It is problematic for the cached `InternPool` state to directly
reference ZIR instruction indices, as these are not stable across
incremental updates. The existing ZIR mapping logic attempts to handle
this by iterating the existing Decl graph for a file after `AstGen` and
update ZIR indices on `Decl`s, struct types, etc. However, this is
unreliable due to generic instantiations, and relies on specialized
logic for everything which may refer to a ZIR instruction (e.g. a
struct's owner decl). I therefore determined that a prerequisite change
for incremental compilation would be to rework how we store these
indices.
This commit introduces a `TrackedInst` type which provides a stable
index (`TrackedInst.Index`) for a single ZIR instruction in the
compilation. The `InternPool` now stores these values in place of ZIR
instruction indices. This makes the ZIR mapping logic relatively
trivial: after `AstGen` completes, we simply iterate all `TrackedInst`
values and update those indices which have changed. In future, if the
corresponding ZIR instruction has been removed, we must also invalidate
any dependencies on this instruction to trigger any required
re-analysis, however the dependency system does not yet exist.
This commit changes how declarations (`const`, `fn`, `usingnamespace`,
etc) are represented in ZIR. Previously, these were represented in the
container type's extra data (e.g. as trailing data on a `struct_decl`).
However, this introduced the complexity of the ZIR mapping logic having
to also correlate some ZIR extra data indices. That isn't really a
problem today, but it's tricky for the introduction of `TrackedInst` in
the commit following this one. Instead, these type declarations now
simply contain a trailing list of ZIR indices to `declaration`
instructions, which directly encode all data related to the declaration
(including containing the declaration's body). Additionally, the ZIR for
`align` etc have been split out into their own bodies. This is not
strictly necessary, but it's much simpler to understand for an
insignificant cost in bytes, and will simplify the resolution of #131
(where we may need to evaluate the pointer type, including align etc,
without immediately evaluating the value body).
During semantic analysis the value may be an unresolved lazy value
which makes using `toUnsignedInt` invalid.
Add assertions to detect similar issues in the future.
Closes#18624
This logic was previously in Sema, which was unnecessary complexity, and meant the issue was not detected unless the declaration was semantically analyzed. This commit finishes the work which 941090d started.
Resolves: #17916
Previously `@as(i64, undefined) +% 1` would produce `@as(@TypeOf(undefined), undefined)` which now gives `@as(i64, undefined)`.
Previously `@as(i64, undefined) +| 1` would hit an assertion which now gives `@as(i64, undefined)`.
This reverts commit d9d840a33ac8abb0e616de862f592821a7f4a35e, reversing
changes made to a04d4330945565b8d6f298ace993f6954c42d0f3.
This is not an adequate implementation of the missing safety check, as
evidenced by the changes to std.json that are reverted in this commit.
Reopens#18382Closes#18510
Changes the types of `std.builtin.Type` `name` fields from `[]const u8`
to `[:0]const u8`, which should make them easier to pass to C APIs
expecting null-terminated strings.
This will break code that reifies types using `[]const u8` strings, such
as code that uses `std.mem.tokenize()` to construct types from strings
at comptime. Luckily, the fix is simple: simply concatenate the
`[]const u8` string with an empty string literal (`name ++ ""`) to
explicitly coerce it to `[:0]const u8`.
Co-authored-by: Krzysztof Wolicki <der.teufel.mail@gmail.com>
Updated `zirShl`, to compute `shl_exact` with `comptime_int` LHS operand
like `shl`, and added test case for `@shlExact` with `comptime_int` LHS
operand.
Instead of making its own inside create. 10 out of 10 calls to create()
had already an arena in scope, so this commit means that 10 instances of
Compilation now reuse an existing arena with the same lifetime rather
than creating a redundant one.
In other words, this very slightly optimizes initialization of the
frontend in terms of memory allocation.
