编译原理标准实验报告.docx

1、编译原理标准实验报告编译原理实验报告江苏科技大学电子信息学院2005年8月19日 实验一：词法分析设计 2实验二：LL(1)预测分析 10实验三：逆波兰表达式的产生及计算 26实验四：SLR(1)语法分析设计 48 实验五：应用DAG进行局部优化 52 实验一 词法分析设计一实验目的通过本实验的编程实践，使学生了解词法分析的任务，掌握词法分析程序设计的原理和构造方法，使学生对编译的基本概念、原理和方法有完整的和清楚的理解，并能正确地、熟练地运用。二实验内容用VC+/VB/JAVA语言实现对C语言子集的源程序进行词法分析。通过输入源程序从左到右对字符串进行扫描和分解，依次输出各个单词的内部编码及

2、单词符号自身值；若遇到错误则显示“Error”，然后跳过错误部分继续显示 ；同时进行标识符登记符号表的管理。三实验步骤1基于实验的内容，构造程序所需的模块2根据已建构的模块，写出各个模块的相应程序代码3在主函数中调用模块来完成所要得到的效果四参考答案1源程序# # 存在问题：如何能较好的判断符号的优先级？ # #* 定义变量*Dim str_stack(1 To 20) As String, str_input As String, str_output As String, current As StringDim stack_p As Double, str_feihouzhui As S

3、tring* 函数定义*Private Sub chansheng()Dim i As Double, j As Double, int_length As Long, stack_top As String, temp_stack_p As DoubleDim str_temp As String, int_length2 As Long, success As Boolean, str_temp_stack(1 To 20) As StringDim msg As Doublesuccess = TrueFor i = 1 To 20 str_stack(i) = Nextstr_inpu

4、t = : str_output = : current = i = 1: j = 1: stack_p = 1temp_stack_p = 0 用于存放优先级较高的运算符的临时堆栈的指针str_input = InputBox(请输入待转换的非后缀式：, 输入非后缀式, (a+b*c)*d, 3000, 5000) & #str_feihouzhui = str_inputint_length = Len(str_input)int_length2 = int_lengthgrid.Rows = 100 初始化表格控件grid.Cols = 4grid.TextMatrix(0, 0) =

5、当前符号grid.TextMatrix(0, 1) = 输入区grid.TextMatrix(0, 2) = 符号栈grid.TextMatrix(0, 3) = 输出区grid.ColWidth(0) = 2100 设置列宽grid.ColWidth(1) = 2100grid.ColWidth(2) = 2075grid.ColWidth(3) = 3100Do While (success)current = Mid(str_input, 1, 1)l0: stack_top = str_stack(stack_p)str_temp = Select Case current Case

6、0 To 9, a To z str_output = str_output & current int_length2 = int_length2 - 1 Case *, / Select Case stack_top Case str_stack(stack_p) = current int_length2 = int_length2 - 1 Case *, /, +, -, ( stack_p = stack_p + 1 str_stack(stack_p) = current int_length2 = int_length2 - 1 End Select Case +, - Sele

7、ct Case stack_top Case str_stack(stack_p) = current For j = temp_stack_p To 1 Step -1 If str_temp_stack(temp_stack_p) Then stack_p = stack_p + 1 str_stack(stack_p) = str_temp_stack(j) temp_stack_p = temp_stack_p - 1 End If Next int_length2 = int_length2 - 1 Case *, / str_output = str_output & str_st

8、ack(stack_p) 若优先级低于栈顶运算符，则弹出栈顶运算符并输出 If stack_p 1 Then stack_p = stack_p - 1 Else str_stack(stack_p) = End If GoTo l0 Case +, -, ( stack_p = stack_p + 1 str_stack(stack_p) = current int_length2 = int_length2 - 1 For j = temp_stack_p To 1 Step -1 If str_temp_stack(temp_stack_p) Then stack_p = stack_p

9、 + 1 str_stack(stack_p) = str_temp_stack(j) temp_stack_p = temp_stack_p - 1 End If Next End Select Case ( Select Case stack_top Case str_stack(stack_p) = current int_length2 = int_length2 - 1 Case *, /, +, -, ( stack_p = stack_p + 1 str_stack(stack_p) = current int_length2 = int_length2 - 1 End Sele

10、ct Case ) Select Case stack_top Case msg = MsgBox(错误，没有匹配的“（”。, 出错, 1) Case *, /, +, - str_output = str_output & str_stack(stack_p) If stack_p 1 Then stack_p = stack_p - 1 End If Case ( If stack_p 1 Then stack_p = stack_p - 1 Else str_stack(stack_p) = End If int_length2 = int_length2 - 1 End SelectE

11、nd Selectstr_input = Right(str_input, int_length2)For j = 1 To stack_p str_temp = str_temp & str_stack(j)NextIf current = # Then For j = stack_p To 1 Step -1 If Not str_stack(stack_p) = Then str_output = str_output & str_stack(j) If stack_p 1 Then stack_p = stack_p - 1 Else str_stack(stack_p) = End

12、If End If Next success = FalseEnd Ifgrid.TextMatrix(i, 0) = currentgrid.TextMatrix(i, 1) = str_inputgrid.TextMatrix(i, 2) = str_tempgrid.TextMatrix(i, 3) = str_outputi = i + 1LoopEnd SubPrivate Sub calculate()Dim msg As Double, int_length As Double, i As Double, j As Double, int_length2 As DoubleDim

13、 fuzhi(1 To 20) As String, m As Double, n As Double, int_temp As DoubleIf cmd_chansheng.Enabled = False Then msg = MsgBox(是否对已有逆波兰式进行计算？, vbYesNo, 提示) Select Case msg Case 6 GoTo l1 Case 7 Call chansheng End SelectElse Call chanshengEnd Ifl1: str_input = str_outputstr_temp = InputBox(请以“=”的形式给待求算术表达

14、式中的变量赋值，注意，各变量间以“，”隔开。, 赋值, a=1,b=2,c=3,d=4, 3000, 5000)int_length2 = Len(str_temp)m = 1: n = 2For i = 1 To int_length2current = Mid(str_temp, i, 1)Select Case current Case a To z fuzhi(m) = current m = m + 2 Case 0 To 9 fuzhi(n) = current n = n + 2End SelectNextPicture1.Print 转换前的非后缀式为: & str_feiho

15、uzhuiPicture1.Print 待求的算术表达式为: & str_outputPicture1.Print 各变量的值为: & str_tempstack_p = 1int_length = Len(str_input)For i = 1 To int_lengthcurrent = Mid(str_input, i, 1)Select Case current Case a To z For j = 1 To m Step 2 If current = fuzhi(j) Then str_stack(stack_p) = fuzhi(j + 1) End If Next stack_

16、p = stack_p + 1 Case + stack_p = stack_p - 1 int_temp = CDbl(str_stack(stack_p - 1) + CDbl(str_stack(stack_p) str_stack(stack_p - 1) = CStr(int_temp) Case - stack_p = stack_p - 1 int_temp = CDbl(str_stack(stack_p - 1) - CDbl(str_stack(stack_p) str_stack(stack_p - 1) = CStr(int_temp) Case * stack_p =

17、 stack_p - 1 int_temp = CDbl(str_stack(stack_p - 1) * CDbl(str_stack(stack_p) str_stack(stack_p - 1) = CStr(int_temp) Case / stack_p = stack_p - 1 int_temp = CDbl(str_stack(stack_p - 1) / CDbl(str_stack(stack_p) str_stack(stack_p - 1) = CStr(int_temp) Case 0 To 9 str_stack(stack_p) = current stack_p

18、 = stack_p + 1 End SelectNextIf str_stack(stack_p) ThenPicture1.Print 计算结果为: & str_stack(stack_p - 1)End IfEnd Sub* 定义操作*Private Sub cmd_chansheng_Click()cmd_chansheng.Enabled = Falsecmd_calculate.Enabled = TrueCall chanshengEnd SubPrivate Sub cmd_calculate_Click()cmd_calculate.Enabled = FalseCall c

19、alculateEnd SubPrivate Sub cmd_exit_Click()EndEnd SubPrivate Sub cmd_main_Click()Form3.HideForm_main.ShowEnd SubPrivate Sub cmd_previous_Click()Form3.HideForm2.ShowEnd SubPrivate Sub cmd_reflesh_Click()cmd_chansheng.Enabled = Truecmd_calculate.Enabled = Truegrid.ClearPicture1.ClsEnd Sub2运行结果实验二 LL(1

20、)预测分析一实验目的 通过完成预测分析法的语法分析程序，了解预测分析法和递归子程序法的区别和联系。使学生了解语法分析的功能，掌握语法分析程序设计的原理和构造方法，训练学生掌握开发应用程序的基本方法。有利于提高学生的专业素质，为培养适应社会多方面需要的能力。二实验内容1. 对下列文法，用LL（1）分析法对任意输入的符号串进行分析： （1）E-TG（2）G-+TG|TG（3）G-（4）T-FS（5）S-*FS|/FS（6）S-（7）F-(E)（8）F-i2. 构造预测分析表，并利用分析表和一个栈来实现对上述程序设计语言的分析程序。三实验步骤1基于实验的内容，构造程序所需的模块2根据已建构的模块，写

21、出各个模块的相应程序代码3在主函数中调用模块来完成所要得到的效果四参考答案1源程序Option ExplicitDim zjf As StringDim stack(50) As StringDim qu(50) As StringDim m, n As IntegerPrivate Sub Form_Activate() RichTextBox1.Width = Me.Width RichTextBox1.Height = CFFX.HeightEnd SubPrivate Sub Toolbar1_ButtonClick(ByVal Button As ComctlLib.Button)D

22、im FileName As StringDim k, t As IntegerDim es As Integerk = 0Select Case Button.KeyCase Is = xj RichTextBox1.Text = RichTextBox1.Width = Me.Width RichTextBox1.Height = CFFX.Height MSFlexGrid1.Visible = False RichTextBox1.Visible = TrueCase Is = dk CommonDialog1.Filter = TXT文件|*.TXT 打开文件对话框 CommonDi

23、alog1.ShowOpen FileName = CommonDialog1.FileName RichTextBox1.FileName = FileName RichTextBox1.Width = Me.Width RichTextBox1.Height = CFFX.Height StatusBar1.Panels(1).Text = 徐天霞 & FileName MSFlexGrid1.Visible = False RichTextBox1.Visible = TrueCase Is = bc CommonDialog1.DialogTitle = 保存 CommonDialog

24、1.Filter = 文本文件(*.txt)|*.txt CommonDialog1.ShowSave FileName = CommonDialog1.FileName RichTextBox1.SaveFile FileName StatusBar1.Panels(1).Text = 徐天霞 & FileName Case Is = fxWhile Mid(RichTextBox1.Text, k + 1, 1) qu(k) = Mid(RichTextBox1.Text, k + 1, 1) k = k + 1Wend MSFlexGrid1.Clear es = LL() RichTe

25、xtBox1.Width = Me.Width RichTextBox1.Height = Me.Height / 2 MSFlexGrid1.Visible = True If es 0 Then MsgBox 分析成功！ Else MsgBox 分析失败！ End If For t = 0 To 49 qu(t) = Next tCase Is = tc Unload MeEnd SelectEnd SubPublic Function LL() As IntegerDim i, j As IntegerDim F As BooleanDim k As IntegerDim char2 A

26、s StringWith CFFX.MSFlexGrid1 .Cols = 5 .Rows = 100 For k = 1 To 4 .ColWidth(k) = 1600 Next k .Row = 0 .Col = 0 .Text = 步 骤 .Col = 1 .Text = 分析栈 .Col = 2 .Text = 剩余输入串 .Col = 3 .Text = 所用产生式 .Col = 4 .Text = 动 作 End Withn = 0m = 1zjf = i()+-*/stack(0) = #stack(1) = EF = Truej = 1i = 0With CFFX.MSFlexGrid1 .Row = m .Col = 0 .Text = Str(n) .Col = 1 k = 0 char2 = While stack(k) char2 = char2 & stack(k)k = k + 1Text = char2Wend.Col = 2k = 0char2 = While qu(k) char2 = char2 & qu(k)