rZhBoYao added a comment.
Hi all, I found this patch causing PR52702 <https://llvm.org/PR52702> in that
the parent of this commit
<https://github.com/llvm/llvm-project/commit/ec1a4917> and LLDB 12 worked fine.
When disassembling a hello world C program on Linux, LLDB used to show
`callq 0x401030 ; symbol stub for: puts`
instead of
`callq 0x401030 ; symbol stub for: ___lldb_unnamed_symbol36`.
Examining the symbol table by running `lldb -b -o 'image dump symtab' a.out`
used to show:
[ 18] 20 X Undefined 0x0000000000000000
0x0000000000000000 0x00000012 puts@GLIBC_2.2.5
........
[ 33] 35 X Code 0x0000000000401000
0x000000000000001b 0x00000212 _init
[ 34] 36 S Trampoline 0x0000000000401030
0x0000000000000010 0x00000000 puts
[ 35] 37 SX Code 0x0000000000401020
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol1$$a.out
and now (ToT and LLDB 13) it's:
[ 18] 20 X Undefined 0x0000000000000000
0x0000000000000000 0x00000012 puts@GLIBC_2.2.5
........
[ 33] 35 X Code 0x0000000000401000
0x000000000000001b 0x00000212 _init
[ 34] 36 S Trampoline 0x0000000000401030
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol36
[ 35] 37 SX Code 0x0000000000401020
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol37
`image dump symtab libc.so.6` gives similar result.
Before ec1a4917 <https://github.com/llvm/llvm-project/commit/ec1a4917> :
[ 2366] 2367 S Trampoline 0x0000000000025010 0x00007ffff7df2010
0x0000000000000010 0x00000000 realloc
[ 2367] 2368 S Trampoline 0x0000000000025020 0x00007ffff7df2020
0x0000000000000010 0x00000000 __tls_get_addr
[ 2368] 2369 S Trampoline 0x0000000000025030 0x00007ffff7df2030
0x0000000000000010 0x00000000 memalign
[ 2369] 2370 S Trampoline 0x0000000000025040 0x00007ffff7df2040
0x0000000000000010 0x00000000 _dl_exception_create
[ 2370] 2371 S Trampoline 0x0000000000025050 0x00007ffff7df2050
0x0000000000000010 0x00000000 __tunable_get_val
[ 2371] 2372 S Trampoline 0x0000000000025060 0x00007ffff7df2060
0x0000000000000010 0x00000000 _dl_find_dso_for_object
[ 2372] 2373 S Trampoline 0x0000000000025070 0x00007ffff7df2070
0x0000000000000010 0x00000000 calloc
[ 2373] 2373 SX Code 0x0000000000025000 0x00007ffff7df2000
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol1$$libc.so.6
[ 2374] 2373 SX Code 0x0000000000025300 0x00007ffff7df2300
0x0000000000000040 0x00000000 ___lldb_unnamed_symbol2$$libc.so.6
[ 2375] 2373 SX Code 0x0000000000025340 0x00007ffff7df2340
0x00000000000002f0 0x00000000 ___lldb_unnamed_symbol3$$libc.so.6
[ 2376] 2373 SX Code 0x0000000000025630 0x00007ffff7df2630
0x000000000000000c 0x00000000 ___lldb_unnamed_symbol4$$libc.so.6
After:
[ 2366] 2367 S Trampoline 0x0000000000025010 0x00007ffff7df2010
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2367
[ 2367] 2368 S Trampoline 0x0000000000025020 0x00007ffff7df2020
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2368
[ 2368] 2369 S Trampoline 0x0000000000025030 0x00007ffff7df2030
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2369
[ 2369] 2370 S Trampoline 0x0000000000025040 0x00007ffff7df2040
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2370
[ 2370] 2371 S Trampoline 0x0000000000025050 0x00007ffff7df2050
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2371
[ 2371] 2372 S Trampoline 0x0000000000025060 0x00007ffff7df2060
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2372
[ 2372] 2373 S Trampoline 0x0000000000025070 0x00007ffff7df2070
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2373
[ 2373] 2374 SX Code 0x0000000000025000 0x00007ffff7df2000
0x0000000000000010 0x00000000 ___lldb_unnamed_symbol2374
[ 2374] 2375 SX Code 0x0000000000025300 0x00007ffff7df2300
0x0000000000000040 0x00000000 ___lldb_unnamed_symbol2375
[ 2375] 2376 SX Code 0x0000000000025340 0x00007ffff7df2340
0x00000000000002f0 0x00000000 ___lldb_unnamed_symbol2376
[ 2376] 2377 SX Code 0x0000000000025630 0x00007ffff7df2630
0x000000000000000c 0x00000000 ___lldb_unnamed_symbol2377
Is this intended for the performance boost? It seems to me that "`S
Trampoline`" symbols should be handled differently.
FWIW, I also found that this doesn't affect macOS tho as `puts` is not even a
synthetic symbol:
Index UserID DSX Type File Address/Value Load Address Size
Flags Name
------- ------ --- --------------- ------------------ ------------------
------------------ ---------- ----------------------------------
[ 0] 0 Data 0x0000000100008008
0x0000000000000008 0x000e0000 _dyld_private
[ 1] 1 X Data 0x0000000100000000
0x0000000000003f70 0x000f0010 _mh_execute_header
[ 2] 2 X Code 0x0000000100003f70
0x0000000000000014 0x000f0000 main
[ 3] 3 Trampoline 0x0000000100003f84
0x0000000000000006 0x00010100 puts
[ 4] 4 X Undefined 0x0000000000000000
0x0000000000000000 0x00010100 dyld_stub_binder
callq 0x100003f84 ; symbol stub for: puts
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D106837/new/
https://reviews.llvm.org/D106837
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