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2024-06-20de-inheritance CmdEval for InstallableValueCommandQyriad
Change-Id: I08b1702310e863d15de26dc838eb0bcb62417c10
2024-05-08nix3-eval: don't elide top-level errorsQyriad
Fixes #276. Change-Id: I83e71beb5c35d6f3b10a4186caa5e52a2f95b510
2024-03-10Merge "Print derivation paths in `nix eval`" into mainjade
2024-03-09Merge pull request #9925 from 9999years/fmt-cleanupeldritch horrors
Cleanup `fmt.hh` (cherry picked from commit 47a1dbb4b8e7913cbb9b4d604728b912e76e4ca0) Change-Id: Id076a45cb39652f437fe3f8bda10c310a9894777
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
2024-03-08Print derivation paths in `nix eval`Rebecca Turner
`nix eval` forces values and prints derivations as attribute sets, so commands that print derivations (e.g. `nix eval nixpkgs#bash`) will infinitely loop and segfault. Printing derivations as `.drv` paths makes `nix eval` complete as expected. Further work is needed, but this is better than a segfault. (cherry picked from commit 4910d74086a85876e093136a0e8ebc547b467af7) Change-Id: I8e1cb39c05db812080759ec183ee7a131760e6ea
2024-03-09Merge pull request #9753 from 9999years/print-value-on-type-erroreldritch horrors
Print the value in `value is X while a Y is expected` error (cherry picked from commit 5f72a97092da6af28a7d2b2a50d74e9d34fae7e1) Change-Id: Idb4bc903ae59a0f5b6fb3b1da4d47970fe0a6efe
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.)
2023-03-16Move value-only methods to `InstallableValue`John Ericson
These methods would previously fail on the other `Installable`s, so moving them to this class is more correct as to where they actually work. Additionally, a `InstallableValueCommand` is created to make it easier (or rather no worse than before) to write commands that just work on `InstallableValue`s. Besides being a cleanup to avoid failing default methods, this gets us closer to https://github.com/NixOS/rfcs/pull/134.
2023-03-15Make command infra less stateful and more regularJohn Ericson
Already, we had classes like `BuiltPathsCommand` and `StorePathsCommand` which provided alternative `run` virtual functions providing the implementation with more arguments. This was a very nice and easy way to make writing command; just fill in the virtual functions and it is fairly clear what to do. However, exception to this pattern were `Installable{,s}Command`. These two classes instead just had a field where the installables would be stored, and various side-effecting `prepare` and `load` machinery too fill them in. Command would wish out those fields. This isn't so clear to use. What this commit does is make those command classes like the others, with richer `run` functions. Not only does this restore the pattern making commands easier to write, it has a number of other benefits: - `prepare` and `load` are gone entirely! One command just hands just hands off to the next. - `useDefaultInstallables` because `defaultInstallables`. This takes over `prepare` for the one case that needs it, and provides enough flexiblity to handle `nix repl`'s idiosyncratic migration. - We can use `ref` instead of `std::shared_ptr`. The former must be initialized (so it is like Rust's `Box` rather than `Option<Box>`, This expresses the invariant that the installable are in fact initialized much better. This is possible because since we just have local variables not fields, we can stop worrying about the not-yet-initialized case. - Fewer lines of code! (Finally I have a large refactor that makes the number go down not up...) - `nix repl` is now implemented in a clearer way. The last item deserves further mention. `nix repl` is not like the other installable commands because instead working from once-loaded installables, it needs to be able to load them again and again. To properly support this, we make a new superclass `RawInstallablesCommand`. This class has the argument parsing and completion logic, but does *not* hand off parsed installables but instead just the raw string arguments. This is exactly what `nix repl` needs, and allows us to instead of having the logic awkwardly split between `prepare`, `useDefaultInstallables,` and `load`, have everything right next to each other. I think this will enable future simplifications of that argument defaulting logic, but I am saving those for a future PR --- best to keep code motion and more complicated boolean expression rewriting separate steps. The "diagnostic ignored `-Woverloaded-virtual`" pragma helps because C++ doesn't like our many `run` methods. In our case, we don't mind the shadowing it all --- it is *intentional* that the derived class only provides a `run` method, and doesn't call any of the overridden `run` methods. Helps with https://github.com/NixOS/rfcs/pull/134
2023-03-02Get rid of some unchecked calls to std::coutEelco Dolstra
2023-02-20Make `--read-only` a separate mixinJohn Ericson
It is independent of SourceExprCommand, which is about parsing installables, except for the fact that parsing installables is one of the many things influenced by read-only mode.
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.
2023-01-02Merge remote-tracking branch 'origin/master' into coerce-stringEelco Dolstra
2022-12-05Consistent capitalisationEelco Dolstra
2022-11-16Replace src/libutil/json.cc with nlohmann json generationYorick van Pelt
2022-09-07WIP: broken merge but need a git checkpointGuillaume Maudoux
2022-08-22JSON: add missing newlinesNaïm Favier
after `nix eval --json` and `nix-instantiate --eval --json`.
2022-08-22JSON: print paths as strings without copying them to the storeNaïm Favier
Makes `printValueAsJSON` not copy paths to the store for `nix eval --json`, `nix-instantiate --eval --json` and `nix-env --json`. Fixes https://github.com/NixOS/nix/issues/5612
2022-04-29Merge remote-tracking branch 'origin/master' into coerce-stringGuillaume Maudoux
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!)
2022-04-21replace most Pos objects/ptrs with indexes into a position tablepennae
Pos objects are somewhat wasteful as they duplicate the origin file name and input type for each object. on files that produce more than one Pos when parsed this a sizeable waste of memory (one pointer per Pos). the same goes for ptr<Pos> on 64 bit machines: parsing enough source to require 8 bytes to locate a position would need at least 8GB of input and 64GB of expression memory. it's not likely that we'll hit that any time soon, so we can use a uint32_t index to locate positions instead.
2022-03-26nix eval: Add option `read-only`Erik Arvstedt
2022-03-18Revert extra colon at end os stringsGuillaume Maudoux
2022-03-07more fixesGuillaume Maudoux
2022-03-04Add detailed error mesage for coerceTo{String,Path}Guillaume Maudoux
2022-02-04Merge branch 'issue-3505' of https://github.com/kamadorueda/nixEelco Dolstra
2022-01-27optionally return string_view from coerceToStringpennae
we'll retain the old coerceToString interface that returns a string, but callers that don't need the returned value to outlive the Value it came from can save copies by using the new interface instead. for values that weren't stringy we'll pass a new buffer argument that'll be used for storage and shouldn't be inspected.
2022-01-21forceValue: make pos mandatoryKevin Amado
- Make passing the position to `forceValue` mandatory, this way we remember people that the position is important for better error messages - Add pos to all `forceValue` calls
2021-10-25toJSON: report error position for fancier outputShay Bergmann
Given flake: ```nix { description = "nix json error provenance"; inputs = {}; outputs = { self }: { jsonFunction = _: "function"; json = builtins.toJSON (_: "function"); }; } ``` - Before: ```console ❯ nix eval --json .#jsonFunction error: cannot convert a function to JSON ``` - After: ```console ❯ nix eval --json .#jsonFunction error: cannot convert a function to JSON at /nix/store/b7imf1c2j4jnkg3ys7fsfbj02s5j0i4f-source/testflake/flake.nix:4:5: 3| outputs = { self }: { 4| jsonFunction = _: "function"; | ^ 5| json = builtins.toJSON (_: "function"); ```
2021-01-27Remove mkFlag()Eelco Dolstra
2021-01-13Convert option descriptions to MarkdownEelco Dolstra
2020-12-21Add 'nix eval' manpageEelco Dolstra
2020-12-17Rename Value::normalType() -> Value::type()Silvan Mosberger
2020-12-12Use Value::normalType on all forced values instead of Value::typeSilvan Mosberger
2020-12-02nix eval: Add option to write a directoryEelco Dolstra
This is useful for generating the nix manpages, but it may have other applications (like generating configuration files without a Nix store).
2020-10-09Merge remote-tracking branch 'upstream/master' into fix-and-ci-static-buildsJohn Ericson
2020-10-06Remove static variable name clashesEelco Dolstra
This was useful for an experiment with building Nix as a single compilation unit. It's not very useful otherwise but also doesn't hurt...
2020-09-25stdout_ -> coutJohn Ericson
Better to get creative than just sprinkle arbitrary underscores.
2020-07-30Merge remote-tracking branch 'origin/master' into fix-and-ci-static-buildsMatthew Bauer
2020-06-29Rename logging->stdout to logging->stdout_Matthew Bauer
musl doesn't like this identifier
2020-06-17nix eval: Add --apply flag for post-processing the resultEelco Dolstra
2020-05-05Merge remote-tracking branch 'origin/master' into flakesEelco Dolstra
2020-05-05nix --help: Group commandsEelco Dolstra
2020-04-16Use Logger::stdout()Eelco Dolstra
(cherry picked from commit 8f41847394524fcac40d3b5620139ca7e94a18e3)
2020-04-16Use Logger::stdout()Eelco Dolstra
2020-03-24nix edit: Support non-derivation attributesEelco Dolstra
E.g. $ nix edit .#nixosConfigurations.bla now works. (cherry picked from commit d2032edb2f86e955a8a7724a27c0c3225f386500)