add 'fn write_u16s' to Memory #70397
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
(rust_highfive has picked a reviewer for you, use r? to override) |
rust-highfive
added
the
S-waiting-on-review
|
r? @RalfJung |
4 tasks
RalfJung
reviewed
Mar 25, 2020
src/librustc_mir/interpret/memory.rs
Outdated
Comment on lines
837
to
838
| let size = Size::from_bytes(src.size_hint().0 as u64); | ||
| let size = Size::from_bytes(u64::try_from(src.size_hint().0).unwrap()); |
There was a problem hiding this comment.
Good thought, but I already took care of that in #70226 so this will just cause merge conflict. Better to not do this change.
RalfJung
reviewed
Mar 25, 2020
src/librustc_mir/interpret/memory.rs
Outdated
Comment on lines
857
to
858
| assert!(src.size_hint().1.is_some()); // Check that the iterator has an upper bound. | ||
| let size = Size::from_bytes(u64::try_from(src.size_hint().0).unwrap()); |
There was a problem hiding this comment.
Please don't call size_hint twice.
There was a problem hiding this comment.
The following snippet copied from here does the right thing:
let (lower, upper) = src.size_hint();
let len = upper.expect("can only write bounded iterators");
assert_eq!(lower, len, "can only write iterators with a precise length");
RalfJung
reviewed
Mar 25, 2020
src/librustc_mir/interpret/memory.rs
Outdated
| let size = Size::from_bytes(u64::try_from(src.size_hint().0).unwrap()); | ||
| let ptr = match self.check_ptr_access(ptr, size, Align::from_bytes(2).unwrap())? { | ||
| Some(ptr) => ptr, | ||
| None => return Ok(()), // zero-sized access |
There was a problem hiding this comment.
Hm... in this case we fail to check that the iterator is truly empty. And write_bytes above has the same bug in fact.
There was a problem hiding this comment.
The check that is needed here is something like
src.next().expect_none("iterator said it was empty but returned an element")
RalfJung
reviewed
Mar 25, 2020
src/librustc_mir/interpret/memory.rs
Outdated
| let tcx = self.tcx.tcx; | ||
| let allocation = self.get_raw_mut(ptr.alloc_id)?; | ||
|
|
||
| for (idx, item) in src.enumerate() { |
There was a problem hiding this comment.
This fails to check that the size_hint did not lie.
I think it is better to loop up to len and make sure the iterator did not lie:
for idx in 0..len {
let val = Scalar::from_u16(src.next().unwrap());
...
}
|
The job Click to expand the log.I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact |
|
Please rebase, a PR just landed that conflicts with this one. |
|
☔ The latest upstream changes (presumably #70404) made this pull request unmergeable. Please resolve the merge conflicts. |
RalfJung
reviewed
Mar 26, 2020
src/librustc_mir/interpret/memory.rs
Outdated
Comment on lines
881
to
884
| } | ||
| Ok(()) |
There was a problem hiding this comment.
After the loop, please make sure that the iterator is empty like here.
RalfJung
reviewed
Mar 26, 2020
src/librustc_mir/interpret/memory.rs
Outdated
| let val = Scalar::from_u16( | ||
| src.next().expect("iterator was shorter than it said it would be"), | ||
| ); | ||
| let offset_ptr = ptr.offset(Size::from_bytes(idx.checked_mul(2).unwrap()), &tcx)?; |
There was a problem hiding this comment.
Suggested change
| let offset_ptr = ptr.offset(Size::from_bytes(idx.checked_mul(2).unwrap()), &tcx)?; | |
| let offset_ptr = ptr.offset(Size::from_bytes(idx) * 2, &tcx)?; // `Size` multiplication |
RalfJung
approved these changes
Mar 26, 2020
|
I force-pushed the squashed commit. Thank you for all the reviews! 😸 |
|
@bors r+ |
|
📌 Commit 4538f89 has been approved by |
bors
added
S-waiting-on-bors
Dylan-DPC-zz
pushed a commit
to Dylan-DPC-zz/rust
that referenced
this pull request
Mar 26, 2020
add 'fn write_u16s' to Memory Added new function `Memory::write_u16s`. Needed in `MIRI` for implementing helper function to write wide_str to memory (for Windows).
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Mar 26, 2020
Rollup of 6 pull requests Successful merges: - rust-lang#70384 (Refactor object file handling) - rust-lang#70397 (add 'fn write_u16s' to Memory) - rust-lang#70413 (Fix incorrect pattern warning "unreachable pattern") - rust-lang#70428 (`error_bad_item_kind`: add help text) - rust-lang#70429 (Clean up E0459 explanation) - rust-lang#70437 (Miri float->int casts: be explicit that this is saturating) Failed merges: r? @ghost
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Added new function
Memory::write_u16s. Needed inMIRIfor implementing helper function to write wide_str to memory (for Windows).