semantic.c

#include <stdio.h>
#include <ctype.h>
#include <conio.h>
#define maxvartablep 500/*定义符号表达式*/
int TESTparse();
int program();
int compound_stat();
int statement();
int expression_stat();
int expression();
int bool_expr();
int additive_expr();
int term();
int factor();
int if_stat();
int while_stat();
int for_stat();
int write_stat();
int read_stat();
int declaration_stat();
int declaration_list();
int statement_list();
int compound_list();
int name_def(char *name);
char token[20],token1[40];/*token保存单词符号，token1保存单词组*/
extern char Scanout[300],Codeout[300];/*保存词法分析输出文件名*/
FILE *fp,*fout;/*用于指向输入输出文件的指针*/
struct /*定义符号表结构*/
{
 char name[8];
 int address;
}vartable[maxvartablep];/*改符号表最多容纳maxvartablep个记录*/
int vartablep=0,labelp=0,datap=0;/*插入符号表动作@name-def!n,t的程序如下*/
int name_def(char *name)
{
 int i,es=0;
 if(vartablep>=maxvartablep) return(21);
 for(i=vartablep-1;i>=0;i--)/*查符号表*/
 {
  if(strcmp(vartable[i],name,name)==0)
  {
   es=22;/*22表示变量重复声明*/
   break;
  }
 }
 if(es>0) return(es);
 strcpy(vartable[vartablep],name,name);
 vartable[vartablep].address=datap;
 printf("@\n");
 printf("  %s  %d\n",vartable[vartablep].name,vartable[vartablep].address);
 printf("@\n");
 datap++;/*分配一个单元，数据区指针加1*/
 vartablep++;
 return(es);
}
/*查询符号表返回地址*/
int lookup(char *name,int *paddress)
{
 int i,es=0;
 for(i=0;i<vartablep;i++)
 {
  if(strcmp(vartable[i],name,name)==0)
  {
   *paddress=vartable[i].address;
   return(es);
  }
 }
 es=23;/*变量没有声明*/
 return(es);
}
/*语法、语义分析及代码生成程序*/
int TESTparse()
{
 int es=0;
 if((fp=fopen(Scanout,"r"))==NULL)
 {
  printf("\n open%serror!\n",Scanout);
  es=10;
  return(es);
 }
 printf("qing shu ru mu biao wen jian(bao kuo lu jing):");
 scanf("%s",Codeout);
 if((fout=fopen(Codeout,"w"))==NULL)
 {
  printf("\n create%serror!\n",Codeout);
  es=10;
  return(es);
 }
 if(es==0) es=program();
 printf("==yu fa\yu yi fen xi ji dai ma sheng cheng cheng xu jie guo==\n");/*语法、语义分析及代码生成程序结果*/
 switch(es)
 {
  case 0:printf("yu fa\yu yi fen xi cheng gong bing chou xiang ji hui bian sheng cheng dai ma!\n");break;/*语法、语义分析成功并抽象机汇编生成代码！*/
  case 10:printf("open text%serror!\n",Scanout);break;
  case 1:printf("lack of{!\n");break;
  case 2:printf("lack of}!\n");break;
  case 3:printf("lack of biao shi fu!\n");break;
  case 4:printf("lack of fen hao!\n");break;
  case 5:printf("lack of(!\n");break;
  case 6:printf("lack of)!\n");break;
  case 7:printf("lack of cao zuo shu!\n");break;
  case 21:printf("fu hao biao yi chu!\n");break;/*符号表溢出*/
  case 22:printf("bian liang chong fu ding yi!\n");break;/*变量重复定义*/
  case 23:printf("bian liang wei sheng ming!\n");break;/*变量未声明*/
 }
 fclose(fp);
 fclose(fout);
 return(es);
}
/*<程序>::={<声明序列><语句序列>}*/
/*program::={<declaration_list><statement_list>}*/
int program()
{
 int es=0,i;
 fscanf(fp,"%s%s\n",token,token1);
 printf("%s%s\n",token,token1);
 if(strcmp(token,"{"))/*判断是否'{'*/
 {
  es=1;
  return(es);
 }
 fscanf(fp,"%s%s\n",&token,&token1);
 printf("%s%s\n",token,token1);
 es=declaration_list();
 if(es>0) return(es);
 printf("  fu hao biao\n");
 printf("  name  address");
 for(i=0;i<vartablep;i++)
  printf("  %s  %d\n",vartable[i].name,vartable[i].address);
 es=statement_list();
 if(es>0) return(es);/*判断是否'}'*/
 if(strcmp(token,"}"))
 {
  es=2;
  return(es);
 }
 fprintf(fout,"  STOP\n");/*生产停止指令*/
 return(es);
}
/*<声明序列>::=<声明序列><声明语句>|<声明语句>*/
/*<declaration_list>::=<declaration_list><declaration_stat>|<declaration_stat>*/
/*改成<declaration_list>::={<declaration_stat>}*/
int declaration_list()
{
 int es=0;
 while(strcmp(token,"int")==0)
 {
  es=declaration_stat();
  if(es>0) return(es);
 }
 return(es);
}
/*<声明语句>::=int<变量>*/
/*<declaration_stat>!vartablep,datap,codep->int ID!n@name-def!n,t;<>*/
int declaration_stat()
{
 int es=0;
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,"ID")) return(es=3);/*不是标识符*/
 es=name_def(token1);/*插入标识符*/
 if(es>0) return(es);
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,";")) return(es=4);
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 return(es);
}
/*<语句序列>::=<语句序列><语句>|<语句>*/
/*<statement_list>::=<statement_list><statement>|<statement>*/
/*改成<statement_list>::={<statement>}*/
int statement_list()
{
 int es=0;
 while(strcmp(token,"}"))
 {
  es=statement();
  if(es>0) return(es);
 }
 return(es);
}
/*<语句>::=<if语句>|<while语句>|<for语句>|<read语句>|<write语句>|<复合语句>|<表达式语句>*/
/*<statement>::=<if_stat>|<while_stat>|<for_stat>|<compound_stat>|<expression_stat>*/
int statement()
{
 int es=0;
 if(es==0&&strcmp(token,"if")==0) es=if_stat();
 if(es==0&&strcmp(token,"while")==0) es=while_stat();
 if(es==0&&strcmp(token,"for")==0) es=for_stat();
 /*可在此处添加do语句调用*/
 if(es==0&&strcmp(token,"read")==0) es=read_stat();
 if(es==0&&strcmp(token,"write")==0) es=write_stat();
 if(es==0&&strcmp(token,"{")==0) es=compound_stat();/*复合语句*/
 if(es==0&&strcmp(token,"ID")==0||strcmp(token,"NUM")==0) es=expression_stat();/*表达式语句*/
 return(es);
}
/*<if语句>::=if(<表达式>)<语句>[else<语句>]*/
/*<if_stat>::=if(<expr>)<statement>[else<statement>]*/
/*if(<表达式>)@BRF!label1<语句>@BR!label2@SETlabel!label1[else<语句>]@SETlabel!label2
if(<expression>)@BRF!label1<statement>@BR!label2@SETlabel!label1[else<statement>]@SETlabel!label2
其中动作符号的含义如下：
@BRF!label1:输出BRFlabel1
@BR!label2:输出BRlabel2
@SETlabel!label1:设置标号label1
@SETlabel!label2:设置标号label2*/
int if_stat()
{
 int es=0,label1,label2;/*if*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,"(")) return(es=5);/*少左括号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=expression();
 if(es>0) return(es);
 if(strcmp(token,")")) return(es=6);/*少右括号*/
 label1=labelp++;/*用label1记住条件为假时要转向的标号*/
 fprintf(fout,"  BRF LABEL%d\n",label1);/*输出假转移指令*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=statement();
 if(es>0) return(es);
 label2=labelp++;/*用label2记住要转向的标号*/
 fprintf(fout,"  BR LABEL%d\n",label2);/*输出无条件转移指令*/
 fprintf(fout,"LABEL%d:\n",label1);/*设置label1记住的标号*/
 if(strcmp(token,"else")==0)/*else部分处理*/
 {
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  es=statement();
  if(es>0) return(es);
 }
 fprintf(fout,"LABEL%d:\n",label2);/*设置label2记住的标号*/
 return(es);
}
/*<while语句>::=while(<表达式>)<语句>*/
/*<while_stat>::=while(<expr>)<statement>*/
/*<while_stat>::=while@SETlabel!label1(<expression>)@BRF!label2<statement>@BR!label@SETlabel!label2
动作解释：
@SETlabel!label1:设置标号label1
@BRF!label2:输出BRFlabel2
@BR!label1:输出BRlabel1
@SETlabel!label2:设置标号label2*/
int while_stat()
{
 int es=0,label1,label2;
 label1=labelp++;
 fprintf(fout,"LABEL%d:\n",label1);/*设置label1记住的标号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,"(")) return(es=5);/*少左括号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=expression();
 if(es>0) return(es);
 if(strcmp(token,")")) return(es=6);/*少右括号*/
 label2=labelp++;
 fprintf(fout,"  BRF LABEL%d\n",label2);/*输出无条件转移指令*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=statement();
 if(es>0) return(es);
 fprintf(fout,"  BR LABEL%d\n",label1);/*输出假转移指令*/
 fprintf(fout,"LABEL%d:\n",label2);/*设置label2记住的标号*/
 return(es);
}
/*<for_stat>::=for(<expr>,<expr>,<expr>)<statement>*/
/*<for_stat>::=for(<expression>;
 @SETlabel!label1<expression>@BRF!label2@BR!label3;
 @SETlabel!label4<expression>@BR!label)
 @SETlabel!label3<statement>@BR!label4@SETlabel!label2
动作解释：
1,@SETlabel!label1:设置标号label1
2,@BRF!label2:输出BRFlabel2
3,@BR!label3:输出BRlabel3
4,@SETlabel!label4:设置标号label4
5,@BR!label1:输出BRlabel1
6,@SETlabel!label3:设置标号label3
7,@BR!label4:输出BRlabel4
8,@SETlabel!label2:设置标号label2*/
int for_stat()
{
 int es=0,label1,label2,label3,label4;
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,"(")) return(es=5);/*少左括号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=expression();
 if(es>0) return(es);
 if(strcmp(token,";")) return(es=4);/*少分号*/
 label1=labelp++;
 fprintf(fout,"LABEL%d:\n",label1);/*设置label1标号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=expression();
 if(es>0) return(es);
 label2=labelp++;
 fprintf(fout,"  BRF LABEL%d\n",label2);/*输出无条件转移指令*/
 label3=labelp++;
 fprintf(fout,"  BR LABEL%d\n",label3);/*输出无条件转移指令*/
 if(strcmp(token,";")) return(es=4);/*少分号*/
 label4=labelp++;
 fprintf(fout,"LABEL%d:\n",label4);/*设置label4标号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=expression();
 if(es>0) return(es);
 fprintf(fout,"  BR LABEL%d\n",label1);/*输出无条件转移指令*/
 if(strcmp(token,")")) return(es=6);/*少右括号*/
 fprintf(fout,"LABEL%d:\n",label3);/*设置label3标号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=statement();
 if(es>0) return(es);
 fprintf(fout,"  BR LABEL%d\n",label4);/*输出无条件转移指令*/
 fprintf(fout,"LABEL%d:\n",label2);/*设置label2标号*/
 return(es);
}
/*<write_stat>::=write<expression>*/
/*<write_stat>::=write<expression>@OUT*/
/*动作解释：
@OUT:输出OUT*/
int write_stat()
{
 int es=0;
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=expression();
 if(es>0) return(es);
 if(strcmp(token,";")) return(es=4);/*少分号*/
 fprintf(fout,"   OUT\n");/*输出指令*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 return(es);
}
/*<read_stat>::=read ID*/
/*<read_stat>::=read ID!n LOOK!n!d@IN@STI!d*/
/*动作解释
@LOOK!n!d查符号表n，给出变量地址d；没有，变量没定义
@IN:输出IN
@STI!d:输出指令代码STI d*/
int read_stat()
{
 int es=0,address;
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,"ID")) return(es=3);/*少标识符*/
 es=lookup(token1,&address);
 if(es>0) return(es);
 fprintf(fout,"  IN  %d\n",address);/*输入指令*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 if(strcmp(token,"；")) return(es=4);/*少分号*/
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 return(es);
}
/*<compound_stat>::={<statement_list>}*/
int compound_stat()
{
 int es=0;
 fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 es=statement_list();
 return(es);
}
/*<expression_stat>::=<expression>*/
int expression_stat()
{
 int es=0;
 if(strcmp(token,";")==0)
 {
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  return(es);
 }
 es=expression();
 if(es>0) return(es);
 if(strcmp(token,";")==0)
 {
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  return(es);
 }
 else
 {
  es=4;
  return(es);/*少分号*/
 }
}
/*<表达式>::=<标识符>=<布尔表达式>|<布尔表达式>*/
int expression()
{
 int es=0,fileadd;
 char token2[20],token3[30];
 if(strcmp(token,"ID")==0)
 {
  fileadd=ftell(fp);/*记住当前文件位置*/
  fscanf(fp,"%s%s\n",&token2,&token3);printf("%s%s\n",token2,token3);
  if(strcmp(token2,"=")==0)/*'='*/
  {
   int address;
   es=lookup(token1,&address);
   if(es>0) return(es);
   fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
   es=bool_expr();
   if(es>0) return(es);
   fprintf(fout,"  STO%d\n",address);
  }
  else
  {
   fseek(fp,fileadd,0);/*若非'='则文件指针回到'='前的标识符*/
   printf("%s%s\n",token,token1);
   es=bool_expr();
   if(es>0) return(es);
  }
 }
 return(es);
}
/*<bool_expr>::=<additive_expr>|<additive_expr>(>|<|>=|<=|==|!=)<additive_expr>*/
/*<bool_expr>::=<additive_expr>
|<additive_expr>><additive_expr>@GT
|<additive_expr><<additive_expr>@LES
|<additive_expr>>=<additive_expr>@GE
|<additive_expr><=<additive_expr>@LE
|<additive_expr>==<additive_expr>@EQ
|<additive_expr>!=<additive_expr>@NOTEQ*/
int bool_expr()
{
 int es=0;
 es=additive_expr();
 if(es>0) return(es);
 if(strcmp(token,">")==0||strcmp(token,">=")==0||strcmp(token,"<")==0||strcmp(token,"<=")==0||strcmp(token,"==")==0||strcmp(token,"!=")==0)
 {
  char token2[20];
  strcpy(token2,token);
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  es=additive_expr();
  if(es>0) return(es);
  if(strcmp(token2,">")==0) fprintf(fout,"  GT\n");
  if(strcmp(token2,">=")==0) fprintf(fout,"  GE\n");
  if(strcmp(token2,"<")==0) fprintf(fout,"  LES\n");
  if(strcmp(token2,"<=")==0) fprintf(fout,"  LE\n");
  if(strcmp(token2,"==")==0) fprintf(fout,"  EQ\n");
  if(strcmp(token2,"!=")==0) fprintf(fout,"  NOTEQ\n");
 }
 return(es);
}
/*<additive_expr>::=<term>{(+|-)<term>}*/
/*<additive_expr>::=<term>{(+<term>@ADD|-<term>@SUB)}*/
int additive_expr()
{
 int es=0;
 es=term();
 if(es>0) return(es);
 while(strcmp(token,"+")==0||strcmp(token,"-")==0)
 {
  char token2[20];
  strcpy(token2,token);
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  es=term();
  if(es>0) return(es);
  if(strcmp(token2,"+")==0) fprintf(fout,"  ADD\n");
  if(strcmp(token2,"-")==0) fprintf(fout,"  SUB\n");
 }
 return(es);
}
/*<term>::=<factor>{(*|/)<factor>}*/
/*<term>::=<factor>{(*<factor>@MULT|/<factor>@DIV)}*/
int term()
{
 int es=0;
 es=factor();
 if(es>0) return(es);
 while(strcmp(token,"*")==0||strcmp(token,"/")==0)
 {
  char token2[20];
  strcpy(token2,token);
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  es=factor();
  if(es>0) return(es);
  if(strcmp(token2,"*")==0) fprintf(fout,"  MULT\n");
  if(strcmp(token2,"/")==0) fprintf(fout,"  DIV\n");
 }
 return(es);
}
/*<factor>::=(<additive_expr>)|ID|NUM*/
/*<factor>::=(<expression>)|ID!n@LOOK!n!d@LOAD!d|NUM!i@LOAD!i*/
int factor()
{
 int es=0;
 if(strcmp(token,"(")==0)
 {
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
  es=expression();
  if(es>0) return(es);
  if(strcmp(token,")")) return(es=6);/*少右括号*/
  fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
 }
 else
 {
  if(strcmp(token,"ID")==0)
  {
   int address;
   es=lookup(token1,&address);/*查符号表，获取变量地址*/
   if(es>0) return(es);/*变量没声明*/
   fprintf(fout,"  LOAD%d\n",address);
   fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
   return(es);
  }
  if(strcmp(token,"NUM")==0)
  {
   fprintf(fout,"  LOADI%d\n",token1);
   fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);
   return(es);
  }
  else
  {
   es=7;/*缺少操作数*/
   return(es);
  }
 }
 return(es);
}