123 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Ruby
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Ruby
		
	
	
	
	
	
| # typed: true # rubocop:todo Sorbet/StrictSigil
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| # frozen_string_literal: true
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| 
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| require "fcntl"
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| require "socket"
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| 
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| module Utils
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|   def self.rewrite_child_error(child_error)
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|     inner_class = Object.const_get(child_error["json_class"])
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|     error = if child_error["cmd"] && inner_class == ErrorDuringExecution
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|       ErrorDuringExecution.new(child_error["cmd"],
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|                                status: child_error["status"],
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|                                output: child_error["output"])
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|     elsif child_error["cmd"] && inner_class == BuildError
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|       # We fill `BuildError#formula` and `BuildError#options` in later,
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|       # when we rescue this in `FormulaInstaller#build`.
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|       BuildError.new(nil, child_error["cmd"], child_error["args"], child_error["env"])
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|     elsif inner_class == Interrupt
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|       Interrupt.new
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|     else
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|       # Everything other error in the child just becomes a RuntimeError.
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|       RuntimeError.new <<~EOS
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|         An exception occurred within a child process:
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|           #{inner_class}: #{child_error["m"]}
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|       EOS
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|     end
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| 
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|     error.set_backtrace child_error["b"]
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| 
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|     error
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|   end
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| 
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|   # When using this function, remember to call `exec` as soon as reasonably possible.
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|   # This function does not protect against the pitfalls of what you can do pre-exec in a fork.
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|   # See `man fork` for more information.
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|   def self.safe_fork(directory: nil, yield_parent: false)
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|     require "json/add/exception"
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| 
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|     block = proc do |tmpdir|
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|       UNIXServer.open("#{tmpdir}/socket") do |server|
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|         read, write = IO.pipe
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| 
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|         pid = fork do
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|           # bootsnap doesn't like these forked processes
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|           ENV["HOMEBREW_NO_BOOTSNAP"] = "1"
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|           error_pipe = server.path
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|           ENV["HOMEBREW_ERROR_PIPE"] = error_pipe
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|           server.close
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|           read.close
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|           write.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
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| 
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|           Process::UID.change_privilege(Process.euid) if Process.euid != Process.uid
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| 
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|           yield(error_pipe)
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|         rescue Exception => e # rubocop:disable Lint/RescueException
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|           error_hash = JSON.parse e.to_json
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| 
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|           # Special case: We need to recreate ErrorDuringExecutions
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|           # for proper error messages and because other code expects
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|           # to rescue them further down.
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|           if e.is_a?(ErrorDuringExecution)
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|             error_hash["cmd"] = e.cmd
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|             error_hash["status"] = if e.status.is_a?(Process::Status)
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|               {
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|                 exitstatus: e.status.exitstatus,
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|                 termsig:    e.status.termsig,
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|               }
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|             else
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|               e.status
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|             end
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|             error_hash["output"] = e.output
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|           end
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| 
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|           write.puts error_hash.to_json
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|           write.close
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| 
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|           exit!
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|         else
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|           exit!(true)
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|         end
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| 
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|         pid = T.must(pid)
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| 
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|         begin
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|           yield(nil) if yield_parent
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| 
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|           begin
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|             socket = server.accept_nonblock
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|           rescue Errno::EAGAIN, Errno::EWOULDBLOCK, Errno::ECONNABORTED, Errno::EPROTO, Errno::EINTR
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|             retry unless Process.waitpid(pid, Process::WNOHANG)
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|           else
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|             socket.send_io(write)
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|             socket.close
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|           end
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|           write.close
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|           data = read.read
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|           read.close
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|           Process.waitpid(pid) unless socket.nil?
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|         rescue Interrupt
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|           Process.waitpid(pid)
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|         end
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| 
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|         # 130 is the exit status for a process interrupted via Ctrl-C.
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|         raise Interrupt if $CHILD_STATUS.exitstatus == 130
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|         raise Interrupt if $CHILD_STATUS.termsig == Signal.list["INT"]
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| 
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|         if data.present?
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|           error_hash = JSON.parse(T.must(data.lines.first))
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|           raise rewrite_child_error(error_hash)
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|         end
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| 
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|         raise ChildProcessError, $CHILD_STATUS unless $CHILD_STATUS.success?
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|       end
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|     end
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| 
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|     if directory
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|       block.call(directory)
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|     else
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|       Dir.mktmpdir("homebrew-fork", HOMEBREW_TEMP, &block)
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|     end
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|   end
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| end
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