Fix the following warning from Rust 1.35:
warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
--> wasmtime-runtime/src/instance.rs:473:25
|
465 | } else if let Some(start_export) = self.module.exports.get("_start") {
| ----------- immutable borrow occurs here
...
473 | self.invoke_function(*func_index)
| ^^^^ ----------- immutable borrow later used here
| |
| mutable borrow occurs here
|
= note: #[warn(mutable_borrow_reservation_conflict)] on by default
= warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
= note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
This follows the rest of the code base data structures, where we have a
mutable data structure builder; once the data structure is constructed,
it's immutable.
This also makes the definition of instructions easier, and it paves the
way for defining immediate variants.
This is also https://bugzilla.mozilla.org/show_bug.cgi?id=1552737.
Cranelift currently has a tendency to create redundant copies (self-copies) of
values from a stack slot back to the same stack slot. This generates a
pointless load and store and an unnecessary register use. The copies are
created by `visit_inst` in regalloc/reload.rs. They appear to occur mostly,
but not exclusively, at loop heads. It's unclear why this happens.
This patch adds a special case to `visit_inst` to find such copies. They are
converted into a new instruction, `copy_nop`, which takes and produces the
same SSA names, so as not to break any of the SSA invariants, but which has a
zero-length encoding, hence removing the copy at emission time.
`copy_nop`s source and destination operands must be stack slots and of course
the *same* stack slot. The verifier has been enhanced to check this, since
misuse of `copy_nop` will likely lead to hard-to-find incorrect-code bugs.
Attempts were made to write a standalone .clif test case. But these failed
because it appears the .clif parser accepts but ignores location hints that
are stack slots. So it's impossible to write, in clif, the exact form of
`copy` instruction that triggers the transformation.
Linux's open returns ENOTDIR when used with O_DIRECTORY|O_NOFOLLOW and
the path is a symlink. Update the code to expect this.
FreeBSD's open returns EMLINK instead of ELOOP when using O_NOFOLLOW on
symlink. Update the code to expect this.
WASI currently lacks the ability to specify the full UNIX access control
information when creating files and directories, so for now just avoid
creating executable files and rely on the umask.
If a path_open call is requesting __WASI_RIGHT_FD_FILESTAT_SET_SIZE,
interpret that as a request for write privleges. If it is requesting
O_TRUNC, require __WASI_RIGHT_PATH_FILESTAT_SET_SIZE, since this is
a path operation rather than a FD operation.
This adds test cases to ensure, to a reasonably high degree of certainty, that
the magic-number generators `magic_u32`, `magic_s32`, `magic_u64` and
`magic_s64` work correctly. This is done by iterating through a large number
of `(n, d)` pairs, generating the magic numbers for `d`, interpreting the
magic numbers so as to perform the division, and comparing against the result
produced directly by the hardware. The distribution of numbers is arranged so
that particular emphasis is given to corner cases -- the range ends and
midpoints -- but also so that there is at least some cover for values away
from those areas. In total 50,148,000 tests are performed.
