[Lldb-commits] [PATCH] D55575: [NativePDB] Support local variables

[Zachary Turner via Phabricator via lldb-commits]

zturner created this revision.
zturner added reviewers: labath, lemo, aleksandr.urakov, amccarth, clayborg, leonid.mashinskiy.
Herald added subscribers: JDevlieghere, aprantl.

This patch adds support for parsing and evaluating local variables. using the native pdb plugin.

While implementing this, I came up with several new ideas for increasing test coverage throughout LLDB (not limited to this plugin), including:

- We should start extending AST tests to other types of targets and debug info, not just windows / native pdb.  This uncovered a few bugs for me here that allowed me to proceed.
- We should have comprehensive test coverage of the DWARFExpression evaluator in lldb/Expression/DWARFExpression.cpp.  This would allow us to improve test coverage of scenarios that require compilers to emit specific debug info, and allow us to do it in a way that doesn't require that debug info to have been emitted by some compiler.
- We should add options to `lldb-test` that will allow it to call into `SymbolFile::ResolveSymbolContext` and dump the output in some format that is interesting for file checking.  This function is at the heart of a lot of logic, and if it doesn't work, many things will fail.  Being able to test all of the edge cases of this function would weed out a lot of problems.

Anyway, for now these are all just ideas.  For this patch, I've just implemented support for local variables and a test to make sure it works.  One interesting thing: With the old PDB plugin, this test takes over 1 minute to run.  With the new PDB plugin, it takes about 2 seconds.


https://reviews.llvm.org/D55575

Files:
  lldb/lit/SymbolFile/NativePDB/Inputs/local-variables.lldbinit
  lldb/lit/SymbolFile/NativePDB/local-variables.cpp
  lldb/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
  lldb/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.h
  lldb/source/Plugins/SymbolFile/NativePDB/PdbSymUid.h
  lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
  lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
  lldb/source/Symbol/ClangASTContext.cpp
  llvm/include/llvm/Support/BinaryStreamArray.h

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