[all-commits] [llvm/llvm-project] 69b312: [llvm-objdump] Create fake sections for a ELF core...

[Namhyung Kim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 69b312cde428056186928a3c1b6ad84e45de0353
      https://github.com/llvm/llvm-project/commit/69b312cde428056186928a3c1b6ad84e45de0353
  Author: Namhyung Kim <namhyung at google.com>
  Date:   2022-07-14 (Thu, 14 Jul 2022)

  Changed paths:
    M llvm/include/llvm/Object/ELF.h
    M llvm/include/llvm/Object/ELFObjectFile.h
    M llvm/test/Object/objdump-no-sectionheaders.test
    A llvm/test/tools/llvm-objdump/X86/disassemble-no-section.test
    M llvm/tools/llvm-objdump/llvm-objdump.cpp
    M llvm/tools/llvm-objdump/llvm-objdump.h

  Log Message:
  -----------
  [llvm-objdump] Create fake sections for a ELF core file

The linux perf tools use /proc/kcore for disassembly kernel functions.
Actually it copies the relevant parts to a temp file and then pass it to
objdump. But it doesn't have section headers so llvm-objdump cannot
handle it.

Let's create fake section headers for the program headers. It'd have a
single section for each segment to cover the entire range. And for this
purpose we can consider only executable code segments.

With this change, I can see the following command shows proper outputs.

perf annotate --stdio --objdump=/path/to/llvm-objdump

Differential Revision: https://reviews.llvm.org/D128705