[NLL] remove "constant" region variables, report free region errors later #14
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
nikomatsakis
force-pushed
the
nll-delay-free-region-error
branch
from
2c779e2 to
7ff5f1c
Compare
nikomatsakis
changed the title
nikomatsakis
force-pushed
the
nll-master
branch
from
c93dd18 to
74e1192
Compare
It will be useful later for diagnostics to be able to remember where things were live.
Rather than declaring some region variables to be constant, and reporting errors when they would have to change, we instead populate each free region X with a minimal set of points (the CFG plus end(X)), and then we let inference do its thing. This may add other `end(Y)` points into X; we can then check after the fact that indeed `X: Y` holds. This requires a bit of "blame" detection to find where the bad constraint came from: we are currently using a pretty dumb algorithm. Good place for later expansion.
nikomatsakis
force-pushed
the
nll-delay-free-region-error
branch
from
7ff5f1c to
bdf0b89
Compare
nikomatsakis
pushed a commit
that referenced
this pull request
Sep 12, 2019
vxWorks: set DEFAULT_MIN_STACK_SIZE to 256K and use min_stack to pass initial stack size to rtpSpawn
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Outdated suggestions cannot be applied.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.
This was rust-lang#45911:
Rather than declaring some region variables to be constant, and reporting errors when they would have to change, we instead populate each free region X with a minimal set of points (the CFG plus end(X)), and then we let inference do its thing. This may add other end(Y) points into X; we can then check after the fact that indeed X: Y holds.
This will be useful when handling closures properly, since we can then propagate some of those constraints in the form of WF-conditions to our creator. This PR doesn't handle any of that yet.
This requires a bit of "blame" detection to find where the bad constraint came from: we are currently using a pretty dumb algorithm. Good place for later expansion.