Ruby1.9的隐藏参数"--dump"
前几天，我的同事老高在看Ruby1.9.2源码的时候，发现Ruby1.9有一个隐藏参数:"--dump"(注意是两个减号). 下面具体说说这个参数:
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1. --dump 参数
--dump 可以打印出ruby及指定脚本的相关信息，具体如下：
[version, copyright, usage, yydebug, syntax, parsetree, parsetree_with_comment, insns]
其中有几项的内容我们已经熟悉，例如:version,copyright,usage. 不过这次我们感兴趣的是parsetree和insns的内容。
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parsetree -- 打印指定脚本的Parse Tree
insns??????? -- 打印指定脚本的RubyVM(YARV)指令
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2. 具体用法举例
假设有一个已经写好的脚本1.rb,存放在C盘。我们可以如下使用"--dump"参数:
ruby --dump parsetree c:\1.rb
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3.测试结果
测试脚本:
class A def hello puts 'Hello' endendA.new.hello
打印RubyVM指令：ruby --dump insns c:\1.rb
输出
== disasm: <RubyVM::InstructionSequence:<main>@c:/1.rb>=================0000 trace 1 ( 1)0002 putspecialobject 30004 putnil0005 defineclass :A, <class:A>, 00009 pop0010 trace 1 ( 7)0012 getinlinecache 19, <ic:0>0015 getconstant :A0017 setinlinecache <ic:0>0019 send :new, 0, nil, 0, <ic:1>0025 send :hello, 0, nil, 0, <ic:2>0031 leave== disasm: <RubyVM::InstructionSequence:<class:A>@c:/1.rb>==============0000 trace 2 ( 1)0002 trace 1 ( 2)0004 putspecialobject 10006 putspecialobject 20008 putobject :hello0010 putiseq hello0012 send :"core#define_method", 3, nil, 0, <ic:0>0018 trace 4 ( 5)0020 leave ( 2)== disasm: <RubyVM::InstructionSequence:hello@c:/1.rb>==================0000 trace 8 ( 2)0002 trace 1 ( 3)0004 putnil0005 putstring "Hello"0007 send :puts, 1, nil, 8, <ic:0>0013 trace 16 ( 4)0015 leave ( 3)?
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打印ParseTree：ruby --dump parsetree c:\1.rb
输出:
############################################################# Do NOT use this node dump for any purpose other than #### debug and research. Compatibility is not guaranteed. ############################################################## @ NODE_SCOPE (line: 7)# +- nd_tbl: (empty)# +- nd_args:# | (null node)# +- nd_body:# @ NODE_BLOCK (line: 1)# +- nd_head:# | @ NODE_CLASS (line: 1)# | +- nd_cpath:# | | @ NODE_COLON2 (line: 1)# | | +- nd_mid: :A# | | +- nd_head:# | | (null node)# | +- nd_super:# | | (null node)# | +- nd_body:# | @ NODE_SCOPE (line: 5)# | +- nd_tbl: (empty)# | +- nd_args:# | | (null node)# | +- nd_body:# | @ NODE_DEFN (line: 2)# | +- nd_mid: :hello# | +- nd_defn:# | @ NODE_SCOPE (line: 4)# | +- nd_tbl: (empty)# | +- nd_args:# | | @ NODE_ARGS (line: 2)# | | +- nd_frml: 0# | | +- nd_next:# | | | @ NODE_ARGS_AUX (line: 2)# | | | +- nd_rest: (null)# | | | +- nd_body: (null)# | | | +- nd_next:# | | | (null node)# | | +- nd_opt:# | | (null node)# | +- nd_body:# | @ NODE_FCALL (line: 3)# | +- nd_mid: :puts# | +- nd_args:# | @ NODE_ARRAY (line: 3)# | +- nd_alen: 1# | +- nd_head:# | | @ NODE_STR (line: 3)# | | +- nd_lit: "Hello"# | +- nd_next:# | (null node)# +- nd_next:# @ NODE_BLOCK (line: 7)# +- nd_head:# | @ NODE_CALL (line: 7)# | +- nd_mid: :hello# | +- nd_recv:# | | @ NODE_CALL (line: 7)# | | +- nd_mid: :new# | | +- nd_recv:# | | | @ NODE_CONST (line: 7)# | | | +- nd_vid: :A# | | +- nd_args:# | | (null node)# | +- nd_args:# | (null node)# +- nd_next:# (null node)?
