Python State.env_set方法代码示例

# 需要导入模块: from State import State [as 别名]
# 或者: from State.State import env_set [as 别名]
    def _analyseStatement(self, astNumber, nodeNumber, state, recursionDepth):
        ''' Analyses a single statment
        Executes a statement returning its history. A return value is not provided.
        Handling "return" is done by observing the special return-Element in the
        env after a function has run through.
        There is no return value -> This is handled differently: There is a special return value in "env"
        this can be then be read when the function call returns! 
        To handle the histories: A certain history is NOT extended if its last event 
        is ret with the function beeing the same element the special "context.functionName" points 
        to in the current context -> Handle recursive calls later! 
        In Statements (despite for the return statement), merging the HistorieCollections 
        returned by the Expressions is the only thing, that is done concerning histories.

        Input:
            astNumber:      The ast the statement belongs to
            nodeNumber:     The node in the AST to analyse
            state:          The state with the current environment, the objects and the heap.

        Return:
            hist:           The HistoryCollection for this node
        '''
       
        ### Get Statement and type 
        ast = self.asts[astNumber]
        curNode = ast[nodeNumber]
        t = curNode["type"]
            
        ### Analyse the Statements based on type
        if t == "ExpressionStatement":
            tmpHis, ret = self._analyseExpression(astNumber, curNode["children"][0], state, recursionDepth)
            return tmpHis


        elif t in ["Program","BlockStatement","WithStatement"]:
            hist = HistoryCollection()
            if "children" in curNode:
                for i in curNode["children"]:
                    tmpHist = self._analyseStatement(astNumber, i, state, recursionDepth)
                    hist.addHistoryCollection(tmpHist)
            return hist

        if t in ["EmptyStatement", "DebuggerStatement"]:
            return HistoryCollection()

        # Control Flow (ignore completly, TODO)
        if t in ["BreakStatement", "ContinueStatement"]:
            return HistoryCollection()
        elif t == "ReturnStatement":
            # Do nothing for returns without return value
            if not "children" in curNode:
                return HistoryCollection()

            # Extend the the "__return__" variable and add the "return" statement to the history.
            hist, ret = self._analyseExpression(astNumber, curNode["children"][0],state, recursionDepth)
            if ret:
                returnObject = state.getTarget(ret)
                state.env_set("__return__", returnObject)# Merging is done automatically
                if returnObject != None:
                    hist.addEventToHistory(returnObject, state.functionName,"ret", state.functionName)
            return hist

        # Choice
        elif t == "IfStatement":
            hist, ret = self._analyseExpression(astNumber, curNode["children"][0], state, recursionDepth)
            hist.tagAsSpecialNode("ic")
            thenState = state.copy()
            hist_then = self._analyseStatement(astNumber, curNode["children"][1], thenState, recursionDepth)
            # Check whether else is given
            if len(curNode["children"]) == 3:
                elseState = state.copy()
                hist_else = self._analyseStatement(astNumber, curNode["children"][2], elseState, recursionDepth)
                state.mergeIn([thenState,elseState])
                hist.addHistoriesConditional([hist_then,hist_else])
            else:
                hist.addHistoriesConditional([hist_then,HistoryCollection()])
                state.mergeIn([thenState])
            return hist

        elif t == "SwitchStatement":
            hist, ret = self._analyseExpression(astNumber, curNode["children"][0], state, recursionDepth)
            hist.tagAsSpecialNode("sc")
            condHistories = []
            condStates = []
            preceedingCaseConditions = []
            for case in curNode["children"][1:]:
                condStates.append(state.copy())
                case = ast[case]
                innerHist = HistoryCollection()
                # Handle previous case conditions
                for precCaseCond in preceedingCaseConditions:
                    tmpHist, ret = self._analyseExpression(astNumber, precCaseCond, condStates[-1], recursionDepth)
                    innerHist.addHistoryCollection(tmpHist)
                # Handle current case
                isDefault = len(case["children"]) == 1
                if not isDefault:
                    preceedingCaseConditions.append(case["children"][0]);
                    tmpHist, ret = self._analyseExpression(astNumber, case["children"][0], condStates[-1], recursionDepth)
                    tmpHist.tagAsSpecialNode("cc")
                    innerHist.addHistoryCollection(tmpHist)
                    tmpHist = self._analyseStatement(astNumber, case["children"][1], condStates[-1], recursionDepth)
#.........这里部分代码省略.........