[PATCH] D144999: [Clang][MC][MachO]Only emits compact-unwind format for "canonical" personality symbols. For the rest, use DWARFs.

[Vy Nguyen via Phabricator via cfe-commits]

oontvoo added a comment.

In D144999#4415419 <https://reviews.llvm.org/D144999#4415419>, @oontvoo wrote:

> In D144999#4415137 <https://reviews.llvm.org/D144999#4415137>, @jasonmolenda wrote:
>
>> Michael and I looked into this.  This simple c++ file is resulting in eh_frame unwind info on aarch64 darwin instead of compact unwind info.

P.S: still no luck reproducing this with TOT clang.  Would you mind verifying my test case below (this was on M1 <https://reviews.llvm.org/M1> mac):

  ### clang is built with commit up to 5b1c62c0f2e9a739707429f650cb897c067f86c2
  vyng-macbookpro3 /Users/vyng/repo/llvm-project/build_all$ ./bin/clang++  ../cross-project-tests/debuginfo-tests/dexter-tests/optnone-struct-and-methods.cpp -g -O0 -c -o test_tot.o
  
  vyng-macbookpro3 /Users/vyng/repo/llvm-project/build_all$ objdump --macho --unwind-info --dwarf=frames  test_tot.o
  Contents of __compact_unwind section:
    Entry at offset 0x0:
      start:                0x0 ltmp0
      length:               0x70
      compact encoding:     0x44000000
      personality function: 0x0 ___gxx_personality_v0
      LSDA:                 0x238 ltmp1
    Entry at offset 0x20:
      start:                0x70 __ZN12_GLOBAL__N_11AC1Ev
      length:               0x2c
      compact encoding:     0x04000000
    Entry at offset 0x40:
      start:                0x9c __ZN12_GLOBAL__N_11A7getDataEv
      length:               0x78
      compact encoding:     0x04000000
    Entry at offset 0x60:
      start:                0x114 __ZN12_GLOBAL__N_11AD1Ev
      length:               0x2c
      compact encoding:     0x04000000
    Entry at offset 0x80:
      start:                0x140 __ZN12_GLOBAL__N_11AC2Ev
      length:               0x2c
      compact encoding:     0x02001000
    Entry at offset 0xa0:
      start:                0x16c __ZN12_GLOBAL__N_11A12setOtherDataEv
      length:               0x74
      compact encoding:     0x04000000
    Entry at offset 0xc0:
      start:                0x1e0 __ZN12_GLOBAL__N_11A12getOtherDataEv
      length:               0x18
      compact encoding:     0x02001000
    Entry at offset 0xe0:
      start:                0x1f8 __ZN12_GLOBAL__N_11AD2Ev
      length:               0x40
      compact encoding:     0x04000000
  
  .debug_frame contents:
  
  
  .eh_frame contents:
  <<<< nothing in eh_frame section, which is expected and matches what produced by base clang




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https://reviews.llvm.org/D144999