compiler.c

一个编译器的例子,基于c语言,在linux下开发 现在了简单的c语言例子

			fprintf(file, "\t%s\n", "fucompp");
			fprintf(file, "\t%s\n", "fnstsw  %ax");
			fprintf(file, "\t%s\n", "testb $69, %ah");
			fprintf(file, "\t%s%d\n", "je TRUElabel", booll);
		}
		if(strcmp(tree->value, ">=")==0){
			//fprintf(file, "\t%s\n", "fxch");
			fprintf(file, "\t%s\n", "fucompp");
			fprintf(file, "\t%s\n", "fnstsw  %ax");
			fprintf(file, "\t%s\n", "testb $5, %ah");
			fprintf(file, "\t%s%d\n", "je TRUElabel", booll);
		}
		if(strcmp(tree->value, "<")==0){
			fprintf(file, "\t%s\n", "fxch");
			fprintf(file, "\t%s\n", "fucompp");
			fprintf(file, "\t%s\n", "fnstsw  %ax");
			fprintf(file, "\t%s\n", "testb $69, %ah");
			fprintf(file, "\t%s%d\n", "je TRUElabel", booll);
		}
		if(strcmp(tree->value, "<=")==0){
			fprintf(file, "\t%s\n", "fxch");
			fprintf(file, "\t%s\n", "fucompp");
			fprintf(file, "\t%s\n", "fnstsw  %ax");
			fprintf(file, "\t%s\n", "testb $5, %ah");
			fprintf(file, "\t%s%d\n", "je TRUElabel", booll);
		}
		if(strcmp(tree->value, "==")==0){
			//fprintf(file, "\t%s\n", "fxch");
			fprintf(file, "\t%s\n", "fucompp");
			fprintf(file, "\t%s\n", "fnstsw  %ax");
			fprintf(file, "\t%s\n", "andb $69, %ah");
			fprintf(file, "\t%s\n", "cmpb $64, %ah");
			fprintf(file, "\t%s%d\n", "je TRUElabel", booll);
		}               
		if(strcmp(tree->value, "!=")==0){
			//fprintf(file, "\t%s\n", "fxch");
			fprintf(file, "\t%s\n", "fucompp");
			fprintf(file, "\t%s\n", "fnstsw  %ax");
			fprintf(file, "\t%s\n", "andb $69, %ah");
			fprintf(file, "\t%s\n", "xorb $64, %ah");
			fprintf(file, "\t%s%d\n", "jne TRUElabel", booll);
		} 
		fprintf(file, "\t%s\n","movl $0, %eax");
		fprintf(file, "\t%s%d\n", "jmp ENDBOOL", booll);
		fprintf(file, "%s%d%s\n", "TRUElabel", booll,":");                   /* true label  */
		fprintf(file, "\t%s\n", "movl $1, %eax");
		fprintf(file, "%s%d%s\n",  "ENDBOOL", booll,":");                 /*  end label */
       } 
}


void gen_if(FILE *file, symnode *tree)
{
     if(tree==NULL) return;
     int ifl;
     gen_assign(file, tree->sibling->next);
     //fprintf(file, "\t%s\n","popl %eax");
     
     fprintf(file, "\t%s\n","cmpl $0, (%esp)");
     ifl=IFlabel;
   
     if(strcmp(tree->value,"ifelse")==0) 
     	fprintf(file, "\t%s%d\n", "je ELSElabel", ifl);
     else
     	fprintf(file, "\t%s%d\n", "je ENDIFlabel", ifl);
     IFlabel++;
     
     gen_func_content(file, tree->sibling->sibling->next);
         
     if(strcmp(tree->value,"ifelse")==0){
        fprintf(file, "\t%s%d\n", "jmp ENDIFlabel",ifl);
        fprintf(file, "%s%d:\n", "ELSElabel",ifl);        
	gen_func_content(file, tree->sibling->sibling->sibling->next);
     
        //fprintf(file, "\t%s%d\n", "jmp ENDIFlabel",ifl); 
     }
     fprintf(file, "%s%d:\n", "ENDIFlabel",ifl);
     
     
}

void gen_switch(FILE *file, symnode *tree)
{
    if(tree==NULL) return;
    int switchl;
    symnode caselist;
    switchl=SWITCHlabel;
    SWITCHlabel++;
    CASElabel=0;
    gen_assign(file, tree->sibling->next);  // the returned value is at top of stack
    fprintf(file, "\t%s\n", "popl %eax");
    gen_case_condition(file, tree->sibling->sibling->next);
    
    CASElabel=0;
    gen_case(file, tree->sibling->sibling->next);
    fprintf(file, "%s%d:\n", "ENDSWITCHlabel",switchl);    
    return;
}

void gen_case_condition(FILE *file, symnode *tree)
{
   if(tree==NULL) return;
   gen_case_condition(file, tree->next);
   gen_case_condition(file, tree->sibling);
  
   if(strcmp(tree->name, "case")==0){
          int casel;
	  casel = CASElabel;
          fprintf(file,"\t%s%s, %s\n","cmpl $", tree->sibling->next->value, "%eax");
	  fprintf(file, "\t%s%d%s%d\n", "je S", SWITCHlabel-1, "CASElabel",casel);
	  CASElabel=casel;
	  CASElabel++;
	  return;
   }
   if(strcmp(tree->name, "default")==0){
          fprintf(file, "\t%s%d\n", "jmp DEFAULT", SWITCHlabel-1);
	  return;
   }
}

void gen_case(FILE *file, symnode *tree)
{
    if (tree==NULL) return;
    gen_case(file, tree->next);
    gen_case(file, tree->sibling);
    
    if(strcmp(tree->name, "break")==0){
        gen_break(file);
        return;
    }
    
    if(strcmp(tree->name, "case")==0){
        int casel;
	casel = CASElabel;
        fprintf(file, "%s%d%s%d:\n", "S", SWITCHlabel-1, "CASElabel", casel);
	gen_func_content(file, tree->sibling->sibling->next);
	CASElabel=casel;
	CASElabel++;
        return;
    }
    
    if(strcmp(tree->name, "default")==0){
        fprintf(file, "%s%d:\n", "DEFAULT", SWITCHlabel-1);
	gen_func_content(file, tree->sibling->next);
        return;
    }
}

void gen_for(FILE *file, symnode *tree)
{
    if(tree==NULL) return;
    int forl;
    forl=FORlabel;
    FORlabel++;
    if(tree->sibling->next!=NULL) 
             gen_assign(file, tree->sibling->next);
     fprintf(file, "%s%d:\n", "FORlabel",forl);     
    if(tree->sibling->sibling->next!=NULL){ 
             gen_assign(file, tree->sibling->sibling->next); 
	     fprintf(file, "\t%s\n","popl %eax");
             fprintf(file, "\t%s\n","cmpl $0, %eax");   
             fprintf(file, "\t%s%d\n", "je ENDFORlabel", forl); 
    }
     if(strcmp(tree->sibling->sibling->sibling->name, "stmt")==0){
           gen_func_content(file, tree->sibling->sibling->sibling->next);
     }else
           gen_func_content(file, tree->sibling->sibling->sibling->sibling->next);
    fprintf(file, "%s%d:\n", "FOR_COUNT", forl); 
    if(strcmp(tree->sibling->sibling->sibling->name, "exp")==0)
           gen_assign(file, tree->sibling->sibling->sibling->next);

    fprintf(file, "\t%s%d\n", "jmp FORlabel", forl);
    fprintf(file, "%s%d:\n", "ENDFORlabel", forl);
    return;
}

void gen_while(FILE *file, symnode *tree)
{
     if(tree==NULL) return;
     int whilel;
     whilel=WHILElabel;

     WHILElabel++;

     fprintf(file, "%s%d:\n", "WHILElabel",whilel);
     
     gen_assign(file, tree->sibling->next);
     fprintf(file, "\t%s\n","popl %eax");
     fprintf(file, "\t%s\n","cmpl $0, %eax");   
     fprintf(file, "\t%s%d\n", "je ENDWHILElabel", whilel);   
     
     gen_func_content(file, tree->sibling->sibling->next);
     
     fprintf(file, "\t%s%d\n", "jmp WHILElabel",whilel);
     fprintf(file, "%s%d:\n", "ENDWHILElabel",whilel);     
}

void gen_dowhile(FILE *file, symnode *tree)
{
     if(tree==NULL) return;
     int dol;
     dol=DOlabel;

     DOlabel++;
     
     fprintf(file, "%s%d:\n", "DOlabel",dol);
     gen_func_content(file, tree->sibling->next);
     
     
     gen_assign(file, tree->sibling->sibling->next);
     fprintf(file, "\t%s\n","popl %eax");
     fprintf(file, "\t%s\n","cmpl $0, %eax");   
     fprintf(file, "\t%s%d\n", "jne DOlabel", dol);   
     fprintf(file, "%s%d:\n", "ENDDOlabel",dol);
}

void gen_break(FILE *file)
{
     switch (loopType){
     
        case 1: 
             fprintf(file, "\t%s%d\n", "jmp ENDWHILElabel",WHILElabel-1);
	     break;
	case 2:
             fprintf(file, "\t%s%d\n", "jmp ENDDOlabel",DOlabel-1);
	     break;
	case 3:
             fprintf(file, "\t%s%d\n", "jmp ENDFORlabel",FORlabel-1);
       	     break;
	case 4:
             fprintf(file, "\t%s%d\n", "jmp ENDSWITCHlabel",SWITCHlabel-1);
       	     break;	     
	default:
	     printf("--compiling error: \"break\" only used within loops(for, while) or \"switch\"\n");	
	     exit(1);	  
     
     }
 
}

void gen_continue(FILE *file)
{
     switch (loopType){
     
        case 1: 
             fprintf(file, "\t%s%d\n", "jmp WHILElabel",WHILElabel-1);
	     break;
	case 2:
             fprintf(file, "\t%s%d\n", "jmp DOlabel",DOlabel-1);
	     break;
	case 3:
             fprintf(file, "\t%s%d\n", "jmp FOR_COUNT",FORlabel-1);
       	     break;
	default:
	     printf("--compiling error: \"continue\" only used with loops(for, while)\n");
	     exit(1);	  
     
     }
 
}
      
void gen_println(FILE *file, symnode *tree)
{
     int  type;
     if(tree == NULL) return;
     //printf("%s\n",tree->name);

     if(strcmp(tree->name, "offset")==0){
         gen_OffsetIDAddress( file, tree);
	 type=tree->sibling->symTab->type;
	 //printf("type: %d\n", type);
	 if(type==5){
	            int size;
		    type = getMemberType(tree->sibling->symTab->structtype, tree->sibling->value);
		    size = getMemberSize(tree->sibling->symTab->structtype, tree->sibling->value);
		    //printf("size: %d\n", size);
		    if(size>1 && strcmp(tree->sibling->name, "exp")!=0){
		          fprintf(file, "\t%s\n", "popl %eax");
		          print_char_array(file, size );
			  return;
		    }
         }		          
	 fprintf(file, "\t%s\n", "popl %ebx");
	 fprintf(file, "\t%s\n", "movl (%ebx), %eax");	 
	 switch(type){
	 case 0:
	            fprintf(file, "\t%s\n", "call cshow");          
		    break;
	 case 1:
	            fprintf(file, "\t%s\n", "call ishow");          
		    break;
	 case 2:
	            fprintf(file, "\t%s\n", "fld (%ebx)");
	            fprintf(file, "\t%s\n", "call fshow");          
		    break;
	 }
 
	 return;
      }
	if(strcmp(tree->name, "-")==0 || strcmp(tree->name, "OP")==0 || strcmp(tree->name, "cast")==0 
			|| strcmp(tree->name, "ASSIGN")==0 || 
			( strcmp(tree->name, "ID")==0 && tree->symTab->nameType==1)){
		empty();
		gen_assign(file, tree);
		int a;
		a  = pop();
		switch(a){
		case 0:
				fprintf(file, "\t%s\n", "popl %eax");
				fprintf(file, "\t%s\n", "call cshow\t\t# call cshow function"); break;
		case 1:
				fprintf(file, "\t%s\n", "popl %eax");
				fprintf(file, "\t%s\n", "call ishow\t\t# call ishow function"); break;
		case 2:
				fprintf(file, "\t%s\n", "flds (%esp)");
				fprintf(file, "\t%s\n", "call fshow");
				fprintf(file, "\t%s\n", "addl $4, %esp");   break;      
		}
		return;	
	}           
     gen_println(file, tree->next);
     
     if(strcmp(tree->name,"STRING")==0){
        fprintf(file, "\t%s\n", "movl $SYS_write, %eax\t# load the write call number");
	fprintf(file, "\t%s\n", "movl $STDOUT, %ebx\t\t# get the output channel");
	fprintf(file, "\t%s%d,%s\n", "movl $literal",tree->strIndex, "%ecx\t\t# get the literal string");
	fprintf(file, "\t%s%d,%s\n", "movl $len",tree->strIndex, "%edx\t\t# string length");
	fprintf(file, "\t%s\n", "int $0x80");
	return;
     }
     
     if(strcmp(tree->name,"INT_V")==0){
	fprintf(file, "\t%s $%s,%s\n", "movl",tree->value, "%eax\t\t# get the integer");
	fprintf(file, "\t%s\n", "call ishow\t\t# call ishow function");
	return ;
     }
     if(strcmp(tree->name,"CHAR_V")==0){
	fprintf(file, "\t%s $%s,%s\n", "movl",tree->value, "%eax\t\t# pass the char");
	fprintf(file, "\t%s\n", "call cshow\t\t# call cshow function");	

	return;        
     }
     if(strcmp(tree->name,"FLT_V")==0){
        //float f;
	//f=atof(tree->value);
	//printf("FLT: %f\n",f);
        fprintf(file, "\t%s\n", "subl $4, %esp");
	fprintf(file, "\t%s $%s, %s\n", "movl", tree->value, "(%esp)");
        fprintf(file, "\t%s\n", "flds (%esp)");
	fprintf(file, "\t%s\n", "call fshow");
	fprintf(file, "\t%s\n", "addl $4, %esp");
	return;        
     }
          
     if(strcmp(tree->name,"ID")==0){
        if(tree->symTab->nameType==0){          // if the id is a variable
		symrec *tmp = tree->symTab;
		char addr[20];
		getIDAddr(tmp,addr);
					
                if(tree->symTab->isArray==1){
		        int len;
		        len = tree->symTab->numArray;
			fprintf(file, "\t%s%s, %s\n", "leal ", addr, "%eax");
                        print_char_array(file, len);
			return;			
		}
	
		if(tree->symTab->type==0){       //if it is a char type

			fprintf(file, "\t%s %s,%s\n", "movl",addr, "%eax\t\t# pass the char");
			fprintf(file, "\t%s\n", "call cshow");		

			return;
		}
		if(tree->symTab->type==1){	
			fprintf(file, "\t%s %s,%s\n", "movl",addr, "%eax\t\t# get the integer value of the ID");
			fprintf(file, "\t%s\n", "call ishow");
			return ;
		}

		if(tree->symTab->type==2){	
			//fprintf(file, "\t%s %s,%s\n", "movl",addr, "%eax\t\t# get the float value of the ID");
			fprintf(file, "\t%s%s\n", "flds ", addr);
			fprintf(file, "\t%s\n", "call fshow");
			return ;
		}
	}
     }          
     gen_println(file, tree->sibling);
}

void print_char_array(FILE *file, int len)
{

	int i;
	//fprintf(file, "\t%s%s,%s\n", "movl ",addr, "%ecx");
	fprintf(file, "\t%s%d, %s\n", "subl $",len, "%esp");
	for(i=0;i<len;i++){
		fprintf(file, "\t%s\n", "movb (%eax), %bl");
		fprintf(file, "\t%s%d%s\n", "movb %bl, ", i,"(%esp)");
		fprintf(file, "\t%s\n", "addl $4, %eax");
	}
	fprintf(file, "\t%s\n", "movl $SYS_write, %eax\t\t# print a char array");
	fprintf(file, "\t%s\n", "movl $STDOUT, %ebx");
	fprintf(file, "\t%s\n", "movl %esp, %ecx");
	fprintf(file, "\t%s%d,%s\n", "movl $",len, "%edx");
	fprintf(file, "\t%s\n", "int $0x80");
	
	
	fprintf(file, "\t%s%d, %s\n", "addl $",len, "%esp");			
			
}

void print_nl(FILE *file)
{
	fprintf(file, "\t%s\n", "call newline");
  /*      fprintf(file, "\t%s\n", "movl $SYS_write, %eax\t\t# print a \"newline\"");
	fprintf(file, "\t%s\n", "movl $STDOUT, %ebx");
	fprintf(file, "\t%s\n", "movl $newline, %ecx");
	fprintf(file, "\t%s\n", "movl $nl_length, %edx");
	fprintf(file, "\t%s\n", "int $0x80");  
  */
}