[Lldb-commits] [PATCH] D97739: Add a progress class that can track and report long running operations that happen in LLDB.

Mon Mar 1 15:45:32 PST 2021

clayborg added a comment.

The current Progress class allows users to specify how many items are to be done when they construct a lldb_private::Progress object, but this part is not used right now for anything yet because it is often hard to know how many items of work there are. For symbol tables in ELF, we have two of them, but we might also create new symbols from EH frame or other sources when there are no symbols, so it was hard to pre-determine a full number of symbols for a given executable. Same goes for mach-o files with the normal symbol table, then new symbols are created from the LC_FUNCTION_STARTS load command that has start addresses for all functions, many of which have symbols. For DWARF, we have 3 ways to index the DWARF: Apple tables, .debug_names, and manually. I will comment inline where we could specify a valid number of work items for DWARF to improve the feedback. The other reason the progress objects don't report immediate feedback is the frequency of the progress callbacks could slow things down if they are called too often with too little work. I am happy to talk about any of these issues if anyone has any questions.

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Comment at: lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp:470-472
+  Progress progress(
+      UINT64_MAX, "Indexing DWARF for %s",
+      GetObjectFile()->GetFileSpec().GetFilename().AsCString("<Unknown>"));
----------------
Instead of specifying UINT64_MAX as the number of work items here, we can figure out how many compile units exist in the DWARF and use that number, and then a reference to this progress object can be passed into the various indexing calls below and can be updated as the DWARF is parsed.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D97739/new/

https://reviews.llvm.org/D97739