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`.
This commit also performs some refactors to `TypedValue.print` in
preparation for improved comptime pointer access logic. Once that logic
exists, `TypedValue.print` can use Sema to access pointers for more
helpful printing.
This commit also implements proposal #19435, because the existing logic
there relied on some blatantly incorrect code in `Value.sliceLen`.
Resolves: #19435
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 issue was causing debug information to sometimes not function
correctly for some local variables, with debuggers simply reporting that
the variable does not exist. What was happening was that after an AIR
body - and thus debug lexical scope - begins, but before any `dbg_stmt`
within it, the `scope` on `self.wip.debug_location` refers to the parent
scope, but the `scope` field on the `DILocalVariable` metadata passed to
`@llvm.dbg.declare` points, correctly, to the nested scope. I haven't
looked into precisely what happens here, but in short, it would appear
that LLVM Doesn't Like It (tm).
The fix is simple: when we change `self.scope` at the start or end of an
AIR body, also modify the scope on `self.wip.debug_location`. This is
correct as we always want the debug info for an instruction to be
associated with the block it is within, even if the line/column are
slightly outdated for any reason.
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.
When the slice-by-length start position is runtime-known, it is likely
protected by a runtime-known condition and therefore a compile error is
less appropriate than a runtime panic check.
This is demonstrated in the json code that was updated and then reverted
in this commit.
When #3806 is implemented, this decision can be reassessed.
Revert "std: work around compiler unable to evaluate condition at compile time"
Revert "frontend: comptime array slice-by-length OOB detection"
This reverts commit 7741aca96c8cc6df7e8c4bd10ada741d6a3ffb9d.
This reverts commit 2583b389eaf5f7aaa0eb79b51126506c1e172d15.
This fixes an issue with boostrapping the compiler using MSVC. There is a CircularBuffer with
an array of length 65536 initialized to undefined, and because the undefined path of `renderValue`
was using `StringLiteral` to render this, the resulting zig2.c would fail to compile using MSVC.
The solution was to move the already-existing array initializer path (used in the non-undefined path)
into StringLiteral, and make StringLiteral aware of the total length so it could decide between which
style of initialization to use. We prefer to use string literals if we can, as this results in the least
amount of emitted C source.
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.
Closes https://github.com/ziglang/zig/issues/19284
As of 9f2cb920c055bc990cc9d593b8dc9eaa450d07b9 configuring the global
cache directory to a relative path causes errors of the following form
when cross compiling to `windows-gnu`.
```
error: unable to generate DLL import .lib file for kernel32: FileNotFound
```
The issue occurred because the `def_final_path` included the global
cache path as a prefix and later on the `def_final_file` was created
using that path with the global cache directory handle.
