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421 commits

Author SHA1 Message Date
Qyriad a3361557e3 libexpr: refactor gc-agnostic helpers into one place
Change-Id: Icc4b367e4f670d47256f62a3a002cd248a5c2d3b
2024-07-20 20:20:01 +00:00
Qyriad b9f91ec3c5 mildly cleanup libexpr/eval.hh
Change-Id: I40d01a8f8b7fb101279c6f88ebdf1f0969d9d7f0
2024-07-04 17:43:03 -06:00
Eelco Dolstra fb7d315411 Merge pull request #10570 from layus/shared_caches
Share evaluation caches across installables

Before:

$ rm -rf ~/.cache/nix && time -f '%E' nix build --dry-run \
  'nixpkgs#hello' \
  'nixpkgs#clang' \
  'nixpkgs#cargo' \
  'nixpkgs#rustup' \
  'nixpkgs#bear' \
  'nixpkgs#firefox' \
  'nixpkgs#git-revise' \
  'nixpkgs#hyperfine' \
  'nixpkgs#curlie' \
  'nixpkgs#xz' \
  'nixpkgs#ripgrep'
0:03.61

After:

$ rm -rf ~/.cache/nix && time -f '%E' nix build --dry-run \
  'nixpkgs#hello' \
  'nixpkgs#clang' \
  'nixpkgs#cargo' \
  'nixpkgs#rustup' \
  'nixpkgs#bear' \
  'nixpkgs#firefox' \
  'nixpkgs#git-revise' \
  'nixpkgs#hyperfine' \
  'nixpkgs#curlie' \
  'nixpkgs#xz' \
  'nixpkgs#ripgrep'
0:01.46

This could probably use a more proper benchmark...

Fixes #313

(cherry picked from commit de51e5c335865e3e0a8cccd283fec1a52cce243f)
Change-Id: I9350bebd462b6af12c51db5bf432321abfe84a16
2024-06-19 18:39:11 +00:00
eldritch horrors ad5366c2ad libexpr: pass Exprs as references, not pointers
almost all places where Exprs are passed as pointers expect the pointers
to be non-null. pass them as references to encode this constraint in the
type system as well (and also communicate that Exprs must not be freed).

Change-Id: Ia98f166fec3c23151f906e13acb4a0954a5980a2
2024-06-17 19:46:44 +00:00
Yorick 194654c96f primops: change to std::function, allowing the passing of user data
(cherry picked from commit 48aa57549d514432d6621c1e29f051951eca2d7f)
Change-Id: Ib7d5c6514031ceb6c42ac44588be6b0c1c3c225b
2024-05-16 13:01:40 +00:00
Théophane Hufschmitt 6c29016a09 Merge pull request #9920 from 9999years/forbid-nested-debuggers
Forbid nested debuggers

(cherry picked from commit e164b39ee90fd655dbb7f479fdd4fbe38cc883bd)
Change-Id: Iff62f40fd251116516a63e2d3f9fb5b21480b16d
2024-03-31 17:28:25 +00:00
eldritch horrors a9b813cc3b Merge pull request #10066 from 9999years/print-all-frames
Do not skip any stack frames when `--show-trace` is given

(cherry picked from commit 0b47783d0a879875d558f0b56e49584f25ceb2d0)
Change-Id: Ia0f18266dbcf97543110110c655c219c7a3e3270
2024-03-09 10:17:26 -07:00
eldritch horrors 992d99592f :quit in the debugger should quit the whole program
(cherry picked from commit 2a8fe9a93837733e9dd9ed5c078734a35b203e14)
Change-Id: I71dadfef6b24d9272b206e9e2c408040559d8a1c
2024-03-09 10:17:26 -07:00
eldritch horrors b221a14f0a Merge pull request #9925 from 9999years/fmt-cleanup
Cleanup `fmt.hh`

(cherry picked from commit 47a1dbb4b8e7913cbb9b4d604728b912e76e4ca0)
Change-Id: Id076a45cb39652f437fe3f8bda10c310a9894777
2024-03-09 07:00:13 -07:00
eldritch horrors 3d9c7fc1e7 Add comment
(cherry picked from commit 9723f533d85133fa3c4d9421a58c7765cb61e733)
Change-Id: Idd729febc0bb8c7c8db72a0fae73b680f66767f4
2024-03-09 04:47:05 -07:00
eldritch horrors 08252967a8 libexpr: Support structured error classes
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
2024-03-09 04:47:05 -07:00
eldritch horrors f7b2476415 don't repeatedly look up ast internal symbols
these symbols are used a *lot*, so it makes sense to cache them. this
mostly increases clarity of the code (however clear one may wish to call
the parser desugaring here), but it also provides a small performance
benefit.

(cherry picked from commit 09a1128d9e2ff0ae6176784938047350d6f8a782)
Change-Id: I73d9f66be4555168e048cb2d542277251580c2d1
2024-03-09 00:25:54 -07:00
eldritch horrors 512c1f05c3 Unify and refactor value printing
Previously, there were two mostly-identical value printers -- one in
`libexpr/eval.cc` (which didn't force values) and one in
`libcmd/repl.cc` (which did force values and also printed ANSI color
codes).

This PR unifies both of these printers into `print.cc` and provides a
`PrintOptions` struct for controlling the output, which allows for
toggling whether values are forced, whether repeated values are tracked,
and whether ANSI color codes are displayed.

Additionally, `PrintOptions` allows tuning the maximum number of
attributes, list items, and bytes in a string that will be displayed;
this makes it ideal for contexts where printing too much output (e.g.
all of Nixpkgs) is distracting. (As requested by @roberth in
https://github.com/NixOS/nix/pull/9554#issuecomment-1845095735)

Please read the tests for example output.

Future work:
- It would be nice to provide this function as a builtin, perhaps
  `builtins.toStringDebug` -- a printing function that never fails would
  be useful when debugging Nix code.
- It would be nice to support customizing `PrintOptions` members on the
  command line, e.g. `--option to-string-max-attrs 1000`.

(cherry picked from commit 0fa08b451682fb3311fe58112ff05c4fe5bee3a4, )

===

Restore ambiguous value printer for `nix-instantiate`

The Nix team has requested that this output format remain unchanged.
I've added a warning to the man page explaining that `nix-instantiate
--eval` output will not parse correctly in many situations.

(cherry picked from commit df84dd4d8dd3fd6381ac2ca3064432ab31a16b79)

Change-Id: I7cca6b4b53cd0642f2d49af657d5676a8554c9f8
2024-03-09 03:50:06 +01:00
eldritch horrors 89e99d94e4 Merge pull request #9634 from 9999years/combine-abstract-pos-and-pos
Combine `AbstractPos`, `PosAdapter`, and `Pos`

(cherry picked from commit 113499d16fc87d53b73fb62fe6242154909756ed)

===

this is a bit cursed because originally it was based on InputAccessor
code that we don't have and moved/patched features we likewise don't
have (fetchToStore caching, all the individual accessors,
ContentAddressMethod). the commit is adjusted accordingly to
match (remove caching, ignore accessors, use FileIngestionMethod).

note that `state.rootPath . CanonPath == abs` and
computeStorePathForPath works relative to cwd, so the slight rewrite in
the moved fetchToStore is legal.

Change-Id: I05fd340c273f0bcc8ffabfebdc4a88b98083bce5
2024-03-05 23:46:18 -07:00
eldritch horrors 137673de56 Merge pull request #9681 from edolstra/eval-optimisations
Optimize empty list constants

(cherry picked from commit 315aade89d00c692715e5953c36a1b7d6528b703)
Change-Id: I0f28ef8a27ccedc45acf44243eec9dc35b733300
2024-03-04 07:39:12 +01:00
eldritch horrors 6b279cd10e Merge pull request #9658 from pennae/env-diet
reduce the size of Env by one pointer

(cherry picked from commit 83f5622545a2fc31eb7e7d5105f64ed6dd3058b3)
Change-Id: I5636290526d0165cfc61aee1e7a5b94db4a26cef
2024-03-04 07:37:45 +01:00
eldritch horrors 96f1a404d0 Merge pull request #9617 from 9999years/stack-overflow-segfault
Fix segfault on infinite recursion in some cases

(cherry picked from commit bf1b294bd81ca76c5ec9fe3ecd52196bf52a8300)
Change-Id: Id137541426ec8536567835953fccf986a3aebf16
2024-03-04 07:35:20 +01:00
eldritch horrors dd180911d8 Merge pull request #9582 from pennae/misc-opts
a packet of small optimizations

(cherry picked from commit ee439734e924eb337a869ff2e48aff8b989198bc)
Change-Id: I125d870710750a32a0dece48f39a3e9132b0d023
2024-03-04 07:32:31 +01:00
eldritch horrors 5e182235cb Merge pull request #7348 from thufschmitt/dont-use-vlas
Remove the usage of VLAs in the code

(cherry picked from commit ac4431e9d016e62fb5dc9ae36833bd0c6cdadeec)
Change-Id: Ifbf5fbfc2e27122362a2aaea4b62c7cf3ca46b1a
2024-03-04 05:51:23 +01:00
eldritch horrors 6feba52008 Merge pull request #8895 from hercules-ci/gc-before-stats
eval: Run a full GC before printing stats

(cherry picked from commit aeea49609be014b1928c95b7ec28dbedeb4f032a)
Change-Id: I47a23d3a7a47ea61d9a2b5727b638f879f3aaf1e
2024-03-04 04:36:47 +01:00
Eelco Dolstra bef68e53b9 Fix symlink handling
This restores the symlink handling behaviour prior to
94812cca98.

Fixes #9298.

(cherry picked from commit 31ebc6028b3682969d86a7b39ae87131c41cc604)
2024-01-21 20:53:30 +00:00
John Ericson fe71faa920 Delete EvalState::addToSearchPath
This function is now trivial enough that it doesn't need to exist.

`EvalState` can still be initialized with a custom search path, but we
don't have a need to mutate the search path after it has been
constructed, and I don't see why we would need to in the future.

Fixes #8229
2023-08-18 14:04:33 -04:00
John Ericson e7c39ff00b Rework evaluator SingleDerivedPath infra
`EvalState::mkSingleDerivedPathString` previously contained its own
inverse (printing, rather than parsing) in order to validate what was
parsed. Now that is pulled out into its own separate function:
`EvalState::coerceToSingleDerivedPath`.

In additional that pulled out logic is deduplicated with
`EvalState::mkOutputString` via `EvalState::mkOutputStringRaw`, which is
itself deduplicated (and generalized) with
`DownstreamPlaceholder::mkOutputStringRaw`.

All these changes make the unit tests simpler.

(We would ideally write more unit tests for `mkSingleDerivedPathString`
`coerceToSingleDerivedPath` directly, but we cannot yet do that because
the IO in reading the store path won't work when the dummy store cannot
hold anything. Someday we'll have a proper in-memory store which will
work for this.)

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-08-14 08:44:50 -04:00
John Ericson a04720e68c Rename optOutputPath to optStaticOutputPath
This choice of variable name makes it more clear what is going on.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-08-14 08:44:48 -04:00
John Ericson 60b7121d2c Make the Derived Path family of types inductive for dynamic derivations
We want to be able to write down `foo.drv^bar.drv^baz`:
`foo.drv^bar.drv` is the dynamic derivation (since it is itself a
derivation output, `bar.drv` from `foo.drv`).

To that end, we create `Single{Derivation,BuiltPath}` types, that are
very similar except instead of having multiple outputs (in a set or
map), they have a single one. This is for everything to the left of the
rightmost `^`.

`NixStringContextElem` has an analogous change, and now can reuse
`SingleDerivedPath` at the top level. In fact, if we ever get rid of
`DrvDeep`, `NixStringContextElem` could be replaced with
`SingleDerivedPath` entirely!

Important note: some JSON formats have changed.

We already can *produce* dynamic derivations, but we can't refer to them
directly. Today, we can merely express building or example at the top
imperatively over time by building `foo.drv^bar.drv`, and then with a
second nix invocation doing `<result-from-first>^baz`, but this is not
declarative. The ethos of Nix of being able to write down the full plan
everything you want to do, and then execute than plan with a single
command, and for that we need the new inductive form of these types.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-08-10 00:08:32 -04:00
Théophane Hufschmitt 5df0f1755f
Merge pull request #8692 from obsidiansystems/add-another-xp-check
Feature gate `DownstreamPlaceholder::unknownCaOutput`
2023-08-07 13:11:44 +02:00
John Ericson 1570e80219 Move evaluator settings (type and global) to separate file/header 2023-07-31 10:14:15 -04:00
Valentin Gagarin 0e4f6dfcf7 revert anchor prefix for builtin constants
the original change broke many pre-existing anchor links.

also change formatting of the constants listing slightly:
- the type should not be part of the anchor
- add highlight to the "impure only" note
2023-07-20 10:27:38 +02:00
John Ericson caabc4f648 Feature gate DownstreamPlaceholder::unknownCaOutput
This is a part of CA derivations that we forgot to put behind the
experimental feature.

This was caught by @fricklerhandwerk in
https://github.com/NixOS/nix/pull/8369#discussion_r1258133719
2023-07-13 07:56:33 -04:00
John Ericson be518e73ae Clean up SearchPath
- Better types

- Own header / C++ file pair

- Test factored out methods

- Pass parsed thing around more than strings

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-07-09 23:22:22 -04:00
John Ericson 87dcd09047 Clean up resolveSearchPathElem
We should use `std::optional<std::string>` not `std::pair<bool,
std::string>` for an optional string.
2023-07-09 23:13:30 -04:00
John Ericson 22b278e011 Automatically document builtin constants
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>
2023-06-27 09:37:54 -04:00
John Ericson e8067daf09 Generialize showType 2023-06-27 09:11:42 -04:00
John Ericson 484290a9e0 Use a struct not std::pair for SearchPathElem
I got very confused trying to keep all the `first` and `second` straight
reading the code, *especially* as there is also another `(boolean,
string)` pair type also being used.

Named fields is much better.

There are other cleanups that we can do (for example, the existing
TODO), but we can do them later. Doing them now would just make this
harder to review.
2023-06-23 12:01:10 -04:00
Adam Joseph 6b06e97bde src/libexpr/eval.hh: add link for allowed-uris option
This commit adds a link to the documentation for `--option
allowed-uris` where that option is mentioned while describing
`restrict-eval`.
2023-06-18 23:36:32 -04:00
Adam Joseph 098fbf6273 src/libexpr/eval.hh: fix typo
The option name is `allowed-uris`, not `allowed-uri`.
2023-06-14 21:47:58 -07:00
Valentin Gagarin 738c0d5064
Merge pull request #8318 from fricklerhandwerk/doc-currentTime
document `builtins.currentTime`
2023-05-31 03:15:54 +02:00
John Ericson b9e5ce4a27 Upgrade downstreamPlaceholder to a type with methods
This gets us ready for dynamic derivation dependencies (part of RFC 92).
2023-05-17 17:41:16 -04:00
Valentin Gagarin 6a5a8f51bb add cross-references to pure evaluation mode
use consistent wording everywhere.
add some details on the configuration option documentation.
2023-05-17 15:01:54 +02:00
John Ericson 5a23b80b0a Create EvalState::coerceToDerivedPath
This gives us some round trips to test.

`EvalState::coerceToDerivedPathUnchecked` is a factored out helper just
for unit testing.
2023-05-15 09:03:37 -04:00
John Ericson 8e1a990268 Expose mkOutputString as method of EvalState 2023-05-15 09:03:37 -04:00
Eelco Dolstra 01232358ff Merge remote-tracking branch 'origin/master' into source-path 2023-04-24 13:20:36 +02:00
John Ericson 85f0cdc370 Use std::set<StringContextElem> not PathSet for string contexts
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>
2023-04-21 01:05:49 -04:00
Robert Hensing cb2615cf47 Merge remote-tracking branch 'upstream/master' into source-path 2023-04-17 11:41:50 +02:00
John Ericson 0746951be1
Finish converting existing comments for internal API docs (#8146)
* 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.
2023-04-07 13:55:28 +00:00
Eelco Dolstra a9759407e5 Origin: Use SourcePath 2023-04-06 15:25:06 +02:00
Eelco Dolstra 94812cca98 Backport SourcePath from the lazy-trees branch
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.)
2023-04-06 13:15:50 +02:00
John Ericson f4ab297b31 Ensure all headers have #pragma once and are in API docs
`///@file` makes them show up in the internal API dos. A tiny few were
missing `#pragma once`.
2023-03-31 23:19:44 -04:00
Eelco Dolstra dd93c12c6a Revert "getDefaultNixPath: actually respect {restrict,pure}-eval"
This reverts commit 1cba5984a6.
2023-02-27 15:11:36 +01:00
Eelco Dolstra e928c72cf9 Revert "Document default nix-path value"
This reverts commit dba9173a1d.
2023-02-27 14:16:49 +01:00