefined-trap-on-error in production builds. Since the Nix language uses signed integers, overflow was simply undefined behaviour, and since we defined that to trap, it did. Trapping on it was a bad UX, but we didn't even entirely notice that we had done this at all until it was reported as a bug a couple of months later (which is, to be fair, that flag working as intended), and it's got enough production time that, aside from code that is IMHO buggy (and which is, in any case, not in nixpkgs) such as https://git.lix.systems/lix-project/lix/issues/445, we don't think anyone doing anything reasonable actually depends on wrapping overflow. Even for weird use cases such as doing funny bit crimes, it doesn't make sense IMO to have wrapping behaviour, since two's complement arithmetic overflow behaviour is so *aggressively* not what you want for *any* kind of mathematics/algorithms. The Nix language exists for package management, a domain where bit crimes are already only dubiously in scope to begin with, and it makes a lot more sense for that domain for the integers to never lose precision, either by throwing errors if they would, or by being arbitrary-precision. This change will be ported to CppNix as well, to maintain language consistency. Fixes: https://git.lix.systems/lix-project/lix/issues/423 Change-Id: I51f253840c4af2ea5422b8a420aa5fafbf8fae75
2024-05-29util.{hh,cc}: Split out users.{hh,cc}Tom Hubrecht
Change-Id: I1bd92479a2cb7e5c2c2e1541b80474adb05ea0df
2024-04-10don't boost::to_few_args when an eval cached string type errorsQyriad
Change-Id: Id3cb762622e156ceaf9d5bb95c2c704ffe474d0e
2024-04-06always re-eval cached failuresQyriad
This is terrible UX, and frankly an eval failure should be a cache invalidation anyway. This removes the CachedEvalError type entirely. Fixes #223. Change-Id: I91f8003eabd0ea45003024e96d1de3c7ae8e49d8
2024-03-09libexpr: Support structured error classeseldritch horrors
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
2023-08-18Fixing #7479John Ericson
Types converted: - `NixStringContextElem` - `OutputsSpec` - `ExtendedOutputsSpec` - `DerivationOutput` - `DerivationType` Existing ones mostly conforming the pattern cleaned up: - `ContentAddressMethod` - `ContentAddressWithReferences` The `DerivationGoal::derivationType` field had a bogus initialization, now caught, so I made it `std::optional`. I think #8829 can make it non-optional again because it will ensure we always have the derivation when we construct a `DerivationGoal`. See that issue (#7479) for details on the general goal. `git grep 'Raw::Raw'` indicates the two types I didn't yet convert `DerivedPath` and `BuiltPath` (and their `Single` variants) . This is because @roberth and I (can't find issue right now...) plan on reworking them somewhat, so I didn't want to churn them more just yet. Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
2023-08-10Make the Derived Path family of types inductive for dynamic derivationsJohn Ericson
We want to be able to write down `foo.drv^bar.drv^baz`: `foo.drv^bar.drv` is the dynamic derivation (since it is itself a derivation output, `bar.drv` from `foo.drv`). To that end, we create `Single{Derivation,BuiltPath}` types, that are very similar except instead of having multiple outputs (in a set or map), they have a single one. This is for everything to the left of the rightmost `^`. `NixStringContextElem` has an analogous change, and now can reuse `SingleDerivedPath` at the top level. In fact, if we ever get rid of `DrvDeep`, `NixStringContextElem` could be replaced with `SingleDerivedPath` entirely! Important note: some JSON formats have changed. We already can *produce* dynamic derivations, but we can't refer to them directly. Today, we can merely express building or example at the top imperatively over time by building `foo.drv^bar.drv`, and then with a second nix invocation doing `<result-from-first>^baz`, but this is not declarative. The ethos of Nix of being able to write down the full plan everything you want to do, and then execute than plan with a single command, and for that we need the new inductive form of these types. Co-authored-by: Robert Hensing <roberth@users.noreply.github.com> Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-04-25FormattingEelco Dolstra
2023-04-24Merge remote-tracking branch 'origin/master' into source-pathEelco Dolstra
2023-04-21Use `std::set<StringContextElem>` not `PathSet` for string contextsJohn Ericson
Motivation `PathSet` is not correct because string contexts have other forms (`Built` and `DrvDeep`) that are not rendered as plain store paths. Instead of wrongly using `PathSet`, or "stringly typed" using `StringSet`, use `std::std<StringContextElem>`. ----- In support of this change, `NixStringContext` is now defined as `std::std<StringContextElem>` not `std:vector<StringContextElem>`. The old definition was just used by a `getContext` method which was only used by the eval cache. It can be deleted altogether since the types are now unified and the preexisting `copyContext` function already suffices. Summarizing the previous paragraph: Old: - `value/context.hh`: `NixStringContext = std::vector<StringContextElem>` - `value.hh`: `NixStringContext Value::getContext(...)` - `value.hh`: `copyContext(...)` New: - `value/context.hh`: `NixStringContext = std::set<StringContextElem>` - `value.hh`: `copyContext(...)` ---- The string representation of string context elements no longer contains the store dir. The diff of `src/libexpr/tests/value/context.cc` should make clear what the new representation is, so we recommend reviewing that file first. This was done for two reasons: Less API churn: `Value::mkString` and friends did not take a `Store` before. But if `NixStringContextElem::{parse, to_string}` *do* take a store (as they did before), then we cannot have the `Value` functions use them (in order to work with the fully-structured `NixStringContext`) without adding that argument. That would have been a lot of churn of threading the store, and this diff is already large enough, so the easier and less invasive thing to do was simply make the element `parse` and `to_string` functions not take the `Store` reference, and the easiest way to do that was to simply drop the store dir. Space usage: Dropping the `/nix/store/` (or similar) from the internal representation will safe space in the heap of the Nix programming being interpreted. If the heap contains many strings with non-trivial contexts, the saving could add up to something significant. ---- The eval cache version is bumped. The eval cache serialization uses `NixStringContextElem::{parse, to_string}`, and since those functions are changed per the above, that means the on-disk representation is also changed. This is simply done by changing the name of the used for the eval cache from `eval-cache-v4` to eval-cache-v5`. ---- To avoid some duplication `EvalCache::mkPathString` is added to abstract over the simple case of turning a store path to a string with just that string in the context. Context This PR picks up where #7543 left off. That one introduced the fully structured `NixStringContextElem` data type, but kept `PathSet context` as an awkward middle ground between internal `char[][]` interpreter heap string contexts and `NixStringContext` fully parsed string contexts. The infelicity of `PathSet context` was specifically called out during Nix team group review, but it was agreeing that fixing it could be left as future work. This is that future work. A possible follow-up step would be to get rid of the `char[][]` evaluator heap representation, too, but it is not yet clear how to do that. To use `NixStringContextElem` there we would need to get the STL containers to GC pointers in the GC build, and I am not sure how to do that. ---- PR #7543 effectively is writing the inverse of a `mkPathString`, `mkOutputString`, and one more such function for the `DrvDeep` case. I would like that PR to have property tests ensuring it is actually the inverse as expected. This PR sets things up nicely so that reworking that PR to be in that more elegant and better tested way is possible. Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
2023-04-06Backport SourcePath from the lazy-trees branchEelco Dolstra
This introduces the SourcePath type from lazy-trees as an abstraction for accessing files from inputs that may not be materialized in the real filesystem (e.g. Git repositories). Currently, however, it's just a wrapper around CanonPath, so it shouldn't change any behaviour. (On lazy-trees, SourcePath is a <InputAccessor, CanonPath> tuple.)
2023-01-19Revert "Revert "Merge pull request #6204 from layus/coerce-string""Guillaume Maudoux
This reverts commit 9b33ef3879a764bed4cc2404a08344c3a697a646.
2023-01-18Revert "Merge pull request #6204 from layus/coerce-string"Robert Hensing
This reverts commit a75b7ba30f1e4f8b15e810fd18e63ee9552e0815, reversing changes made to 9af16c5f742300e831a2cc400e43df1e22f87f31.
2023-01-10Parse string context elements properlyJohn Ericson
Prior to this change, we had a bunch of ad-hoc string manipulation code scattered around. This made it hard to figure out what data model for string contexts is. Now, we still store string contexts most of the time as encoded strings --- I was wary of the performance implications of changing that --- but whenever we parse them we do so only through the `NixStringContextElem::parse` method, which handles all cases. This creates a data type that is very similar to `DerivedPath` but: - Represents the funky `=<drvpath>` case as properly distinct from the others. - Only encodes a single output, no wildcards and no set, for the "built" case. (I would like to deprecate `=<path>`, after which we are in spitting distance of `DerivedPath` and could maybe get away with fewer types, but that is another topic for another day.)
2023-01-02Merge remote-tracking branch 'origin/master' into coerce-stringEelco Dolstra
2022-12-07Trivial changes from the lazy-trees branchEelco Dolstra
2022-10-25Rework error throwing, and test itGuillaume Maudoux
2022-10-22Introduce an Error builder to tackle complexityGuillaume Maudoux
2022-09-11fix remaining foo stuffGuillaume Maudoux
2022-09-11Cleanup error strings rebaseGuillaume Maudoux
2022-09-07WIP: broken merge but need a git checkpointGuillaume Maudoux
2022-08-24Fix evaluation cacheEelco Dolstra
98e361ad4c1a26d4ffe4762a6f33bb9e39321a39 introduced a regression where previously stored attributes were replaced by placeholders. As a result, a command like 'nix build nixpkgs#hello' had to be executed at least twice to get caching. This code does not seem necessary for suggestions to work.
2022-07-12Fix debug messageEelco Dolstra
2022-06-23eval-cache: cast rowId to correct typeRick van Schijndel
Prevents errors when running with UBSan: /nix/store/j5vhrywqmz1ixwhsmmjjxa85fpwryzh0-gcc-11.3.0/include/c++/11.3.0/bits/stl_pair.h:353:4: runtime error: load of value 229, which is not a valid value for type 'AttrType'
2022-05-25Merge branch 'master' into debug-exploratory-PRBen Burdette
2022-05-25Style tweaksEelco Dolstra
2022-05-16Make nix::eval_cache::int_t more idiomaticThéophane Hufschmitt
Don’t explicitely give it a constructor, but use aggregate initialization instead (also prevents having an implicit coertion, which is probably good here)
2022-05-16resolve redundant priority passing, wrap NixInt in eval-cache variantEli Kogan-Wang
2022-05-16Add int to eval-cache, bump eval cache schema versionEli Kogan-Wang
2022-05-13Integrate review changesEli Kogan-Wang
2022-05-06trying debugThrowBen Burdette
2022-05-05Merge branch 'NixOS:master' into debug-exploratory-PRBen Burdette
2022-05-04Add forgotten null checkAlexander Shpilkin
2022-05-04Merge remote-tracking branch 'origin/master' into debug-exploratory-PREelco Dolstra
2022-04-29Merge remote-tracking branch 'origin/master' into coerce-stringGuillaume Maudoux
2022-04-28Merge branch 'master' into debug-merge-masterBen Burdette
2022-04-28fix errors case and wordingGuillaume Maudoux
2022-04-26Bump eval cache schema versionEelco Dolstra
2022-04-26nix: Respect meta.outputsToInstall, and use all outputs by defaultEelco Dolstra
'nix profile install' will now install all outputs listed in the package's meta.outputsToInstall attribute, or all outputs if that attribute doesn't exist. This makes it behave consistently with nix-env. Fixes #6385. Furthermore, for consistency, all other 'nix' commands do this as well. E.g. 'nix build' will build and symlink the outputs in meta.outputsToInstall, defaulting to all outputs. Previously, it only built/symlinked the first output. Note that this means that selecting a specific output using attrpath selection (e.g. 'nix build nixpkgs#libxml2.dev') no longer works. A subsequent PR will add a way to specify the desired outputs explicitly.
2022-04-26EvalCache AttrKey: Use Symbol instead of std::stringEelco Dolstra
2022-04-26EvalCache: Revert to using symbols in getAttr()Eelco Dolstra
2022-04-25rename SymbolIdx -> Symbol, Symbol -> SymbolStrpennae
after #6218 `Symbol` no longer confers a uniqueness invariant on the string it wraps, it is now possible to create multiple symbols that compare equal but whose string contents have different addresses. this guarantee is now only provided by `SymbolIdx`, leaving `Symbol` only as a string wrapper that knows about the intricacies of how symbols need to be formatted for output. this change renames `SymbolIdx` to `Symbol` to restore the previous semantics of `Symbol` to that name. we also keep the wrapper type and rename it to `SymbolStr` instead of returning plain strings from lookups into the symbol table because symbols are formatted for output in many places. theoretically we do not need `SymbolStr`, only a function that formats a string for output as a symbol, but having to wrap every symbol that appears in a message into eg `formatSymbol()` is error-prone and inconvient.
2022-04-21store Symbols in a table as well, like positionspennae
this slightly increases the amount of memory used for any given symbol, but this increase is more than made up for if the symbol is referenced more than once in the EvalState that holds it. on average every symbol should be referenced at least twice (once to introduce a binding, once to use it), so we expect no increase in memory on average. symbol tables are limited to 2³² entries like position tables, and similar arguments apply to why overflow is not likely: 2³² symbols would require as many string instances (at 24 bytes each) and map entries (at 24 bytes or more each, assuming that the map holds on average at most one item per bucket as the docs say). a full symbol table would require at least 192GB of memory just for symbols, which is well out of reach. (an ofborg eval of nixpks today creates less than a million symbols!)
2022-04-14Make InstallableFlake::toValue() and toDerivation() behave consistentlyEelco Dolstra
In particular, this means that 'nix eval` (which uses toValue()) no longer auto-calls functions or functors (because AttrCursor::findAlongAttrPath() doesn't). Fixes #6152. Also use ref<> in a few places, and don't return attrpaths from getCursor() because cursors already have a getAttrPath() method.
2022-04-08move throw to preverve Error type; turn off debugger for tryEvalBen Burdette
2022-04-07Merge remote-tracking branch 'upstream/master' into upstream-mergeBen Burdette
2022-03-18Decode string context straight to using `StorePath`sJohn Ericson
I gather decoding happens on demand, so I hope don't think this should have any perf implications one way or the other.
2022-03-18Merge remote-tracking branch 'origin/master' into coerce-stringGuillaume Maudoux