Legacy anon decls now have three uses:
* Type owner decls
* Function owner decls
* `@export` and `@extern`
Therefore, there are no longer any cases where we wish to explicitly
omit legacy anon decls from the binary. This means we can remove the
concept of an "alive" vs "dead" `Decl`, which also allows us to remove
the separate `anon_work_queue` in `Compilation`.
Good riddance!
Most of these changes are trivial. There's a fix for a minor bug this
exposed in `Value.readFromPackedMemory`, but aside from that, it's all
just things like changing `intern` calls to `toIntern`.
Perhaps someday, we will make Sema operate on mutable values more
generally. For now, it makes sense to split out this representation,
since it is only used in comptime pointer accesses.
There are some currently unused methods on `MutableValue` which will
be used once I rewrite the comptime pointer access logic to be less
terrible.
The commit following this one will - at long last - delete the legacy
Value representation
`Decl` can no longer store un-interned values, so this field is now
unnecessary. The type can instead be fetched with the new `typeOf`
helper method, which just gets the type of the Decl's `Value`.
This commit changes how we represent comptime-mutable memory
(`comptime var`) in the compiler in order to implement the intended
behavior that references to such memory can only exist at comptime.
It does *not* clean up the representation of mutable values, improve the
representation of comptime-known pointers, or fix the many bugs in the
comptime pointer access code. These will be future enhancements.
Comptime memory lives for the duration of a single Sema, and is not
permitted to escape that one analysis, either by becoming runtime-known
or by becoming comptime-known to other analyses. These restrictions mean
that we can represent comptime allocations not via Decl, but with state
local to Sema - specifically, the new `Sema.comptime_allocs` field. All
comptime-mutable allocations, as well as any comptime-known const allocs
containing references to such memory, live in here. This allows for
relatively fast checking of whether a value references any
comptime-mtuable memory, since we need only traverse values up to
pointers: pointers to Decls can never reference comptime-mutable memory,
and pointers into `Sema.comptime_allocs` always do.
This change exposed some faulty pointer access logic in `Value.zig`.
I've fixed the important cases, but there are some TODOs I've put in
which are definitely possible to hit with sufficiently esoteric code. I
plan to resolve these by auditing all direct accesses to pointers (most
of them ought to use Sema to perform the pointer access!), but for now
this is sufficient for all realistic code and to get tests passing.
This change eliminates `Zcu.tmp_hack_arena`, instead using the Sema
arena for comptime memory mutations, which is possible since comptime
memory is now local to the current Sema.
This change should allow `Decl` to store only an `InternPool.Index`
rather than a full-blown `ty: Type, val: Value`. This commit does not
perform this refactor.
A pointer type already has an alignment, so this information does not
need to be duplicated on the function type. This already has precedence
with addrspace which is already disallowed on function types for this
reason. Also fixes `@TypeOf(&func)` to have the correct addrspace and
alignment.
See comment. This slightly regresses a previous fix from this branch. A
proper solution will come soon, with the splitting up of `Decl` into
`Cau` and `Nav`.
This makes tracking easier across incremental updates: `scanDecl` can
now tell whether an existing decl in a namespace was mapped to the one
it's analyzing in the new ZIR.
There is no reason to perform this detection during semantic analysis.
In fact, doing so is problematic, because we wish to utilize detection
of existing decls in a namespace in incremental compilation.
This implements the accepted proposal #18816. Namespace-owning types
(struct, enum, union, opaque) are no longer unique whenever analysed;
instead, their identity is determined based on their AST node and the
set of values they capture.
Reified types (`@Type`) are deduplicated based on the structure of the
type created. For instance, if two structs are created by the same
reification with identical fields, layout, etc, they will be the same
type.
This commit does not produce a working compiler; the next commit, adding
captures for decl references, is necessary. It felt appropriate to split
this up.
Resolves: #18816
Namespace types (`struct`, `enum`, `union`, `opaque`) do not use
structural equality - equivalence is based on their Decl index (and soon
will change to AST node + captures). However, we previously stored all
other information in the corresponding `InternPool.Key` anyway. For
logical consistency, it makes sense to have the key only be the true key
(that is, the Decl index) and to load all other data through another
function. This introduces those functions, by the name of
`loadStructType` etc. It's a big diff, but most of it is no-brainer
changes.
In future, it might be nice to eliminate a bunch of the loaded state in
favour of accessor functions on the `LoadedXyzType` types (like how we
have `LoadedUnionType.size()`), but that can be explored at a later
date.
This changes the representation of closures in Zir and Sema. Rather than
a pair of instructions `closure_capture` and `closure_get`, the system
now works as follows:
* Each ZIR type declaration (`struct_decl` etc) contains a list of
captures in the form of ZIR indices (or, for efficiency, direct
references to parent captures). This is an ordered list; indexes into
it are used to refer to captured values.
* The `extended(closure_get)` ZIR instruction refers to a value in this
list via a 16-bit index (limiting this index to 16 bits allows us to
store this in `extended`).
* `Module.Namespace` has a new field `captures` which contains the list
of values captured in a given namespace. This is initialized based on
the ZIR capture list whenever a type declaration is analyzed.
This change eliminates `CaptureScope` from semantic analysis, which is a
nice simplification; but the main motivation here is that this change is
a prerequisite for #18816.
* Introduce `-Ddebug-extensions` for enabling compiler debug helpers
* Replace safety mode checks with `std.debug.runtime_safety`
* Replace debugger helper checks with `!builtin.strip_debug_info`
Sometimes, you just have to debug optimized compilers...
The signature and variants of Sema's main loop have evolved over time to
what was a quite confusing state of affairs. This commit makes minor
changes to how `analyzeBodyInner` works, and restructures/renames the
wrapper functions, adding doc comments to clarify their purposes. The
most notable change is that `analyzeBodyInner` now returns
`CompileError!void`; inline breaks are now all communicated via
`error.ComptimeBreak`.
* make test names contain the fully qualified name
* make test filters match the fully qualified name
* allow multiple test filters, where a test is skipped if it does not
match any of the specified filters
Windows paths now use WTF-16 <-> WTF-8 conversion everywhere, which is lossless. Previously, conversion of ill-formed UTF-16 paths would either fail or invoke illegal behavior.
WASI paths must be valid UTF-8, and the relevant function calls have been updated to handle the possibility of failure due to paths not being encoded/encodable as valid UTF-8.
Closes#18694Closes#1774Closes#2565
If an adapted string key with embedded nulls was put in a hash map with
`std.hash_map.StringIndexAdapter`, then an incorrect hash would be
entered for that entry such that it is possible that when looking for
the exact key that matches the prefix of the original key up to the
first null would sometimes match this entry due to hash collisions and
sometimes not if performed later after a grow + rehash, causing the same
key to exist with two different indices breaking every string equality
comparison ever, for example claiming that a container type doesn't
contain a field because the field name string in the struct and the
string representing the identifier to lookup might be equal strings but
have different string indices. This could maybe be fixed by changing
`std.hash_map.StringIndexAdapter.hash` to only hash up to the first
null, therefore ensuring that the entry's hash is correct and that all
future lookups will be consistent, but I don't trust anything so instead
I assert that there are no embedded nulls.
When coercing the operand of a `ret_node` etc instruction, the source
location for errors used to point to the entire `return` statement.
Instead, we now point to the operand, as would be expected if there was
an explicit `as_node` instruction (like there used to be).
This logic (currently) has a non-trivial cost (particularly in terms of
peak RSS) for tracking dependencies. Until incremental compilation is in
use in the wild, it doesn't make sense for users to pay that cost.
* Functions failing codegen now set this failure on the function
analysis state. Decl analysis `codegen_failure` is reserved for
failures generating constant values.
* `liveness_failure` is consolidated into `codegen_failure`, as we do
not need to distinguish these, and Liveness.Verify is just a debugging
feature anyway.
* `sema_failure_retryable` and `codegen_failure_retryable` are removed.
Instead, retryable failures are recorded in the new
`Zcu.retryable_failures` list. On an incremental update, this list is
flushed, and all elements are marked as outdated so that we re-attempt
analysis and code generation.
Also remove the `generation` fields from `Zcu` and `Decl` as these are
not needed by our new strategy for incremental updates.
* Mark root Decls for re-analysis separately
* Check for re-analysis of root Decls
* Remove `outdated` entry when analyzing fn body
* Remove legacy `outdated` field from Decl analysis state
* Invalidate `decl_val` dependencies
* Recursively mark and un-mark all dependencies correctly
* Queue analysis of outdated dependers in `Compilation.performAllTheWork`
Introduces logic to invalidate `decl_val` dependencies after
`Zcu.semaDecl` completes. Also, recursively un-mark dependencies as PO
where needed.
With this, all dependency invalidation logic is in place. The next step
is analyzing outdated dependencies and triggering appropriate
re-analysis.
Sema now tracks dependencies appropriately. Early logic in Zcu for
resolving outdated decls/functions is in place. The setup used does not
support `usingnamespace`; compilations using this construct are not yet
supported by this incremental compilation model.
