[PATCH] D151353: [DebugInfo] Add error-handling to DWARFAbbreviationDeclarationSet

[Alex Langford via Phabricator via llvm-commits]

bulbazord marked an inline comment as done.
bulbazord added a comment.

Ok, the pre-submission checks failing are actually due to this change. Specifically, parsing the `debug_abbrev` section of the objects produced by these tests leads to an infinite loop. It goes as follows:

- We fail to get an ULEB128 value for the code because the contents of the debug_abbrev are invalid. The DataExtractor thus returns 0, signaling to the DWARFAbbreviationDeclaration parsing code that were done with this DWARFAbbreviationDeclaration.
- The DWARFAbbreviationDeclarationSet sees it's done and returns an empty Set to the DWARFDebugAbbrev parsing code. The offset is still at 0, so it's still technically a valid offset for the DataExtractor. So we continue on...

I believe `DWARFDebugAbbrev::parse` was relying on knowing when it's done by checking if the offset has moved. Otherwise we end up in an infinite loop. I'm going to add some additional safety checks, but it shouldn't be significant. I'll request another review after adding it.


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D151353