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authorErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
committerErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
commit84adefa331c4159d432d22840663c38f155cd4c1 (patch)
treebff9a9c66adda4df2106dfd0e5c053ab182a12bd /lib/kernel/src/erts_debug.erl
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The R13B03 release.OTP_R13B03
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+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(erts_debug).
+
+%% Low-level debugging support. EXPERIMENTAL!
+
+-export([size/1,df/1,df/2,df/3]).
+
+%% This module contains the following *experimental* BIFs:
+%% disassemble/1
+%% breakpoint/2
+%% same/2
+%% flat_size/1
+
+%% size(Term)
+%% Returns the size of Term in actual heap words. Shared subterms are
+%% counted once. Example: If A = [a,b], B =[A,A] then size(B) returns 8,
+%% while flat_size(B) returns 12.
+
+-spec size(term()) -> non_neg_integer().
+
+size(Term) ->
+ {Sum,_} = size(Term, gb_trees:empty(), 0),
+ Sum.
+
+size([H|T]=Term, Seen0, Sum0) ->
+ case remember_term(Term, Seen0) of
+ seen -> {Sum0,Seen0};
+ Seen1 ->
+ {Sum,Seen} = size(H, Seen1, Sum0+2),
+ size(T, Seen, Sum)
+ end;
+size(Tuple, Seen0, Sum0) when is_tuple(Tuple) ->
+ case remember_term(Tuple, Seen0) of
+ seen -> {Sum0,Seen0};
+ Seen ->
+ Sum = Sum0 + 1 + tuple_size(Tuple),
+ tuple_size(1, tuple_size(Tuple), Tuple, Seen, Sum)
+ end;
+size(Term, Seen0, Sum) ->
+ case erts_debug:flat_size(Term) of
+ 0 -> {Sum,Seen0};
+ Sz ->
+ case remember_term(Term, Seen0) of
+ seen -> {Sum,Seen0};
+ Seen -> {Sum+Sz,Seen}
+ end
+ end.
+
+tuple_size(I, Sz, _, Seen, Sum) when I > Sz ->
+ {Sum,Seen};
+tuple_size(I, Sz, Tuple, Seen0, Sum0) ->
+ {Sum,Seen} = size(element(I, Tuple), Seen0, Sum0),
+ tuple_size(I+1, Sz, Tuple, Seen, Sum).
+
+remember_term(Term, Seen) ->
+ case gb_trees:lookup(Term, Seen) of
+ none -> gb_trees:insert(Term, [Term], Seen);
+ {value,Terms} ->
+ case is_term_seen(Term, Terms) of
+ false -> gb_trees:update(Term, [Term|Terms], Seen);
+ true -> seen
+ end
+ end.
+
+-spec is_term_seen(term(), [term()]) -> boolean().
+
+is_term_seen(Term, [H|T]) ->
+ case erts_debug:same(Term, H) of
+ true -> true;
+ false -> is_term_seen(Term, T)
+ end;
+is_term_seen(_, []) -> false.
+
+%% df(Mod) -- Disassemble Mod to file Mod.dis.
+%% df(Mod, Func) -- Disassemble Mod:Func/Any to file Mod_Func.dis.
+%% df(Mod, Func, Arity) -- Disassemble Mod:Func/Arity to file Mod_Func_Arity.dis.
+
+-type df_ret() :: 'ok' | {'error', {'badopen', module()}} | {'undef', module()}.
+
+-spec df(module()) -> df_ret().
+
+df(Mod) when is_atom(Mod) ->
+ try Mod:module_info(functions) of
+ Fs0 when is_list(Fs0) ->
+ Name = lists:concat([Mod, ".dis"]),
+ Fs = [{Mod,Func,Arity} || {Func,Arity} <- Fs0],
+ dff(Name, Fs)
+ catch _:_ -> {undef,Mod}
+ end.
+
+-spec df(module(), atom()) -> df_ret().
+
+df(Mod, Func) when is_atom(Mod), is_atom(Func) ->
+ try Mod:module_info(functions) of
+ Fs0 when is_list(Fs0) ->
+ Name = lists:concat([Mod, "_", Func, ".dis"]),
+ Fs = [{Mod,Func1,Arity} || {Func1,Arity} <- Fs0, Func1 =:= Func],
+ dff(Name, Fs)
+ catch _:_ -> {undef,Mod}
+ end.
+
+-spec df(module(), atom(), arity()) -> df_ret().
+
+df(Mod, Func, Arity) when is_atom(Mod), is_atom(Func) ->
+ try Mod:module_info(functions) of
+ Fs0 when is_list(Fs0) ->
+ Name = lists:concat([Mod, "_", Func, "_", Arity, ".dis"]),
+ Fs = [{Mod,Func1,Arity1} || {Func1,Arity1} <- Fs0,
+ Func1 =:= Func, Arity1 =:= Arity],
+ dff(Name, Fs)
+ catch _:_ -> {undef,Mod}
+ end.
+
+dff(File, Fs) when is_pid(File), is_list(Fs) ->
+ lists:foreach(fun(Mfa) ->
+ disassemble_function(File, Mfa),
+ io:nl(File)
+ end, Fs);
+dff(Name, Fs) when is_list(Name) ->
+ case file:open(Name, [write]) of
+ {ok,F} ->
+ try
+ dff(F, Fs)
+ after
+ file:close(F)
+ end;
+ {error,Reason} ->
+ {error,{badopen,Reason}}
+ end.
+
+disassemble_function(File, {_,_,_}=MFA) ->
+ cont_dis(File, erts_debug:disassemble(MFA), MFA).
+
+cont_dis(_, false, _) -> ok;
+cont_dis(File, {Addr,Str,MFA}, MFA) ->
+ io:put_chars(File, binary_to_list(Str)),
+ cont_dis(File, erts_debug:disassemble(Addr), MFA);
+cont_dis(_, {_,_,_}, _) -> ok.