Implement a debugger for Icinga scripts

fixes #10547

icinga-app/icinga.cpp

@@ -193,9 +193,9 @@ int Main(void)
 		("app,a", po::value<std::string>(), "application library name (default: icinga)")
 		("library,l", po::value<std::vector<std::string> >(), "load a library")
 		("include,I", po::value<std::vector<std::string> >(), "add include search directory")
-		("log-level,x", po::value<std::string>()
+		("log-level,x", po::value<std::string>(), "specify the log level for the console log.\n"
-			, "specify the log level for the console log.\n"
+		    "The valid value is either debug, notice, information (default), warning, or critical")
-			"The valid value is either debug, notice, information (default), warning, or critical");
+		("script-debugger,X", "whether to enable the script debugger");
 
 	po::options_description hiddenDesc("Hidden options");
 
@@ -264,6 +264,9 @@ int Main(void)
 		}
 	}
 
+	if (vm.count("script-debugger"))
+		Application::SetScriptDebuggerEnabled(true);
+
 	Application::DeclareStatePath(Application::GetLocalStateDir() + "/lib/icinga2/icinga2.state");
 	Application::DeclareModAttrPath(Application::GetLocalStateDir() + "/lib/icinga2/modified-attributes.conf");
 	Application::DeclareObjectsPath(Application::GetLocalStateDir() + "/cache/icinga2/icinga2.debug");

lib/base/application.cpp

@@ -63,6 +63,7 @@ static bool l_InExceptionHandler = false;
 int Application::m_ArgC;
 char **Application::m_ArgV;
 double Application::m_StartTime;
+bool Application::m_ScriptDebuggerEnabled = false;
 
 /**
  * Constructor for the Application class.
@@ -1450,6 +1451,16 @@ void Application::SetStartTime(double ts)
 	m_StartTime = ts;
 }
 
+bool Application::GetScriptDebuggerEnabled(void)
+{
+	return m_ScriptDebuggerEnabled;
+}
+
+void Application::SetScriptDebuggerEnabled(bool enabled)
+{
+	m_ScriptDebuggerEnabled = enabled;
+}
+
 void Application::ValidateName(const String& value, const ValidationUtils& utils)
 {
 	ObjectImpl<Application>::ValidateName(value, utils);

lib/base/application.hpp

@@ -134,6 +134,9 @@ public:
 	static double GetStartTime(void);
 	static void SetStartTime(double ts);
 
+	static bool GetScriptDebuggerEnabled(void);
+	static void SetScriptDebuggerEnabled(bool enabled);
+
 	static void DisplayInfoMessage(std::ostream& os, bool skipVersion = false);
 
 protected:
@@ -164,6 +167,7 @@ private:
 	static bool m_Debugging; /**< Whether debugging is enabled. */
 	static LogSeverity m_DebuggingSeverity; /**< Whether debugging severity is set. */
 	static double m_StartTime;
+	static bool m_ScriptDebuggerEnabled;
 
 #ifndef _WIN32
 	static void SigIntTermHandler(int signum);

lib/base/exception.cpp

@@ -254,7 +254,7 @@ ScriptError::ScriptError(const String& message)
 { }
 
 ScriptError::ScriptError(const String& message, const DebugInfo& di, bool incompleteExpr)
-	: m_Message(message), m_DebugInfo(di), m_IncompleteExpr(incompleteExpr)
+	: m_Message(message), m_DebugInfo(di), m_IncompleteExpr(incompleteExpr), m_HandledByDebugger(false)
 { }
 
 ScriptError::~ScriptError(void) throw()
@@ -275,6 +275,16 @@ bool ScriptError::IsIncompleteExpression(void) const
 	return m_IncompleteExpr;;
 }
 
+bool ScriptError::IsHandledByDebugger(void) const
+{
+	return m_HandledByDebugger;
+}
+
+void ScriptError::SetHandledByDebugger(bool handled)
+{
+	m_HandledByDebugger = handled;
+}
+
 posix_error::posix_error(void)
 	: m_Message(NULL)
 { }

lib/base/exception.hpp

@@ -60,10 +60,14 @@ public:
 	DebugInfo GetDebugInfo(void) const;
 	bool IsIncompleteExpression(void) const;
 
+	bool IsHandledByDebugger(void) const;
+	void SetHandledByDebugger(bool handled);
+
 private:
 	String m_Message;
 	DebugInfo m_DebugInfo;
 	bool m_IncompleteExpr;
+	bool m_HandledByDebugger;
 };
 
 /*

lib/cli/consolecommand.cpp

@@ -46,6 +46,36 @@ static String l_Session;
 
 REGISTER_CLICOMMAND("console", ConsoleCommand);
 
+INITIALIZE_ONCE(&ConsoleCommand::StaticInitialize);
+
+void ConsoleCommand::BreakpointHandler(ScriptFrame& frame, ScriptError *ex, const DebugInfo& di)
+{
+	static boost::mutex mutex;
+	boost::mutex::scoped_lock lock(mutex);
+
+	if (!Application::GetScriptDebuggerEnabled())
+		return;
+
+	if (ex && ex->IsHandledByDebugger())
+		return;
+
+	std::cout << "Breakpoint encountered in '" << di.Path << "' at " << di << "\n";
+
+	if (ex) {
+		std::cout << "Exception: " << DiagnosticInformation(*ex);
+		ex->SetHandledByDebugger(true);
+	}
+
+	std::cout << "You can leave the debugger and continue the program with \"$quit\".\n";
+
+	ConsoleCommand::RunScriptConsole(frame);
+}
+
+void ConsoleCommand::StaticInitialize(void)
+{
+	Expression::OnBreakpoint.connect(&ConsoleCommand::BreakpointHandler);
+}
+
 String ConsoleCommand::GetDescription(void) const
 {
 	return "Interprets Icinga script expressions.";
@@ -118,19 +148,15 @@ char *ConsoleCommand::ConsoleCompleteHelper(const char *word, int state)
  */
 int ConsoleCommand::Run(const po::variables_map& vm, const std::vector<std::string>& ap) const
 {
-	std::map<String, String> lines;
-	int next_line = 1;
-
 #ifdef HAVE_EDITLINE
 	rl_completion_entry_function = ConsoleCommand::ConsoleCompleteHelper;
 	rl_completion_append_character = '\0';
 #endif /* HAVE_EDITLINE */
 
-	String addr;
+	String addr, session;
 	ScriptFrame scriptFrame;
 
-	l_ScriptFrame = &scriptFrame;
+	session = Utility::NewUniqueID();
-	l_Session = Utility::NewUniqueID();
 
 	if (vm.count("sandbox"))
 		scriptFrame.Sandboxed = true;
@@ -144,9 +170,24 @@ int ConsoleCommand::Run(const po::variables_map& vm, const std::vector<std::stri
 	if (addrEnv)
 		addr = addrEnv;
 
-	if (vm.count("connect")) {
+	if (vm.count("connect"))
 		addr = vm["connect"].as<std::string>();
-	}
+
+	String command;
+
+	if (vm.count("eval"))
+		command = vm["eval"].as<std::string>();
+
+	return RunScriptConsole(scriptFrame, addr, session, command);;
+}
+
+int ConsoleCommand::RunScriptConsole(ScriptFrame& scriptFrame, const String& addr, const String& session, const String& commandOnce)
+{
+	std::map<String, String> lines;
+	int next_line = 1;
+
+	l_ScriptFrame = &scriptFrame;
+	l_Session = session;
 
 	if (!addr.IsEmpty()) {
 		Url::Ptr url;
@@ -182,7 +223,7 @@ int ConsoleCommand::Run(const po::variables_map& vm, const std::vector<std::stri
 incomplete:
 		std::string line;
 
-		if (!vm.count("eval")) {
+		if (commandOnce.IsEmpty()) {
 #ifdef HAVE_EDITLINE
 			std::ostringstream promptbuf;
 			std::ostream& os = promptbuf;
@@ -215,7 +256,14 @@ incomplete:
 			std::getline(std::cin, line);
 #endif /* HAVE_EDITLINE */
 		} else
-			line = vm["eval"].as<std::string>();
+			line = commandOnce;
+
+		if (!line.empty() && line[0] == '$') {
+			if (line == "$quit")
+				break;
+
+			std::cout << "Unknown debugger command: " << line;
+		}
 
 		if (!command.empty())
 			command += "\n";
@@ -254,7 +302,7 @@ incomplete:
 					boost::rethrow_exception(eptr);
 			}
 
-			if (!vm.count("eval")) {
+			if (commandOnce.IsEmpty()) {
 				std::cout << ConsoleColorTag(Console_ForegroundCyan);
 				ConfigWriter::EmitValue(std::cout, 1, result);
 				std::cout << ConsoleColorTag(Console_Normal) << "\n";
@@ -308,12 +356,12 @@ incomplete:
 
 			std::cout << ex.what() << "\n";
 
-			if (vm.count("eval"))
+			if (!commandOnce.IsEmpty())
 				return EXIT_FAILURE;
 		} catch (const std::exception& ex) {
 			std::cout << "Error: " << DiagnosticInformation(ex) << "\n";
 
-			if (vm.count("eval"))
+			if (!commandOnce.IsEmpty())
 				return EXIT_FAILURE;
 		}
 

lib/cli/consolecommand.hpp

@@ -22,6 +22,7 @@
 
 #include "cli/clicommand.hpp"
 #include "base/exception.hpp"
+#include "base/scriptframe.hpp"
 
 namespace icinga
 {
@@ -36,6 +37,8 @@ class ConsoleCommand : public CLICommand
 public:
 	DECLARE_PTR_TYPEDEFS(ConsoleCommand);
 
+	static void StaticInitialize(void);
+
 	virtual String GetDescription(void) const override;
 	virtual String GetShortDescription(void) const override;
 	virtual ImpersonationLevel GetImpersonationLevel(void) const override;
@@ -43,6 +46,9 @@ public:
 	    boost::program_options::options_description& hiddenDesc) const override;
 	virtual int Run(const boost::program_options::variables_map& vm, const std::vector<std::string>& ap) const override;
 
+	static int RunScriptConsole(ScriptFrame& scriptFrame, const String& addr = String(),
+	    const String& session = String(), const String& commandOnce = String());
+
 private:
 	mutable boost::mutex m_Mutex;
 	mutable boost::condition_variable m_CV;
@@ -58,6 +64,8 @@ private:
 	static char *ConsoleCompleteHelper(const char *word, int state);
 #endif /* HAVE_EDITLINE */
 
+	static void BreakpointHandler(ScriptFrame& frame, ScriptError *ex, const DebugInfo& di);
+
 };
 
 }

lib/config/config_lexer.ll

@@ -198,6 +198,7 @@ throw				return T_THROW;
 ignore_on_error			return T_IGNORE_ON_ERROR;
 current_filename		return T_CURRENT_FILENAME;
 current_line			return T_CURRENT_LINE;
+debugger			return T_DEBUGGER;
 =\>				return T_FOLLOWS;
 \<\<				return T_SHIFT_LEFT;
 \>\>				return T_SHIFT_RIGHT;

lib/config/config_parser.yy

@@ -146,6 +146,7 @@ static void MakeRBinaryOp(Expression** result, Expression *left, Expression *rig
 %token T_IGNORE_ON_ERROR "ignore_on_error (T_IGNORE_ON_ERROR)"
 %token T_CURRENT_FILENAME "current_filename (T_CURRENT_FILENAME)"
 %token T_CURRENT_LINE "current_line (T_CURRENT_LINE)"
+%token T_DEBUGGER "debugger (T_DEBUGGER)"
 %token T_USE "use (T_USE)"
 %token T_OBJECT "object (T_OBJECT)"
 %token T_TEMPLATE "template (T_TEMPLATE)"
@@ -514,6 +515,10 @@ lterm: T_LIBRARY rterm
 	{
 		$$ = new ContinueExpression(@$);
 	}
+	| T_DEBUGGER
+	{
+		$$ = new BreakpointExpression(@$);
+	}
 	| apply
 	| object
 	| T_FOR '(' identifier T_FOLLOWS identifier T_IN rterm ')' rterm_scope_require_side_effect

lib/config/expression.cpp

@@ -34,9 +34,23 @@
 
 using namespace icinga;
 
+boost::signals2::signal<void (ScriptFrame&, ScriptError *ex, const DebugInfo&)> Expression::OnBreakpoint;
+boost::thread_specific_ptr<bool> l_InBreakpointHandler;
+
 Expression::~Expression(void)
 { }
 
+void Expression::ScriptBreakpoint(ScriptFrame& frame, ScriptError *ex, const DebugInfo& di)
+{
+	bool *inHandler = l_InBreakpointHandler.get();
+	if (!inHandler || !*inHandler) {
+		inHandler = new bool(true);
+		l_InBreakpointHandler.reset(inHandler);
+		OnBreakpoint(frame, ex, di);
+		*inHandler = false;
+	}
+}
+
 ExpressionResult Expression::Evaluate(ScriptFrame& frame, DebugHint *dhint) const
 {
 	try {
@@ -48,7 +62,8 @@ ExpressionResult Expression::Evaluate(ScriptFrame& frame, DebugHint *dhint) cons
 #endif /* I2_DEBUG */
 
 		return DoEvaluate(frame, dhint);
-	} catch (const ScriptError& ex) {
+	} catch (ScriptError& ex) {
+		ScriptBreakpoint(frame, &ex, GetDebugInfo());
 		throw;
 	} catch (const std::exception& ex) {
 		BOOST_THROW_EXCEPTION(ScriptError("Error while evaluating expression: " + String(ex.what()), GetDebugInfo())
@@ -859,3 +874,11 @@ ExpressionResult IncludeExpression::DoEvaluate(ScriptFrame& frame, DebugHint *dh
 
 	return res;
 }
+
+ExpressionResult BreakpointExpression::DoEvaluate(ScriptFrame& frame, DebugHint *dhint) const
+{
+	ScriptBreakpoint(frame, NULL, GetDebugInfo());
+
+	return Empty;
+}
+

lib/config/expression.hpp

@@ -198,6 +198,10 @@ public:
 	virtual const DebugInfo& GetDebugInfo(void) const;
 
 	virtual ExpressionResult DoEvaluate(ScriptFrame& frame, DebugHint *dhint) const = 0;
+
+	static boost::signals2::signal<void (ScriptFrame& frame, ScriptError *ex, const DebugInfo& di)> OnBreakpoint;
+
+	static void ScriptBreakpoint(ScriptFrame& frame, ScriptError *ex, const DebugInfo& di);
 };
 
 I2_CONFIG_API Expression *MakeIndexer(ScopeSpecifier scopeSpec, const String& index);
@@ -937,6 +941,17 @@ private:
 	String m_Package;
 };
 
+class I2_CONFIG_API BreakpointExpression : public DebuggableExpression
+{
+public:
+	BreakpointExpression(const DebugInfo& debugInfo = DebugInfo())
+	    : DebuggableExpression(debugInfo)
+	{ }
+
+protected:
+	virtual ExpressionResult DoEvaluate(ScriptFrame& frame, DebugHint *dhint) const override;
+};
+
 }
 
 #endif /* EXPRESSION_H */