实验三-语义分析-实习报告

实验三 语义分析一、实习目的通过上机实习，加深对语法制时翻译原理的理解，掌握将语法分析所识别的语法成分变换为中间代码的语义翻译方法。二、实习要求采用递归下降语法制导翻译法对算术表达式、赋值语句、条件语句、循环语句进行语义分析生成四元式序列。三、实习过程实习代码;/* * JavaCC file */ options JDK_VERSION = 1.5; static=false;PARSER_BEGIN(whileParse)package whileparse;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.util.ArrayList;public class whileParse public int count=0; /*四元式标号*/ public static ArrayList sysList = new ArrayList(); public int ncount=0; /*临时变量下标*/ public static void main(String args) throws ParseException FileInputStream fileStream;try fileStream = new FileInputStream(data/test.c); whileParse parser = new whileParse(fileStream); System.out.println(Reading from standard input.); System.out.println(Enter c programe only main() with only while(); :); try switch (parser.start() case 0: System.out.println(OK.); break; case 1: System.out.println(Goodbye.); break; default: break; for(int i = 0; isysList.size(); i+) System.out.println(sysList.get(i); catch (Exception e) System.out.println(NOK.); System.out.println(e.getMessage(); parser.ReInit(System.in); catch (Error e) System.out.println(Oops.); System.out.println(e.getMessage(); catch (FileNotFoundException e1) e1.printStackTrace(); PARSER_END(whileParse) SKIP : |r|t|n| TOKEN : /* OPERATORS */|TOKEN : CONSTANT: ( )+ | TOKEN: | | | | | |TOKEN:| LOWER:| =| LOWERW:TOKEN: | | | | | int start() : Procedure() return 0; | return 1; /*处理主程序*/void Procedure(): (Content()* void Content():WhileStatement()|IfStatement()void WhileStatement(): Token node; int j1; int next; Sys newsys; next=count+1; Condition() count+; j1=count; newsys = new Sys(count+,J,_, _, j1+#); sysList.add(newsys); (WhileStatement()|IfStatement()*)* count+; newsys = new Sys(count+,J,_, _, next+); sysList.add(newsys); EditSys.huitian(sysList, j1+#, count+1+); void IfStatement(): Token node; int j1; int next; Sys newsys; next=count+1; Condition() count+; j1=count; newsys = new Sys(count+,J,_, _, j1+#); sysList.add(newsys); (IfStatement()|WhileStatement()*)* count+; newsys = new Sys(count+,J,_, _, next+); sysList.add(newsys); EditSys.huitian(sysList, j1+#, count+1+); String Expression() : String first; String middle; String temp=; Sys newsys; first=Term() temp=first; ( middle=Term() count+; temp=T+ncount; ncount+; newsys = new Sys(count+,+,first,middle,temp); sysList.add(newsys); first = temp; /first=Integer.parseInt(first)+Integer.parseInt(middle)+; | middle=Term() count+; temp=T+ncount; ncount+; newsys = new Sys(count+,-,first,middle,temp); sysList.add(newsys); first = temp; /first=Integer.parseInt(first)-Integer.parseInt(middle)+; )* return temp; /return first; String Term() : String first; String middle; String temp=; Sys newsys; first=unary() temp=first; ( ( middle= unary() count+; temp=T+ncount; ncount+; newsys = new Sys(count+,*,first,middle,temp); sysList.add(newsys); first = temp; /first=Integer.parseInt(first)*Integer.parseInt(middle)+; | middle=unary() count+; temp=T+ncount; ncount+; newsys = new Sys(count+,/,first,middle,temp); sysList.add(newsys); first = temp; /first=Integer.parseInt(first)/Integer.parseInt(middle)+; ) )* return temp; /return first; String unary() : String str; / str= element()return -Double.parseDouble(str)+; str= element()return str;String element() : String str;Token node; node=return node.image;| str=Expression()return str;int Condition(): Token node; int next; String first; String middle; Sys newsys; first=Expression()(node= middle=Expression() count+; next=count+1; newsys = new Sys(count+,j middle=Expression() count+; next=count+1; newsys = new Sys(count+,j,first,middle,next+1+); sysList.add(newsys); | node= middle=Expression() count+; next=count+1; newsys = new Sys(count+,j=,first,middle,next+1+); sysList.add(newsys); | node= middle=Expression() count+; next=count+1; newsys = new Sys(count+,j=,first,middle,next+1+); sysLis