Commit graph

673 commits

Author SHA1 Message Date
John Ericson 91adfb8894 Create some type aliases for string Contexts 2022-03-11 22:30:10 +00:00
Eelco Dolstra aee56e0f89 Merge remote-tracking branch 'origin/eval-suggestions' 2022-03-11 12:02:26 +01:00
Eelco Dolstra 31a392dfe2 Merge pull request #5865 from pennae/memory-friendliness
be more memory friendly
2022-03-11 11:52:39 +01:00
pennae c96460f352 force-inline a few much-used functions
these functions are called a whole lot, and they're all comparatively small.
always inlining them gives ~0.7% performance boost on eval.

before:

  Benchmark 1: nix flakes search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      6.935 s ±  0.052 s    [User: 5.852 s, System: 0.853 s]
    Range (min … max):    6.808 s …  7.026 s    20 runs

  Benchmark 2: nix flakes eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
    Time (mean ± σ):     329.8 ms ±   2.7 ms    [User: 299.0 ms, System: 30.8 ms]
    Range (min … max):   326.6 ms … 336.5 ms    20 runs

  Benchmark 3: nix flakes eval --raw --impure --file expr.nix
    Time (mean ± σ):      2.655 s ±  0.038 s    [User: 2.364 s, System: 0.220 s]
    Range (min … max):    2.574 s …  2.737 s    20 runs

after:

  Benchmark 1: nix flakes search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      6.912 s ±  0.036 s    [User: 5.823 s, System: 0.856 s]
    Range (min … max):    6.849 s …  6.980 s    20 runs

  Benchmark 2: nix flakes eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
    Time (mean ± σ):     325.1 ms ±   2.5 ms    [User: 293.2 ms, System: 31.8 ms]
    Range (min … max):   322.2 ms … 332.8 ms    20 runs

  Benchmark 3: nix flakes eval --raw --impure --file expr.nix
    Time (mean ± σ):      2.636 s ±  0.024 s    [User: 2.352 s, System: 0.226 s]
    Range (min … max):    2.574 s …  2.681 s    20 runs
2022-03-08 23:30:18 +01:00
pennae 60ed4e908a cache singleton Envs just like Values
vast majority of envs is this size.

before:

  Benchmark 1: nix flakes search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      6.946 s ±  0.041 s    [User: 5.875 s, System: 0.835 s]
    Range (min … max):    6.834 s …  7.005 s    20 runs

  Benchmark 2: nix flakes eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
    Time (mean ± σ):     330.3 ms ±   2.5 ms    [User: 299.2 ms, System: 30.9 ms]
    Range (min … max):   327.5 ms … 337.7 ms    20 runs

  Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
    Time (mean ± σ):      2.671 s ±  0.035 s    [User: 2.370 s, System: 0.232 s]
    Range (min … max):    2.597 s …  2.749 s    20 runs

after:

  Benchmark 1: nix flakes search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      6.935 s ±  0.052 s    [User: 5.852 s, System: 0.853 s]
    Range (min … max):    6.808 s …  7.026 s    20 runs

  Benchmark 2: nix flakes eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
    Time (mean ± σ):     329.8 ms ±   2.7 ms    [User: 299.0 ms, System: 30.8 ms]
    Range (min … max):   326.6 ms … 336.5 ms    20 runs

  Benchmark 3: nix flakes eval --raw --impure --file expr.nix
    Time (mean ± σ):      2.655 s ±  0.038 s    [User: 2.364 s, System: 0.220 s]
    Range (min … max):    2.574 s …  2.737 s    20 runs
2022-03-08 23:30:18 +01:00
pennae 4b2b0d3a55 remove GC_PTR_STORE_AND_DIRTY
turns out it's only necessary for MANUAL_VDB, which nix doesn't use. omitting
them gives a slight performance improvement on eval.

before:

  Benchmark 1: nix flakes search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      6.988 s ±  0.061 s    [User: 5.935 s, System: 0.845 s]
    Range (min … max):    6.865 s …  7.075 s    20 runs

  Benchmark 2: nix flakes eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
    Time (mean ± σ):     332.6 ms ±   3.9 ms    [User: 299.6 ms, System: 32.9 ms]
    Range (min … max):   328.1 ms … 339.1 ms    20 runs

  Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
    Time (mean ± σ):      2.681 s ±  0.049 s    [User: 2.382 s, System: 0.228 s]
    Range (min … max):    2.607 s …  2.776 s    20 runs

after:

  Benchmark 1: nix flakes search --no-eval-cache --offline ../nixpkgs hello
    Time (mean ± σ):      6.946 s ±  0.041 s    [User: 5.875 s, System: 0.835 s]
    Range (min … max):    6.834 s …  7.005 s    20 runs

  Benchmark 2: nix flakes eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
    Time (mean ± σ):     330.3 ms ±   2.5 ms    [User: 299.2 ms, System: 30.9 ms]
    Range (min … max):   327.5 ms … 337.7 ms    20 runs

  Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
    Time (mean ± σ):      2.671 s ±  0.035 s    [User: 2.370 s, System: 0.232 s]
    Range (min … max):    2.597 s …  2.749 s    20 runs
2022-03-08 23:30:18 +01:00
regnat f6078e474d Also display some suggestions for invalid formal arguments
```console
$ nix eval --expr '({ foo ? 1 }: foo) { fob = 2; }'
error: anonymous function at (string):1:2 called with unexpected argument 'fob'

       at «string»:1:1:

            1| ({ foo ? 1 }: foo) { fob = 2; }
             | ^
       Did you mean foo?
```

Not that because Nix will first check for _missing_ arguments before
checking for extra arguments, `({ foo }: foo) { fob = 1; }` will
complain about the missing `foo` argument (rather than extra `fob`) and
so won’t display a suggestion.
2022-03-08 16:40:22 +01:00
regnat 33b7514035 Try and make the darwin build happy 2022-03-08 16:07:17 +01:00
regnat 0c6e46e349 Add some suggestions to the evaluator
Make the evaluator show some suggestions when trying to access an
invalid field from an attrset.

```console
$ nix eval --expr '{ foo = 1; }.foa'
error: attribute 'foa' missing

       at «string»:1:1:

            1| { foo = 1; }.foa
             | ^
       Did you mean foo?
```
2022-03-08 06:21:45 +01:00
Robert Hensing da260f579d dupStringWithLen -> makeImmutableString
Refactor the `size == 0` logic into a new helper function that
replaces dupStringWithLen.
The name had to change, because unlike a `dup`-function, it does
not always allocate a new string.
2022-03-07 16:09:12 +01:00
Robert Hensing bbf55383e7 Value::mkPath: Avoid potential crash from null string_view 2022-03-07 16:09:12 +01:00
Robert Hensing 1b978596b5 Value::mkString: Avoid crash from null string_view 2022-03-07 16:09:12 +01:00
Eelco Dolstra e9c04c3351 Be more aggressive in hiding repeated values
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.
2022-03-03 13:33:34 +01:00
Eelco Dolstra ecff9d969a printValue(): Don't show repeated values
Fixes #6157.
2022-03-03 13:18:23 +01:00
Eelco Dolstra b55d79728c Add EvalState::coerceToStorePath() helper
This is useful whenever we want to evaluate something to a store path
(e.g. in get-drvs.cc).

Extracted from the lazy-trees branch (where we can require that a
store path must come from a store source tree accessor).
2022-03-02 23:58:58 +01:00
Eelco Dolstra d974d2ad59 fetch{url,Tarball}: Remove 'narHash' attribute
This was introduced in #6174. However fetch{url,Tarball} are legacy
and we shouldn't have an undocumented attribute that does the same
thing as one that already exists ('sha256').
2022-03-01 11:30:26 +01:00
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
Ben Burdette 3d94d3ba91 Expr refs instead of pointers 2022-02-15 15:46:45 -07:00
Ben Burdette c9bc3735f6 quit repl from step mode 2022-02-15 09:49:25 -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 3ff5ac3586 update the eval-inline throw fns 2022-02-10 16:01:49 -07:00
Ben Burdette bc67cb5ad1 remove fakeEnv stuff and instead use last context from the stack 2022-02-10 15:05:38 -07:00
Ben Burdette 195db83148 a few merge fixes 2022-02-04 17:35:56 -07:00
Ben Burdette dbe3fd3735 Merge branch 'master' into debug-step 2022-02-04 15:09:40 -07:00
Eelco Dolstra bd383d1b6f Make most calls to determinePos() lazy 2022-02-04 00:33:21 +01:00
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 17e3f353df Merge branch 'parser-improvements' of https://github.com/pennae/nix 2022-02-02 12:45:44 +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
pennae fd5aa6ee3e allocate a GC root value for the Value cache pointer
keeping it as a simple data member means it won't be scanned by the GC, so
eventually the GC will collect a cache that is still referenced (resulting in
use-after-free of cache elements).

fixes #5962
2022-01-22 21:19:56 +01:00
Kevin Amado 50efc5499a
determinePos: remove from critical path 2022-01-21 16:32:43 -05:00
Kevin Amado c3896e19d0
forceAttrs: make pos mandatory 2022-01-21 16:32:43 -05:00
Kevin Amado 49b0bb0206
forceValue: make pos mandatory
- 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
2022-01-21 16:32:43 -05:00
pennae 7d4cc5515c defer formals duplicate check for incresed efficiency all round
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
2022-01-19 17:07:29 +01:00
pennae 1bebb1095a cache more often-used symbols for primops
there's a few symbols in primops we can create once and pick them out of
EvalState afterwards instead of creating them every time we need them. this
gives almost 1% speedup to an uncached nix search.
2022-01-13 13:58:33 +01:00
pennae 5838354d34 optimize ExprConcatStrings::eval
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
2022-01-12 10:07:21 +01:00
Ben Burdette a963674d88 optinoal error; compiles 2022-01-08 11:03:48 -07:00
Ben Burdette c51b527c28 add env to DebugTrace 2022-01-07 16:37:44 -07:00
Ben Burdette bf8a065be0 add colors; remove headings 2022-01-05 12:28:31 -07:00
Ben Burdette a4d8a799b7 tidy up debugtraces 2022-01-05 12:21:18 -07:00
Eelco Dolstra 2b4c944823 Remove EvalState::mkAttrs() 2022-01-04 20:29:17 +01:00
Eelco Dolstra 17daec0b83 Move empty attrset optimisation 2022-01-04 19:23:11 +01:00
Eelco Dolstra ed93aec3c3 Remove non-method mkPath() 2022-01-04 18:45:16 +01:00
Eelco Dolstra 263a8d293c Remove non-method mk<X> functions 2022-01-04 18:40:39 +01:00
Eelco Dolstra cc08364315 Remove non-method mkString() 2022-01-04 18:24:42 +01:00
Eelco Dolstra 6d9a6d2cc3 Ensure that attrsets are sorted
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.
2022-01-04 18:00:33 +01:00
Ben Burdette 1b6b33d43d filter out underscore names 2022-01-03 18:29:43 -07:00
Ben Burdette a47de1ac37 Merge branch 'master' into debug-exploratory-PR 2022-01-03 16:08:28 -07:00
Ben Burdette 5954cbf3e9 more cleanup 2021-12-27 18:29:55 -07:00
Ben Burdette 4610e02d04 remove debug code 2021-12-27 18:12:46 -07:00
Ben Burdette 9760fa8661 add DebugTrace for the current error 2021-12-27 17:35:27 -07:00
Ben Burdette 6801a423fc :d env 2021-12-27 16:28:45 -07:00
Ben Burdette ff82ba98b4 don't add builtins to extras, initEnv() in regular repl 2021-12-27 14:06:04 -07:00
Ben Burdette d0d5890445 don't add underscore names to extras 2021-12-27 13:47:35 -07:00
Ben Burdette e5eebda194 DebugTrace 2021-12-23 13:36:39 -07:00
Ben Burdette deb1fd66e8 makeDebugTraceStacker 2021-12-23 09:08:41 -07:00
Ben Burdette 1bda6a01e1 indenting 2021-12-23 08:14:17 -07:00
Ben Burdette bc20e54e00 stack traces basically working 2021-12-22 19:40:08 -07:00
Ben Burdette b4a59a5eec DebugStackTracker class in one place 2021-12-22 15:38:49 -07:00
pennae 09b245690a bulk-allocate Value instances in the evaluator
calling GC_malloc for each value is significantly more expensive than
allocating a bunch of values at once with GC_malloc_many. "a bunch" here
is a GC block size, ie 16KiB or less.

this gives a 1.5% performance boost when evaluating our nixos system.

tested with

nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'

 # on master

  Time (mean ± σ):      3.335 s ±  0.007 s    [User: 2.774 s, System: 0.293 s]
  Range (min … max):    3.315 s …  3.347 s    50 runs

 # with this change

  Time (mean ± σ):      3.288 s ±  0.006 s    [User: 2.728 s, System: 0.292 s]
  Range (min … max):    3.274 s …  3.307 s    50 runs
2021-12-20 23:01:28 +01:00
Eelco Dolstra cc6406cc59 Merge branch 'better-interpolation-error-location' of https://github.com/greedy/nix 2021-12-13 19:20:48 +01:00
Ben Burdette e82aec4efc fix merge issues 2021-11-30 14:15:02 -07:00
Eelco Dolstra 6f46434f32
Merge pull request #5648 from edolstra/list-iter
Support range-based for loop over list values
2021-11-25 17:13:25 +01:00
Ben Burdette 64c4ba8f66 Merge branch 'master' into debug-merge 2021-11-25 08:53:59 -07:00
Eelco Dolstra b6c8e57056 Support range-based for loop over list values 2021-11-25 16:31:39 +01:00
Ben Burdette 69e26c5c4b more cleanup 2021-11-25 08:23:07 -07:00
regnat c47027f3a1 Fix the error when accessing a forbidden path in pure eval
If we’re in pure eval mode, then tell that in the error message rather
than (wrongly) speaking about restricted mode.

Fix https://github.com/NixOS/nix/issues/5611
2021-11-25 14:48:01 +01:00
Tom Bereknyei 4318ba2ec5 add real path to allowedPaths 2021-11-20 00:25:36 -05:00
Eelco Dolstra d7bae52b9d Call functors with both arguments at once
This is not really useful on its own, but it does recover the
'infinite recursion' error message for '{ __functor = x: x; } 1', and
is more efficient in conjunction with #3718.

Fixes #5515.
2021-11-16 22:34:17 +01:00
Eelco Dolstra e41cf8511f Don't hang when calling an attrset
Fixes #5565.
2021-11-16 17:44:19 +01:00
Ben Burdette 7e2a3db4eb cleanup 2021-11-09 13:14:49 -07:00
Ben Burdette 885f819922 remove dead code 2021-11-09 11:20:14 -07:00
Eelco Dolstra 40925337a9 Remove maxPrimOpArity 2021-11-04 15:04:07 +01:00
Eelco Dolstra acd6bddec7 Fix derivation primop 2021-11-04 15:04:00 +01:00
Eelco Dolstra bcf4780006 Add level / displacement types 2021-11-04 15:03:45 +01:00
Eelco Dolstra 81e7c40264 Optimize primop calls
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.
2021-11-04 15:03:40 +01:00
Eelco Dolstra ab35cbd675 StaticEnv: Use std::vector instead of std::map 2021-11-04 15:03:34 +01:00
regnat af99941279 Make experimental-features a proper type
Rather than having them plain strings scattered through the whole
codebase, create an enum containing all the known experimental features.

This means that
- Nix can now `warn` when an unkwown experimental feature is passed
  (making it much nicer to spot typos and spot deprecated features)
- It’s now easy to remove a feature altogether (once the feature isn’t
  experimental anymore or is dropped) by just removing the field for the
  enum and letting the compiler point us to all the now invalid usages
  of it.
2021-10-26 07:02:31 +02:00
Ben Burdette fb8377547b more code cleanup 2021-10-22 14:49:58 -06:00
Ben Burdette 71da988d47 more debug removal 2021-10-22 14:34:50 -06:00
Ben Burdette e54f17eb46 remove more debug code 2021-10-22 14:27:04 -06:00
Ben Burdette cbc2f0fe31 remove dead code 2021-10-22 14:02:47 -06:00
Ben Burdette 427fb8d158 comment out debugs 2021-10-11 16:48:10 -06:00
Ben Burdette 98eb13691a print staticenv bindings 2021-10-11 16:32:43 -06:00
Ben Burdette 2ee1fa4afd add nullable Expr argument 2021-10-11 14:42:29 -06:00
Eelco Dolstra d39692e6b3 Make builtins.{path,filterSource} work with chroot stores 2021-10-07 14:22:39 +02:00
Eelco Dolstra 972405edf5 Allow access to path copied to the store
Fixes https://github.com/NixOS/nix/pull/5163#issuecomment-931733912.
2021-10-07 12:15:22 +02:00
Eelco Dolstra cfaad7168e Refactoring: Add allowPath() method 2021-10-07 12:11:00 +02:00
Andreas Rammhold cae41eebff libexpr: remove matchAttrs boolean from ExprLambda
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.
2021-10-06 17:24:06 +02:00
Ben Burdette aad27143c6 storing staticenv bindings 2021-10-02 13:47:36 -06:00
Maximilian Bosch 2b02ce0e48
libexpr: throw a more helpful eval-error if a builtin is not available due to a missing feature-flag
I found it somewhat confusing to have an error like

    error: attribute 'getFlake' missing

if the required experimental-feature (`flakes`) is not enabled. Instead,
I'd expect Nix to throw an error just like it's the case when using e.g. `nix
flake` without `flakes` being enabled.

With this change, the error looks like this:

    $ nix-instantiate -E 'builtins.getFlake "nixpkgs"'
    error: Cannot call 'builtins.getFlake' because experimental Nix feature 'flakes' is disabled. You can enable it via '--extra-experimental-features flakes'.

           at «string»:1:1:

                1| builtins.getFlake "nixpkgs"
                 | ^

I didn't use `settings.requireExperimentalFeature` here on purpose
because this doesn't contain a position. Also, it doesn't seem as if we
need to catch the error and check for the missing feature here since
this already happens at evaluation time.
2021-09-29 11:57:15 +02:00
Geoff Reedy 9d67332e4b Better eval error locations for interpolation and +
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
2021-09-22 20:57:34 -06:00
Ben Burdette c07edb1932 staticenv should be With 2021-09-22 18:14:57 -06:00
Ben Burdette cd8c232b55 add cout debugging 2021-09-15 16:16:53 -06:00
Ben Burdette 21071bfdeb shared_ptr for StaticEnv 2021-09-14 10:49:22 -06:00
Ben Burdette 176911102c printEnvPosChain 2021-09-13 11:57:25 -06:00
Eelco Dolstra 49a932fb18 nix --help: Display help using lowdown instead of man
Fixes #4476.
Fixes #5231.
2021-09-13 14:45:21 +02:00
Eelco Dolstra 7ee639f9db
Merge pull request #5066 from Radvendii/master
add antiquotations to paths
2021-09-01 12:55:04 +02:00