The existing header is a bit too big. Now the following use-cases are
separated, and get their own headers:
- Using or implementing an arbitrary store: remaining `store-api.hh`
This is closer to just being about the `Store` (and `StoreConfig`)
classes, as one would expect.
- Opening a store from a textual description: `store-open.hh`
Opening an aribtrary store implementation like this requires some sort
of store registration mechanism to exists, but the caller doesn't need
to know how it works. This just exposes the functions which use such a
mechanism, without exposing the mechanism itself
- Registering a store implementation: `store-registration.hh`
This requires understanding how the mechanism actually works, and the
mechanism in question involves templated machinery in headers we
rather not expose to things that don't need it, as it would slow down
compilation for no reason.
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
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.
When #9863 converted the `Nix::Store` free functions into member functions, the
implicit `this` argument was not accounted for when iterating over the variable
number of arguments in some functions.
1. Fix this eval error:
https://hydra.nixos.org/jobset/nix/master#tabs-errors
The dev package output (actually a separate derivation) needs to skip
this for cross just as the main package output does.
2. Deduplicate libs attrset and list.
3. Move `nix-functional-tests` to `checkInputs`.
With the Meson build system, we no longer need a `check` vs
`install-check` distinction, so it is simpler to just keeep
everything in one place.
Upstream `bzip2` does not provide `pkg-config` files. As a result an
attempt to build `nix` on some distributions like Gentoo failos the
configure as:
$ meson setup ..
...
Executing subproject perl
...
perl| Run-time dependency bzip2 found: NO (tried pkgconfig and cmake)
../src/perl/meson.build:68:12: ERROR: Dependency "bzip2" not found, tried pkgconfig and cmake
The change falls back to `bz2` library for such cases.
... and remove a few unused arguments.
This adds pkg-config to a two or three packages that don't use it,
but we shouldn't let that bother us. It's like our personal stdenv.
This is because with the split packages of the Meson build, we simply
have no idea what directory the binaries will be installed in when we
build the library.
In the process of doing so, consolidate and make more sophisticated the
logic to cope with a few corner cases (e.g. `NIX_BIN_DIR` exists, but no
binaries are inside it).
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Inspired by
010ff57ebb
From the original PR:
> We do not have any of these warnings appearing at the moment, but
> it seems like a good idea to enable [[nodiscard]] checking anyway.
> Once we start introducing more functions with must-use conditions we will
> need such checking, and the rust stdlib has proven them very useful.
The old `std::variant` is bad because we aren't adding a new case to
`FileIngestionMethod` so much as we are defining a separate concept ---
store object content addressing rather than file system object content
addressing. As such, it is more correct to just create a fresh
enumeration.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
