C++ IR: Support for global virtual dispatch #2638
Merged
Conversation
This file contains hidden or 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
The IR data flow library now supports virtual dispatch with a library that's similar to `security.TaintTracking`. In particular, it should have the same performance characteristics. The main difference is that non-recursive callers of `flowsFrom` now pass `_` instead of `true` for `boolean allowFromArg`. This change allows flow through `return` to actually work.
Contributor
Author
|
Performance is good on MySQL and facebookincubator/fizz. There's a lot of room for optimisation, but I'd like to find a database with bad performance before optimising. |
geoffw0
reviewed
Jan 17, 2020
Contributor
geoffw0
left a comment
geoffw0
left a comment
There was a problem hiding this comment.
I'm pretty happy with this. I've asked a few questions to check my understanding.
I'd like to find a database with bad performance before optimising.
Yes - I imagine in many projects there just won't be enough DataSensitiveCalls for performance issues to manifest. Perhaps run select count(DataSensitiveCall dsc) on LGTM and see which projects come up top?
cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowDispatch.qll
Outdated
Show resolved
Hide resolved
geoffw0
reviewed
Jan 17, 2020
Merged
Better clarity was requested in the PR review.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.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.
The IR data flow library now supports virtual dispatch with a library that's similar to
security.TaintTracking. In particular, it should have the same performance characteristics. The main difference is that non-recursive callers offlowsFromnow pass_instead oftrueforboolean allowFromArg. This change allows flow throughreturnto actually work.