propagate "uses reflection" through SSA stores #783
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
Up until now, the new SSA reflection detection relied on call sites
to propagate which objects (named types, struct fields) used reflection.
For example, given the code:
json.Marshal(new(T))
we would first record that json.Marshal calls reflect.TypeOf,
and then that the user's code called json.Marshal with the type *T.
However, this would not catch a slight variation on the above:
var t T
reflect.TypeOf(t)
t.foo = struct{bar int}{}
Here, type T's fields such as "foo" and "bar" are not obfuscated,
since our logic sees the call site and marks the type T recursively.
However, the unnamed `struct{bar int}` type was still obfuscated,
causing errors such as:
cannot use struct{uKGvcJvD24 int}{} (value of type struct{uKGvcJvD24 int}) as struct{bar int} value in assignment
The solution is to teach the analysis about *ssa.Store instructions
in a similar way to how it already knows about *ssa.Call instructions.
If we see a store where the destination type is marked for reflection,
then we mark the source type as well, fixing the bug above.
This fixes obfuscating github.com/gogo/protobuf/proto.
A number of other Go modules fail with similar errors,
and they look like very similar bugs,
but this particular fix doesn't apply to them.
Future incremental fixes will try to deal with those extra cases.
Fixes burrowers#685.
pagran
approved these changes
Aug 2, 2023
lu4p
approved these changes
Aug 2, 2023
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Outdated suggestions cannot be applied.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.
(see commit message)
Fixes #685.