(svn r15467) -Fix [NoAI]: AIs with an error in their info.nut are no longer available in-game.

7 files changed, 108 insertions, 30 deletions

diff --git a/src/ai/ai_info.cpp b/src/ai/ai_info.cpp
index de1a71bc9..d55c6e57c 100644
--- a/src/ai/ai_info.cpp
+++ b/src/ai/ai_info.cpp
@@ -45,9 +45,9 @@ AILibrary::~AILibrary()
 	free((void *)this->category);
 }
 
-void AIFileInfo::GetSettings() const
+bool AIFileInfo::GetSettings()
 {
-	this->engine->CallMethod(*this->SQ_instance, "GetSettings", NULL, -1);
+	return this->engine->CallMethod(*this->SQ_instance, "GetSettings", NULL, -1);
 }
 
 bool AIFileInfo::CheckMethod(const char *name) const
@@ -90,13 +90,13 @@ bool AIFileInfo::CheckMethod(const char *name) const
 	info->main_script = strdup(info->base->GetMainScript());
 
 	/* Cache the data the info file gives us. */
-	info->author = info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetAuthor");
-	info->name = info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetName");
-	info->short_name = info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetShortName");
-	info->description = info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetDescription");
-	info->date = info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetDate");
-	info->version = info->engine->CallIntegerMethod(*info->SQ_instance, "GetVersion");
-	info->instance_name = info->engine->CallStringMethodStrdup(*info->SQ_instance, "CreateInstance");
+	if (!info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetAuthor", &info->author)) return SQ_ERROR;
+	if (!info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetName", &info->name)) return SQ_ERROR;
+	if (!info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetShortName", &info->short_name)) return SQ_ERROR;
+	if (!info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetDescription", &info->description)) return SQ_ERROR;
+	if (!info->engine->CallStringMethodStrdup(*info->SQ_instance, "GetDate", &info->date)) return SQ_ERROR;
+	if (!info->engine->CallIntegerMethod(*info->SQ_instance, "GetVersion", &info->version)) return SQ_ERROR;
+	if (!info->engine->CallStringMethodStrdup(*info->SQ_instance, "CreateInstance", &info->instance_name)) return SQ_ERROR;
 
 	return 0;
 }
@@ -118,10 +118,10 @@ bool AIFileInfo::CheckMethod(const char *name) const
 
 	/* Check if we have settings */
 	if (info->engine->MethodExists(*info->SQ_instance, "GetSettings")) {
-		info->GetSettings();
+		if (!info->GetSettings()) return SQ_ERROR;
 	}
 	if (info->engine->MethodExists(*info->SQ_instance, "MinVersionToLoad")) {
-		info->min_loadable_version = info->engine->CallIntegerMethod(*info->SQ_instance, "MinVersionToLoad");
+		if (!info->engine->CallIntegerMethod(*info->SQ_instance, "MinVersionToLoad", &info->min_loadable_version)) return SQ_ERROR;
 	} else {
 		info->min_loadable_version = info->GetVersion();
 	}
@@ -367,7 +367,10 @@ int AIInfo::GetSettingDefaultValue(const char *name) const
 	}
 
 	/* Cache the category */
-	library->category = library->engine->CallStringMethodStrdup(*library->SQ_instance, "GetCategory");
+	if (!library->engine->CallStringMethodStrdup(*library->SQ_instance, "GetCategory", &library->category)) {
+		delete library;
+		return SQ_ERROR;
+	}
 
 	/* Register the Library to the base system */
 	library->base->RegisterLibrary(library);
diff --git a/src/ai/ai_info.hpp b/src/ai/ai_info.hpp
index b43474500..ef8505e2d 100644
--- a/src/ai/ai_info.hpp
+++ b/src/ai/ai_info.hpp
@@ -72,7 +72,7 @@ public:
 	/**
 	 * Get the settings of the AI.
 	 */
-	void GetSettings() const;
+	bool GetSettings();
 
 	/**
 	 * Get the date of the AI.
diff --git a/src/ai/ai_instance.cpp b/src/ai/ai_instance.cpp
index 496ad6c34..12165e9dd 100644
--- a/src/ai/ai_instance.cpp
+++ b/src/ai/ai_instance.cpp
@@ -249,6 +249,11 @@ void AIInstance::Died()
 void AIInstance::GameLoop()
 {
 	if (this->is_dead) return;
+	if (this->engine->HasScriptCrashed()) {
+		/* The script crashed during saving, kill it here. */
+		this->Died();
+		return;
+	}
 	this->controller->ticks++;
 
 	if (this->suspend   < -1) this->suspend++; // Multiplayer suspend, increase up to -1.
@@ -275,12 +280,12 @@ void AIInstance::GameLoop()
 			AIObject::SetAllowDoCommand(false);
 			/* Run the constructor if it exists. Don't allow any DoCommands in it. */
 			if (this->engine->MethodExists(*this->instance, "constructor")) {
-				this->engine->CallMethod(*this->instance, "constructor");
+				if (!this->engine->CallMethod(*this->instance, "constructor")) { this->Died(); return; }
 			}
-			this->CallLoad();
+			if (!this->CallLoad()) { this->Died(); return; }
 			AIObject::SetAllowDoCommand(true);
 			/* Start the AI by calling Start() */
-			if (!this->engine->CallMethod(*this->instance, "Start",  _settings_game.ai.ai_max_opcode_till_suspend)) this->Died();
+			if (!this->engine->CallMethod(*this->instance, "Start",  _settings_game.ai.ai_max_opcode_till_suspend) || !this->engine->IsSuspended()) this->Died();
 		} catch (AI_VMSuspend e) {
 			this->suspend  = e.GetSuspendTime();
 			this->callback = e.GetSuspendCallback();
@@ -500,8 +505,8 @@ enum {
 
 void AIInstance::Save()
 {
-	/* Don't save data if the AI didn't start yet. */
-	if (this->engine == NULL) {
+	/* Don't save data if the AI didn't start yet or if it crashed. */
+	if (this->engine == NULL || this->engine->HasScriptCrashed()) {
 		SaveEmpty();
 		return;
 	}
@@ -526,7 +531,12 @@ void AIInstance::Save()
 		/* We don't want to be interrupted during the save function. */
 		bool backup_allow = AIObject::GetAllowDoCommand();
 		AIObject::SetAllowDoCommand(false);
-		this->engine->CallMethod(*this->instance, "Save", &savedata);
+		if (!this->engine->CallMethod(*this->instance, "Save", &savedata)) {
+			/* The script crashed in the Save function. We can't kill
+			 * it here, but do so in the next AI tick. */
+			SaveEmpty();
+			return;
+		}
 		AIObject::SetAllowDoCommand(backup_allow);
 
 		if (!sq_istable(savedata)) {
@@ -637,21 +647,21 @@ void AIInstance::Load(int version)
 	sq_pushbool(vm, true);
 }
 
-void AIInstance::CallLoad()
+bool AIInstance::CallLoad()
 {
 	HSQUIRRELVM vm = this->engine->GetVM();
 	/* Is there save data that we should load? */
 	SQBool res;
 	sq_getbool(vm, -1, &res);
 	sq_poptop(vm);
-	if (!res) return;
+	if (!res) return true;
 
 	if (!this->engine->MethodExists(*this->instance, "Load")) {
 		AILog::Warning("Loading failed: there was data for the AI to load, but the AI does not have a Load() function.");
 
 		/* Pop the savegame data and version. */
 		sq_pop(vm, 2);
-		return;
+		return true;
 	}
 
 	/* Go to the instance-root */
@@ -668,8 +678,9 @@ void AIInstance::CallLoad()
 
 	/* Call the AI load function. sq_call removes the arguments (but not the
 	 * function pointer) from the stack. */
-	sq_call(vm, 3, SQFalse, SQFalse);
+	if (SQ_FAILED(sq_call(vm, 3, SQFalse, SQFalse))) return false;
 
 	/* Pop 1) The version, 2) the savegame data, 3) the object instance, 4) the function pointer. */
 	sq_pop(vm, 4);
+	return true;
 }
diff --git a/src/ai/ai_instance.hpp b/src/ai/ai_instance.hpp
index 9c1aaca59..bf501dc23 100644
--- a/src/ai/ai_instance.hpp
+++ b/src/ai/ai_instance.hpp
@@ -100,7 +100,7 @@ public:
 	 * Call the AI Load function if it exists and data was loaded
 	 *  from a savegame.
 	 */
-	void CallLoad();
+	bool CallLoad();
 
 	/**
 	 * Load and discard data from a savegame.
diff --git a/src/ai/ai_scanner.cpp b/src/ai/ai_scanner.cpp
index db5acd90c..7e4e878d4 100644
--- a/src/ai/ai_scanner.cpp
+++ b/src/ai/ai_scanner.cpp
@@ -88,6 +88,8 @@ void AIScanner::ScanDir(const char *dirname, bool library_scan, bool library_rec
 			if (!FioCheckFileExists(info_script, AI_DIR) || !FioCheckFileExists(main_script, AI_DIR)) continue;
 
 			DEBUG(ai, 6, "Loading AI at location '%s'", main_script);
+			/* We don't care if one of the other scripst failed to load. */
+			this->engine->ResetCrashed();
 			this->engine->LoadScript(info_script);
 		} else {
 			char library_script[MAX_PATH];
@@ -100,6 +102,8 @@ void AIScanner::ScanDir(const char *dirname, bool library_scan, bool library_rec
 			if (!FioCheckFileExists(library_script, AI_LIBRARY_DIR) || !FioCheckFileExists(main_script, AI_LIBRARY_DIR)) continue;
 
 			DEBUG(ai, 6, "Loading AI Library at location '%s'", main_script);
+			/* We don't care if one of the other scripst failed to load. */
+			this->engine->ResetCrashed();
 			this->engine->LoadScript(library_script);
 		}
 	}
@@ -157,6 +161,7 @@ AIScanner::AIScanner() :
 	this->ScanAIDir();
 
 	/* Create the dummy AI */
+	this->engine->ResetCrashed();
 	extern void AI_CreateAIInfoDummy(HSQUIRRELVM vm);
 	AI_CreateAIInfoDummy(this->engine->GetVM());
 }
diff --git a/src/script/squirrel.cpp b/src/script/squirrel.cpp
index 602cc593d..0718f7945 100644
--- a/src/script/squirrel.cpp
+++ b/src/script/squirrel.cpp
@@ -24,7 +24,9 @@ void Squirrel::CompileError(HSQUIRRELVM vm, const SQChar *desc, const SQChar *so
 #endif
 
 	/* Check if we have a custom print function */
-	SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;
+	Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
+	engine->crashed = true;
+	SQPrintFunc *func = engine->print_func;
 	if (func == NULL) {
 		scfprintf(stderr, _SC("%s"), buf);
 	} else {
@@ -59,7 +61,9 @@ void Squirrel::RunError(HSQUIRRELVM vm, const SQChar *error)
 	/* Check if we have a custom print function */
 	SQChar buf[1024];
 	scsnprintf(buf, lengthof(buf), _SC("Your script made an error: %s\n"), error);
-	SQPrintFunc *func = ((Squirrel *)sq_getforeignptr(vm))->print_func;
+	Squirrel *engine = (Squirrel *)sq_getforeignptr(vm);
+	engine->crashed = true;
+	SQPrintFunc *func = engine->print_func;
 	if (func == NULL) {
 		scfprintf(stderr, _SC("%s"), buf);
 	} else {
@@ -156,6 +160,7 @@ void Squirrel::AddClassEnd()
 
 bool Squirrel::MethodExists(HSQOBJECT instance, const char *method_name)
 {
+	assert(!this->crashed);
 	int top = sq_gettop(this->vm);
 	/* Go to the instance-root */
 	sq_pushobject(this->vm, instance);
@@ -171,6 +176,7 @@ bool Squirrel::MethodExists(HSQOBJECT instance, const char *method_name)
 
 bool Squirrel::Resume(int suspend)
 {
+	assert(!this->crashed);
 	sq_resumecatch(this->vm, suspend);
 	return this->vm->_suspended != 0;
 }
@@ -182,6 +188,7 @@ void Squirrel::CollectGarbage()
 
 bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT *ret, int suspend)
 {
+	assert(!this->crashed);
 	/* Store the stack-location for the return value. We need to
 	 * restore this after saving or the stack will be corrupted
 	 * if we're in the middle of a DoCommand. */
@@ -199,7 +206,7 @@ bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT
 	}
 	/* Call the method */
 	sq_pushobject(this->vm, instance);
-	sq_call(this->vm, 1, ret == NULL ? SQFalse : SQTrue, SQTrue, suspend);
+	if (SQ_FAILED(sq_call(this->vm, 1, ret == NULL ? SQFalse : SQTrue, SQTrue, suspend))) return false;
 	if (ret != NULL) sq_getstackobj(vm, -1, ret);
 	/* Reset the top, but don't do so for the AI main function, as we need
 	 *  a correct stack when resuming. */
@@ -207,7 +214,25 @@ bool Squirrel::CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT
 	/* Restore the return-value location. */
 	this->vm->_suspended_target = last_target;
 
-	return this->vm->_suspended != 0;
+	return true;
+}
+
+bool Squirrel::CallStringMethodStrdup(HSQOBJECT instance, const char *method_name, const char **res, int suspend)
+{
+	HSQOBJECT ret;
+	if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
+	if (ret._type != OT_STRING) return false;
+	*res = strdup(ObjectToString(&ret));
+	return true;
+}
+
+bool Squirrel::CallIntegerMethod(HSQOBJECT instance, const char *method_name, int *res, int suspend)
+{
+	HSQOBJECT ret;
+	if (!this->CallMethod(instance, method_name, &ret, suspend)) return false;
+	if (ret._type != OT_INTEGER) return false;
+	*res = ObjectToInteger(&ret);
+	return true;
 }
 
 /* static */ bool Squirrel::CreateClassInstanceVM(HSQUIRRELVM vm, const char *class_name, void *real_instance, HSQOBJECT *instance, SQRELEASEHOOK release_hook)
@@ -258,6 +283,7 @@ Squirrel::Squirrel()
 	this->vm = sq_open(1024);
 	this->print_func = NULL;
 	this->global_pointer = NULL;
+	this->crashed = false;
 
 	/* Handle compile-errors ourself, so we can display it nicely */
 	sq_setcompilererrorhandler(this->vm, &Squirrel::CompileError);
@@ -459,3 +485,18 @@ void Squirrel::InsertResult(int result)
 {
 	vm->DecreaseOps(ops);
 }
+
+bool Squirrel::IsSuspended()
+{
+	return this->vm->_suspended != 0;
+}
+
+bool Squirrel::HasScriptCrashed()
+{
+	return this->crashed;
+}
+
+void Squirrel::ResetCrashed()
+{
+	this->crashed = false;
+}
diff --git a/src/script/squirrel.hpp b/src/script/squirrel.hpp
index b5b352bd0..5ce8675ed 100644
--- a/src/script/squirrel.hpp
+++ b/src/script/squirrel.hpp
@@ -12,6 +12,7 @@ private:
 	HSQUIRRELVM vm;          ///< The VirtualMachine instnace for squirrel
 	void *global_pointer;    ///< Can be set by who ever initializes Squirrel
 	SQPrintFunc *print_func; ///< Points to either NULL, or a custom print handler
+	bool crashed;            ///< True if the squirrel script made an error.
 
 	/**
 	 * The internal RunError handler. It looks up the real error and calls RunError with it.
@@ -111,11 +112,12 @@ public:
 
 	/**
 	 * Call a method of an instance, in various flavors.
+	 * @return False if the script crashed or returned a wrong type.
 	 */
 	bool CallMethod(HSQOBJECT instance, const char *method_name, HSQOBJECT *ret, int suspend = -1);
 	bool CallMethod(HSQOBJECT instance, const char *method_name, int suspend = -1) { return this->CallMethod(instance, method_name, NULL, suspend); }
-	const char *CallStringMethodStrdup(HSQOBJECT instance, const char *method_name, int suspend = -1) { HSQOBJECT ret; this->CallMethod(instance, method_name, &ret, suspend); return strdup(ObjectToString(&ret)); }
-	int CallIntegerMethod(HSQOBJECT instance, const char *method_name, int suspend = -1) { HSQOBJECT ret; this->CallMethod(instance, method_name, &ret, suspend); return ObjectToInteger(&ret); }
+	bool CallStringMethodStrdup(HSQOBJECT instance, const char *method_name, const char **res, int suspend = -1);
+	bool CallIntegerMethod(HSQOBJECT instance, const char *method_name, int *res, int suspend = -1);
 
 	/**
 	 * Check if a method exists in an instance.
@@ -191,6 +193,22 @@ public:
 	 * Tell the VM to remove \c amount ops from the number of ops till suspend.
 	 */
 	static void DecreaseOps(HSQUIRRELVM vm, int amount);
+
+	/**
+	 * Did the squirrel code suspend or return normally.
+	 * @return True if the function suspended.
+	 */
+	bool IsSuspended();
+
+	/**
+	 * Find out if the squirrel script made an error before.
+	 */
+	bool HasScriptCrashed();
+
+	/**
+	 * Reset the crashed status.
+	 */
+	void ResetCrashed();
 };
 
 #endif /* SQUIRREL_HPP */