[PATCH] D59553: [LLD][ELF][DebugInfo] llvm-symbolizer shows incorrect source line info if --gc-sections used

[Alexey Lapshin via Phabricator via llvm-commits]

avl added a comment.

> Does this do the right thing for a 32-bit target? 64-bit is common, but not universal.

yes, it does.

$ clang++ -gdwarf-5 -O main.cpp -c -m32
$ clang++ -gdwarf-5 -O not_used.cpp -c -m32
$ clang++ -gdwarf-5 -O not_used.o main.o -Wl,--gc-sections -o res.out -m32 -fuse-ld=lld 
$ llvm-symbolizer -obj=res.out 0x401110
main
/home/avl/bugs/gc_debuginfo/main.cpp:2:4

$ llvm-symbolizer -obj=res.out 0xfffffffe
_fini
/home/avl/bugs/gc_debuginfo/not_used.cpp:2:5

  DW_TAG_compile_unit
  DW_AT_producer    ("clang version 9.0.0")
  DW_AT_language    (DW_LANG_C_plus_plus)
  DW_AT_name        ("main.cpp")
  DW_AT_str_offsets_base    (0x00000024)
  DW_AT_stmt_list   (0x00000071)
  DW_AT_comp_dir    ("/home/avl/bugs/gc_debuginfo")
  DW_AT_addr_base   (0x00000014)
  DW_AT_low_pc      (0x0000000000401110)
  DW_AT_high_pc     (0x0000000000401113)
  
  DW_TAG_compile_unit
  DW_AT_producer    ("clang version 9.0.0")
  DW_AT_language    (DW_LANG_C_plus_plus)
  DW_AT_name        ("not_used.cpp")
  DW_AT_str_offsets_base    (0x00000008)
  DW_AT_stmt_list   (0x00000000)
  DW_AT_comp_dir    ("/home/avl/bugs/gc_debuginfo")
  DW_AT_addr_base   (0x00000008)
  DW_AT_low_pc      (0x00000000fffffffe)
  DW_AT_high_pc     (0x0000000100325a9f)

I would add 32-bit test case .


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  https://reviews.llvm.org/D59553/new/

https://reviews.llvm.org/D59553