编译原理实验报告 词法分析.doc

编译原理实验一词法分析一、 实验目的通过动手实践，使学生对构造编译系统的基本理论、编译程序的基本结构有更为深入的理解和掌握；使学生掌握编译程序设计的基本方法和步骤；能够设计实现编译系统的重要环节。同时增强编写和调试程序的能力。二、 实验内容及要求对某特定语言A ，构造其词法规则。该语言的单词符号包括：保留字(见左下表)、标识符（字母大小写不敏感）、 整型常数、界符及运算符(见右下表) 。 功能要求如下所示：按单词符号出现的顺序，返回二元组序列，并输出。出现的标识符存放在标识符表，整型常数存放在常数表，并输出这两个表格。如果出现词法错误，报出：错误类型，位置（行，列）。处理段注释（/* */），行注释（/）。有段注释时仍可以正确指出词法错误位置（行，列）。三、 实验过程1、 词法形式化描述使用正则文法进行描述，则可以得到如下的正规式:其中ID表示标识符，NUM表示整型常量，RES表示保留字，DEL表示界符，OPR表示运算符。 A(ID | NUM | RES | DEL | OPR) *IDletter(letter | didit)*NUMdigit digit*lettera | | z | A | | Zdigit 0 | | 9RES program | begin | end | var | int | and | or | not | if | then | else | while | doDEL( | ) | . | ; | ,OPR+ | * | := | | = | = | 如果关键字、标识符和常数之间没有确定的算符或界符作间隔，则至少用一个空格作间隔。空格由空白、制表符和换行符组成。2、 单词种别定义；A语言中的单词符号及其对应的种别编码如下表所示：单词符号种别编码单词符号种别编码program1+16begin2*17end3(18var4)19int5,20and6.21or7:=22not8;23if924then10=27do13=28标识符1429整型常量15-303、 状态转换图；语言A的词法分析的状态转换图如下所示：空格符，制表符 或回车符 字母或数字非字母或数字2字母01 数字非数字3+4数字587*633()2224非=其他-142513812):9,.=101115;/16=28/*2627其他23=171819非=index = 0; ctable-index = 0; itail = itable; ctail = ctable; etail = etable; itable-next = NULL; ctable-next = NULL; etable-next = NULL; fseek(pf, 0, SEEK_END); nLen = ftell(pf); rewind(pf); pchBuf = (char*) malloc(sizeof(char)*nLen+1); nLen = fread(pchBuf, sizeof(char), nLen, pf); pchBufnLen = 0; ch = pchBuf; fclose(pf); while(*ch) curBinary = lexicalAnalyze(); if(curBinary) if(curBinary-type = 14 | curBinary-type = 15) fprintf(pf1,(%d,%d)n,curBinary-type,curBinary-property); else if(curBinary-type 0) fprintf(pf1,(%d,_)n,curBinary-type);else if(curBinary-type = -1) if(*ch = 0) break; while(*ch != n & *ch != t & *ch != & !(*ch = / & *(ch+1) = /) & !(*ch = / & *(ch+1) = *) ) GetChar(); free(curBinary); /打印标识符表、常数表和错误表 fprintf(pf1,nIdentifier Table:n); itail = itable-next; while(itail) fprintf(pf1,%d %sn,itail-index, itail-name); itail = itail-next; fprintf(nConstant Table:n); ctail = ctable-next; while(ctail) printf(%d %dn,ctail-index, ctail-value); ctail = ctail-next; printf(n%d error（s）:n ,errors); etail = etable-next; while(etail) printf(line:%d row:%d %sn,etail-line, etail-row, etail-describe); etail = etail-next; fclose(pf1); printf(succeed); getch();struct binary *lexicalAnalyze() struct binary *newBinary = (struct binary*)malloc(sizeof(struct binary); int annotation; int property; strToken0 = 0; curChar = 0; GetBC(); if(*ch = 0) /是否到达数据结束 free(newBinary); return NULL; if(isLetter() /是否标识符 while(isLetter() | isDigit() if(ConCat() GetChar(); else errProc(1); newBinary-type = -1; return newBinary; property = Reserved(); if(property) /是否保留字 newBinary-type = property; return newBinary; property = isId(); if(property) newBinary-type = 14; newBinary-property = property; return newBinary; else newBinary-type = 14; newBinary-property = insertId(); return newBinary; else if(isDigit() /是否常数 while(isDigit() ConCat(); GetChar(); property = isConst(); if(property) newBinary-type = 15; newBinary-property = property; return newBinary; else newBinary-type = 15; newBinary-property = insertConst(); return newBinary; else switch(*ch) case +:newBinary-type = 16;break; case *:newBinary-type = 17;break; case (:newBinary-type = 18;break; case ):newBinary-type = 19;break; case ,:newBinary-type = 20;break; case .:newBinary-type = 21;break; case ;:newBinary-type = 23;break; case -:newBinary-type = 30;break; case : GetChar(); if(*ch = =) newBinary-type = 19; break; else ch-; row-; errProc(2); newBinary-type = -1; GetChar(); return newBinary; case : GetChar(); if(*ch = =) newBinary-type = 27; else newBinary-type = 24; ch-; row-; break; case type = 28; else if(*ch = ) newBinary-type = 29; else newBinary-type = 25; ch-; row-; break; case =:newBinary-type = 26;break; case /: annotation = isAnnotation(); if(annotation) if(annotation = -1) errProc(3); newBinary-type = -1; return newBinary; free(newBinary); return NULL; else ch-; row-; errProc(2); newBinary-type = -1; GetChar(); return newBinary; default: errProc(2); newBinary-type = -1; GetChar(); return newBinary; GetChar(); return newBinary; void GetBC() if(*ch = n) line+; row = 0; while(*ch = | *ch = t | *ch = n) GetChar(); if(*ch = n) line+; row = 0; void GetChar() ch+; if(*ch = t) row += 4; else row+;int ConCat() if(curChar = A & *ch index; struct identifier *newId = (struct identifier*)malloc(sizeof(struct identifier); itail-next = newId; itail = newId; strcpy(itail-name,strToken); itail-next = NULL; itail-index = index + 1; curChar = 0; strTokencurChar = 0; return index+1;int insertConst() int index = ctail-index; struct constant *newConst = (struct constant*)malloc(sizeof(struct constant); ctail-next = newConst; ctail = newConst; ctail-value = atoi(strToken); ctail-next = NULL; ctail-index = index + 1; curChar = 0; strTokencurChar = 0; return index+1;int Reserved() int i; for(i=0;inext; while(curId) if(strcmp(curId-name,strToken) = 0) return curId-index; else curId = curId-next; return 0;int isConst() struct constant *curId = ctable-next; while(curId) if(curId-value = atoi(strToken) return curId-index; else curId = curId-next; return 0; int isAnnotation() GetChar(); if(*ch = / | *ch = *) if(*ch = /) while(*ch & *ch != n) GetChar(); return 1; else while(*ch & !(*ch = * & *(ch+1) = /) GetChar(); GetBC(); if(*ch) GetChar(); GetChar(); return 1; else return -1; else return 0;void errProc(int type)struct err *newErr = (struct err*)malloc(sizeof(struct err);errors+; etail-next = newErr; newErr-next = NULL; newErr-line = line; newErr-row = row; switch(type) c