Today, with the tests inside a `tests` intermingled with the
corresponding library's source code, we have a few problems:
- We have to be careful that wildcards don't end up with tests being
built as part of Nix proper, or test headers being installed as part
of Nix proper.
- Tests in libraries but not executables is not right:
- It means each executable runs the previous unit tests again, because
it needs the libraries.
- It doesn't work right on Windows, which doesn't want you to load a
DLL just for the side global variable . It could be made to work
with the dlopen equivalent, but that's gross!
This reorg solves these problems.
There is a remaining problem which is that sibbling headers (like
`hash.hh` the test header vs `hash.hh` the main `libnixutil` header) end
up shadowing each other. This PR doesn't solve that. That is left as
future work for a future PR.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This makes for more useful manual table of contents, that displays the
information at a glance.
The `nix help-stores` command is kept as-is, even though it will show up
in the manual with the same information as these pages due to the way it
is written as a "`--help`-style" command. Deciding what to do with that
command is left for a later PR.
This change also lists all store types at the top of the respective overview page.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems
`installcheck` doesn't yet work, but the rest of the build can now
happen mostly inside a separate build directory.
Progress on #9342
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Without the change build for `eval.o` fails occasionally as:
$ make src/libexpr/eval.o
GEN Makefile.config
GEN src/libexpr/primops/derivation.nix.gen.hh
GEN src/libexpr/fetchurl.nix.gen.hh
GEN src/libexpr/parser-tab.cc
GEN src/libexpr/lexer-tab.cc
src/libexpr/lexer.l:314: warning, -s option given but default rule can be matched
CXX src/libexpr/eval.o
src/libexpr/eval.cc:519:18: fatal error: flake/call-flake.nix.gen.hh: No such file or directory
519 | #include "flake/call-flake.nix.gen.hh"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [mk/patterns.mk:3: src/libexpr/eval.o] Error 1
Noticed in https://github.com/NixOS/nixpkgs/pull/269439
* doc: primops: add more info for foldl
From the existing doc it is not obvious whether the first or the
second argument is the accumulator. This is however relevant to
know, as for certain scenarios, this might change the behavior.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
https://github.com/NixOS/nixpkgs/pull/269064 makes rapidcheck be build
as a shared lib, but that broke Nix because the `-lrapidcheck` was
missing. This fixes that (and doesn't break Nix what the library is a
static archive as today).
getFlake currently calls lstat (via isLink via canonPath) before it
performs the sanity check that a flake.nix exists in the first place.
This commit moves the check to before path canonicalization, so that
failed symlink check operations don't throw before the check does.
**`Value` and `const`**
These two deserve some explanation. We'll get to lists later.
Values can normally be thought of as immutable, except they are
are also the vehicle for call by need, which must be implemented
using mutation.
This circumstance makes a `const Value` a rather useless thing:
- If it's a thunk, you can't evaluate it, except by copying, but
that would not be call by need.
- If it's not a thunk, you know the type, so the method that
acquired it for you should have returned something more specific,
such as a `const Bindings &` (which actually does make sense
because that's an immutable span of pointers to mutable `Value`s.
- If you don't care about the type yet, you might establish the
convention that `const Value` means `deepSeq`-ed data, but
this is hardly useful and not actually as safe as you would
supposedly want to trust it to be - just convention.
**Lists**
`std::span` is a tuple of pointer and size - just what we need.
We don't return them as `const Value`, because considering the
first bullet point we discussed before, we'd have to force all
the list values, which isn't what we want.
So what we end up with is a nice representation of a list in
weak head normal form: the spine is immutable, but the
items may need some evaluation later.
Closes#9343
See that issue for motivation.
Installing these is disabled by default, but we enable it (and the
additional output we want isntall these too so as not to clutter the
existing ones) to use in cross builds and dev shells.
Try to stay away from stack overflows.
These small vectors use stack space. Most instances will not need
to allocate because in general most things are small, and large
things are worth heap allocating.
16 * 3 * word = 384 bytes is still quite a bit, but these functions
tend not to be part of deep recursions.
This makes stack usage significantly more compact, allowing larger
amounts of data to be processed on the same stack.
PrimOp functions with more than 8 positional (curried) arguments
should use an attrset instead.
VLAs are a dangerous feature, and their usage triggers an undefined
behavior since theire size can be zero in some cases.
So replace them with `boost::small_vector`s which fit the same goal but
are safer.
It's also incidentally consistently 1% faster on the benchmarks.
As discussed in our last meeting, we need a bit more time, but we are
"time boxing" the work left to do to ensure there is not unbounded
delay.
Rather than putting it back underneath `flakes`, though, put it
underneath its own `fetch-tree` experimental feature (which `flakes`
includes/implies). This signals our commitment to the plan to stabilize
it first without waiting to go through the rest of Flakes, and also will
give users a "release candidate" when we get closer to stabilization.
This reverts commit 4112dd1fc9.
