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<title>src/Darcs/SignalHandler.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>-- Copyright (C) 2003 David Roundy</span>
<a name="line-2"></a><span class='hs-comment'>--</span>
<a name="line-3"></a><span class='hs-comment'>-- This program is free software; you can redistribute it and/or modify</span>
<a name="line-4"></a><span class='hs-comment'>-- it under the terms of the GNU General Public License as published by</span>
<a name="line-5"></a><span class='hs-comment'>-- the Free Software Foundation; either version 2, or (at your option)</span>
<a name="line-6"></a><span class='hs-comment'>-- any later version.</span>
<a name="line-7"></a><span class='hs-comment'>--</span>
<a name="line-8"></a><span class='hs-comment'>-- This program is distributed in the hope that it will be useful,</span>
<a name="line-9"></a><span class='hs-comment'>-- but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
<a name="line-10"></a><span class='hs-comment'>-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</span>
<a name="line-11"></a><span class='hs-comment'>-- GNU General Public License for more details.</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-comment'>-- You should have received a copy of the GNU General Public License</span>
<a name="line-14"></a><span class='hs-comment'>-- along with this program; see the file COPYING. If not, write to</span>
<a name="line-15"></a><span class='hs-comment'>-- the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,</span>
<a name="line-16"></a><span class='hs-comment'>-- Boston, MA 02110-1301, USA.</span>
<a name="line-17"></a>
<a name="line-18"></a><span class='hs-comment'>{-# OPTIONS_GHC -cpp -fglasgow-exts #-}</span>
<a name="line-19"></a><span class='hs-comment'>{-# LANGUAGE CPP #-}</span>
<a name="line-20"></a><span class='hs-comment'>-- , DeriveDataTypeable #-}</span>
<a name="line-21"></a>
<a name="line-22"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>SignalHandler</span> <span class='hs-layout'>(</span> <span class='hs-varid'>withSignalsHandled</span><span class='hs-layout'>,</span> <span class='hs-varid'>withSignalsBlocked</span><span class='hs-layout'>,</span>
<a name="line-23"></a> <span class='hs-varid'>catchInterrupt</span><span class='hs-layout'>,</span> <span class='hs-varid'>catchNonSignal</span><span class='hs-layout'>,</span>
<a name="line-24"></a> <span class='hs-varid'>tryNonSignal</span><span class='hs-layout'>,</span> <span class='hs-varid'>stdout_is_a_pipe</span> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-25"></a>
<a name="line-26"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>Error</span> <span class='hs-layout'>(</span> <span class='hs-varid'>isUserError</span><span class='hs-layout'>,</span> <span class='hs-varid'>ioeGetErrorString</span><span class='hs-layout'>,</span> <span class='hs-varid'>ioeGetFileName</span> <span class='hs-layout'>)</span>
<a name="line-27"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span> <span class='hs-layout'>(</span> <span class='hs-varid'>dynExceptions</span><span class='hs-layout'>,</span> <span class='hs-varid'>ioErrors</span><span class='hs-layout'>,</span> <span class='hs-varid'>catchJust</span><span class='hs-layout'>,</span> <span class='hs-conid'>Exception</span> <span class='hs-layout'>(</span> <span class='hs-conid'>IOException</span> <span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-28"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Exit</span> <span class='hs-layout'>(</span> <span class='hs-varid'>exitWith</span><span class='hs-layout'>,</span> <span class='hs-conid'>ExitCode</span> <span class='hs-layout'>(</span> <span class='hs-conid'>ExitFailure</span> <span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-29"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Concurrent</span> <span class='hs-layout'>(</span> <span class='hs-conid'>ThreadId</span><span class='hs-layout'>,</span> <span class='hs-varid'>myThreadId</span> <span class='hs-layout'>)</span>
<a name="line-30"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span> <span class='hs-layout'>(</span> <span class='hs-varid'>catchDyn</span><span class='hs-layout'>,</span> <span class='hs-varid'>throwDyn</span><span class='hs-layout'>,</span> <span class='hs-varid'>throwDynTo</span><span class='hs-layout'>,</span> <span class='hs-varid'>block</span> <span class='hs-layout'>)</span>
<a name="line-31"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Posix</span><span class='hs-varop'>.</span><span class='hs-conid'>Files</span> <span class='hs-layout'>(</span> <span class='hs-varid'>getFdStatus</span><span class='hs-layout'>,</span> <span class='hs-varid'>isNamedPipe</span> <span class='hs-layout'>)</span>
<a name="line-32"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Posix</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span> <span class='hs-layout'>(</span> <span class='hs-varid'>stdOutput</span> <span class='hs-layout'>)</span>
<a name="line-33"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Dynamic</span> <span class='hs-layout'>(</span> <span class='hs-conid'>Typeable</span><span class='hs-layout'>,</span> <span class='hs-varid'>fromDynamic</span> <span class='hs-layout'>)</span>
<a name="line-34"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span> <span class='hs-layout'>(</span> <span class='hs-varid'>hPutStrLn</span><span class='hs-layout'>,</span> <span class='hs-varid'>stderr</span> <span class='hs-layout'>)</span>
<a name="line-35"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span> <span class='hs-layout'>(</span> <span class='hs-varid'>when</span> <span class='hs-layout'>)</span>
<a name="line-36"></a>
<a name="line-37"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Workaround</span> <span class='hs-layout'>(</span> <span class='hs-varid'>installHandler</span><span class='hs-layout'>,</span> <span class='hs-varid'>raiseSignal</span><span class='hs-layout'>,</span> <span class='hs-conid'>Handler</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-conid'>Signal</span><span class='hs-layout'>,</span>
<a name="line-38"></a> <span class='hs-varid'>sigINT</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigHUP</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigABRT</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigALRM</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigTERM</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigPIPE</span> <span class='hs-layout'>)</span>
<a name="line-39"></a><span class='hs-cpp'>#ifdef WIN32</span>
<a name="line-40"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>CtrlC</span> <span class='hs-layout'>(</span> <span class='hs-varid'>withCtrlCHandler</span> <span class='hs-layout'>)</span>
<a name="line-41"></a><span class='hs-cpp'>#endif</span>
<a name="line-42"></a>
<a name="line-43"></a><a name="stdout_is_a_pipe"></a><span class='hs-definition'>stdout_is_a_pipe</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-conid'>Bool</span>
<a name="line-44"></a><span class='hs-definition'>stdout_is_a_pipe</span>
<a name="line-45"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>catchJust</span> <span class='hs-varid'>ioErrors</span>
<a name="line-46"></a> <span class='hs-layout'>(</span><span class='hs-keyword'>do</span> <span class='hs-varid'>stat</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getFdStatus</span> <span class='hs-varid'>stdOutput</span>
<a name="line-47"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>isNamedPipe</span> <span class='hs-varid'>stat</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-48"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span>
<a name="line-49"></a>
<a name="line-50"></a><a name="withSignalsHandled"></a><span class='hs-definition'>withSignalsHandled</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-51"></a><a name="SignalException"></a><span class='hs-keyword'>newtype</span> <span class='hs-conid'>SignalException</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>SignalException</span> <span class='hs-conid'>Signal</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Typeable</span><span class='hs-layout'>)</span>
<a name="line-52"></a>
<a name="line-53"></a><span class='hs-definition'>withSignalsHandled</span> <span class='hs-varid'>job</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-54"></a> <span class='hs-varid'>thid</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>myThreadId</span>
<a name="line-55"></a> <span class='hs-varid'>mapM_</span> <span class='hs-layout'>(</span><span class='hs-varid'>ih</span> <span class='hs-varid'>thid</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>sigINT</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigHUP</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigABRT</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigTERM</span><span class='hs-layout'>,</span> <span class='hs-varid'>sigPIPE</span><span class='hs-keyglyph'>]</span>
<a name="line-56"></a> <span class='hs-varid'>catchJust</span> <span class='hs-varid'>just_usererrors</span> <span class='hs-layout'>(</span><span class='hs-varid'>job'</span> <span class='hs-varid'>thid</span> <span class='hs-varop'>`catchSignal`</span> <span class='hs-varid'>defaults</span><span class='hs-layout'>)</span>
<a name="line-57"></a> <span class='hs-varid'>die_with_string</span>
<a name="line-58"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>defaults</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigINT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ew</span> <span class='hs-varid'>s</span> <span class='hs-str'>"Interrupted!"</span>
<a name="line-59"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigHUP</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ew</span> <span class='hs-varid'>s</span> <span class='hs-str'>"HUP"</span>
<a name="line-60"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigABRT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ew</span> <span class='hs-varid'>s</span> <span class='hs-str'>"ABRT"</span>
<a name="line-61"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigTERM</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ew</span> <span class='hs-varid'>s</span> <span class='hs-str'>"TERM"</span>
<a name="line-62"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigPIPE</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>exitWith</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ExitFailure</span> <span class='hs-varop'>$</span> <span class='hs-num'>1</span>
<a name="line-63"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ew</span> <span class='hs-varid'>s</span> <span class='hs-str'>"Unhandled signal!"</span>
<a name="line-64"></a> <span class='hs-varid'>ew</span> <span class='hs-varid'>sig</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>hPutStrLn</span> <span class='hs-varid'>stderr</span> <span class='hs-varop'>$</span> <span class='hs-layout'>(</span><span class='hs-str'>"withSignalsHandled: "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-65"></a> <span class='hs-varid'>resethandler</span> <span class='hs-varid'>sig</span>
<a name="line-66"></a> <span class='hs-varid'>raiseSignal</span> <span class='hs-varid'>sig</span> <span class='hs-comment'>-- ensure that our caller knows how we died</span>
<a name="line-67"></a> <span class='hs-varid'>exitWith</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ExitFailure</span> <span class='hs-varop'>$</span> <span class='hs-num'>1</span>
<a name="line-68"></a> <span class='hs-varid'>die_with_string</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>take</span> <span class='hs-num'>6</span> <span class='hs-varid'>e</span> <span class='hs-varop'>==</span> <span class='hs-str'>"STDOUT"</span> <span class='hs-keyglyph'>=</span>
<a name="line-69"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>is_pipe</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>stdout_is_a_pipe</span>
<a name="line-70"></a> <span class='hs-varid'>when</span> <span class='hs-layout'>(</span><span class='hs-varid'>not</span> <span class='hs-varid'>is_pipe</span><span class='hs-layout'>)</span> <span class='hs-varop'>$</span>
<a name="line-71"></a> <span class='hs-varid'>hPutStrLn</span> <span class='hs-varid'>stderr</span> <span class='hs-varop'>$</span> <span class='hs-str'>"\ndarcs failed: "</span><span class='hs-varop'>++</span><span class='hs-varid'>drop</span> <span class='hs-num'>6</span> <span class='hs-varid'>e</span>
<a name="line-72"></a> <span class='hs-varid'>exitWith</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ExitFailure</span> <span class='hs-varop'>$</span> <span class='hs-num'>2</span>
<a name="line-73"></a> <span class='hs-varid'>die_with_string</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>hPutStrLn</span> <span class='hs-varid'>stderr</span> <span class='hs-varop'>$</span> <span class='hs-str'>"\ndarcs failed: "</span><span class='hs-varop'>++</span><span class='hs-varid'>e</span>
<a name="line-74"></a> <span class='hs-varid'>exitWith</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ExitFailure</span> <span class='hs-varop'>$</span> <span class='hs-num'>2</span>
<a name="line-75"></a><span class='hs-cpp'>#ifdef WIN32</span>
<a name="line-76"></a> <span class='hs-varid'>job'</span> <span class='hs-varid'>thid</span> <span class='hs-keyglyph'>=</span>
<a name="line-77"></a> <span class='hs-varid'>withCtrlCHandler</span> <span class='hs-layout'>(</span><span class='hs-varid'>throwDynTo</span> <span class='hs-varid'>thid</span> <span class='hs-varop'>$</span> <span class='hs-conid'>SignalException</span> <span class='hs-varid'>sigINT</span><span class='hs-layout'>)</span> <span class='hs-varid'>job</span>
<a name="line-78"></a><span class='hs-cpp'>#else</span>
<a name="line-79"></a> <span class='hs-varid'>job'</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>job</span>
<a name="line-80"></a><span class='hs-cpp'>#endif</span>
<a name="line-81"></a>
<a name="line-82"></a><a name="resethandler"></a><span class='hs-definition'>resethandler</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Signal</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-83"></a><span class='hs-definition'>resethandler</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>installHandler</span> <span class='hs-varid'>s</span> <span class='hs-conid'>Default</span> <span class='hs-conid'>Nothing</span>
<a name="line-84"></a> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-85"></a>
<a name="line-86"></a><a name="ih"></a><span class='hs-definition'>ih</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>ThreadId</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Signal</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-87"></a><span class='hs-definition'>ih</span> <span class='hs-varid'>thid</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span>
<a name="line-88"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>installHandler</span> <span class='hs-varid'>s</span> <span class='hs-layout'>(</span><span class='hs-conid'>Catch</span> <span class='hs-varop'>$</span> <span class='hs-varid'>throwDynTo</span> <span class='hs-varid'>thid</span> <span class='hs-varop'>$</span> <span class='hs-conid'>SignalException</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-conid'>Nothing</span>
<a name="line-89"></a> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-90"></a>
<a name="line-91"></a><a name="catchSignal"></a><span class='hs-definition'>catchSignal</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-conid'>Signal</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-92"></a><span class='hs-definition'>catchSignal</span> <span class='hs-varid'>job</span> <span class='hs-varid'>handler</span> <span class='hs-keyglyph'>=</span>
<a name="line-93"></a> <span class='hs-varid'>job</span> <span class='hs-varop'>`</span><span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-varid'>catchDyn</span><span class='hs-varop'>`</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-conid'>SignalException</span> <span class='hs-varid'>sig</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>handler</span> <span class='hs-varid'>sig</span><span class='hs-layout'>)</span>
<a name="line-94"></a>
<a name="line-95"></a><span class='hs-comment'>-- catchNonSignal is a drop-in replacement for Control.Exception.catch, which allows</span>
<a name="line-96"></a><span class='hs-comment'>-- us to catch anything but a signal. Useful for situations where we want</span>
<a name="line-97"></a><span class='hs-comment'>-- don't want to inhibit ctrl-C.</span>
<a name="line-98"></a>
<a name="line-99"></a><a name="catchNonSignal"></a><span class='hs-definition'>catchNonSignal</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-100"></a><span class='hs-definition'>catchNonSignal</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-varid'>catchJust</span> <span class='hs-varid'>notSig</span>
<a name="line-101"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>notSig</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>dynExceptions</span> <span class='hs-varid'>x</span> <span class='hs-keyword'>of</span>
<a name="line-102"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-103"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>d</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-varid'>fromDynamic</span> <span class='hs-varid'>d</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>SignalException</span> <span class='hs-keyword'>of</span>
<a name="line-104"></a> <span class='hs-conid'>Just</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Nothing</span>
<a name="line-105"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-106"></a>
<a name="line-107"></a><a name="catchInterrupt"></a><span class='hs-definition'>catchInterrupt</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-108"></a><span class='hs-definition'>catchInterrupt</span> <span class='hs-varid'>job</span> <span class='hs-varid'>handler</span> <span class='hs-keyglyph'>=</span>
<a name="line-109"></a> <span class='hs-varid'>job</span> <span class='hs-varop'>`catchSignal`</span> <span class='hs-varid'>h</span>
<a name="line-110"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>h</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigINT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>handler</span>
<a name="line-111"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>throwDyn</span> <span class='hs-layout'>(</span><span class='hs-conid'>SignalException</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-112"></a>
<a name="line-113"></a><a name="tryNonSignal"></a><span class='hs-definition'>tryNonSignal</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Either</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-114"></a><span class='hs-definition'>tryNonSignal</span> <span class='hs-varid'>j</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varop'>`fmap`</span> <span class='hs-varid'>j</span><span class='hs-layout'>)</span> <span class='hs-varop'>`catchNonSignal`</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>e</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>Left</span> <span class='hs-varid'>e</span><span class='hs-layout'>)</span>
<a name="line-115"></a>
<a name="line-116"></a><a name="just_usererrors"></a><span class='hs-definition'>just_usererrors</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>String</span>
<a name="line-117"></a><span class='hs-definition'>just_usererrors</span> <span class='hs-layout'>(</span><span class='hs-conid'>IOException</span> <span class='hs-varid'>e</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>isUserError</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-varid'>ioeGetErrorString</span> <span class='hs-varid'>e</span>
<a name="line-118"></a><span class='hs-definition'>just_usererrors</span> <span class='hs-layout'>(</span><span class='hs-conid'>IOException</span> <span class='hs-varid'>e</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>ioeGetFileName</span> <span class='hs-varid'>e</span> <span class='hs-varop'>==</span> <span class='hs-conid'>Just</span> <span class='hs-str'>"<stdout>"</span>
<a name="line-119"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-str'>"STDOUT"</span><span class='hs-varop'>++</span><span class='hs-varid'>ioeGetErrorString</span> <span class='hs-varid'>e</span>
<a name="line-120"></a><span class='hs-definition'>just_usererrors</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-121"></a>
<a name="line-122"></a><a name="withSignalsBlocked"></a><span class='hs-definition'>withSignalsBlocked</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-123"></a><span class='hs-definition'>withSignalsBlocked</span> <span class='hs-varid'>job</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>block</span> <span class='hs-varid'>job</span><span class='hs-layout'>)</span> <span class='hs-varop'>`catchSignal`</span> <span class='hs-varid'>couldnt_do</span>
<a name="line-124"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>couldnt_do</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigINT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>oops</span> <span class='hs-str'>"interrupt"</span>
<a name="line-125"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigHUP</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>oops</span> <span class='hs-str'>"HUP"</span>
<a name="line-126"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigABRT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>oops</span> <span class='hs-str'>"ABRT"</span>
<a name="line-127"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigALRM</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>oops</span> <span class='hs-str'>"ALRM"</span>
<a name="line-128"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigTERM</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>oops</span> <span class='hs-str'>"TERM"</span>
<a name="line-129"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span> <span class='hs-varop'>==</span> <span class='hs-varid'>sigPIPE</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-130"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>oops</span> <span class='hs-str'>"unknown signal"</span>
<a name="line-131"></a> <span class='hs-varid'>oops</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>hPutStrLn</span> <span class='hs-varid'>stderr</span> <span class='hs-varop'>$</span> <span class='hs-str'>"Couldn't handle "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>s</span> <span class='hs-varop'>++</span>
<a name="line-132"></a> <span class='hs-str'>" since darcs was in a sensitive job."</span>
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