This is good in general (see how the other libraries also have long had
it, since 49fe9592a4) but in particular
needed to fix the NetBSD build.
(cherry picked from commit b23273f6a2)
without knowing a lot of context, it's not clear who "we" are in that
text. I'm also strongly opposed to adding procedural notes into
a reference manual; it just won't age well.
this change leaves a factual description of the experimental feature and
its purpose.
(cherry picked from commit 3c6244b55e)
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>
(cherry picked from commit 91b6833686)
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
(cherry picked from commit 75134b7513)
up to now, those were managed outside of this repo, which as
unsurprisingly a real hassle to deal with if one wanted to prevent URLs
from breaking when moving pages around. this change removes a large part
of the friction involved in moving content in the Nix manual.
possible next steps for further automation:
- check for content that moved and warn if it's not reachable from
links that were valid prior to a change
- create redirect rules automatically based on this information
(cherry picked from commit 2b7016cc56)
This builds on #8817, to add additional UX help for people with existing
muscle memory (or shell history) with --update-input and tries to gently
guide them towards the newly evolved CLI UI.
Co-authored-by: Cole Helbling <cole.e.helbling@outlook.com>
(cherry picked from commit af00298587)
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).
(cherry picked from commit 46131567da)
Fixes:
warning: destructor called on non-final 'nix::ParseUnquoted' that has virtual functions but non-virtual destructor [-Wdelete-non-abstract-non-virtual-dtor]
**`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.
