ec1a491701
This is a resubmission of https://reviews.llvm.org/D105160 after fixing testing issues. This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool. Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index. This patch fixes the issue by: not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool Prior to this fix the startup times for a large application was: 12.5 seconds (cold file caches) 8.5 seconds (warm file caches) After this fix: 9.7 seconds (cold file caches) 5.7 seconds (warm file caches) The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name. Differential Revision: https://reviews.llvm.org/D106837
26 lines
1.5 KiB
Plaintext
26 lines
1.5 KiB
Plaintext
# RUN: yaml2obj %S/Inputs/basic-elf.yaml -o %T/symtab.out
|
|
# RUN: %lldb %T/symtab.out -o "target symbols add -s symtab.out %S/Inputs/symtab.syms" \
|
|
# RUN: -s %s | FileCheck %s
|
|
|
|
# CHECK-LABEL: (lldb) image dump symtab symtab.out
|
|
# CHECK: Symtab, file = {{.*}}symtab.out, num_symbols = 5:
|
|
# CHECK: Index UserID DSX Type File Address/Value Load Address Size Flags Name
|
|
# CHECK: [ 0] 0 SX Code 0x0000000000400000 0x00000000000000b0 0x00000000 ___lldb_unnamed_symbol{{[0-9]*}}
|
|
# CHECK: [ 1] 0 X Code 0x00000000004000b0 0x000000000000000c 0x00000000 f1_func
|
|
# CHECK: [ 2] 0 X Code 0x00000000004000a0 0x000000000000000d 0x00000000 func_only
|
|
# CHECK: [ 3] 0 X Code 0x00000000004000c0 0x0000000000000010 0x00000000 f2
|
|
# CHECK: [ 4] 0 X Code 0x00000000004000d0 0x0000000000000022 0x00000000 _start
|
|
|
|
# CHECK-LABEL: (lldb) image lookup -a 0x4000b0 -v
|
|
# CHECK: Address: symtab.out[0x00000000004000b0] (symtab.out.PT_LOAD[0]..text2 + 0)
|
|
# CHECK: Symbol: id = {0x00000000}, range = [0x00000000004000b0-0x00000000004000bc), name="f1_func"
|
|
|
|
# CHECK-LABEL: (lldb) image lookup -n f2 -v
|
|
# CHECK: Address: symtab.out[0x00000000004000c0] (symtab.out.PT_LOAD[0]..text2 + 16)
|
|
# CHECK: Symbol: id = {0x00000000}, range = [0x00000000004000c0-0x00000000004000d0), name="f2"
|
|
|
|
image dump symtab symtab.out
|
|
image lookup -a 0x4000b0 -v
|
|
image lookup -n f2 -v
|
|
exit
|