Fix DWARF void return type confidence#7888
Open
gamozolabs wants to merge 1 commit intoVector35:devfrom
Open
Conversation
Previously, functions with missing DW_AT_type (void return) were assigned confidence 0, allowing Binary Ninja's analysis to override them with incorrect inferred types (e.g., uint64_t). Per DWARF spec section 3.3.2, a missing DW_AT_type on a subprogram means void, not "unknown". However, with minimal debug info (-g1), types are omitted entirely, so we can't distinguish void from unknown. This fix: - Uses MAX_CONFIDENCE for explicit return types (was 128), matching parameter confidence for consistency - Uses MAX_CONFIDENCE for void when full debug info is present (detected by checking if any type definitions exist in the compilation unit) - Keeps confidence 0 for minimal debug info (-g1) to allow analysis to infer Tested with C (-g1, -g2) and C++ (-g1, -g2) code to verify correct behavior across debug levels and languages (C uses DW_AT_prototyped, C++ doesn't). Co-Authored-By: Claude Opus 4.5 <[email protected]>
|
|
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Previously, functions with missing DW_AT_type (void return) were assigned confidence 0, allowing Binary Ninja's analysis to override them with incorrect inferred types (e.g., uint64_t).
Per DWARF spec section 3.3.2, a missing DW_AT_type on a subprogram means void, not "unknown". However, with minimal debug info (-g1), types are omitted entirely, so we can't distinguish void from unknown.
This fix:
Tested with C (-g1, -g2) and C++ (-g1, -g2) code to verify correct behavior across debug levels and languages (C uses DW_AT_prototyped, C++ doesn't).
Here's the before and after (TL;DR: void applies from dwarf debug info now)
After