Erlang 代码束文件在哪里?
我已经打印了所有加载的代码如下,为什么 {lager_default_tracer,[]},beam文件在哪里Erlang 代码束文件在哪里?,erlang,lager,Erlang,Lager,我已经打印了所有加载的代码如下,为什么 {lager_default_tracer,[]},beam文件在哪里 (lager_test_1@macbook.local)10> io:format("~p",[code:all_loaded()]). [{io,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/io.beam"}, {erl_distribution,"/usr/local/lib/erlang/lib/kernel-3.1/ebin/e
(lager_test_1@macbook.local)10> io:format("~p",[code:all_loaded()]).
[{io,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/io.beam"},
{erl_distribution,"/usr/local/lib/erlang/lib/kernel-3.1/ebin/erl_distribution.beam"},
{edlin,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/edlin.beam"},
{beam_clean,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/beam_clean.beam"},
{v3_core,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/v3_core.beam"},
{erl_epmd,"/usr/local/lib/erlang/lib/kernel-3.1/ebin/erl_epmd.beam"},
{love_misc,"/usr/local/bin/lager_test/lib/hanoch-0.0.1.6/ebin/love_misc.beam"},
{zlib,preloaded},
{error_handler,"/usr/local/lib/erlang/lib/kernel-3.1/ebin/error_handler.beam"},
{io_lib,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/io_lib.beam"},
{lib,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/lib.beam"},
{mnesia,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia.beam"},
{lager_test_app,"/usr/local/bin/lager_test/lib/lager_test-0.0.1.0/ebin/lager_test_app.beam"},
{beam_jump,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/beam_jump.beam"},
{v3_codegen,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/v3_codegen.beam"},
{beam_flatten,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/beam_flatten.beam"},
{mnesia_tm,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_tm.beam"},
{prim_eval,preloaded},
{beam_bool,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/beam_bool.beam"},
{error_logger_lager_h,"/usr/local/bin/lager_test/lib/lager-2.0.0/ebin/error_logger_lager_h.beam"},
{lager_msg,"/usr/local/bin/lager_test/lib/lager-2.0.0/ebin/lager_msg.beam"},
{mnesia_frag,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_frag.beam"},
{filename,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/filename.beam"},
{lager_default_tracer,[]},
{lager_default_formatter,"/usr/local/bin/lager_test/lib/lager-2.0.0/ebin/lager_default_formatter.beam"},
{mnesia_locker,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_locker.beam"},
{mnesia_recover,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_recover.beam"},
{mnesia_dumper,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_dumper.beam"},
{mnesia_kernel_sup,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_kernel_sup.beam"},
{mnesia_sp,"/usr/local/lib/erlang/lib/mnesia-4.12.4/ebin/mnesia_sp.beam"},
{erts_internal,preloaded},
{unicode,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/unicode.beam"},
{lager_backend_throttle,"/usr/local/bin/lager_test/lib/lager-2.0.0/ebin/lager_backend_throttle.beam"},
{beam_type,"/usr/local/lib/erlang/lib/compiler-5.0.3/ebin/beam_type.beam"},
{orddict,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/orddict.beam"},
{gb_sets,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/gb_sets.beam"},
{sofs,"/usr/local/lib/erlang/lib/stdlib-2.3/ebin/sofs.beam"},
{inet_db,"/usr/local/lib/erlang/lib/kernel-3.1/ebin/inet_db.beam"},
{lager_test_a,"/usr/local/bin/lager_test/lib/lager_test-0.0.1.0/ebin/lager_test_a.beam"},
{inet,"/usr/local/lib/erlang/lib/kernel-3.1/ebin/inet.beam"},
调用module_info()时,如下所示:
(lager_test_1@macbook.local)11> lager_default_tracer:module_info().
[{exports,[{table,1},
{handle,1},
{module_info,0},
{module_info,1},
{info,1}]},
{imports,[]},
{attributes,[{vsn,[203040246025344403396962742072895880482]}]},
{compile,[{options,[]},
{version,"5.0.3"},
{time,{2017,8,27,5,43,32}},
{source,"/private/tmp/lager_test-0.0.1.0"}]}]
(lager_test_1@macbook.local)12> lager_default_tracer:table(aaa).
** exception error: bad argument
in function lager_default_tracer:table/1
当我调用lager\u default\u tracer:table(111)
时,它如下所示:
(lager_test_1@macbook.local)11> lager_default_tracer:module_info().
[{exports,[{table,1},
{handle,1},
{module_info,0},
{module_info,1},
{info,1}]},
{imports,[]},
{attributes,[{vsn,[203040246025344403396962742072895880482]}]},
{compile,[{options,[]},
{version,"5.0.3"},
{time,{2017,8,27,5,43,32}},
{source,"/private/tmp/lager_test-0.0.1.0"}]}]
(lager_test_1@macbook.local)12> lager_default_tracer:table(aaa).
** exception error: bad argument
in function lager_default_tracer:table/1
lager\u default\u tracer
模块没有关联的beam文件,因为它是在运行时创建的。lager
应用程序使用,它使用运行时代码编译和加载
如果您仔细查看,您会发现它调用了动态编译的标准。通过跟踪该调用,我们可以使用以下步骤重构lager\u default\u tracer
的源代码,这些步骤假定您已经克隆并成功编译了。在某些步骤中,erlangshell命令的输出太大,无法放在这里,因此这些部分使用省略号缩写
lager
repo目录中,运行rebar shell
启动Erlang shell,以确保所有必要的目录都位于Erlang加载路径中compile:forms/2
:
1> dbg:tracer(), dbg:p(all, call).
{ok,[{matched,nonode@nohost,34}]}
2> dbg:tpl(compile, forms, []).
{ok,[{matched,nonode@nohost,2}]}
lager
应用程序及其依赖项:
3> application:ensure_all_started(lager).
这将导致dbg
跟踪产生如下冗长的输出:
()调用compile:forms([{attribute,0,module,lager\u default\u tracer},
...
{tuple,0,[{integer,0,2},{integer,0,1}]}]}]}],[nowarn\u unused\u vars])
{好的,[语法工具,编译器,goldrush,lager]}
08:29:21.478[信息]节点上的应用程序已启动nonode@nohost
这里,输出缩写为仅显示第一行和最后几行。最后两行是应用程序的结果:确保\u所有\u已启动/1
。这些行上方的所有内容都是lager\u default\u tracer
模块的内容[{attribute,0,module,lager\u default\u tracer}
一直复制到输出跟踪最后一行的{tuple,0,[{integer,0,2},{integer,0,1}]}]
。不要在复制内容中包含结尾文本[nowarn\u unused\u vars])
M
的变量:
4>M=[{attribute,0,module,lager\u default\u tracer},
...
{tuple,0,[{integer,0,2},{integer,0,1}]}]}]。
不要忘记添加最后一个句点(也称为句号)来完成表达式dbg
跟踪:
5>dbg:stop_clear()。
好啊
6>{ok,u,B}=compile:forms(M,[no_unused_vars,debug_info])。
{好的,大杯啤酒,
}
变量B
现在以二进制形式保存lager\u default\u tracer
模块的编译代码B
中的已编译二进制文件中提取抽象代码块:
7>{ok,{{{uu,[{abstract\u code,{uu,AC}]}}=beam\u lib:chunks(B,[abstract\u code])。
{好的,{lager\u default\u tracer,
[{抽象代码,
...
[{子句,0,[{var,0,'Event'}],[{call,…}]}]}]}}
变量AC
现在保存抽象代码lager\u default\u tracer
模块的重构源代码:
8>io:fwrite(“~s~n”,[erl\u prettypr:format(erl\u语法:form\u list(AC)))。
-模块(较大的默认跟踪程序)。
-导出([info/1,重置计数器/1,表/1,句柄/1])。
...
句柄(事件)->
gr_计数器:更新_计数器(表(计数器)、过滤器、,
{2, 1}).
好啊
这最后一步和它之前的一步是从“重构源代码”下的毫不奇怪,重构的源代码显示了对其他
goldrush
函数的调用,因此如果您想尝试理解重构的代码,您需要访问。较大的默认跟踪程序模块没有相关联的beam文件,因为它是在运行时创建的。lager
应用程序使用,它使用运行时代码编译和加载
如果您仔细查看,您会发现它调用了动态编译的标准。通过跟踪该调用,我们可以使用以下步骤重构lager\u default\u tracer
的源代码,这些步骤假定您已经克隆并成功编译了。在某些步骤中,erlangshell命令的输出太大,无法放在这里,因此这些部分使用省略号缩写
lager
repo目录中,运行rebar shell
启动Erlang shell,以确保所有必要的目录都位于Erlang加载路径中compile:forms/2
:
1> dbg:tracer(), dbg:p(all, call).
{ok,[{matched,nonode@nohost,34}]}
2> dbg:tpl(compile, forms, []).
{ok,[{matched,nonode@nohost,2}]}
lager
应用程序及其依赖项:
3> application:ensure_all_started(lager).
这将导致dbg
跟踪产生如下冗长的输出:
()调用compile:forms([{attribute,0,module,lager\u default\u tracer},
...
{tuple,0,[{integer,0,2},{integer,0,1}]}]}]}],[nowarn\u unused\u vars])
{好的,[语法工具,编译器,goldrush,lager]}
08:29:21.478[信息]节点上的应用程序已启动nonode@nohost
这里,输出缩写为仅显示第一行和最后几行。最后两行是应用程序的结果:确保\u所有\u已启动/1
。这些行上方的所有内容都是lager\u default\u tracer
模块的内容[{attribute,0,module,lager\u default\u tracer}
一直复制到输出跟踪最后一行的{tuple,0,[{integer,0,2},{integer,0,1}]}]
。不要在您复制的内容中包含结尾文本[nowarn\u unused\u vars])
。