There is no way to know the expected parent pointer attributes (most
notably alignment) from the type of the field pointer, so provide them
in the first argument.
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
This test has regressed due to a bug in the self-hosted COFF linker.
Jakub recommended disabling it for now, since the COFF linker is being
effectively rewritten, so there is little point in fixing the bug now.
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.
This fixes a bug where, at least with the LLVM backend, `@extern` calls
which had the same name as a normal `extern` in the same Zcu would
result in the `@extern` incorrectly suffixing the identifier `.2`.
Usually, the LLVM backend has a system to change the generated globals
to "collapse" them all together, but it only works if `updateDecl` is
called!
