Debugger: Provide a startup customization hook for 3rd party plugins

Change-Id: Ia587abcb1bdcdfbf192d3314610ec9addf370c9b
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/debugger/debuggerengine.cpp

@@ -1380,6 +1380,12 @@ QString DebuggerEngine::expand(const QString &string) const
     return d->m_runParameters.macroExpander->expand(string);
 }
 
+QString DebuggerEngine::nativeStartupCommands() const
+{
+    return expand(QStringList({stringSetting(GdbStartupCommands),
+                               runParameters().additionalStartupCommands}).join('\n'));
+}
+
 void DebuggerEngine::updateBreakpointMarker(const Breakpoint &bp)
 {
     d->m_disassemblerAgent.updateBreakpointMarker(bp);

src/plugins/debugger/debuggerengine.h

@@ -329,6 +329,7 @@ public:
     void removeBreakpointMarker(const Breakpoint &bp);
 
     QString expand(const QString &string) const;
+    QString nativeStartupCommands() const;
 
 signals:
     void stateChanged(Debugger::DebuggerState state);

src/plugins/debugger/debuggerstartparameters.h

@@ -114,6 +114,9 @@ public:
 
     // Used by general core file debugging. Public access requested in QTCREATORBUG-17158.
     QString coreFile;
+
+    // Macro-expanded and passed to debugger startup.
+    QString additionalStartupCommands;
 };
 
 } // namespace Debugger

src/plugins/debugger/gdb/gdbengine.cpp

@@ -4079,7 +4079,7 @@ void GdbEngine::loadInitScript()
               ).arg(script));
         }
     } else {
-        const QString commands = expand(stringSetting(GdbStartupCommands));
+        const QString commands = nativeStartupCommands();
         if (!commands.isEmpty())
             runCommand({commands});
     }

src/plugins/debugger/lldb/lldbengine.cpp

@@ -307,7 +307,7 @@ void LldbEngine::startLldbStage2()
     m_lldbProc.write("script print(dir())\n");
     m_lldbProc.write("script theDumper = Dumper()\n"); // This triggers reportState("enginesetupok")
 
-    const QString commands = expand(stringSetting(GdbStartupCommands));
+    const QString commands = nativeStartupCommands();
     if (!commands.isEmpty())
         m_lldbProc.write(commands.toLocal8Bit() + '\n');
 }