aboutsummaryrefslogtreecommitdiff
path: root/src/libcmd/installable-flake.cc
AgeCommit message (Collapse)Author
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: Delete remaining file and clean up headersTom Hubrecht
Change-Id: Ic1f68e6af658e94ef7922841dd3ad4c69551ef56
2024-05-21print type and value in "flake attr is not a derivation" errorsQyriad
This turns errors like: error: flake output attribute 'hydraJobs' is not a derivation or path into errors like: error: expected flake output attribute 'hydraJobs' to be a derivation or path but found a set: { binaryTarball = «thunk»; build = «thunk»; etc> } This change affects all InstallableFlake commands. Change-Id: I899757af418b6f98201006ec6ee13a448c07077c
2024-03-25feat: notation to refer to no attribute search prefixTom Bereknyei
An attrPath prefix of "." indicates no need to try default attrPath prefixes. For example `nixpkgs#legacyPackages.x86_64-linux.ERROR` searches through ``` trying flake output attribute 'packages.x86_64-linux.legacyPackages.x86_64-linux.ERROR' using cached attrset attribute '' trying flake output attribute 'legacyPackages.x86_64-linux.legacyPackages.x86_64-linux.ERROR' using cached attrset attribute 'legacyPackages.x86_64-linux' trying flake output attribute 'legacyPackages.x86_64-linux.ERROR' using cached attrset attribute 'legacyPackages.x86_64-linux' ``` And there is no way to specify that one does not want the automatic search behavior. Now one can specify `nixpkgs#.legacyPackages.x86_64-linux.ERROR` to only refer to the rooted attribute path without any default injection of attribute search path or system. Change-Id: Iac1334e1470137b7ce11dcf845513810230638ec (cherry picked from commit d4aed18883b361133607296fb6cd789c47427a38)
2024-03-04Merge pull request #9582 from pennae/misc-optseldritch horrors
a packet of small optimizations (cherry picked from commit ee439734e924eb337a869ff2e48aff8b989198bc) Change-Id: I125d870710750a32a0dece48f39a3e9132b0d023
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>
2023-07-03Rename 'resolvedRef' to 'lockedRef'Eelco Dolstra
'resolvedRef' was incorrect, since a resolved ref is one after registry resolution, which may still be unlocked (e.g. 'nixpkgs' -> 'github:NixOS/nixpkgs').
2023-05-15Make more string values work as installablesJohn Ericson
As discussed in #7417, it would be good to make more string values work as installables. That is to say, if an installable refers to a value, and the value is a string, it used to not work at all, since #7484, it works somewhat, and this PR make it work some more. The new cases that are added for `BuiltPath` contexts: - Fixed input- or content-addressed derivation: ``` nix-repl> hello.out.outPath "/nix/store/jppfl2bp1zhx8sgs2mgifmsx6dv16mv2-hello-2.12" nix-repl> :p builtins.getContext hello.out.outPath { "/nix/store/c7jrxqjhdda93lhbkanqfs07x2bzazbm-hello-2.12.drv" = { outputs = [ "out" ]; }; } The string matches the specified single output of that derivation, so it should also be valid. - Floating content-addressed derivation: ``` nix-repl> (hello.overrideAttrs (_: { __contentAddressed = true; })).out.outPath "/1a08j26xqc0zm8agps8anxpjji410yvsx4pcgyn4bfan1ddkx2g0" nix-repl> :p builtins.getContext (hello.overrideAttrs (_: { __contentAddressed = true; })).out.outPath { "/nix/store/qc645pyf9wl37c6qvqzaqkwsm1gp48al-hello-2.12.drv" = { outputs = [ "out" ]; }; } ``` The string is not a path but a placeholder, however it also matches the context, and because it is a CA derivation we have no better option. This should also be valid. We may also want to think about richer attrset based values (also discussed in that issue and #6507), but this change "completes" our string-based building blocks, from which the others can be desugared into or at least described/document/taught in terms of. Progress towards #7417 Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-05-10Fix `nix print-dev-env` & `nix develop` with drv pathsJohn Ericson
Fixes #8309 This regression was because both `CmdDevelop` and `CmdPrintDevEnv` were switched to be `InstallableValueCommand` subclasses, but actually neither should have been. The `nixpkgsFlakeRef` method should indeed not be on the base installable class, because "flake refs" and "nixpkgs" are not installable-wide notions, but that doesn't mean these commands should only accept installable values.
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.)
2023-03-24Stratify `ExtraPathInfo` along `Installable` hierarchyJohn Ericson
Instead of having a bunch of optional fields, have a few subclasses which can have mandatory fields. Additionally, the new `getExtraPathInfo`, and `nixpkgsFlakeRef`, are moved to `InstallableValue`. I did these things because https://github.com/NixOS/rfcs/pull/134 ; with these things moved to `InstallableValue`, the base `Installable` no longer depends on libexpr! This is a major step towards that. Also, add a bunch of doc comments for sake of the internal API docs.
2023-03-04InstallableFlake: Apply nix config in `getCursors`amesgen
2023-02-20Split out `InstallableFlake` and `InstallableAttrPath`John Ericson