nlohmann has customization points for exception throws. we can use these
instead and wrap json exceptions at the source instead of playing a game
of whack-a-mole with json errors all over the tree. since nlohmann needs
macros set to achieve this we can no longer precompile its headers *and*
must forbid including it anywhere without the proper defines or ordering
of include directives will break lix with ODR violations, if we see them
at all before we get another json-related bug report. a new lint will be
in charge of ensuring this doesn't happen. we also re-allow direct calls
to nlohmann json parsing since error handling is no longer a problem. we
will keep the wrapper for more convenient error context handling though.
fixes#1092
Change-Id: I54ecc14f5bec5e2177729b41c3703216e76cc6a3
this is a strong prerequisite for making values themselves copyable
without duplicating evaluation side effects. with this we can treat
`Value` the way we treated `Value *` to date and drop indirections.
Change-Id: I08f30d12697614a3ae7149615f6f1da83b13f52b
on its own this is not very useful, but having accessors for every value
kind is a prerequisite for doing smart things with Value than the union.
the net effect for now is only to add a few parentheses across the tree.
Change-Id: I88688ac09eb08495dad1eb221034ca540f094950
notably this also includes the symbol table because it stores real
strings that are referenced by eval values, and an upcoming change
will make it impossible to share those strings with value strings.
Change-Id: I20a3644db8aa0850efe29630e0b73d424cb2aa56
The backing storage for symbols becomes a class storing a Value and a
string.
The Value is itself a string which contents points to the owned string.
Recovering a `SymbolStr` is still possible.
Change-Id: I171151abc3c0a513f2150c4b54edd61dea256cce
Signed-off-by: Raito Bezarius <raito@lix.systems>
`ExprConcatStrings` tracks whether the expression is an interpolation or
not via an obscure boolean called `forceString`.
Instead, we rename it to `isInterpolation`.
This is a breaking change for the JSON AST representation.
Change-Id: I9f89337449b56f6e99a961e21169761f554c9896
Signed-off-by: Raito Bezarius <raito@lix.systems>
this way we don't have to even check whether we need a debug frame when
the debugger isn't enabled. not doing this gives us an eval performance
improvement of roughly 7% on nixos system eval and 2% for `nix search`.
Change-Id: I1cdad3de61f865ea54d6e09d63a281688e828768
we'll want to wrap some exprs for debug purposes, and dynamic casts
cannot look through such wrappers. dedicated casting functions can.
Change-Id: I1fba0ec52d281a1b8de85a62e4948bfae536bcfc
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
this only affects undefined names outside of with scopes. sending those
errors to the debugger when enabled seems rather less useful; unlike in
the case of with scopes there's nothing meaningful to inspect. avoiding
the debugger also lets us avoid marking the entire parser `NeverAsync`.
cf #761
Change-Id: I3599b826ff5b101acf9a3ba70dcdf9e8e02067f0
this will become a proper specialization of `nlohmann::basic_json` soon.
specialing basic_json will let us get rid of our `adl_serializer` hacks,
and it'll open the door to better enum serializing behavior without also
forcing all those who use lix as a library to set certain defines (which
may not even be possible depending on how those users use json already).
Change-Id: I5228d2b9df581a189552c993363207cfbd20f445
This is kind of a painful change, because a lot of code grew around the
bad abstraction, but the goal here is to abstract formals in a way that
allows adding other means of pattern matching / argument destructuring
in the future.
Change-Id: If4e681a4be3d1f42ceea81a8e07297f0d08acc80
The code for serialization Expr nodes back into (pseudo-)Nix has been
removed for being subtly error-prone and tedious to maintain. Instead,
`nix-instantiate --parse` now prints a JSON representation of the AST.
Usage patterns of the --parse flag I've found in the wild:
1. Check if a file is well-formed, i.e. discard output and test exit code
2. Get parser errors from a file, i.e. discard stdout and use stderr
3. Nixfmt uses --parse to test equivalence pre/post format, and that property is (should be?) preserved
None of these should break with the current change
Closes#487
Change-Id: Icdbaad17790f2ad8765fa08e02e6597ee4c7a909
This is a pretty small change because the parser already has all
necessary information (needed for parse errors), now we want to keep it
to also provide better eval errors.
Change-Id: Ifc7a9516b9b0c8d9698f1899a6912ae91f6696ab
ExprLet was previously inheriting from ExprAttrs for the data, while
ignoring all
set-specific operations on it. The set specific code has now been split
off so that
let doesn't inherit it anymore:
- ExprAttrs (not an Expr), containing the attributes and the related
logic
- ExprLet : Expr, ExprAttrs
- ExprSet : Expr, ExprAttrs
Co-authored-by: eldritch horrors <pennae@lix.systems>
Change-Id: I63f2fbcd1e790b3cffb56eec1e7565ee3cdbf964
this finally gives us a witness type we can use to prove that a certain
call graph subtree can't be used in kj promises using only a single new
assumption: if EvalState& is never held as a reference member of a type
and instead only ever passes as an argument or held on the stack we can
be certain that anything that has access to en EvalState ref must never
be run inside a promise and, crucially, that anything that doesn't have
access to an EvalState& *can* be run inside a promise without problems.
Change-Id: I6c15ada479175ad7e6cd3e4a729a5586b3ba30d6
this will let us pass the capability to create debuggable eval errors
without having to pass an entire EvalState. we could pass symbols and
debug states around just as easily, but if we add new capabilities to
our debugger we might have to change many more places than with this.
Change-Id: I2f8893012e5d98a986ef1fc888234c2dd8d5e096
It was never intended to be a feature to be used, and moreover it is
inconsistent: One cannot override `+`, and overriding `__lessThan` won't
affect the builtins which do comparisons.
Change-Id: Iaba54a05aa4c2eb37cdb3dc0d731fcee5a86deba
just to keep debug-related state closer together. eventually this will
also allow us to not allocate debugger state altogether unless needed.
Change-Id: Id83fea75d96d0ecbe21683cb1b57dd5b11b13535
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