Core: Consolidate QProcess error reporting

Introduce two methods to set set error and errorString, and optionally
emit the error() signal. This also fixes two places where errorString
hasn't been set previously.

Change-Id: Ib7c27ff2daff898745e8e20ff8f11eaae568697f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

5 files changed, 78 insertions, 79 deletions

diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index da6e0c87af..8f7f164f76 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -897,6 +897,48 @@ void QProcessPrivate::cleanup()
 
 /*!
     \internal
+*/
+void QProcessPrivate::setError(QProcess::ProcessError error, const QString &description)
+{
+    processError = error;
+    if (description.isEmpty()) {
+        switch (error) {
+        case QProcess::FailedToStart:
+            errorString = QProcess::tr("Process failed to start");
+        case QProcess::Crashed:
+            errorString = QProcess::tr("Process crashed");
+            break;
+        case QProcess::Timedout:
+            errorString = QProcess::tr("Process operation timed out");
+            break;
+        case QProcess::ReadError:
+            errorString = QProcess::tr("Error reading from process");
+            break;
+        case QProcess::WriteError:
+            errorString = QProcess::tr("Error writing to process");
+            break;
+        case QProcess::UnknownError:
+            errorString.clear();
+            break;
+        }
+    } else {
+        errorString = description;
+    }
+}
+
+/*!
+    \internal
+*/
+void QProcessPrivate::setErrorAndEmit(QProcess::ProcessError error, const QString &description)
+{
+    Q_Q(QProcess);
+    Q_ASSERT(error != QProcess::UnknownError);
+    setError(error, description);
+    emit q->error(processError);
+}
+
+/*!
+    \internal
     Returns true if we emitted readyRead().
 */
 bool QProcessPrivate::tryReadFromChannel(Channel *channel)
@@ -918,9 +960,7 @@ bool QProcessPrivate::tryReadFromChannel(Channel *channel)
         return false;
     }
     if (readBytes == -1) {
-        processError = QProcess::ReadError;
-        q->setErrorString(QProcess::tr("Error reading from process"));
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::ReadError);
 #if defined QPROCESS_DEBUG
         qDebug("QProcessPrivate::tryReadFromChannel(%d), failed to read from the process", channel - &stdinChannel);
 #endif
@@ -1004,9 +1044,7 @@ bool QProcessPrivate::_q_canWrite()
                                       stdinChannel.buffer.nextDataBlockSize());
     if (written < 0) {
         closeChannel(&stdinChannel);
-        processError = QProcess::WriteError;
-        q->setErrorString(QProcess::tr("Error writing to process"));
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::WriteError);
         return false;
     }
 
@@ -1075,9 +1113,7 @@ bool QProcessPrivate::_q_processDied()
 
     if (crashed) {
         exitStatus = QProcess::CrashExit;
-        processError = QProcess::Crashed;
-        q->setErrorString(QProcess::tr("Process crashed"));
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::Crashed);
     } else {
 #ifdef QPROCESS_USE_SPAWN
         // if we're using posix_spawn, waitForStarted always succeeds.
@@ -1085,8 +1121,8 @@ bool QProcessPrivate::_q_processDied()
         // 127 if anything prevents the target program from starting.
         // http://pubs.opengroup.org/onlinepubs/009695399/functions/posix_spawn.html
         if (exitStatus == QProcess::NormalExit && exitCode == 127) {
-            processError = QProcess::FailedToStart;
-            q->setErrorString(QProcess::tr("Process failed to start (spawned process exited with code 127)"));
+            setError(QProcess::FailedToStart,
+                     QProcess::tr("Process failed to start (spawned process exited with code 127)"));
         }
 #endif
     }
@@ -1130,8 +1166,7 @@ bool QProcessPrivate::_q_startupNotification()
     }
 
     q->setProcessState(QProcess::NotRunning);
-    processError = QProcess::FailedToStart;
-    emit q->error(processError);
+    setErrorAndEmit(QProcess::FailedToStart);
 #ifdef Q_OS_UNIX
     // make sure the process manager removes this entry
     waitForDeadChild();
@@ -1939,9 +1974,7 @@ qint64 QProcess::writeData(const char *data, qint64 len)
 #if defined(Q_OS_WINCE)
     Q_UNUSED(data);
     Q_UNUSED(len);
-    d->processError = QProcess::WriteError;
-    setErrorString(tr("Error writing to process"));
-    emit error(d->processError);
+    d->setErrorAndEmit(QProcess::WriteError);
     return -1;
 #endif
 
@@ -2220,9 +2253,7 @@ void QProcess::start(const QString &command, OpenMode mode)
     QStringList args = parseCombinedArgString(command);
     if (args.isEmpty()) {
         Q_D(QProcess);
-        d->processError = QProcess::FailedToStart;
-        setErrorString(tr("No program defined"));
-        emit error(d->processError);
+        d->setErrorAndEmit(QProcess::FailedToStart, tr("No program defined"));
         return;
     }
 
diff --git a/src/corelib/io/qprocess_p.h b/src/corelib/io/qprocess_p.h
index f6bd64fb87..fc6b5345d1 100644
--- a/src/corelib/io/qprocess_p.h
+++ b/src/corelib/io/qprocess_p.h
@@ -383,6 +383,8 @@ public:
     qint64 writeToStdin(const char *data, qint64 maxlen);
 
     void cleanup();
+    void setError(QProcess::ProcessError error, const QString &description = QString());
+    void setErrorAndEmit(QProcess::ProcessError error, const QString &description = QString());
 
 #ifdef Q_OS_BLACKBERRY
     QList<QSocketNotifier *> defaultNotifiers() const;
diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 5ea3bf8982..47611d4b00 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -203,8 +203,8 @@ bool QProcessPrivate::openChannel(Channel &channel)
             channel.pipe[1] = -1;
             if ( (channel.pipe[0] = qt_safe_open(fname, O_RDONLY)) != -1)
                 return true;    // success
-
-            q->setErrorString(QProcess::tr("Could not open input redirection for reading"));
+            setErrorAndEmit(QProcess::FailedToStart,
+                            QProcess::tr("Could not open input redirection for reading"));
         } else {
             int mode = O_WRONLY | O_CREAT;
             if (channel.append)
@@ -216,12 +216,9 @@ bool QProcessPrivate::openChannel(Channel &channel)
             if ( (channel.pipe[1] = qt_safe_open(fname, mode, 0666)) != -1)
                 return true; // success
 
-            q->setErrorString(QProcess::tr("Could not open output redirection for writing"));
+            setErrorAndEmit(QProcess::FailedToStart,
+                            QProcess::tr("Could not open input redirection for reading"));
         }
-
-        // could not open file
-        processError = QProcess::FailedToStart;
-        emit q->error(processError);
         cleanup();
         return false;
     } else {
@@ -330,9 +327,7 @@ void QProcessPrivate::startProcess()
         !openChannel(stdoutChannel) ||
         !openChannel(stderrChannel) ||
         qt_create_pipe(childStartedPipe) != 0) {
-        processError = QProcess::FailedToStart;
-        q->setErrorString(qt_error_string(errno));
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::FailedToStart, qt_error_string(errno));
         cleanup();
         return;
     }
@@ -458,9 +453,8 @@ void QProcessPrivate::startProcess()
         qDebug("fork failed: %s", qPrintable(qt_error_string(lastForkErrno)));
 #endif
         q->setProcessState(QProcess::NotRunning);
-        processError = QProcess::FailedToStart;
-        q->setErrorString(QProcess::tr("Resource error (fork failure): %1").arg(qt_error_string(lastForkErrno)));
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::FailedToStart,
+                        QProcess::tr("Resource error (fork failure): %1").arg(qt_error_string(lastForkErrno)));
         cleanup();
         return;
     }
@@ -808,8 +802,6 @@ void QProcessPrivate::killProcess()
 
 bool QProcessPrivate::waitForStarted(int msecs)
 {
-    Q_Q(QProcess);
-
 #if defined (QPROCESS_DEBUG)
     qDebug("QProcessPrivate::waitForStarted(%d) waiting for child to start (fd = %d)", msecs,
            childStartedPipe[0]);
@@ -819,8 +811,7 @@ bool QProcessPrivate::waitForStarted(int msecs)
     FD_ZERO(&fds);
     FD_SET(childStartedPipe[0], &fds);
     if (qt_select_msecs(childStartedPipe[0] + 1, &fds, 0, msecs) == 0) {
-        processError = QProcess::Timedout;
-        q->setErrorString(QProcess::tr("Process operation timed out"));
+        setError(QProcess::Timedout);
 #if defined (QPROCESS_DEBUG)
         qDebug("QProcessPrivate::waitForStarted(%d) == false (timed out)", msecs);
 #endif
@@ -847,7 +838,6 @@ QList<QSocketNotifier *> QProcessPrivate::defaultNotifiers() const
 
 bool QProcessPrivate::waitForReadyRead(int msecs)
 {
-    Q_Q(QProcess);
 #if defined (QPROCESS_DEBUG)
     qDebug("QProcessPrivate::waitForReadyRead(%d)", msecs);
 #endif
@@ -890,8 +880,7 @@ bool QProcessPrivate::waitForReadyRead(int msecs)
             break;
         }
         if (ret == 0) {
-            processError = QProcess::Timedout;
-            q->setErrorString(QProcess::tr("Process operation timed out"));
+            setError(QProcess::Timedout);
             return false;
         }
 
@@ -927,7 +916,6 @@ bool QProcessPrivate::waitForReadyRead(int msecs)
 
 bool QProcessPrivate::waitForBytesWritten(int msecs)
 {
-    Q_Q(QProcess);
 #if defined (QPROCESS_DEBUG)
     qDebug("QProcessPrivate::waitForBytesWritten(%d)", msecs);
 #endif
@@ -972,8 +960,7 @@ bool QProcessPrivate::waitForBytesWritten(int msecs)
         }
 
         if (ret == 0) {
-            processError = QProcess::Timedout;
-            q->setErrorString(QProcess::tr("Process operation timed out"));
+            setError(QProcess::Timedout);
             return false;
         }
 
@@ -1002,7 +989,6 @@ bool QProcessPrivate::waitForBytesWritten(int msecs)
 
 bool QProcessPrivate::waitForFinished(int msecs)
 {
-    Q_Q(QProcess);
 #if defined (QPROCESS_DEBUG)
     qDebug("QProcessPrivate::waitForFinished(%d)", msecs);
 #endif
@@ -1046,8 +1032,7 @@ bool QProcessPrivate::waitForFinished(int msecs)
             break;
         }
         if (ret == 0) {
-            processError = QProcess::Timedout;
-            q->setErrorString(QProcess::tr("Process operation timed out"));
+            setError(QProcess::Timedout);
             return false;
         }
 
diff --git a/src/corelib/io/qprocess_win.cpp b/src/corelib/io/qprocess_win.cpp
index 8bbca20365..5c9db05eff 100644
--- a/src/corelib/io/qprocess_win.cpp
+++ b/src/corelib/io/qprocess_win.cpp
@@ -217,7 +217,8 @@ bool QProcessPrivate::openChannel(Channel &channel)
             if (channel.pipe[0] != INVALID_Q_PIPE)
                 return true;
 
-            q->setErrorString(QProcess::tr("Could not open input redirection for reading"));
+            setErrorAndEmit(QProcess::FailedToStart,
+                            QProcess::tr("Could not open input redirection for reading"));
         } else {
             // open in write mode
             channel.pipe[0] = INVALID_Q_PIPE;
@@ -237,12 +238,9 @@ bool QProcessPrivate::openChannel(Channel &channel)
                 return true;
             }
 
-            q->setErrorString(QProcess::tr("Could not open output redirection for writing"));
+            setErrorAndEmit(QProcess::FailedToStart,
+                            QProcess::tr("Could not open output redirection for writing"));
         }
-
-        // could not open file
-        processError = QProcess::FailedToStart;
-        emit q->error(processError);
         cleanup();
         return false;
     } else {
@@ -504,9 +502,10 @@ void QProcessPrivate::startProcess()
                             environment.isEmpty() ? 0 : envlist.data(),
                             workingDirectory.isEmpty() ? 0 : (wchar_t*)QDir::toNativeSeparators(workingDirectory).utf16(),
                             &startupInfo, pid);
+    QString errorString;
     if (!success) {
         // Capture the error string before we do CloseHandle below
-        q->setErrorString(QProcess::tr("Process failed to start: %1").arg(qt_error_string()));
+        errorString = QProcess::tr("Process failed to start: %1").arg(qt_error_string());
     }
 
     if (stdinChannel.pipe[0] != INVALID_Q_PIPE) {
@@ -524,8 +523,7 @@ void QProcessPrivate::startProcess()
 
     if (!success) {
         cleanup();
-        processError = QProcess::FailedToStart;
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::FailedToStart, errorString);
         q->setProcessState(QProcess::NotRunning);
         return;
     }
@@ -595,16 +593,13 @@ void QProcessPrivate::killProcess()
 
 bool QProcessPrivate::waitForStarted(int)
 {
-    Q_Q(QProcess);
-
     if (processStarted())
         return true;
 
     if (processError == QProcess::FailedToStart)
         return false;
 
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }
 
@@ -636,8 +631,6 @@ bool QProcessPrivate::drainOutputPipes()
 
 bool QProcessPrivate::waitForReadyRead(int msecs)
 {
-    Q_Q(QProcess);
-
     QIncrementalSleepTimer timer(msecs);
 
     forever {
@@ -663,15 +656,12 @@ bool QProcessPrivate::waitForReadyRead(int msecs)
             break;
     }
 
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }
 
 bool QProcessPrivate::waitForBytesWritten(int msecs)
 {
-    Q_Q(QProcess);
-
     QIncrementalSleepTimer timer(msecs);
 
     forever {
@@ -731,14 +721,12 @@ bool QProcessPrivate::waitForBytesWritten(int msecs)
             break;
     }
 
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }
 
 bool QProcessPrivate::waitForFinished(int msecs)
 {
-    Q_Q(QProcess);
 #if defined QPROCESS_DEBUG
     qDebug("QProcessPrivate::waitForFinished(%d)", msecs);
 #endif
@@ -770,8 +758,7 @@ bool QProcessPrivate::waitForFinished(int msecs)
             break;
     }
 
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }
 
@@ -814,13 +801,10 @@ qint64 QProcessPrivate::writeToStdin(const char *data, qint64 maxlen)
 
 bool QProcessPrivate::waitForWrite(int msecs)
 {
-    Q_Q(QProcess);
-
     if (!stdinChannel.writer || stdinChannel.writer->waitForWrite(msecs))
         return true;
 
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }
 
diff --git a/src/corelib/io/qprocess_wince.cpp b/src/corelib/io/qprocess_wince.cpp
index 53767758c2..807472b7b2 100644
--- a/src/corelib/io/qprocess_wince.cpp
+++ b/src/corelib/io/qprocess_wince.cpp
@@ -138,8 +138,7 @@ void QProcessPrivate::startProcess()
 
     if (!success) {
         cleanup();
-        processError = QProcess::FailedToStart;
-        emit q->error(processError);
+        setErrorAndEmit(QProcess::FailedToStart);
         q->setProcessState(QProcess::NotRunning);
         return;
     }
@@ -210,8 +209,7 @@ bool QProcessPrivate::waitForStarted(int)
     if (processError == QProcess::FailedToStart)
         return false;
 
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }
 
@@ -251,8 +249,7 @@ bool QProcessPrivate::waitForFinished(int msecs)
         if (timer.hasTimedOut())
             break;
     }
-    processError = QProcess::Timedout;
-    q->setErrorString(QProcess::tr("Process operation timed out"));
+    setError(QProcess::Timedout);
     return false;
 }