1error_handler(3)           Erlang Module Definition           error_handler(3)
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NAME

6       error_handler - Default system error handler.
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DESCRIPTION

9       This module defines what happens when certain types of errors occur.
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EXPORTS

12       raise_undef_exception(Module, Function, Args) -> no_return()
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14              Types:
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16                 Module = Function = atom()
17                 Args = list()
18                    A (possibly empty) list of arguments Arg1,..,ArgN
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20              Raises  an  undef  exception  with a stacktrace, indicating that
21              Module:Function/N is undefined.
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23       undefined_function(Module, Function, Args) -> any()
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25              Types:
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27                 Module = Function = atom()
28                 Args = list()
29                    A (possibly empty) list of arguments Arg1,..,ArgN
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31              This function is called by the runtime system if a call is  made
32              to Module:Function(Arg1,.., ArgN) and Module:Function/N is unde‐
33              fined. Notice that this function is evaluated inside the process
34              making the original call.
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36              This  function first attempts to autoload Module. If that is not
37              possible, an undef exception is raised.
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39              If it is possible to load Module and function Function/N is  ex‐
40              ported, it is called.
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42              Otherwise,  if  function  '$handle_undefined_function'/2  is ex‐
43              ported, it is called  as  '$handle_undefined_function'(Function,
44              Args).
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46          Warning:
47              Defining  '$handle_undefined_function'/2 in ordinary application
48              code is highly discouraged. It is very easy to make  subtle  er‐
49              rors  that  can  take a long time to debug. Furthermore, none of
50              the tools for static code analysis (such as Dialyzer  and  Xref)
51              supports  the  use of '$handle_undefined_function'/2 and no such
52              support will be added. Only use this function after having care‐
53              fully  considered  other, less dangerous, solutions. One example
54              of potential legitimate use is creating stubs for other sub-sys‐
55              tems during testing and debugging.
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58              Otherwise an undef exception is raised.
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60       undefined_lambda(Module, Fun, Args) -> term()
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62              Types:
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64                 Module = atom()
65                 Fun = function()
66                 Args = list()
67                    A (possibly empty) list of arguments Arg1,..,ArgN
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69              This  function  is  evaluated  if a call is made to Fun(Arg1,..,
70              ArgN) when the module defining the fun is not loaded. The  func‐
71              tion is evaluated inside the process making the original call.
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73              If Module is interpreted, the interpreter is invoked and the re‐
74              turn value of the interpreted Fun(Arg1,..,  ArgN)  call  is  re‐
75              turned.
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77              Otherwise,  it  returns,  if  possible,  the value of apply(Fun,
78              Args) after an attempt is made to autoload Module.  If  this  is
79              not possible, the call fails with exit reason undef.
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NOTES

82       The  code  in  error_handler is complex. Do not change it without fully
83       understanding the interaction  between  the  error  handler,  the  init
84       process of the code server, and the I/O mechanism of the code.
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86       Code changes that seem small can cause a deadlock, as unforeseen conse‐
87       quences can occur. The use of input is dangerous in this type of code.
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91Ericsson AB                     kernel 8.5.4.2                error_handler(3)