Debugger: Show output of debugger detection

... in tooltip of debugger path lineedit.

Helps with cases where necessary libraries are missing.

The tooltip is a bit hard to recognize, but as such cases now also
are marked in red text there's at least some direct hint that something
is not ok.

Change-Id: Ic5da8dcb1921a98f91f6eed755fa87ce5feed698
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/debugger/debuggeritem.cpp

@@ -151,7 +151,7 @@ static bool isUVisionExecutable(const QFileInfo &fileInfo)
     return baseName == "UV4";
 }
 
-void DebuggerItem::reinitializeFromFile(const Environment &sysEnv)
+void DebuggerItem::reinitializeFromFile(const Environment &sysEnv, QString *error)
 {
     // CDB only understands the single-dash -version, whereas GDB and LLDB are
     // happy with both -version and --version. So use the "working" -version
@@ -190,12 +190,14 @@ void DebuggerItem::reinitializeFromFile(const Environment &sysEnv)
     proc.setEnvironment(sysEnv);
     proc.setCommand({m_command, {version}});
     proc.runBlocking();
+    const QString output = proc.allOutput().trimmed();
     if (proc.result() != QtcProcess::FinishedWithSuccess) {
+        if (error)
+            *error = output;
         m_engineType = NoEngineType;
         return;
     }
     m_abis.clear();
-    const QString output = proc.allOutput().trimmed();
     if (output.contains("gdb")) {
         m_engineType = GdbEngineType;
 
@@ -263,6 +265,8 @@ void DebuggerItem::reinitializeFromFile(const Environment &sysEnv)
         m_engineType = PdbEngineType;
         return;
     }
+    if (error)
+        *error = output;
     m_engineType = NoEngineType;
 }
 

src/plugins/debugger/debuggeritem.h

@@ -98,7 +98,8 @@ public:
     bool operator==(const DebuggerItem &other) const;
     bool operator!=(const DebuggerItem &other) const { return !operator==(other); }
 
-    void reinitializeFromFile(const Utils::Environment &sysEnv = Utils::Environment::systemEnvironment());
+    void reinitializeFromFile(const Utils::Environment &sysEnv = Utils::Environment::systemEnvironment(),
+                              QString *error = nullptr);
 
     Utils::FilePath workingDirectory() const { return m_workingDirectory; }
     void setWorkingDirectory(const Utils::FilePath &workingPath) { m_workingDirectory = workingPath; }

src/plugins/debugger/debuggeritemmanager.cpp

@@ -314,6 +314,15 @@ DebuggerItemConfigWidget::DebuggerItemConfigWidget()
     m_binaryChooser->setExpectedKind(PathChooser::ExistingCommand);
     m_binaryChooser->setMinimumWidth(400);
     m_binaryChooser->setHistoryCompleter("DebuggerPaths");
+    m_binaryChooser->setValidationFunction([this](FancyLineEdit *edit, QString *errorMessage) {
+        if (!m_binaryChooser->defaultValidationFunction()(edit, errorMessage))
+            return false;
+        DebuggerItem item;
+        item.setCommand(m_binaryChooser->filePath());
+        errorMessage->clear();
+        item.reinitializeFromFile({}, errorMessage);
+        return errorMessage->isEmpty();
+    });
 
     m_workingDirectoryChooser = new PathChooser(this);
     m_workingDirectoryChooser->setExpectedKind(PathChooser::Directory);