Commit graph

687 commits

Author SHA1 Message Date
Ben Burdette 6e19947993 Merge branch 'master' into debug-merge-master 2022-04-28 12:32:57 -06:00
pennae a385e51a08 rename SymbolIdx -> Symbol, Symbol -> SymbolStr
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.
2022-04-25 15:37:01 +02:00
Théophane Hufschmitt c4ffc8e2f8
Merge pull request #6218 from pennae/pos-symbol-tables
reduce the size of Attr from 3 pointers to 2 on 64 bit machines
2022-04-22 10:28:06 +02:00
Tom Bereknyei f25112d383 fix: builtins.toFile adds path to allowedPaths
The produced path is then allowed be imported or utilized elsewhere:
```
assert (43 == import (builtins.toFile "source" "43")); "good"
```

This will still fail on write-only stores.
2022-04-21 16:41:37 -04:00
pennae 8775be3393 store Symbols in a table as well, like positions
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!)
2022-04-21 21:56:31 +02:00
pennae 00a3280232 don't use Symbol in Pos to represent a path
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.
2022-04-21 21:46:10 +02:00
pennae 6526d1676b replace most Pos objects/ptrs with indexes into a position table
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.
2022-04-21 21:46:06 +02:00
pennae 90b5c0a1a6 turn primop names into strings
we don't *need* symbols here. the only advantage they have over strings is
making call-counting slightly faster, but that's a diagnostic feature and thus
needn't be optimized.

this also fixes a move bug that previously didn't show up: PrimOp structs were
accessed after being moved from, which technically invalidates them. previously
the names remained valid because Symbol copies on move, but strings are
invalidated. we now copy the entire primop struct instead of moving since primop
registration happen once and are not performance-sensitive.
2022-04-21 21:25:17 +02:00
Ben Burdette b8b8ec7101 move throw to preverve Error type; turn off debugger for tryEval 2022-04-08 12:34:27 -06:00
Ben Burdette 1a93ac8133 Merge remote-tracking branch 'upstream/master' into upstream-merge 2022-04-07 13:42:01 -06:00
Eelco Dolstra fdfe737867 Fix handling of outputHash when outputHashAlgo is not specified
https://hydra.nixos.org/build/171351131
2022-04-01 12:40:49 +02:00
Eelco Dolstra 7537097284 Provide default values for outputHashAlgo and outputHashMode 2022-03-31 16:56:44 +02:00
Eelco Dolstra 5cd72598fe Add support for impure derivations
Impure derivations are derivations that can produce a different result
every time they're built. Example:

  stdenv.mkDerivation {
    name = "impure";
    __impure = true; # marks this derivation as impure
    outputHashAlgo = "sha256";
    outputHashMode = "recursive";
    buildCommand = "date > $out";
  };

Some important characteristics:

* This requires the 'impure-derivations' experimental feature.

* Impure derivations are not "cached". Thus, running "nix-build" on
  the example above multiple times will cause a rebuild every time.

* They are implemented similar to CA derivations, i.e. the output is
  moved to a content-addressed path in the store. The difference is
  that we don't register a realisation in the Nix database.

* Pure derivations are not allowed to depend on impure derivations. In
  the future fixed-output derivations will be allowed to depend on
  impure derivations, thus forming an "impurity barrier" in the
  dependency graph.

* When sandboxing is enabled, impure derivations can access the
  network in the same way as fixed-output derivations. In relaxed
  sandboxing mode, they can access the local filesystem.
2022-03-31 13:43:20 +02:00
Théophane Hufschmitt 390269ed87 Simplify the handling of the hash modulo
Rather than having four different but very similar types of hashes, make
only one, with a tag indicating whether it corresponds to a regular of
deferred derivation.

This implies a slight logical change: The original Nix+multiple-outputs
model assumed only one hash-modulo per derivation. Adding
multiple-outputs CA derivations changed this as these have one
hash-modulo per output. This change is now treating each derivation as
having one hash modulo per output.
This obviously means that we internally loose the guaranty that
all the outputs of input-addressed derivations have the same hash
modulo. But it turns out that it doesn’t matter because there’s nothing
in the code taking advantage of that fact (and it probably shouldn’t
anyways).

The upside is that it is now much easier to work with these hashes, and
we can get rid of a lot of useless `std::visit{ overloaded`.

Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
2022-03-29 18:17:35 +02:00
Eelco Dolstra 86b05ccd54 Only provide builtin.{getFlake,fetchClosure} is the corresponding experimental feature is enabled
This allows writing fallback code like

  if builtins ? fetchClosure then
    builtins.fetchClose { ... }
  else
    builtins.storePath ...
2022-03-25 14:04:18 +01:00
Eelco Dolstra d67fe90375
Merge pull request #6305 from flox/genericClosure_doc
docs: genericClosure
2022-03-24 14:02:58 +01:00
Tom Bereknyei 0736f3651d docs: genericClosure 2022-03-24 08:03:59 -04:00
Eelco Dolstra e4ff430866
Merge pull request #6237 from obsidiansystems/store-path-string-context
Decode string context straight to using StorePaths
2022-03-22 10:29:46 +01:00
John Ericson 4d6a3806d2 Decode string context straight to using StorePaths
I gather decoding happens on demand, so I hope don't think this should
have any perf implications one way or the other.
2022-03-18 15:36:11 +00:00
John Ericson a544ed7684 Generalize DerivationType in preparation for impure derivations 2022-03-18 14:59:56 +00:00
John Ericson 049fae155a Avoid some pointless copying of drvs 2022-03-18 14:59:56 +00:00
John Ericson 8496be7def Use Deferred when building an input-addressed drv
Easier than using dummy path with input addressed.
2022-03-18 14:59:56 +00:00
John Ericson 197feed51d Clean up DerivationOutput, and headers
1. `DerivationOutput` now as the `std::variant` as a base class. And the
   variants are given hierarchical names under `DerivationOutput`.

   In 8e0d0689be @matthewbauer and I
   didn't know a better idiom, and so we made it a field. But this sort
   of "newtype" is anoying for literals downstream.

   Since then we leaned the base class, inherit the constructors trick,
   e.g. used in `DerivedPath`. Switching to use that makes this more
   ergonomic, and consistent.

2. `store-api.hh` and `derivations.hh` are now independent.

   In bcde5456cc I swapped the dependency,
   but I now know it is better to just keep on using incomplete types as
   much as possible for faster compilation and good separation of
   concerns.
2022-03-17 22:35:53 +00:00
Ben Burdette 88a54108eb formatting 2022-03-16 12:09:47 -06:00
Ben Burdette eaecaaa00b more debug_throw coverage of EvalErrors 2022-03-14 11:39:53 -06:00
John Ericson 0948b8e94d Reduce variants for derivation hash modulo
This changes was taken from dynamic derivation (#4628). It` somewhat
undoes the refactors I first did for floating CA derivations, as the
benefit of hindsight + requirements of dynamic derivations made me
reconsider some things.

They aren't to consequential, but I figured they might be good to land
first, before the more profound changes @thufschmitt has in the works.
2022-03-11 21:20:37 +00:00
Robert Hensing ee019d0afc Add EvalState::allowAndSetStorePathString helper
This switches addPath from `printStorePath` to `toRealPath`.
2022-02-28 21:37:49 +01:00
Eelco Dolstra df552ff53e Remove std::string alias (for real this time)
Also use std::string_view in a few more places.
2022-02-25 16:13:02 +01:00
Eelco Dolstra 1ac2664472 Remove std::vector alias 2022-02-21 16:32:34 +01:00
Eelco Dolstra fe9afb65bb Remove std::set alias 2022-02-21 16:28:23 +01:00
Eelco Dolstra afcdc7606c Remove std::list alias 2022-02-21 16:25:12 +01:00
Ben Burdette c9bc3735f6 quit repl from step mode 2022-02-15 09:49:25 -07:00
Ben Burdette e761bf0601 make an 'info' level error on break 2022-02-14 14:04:34 -07:00
Ben Burdette 4cffb130e3 for primops, enter the debugger at the last DebugTrace in the stack 2022-02-11 14:14:25 -07:00
Ben Burdette dbe3fd3735 Merge branch 'master' into debug-step 2022-02-04 15:09:40 -07:00
Ben Burdette 3ddf864e1b print value in break 2022-02-04 14:50:25 -07:00
Eelco Dolstra 4c755c3b3f Merge branch 'issue-3505' of https://github.com/kamadorueda/nix 2022-02-04 00:33:13 +01:00
Ben Burdette 412d58f0bb break() primop; step and go debug commands 2022-02-03 13:15:21 -07:00
Eelco Dolstra cd35bbbeef Merge branch 'more-stringviews' of https://github.com/pennae/nix 2022-02-02 12:38:37 +01:00
Thomas Koch 85b1427662 fix spelling mistakes reported by Debian's lintian tool 2022-01-30 10:51:39 +02:00
Eelco Dolstra 4bf6af7b55 Remove a repeated std::move in a for loop 2022-01-28 15:10:43 +01:00
pennae d439dceb3b optionally return string_view from coerceToString
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.
2022-01-27 22:15:30 +01:00
pennae 41d70a2fc8 return string_views from forceString*
once a string has been forced we already have dynamic storage allocated for it,
so we can easily reuse that storage instead of copying.
2022-01-27 17:15:43 +01:00
regnat fcdc60ed22 Don’t require NIX_PATH entries to be valid paths
It’s totally valid to have entries in `NIX_PATH` that aren’t valid paths
(they can even be arbitrary urls or `channel:<channel-name>`).

Fix #5998 and #5980
2022-01-27 16:26:39 +01:00
Eelco Dolstra 8cbbaf23e8 Allow builtins.{readFile,path} on invalid paths
Stop-gap measure to fix #5975.
2022-01-24 23:02:28 +01:00
Kevin Amado c3896e19d0
forceAttrs: make pos mandatory 2022-01-21 16:32:43 -05:00
Eelco Dolstra 128098040b
Fix exception handling around realisePath()
This no longer worked correctly because 'path' is uninitialised when
an exception occurs, leading to errors like

       … while importing ''

       at /nix/store/rrzz5b1pshvzh1437ac9nkl06br81lkv-source/flake.nix:352:13:

So move the adding of the error context into realisePath().
2022-01-21 13:53:18 +01:00
Eelco Dolstra 4af88a4c91
Merge pull request #5906 from pennae/primops-optimization
optimize primops and utils by caching more and copying less
2022-01-18 19:43:28 +01:00
Eelco Dolstra fc2443a67c
Merge pull request #5812 from pennae/small-perf-improvements
improve parser performance a bit
2022-01-17 19:49:52 +01:00
pennae ad60dfde2a also cache split regexes, not just match regexes
gives about 1% improvement on system eval, a bit less on nix search.

 # before

  nix search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      7.419 s ±  0.045 s    [User: 6.362 s, System: 0.794 s]
    Range (min … max):    7.335 s …  7.517 s    20 runs

  nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
    Time (mean ± σ):      2.921 s ±  0.023 s    [User: 2.626 s, System: 0.210 s]
    Range (min … max):    2.883 s …  2.957 s    20 runs

 # after

  nix search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      7.370 s ±  0.059 s    [User: 6.333 s, System: 0.791 s]
    Range (min … max):    7.286 s …  7.541 s    20 runs

  nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
    Time (mean ± σ):      2.891 s ±  0.033 s    [User: 2.606 s, System: 0.210 s]
    Range (min … max):    2.823 s …  2.958 s    20 runs
2022-01-14 14:04:17 +01:00