56 lines
1.5 KiB
Ruby
56 lines
1.5 KiB
Ruby
#
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# Listing C's global variables in .so or .o, or .bundle on Mac OS using "objdump -t" (elf64-x86-64)
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# to check ractor-safety.
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#
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# Usage: ruby search-cgvars.rb foo.so bar.o .ext/x86_64-darwin18/psych.bundle
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#
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MAC_OS = RbConfig::CONFIG['host_os'].match? /darwin|mac os/
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def gvars file
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# '0000000000031ac8 g O .bss 0000000000000008 rb_cSockIfaddr'
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# On mac, with .bundle files:
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# '0000000000004258 l O __DATA,__bss _passwd_blocking'
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strs = `objdump -t #{file}`
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found = {}
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strs.each_line{|line|
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if /[\da-f]{16} / =~ line
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addr = line[0...16]
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flags = line[17...24].tr(' ', '').split(//).sort.uniq
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rest = line[25..]
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if MAC_OS
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seg, name = rest.split(/\s+/)
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else
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seg, size, name = rest.split(/\s+/)
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end
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if flags.include?('O')
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# p [addr, flags, seg, size, name]
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found[name] = [flags, seg, *size]
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end
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end
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}
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puts "## #{file}:"
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found.sort_by{|name, (flags, *)|
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[flags, name]
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}.each{|name, rest|
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flags, seg, size = *rest
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next if (size.to_i == 0 && !MAC_OS) && seg != '*UND*'
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case seg
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when ".rodata", ".data.rel.ro", ".got.plt", ".eh_frame", ".fini_array"
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next
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when /,__const$/ # Mac OS
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next
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end
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case name
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when /^id_/, /^rbimpl_id/, /^sym_/, /^rb_[cme]/, /\Acompleted\.\d+\z/
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next
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when /^_id_/, /\.rbimpl_id(\.\d+)?$/ # Mac OS
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next
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end
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puts " %40s %s" % [name, rest.inspect]
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}
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end
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ARGV.each{|file|
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gvars file
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}
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