[all-commits] [llvm/llvm-project] 0ff28f: Support dwarf fission for wasm object files

[Derek Schuff via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 0ff28fa6a75617d61b1aeea77463d6a1684c3c89
      https://github.com/llvm/llvm-project/commit/0ff28fa6a75617d61b1aeea77463d6a1684c3c89
  Author: Derek Schuff <dschuff at chromium.org>
  Date:   2020-09-17 (Thu, 17 Sep 2020)

  Changed paths:
    M clang/lib/Driver/ToolChains/Clang.cpp
    M clang/test/Driver/split-debug.c
    M llvm/include/llvm/MC/MCWasmObjectWriter.h
    M llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
    M llvm/lib/MC/MCAsmBackend.cpp
    M llvm/lib/MC/MCObjectFileInfo.cpp
    M llvm/lib/MC/WasmObjectWriter.cpp
    A llvm/test/DebugInfo/WebAssembly/fission-cu.ll
    A llvm/test/DebugInfo/WebAssembly/fission-sections.ll

  Log Message:
  -----------
  Support dwarf fission for wasm object files

Initial support for dwarf fission sections (-gsplit-dwarf) on wasm.
The most interesting change is support for writing 2 files (.o and .dwo) in the
wasm object writer. My approach moves object-writing logic into its own function
and calls it twice, swapping out the endian::Writer (W) in between calls.
It also splits the import-preparation step into its own function (and skips it when writing a dwo).

Differential Revision: https://reviews.llvm.org/D85685