Since the parser is now LALR we can easily switch
over to the less ugly sketelon than the default C one.
This would allow us to switch from %union to %define api.value.type variant
in the future to avoid the need for triviall POD types.
1. Saves 24-32 bytes per string (size of std::string)
2. Saves additional bytes by not over-allocating strings (in total we
save ~1% memory)
3. Sets us up to perform a similar transformation on the other Expr
subclasses
4. Makes ExprString trivially moveable (before the string data might
move, causing the Value's pointer to become invalid). This is important
so we can put ExprStrings in an std::vector and refer to them by index
We have introduced a string copy in ParserState::stripIndentation().
This could be removed by pre-allocating the right sized string in the
arena, but this adds complexity and doesn't seem to improve performance,
so for now we've left the copy in.
This mirrors what OptionalPathSetting does. Otherwise we run into
an assertion failure for relative paths specified as the authority + path:
nix build nixpkgs#hello --store "local://a/b"
nix: ../posix-source-accessor.cc:13: nix::PosixSourceAccessor::PosixSourceAccessor(std::filesystem::__cxx11::path&&): Assertion `root.empty() || root.is_absolute()' failed.
This is now diagnosed properly:
error: not an absolute path: 'a/b'
Just as you'd specify the root via a query parameter:
nix build nixpkgs#hello --store "local?root=a/b"
Fewer macros is better!
Introduce a new `JsonChacterizationTest` mixin class to help with this.
Also, avoid some needless copies with `GetParam`.
Part of my effort shoring up the JSON formats with #13570.
These stragglers have been accidentally left out when implementing the StoreConfig::getReference.
Also HttpBinaryCacheStore::getReference now returns the actual store parameters, not the cacheUri
parameters.
In the case where the store object doesn't exist, we do correctly move
(rather than copy) the scratch data into place. In this case, the
destination store object already exists, but we still want to clean up
after ourselves.
This avoids any complications that can arise from the environment
affecting evaluation of the help pages (which don't need to be calling
out to anything external anyways)
A recent example of one of these problems is
https://github.com/NixOS/nix/issues/14085, which would break help pages
by causing them to make invalid calls to the dummy store they're
evaluated with
Fixes: https://github.com/NixOS/nix/issues/14062
Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>