作者：yxin1322 blog：http://blog.csdn.net/yxin1322 转载请注明出处
这个程序是我《编译原理》的期末大作业，要求实现PL0到C语言的编译器，其实叫翻译器更贴切点。程序的实现目标是能把具有基本Pascal语法的pl0语言源程序转换成C语言程序。pl0支持变量定义、条件语句、循环语句、赋值语句，变量的控制台输入与输出。翻译出的C语言程序需能被常见的C编译器编译通过。
本程序分为两大模块：词法分析模块和语法制导翻译及输出模块。
词法分析模块：通过程序指定一个由pl0语言编写的程序源文件，词法分析器能够将源文件内容分解为一组单词序列，并判别每个单词的所属类别（分别有运算符、分界符、关键字、变量名和数字），当遇到非法字符串时，能报出错误发生的位置。如果分析成功而未遇到任何错误，则词法分析器返回给编译程序一个单词集合，以用来做语法分析。每个单词存放在一个WordTableEntry结果中。
词法分析模块代码如下：GETSYM.CS
1 /*2 code by: yxin1322WordTableEntry.CS
3 date: 2005.6
4 blog: http://blog.csdn.net/yxin1322
5 Email: yxin1322@gmail.com
6 */
7
8
9 using System;
10 using System.Collections;
11 using System.Text.RegularExpressions;
12 using System.IO;
13
14 namespace GETSYM
15 {
16 /// <summary>
17 /// 词法分析器类
18 /// </summary>
19 public class GETSYM
20 {
21 public static string[] OperatorList={"+","-","*","/",":=","#",
22 ">=","<=","<",">","=","&&","||"}; //运算符列表，可以扩充
23 public static string[] Bound_OperatorList={",",".",";","(",")"}; //分界符列表，可以扩充
24 public static string[] Reserved_WordsList=
25 {"CONST","VAR","PROCEDURE","BEGIN","END","ODD","IF",
26 CALL","WHILE","READ","DO","WRITE","THEN"}; //关键字列表，可以扩充
27
28
29 public ArrayList WordTable; //存储词法分析后的单词列表，列表的元素是WordTableEntry的对象
30 private string pl0FilePath; //存储需要分析的pl0源文件路径
31
32 //默认构造函数
33 public GETSYM()
34 {
35 WordTable=new ArrayList();
36 PL0FilePath="";
37 }
38
39 //初始化文件路径的构造函数
40 public GETSYM(string filepath)
41 {
42 WordTable=new ArrayList();
43 PL0FilePath=filepath;
44 }
45
46 //属性
47 public string PL0FilePath
48 {
49 get{return pl0FilePath;}
50 set{pl0FilePath=value;}
51 }
52
53 //将分析好的单词表写入文件
54 public void WriteSYMToFile()
55 {
56 if(pl0FilePath.Equals(""))
57 {
58 System.Console.WriteLine("Unknown output file name!");
59 return ;
60 }
61
62 string temfilename=Regex.Replace(PL0FilePath,@"./w+$","");
63 string OutPutFileName=temfilename+".SYM";
64
65 System.IO.StreamWriter sw=null;//创建输出文件
66
67 sw=File.CreateText(OutPutFileName);
68
69 sw.WriteLine("//------------------------------------------------------------");
70 sw.WriteLine("//pl0语言词法分析器 v0.2 Copyright 2005 yxin1322");
71 sw.WriteLine("//单词表创建自文件[{0}]",pl0FilePath);
72 sw.WriteLine("//生成时间:{0}",System.DateTime.Now.ToString());
73 sw.WriteLine("//------------------------------------------------------------");
74
75 System.Console.WriteLine("/n生成单词表.../n");
76 for(int i=0;i<WordTable.Count;i++)
77 {
78 sw.WriteLine("{0,15}: {1,-15}",((WordTableEntry)WordTable[i]).WordType.ToString(),
79 ((WordTableEntry)WordTable[i]).Word);
80 }
81 sw.Close();
82
83 System.Console.WriteLine("已经将单词写入文件：{0}",OutPutFileName);
84 }
85
86 //对pl0源文件进行分析，划分出单词并分析其类别，存储进WoedTable
87 public bool getSYM()
88 {
89 System.Console.WriteLine("------------------------------------------------------------");
90 System.Console.WriteLine("[pl0语言词法分析器 v0.2] Copyright 2005 yxin1322");
91 System.Console.WriteLine("------------------------------------------------------------");
92
93 ArrayList ErrorList=new ArrayList();
94 if(pl0FilePath.Equals(""))
95 {
96 System.Console.WriteLine("你没有指定源文件！");
97 return false;
98 }
99 if(!File.Exists(pl0FilePath))
100 {
101 System.Console.WriteLine("找不到指定源文件！");
102 return false;
103 }
104 else
105 {
106 System.Console.WriteLine("正在对文件内容进行词法分析...");
107 StreamReader sr=File.OpenText(PL0FilePath);
108
109 int LineNum=0; //对当前分析的行进行记数
110 string Line=sr.ReadLine();//读入第一行
111
112 LineNum++;
113 while(Line!=null)
114 {
115 if(Regex.IsMatch(Line,@"^//")) //忽略注释
116 {
117 Line=sr.ReadLine();
118 LineNum++;
119 }
120
121 else
122 {
123 Line=Regex.Replace(Line,@"//.*$","");
124
125 for(int i=0;i<OperatorList.Length;i++) //对运算符和界符两边添加空格
126 Line=Line.Replace(OperatorList[i]," "+OperatorList[i]+" ");
127 for(int i=0;i<Bound_OperatorList.Length;i++)
128 Line=Line.Replace(Bound_OperatorList[i]," "+Bound_OperatorList[i]+" ");
129
130 Line=Regex.Replace(Line,@"/s+"," ");//将多个空格替换成一个空格
131 Line=Line.Trim(); //去掉一行两边的空格
132
133 string [] WordSplit=Regex.Split(Line," ");//用空格分割字符串
134 for(int k=0;k<WordSplit.Length;k++)//遍历分割后的字符串
135 {
136 string str1=WordSplit[k];
137 string str2=(k<WordSplit.Length-1)?WordSplit[k+1]:"";
138
139 if(str1.Equals(""))
140 continue;
141 if(GETSYM.IsOperator(ref str1,str2,ref k))
142 WordTable.Add(new WordTableEntry(Word_Type.Operator,str1));
143 else if(GETSYM.IsNumber(str1))
144 WordTable.Add(new WordTableEntry(Word_Type.Number,str1));
145 else if(GETSYM.IsBound_Operator(str1))
146 WordTable.Add(new WordTableEntry(Word_Type.Bound_Operator,str1));
147 else if(GETSYM.IsReserved_Words(str1))
148 WordTable.Add(new WordTableEntry(Word_Type.Reserved_Words,str1));
149 else if(GETSYM.IsIdentifier(str1))
150 WordTable.Add(new WordTableEntry(Word_Type.Identifier,str1));
151 else
152 {
153 string error="Error Accur in Line:"+LineNum+" '"+str1+"'不是合法的单词";
154 ErrorList.Add(error);
155 }
156
157 }
158
159 //System.Console.WriteLine(Line);
160 Line=sr.ReadLine();
161 LineNum++;
162 }
163
164 }
165 sr.Close();
166 }
167 if(ErrorList.Count==0)
168 return true;
169 else
170 {
171 for(int i=0;i<ErrorList.Count;i++)
172 Console.WriteLine((string)ErrorList[i]);
173 return false;
174 }
175 }
176
177 public static bool IsBound_Operator(string a)
178 {
179 foreach(string str in Bound_OperatorList)
180 {
181 if(a.Equals(str))
182 return true;
183 }
184 return false;
185 }
186
187 public static bool IsOperator(ref string a,string b,ref int c)
188 {
189 string tem=a+b;
190 foreach(string str in OperatorList)
191 {
192 if(tem.Equals(str))
193 {
194 a=a+b;
195 c++;
196 return true;
197 }
198 }
199 foreach(string str in OperatorList)
200 {
201 if(a.Equals(str))
202 return true;
203 }
204 return false;
205
206 }
207
208 public static bool IsReserved_Words(string a)
209 {
210 foreach(string str in Reserved_WordsList)
211 {
212 if((a.ToUpper()).Equals(str))
213 return true;
214 }
215 return false;
216 }
217
218 public static bool IsNumber(string str)
219 {
220 Regex r=new Regex(@"^/d+$");
221 if(r.IsMatch(str))
222 return true;
223 else
224 return false;
225 }
226 public static bool IsIdentifier(string str)
227 {
228 Regex r=new Regex(@"^[a-zA-Z][a-zA-Z0-9]*$");
229 if(r.IsMatch(str))
230 return true;
231 else
232 return false;
233
234 }
235
236 }
237 }
1 /* code by: yxin13222 date: 2005.63 blog: http://blog.csdn.net/yxin13224 Email: yxin1322@gmail.com5 */6 7 using System;8 9 //字符串类型定义10 public enum Word_Type{Reserved_Words,Number,Operator,Bound_Operator,Identifier,other}11 namespace GETSYM12 {13 14 15 /// <summary>16 /// WordTalbeEntry定义一个词汇表的节点17 /// </summary>18 public class WordTableEntry19 {20 21 22 23 private Word_Type wordtype;//单词种类24 private string word;//单词值25 26 public WordTableEntry() //默认构造函数27 {28 wordtype=Word_Type.other;29 word="";30 }31 32 public WordTableEntry(Word_Type a,string b)//带参数的构造函数33 {34 wordtype=a;35 word=b;36 }37 38 public string Word //属性39 {40 get41 {42 return word;43 }44 set45 {46 word=value;47 }48 }49 50 public Word_Type WordType //属性51 {52 get53 {54 return wordtype;55 }56 set57 {58 wordtype=value;59 }60 }61 62 63 }64 }
语法制导翻译及输出模块:为了翻译的简便，我采用了语法制导翻译的方式，即一边进行语法分析，一边将pl0语言翻译成C语言，若遇到语法错误则停止翻译，报告错误。在实现方式上采用了递归子程序法，递归子程序法简单直观，只要分析出了pl0语言的语法范式（EBNF），就能为每个范式构造对应的子程序。这里我已经得到了pl0语言的EBNF，如下：
〈程序〉∷=〈分程序〉．
〈分程序〉∷=[〈常量说明部分〉][〈变量说明部分〉][〈过程说明部分〉]〈语句〉
〈常量说明部分〉∷=CONST〈常量定义〉 {，〈常量定义〉}；
〈常量定义〉∷=〈标识符〉=〈无符号整数〉
〈无符号整数〉∷=〈数字〉{〈数字〉}
〈变量说明部分〉∷=VAR〈标识符〉{，〈标识符〉}；
〈标识符〉∷=〈字母〉{〈字母〉|〈数字〉}
〈过程说明部分〉∷=〈过程首部〉〈分程序〉{；〈过程说明部分〉}；
〈过程首部〉∷=PROCEDURE〈标识符〉；
〈语句〉∷=〈赋值语句〉|〈条件语句〉|〈当型循环语句〉|
〈过程调用语句〉|〈读语句〉|〈写语句〉|〈复合语句〉|〈空〉
〈赋值语句〉∷=〈标识符〉∶=〈表达式〉
〈复合语句〉∷=BEGIN〈语句〉{；〈语句〉}END
〈条件〉∷=〈表达式〉〈关系运算符〉〈表达式〉|ODD〈表达式〉
〈表达式〉∷=[+|-]〈项〉{〈加法运算符〉〈项〉}
〈项〉∷=〈因子〉{〈乘法运算符〉〈因子〉}
〈因子〉∷=〈标识符〉|〈无符号整数〉|'('〈表达式〉')'
〈加法运算符〉∷=+|-
〈乘法运算符〉∷=*|/
〈关系运算符〉∷=#|=|＜|＜=|＞|＞=
〈条件语句〉∷=IF〈条件〉THEN〈语句〉
〈过程调用语句〉∷=CALL〈标识符〉
〈当型循环语句〉∷=WHILE〈条件〉DO〈语句〉
〈读语句〉∷=READ'('〈标识符〉{，〈标识符〉}')'
〈写语句〉∷=WRITE'('〈表达式〉{，〈表达式〉}')'
〈字母〉∷=a|b|…|X|Y|Z
〈数字〉∷=0|1|2|…|8|9
根据EBNF就可以很快写出语法分析和翻译程序，代码如下：
1 /*------------------------------------------------------------2 <pl0 to C Convertor v0.1> Copyright 20053 code by: yxin13224 date: 2005.65 blog: http://blog.csdn.net/yxin13226 Email: yxin1322@gmail.com7 运行环境：.Net FrameWork 1.18 --------------------------------------------------------------*/9 10 using System;11 using System.Collections;12 using System.IO;13 using System.Text.RegularExpressions;14 using GETSYM;15 16 namespace Pascal_to_C_Convertor17 {18 /// <summary>19 /// Pascal_to_C 的摘要说明。20 /// 进行Pascal到C转换的实现类21 /// </summary>22 public class Pascal_to_C23 {24 private string pascal_file_name;//pascal源文件名25 static private int word_count;//分析pascal单词表的记数器26 private ArrayList pascal_word_table;27 public ArrayList C_Source;//存储转换好的C语言源程序28 public ArrayList ErrorList;29 30 31 public Pascal_to_C()32 {33 this.pascal_file_name="";34 word_count=-1;//初始值为-135 this.pascal_word_table=new ArrayList();36 this.C_Source=new ArrayList();37 this.ErrorList=new ArrayList();38 39 }40 41 public Pascal_to_C(string filename)42 {43 this.PascalFileName=filename;44 word_count=-1;//初始值为-145 this.pascal_word_table=new ArrayList();46 this.C_Source=new ArrayList();47 this.ErrorList=new ArrayList();48 }49 50 public string PascalFileName51 {52 get{return this.pascal_file_name;}53 set{this.pascal_file_name=value;}54 }55 56 //获得分解好的PASCAL单词表57 private ArrayList LoadWordTableFromFile()58 {59 GETSYM.GETSYM gs=new GETSYM.GETSYM(this.PascalFileName);60 if(gs.getSYM())61 return gs.WordTable;62 else63 return null;64 }65 66 public bool CreateCSourceCode()67 {68 this.pascal_word_table=this.LoadWordTableFromFile();//得到pl0单词表69 70 if(this.pascal_word_table==null)//词法分析出错71 {72 return false;73 }74 this.pascal_word_table.Add(new WordTableEntry(Word_Type.other,"####"));//添加单词表尾75 76 WordTableEntry w=this.getNextWord();77 78 System.Console.WriteLine("/n正在进行语法分析...");79 80 this.Program(ref w); //调用递归分析程序81 if(word_count==this.pascal_word_table.Count-1 && ErrorList.Count==0)82 {83 return true;84 }85 else86 {87 this.PrintErrorList();//打印错误列表88 return false;89 }90 }91 92 //得到pascal单词表的下一个单词93 private WordTableEntry getNextWord()94 {95 word_count++;96 return ((WordTableEntry)this.pascal_word_table[word_count]);97 }98 99 //递归子程序从次开始100 101 //"程序"递归程序102 //〈程序〉∷=〈分程序〉.103 private void Program(ref WordTableEntry w)104 {105 Subprogram(ref w);106 if(!w.Word.Equals("."))107 {108 ErrorList.Add("分程序结束期待一个.");109 }110 else111 {112 this.C_Source.Add("/n");113 114 w=this.getNextWord();115 }116 117 }118 119 //"分程序"递归程序120 //〈分程序〉∷=[〈常量说明部分〉][〈变量说明部分〉][〈过程说明部分〉]〈语句〉121 private void Subprogram(ref WordTableEntry w)122 {123 if(w.Word.ToUpper().Equals("CONST"))124 this.ConstValueExplain(ref w);125 if(w.Word.ToUpper().Equals("VAR"))126 this.VariableExplain(ref w);127 if(w.Word.ToUpper().Equals("PROCEDURE"))128 this.ProcedureExplain(ref w);129 this.Sentence(ref w);130 131 }132 133 //"常量说明部分"递归程序134 //〈常量说明部分〉∷=CONST〈常量定义〉 {，〈常量定义〉}；135 private void ConstValueExplain(ref WordTableEntry w)136 {137 if(w.Word.ToUpper().Equals("CONST"))138 {139 this.C_Source.Add("const int");140 141 w=this.getNextWord();142 this.ConstValue(ref w);143 while(w.Word.ToUpper().Equals(","))144 {145 this.C_Source.Add(",");146 147 w=this.getNextWord();148 this.ConstValue(ref w);149 }150 if(!w.Word.Equals(";"))151 {152 ErrorList.Add("常量定义后没有加分号!");153 }154 else155 {156 this.C_Source.Add(";/n");157 w=this.getNextWord();158 }159 160 }161 }162 163 //"常量定义"递归程序164 //〈常量定义〉∷=〈标识符〉=〈无符号整数〉165 private void ConstValue(ref WordTableEntry w)166 {167 this.Identifier(ref w);168 169 if(w.Word.Equals("="))170 {171 this.C_Source.Add("=");172 173 w=this.getNextWord();174 this.UnsignedNumber(ref w);175 }176 else177 {178 this.ErrorList.Add("变量定义缺少等号!");179 }180 }181 182 //"无符号整数"递归程序183 //〈无符号整数〉∷=〈数字〉{〈数字〉}184 private void UnsignedNumber(ref WordTableEntry w)185 {186 if(w.WordType==Word_Type.Number)187 {188 this.C_Source.Add(w.Word);189 190 w=this.getNextWord();191 }192 else193 ErrorList.Add("期望一个无符号整数!");194 }195 196 //"变量说明部分"递归程序197 //〈变量说明部分〉∷=VAR〈标识符〉{，〈标识符〉}；198 private void VariableExplain(ref WordTableEntry w)199 {200 if(w.Word.ToUpper().Equals("VAR"))201 {202 this.C_Source.Add("int");203 204 w=this.getNextWord();205 this.Identifier(ref w);206 while(w.Word.ToUpper().Equals(","))207 {208 this.C_Source.Add(",");209 210 w=this.getNextWord();211 this.Identifier(ref w);212 }213 if(!w.Word.Equals(";"))214 {215 ErrorList.Add("变量定义后没有加分号!");216 }217 else218 {219 this.C_Source.Add(";/n");220 221 w=this.getNextWord();222 }223 224 }225 }226 227 //"标识符"递归程序228 //〈标识符〉∷=〈字母〉{〈字母〉|〈数字〉}229 private void Identifier(ref WordTableEntry w)230 {231 if (w.WordType==Word_Type.Identifier)232 {233 this.C_Source.Add(w.Word);234 235 w=this.getNextWord();236 }237 else238 {239 ErrorList.Add("期望一个标识符！");240 }241 }242 243 //"过程说明部分"递归程序244 //〈过程说明部分〉∷=〈过程首部〉〈分程序〉{；〈过程说明部分〉}；245 private void ProcedureExplain(ref WordTableEntry w)246 {247 this.ProcedureHead(ref w);248 249 this.C_Source.Add("{");250 251 this.Subprogram(ref w);252 while(w.Word.Equals(";")) 253 {254 this.C_Source.Add(";/n");255 256 w=this.getNextWord();257 this.ProcedureExplain(ref w);258 }259 if (!w.Word.Equals(";"))260 {261 ErrorList.Add("过程的结束没有加分号！");262 }263 else264 {265 this.C_Source.Add(";}/n");266 267 w=this.getNextWord();268 }269 }270 271 //"过程首部"递归程序272 //〈过程首部〉∷=PROCEDURE〈标识符〉；273 private void ProcedureHead(ref WordTableEntry w)274 {275 if(w.Word.ToUpper().Equals("PROCEDURE"))276 {277 this.C_Source.Add("void");278 279 w=this.getNextWord();280 this.Identifier(ref w);281 if (!w.Word.Equals(";"))282 {283 ErrorList.Add("过程名后缺少分号！");284 }285 else286 {287 this.C_Source.Add("()/n");288 w=this.getNextWord();289 }290 }291 else292 ErrorList.Add("过程需要从关键字PROCEDURE开始！");293 }294 295 //"语句"递归程序296 //〈语句〉∷=〈赋值语句〉|〈条件语句〉|〈当型循环语句〉|〈过程调用语句〉|〈读语句〉|〈写语句〉|〈复合语句〉|〈空〉297 private void Sentence(ref WordTableEntry w)298 {299 if (w.WordType==Word_Type.Identifier) 300 {301 this.EvaluateSentence(ref w);302 }303 else if (w.Word.ToUpper().Equals("IF"))304 {305 this.ConditionSentence(ref w);306 }307 else if (w.Word.ToUpper().Equals("WHILE"))308 {309 this.WhileSentence(ref w);310 }311 else if (w.Word.ToUpper().Equals("CALL"))312 {313 this.WhileSentence(ref w);314 }315 else if (w.Word.ToUpper().Equals("READ"))316 {317 this.ReadSentence(ref w);318 }319 else if (w.Word.ToUpper().Equals("WRITE"))320 {321 this.WriteSentence(ref w);322 }323 else if (w.Word.ToUpper().Equals("BEGIN"))324 {325 this.ComplexSentence(ref w);326 }327 else328 {329 ;330 }331 }332 333 //"赋值语句"递归程序334 //〈赋值语句〉∷=〈标识符〉∶=〈表达式〉335 private void EvaluateSentence(ref WordTableEntry w)336 {337 this.Identifier(ref w);338 if (w.Word.Equals(":="))339 {340 this.C_Source.Add("=");341 342 w=this.getNextWord();343 this.Expression(ref w);344 }345 else346 ErrorList.Add("赋值语句缺少等号！");347 }348 349 //"复合语句"递归程序350 //〈复合语句〉∷=BEGIN〈语句〉{；〈语句〉}END351 private void ComplexSentence(ref WordTableEntry w)352 {353 if (w.Word.ToUpper().Equals("BEGIN"))354 {355 this.C_Source.Add("{/n");356 357 w=this.getNextWord();358 this.Sentence(ref w);359 while(w.Word.Equals(";"))360 {361 this.C_Source.Add(";/n");362 363 w=this.getNextWord();364 this.Sentence(ref w);365 }366 367 this.C_Source.Add(";/n");368 369 if (!w.Word.ToUpper().Equals("END"))370 {371 ErrorList.Add("缺少END标识符！");372 }373 else374 {375 this.C_Source.Add("}/n");376 377 w=this.getNextWord();378 }379 }380 381 }382 383 //"条件"递归程序384 //〈条件〉∷=〈表达式〉〈关系运算符〉〈表达式〉|ODD〈表达式〉385 private void Condition(ref WordTableEntry w)386 {387 if ((w.Word.Equals("+") || w.Word.Equals("-")) || w.WordType==Word_Type.Identifier) 388 {389 this.Expression(ref w);390 this.RelationSymbol(ref w);391 this.Expression(ref w);392 }393 else if (w.Word.ToUpper().Equals("ODD"))394 {395 this.C_Source.Add("(");396 397 w=this.getNextWord();398 this.Expression(ref w);399 400 this.C_Source.Add(")%2==1");401 }402 else403 ErrorList.Add("条件表达式错误！");404 }405 406 //"表达式"递归程序407 //〈表达式〉∷=[+|-]〈项〉{〈加法运算符〉〈项〉} 408 private void Expression(ref WordTableEntry w)409 {410 if (w.Word.Equals("+"))411 {412 this.C_Source.Add("+");413 414 w=this.getNextWord();415 }416 else if (w.Word.Equals("-"))417 {418 this.C_Source.Add("-");419 420 w=this.getNextWord();421 }422 else423 {424 ;425 }426 this.ExpressionItem(ref w);427 while (w.Word.Equals("+") || w.Word.Equals("-"))428 {429 this.AdditiveSymbol(ref w);430 this.ExpressionItem(ref w);431 }432 }433 434 //"项"递归程序435 //〈项〉∷=〈因子〉{〈乘法运算符〉〈因子〉}436 private void ExpressionItem(ref WordTableEntry w)437 {438 this.Gene(ref w);439 while (w.Word.Equals("*") || w.Word.Equals("/"))440 {441 this.MultiplicativeSymbol(ref w);442 this.Gene(ref w);443 }444 }445 446 //"因子"递归程序447 //〈因子〉∷=〈标识符〉|〈无符号整数〉|'('〈表达式〉')'448 private void Gene(ref WordTableEntry w)449 {450 if (w.WordType==Word_Type.Identifier)451 {452 453 this.Identifier(ref w);454 }455 else if (w.WordType==Word_Type.Number)456 {457 458 this.UnsignedNumber(ref w);459 }460 else if (w.Word.Equals("("))461 {462 this.C_Source.Add("(");463 464 w=this.getNextWord();465 this.Expression(ref w);466 if (!w.Word.Equals(")"))467 {468 ErrorList.Add("表达式括号不匹配！");469 }470 else471 {472 this.C_Source.Add(")");473 474 w=this.getNextWord();475 }476 }477 else478 ErrorList.Add("表达式错误！");479 }480 481 //"加法运算符"递归程序482 //〈加法运算符〉∷=+|-483 private void AdditiveSymbol(ref WordTableEntry w)484 {485 if (w.Word.Equals("+") || w.Word.Equals("-"))486 {487 this.C_Source.Add(w.Word);488 489 w=this.getNextWord();490 }491 else492 ErrorList.Add("缺少加减法运算符！");493 }494 495 //"乘法运算符"递归程序496 //〈乘法运算符〉∷=*|/497 private void MultiplicativeSymbol(ref WordTableEntry w)498 {499 if (w.Word.Equals("*") || w.Word.Equals("/"))500 {501 this.C_Source.Add(w.Word);502 503 w=this.getNextWord();504 }505 else506 ErrorList.Add("缺少乘除法运算符！");507 }508 509 //"关系运算符"递归程序510 //〈关系运算符〉∷=#|=|＜|＜=|＞|＞=511 private void RelationSymbol(ref WordTableEntry w)512 {513 if (w.Word.Equals("#") || w.Word.Equals("="))514 {515 this.C_Source.Add(w.Word);516 517 w=this.getNextWord();518 }519 else if (w.Word.Equals("<") || w.Word.Equals("<="))520 {521 this.C_Source.Add(w.Word);522 523 w=this.getNextWord();524 }525 else if (w.Word.Equals(">") || w.Word.Equals(">="))526 {527 this.C_Source.Add(w.Word);528 529 w=this.getNextWord();530 }531 else532 ErrorList.Add("缺少关系运算符！");533 }534 535 //"条件语句"递归程序536 //〈条件语句〉∷=IF〈条件〉THEN〈语句〉537 private void ConditionSentence(ref WordTableEntry w)538 {539 if (w.Word.ToUpper().Equals("IF"))540 {541 this.C_Source.Add("if(");542 543 w=this.getNextWord();544 this.Condition(ref w);545 546 this.C_Source.Add(")/n");547 548 if (w.Word.ToUpper().Equals("THEN"))549 {550 this.C_Source.Add("{/n");551 552 w=this.getNextWord();553 this.Sentence(ref w);554 555 this.C_Source.Add(";/n}/n");556 }557 else558 ErrorList.Add("IF语句缺少THEN子句！");559 }560 else561 ErrorList.Add("条件语句缺少IF！");562 }563 564 //"过程调用语句"递归程序565 //〈过程调用语句〉∷=CALL〈标识符〉566 private void ProcedureCall(ref WordTableEntry w)567 {568 if(w.Word.ToUpper().Equals("CALL"))569 {570 w=this.getNextWord();571 this.Identifier(ref w);572 573 this.C_Source.Add("();/n");574 }575 576 }577 578 //"当型循环语句"递归程序579 //〈当型循环语句〉∷=WHILE〈条件〉DO〈语句〉580 private void WhileSentence(ref WordTableEntry w)581 {582 if (w.Word.ToUpper().Equals("WHILE"))583 {584 this.C_Source.Add("while(");585 586 w=this.getNextWord();587 this.Condition(ref w);588 589 this.C_Source.Add(")/n");590 591 if (w.Word.ToUpper().Equals("DO"))592 {593 this.C_Source.Add("{/n");594 595 w=this.getNextWord();596 this.Sentence(ref w);597 598 this.C_Source.Add(";/n}/n");599 }600 else601 ErrorList.Add("WHILE语句缺少DO子句！");602 }603 else604 ErrorList.Add("循环语句缺少WHILE！");605 }606 607 //"读语句"递归程序608 //〈读语句〉∷=READ'('〈标识符〉{，〈标识符〉}')'609 private void ReadSentence(ref WordTableEntry w)610 {611 if (w.Word.ToUpper().Equals("READ"))612 {613 w=this.getNextWord();614 if (w.Word.Equals("("))615 {616 w=this.getNextWord();617 618 this.C_Source.Add("scanf(/"%d/",&");619 620 this.Identifier(ref w);621 this.C_Source.Add(");/n");622 623 while (w.Word.Equals(","))624 {625 this.C_Source.Add("scanf(/"%d/",&");626 627 w=this.getNextWord();628 this.Identifier(ref w);629 630 this.C_Source.Add(")");631 632 }633 if (!w.Word.Equals(")"))634 {635 ErrorList.Add("READ语句括号不匹配！");636 }637 else638 w=this.getNextWord();639 }640 else641 ErrorList.Add("READ语句缺少左括号！");642 }643 }644 645 //"写语句"递归程序646 //〈写语句〉∷=WRITE'('〈表达式〉{，〈表达式〉}')'647 private void WriteSentence(ref WordTableEntry w)648 {649 if (w.Word.ToUpper().Equals("WRITE"))650 {651 w=this.getNextWord();652 if (w.Word.Equals("("))653 {654 this.C_Source.Add("printf(/"%d//n/",");655 656 w=this.getNextWord();657 this.Expression(ref w);658 659 this.C_Source.Add(");/n");660 661 while (w.Word.Equals(","))662 {663 this.C_Source.Add("printf(/"%d//n/",");664 665 w=this.getNextWord();666 this.Expression(ref w);667 668 this.C_Source.Add(")");669 }670 if (!w.Word.Equals(")"))671 {672 ErrorList.Add("WRITE语句括号不匹配！");673 }674 else675 w=this.getNextWord();676 }677 else678 ErrorList.Add("WRITE语句缺少左括号！");679 }680 }681 682 //***************递归子程序到此结束683 684 //打印错误列表685 private void PrintErrorList()686 {687 System.Console.WriteLine("/n-------------ErrorList-------------");688 if(ErrorList.Count==0)689 System.Console.WriteLine("没有错误发生，编译顺利完成！");690 for(int i=0;i<ErrorList.Count;i++)691 {692 System.Console.WriteLine("[error{0}]:{1}",i,(string)ErrorList[i]);693 }694 }695 696 //将转换好的c语言源程序写如文件697 private void SaveToCFile()698 {699 if(this.PascalFileName.Equals(""))700 {701 System.Console.WriteLine("Unknown output file name!");702 return ;703 }704 705 string temfilename=Regex.Replace(this.PascalFileName,@"./w+$","");706 string OutPutFileName=temfilename+".C";707 708 System.IO.StreamWriter sw=null;//创建输出文件709 710 sw=File.CreateText(OutPutFileName);711 712 sw.WriteLine("/*------------------------------------------------------------");713 sw.WriteLine(" pl0 to C Convertor v0.1 Copyright 2005 yxin1322");714 sw.WriteLine(" C Source File: [{0}]",this.PascalFileName);715 sw.WriteLine(" Create Time:{0}",System.DateTime.Now.ToString());716 sw.WriteLine(" ------------------------------------------------------------*/");717 718 System.Console.WriteLine("/n正在写入文件.../n");719 720 sw.WriteLine("#include <stdio.h>");//添加c文件头部721 sw.WriteLine("main()/n{");722 723 724 for(int i=0;i<this.C_Source.Count;i++)725 {726 sw.Write("{0} ",this.C_Source[i]);727 }728 sw.WriteLine("}");729 sw.Close();730 731 732 System.Console.WriteLine("已经将C源程序写入文件：{0}",OutPutFileName);733 }734 735 public static void Main(string[] args)736 {737 string pl0FileName;738 if(args.Length==0)739 {740 System.Console.WriteLine(" ------------------------------------------------------------");741 System.Console.WriteLine(" <pl0 to C Convertor v0.1> Copyright 2005 yxin1322/n");742 System.Console.WriteLine(" 运行环境：.Net FrameWork 1.1");743 System.Console.WriteLine(" ------------------------------------------------------------");744 745 System.Console.Write("请输入pl0文件的路径及文件名(*.pl0)：");746 pl0FileName=System.Console.ReadLine();747 }748 else749 {750 pl0FileName=args[0];751 }752 753 System.Console.WriteLine(pl0FileName);754 Pascal_to_C p2c=new Pascal_to_C(pl0FileName);755 756 if(p2c.CreateCSourceCode())757 p2c.SaveToCFile();758 759 System.Console.ReadLine();760 }761 }762 }
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