fsync blocks until the contents have been actually written to disk,
which would be useful if we didn't want to report success until having
achieved durability. But the OS will ensure coherency; i.e. if one
process writes stuff without calling fsync, then another process reads
that stuff, the writes will be seen even if they didn't get flushed to
disk yet.
Since this code deals with ephemeral cache data, it's not worth trying
to achieve this kind of durability guarantee. This is consistent with
all the other tooling on the system.
Certainly, if we wanted to change our stance on this, it would not be
something that affects only the git fetching logic.
We're currently experimenting with backends which effectively do their
own liveness analysis, so this old trick of mine isn't necessarily valid
anymore. However, we can fix that trivially: just make the "nop"
instruction we jam into here have the right type. That way, the leftover
field/element pointer instructions are perfectly valid, but still
unused.
This is redundant because `storePtr2` will coerce to the return type
which (in `Sema.coerceInMemoryAllowedErrorSets`) will add errors to the
current function's IES if necessary.
This logic predates certain Sema enhancements whose behavior it
essentially tries to emulate in one specific case in a problematic way.
In particular, this logic handled initializing comptime-known `const`s
through RLS, which was reworked a few years back in 644041b to not rely
on this logic, and catching runtime fields in comptime-only
initializers, which has since been *correctly* fixed with better checks
in `Sema.storePtr2`. That made the highly complex logic in
`validateStructInit`, `validateUnionInit`, and `zirValidatePtrArrayInit`
entirely redundant. Worse, it was also causing some tracked bugs, as
well as a bug which I have identified and fixed in this PR (a
corresponding behavior test is added).
This commit simplifies union initialization by bringing the runtime
logic more in line with the comptime logic: the tag is now always
populated by `Sema.unionFieldPtr` based on `initializing`, where this
previously happened only in the comptime case (with `validateUnionInit`
instead handling it in the runtime case). Notably, this means that
backends are now able to consider getting a pointer to an inactive union
field as Illegal Behavior, because the `set_union_tag` instruction now
appears *before* the `struct_field_ptr` instruction as you would
probably expect it to.
Resolves: #24520Resolves: #24595
This passes tests but it doesn't provide as big a window size as is
required to decompress larger streams.
The next commit in this branch will work towards that, without
introducing an additional buffer.
- factor out `loadReg`
- support all general system control registers in inline asm
- fix asserts after iterating field offsets
- fix typo in `slice_elem_val`
- fix translation of argument locations
This option never worked properly (it emitted wrongly-formatted code),
and it doesn't seem particularly *useful* -- someone who's proficient
enough with `std.Build` to not need explanations probably just wants to
write their own thing. Meanwhile, the use case of writing your own
`build.zig` was extremely poorly served, because `build.zig.zon` *needs*
to be generated programmatically for a correct `fingerprint`, but the
only ways to do that were to a) do it wrong and get an error, or b) get
the full init template and delete the vast majority of it. Both of these
were pretty clunky, and `-s` didn't really help.
So, replace this flag with a new one, `--minimal`/`-m`, which uses a
different template. This template is trivial enough that I opted to just
hardcode it into the compiler for simplicity. The main job of
`zig init -m` is to generate a correct `build.zig.zon` (if it is unable
to do this, it exits with a fatal error). In addition, it will *attempt*
to generate a tiny stub `build.zig`, with only an `std` import and an
empty `pub fn build`. However, if `build.zig` already exists, it will
avoid overwriting it, and doesn't even complain. This serves the use
case of writing `build.zig` manually and *then* running `zig init -m`
to generate an appropriate `build.zig.zon`.
