[PATCH] D61672: [llvm-objcopy] Allow strip symtab in executables and DSOs

[Eugene Leviant via Phabricator via llvm-commits]

evgeny777 added a comment.

> I'm still a bit unclear. Does it strip symbols that are duplicates of symbols in .dynsym? Does it just get rid of the the whole symbol table no matter what?

For ET_DYN/EXEC GNU objcopy strips all symbols from .symtab when they're not referenced by relocations. Given DYN/EXEC is a product of a static linker there're no such
symbols, so effectively all symbols from .symtab are stripped. As a result symtab section becomes empty and is not emitted to output binary.

> I think --strip-unneeded already strips debug sections as well



  llvm-objcopy --help
  ...
  -strip-unneeded         Remove all symbols not needed by relocations
  ...



> Also what "strip unneeded" means is a bit unclear.

I think it's pretty clear. You remove symbols not referenced by relocations compacting both .symtab and .strtab

> There unfortunately isn't a spec anywhere nor is the use case implied by "needed" defined. We just have to match GNU objcopy.

I couldn't find any docs on the subject, so I can only suggest taking a look at GNU objcopy `filter_symbols`.


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https://reviews.llvm.org/D61672