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2023-07-01Merge pull request #8566 from inclyc/nixd/value-print-depthRobert Hensing
libexpr: extend `Value::print` to allow limited depth
2023-06-27Automatically document builtin constantsJohn Ericson
This is done in roughly the same way builtin functions are documented. Also auto-link experimental features for primops, subsuming PR #8371. Co-authored-by: Eelco Dolstra <edolstra@gmail.com> Co-authored-by: Robert Hensing <roberth@users.noreply.github.com> Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-06-22libexpr: extend `Value::print` to allow limited depthYingchi Long
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>
2023-04-17Merge remote-tracking branch 'upstream/master' into source-pathRobert Hensing
2023-04-07Finish converting existing comments for internal API docs (#8146)John Ericson
* Finish converting existing comments for internal API docs 99% of this was just reformatting existing comments. Only two exceptions: - Expanded upon `BuildResult::status` compat note - Split up file-level `symbol-table.hh` doc comments to get per-definition docs Also fixed a few whitespace goofs, turning leading tabs to spaces and removing trailing spaces. Picking up from #8133 * Fix two things from comments * Use triple-backtick not indent for `dumpPath` * Convert GNU-style `\`..'` quotes to markdown style in API docs This will render correctly.
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.)
2023-03-31Ensure all headers have `#pragma once` and are in API docsJohn Ericson
`///@file` makes them show up in the internal API dos. A tiny few were missing `#pragma once`.
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
2022-11-16Replace src/libutil/json.cc with nlohmann json generationYorick van Pelt
2022-09-07WIP: broken merge but need a git checkpointGuillaume Maudoux
2022-08-22JSON: 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
2022-05-26Remove pre-C++11 hackinessEelco Dolstra
2022-04-29Merge remote-tracking branch 'origin/master' into coerce-stringGuillaume Maudoux
2022-04-28No point in passing string_views by referenceGuillaume Maudoux
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!)
2022-04-21replace 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.
2022-03-22Don't hide repeated values while generating manifest.nixEelco Dolstra
Fixes #6243.
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.
2022-03-18Refactor to use more traces and less string manipulationsGuillaume Maudoux
2022-03-11Create some type aliases for string ContextsJohn Ericson
2022-03-04Add detailed error mesage for coerceTo{String,Path}Guillaume Maudoux
2022-03-03Be more aggressive in hiding repeated valuesEelco Dolstra
We now memoize on Bindings / list element vectors rather than Values, so that e.g. two Values that point to the same Bindings will be printed only once.
2022-03-03printValue(): Don't show repeated valuesEelco Dolstra
Fixes #6157.
2022-02-21Remove std::string aliasEelco Dolstra
2022-02-04Make most calls to determinePos() lazyEelco Dolstra
2022-01-12optimize ExprConcatStrings::evalpennae
constructing an ostringstream for non-string concats (like integer addition) is a small constant cost that we can avoid. for string concats we can keep all the string temporaries we get from coerceToString and concatenate them in one go, which saves a lot of intermediate temporaries and copies in ostringstream. we can also avoid copying the concatenated string again by directly allocating it in GC memory and moving ownership of the concatenated string into the target value. saves about 2% on system eval. before: Benchmark 1: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.837 s ± 0.031 s [User: 2.562 s, System: 0.191 s] Range (min … max): 2.796 s … 2.892 s 20 runs after: Benchmark 1: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.790 s ± 0.035 s [User: 2.532 s, System: 0.187 s] Range (min … max): 2.722 s … 2.836 s 20 runs
2022-01-04Turn mkString(Symbol) into a methodEelco Dolstra
2022-01-04Remove non-method mkPath()Eelco Dolstra
2022-01-04Remove non-method mk<X> functionsEelco Dolstra
2022-01-04Remove non-method mkString()Eelco Dolstra
2022-01-04Ensure that attrsets are sortedEelco Dolstra
Previously you had to remember to call value->attrs->sort() after populating value->attrs. Now there is a BindingsBuilder helper that wraps Bindings and ensures that sort() is called before you can use it.
2021-12-02Introduce builtins.groupBy primopSilvan Mosberger
This function is very useful in nixpkgs, but its implementation in Nix itself is rather slow due to it requiring a lot of attribute set and list appends.
2021-11-25Support range-based for loop over list valuesEelco Dolstra
2021-11-13toXML: display errors positionKevin Amado
- This change applies to builtins.toXML and inner workings - Proof of concept: ```nix let e = builtins.toXML e; in e ``` - Before: ``` $ nix-instantiate --eval poc.nix error: infinite recursion encountered ``` - After: ``` $ nix-instantiate --eval poc.nix error: infinite recursion encountered at /data/github/kamadorueda/nix/poc.nix:1:9: 1| let e = builtins.toXML e; in e | ```
2021-04-13libexpr: misc improvements for proper error positionMaximilian Bosch
When working on some more complex Nix code, there are sometimes rather unhelpful or misleading error messages, especially if coerce-errors are thrown. This patch is a first steps towards improving that. I'm happy to file more changes after that, but I'd like to gather some feedback first. To summarize, this patch does the following things: * Attrsets (a.k.a. `Bindings` in `libexpr`) now have a `Pos`. This is helpful e.g. to identify which attribute-set in `listToAttrs` is invalid. * The `Value`-struct has a new method named `determinePos` which tries to guess the position of a value and falls back to a default if that's not possible. This can be used to provide better messages if a coercion fails. * The new `determinePos`-API is used by `builtins.concatMap` now. With that change, Nix shows the exact position in the error where a wrong value was returned by the lambda. To make sure it's still obvious that `concatMap` is the problem, another stack-frame was added. * The changes described above can be added to every other `primop`, but first I'd like to get some feedback about the overall approach.
2020-12-18Replace Value type setters with mk* functionsSilvan Mosberger
Move clearValue inside Value mkInt instead of setInt mkBool instead of setBool mkString instead of setString mkPath instead of setPath mkNull instead of setNull mkAttrs instead of setAttrs mkList instead of setList* mkThunk instead of setThunk mkApp instead of setApp mkLambda instead of setLambda mkBlackhole instead of setBlackhole mkPrimOp instead of setPrimOp mkPrimOpApp instead of setPrimOpApp mkExternal instead of setExternal mkFloat instead of setFloat Add note that the static mk* function should be removed eventually
2020-12-17Rename Value::normalType() -> Value::type()Silvan Mosberger
2020-12-17Rename ValueType -> InternalType, NormalType -> ValueTypeSilvan Mosberger
And Value::type to Value::internalType, such that type() can be used in the next commit to get the new ValueType
2020-12-12Make Value::type privateSilvan Mosberger
This is an implementation detail and shouldn't be used. Use normalType() and the various is<Type> functions instead
2020-12-12Add ValueType checking functions for types that have the same NormalTypeSilvan Mosberger
2020-12-12Introduce Value type setters and make use of themSilvan Mosberger
2020-12-12Introduce NormalType for the normal type of a ValueSilvan Mosberger
This will be useful to abstract over the ValueType implementation details Make use of it already to replace the showType(ValueType) function
2020-06-29EvalCache: Store string contextsEelco Dolstra
2020-04-16Merge remote-tracking branch 'origin/master' into flakesEelco Dolstra
2020-04-16ValueMap, VectorVector: Use traceable_allocatorEelco Dolstra
We want to *trace* the 'Value *' arrays, not garbage-collect them! Otherwise the vectors/maps can end up pointing to nowhere. Fixes #3377. Closes #3384.