almost all uses of this are interactive, except for deepSeq. deepSeq is
going to be expensive and rare enough to not care much about, and
Value::determinePos should usually be cheap enough to not be too much of
a burden in any case.
~1% parser speedup from not using TLS indirections, less on system eval.
this could have also gone in flex yyextra data, but that's significantly
slower for some reason (albeit still faster than thread locals).
before:
Time (mean ± σ): 4.231 s ± 0.004 s [User: 3.725 s, System: 0.504 s]
Range (min … max): 4.226 s … 4.240 s 10 runs
after:
Time (mean ± σ): 4.224 s ± 0.005 s [User: 3.711 s, System: 0.512 s]
Range (min … max): 4.218 s … 4.234 s 10 runs
~2% speedup on parsing without eval, less (but still significant) on
system eval. having flex generate faster parsers leads to very strange
misparses. maybe re2c is worth investigating.
before:
Time (mean ± σ): 4.260 s ± 0.003 s [User: 3.754 s, System: 0.505 s]
Range (min … max): 4.257 s … 4.266 s 10 runs
after:
Time (mean ± σ): 4.231 s ± 0.004 s [User: 3.725 s, System: 0.504 s]
Range (min … max): 4.226 s … 4.240 s 10 runs
checking for isBlackhole in the forceValue hot path is rather more
expensive than necessary, and with a little bit of trickery we can move
such handling into the isApp case. small performance benefit, but under
some circumstances we've seen 2% improvement as well.
〉 nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
before:
Time (mean ± σ): 4.429 s ± 0.002 s [User: 3.929 s, System: 0.500 s]
Range (min … max): 4.427 s … 4.433 s 10 runs
after:
Time (mean ± σ): 4.396 s ± 0.002 s [User: 3.894 s, System: 0.501 s]
Range (min … max): 4.393 s … 4.399 s 10 runs
`eval-system` option overrides just the value of `builtins.currentSystem`.
This is more useful than overriding `system` since you can build these
derivations on remote builders which can work on the given system.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
* document `fetchTree`
* display experimental feature note at the top
we have to enable the new `fetchTree` experimental feature to render it
at all. this was a bug introduced when adding that new feature flag.
Co-authored-by: tomberek <tomberek@users.noreply.github.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Silvan Mosberger <github@infinisil.com>
According https://en.cppreference.com/w/cpp/io/strstream, it has been
deprecated since C++98! The Clang + Linux build systems to not have it
at all, or at least be hiding it.
We can just use `std::stringstream` instead, I think.
* Print the value in `error: cannot coerce` messages
This extends the `error: cannot coerce a TYPE to a string` message
to print the value that could not be coerced. This helps with debugging
by making it easier to track down where the value is being produced
from, especially in errors with deep or unhelpful stack traces.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This includes position information in more places, making debugging
easier.
Before:
```
$ nix-instantiate --show-trace --eval tests/functional/lang/eval-fail-using-set-as-attr-name.nix
error:
… while evaluating an attribute name
at «none»:0: (source not available)
error: value is a set while a string was expected
```
After:
```
error:
… while evaluating an attribute name
at /pwd/lang/eval-fail-using-set-as-attr-name.nix:5:10:
4| in
5| attr.${key}
| ^
6|
error: value is a set while a string was expected
```
Today, with the tests inside a `tests` intermingled with the
corresponding library's source code, we have a few problems:
- We have to be careful that wildcards don't end up with tests being
built as part of Nix proper, or test headers being installed as part
of Nix proper.
- Tests in libraries but not executables is not right:
- It means each executable runs the previous unit tests again, because
it needs the libraries.
- It doesn't work right on Windows, which doesn't want you to load a
DLL just for the side global variable . It could be made to work
with the dlopen equivalent, but that's gross!
This reorg solves these problems.
There is a remaining problem which is that sibbling headers (like
`hash.hh` the test header vs `hash.hh` the main `libnixutil` header) end
up shadowing each other. This PR doesn't solve that. That is left as
future work for a future PR.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This makes for more useful manual table of contents, that displays the
information at a glance.
The `nix help-stores` command is kept as-is, even though it will show up
in the manual with the same information as these pages due to the way it
is written as a "`--help`-style" command. Deciding what to do with that
command is left for a later PR.
This change also lists all store types at the top of the respective overview page.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems
`installcheck` doesn't yet work, but the rest of the build can now
happen mostly inside a separate build directory.
Progress on #9342
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Without the change build for `eval.o` fails occasionally as:
$ make src/libexpr/eval.o
GEN Makefile.config
GEN src/libexpr/primops/derivation.nix.gen.hh
GEN src/libexpr/fetchurl.nix.gen.hh
GEN src/libexpr/parser-tab.cc
GEN src/libexpr/lexer-tab.cc
src/libexpr/lexer.l:314: warning, -s option given but default rule can be matched
CXX src/libexpr/eval.o
src/libexpr/eval.cc:519:18: fatal error: flake/call-flake.nix.gen.hh: No such file or directory
519 | #include "flake/call-flake.nix.gen.hh"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [mk/patterns.mk:3: src/libexpr/eval.o] Error 1
Noticed in https://github.com/NixOS/nixpkgs/pull/269439
* doc: primops: add more info for foldl
From the existing doc it is not obvious whether the first or the
second argument is the accumulator. This is however relevant to
know, as for certain scenarios, this might change the behavior.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
