thunk values are shareable, and we can represent invalid/uninitialized
values with a special bit pattern that makes no sense otherwise. there
is no need to keep allocating values on the heap, instead we can treat
values like reference-counted smart pointers to heap objects, which in
turn lets us save a lot of allocations and, ultimately, gc heap space.
compared to our baseline (main of 2025-09-27) we save 15%+ memory on a
system rebuild and 17% on nix search. eval time regresses by ~3% for a
system rebuild, while nix search is 7% faster. further optimization is
probably possible (but for now this will just have to be good enough).
Change-Id: Ib6c47acdbe2fac4f76a83c2269f16f30ef66b2e1
In preparations for a new representation of bindings that will make it
impossible to write an efficient `Bindings::find`.
Change-Id: I4e5a25b8d37d01b5728f7fe43978ceda2ab1b9b6
Signed-off-by: Raito Bezarius <raito@lix.systems>
Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>
It's pretty bad that Bindings effectively wasted whole 8
bytes (4 for capacity and + 4 for alignment padding) to
store something it doesn't actually need. BindingsBuilder
allows the capacity to be checked at construction time,
after which the Bindings does not get mutated aside from
the ugly case of builtins, which doesn't get built all
at once.
For `nix search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello`
this shaves off around 53MB allocations out of 2GB used
for attrsets in total:
< "bytes": 2001170768,
---
> "bytes": 1947398072,
< "Bindings": 16,
---
> "Bindings": 8,
Nix PR: https://github.com/NixOS/nix/pull/13919
Change-Id: I939c5ac545f5abbca048370dcf4936346339d75c
Concept: what if you could, in your fancy terminal, in the year of our
lord 2025, just click on the attrs you're looking at to go to where
they're defined. Currently we only expose this info as
builtins.unsafeGetAttrPos, which is inconvenient as it's not
discoverable to users.
By putting it in this more visible yet invisible spot, it's more likely
to be more useful to more people.
In the current state, this is not the most useful ever due to stuff like
https://github.com/neovim/neovim/discussions/35097. However, it can be
expanded by perhaps adding something like the url format setting ripgrep
has.
Change-Id: I3947f97d5c2056d59099af468d7b855486438227
This cleans up includes that clangd reports as unused, usually by deleting the offending include. The process was to delete an include and see if it still builds. If not, try to find a more specific include(s) that works, that was previously transitively included. If the original include seems intended to re-export said transitive include, mark the transitive include as `// IWYU pragma: export`. Otherwise, replace the original include with the transitive include(s). If none of the above applies, because the original file depends on code directly in the include somehow, or the direct include is an external dependency that cannot be modified, restore the original include and mark it as `// IWYU pragma: keep`.
Change-Id: I5ce3d34dad76b0cad0a6a7990fea13add393aad3
Calling a custom type size_t is incredibly sneaky and makes all the code
around this extremely context dependent.
Change-Id: Idae684781f45fe615020d8642f12a656ab2c15ad
these do not rely on the GC being initialized. there's no reason for
them to not be statics, shared between all eval states in a process.
Change-Id: Ib9675f3945d3a0a7097d6c85096adcbd6f441d83
clangd broke because it can't look through symlinks. compile_commands
manipulation does not fix it, clangd configuration does not fix it, a
vfs overlay does not fix it, and while a combination of those can fix
it with a bind mount in place that's just too cursed to even consider
clangd bug: https://github.com/llvm/llvm-project/issues/116877
Change-Id: I8e3e8489548eb3a7aa65ac9d12a5ec8abf814aec
eldritch horrors