Valgrind: Do not start valgrind if it does not exist

...and print a warning with some user hint inside the application
output instead.
Drive-by fix: silence a soft assert in case of a failed start of
callgrind.

Fixes: QTCREATORBUG-28988
Change-Id: I4fd0253e1f18489031e2f6cfa276c4df5ea4483a
Reviewed-by: hjk <hjk@qt.io>

src/plugins/valgrind/callgrindengine.cpp

@@ -258,7 +258,8 @@ void CallgrindToolRunner::triggerParse()
     }
 
     const auto afterCopy = [this](expected_str<void> res) {
-        QTC_ASSERT_EXPECTED(res, return);
+        if (!res) // failed to run callgrind
+            return;
         showStatusMessage(Tr::tr("Parsing Profile Data..."));
         m_parser.parse(m_hostOutputFile);
     };

src/plugins/valgrind/memchecktool.cpp

@@ -7,7 +7,6 @@
 #include "valgrindengine.h"
 #include "valgrindrunner.h"
 #include "valgrindsettings.h"
-#include "valgrindsettings.h"
 #include "valgrindtr.h"
 
 #include "xmlprotocol/error.h"

src/plugins/valgrind/valgrindengine.cpp

@@ -22,8 +22,6 @@
 
 #include <QApplication>
 
-#define VALGRIND_DEBUG_OUTPUT 0
-
 using namespace Debugger;
 using namespace Core;
 using namespace Utils;
@@ -55,6 +53,16 @@ ValgrindToolRunner::ValgrindToolRunner(RunControl *runControl)
 
 void ValgrindToolRunner::start()
 {
+    FilePath valgrindExecutable = m_settings.valgrindExecutable.filePath();
+    if (IDevice::ConstPtr dev = DeviceKitAspect::device(runControl()->kit()))
+        valgrindExecutable = dev->filePath(valgrindExecutable.path());
+    if (!valgrindExecutable.isExecutableFile()) {
+        reportFailure(Tr::tr("Valgrind executable \"%1\" not found or not executable.\n"
+                             "Check settings or ensure valgrind is installed and available in PATH.")
+                      .arg(valgrindExecutable.toUserOutput()));
+        return;
+    }
+
     FutureProgress *fp = ProgressManager::addTimedTask(m_progress, progressTitle(), "valgrind", 100);
     connect(fp, &FutureProgress::canceled,
             this, &ValgrindToolRunner::handleProgressCanceled);
@@ -62,17 +70,6 @@ void ValgrindToolRunner::start()
             this, &ValgrindToolRunner::handleProgressFinished);
     m_progress.reportStarted();
 
-#if VALGRIND_DEBUG_OUTPUT
-    emit outputReceived(Tr::tr("Valgrind options: %1").arg(toolArguments().join(' ')), LogMessageFormat);
-    emit outputReceived(Tr::tr("Working directory: %1").arg(runnable().workingDirectory), LogMessageFormat);
-    emit outputReceived(Tr::tr("Command line arguments: %1").arg(runnable().debuggeeArgs), LogMessageFormat);
-#endif
-
-
-    FilePath valgrindExecutable = m_settings.valgrindExecutable.filePath();
-    if (IDevice::ConstPtr dev = DeviceKitAspect::device(runControl()->kit()))
-        valgrindExecutable = dev->filePath(valgrindExecutable.path());
-
     CommandLine valgrind{valgrindExecutable};
     valgrind.addArgs(m_settings.valgrindArguments.value(), CommandLine::Raw);
     valgrind.addArgs(genericToolArguments());