This commit adds a new helper template function to gc-alloc.hh (which is
probably where you want to look at first, O great reviewer [custom file
ordering in review diffs when]), which uses a type argument to determine
the size to allocate, rather than making the caller use sizeof().
Change-Id: Ib5d138d91a28bdda304a80db24ea9fb08669ad22
The purpose of this function has little to do with immutability. Value's
strings are never mutated, and the point of this function is to
singleton empty strings.
Change-Id: Ifd41dd952409d54e4d3de9ab59064e6928b0e480
* changes:
Fixup a bunch of references to nixos.org manuals
Add release notes for removing overflow from Nix language
expr: fix a compiler warning about different signs in comparison
When the configured maximum depth has been reached, attribute sets and lists
are printed with ellipsis to indicate the elision of nested items. Previously,
this happened even in case the structure being printed is empty, so that such
items do not in fact exist. This is confusing, so stop doing it.
Change-Id: I0016970dad3e42625e085dc896e6f476b21226c9
The repeated value detection logic exists so that the occurrence of large
common substructures does not fill up the screen or the computer's memory.
However, empty attribute sets and derivations (when their detection is enabled)
are always cheap to print, and in practice I have observed them to make up a
significant majority of the cases where I was annoyed by the repeated value
detection kicking in. Furthermore, `nix-instantiate --eval` already disables
this logic for empty attribute sets, and empty lists are already exempted
everywhere. For these reasons, always print empty attribute sets and
derivations as what they are.
Change-Id: I5dac8e7739f9d726b76fd0521ec46f38af94463f
When pretty-printing is enabled, previously an unforced thunk would trigger
indentation, even when it subsequently does not evaluate to a nested structure.
The resulting output looked inconsistent, and furthermore pretty-printing was
not idempotent (since pretty-printing the same value again, which is now fully
evaluated, will not trigger indentation).
When strict evaluation is enabled, force the item before inspecting its type,
so that it is properly known whether it contains a nested structure.
Furthermore, there is no need to cause indentation for unforced thunks, since
the very next operation will be printing them as `«thunk»`.
This is mostly a port of https://github.com/NixOS/nix/pull/11100 , but we only
force the item when it's going to be forced anyway due to strict
pretty-printing, and a new test was written since the REPL testing framework in
Lix is different.
Co-Authored-By: Robert Hensing <robert@roberthensing.nl>
Change-Id: Ib7560fe531d09e05ca6b2037a523fe21a26d9d58
This also bans various sneaking of negative numbers from the language
into unsuspecting builtins as was exposed while auditing the
consequences of changing the Nix language integer type to a newtype.
It's unlikely that this change comprehensively ensures correctness when
passing integers out of the Nix language and we should probably add a
checked-narrowing function or something similar, but that's out of scope
for the immediate change.
During the development of this I found a few fun facts about the
language:
- You could overflow integers by converting from unsigned JSON values.
- You could overflow unsigned integers by converting negative numbers
into them when going into Nix config, into fetchTree, and into flake
inputs.
The flake inputs and Nix config cannot actually be tested properly
since they both ban thunks, however, we put in checks anyway because
it's possible these could somehow be used to do such shenanigans some
other way.
Note that Lix has banned Nix language integer overflows since the very
first public beta, but threw a SIGILL about them because we run with
-fsanitize=signed-overflow -fsanitize-undefined-trap-on-error in
production builds. Since the Nix language uses signed integers, overflow
was simply undefined behaviour, and since we defined that to trap, it
did.
Trapping on it was a bad UX, but we didn't even entirely notice
that we had done this at all until it was reported as a bug a couple of
months later (which is, to be fair, that flag working as intended), and
it's got enough production time that, aside from code that is IMHO buggy
(and which is, in any case, not in nixpkgs) such as
lix-project/lix#445, we don't think
anyone doing anything reasonable actually depends on wrapping overflow.
Even for weird use cases such as doing funny bit crimes, it doesn't make
sense IMO to have wrapping behaviour, since two's complement arithmetic
overflow behaviour is so *aggressively* not what you want for *any* kind
of mathematics/algorithms. The Nix language exists for package
management, a domain where bit crimes are already only dubiously in
scope to begin with, and it makes a lot more sense for that domain for
the integers to never lose precision, either by throwing errors if they
would, or by being arbitrary-precision.
This change will be ported to CppNix as well, to maintain language
consistency.
Fixes: lix-project/lix#423
Change-Id: I51f253840c4af2ea5422b8a420aa5fafbf8fae75
The actual motive here is the avoidance of integer overflow if we were
to make these use checked NixInts and retain the subtraction.
However, the actual *intent* of this code is a three-way comparison,
which can be done with operator<=>, so we should just do *that* instead.
Change-Id: I7f9a7da1f3176424b528af6d1b4f1591e4ab26bf
DrvInfo's query methods all use mutable fields to cache, but like.
that's basically the entire interface for DrvInfo. Not only that, but
these formerly-const-marked functions can even throw due to eval errors!
Changing this only required removing some `const` markers in nix-env,
and changing a single inline `queryInstalled()` call to be an lvalue
instead.
Change-Id: I796807118f3b35b0e93668b5e28210d9e521b2ae
Turns errors like this:
let
throwMsg = a: throw (a + " invalid bar");
in throwMsg "bullshit"
error:
… from call site
at «string»:3:4:
2| throwMsg = a: throw (a + " invalid bar");
3| in throwMsg "bullshit"
| ^
… while calling 'throwMsg'
at «string»:2:14:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
… while calling the 'throw' builtin
at «string»:2:17:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
error: bullshit invalid bar
into errors like this:
let
throwMsg = a: throw (a + " invalid bar");
in throwMsg "bullshit"
error:
… from call site
at «string»:3:4:
2| throwMsg = a: throw (a + " invalid bar");
3| in throwMsg "bullshit"
| ^
… while calling 'throwMsg'
at «string»:2:14:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
… caused by explicit throw
at «string»:2:17:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
error: bullshit invalid bar
Change-Id: I593688928ece20f97999d1bf03b2b46d9ac338cb
Turns errors like:
let
somepkg.src = throw "invalid foobar";
in somepkg.src.meta
error:
… while evaluating the attribute 'src.meta'
at «string»:2:3:
1| let
2| somepkg.src = throw "invalid foobar";
| ^
3| in somepkg.src.meta
… while calling the 'throw' builtin
at «string»:2:17:
1| let
2| somepkg.src = throw "invalid foobar";
| ^
3| in somepkg.src.meta
error: invalid foobar
into errors like:
let
somepkg.src = throw "invalid foobar";
in somepkg.src.meta
error:
… while evaluating the attribute 'src.meta'
at «string»:2:3:
1| let
2| somepkg.src = throw "invalid foobar";
| ^
3| in somepkg.src.meta
… while evaluating 'somepkg.src' to select 'meta' on it
at «string»:3:4:
2| somepkg.src = throw "invalid foobar";
3| in somepkg.src.meta
| ^
… while calling the 'throw' builtin
at «string»:2:17:
1| let
2| somepkg.src = throw "invalid foobar";
| ^
3| in somepkg.src.meta
error: invalid foobar
And for type errors, from:
let
somepkg.src = "I'm not an attrset";
in somepkg.src.meta
error:
… while evaluating the attribute 'src.meta'
at «string»:2:3:
1| let
2| somepkg.src = "I'm not an attrset";
| ^
3| in somepkg.src.meta
… while selecting an attribute
at «string»:3:4:
2| somepkg.src = "I'm not an attrset";
3| in somepkg.src.meta
| ^
error: expected a set but found a string: "I'm not an attrset"
into:
let
somepkg.src = "I'm not an attrset";
in somepkg.src.meta
error:
… while evaluating the attribute 'src.meta'
at «string»:2:3:
1| let
2| somepkg.src = "I'm not an attrset";
| ^
3| in somepkg.src.meta
… while selecting 'meta' on 'somepkg.src'
at «string»:3:4:
2| somepkg.src = "I'm not an attrset";
3| in somepkg.src.meta
| ^
error: expected a set but found a string: "I'm not an attrset"
For the low price of an enumerate() and a lambda you too can have the
incorrect line of code actually show up in the trace!
Change-Id: Ic1491c86e33c167891bdac9adad6224784760bd6
Turns errors like:
let
errpkg = throw "invalid foobar";
in errpkg.meta
error:
… while calling the 'throw' builtin
at «string»:2:12:
1| let
2| errpkg = throw "invalid foobar";
| ^
3| in errpkg.meta
error: invalid foobar
into errors like:
let
errpkg = throw "invalid foobar";
in errpkg.meta
error:
… while evaluating 'errpkg' to select 'meta' on it
at «string»:3:4:
2| errpkg = throw "invalid foobar";
3| in errpkg.meta
| ^
… while calling the 'throw' builtin
at «string»:2:12:
1| let
2| errpkg = throw "invalid foobar";
| ^
3| in errpkg.meta
error: invalid foobar
For the low price of one try/catch, you too can have the incorrect line
of code actually show up in the trace!
Change-Id: If8d6200ec1567706669d405c34adcd7e2d2cd29d
The `allow-flake-configuration` option allows the user to control whether to
accept configuration options supplied by flakes. Unfortunately, setting this
to false really meant "ask each time" (with an option to remember the choice
for each specific option encountered). Let no mean no, and introduce (and
default to) a separate value for the "ask each time" behaviour.
Co-Authored-By: Jade Lovelace <lix@jade.fyi>
Change-Id: I7ccd67a95bfc92cffc1ebdc972d243f5191cc1b4
We previously allowed you to map any flake URL to any other flake URL,
including shorthand flakerefs, indirect flake URLs like `flake:nixpkgs`,
direct flake URLs like `github:NixOS/nixpkgs`, or local paths.
But flake registry entries mapping from direct flake URLs often come
from swapping the 'from' and 'to' arguments by accident, and even when
created intentionally, they may not actually work correctly.
This patch rejects those URLs (and fully-qualified flake: URLs), making
it harder to swap the arguments by accident.
Fixes#181.
Change-Id: I24713643a534166c052719b8770a4edfcfdb8cf3
this gives about 20% performance improvements on pure parsing. obviously
it will be less on full eval, but depending on how much parsing is to be
done (e.g. including hackage-packages.nix or not) it's more like 4%-10%.
this has been tested (with thousands of core hours of fuzzing) to ensure
that the ASTs produced by the new parser are exactly the same as the old
one would have produced. error messages will change (sometimes by a lot)
and are not yet perfect, but we would rather leave this as is for later.
test results for running only the parser (excluding the variable binding
code) in a tight loop with inputs and parameters as given are promising:
- 40% faster on lix's package.nix at 10000 iterations
- 1.3% faster on nixpkgs all-packages.nix at 1000 iterations
- equivalent on all of nixpkgs concatenated at 100 iterations
(excluding invalid files, each file surrounded with parens)
more realistic benchmarks are somewhere in between the extremes, parsing
once again getting the largest uplift. other realistic workloads improve
by a few percentage points as well, notably system builds are 4% faster.
Benchmarks summary (from ./bench/summarize.jq bench/bench-*.json)
old/bin/nix --extra-experimental-features 'nix-command flakes' eval -f bench/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
mean: 0.408s ± 0.025s
user: 0.355s | system: 0.033s
median: 0.389s
range: 0.388s ... 0.442s
relative: 1
new/bin/nix --extra-experimental-features 'nix-command flakes' eval -f bench/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
mean: 0.332s ± 0.024s
user: 0.279s | system: 0.033s
median: 0.314s
range: 0.313s ... 0.361s
relative: 0.814
---
old/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 6.133s ± 0.022s
user: 5.395s | system: 0.437s
median: 6.128s
range: 6.099s ... 6.183s
relative: 1
new/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 5.925s ± 0.025s
user: 5.176s | system: 0.456s
median: 5.934s
range: 5.861s ... 5.943s
relative: 0.966
---
GC_INITIAL_HEAP_SIZE=10g old/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 4.503s ± 0.027s
user: 3.731s | system: 0.547s
median: 4.499s
range: 4.478s ... 4.541s
relative: 1
GC_INITIAL_HEAP_SIZE=10g new/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 4.285s ± 0.031s
user: 3.504s | system: 0.571s
median: 4.281s
range: 4.221s ... 4.328s
relative: 0.951
---
old/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello
mean: 16.475s ± 0.07s
user: 14.088s | system: 1.572s
median: 16.495s
range: 16.351s ... 16.536s
relative: 1
new/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello
mean: 15.973s ± 0.013s
user: 13.558s | system: 1.615s
median: 15.973s
range: 15.946s ... 15.99s
relative: 0.97
---
Change-Id: Ie66ec2d045dec964632c6541e25f8f0797319ee2
This reverts commit 35eec921af.
Reason for revert: Regressed nix-eval-jobs, and it appears to be this change is buggy/missing a case. It just needs another pass.
Code causing the problem in n-e-j, when invoked with `nix-eval-jobs --flake '.#hydraJobs'`:
```
n-e-j/tests/assets » ../../build/src/nix-eval-jobs --meta --workers 1 --flake .#hydraJobs
warning: unknown setting 'trusted-users'
warning: `--gc-roots-dir' not specified
error: unsupported Git input attribute 'dir'
error: worker error: error: unsupported Git input attribute 'dir'
```
```
nix::Value *vRoot = [&]() {
if (args.flake) {
auto [flakeRef, fragment, outputSpec] =
nix::parseFlakeRefWithFragmentAndExtendedOutputsSpec(
args.releaseExpr, nix::absPath("."));
nix::InstallableFlake flake{
{}, state, std::move(flakeRef), fragment, outputSpec,
{}, {}, args.lockFlags};
return flake.toValue(*state).first;
} else {
return releaseExprTopLevelValue(*state, autoArgs, args);
}
}();
```
Inspecting the program behaviour reveals that `dir` was in fact set in the URL going into the fetcher. This is in turn because unlike in the case changed in this commit, it was not erased before handing it to libfetchers, which is probably just a mistake.
```
(rr) up
3 0x00007ffff60262ae in nix::fetchers::Input::fromURL (url=..., requireTree=requireTree@entry=true) at src/libfetchers/fetchers.cc:39
warning: Source file is more recent than executable.
39 auto res = inputScheme->inputFromURL(url, requireTree);
(rr) p url
$1 = (const nix::ParsedURL &) @0x7fffdc874190: {url = "git+file:///home/jade/lix/nix-eval-jobs",
base = "git+file:///home/jade/lix/nix-eval-jobs", scheme = "git+file", authority = std::optional<std::string> = {[contained value] = ""},
path = "/home/jade/lix/nix-eval-jobs", query = std::map with 1 element = {["dir"] = "tests/assets"}, fragment = ""}
(rr) up
4 0x00007ffff789d904 in nix::parseFlakeRefWithFragment (url=".#hydraJobs", baseDir=std::optional<std::string> = {...},
allowMissing=allowMissing@entry=false, isFlake=isFlake@entry=true) at src/libexpr/flake/flakeref.cc:179
warning: Source file is more recent than executable.
179 FlakeRef(Input::fromURL(parsedURL, isFlake), getOr(parsedURL.query, "dir", "")),
(rr) p parsedURL
$2 = {url = "git+file:///home/jade/lix/nix-eval-jobs", base = "git+file:///home/jade/lix/nix-eval-jobs", scheme = "git+file",
authority = std::optional<std::string> = {[contained value] = ""}, path = "/home/jade/lix/nix-eval-jobs", query = std::map with 1 element = {
["dir"] = "tests/assets"}, fragment = ""}
(rr) list
174
175 if (pathExists(flakeRoot + "/.git/shallow"))
176 parsedURL.query.insert_or_assign("shallow", "1");
177
178 return std::make_pair(
179 FlakeRef(Input::fromURL(parsedURL, isFlake), getOr(parsedURL.query, "dir", "")),
180 fragment);
181 }
```
Change-Id: Ib55a882eaeb3e59228857761dc1e3b2e366b0f5e
The original idea was to fix lix#174, but for a user friendly solution,
I figured that we'd need more consistency:
* Invalid query params will cause an error, just like invalid
attributes. This has the following two consequences:
* The `?dir=`-param from flakes will be removed before the URL to be
fetched is passed to libfetchers.
* The tarball fetcher doesn't allow URLs with custom query params
anymore. I think this was questionable anyways given that an
arbitrary set of query params was silently removed from the URL you
wanted to fetch. The correct way is to use an attribute-set
with a key `url` that contains the tarball URL to fetch.
* Same for the git & mercurial fetchers: in that case it doesn't even
matter though: both fetchers added unused query params to the URL
that's passed from the input scheme to the fetcher (`url2` in the code).
It turns out that this was never used since the query parameters were
erased again in `getActualUrl`.
* Validation happens for both attributes and URLs. Previously, a lot of
fetchers validated e.g. refs/revs only when specified in a URL and
the validity of attribute names only in `inputFromAttrs`.
Now, all the validation is done in `inputFromAttrs` and `inputFromURL`
constructs attributes that will be passed to `inputFromAttrs`.
* Accept all attributes as URL query parameters. That also includes
lesser used ones such as `narHash`.
And "output" attributes like `lastModified`: these could be declared
already when declaring inputs as attribute rather than URL. Now the
behavior is at least consistent.
Personally, I think we should differentiate in the future between
"fetched input" (basically the attr-set that ends up in the lock-file)
and "unfetched input" earlier: both inputFrom{Attrs,URL} entrypoints
are probably OK for unfetched inputs, but for locked/fetched inputs
a custom entrypoint should be used. Then, the current entrypoints
wouldn't have to allow these attributes anymore.
Change-Id: I1be1992249f7af8287cfc37891ab505ddaa2e8cd
We got UBSan working on Lix, so we of course immediately found a bug and
some definitely nonsense behaviour.
Accessing `pureEval` or `restrictEval` from a default setting value is
nonsense, since they would never be actually set by the time that value
is set so they are not going to do anything. The configuration is not
applied in an initializer (and even if it were, it's not going to be in
the right order).
After looking into *that*, we hunted down what actually was applying
these, since clearly this code did not do anything. The EvalState
constructor should have a "search path added and removed here :)" sign
on it, because that's where it is done. We added an explicit
initialization of the optional in there because it was otherwise unclear
why pureEval also has the search path to allowed paths setup code run.
We then realized that the `pureEval` documentation was *also* bogus, and
we rewrote it. In so doing, we realized that we forgot to file a bug to
make `builtins.storePath` work in pure eval mode, so we filed one of
those: lix-project/lix#402
Yaks have been thoroughly shorn.
UBSan report:
../src/libexpr/eval-settings.cc:66:10: runtime error: member call on address 0x752fa9a13060 which does not point to an object of type 'nix::BaseSetting<b
ool>'
0x752fa9a13060: note: object has invalid vptr
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^~~~~~~~~~~~~~~~~~~~~~~
invalid vptr
0 0x752fa95106a6 in nix::EvalSettings::getDefaultNixPath[abi:cxx11]() /home/jade/lix/lix2/build/src/libexpr/eval-settings.cc:66:10
1 0x752fa950e420 in nix::EvalSettings::EvalSettings() /home/jade/lix/lix2/build/src/libexpr/eval-settings.hh:36:15
2 0x752fa9469f1f in __cxx_global_var_init.50 /home/jade/lix/lix2/build/src/libexpr/eval-settings.cc:98:14
3 0x752fa9469f1f in _GLOBAL__sub_I_eval_settings.cc /home/jade/lix/lix2/build/src/libexpr/eval-settings.cc
4 0x752fabbd308d in call_init (/nix/store/k7zgvzp2r31zkg9xqgjim7mbknryv6bs-glibc-2.39-52/lib/ld-linux-x86-64.so.2+0x508d) (BuildId: a5b8228edc9f16078ac3c894af964eeb990ecb4c)
5 0x752fabbd317b in _dl_init (/nix/store/k7zgvzp2r31zkg9xqgjim7mbknryv6bs-glibc-2.39-52/lib/ld-linux-x86-64.so.2+0x517b) (BuildId: a5b8228edc9f16078ac3c894af964eeb990ecb4c)
6 0x752fabbe9c2f in _dl_start_user (/nix/store/k7zgvzp2r31zkg9xqgjim7mbknryv6bs-glibc-2.39-52/lib/ld-linux-x86-64.so.2+0x1bc2f) (BuildId: a5b8228edc9f16078ac3c894af964eeb990ecb4c)
Change-Id: I5d8ffb7bfbe24b6584020ac74eed93d9f2e6d111
with the prepatory work done this mostly means turning plain pointers
into unique_ptrs, with all the associated churn that necessitates. we
might want to change some of these to box_ptrs at some point as well,
but that would be a semantic change that isn't fully appropriate yet.
Change-Id: I0c238c118617420650432f4ed45569baa3e3f413
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
now that destructors are hooked up we want to give the C skeleton every
real chance to actually run them. since bison does not call destructors
on values that have been passed to semantic actions even when an action
causes an abort we will also have to delete some things manually still.
Change-Id: Ia22bdaa9e969b74e17a6c496e35e6c2d86b7d750
this doesn't help much yet since the state objects themselves also leak
all memory they are given, but it is a first necessary step to properly
managing parser memory. notably we have to clear $$ when returning from
the parser since even the start symbol is subject to automatic deletion
by the bison-generated parser before returning control to the call site
Change-Id: I80245b0c747308e80923e7f18ce4e1a4898f93b0
* changes:
Change error messages about 'invalid paths' to 'path does not exist'.
Add a clearer error message for InvalidPathError during evaluation
Harmonise the Store::queryPathInfoUncached interface
They are enabled by default, and Meson will also prints whether or not
they're enabled at the bottom at the end of configuration.
Change-Id: I48db238510bf9e74340b86f243f4bbe360794281
eldritch horrors
Qyriad
jade
alois31
nan-git
Delan Azabani
Maximilian Bosch
julia