view src/plugincandidates.cpp @ 64:e839338d3869 tip

Further Windows fix

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
/*
  Copyright (c) 2016-2018 Queen Mary, University of London

  Permission is hereby granted, free of charge, to any person
  obtaining a copy of this software and associated documentation
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  modify, merge, publish, distribute, sublicense, and/or sell copies
  of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

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#include "plugincandidates.h"

#include "../version.h"

#include <set>
#include <stdexcept>
#include <iostream>

#include <QProcess>
#include <QDir>
#include <QElapsedTimer>

#if defined(_WIN32)
#define PLUGIN_GLOB "*.dll"
#elif defined(__APPLE__)
#define PLUGIN_GLOB "*.dylib *.so"
#else
#define PLUGIN_GLOB "*.so"
#endif

using namespace std;

PluginCandidates::PluginCandidates(string helperExecutableName) :
    m_helper(helperExecutableName),
    m_logCallback(nullptr)
{
}

void
PluginCandidates::setLogCallback(LogCallback *cb)
{
    m_logCallback = cb;
}

vector<string>
PluginCandidates::getCandidateLibrariesFor(string tag) const
{
    if (m_candidates.find(tag) == m_candidates.end()) return {};
    else return m_candidates.at(tag);
}

vector<PluginCandidates::FailureRec>
PluginCandidates::getFailedLibrariesFor(string tag) const
{
    if (m_failures.find(tag) == m_failures.end()) return {};
    else return m_failures.at(tag);
}

void
PluginCandidates::log(string message)
{
    if (m_logCallback) {
        m_logCallback->log("PluginCandidates: " + message);
    } else {
        cerr << "PluginCandidates: " << message << endl;
    }
}

vector<string>
PluginCandidates::getLibrariesInPath(vector<string> path)
{
    vector<string> candidates;

    for (string dirname: path) {

        log("Scanning directory " + dirname);

        QDir dir(dirname.c_str(), PLUGIN_GLOB,
                 QDir::Name | QDir::IgnoreCase,
                 QDir::Files | QDir::Readable);

        for (unsigned int i = 0; i < dir.count(); ++i) {
            QString soname = dir.filePath(dir[i]);
            // NB this means the library names passed to the helper
            // are UTF-8 encoded
            candidates.push_back(soname.toStdString());
        }
    }

    return candidates;
}

void
PluginCandidates::scan(string tag,
                       vector<string> pluginPath,
                       string descriptorSymbolName)
{
    string helperVersion = getHelperCompatibilityVersion();
    if (helperVersion != CHECKER_COMPATIBILITY_VERSION) {
        log("Wrong plugin checker helper version found: expected v" +
            string(CHECKER_COMPATIBILITY_VERSION) + ", found v" +
            helperVersion);
        throw runtime_error("wrong version of plugin load helper found");
    }
    
    vector<string> libraries = getLibrariesInPath(pluginPath);
    vector<string> remaining = libraries;

    int runlimit = 20;
    int runcount = 0;
    
    vector<string> result;
    
    while (result.size() < libraries.size() && runcount < runlimit) {
        vector<string> output = runHelper(remaining, descriptorSymbolName);
        result.insert(result.end(), output.begin(), output.end());
        int shortfall = int(remaining.size()) - int(output.size());
        if (shortfall > 0) {
            // Helper bailed out for some reason presumably associated
            // with the plugin following the last one it reported
            // on. Add a failure entry for that one and continue with
            // the following ones.
            string failed = *(remaining.rbegin() + shortfall - 1);
            log("Helper output ended before result for plugin " + failed);
            result.push_back("FAILURE|" + failed + "|Plugin load check failed or timed out");
            remaining = vector<string>
                (remaining.rbegin(), remaining.rbegin() + shortfall - 1);
        }
        ++runcount;
    }

    recordResult(tag, result);
}

string
PluginCandidates::getHelperCompatibilityVersion()
{
    QProcess process;
    process.setReadChannel(QProcess::StandardOutput);
    process.setProcessChannelMode(QProcess::ForwardedErrorChannel);
    process.start(m_helper.c_str(), { "--version" });

    if (!process.waitForStarted()) {
        QProcess::ProcessError err = process.error();
        if (err == QProcess::FailedToStart) {
            std::cerr << "Unable to start helper process " << m_helper
                      << std::endl;
        } else if (err == QProcess::Crashed) {
            std::cerr << "Helper process " << m_helper
                      << " crashed on startup" << std::endl;
        } else {
            std::cerr << "Helper process " << m_helper
                      << " failed on startup with error code "
                      << err << std::endl;
        }
        throw runtime_error("plugin load helper failed to start");
    }
    process.waitForFinished();

    QByteArray output = process.readAllStandardOutput();
    while (output.endsWith('\n') || output.endsWith('\r')) {
        output.chop(1);
    }

    string versionString = QString(output).toStdString();
    log("Read version string from helper: " + versionString);
    return versionString;
}

vector<string>
PluginCandidates::runHelper(vector<string> libraries, string descriptor)
{
    vector<string> output;

    log("Running helper " + m_helper + " with following library list:");
    for (auto &lib: libraries) log(lib);

    QProcess process;
    process.setReadChannel(QProcess::StandardOutput);

    if (m_logCallback) {
        log("Log callback is set: using separate-channels mode to gather stderr");
        process.setProcessChannelMode(QProcess::SeparateChannels);
    } else {
        process.setProcessChannelMode(QProcess::ForwardedErrorChannel);
    }
    
    process.start(m_helper.c_str(), { descriptor.c_str() });
    
    if (!process.waitForStarted()) {
        QProcess::ProcessError err = process.error();
        if (err == QProcess::FailedToStart) {
            std::cerr << "Unable to start helper process " << m_helper
                      << std::endl;
        } else if (err == QProcess::Crashed) {
            std::cerr << "Helper process " << m_helper
                      << " crashed on startup" << std::endl;
        } else {
            std::cerr << "Helper process " << m_helper
                      << " failed on startup with error code "
                      << err << std::endl;
        }
        logErrors(&process);
        throw runtime_error("plugin load helper failed to start");
    }

    log("Helper " + m_helper + " started OK");
    logErrors(&process);
    
    for (auto &lib: libraries) {
        process.write(lib.c_str(), lib.size());
        process.write("\n", 1);
    }

    QElapsedTimer t;
    t.start();
    int timeout = 15000; // ms

    const int buflen = 4096;
    bool done = false;
    
    while (!done) {
        char buf[buflen];
        qint64 linelen = process.readLine(buf, buflen);
        if (linelen > 0) {
            output.push_back(buf);
            done = (output.size() == libraries.size());
        } else if (linelen < 0) {
            // error case
            log("Received error code while reading from helper");
            done = true;
        } else {
            // no error, but no line read (could just be between
            // lines, or could be eof)
            done = (process.state() == QProcess::NotRunning);
            if (!done) {
                if (t.elapsed() > timeout) {
                    // this is purely an emergency measure
                    log("Timeout: helper took too long, killing it");
                    process.kill();
                    done = true;
                } else {
                    process.waitForReadyRead(200);
                }
            }
        }
        logErrors(&process);
    }

    if (process.state() != QProcess::NotRunning) {
        process.close();
        process.waitForFinished();
        logErrors(&process);
    }

    log("Helper completed");
    
    return output;
}

void
PluginCandidates::logErrors(QProcess *p)
{
    p->setReadChannel(QProcess::StandardError);

    qint64 byteCount = p->bytesAvailable();
    if (byteCount == 0) {
        p->setReadChannel(QProcess::StandardOutput);
        return;
    }

    QByteArray buffer = p->read(byteCount);
    while (buffer.endsWith('\n') || buffer.endsWith('\r')) {
        buffer.chop(1);
    }
    std::string str(buffer.constData(), buffer.size());
    log("Helper stderr output follows:\n" + str);
    log("Helper stderr output ends");
    
    p->setReadChannel(QProcess::StandardOutput);
}

void
PluginCandidates::recordResult(string tag, vector<string> result)
{
    for (auto &r: result) {

        QString s(r.c_str());
        QStringList bits = s.split("|");

        log(("Read output line from helper: " + s.trimmed()).toStdString());
        
        if (bits.size() < 2 || bits.size() > 3) {
            log("Invalid output line (wrong number of |-separated fields)");
            continue;
        }

        string status = bits[0].toStdString();
        
        string library = bits[1].toStdString();
        if (bits.size() == 2) {
            library = bits[1].trimmed().toStdString();
        }

        if (status == "SUCCESS") {
            m_candidates[tag].push_back(library);

        } else if (status == "FAILURE") {
        
            QString messageAndCode = "";
            if (bits.size() > 2) {
                messageAndCode = bits[2].trimmed();
            }

            PluginCheckCode code = PluginCheckCode::FAIL_OTHER;
            string message = "";

            QRegExp codeRE("^(.*) *\\[([0-9]+)\\]$");
            if (codeRE.exactMatch(messageAndCode)) {
                QStringList caps(codeRE.capturedTexts());
                if (caps.length() == 3) {
                    message = caps[1].toStdString();
                    code = PluginCheckCode(caps[2].toInt());
                    log("Split failure report into message and failure code "
                        + caps[2].toStdString());
                } else {
                    log("Unable to split out failure code from report");
                }
            } else {
                log("Failure message does not give a failure code");
            }

            if (message == "") {
                message = messageAndCode.toStdString();
            }

            m_failures[tag].push_back({ library, code, message });

        } else {
            log("Unexpected status \"" + status + "\" in output line");
        }
    }
}