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:
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。
parsetree -- 打印指定脚本的Parse Tree
insns -- 打印指定脚本的RubyVM(YARV)指令
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
3.测试结果
测试脚本:
class A
def hello
puts 'Hello'
end
end
A.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 3 0004 putnil 0005 defineclass :A, <class:A>, 0 0009 pop 0010 trace 1 ( 7) 0012 getinlinecache 19, <ic:0> 0015 getconstant :A 0017 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 1 0006 putspecialobject 2 0008 putobject :hello 0010 putiseq hello 0012 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 putnil 0005 putstring "Hello" 0007 send :puts, 1, nil, 8, <ic:0> 0013 trace 16 ( 4) 0015 leave ( 3)
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)