aboutsummaryrefslogtreecommitdiff
path: root/src/libexpr/nixexpr.hh
AgeCommit message (Collapse)Author
2022-04-26Don't pass Symbol by referenceEelco Dolstra
Since Symbol is just an integer, passing it by const reference is never advantageous.
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.
2022-04-22Move ChunkedVector to its own headerThéophane Hufschmitt
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!)
2022-04-21don't use Symbol in Pos to represent a pathpennae
PosTable deduplicates origin information, so using symbols for paths is no longer necessary. moving away from path Symbols also reduces the usage of symbols for things that are not keys in attribute sets, which will become important in the future when we turn symbols into indices as well.
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.
2022-03-08make Pos smallerpennae
reduces peak hep memory use on eval of our test system from 264.4MB to 242.3MB, possibly also a slight performance boost. theoretically memory use could be cut down by another eight bytes per Pos on average by turning it into a tuple containing an index into a global base position table with row and column offsets, but that doesn't seem worth the effort at this point.
2022-02-25Remove std::string alias (for real this time)Eelco Dolstra
Also use std::string_view in a few more places.
2022-02-21Remove std::vector aliasEelco Dolstra
2022-02-04fix nix repl not overriding existing bindings in :apennae
previously :a would override old bindings of a name with new values if the added set contained names that were already bound. in nix 2.6 this doesn't happen any more, which is potentially confusing. fixes #6041
2022-01-19defer formals duplicate check for incresed efficiency all roundpennae
if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19don't use Symbols for stringspennae
string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
2022-01-19remove ExprIndStrpennae
it can be replaced with StringToken if we add another bit if information to StringToken, namely whether this string should take part in indentation scanning or not. since all escaping terminates indentation scanning we need to set this bit only for the non-escaped IND_STRING rule. this improves performance by about 1%. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.880 s ± 0.048 s [User: 6.809 s, System: 1.643 s] Range (min … max): 8.781 s … 8.993 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 375.0 ms ± 2.2 ms [User: 339.8 ms, System: 35.2 ms] Range (min … max): 371.5 ms … 379.3 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.831 s ± 0.040 s [User: 2.536 s, System: 0.225 s] Range (min … max): 2.769 s … 2.912 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.832 s ± 0.048 s [User: 6.757 s, System: 1.657 s] Range (min … max): 8.743 s … 8.921 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.2 ms [User: 332.7 ms, System: 34.7 ms] Range (min … max): 364.6 ms … 374.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs
2022-01-04Turn mkString(Symbol) into a methodEelco Dolstra
2022-01-04Remove non-method mk<X> functionsEelco Dolstra
2021-12-27Fix accidental O(n^2 * log n) performance in NixRepl::addAttrsToScopeYorick van Pelt
Only sort once, after adding all of the attrs first. This reduces my `nix repl '<nixpkgs>'` loading time from 1.07s to 103ms. Fixes #5823
2021-12-13Merge branch 'better-interpolation-error-location' of ↵Eelco Dolstra
https://github.com/greedy/nix
2021-11-04Add level / displacement typesEelco Dolstra
2021-11-04Optimize primop callsEelco Dolstra
We now parse function applications as a vector of arguments rather than as a chain of binary applications, e.g. 'substring 1 2 "foo"' is parsed as ExprCall { .fun = <substring>, .args = [ <1>, <2>, <"foo"> ] } rather than ExprApp (ExprApp (ExprApp <substring> <1>) <2>) <"foo"> This allows primops to be called immediately (if enough arguments are supplied) without having to allocate intermediate tPrimOpApp values. On $ nix-instantiate --dry-run '<nixpkgs/nixos/release-combined.nix>' -A nixos.tests.simple.x86_64-linux this gives a substantial performance improvement: user CPU time: median = 0.9209 mean = 0.9218 stddev = 0.0073 min = 0.9086 max = 0.9340 [rejected, p=0.00000, Δ=-0.21433±0.00677] elapsed time: median = 1.0585 mean = 1.0584 stddev = 0.0024 min = 1.0523 max = 1.0623 [rejected, p=0.00000, Δ=-0.20594±0.00236] because it reduces the number of tPrimOpApp allocations from 551990 to 42534 (i.e. only small minority of primop calls are partially applied) which in turn reduces time spent in the garbage collector.
2021-11-04StaticEnv: Use std::vector instead of std::mapEelco Dolstra
2021-10-06libexpr: remove matchAttrs boolean from ExprLambdaAndreas Rammhold
The boolean is only used to determine if the formals are set to a non-null pointer in all our cases. We can get rid of that allocation and instead just compare the pointer value with NULL. Saving up to sizeof(bool) + platform specific alignment per ExprLambda instace. Probably not a lot of memory but perhaps a few kilobyte with nixpkgs? This also gets rid of a potential issue with dereferencing formals based on the value of the boolean that didn't have to be aligned with the formals pointer but was in all our cases.
2021-09-22Better eval error locations for interpolation and +Geoff Reedy
Previously, type or coercion errors for string interpolation, path interpolation, and plus expressions were always reported at the beginning of the outer expression. This leads to confusing evaluation error messages making it hard to accurately diagnose and then fix the error. For example, errors were reported as follows. ``` cannot coerce an integer to a string 1| let foo = 7; in "bar" + foo | ^ cannot add a string to an integer 1| let foo = "bar"; in 4 + foo | ^ cannot coerce an integer to a string 1| let foo = 7; in "x${foo}" | ^ ``` This commit changes the ExprConcatStrings expression vector to store a sequence of expressions *and* their expansion locations so that error locations can be reported accurately. For interpolation, the error is reported at the beginning of the entire `${foo}`, not at the beginning of `foo` because I thought this was slightly clearer. The previous errors are now reported as: ``` cannot coerce an integer to a string 1| let foo = 7; in "bar" + foo | ^ cannot add a string to an integer 1| let foo = "bar"; in 4 + foo | ^ cannot coerce an integer to a string 1| let foo = 7; in "x${foo}" | ^ ``` The error is reported at this kind of precise location even for multi-line indented strings. This probably helps with at least some of the cases mentioned in #561
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.
2021-02-22Make missing auto-call arguments throw an eval errorregnat
The PR #4240 changed messag of the error that was thrown when an auto-called function was missing an argument. However this change also changed the type of the error, from `EvalError` to a new `MissingArgumentError`. This broke hydra which was relying on an `EvalError` being thrown. Make `MissingArgumentError` a subclass of `EvalError` to un-break hydra.
2021-01-21Improve error formattingEelco Dolstra
Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-15Merge pull request #4240 from bburdette/2259-error-messageDomen Kožar
2259 error message - "auto-call" error
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
2020-11-11missing argument errorBen Burdette
2020-06-23use plain errPos instead of nixCode; fix testsBen Burdette
2020-06-18Merge branch 'master' into caveman-LOCsBen Burdette
2020-06-15Get rid of explicit ErrorInfo constructorsEelco Dolstra
2020-05-20print LOC for stdin, string argsBen Burdette
2020-05-12new pos format for more errorsBen Burdette
2020-05-11fixes to merged codeBen Burdette
2020-05-11Merge branch 'master' into errors-phase-2Ben Burdette
2020-04-29uncrustify formattingBen Burdette
2020-04-21remove 'format' from Error constructor callsBen Burdette
2020-04-09Attach pos to if expression errorsDomen Kožar
2020-04-02Make function arguments retain position infoSilvan Mosberger
This allows querying the location of function arguments. E.g. builtins.unsafeGetAttrPos "x" (builtins.functionArgs ({ x }: null)) => { column = 57; file = "/home/infinisil/src/nix/inst/test.nix"; line = 1; }
2019-11-10Fix extra ; warnings involving MakeErrorJohn Ericson
2018-05-11Revert "Throw a specific error for incomplete parse errors."Eelco Dolstra
This reverts commit 6498adb002bcf7e715afe46c23b8635d4592c156. We don't actually use IncompleteParseError in 'nix repl'.
2018-05-02Fix some random -Wconversion warningsEelco Dolstra
2018-03-14Fix compatibility with latest boost::formatEelco Dolstra
2018-03-09Modified MakeBinOp to no longer produce its name using concatenation and "##".Tim Engler
Doing so prevents emacs tags from working, as well as makes the code extremely confusing for a newbie. In the prior state, if someone wants to find the definition of "ExprApp" for example, a grep through the code reveals nothing. Since the definition could be hiding in numerous ".h" files, it's really difficult to find. This personally took me several hours to figure out.
2017-07-30Replace Unicode quotes in user-facing strings by ASCIIJörg Thalheim
Relevant RFC: NixOS/rfcs#4 $ ag -l | xargs sed -i -e "/\"/s/’/'/g;/\"/s/‘/'/g"
2016-11-26Revert "Get rid of unicode quotes (#1140)"Eelco Dolstra
This reverts commit f78126bfd6b6c8477fcdbc09b2f98772dbe9a1e7. There really is no need for such a massive change...
2016-11-25Get rid of unicode quotes (#1140)Guillaume Maudoux
2016-02-24Throw a specific error for incomplete parse errors.Scott Olson
`nix-repl` will use this for deciding whether to keep waiting for input or error out right away.
2016-01-05First hit at providing support for floats in the language.Christian Theune
2015-02-23Add restricted evaluation modeEelco Dolstra
If ‘--option restrict-eval true’ is given, the evaluator will throw an exception if an attempt is made to access any file outside of the Nix search path. This is primarily intended for Hydra, where we don't want people doing ‘builtins.readFile ~/.ssh/id_dsa’ or stuff like that.