[pointer][invariant] Remove AliasingMapping, Inaccessible #1942
+4
−52
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
This was referenced Oct 18, 2024
jswrenn
approved these changes
Oct 18, 2024
Codecov ReportAll modified and coverable lines are covered by tests ✅
Additional details and impacted files@@ Coverage Diff @@
## Ifc49755af0d90eeefe7822d755d508403c266bda #1942 +/- ##
==========================================================================
Coverage 89.46% 89.46%
==========================================================================
Files 17 17
Lines 5838 5838
==========================================================================
Hits 5223 5223
Misses 615 615 ☔ View full report in Codecov by Sentry. |
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
2 times, most recently
from
53deb0a
to
4795dcd
Compare
joshlf
changed the title
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
4795dcd
to
94165e5
Compare
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
2 times, most recently
from
03ccfe5
to
244bef4
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
94165e5
to
dbf871e
Compare
This was referenced Oct 22, 2024
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
244bef4
to
5f1d243
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
dbf871e
to
33fc89f
Compare
This was referenced Oct 23, 2024
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
5f1d243
to
995e1f0
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
33fc89f
to
48f1450
Compare
We previously used `AliasingMapping`s and `Inaccessible` to model `UnsafeCell` agreement. This abuses the notion of a mapping since one doesn't ever actually want to change the aliasing of a pointer (and certainly not to `Inaccessible`) - really this was meant to model pointer casts which should never be performed. In addition to being an awkward fit, the presence of `Inaccessible` meant that code could not assume that any `Aliasing` invariant permitted reading, and so we had to add extra machinery to work around this. Future commits will use a different, simpler model for denoting `UnsafeCell` agreement or disagreement. While we're here, make `Read` slightly more permissive, implemented for `A: Aliasing, T: Immutable` rather than just `A: Reference, T: Immutable`. Makes progress on #1122, #1866 gherrit-pr-id: I1ac2ae177a235083e33b09fc848423220d3da042
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
995e1f0
to
4f292ed
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
48f1450
to
355531d
Compare
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.
We previously used
AliasingMappings andInaccessibleto modelUnsafeCellagreement. This abuses the notion of a mapping since onedoesn't ever actually want to change the aliasing of a pointer (and
certainly not to
Inaccessible) - really this was meant to modelpointer casts which should never be performed. In addition to being an
awkward fit, the presence of
Inaccessiblemeant that code could notassume that any
Aliasinginvariant permitted reading, and so we had toadd extra machinery to work around this.
Future commits will use a different, simpler model for denoting
UnsafeCellagreement or disagreement.While we're here, make
Readslightly more permissive, implemented forA: Aliasing, T: Immutablerather than justA: Reference, T: Immutable.Makes progress on #1122, #1866
This PR is on branch ptr-overhaul-more-generic-issue-1945.