[PATCH] D73961: [LLDB] Addresses can be two bytes in size

[Ayke via Phabricator via llvm-commits]

aykevl created this revision.
aykevl added reviewers: granata.enrico, labath, dylanmckay, Andrzej.
Herald added subscribers: llvm-commits, lldb-commits, hiraditya.
Herald added projects: LLDB, LLVM.

Addresses are usually two bytes in size on AVR, so make sure LLDB deals with that.

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I'm not sure I caught all cases. In particular, lldb/include/lldb/DataFormatters/FormattersHelpers.h might be related but I've left it alone as it didn't seem to be necessary.

Honestly I think LLDB would become a lot more forgiving to uncommon architectures when these asserts are removed and avoids assumptions based on the address size. When the address size is relevant (for example, to read a value from memory), it should have an exhaustive test with a default case that does an assert (for easy debugging). For example:

  switch (addr_size) {
  case 4:
      // do one thing
  case 8:
      // do something else
  default:
      assert(false && "unknown addr_size");
  }

This way, it's easy to find the places that make these assumptions just by following the asserts.

I'm not sure how to add a test for this. I can test it locally by connecting to a remote debugger (simavr <https://github.com/buserror/simavr>). However, I don't know how to do something like that in the LLDB testing framework. Additionally, for that to work I only needed the change in DumpDataExtractor.cpp so I'm not sure how to exhaustively test this.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73961

Files:
  lldb/source/Core/DumpDataExtractor.cpp
  lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugArangeSet.cpp
  lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
  lldb/source/Symbol/DWARFCallFrameInfo.cpp
  lldb/source/Utility/DataExtractor.cpp
  llvm/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp

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