Rather than "mounting" the store inside an empty virtual filesystem,
just return the store as a virtual filesystem. This is more modular.
(FWIW, it also supports two long term hopes of mind:
1. More capability-based Nix language mode. I dream of a "super pure
eval" where you can only use relative path literals (See #8738), and
any `fetchTree`-fetched stuff + the store are all disjoint (none is
mounted in another) file systems.
2. Windows, where the store dir may include drive letters, etc., and is
thus unsuitable to be the prefix of any `CanonPath`s.
)
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
We now mount lazy accessors on top of /nix/store without materializing
them, and only materialize them to the real store if needed (e.g. in
the `derivation` primop).
For example, instead of doing
#include "nix/store-config.hh"
#include "nix/derived-path.hh"
Now do
#include "nix/store/config.hh"
#include "nix/store/derived-path.hh"
This was originally planned in the issue, and also recent requested by
Eelco.
Most of the change is purely mechanical. There is just one small
additional issue. See how, in the example above, we took this
opportunity to also turn `<comp>-config.hh` into `<comp>/config.hh`.
Well, there was already a `nix/util/config.{cc,hh}`. Even though there
is not a public configuration header for libutil (which also would be
called `nix/util/config.{cc,hh}`) that's still confusing, To avoid any
such confusion, we renamed that to `nix/util/configuration.{cc,hh}`.
Finally, note that the libflake headers already did this, so we didn't
need to do anything to them. We wouldn't want to mistakenly get
`nix/flake/flake/flake.hh`!
Progress on #7876
(cherry picked from commit cc24766fa6)
This way, we don't need the PathDisplaySourceAccessor source accessor
hack, since error messages are produced directly by the original
source accessor.
In fact, we don't even need to copy the inputs to the store at all, so
this gets us very close to lazy trees. We just need to know the store
path so that requires hashing the entire input, which isn't lazy. But
the next step will be to use a virtual store path that gets rewritten
to the actual store path only when needed.
For example, instead of doing
#include "nix/store-config.hh"
#include "nix/derived-path.hh"
Now do
#include "nix/store/config.hh"
#include "nix/store/derived-path.hh"
This was originally planned in the issue, and also recent requested by
Eelco.
Most of the change is purely mechanical. There is just one small
additional issue. See how, in the example above, we took this
opportunity to also turn `<comp>-config.hh` into `<comp>/config.hh`.
Well, there was already a `nix/util/config.{cc,hh}`. Even though there
is not a public configuration header for libutil (which also would be
called `nix/util/config.{cc,hh}`) that's still confusing, To avoid any
such confusion, we renamed that to `nix/util/configuration.{cc,hh}`.
Finally, note that the libflake headers already did this, so we didn't
need to do anything to them. We wouldn't want to mistakenly get
`nix/flake/flake/flake.hh`!
Progress on #7876
at least clang-tidy is not convinced that this initialized.
If this is not the case, the impact should be small and hopefully also
more robust if changed.
(cherry picked from commit 7e540059a3)
There are two big changes:
1. Public and private config is now separated. Configuration variables
that are only used internally do not go in a header which is
installed.
(Additionally, libutil has a unix-specific private config header,
which should only be used in unix-specific code. This keeps things a
bit more organized, in a purely private implementation-internal way.)
2. Secondly, there is no more `-include`. There are very few config
items that need to be publically exposed, so now it is feasible to
just make the headers that need them just including the (public)
configuration header.
And there are also a few more small cleanups on top of those:
- The configuration files have better names.
- The few CPP variables that remain exposed in the public headers are
now also renamed to always start with `NIX_`. This ensures they should
not conflict with variables defined elsewhere.
- We now always use `#if` and not `#ifdef`/`#ifndef` for our
configuration variables, which helps avoid bugs by requiring that
variables must be defined in all cases.
(cherry picked from commit c204e307ac)
This makes paths in error messages behave similar to lazy-trees,
e.g. instead of store paths like
error: attribute 'foobar' missing
at /nix/store/ddzfiipzqlrh3gnprmqbadnsnrxsmc9i-source/machine/configuration.nix:209:7:
208|
209| pkgs.foobar
| ^
210| ];
you now get
error: attribute 'foobar' missing
at /home/eelco/Misc/eelco-configurations/machine/configuration.nix:209:7:
208|
209| pkgs.foobar
| ^
210| ];
There are two big changes:
1. Public and private config is now separated. Configuration variables
that are only used internally do not go in a header which is
installed.
(Additionally, libutil has a unix-specific private config header,
which should only be used in unix-specific code. This keeps things a
bit more organized, in a purely private implementation-internal way.)
2. Secondly, there is no more `-include`. There are very few config
items that need to be publically exposed, so now it is feasible to
just make the headers that need them just including the (public)
configuration header.
And there are also a few more small cleanups on top of those:
- The configuration files have better names.
- The few CPP variables that remain exposed in the public headers are
now also renamed to always start with `NIX_`. This ensures they should
not conflict with variables defined elsewhere.
- We now always use `#if` and not `#ifdef`/`#ifndef` for our
configuration variables, which helps avoid bugs by requiring that
variables must be defined in all cases.
The short answer for why we need to do this is so we can consistently do
`#include "nix/..."`. Without this change, there are ways to still make
that work, but they are hacky, and they have downsides such as making it
harder to make sure headers from the wrong Nix library (e..g.
`libnixexpr` headers in `libnixutil`) aren't being used.
The C API alraedy used `nix_api_*`, so its headers are *not* put in
subdirectories accordingly.
Progress on #7876
We resisted doing this for a while because it would be annoying to not
have the header source file pairs close by / easy to change file
path/name from one to the other. But I am ameliorating that with
symlinks in the next commit.
(cherry picked from commit f3e1c47f47)
Doing this makes catching non-obvious bugs easier. GHA CI workload is
already a concern and there isn't much benefit in running the tests with
and without sanitizers at the same time, so UBSAN is enabled for default
checks.
This change doesn't affect production builds in any way, but is rather a
step in the direction of improving automated testing during development.
Relates to #10969.
(cherry picked from commit 874587516c)
- Some headers were completely redundant and have been removed.
- Other headers have been turned private.
- Unnecessary meson.build code has been removed.
- libutil-tests now has a private config header, where previously
it had none. This removes the need to expose a package version
macro publicly.
(cherry picked from commit b86a76044e)
The short answer for why we need to do this is so we can consistently do
`#include "nix/..."`. Without this change, there are ways to still make
that work, but they are hacky, and they have downsides such as making it
harder to make sure headers from the wrong Nix library (e..g.
`libnixexpr` headers in `libnixutil`) aren't being used.
The C API alraedy used `nix_api_*`, so its headers are *not* put in
subdirectories accordingly.
Progress on #7876
We resisted doing this for a while because it would be annoying to not
have the header source file pairs close by / easy to change file
path/name from one to the other. But I am ameliorating that with
symlinks in the next commit.
I encountered this with a misconfigured libutil. I doubt that a
non-lutimes config is viable, because tests were failing.
(cherry picked from commit 1cffcd91a9)
- Some headers were completely redundant and have been removed.
- Other headers have been turned private.
- Unnecessary meson.build code has been removed.
- libutil-tests now has a private config header, where previously
it had none. This removes the need to expose a package version
macro publicly.
at least clang-tidy is not convinced that this initialized.
If this is not the case, the impact should be small and hopefully also
more robust if changed.
