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POError apparently raised by not yet executed code
 

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  1. POError apparently raised by not yet executed code
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    <p>I'm learning c++ by writing a program to convert MIDI files to <a href="http://lilypond.org" rel="nofollow">Lilypond</a> source files. My program is composed by two main parts:</p> <ul> <li>a MIDI file parser, that creates an object called MidiFile.</li> <li>a converter that takes a MidiFile objects and converts it to a Lilypond source.</li> </ul> <p>Today I've started coding the converter, and while I was testing it a strange error occurred: the program dies after an exception being thrown, more specifically a HeaderError, that means that the header chunk in the MIDI file is not as expected. It wouldn't seem that strange, but this error shows up only if I add a line of code after the buggy code! I add the main() function to better explain myself</p> <pre><code>#include &lt;iostream&gt; #include "midiToLyConverter.hpp" int main(){ // a queue to store notes that have not yet been shut down using MidiToLyConverter::Converter::NoteQueue; // representation of a note using MidiToLyConverter::Converter::Note; // the converter class using MidiToLyConverter::Converter::Converter; // the midifile class using Midi::MidiFile; // representation of a midi track using Midi::MidiTrack; // representation of a midi event using Midi::MidiEvents::Event; Parser::Parser parser = Parser::Parser(); // parser class parser.buildMidiFile(); // builds the midi file from a .mid Midi::MidiFile* midiFile = parser.getMidiFile(); // gets the MidiFile object // iterates over all the tracks in the MidiFile while(midiFile-&gt;hasNext()){ std::cout&lt;&lt; "==========\n"; MidiTrack* track = midiFile-&gt;nextTrack(); // iterates over all events in a track while(track-&gt;hasNext()){ Event* event = track-&gt;nextEvent(); if (event-&gt;getEventType() == Midi::MidiEvents::NOTE_ON || event-&gt;getEventType() == Midi::MidiEvents::NOTE_OFF ) // print the event if it's a note on or off event-&gt;print(); } } return 0; } </code></pre> <p>With my main() like this, everything works properly, but, if I add something between buildMidiFile and the while loop, the function buildMidiFile throws the exception!!! Even if it's a completely unrelated instruction!</p> <pre><code>#include &lt;iostream&gt; #include "midiToLyConverter.hpp" int main(){ using MidiToLyConverter::Converter::NoteQueue; using MidiToLyConverter::Converter::Note; using MidiToLyConverter::Converter::Converter; using Midi::MidiFile; using Midi::MidiTrack; using Midi::MidiEvents::Event; Parser::Parser parser = Parser::Parser(); // parser class parser.buildMidiFile(); // THE EXCEPTION IS THROWN HERE Midi::MidiFile* midiFile = parser.getMidiFile(); // gets the MidiFile object // adding this causes the exception to be thrown by the function // buildMidiFile() called 5 lines above! std::vector&lt;bool&gt;* vec = new std::vector&lt;bool&gt;(); // iterates over all the tracks in the MidiFile while(midiFile-&gt;hasNext()){ std::cout&lt;&lt; "==========\n"; MidiTrack* track = midiFile-&gt;nextTrack(); // iterates over all events in a track while(track-&gt;hasNext()){ Event* event = track-&gt;nextEvent(); if (event-&gt;getEventType() == Midi::MidiEvents::NOTE_ON || event-&gt;getEventType() == Midi::MidiEvents::NOTE_OFF ) // print the event if it's a note on or off event-&gt;print(); } } return 0; } </code></pre> <p>I can't explain myself how this is possible. So if anyone has ideas or advices, all the help would be greatly appreciated :) If it's helpful I can post the source code for other classes and/or functions.</p>
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    1. PTQuestion
    1. USMatteo Ceccarello
    1. USMatteo Ceccarello
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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    1. VO
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      1. POError apparently raised by not yet executed code
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
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      1. POError apparently raised by not yet executed code
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
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      1. POError apparently raised by not yet executed code
      1. This table or related slice is empty.
      1. VTUpMod
    1. COSmells like a memory overwrite somewhere in the code that does get called. By declaring a new local variable you're changing the stack layout and different stuff gets overwritten now.
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      1. POError apparently raised by not yet executed code
      1. USTorp
    2. COSounds like stack corruption to me, but I can't see where or how.
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      1. POError apparently raised by not yet executed code
      1. USJustin
    3. COThis could be a problem `Parser::Parser parser = Parser::Parser();` as it creates a temporary `Parser` object and copies that to `parser`. Try with just `Parser parser;`.
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      1. POError apparently raised by not yet executed code
      1. USBo Persson
 

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