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

     if(strcmp(tree->value, "+O")==0){    // if it's ++id
        if(a!=2.0){     
		fprintf(file, "\t%s\n","incl (%eax)"); 
		fprintf(file, "\t%s\n","push (%eax)");
	}else{
		fprintf(file, "\t%s\n", "fld1");
		fprintf(file, "\t%s\n", "flds (%eax)");
		fprintf(file, "\t%s\n", "faddp %st, %st(1)");
		fprintf(file, "\t%s\n", "fstps (%eax)");
		fprintf(file, "\t%s\n", "push (%eax)");
	}		  
     }
     if(strcmp(tree->value, "-O")==0){    // if it's --id
        if(a!=2.0){      
		fprintf(file, "\t%s\n","decl (%eax)");
		fprintf(file, "\t%s\n","push (%eax)"); 
	}else{
		fprintf(file, "\t%s\n", "fld1");
	  	fprintf(file, "\t%s\n", "flds (%eax)");
		fprintf(file, "\t%s\n", "fsubp %st, %st(1)");
		fprintf(file, "\t%s\n", "fstps (%eax)");      
          	fprintf(file, "\t%s\n", "push (%eax)");
	} 
     }
     push(a);              
}

void gen_assign(FILE *file, symnode *tree)
{
   if(tree==NULL) return;

   if(strcmp(tree->name, "ASSIGN")==0){      // LHS should be the address, RHS is the value
	gen_assign_op(file,tree);  //already push ecx onto the stack
	//fprintf(file, "\t%s\n", "pushl %eax");	
	return ;
   }   

   if(strcmp(tree->name, "offset")==0){
         gen_OffsetIDAddress( file, tree);
	 fprintf(file, "\t%s\n", "popl %eax");
	 fprintf(file, "\t%s\n", "pushl (%eax)");
	 int a;
	 a=pop();
	 //printf("offset : %d\n",a);
	 push(a);
	 return;
   }
   if(strcmp(tree->name, "unaryOp")==0){
         gen_unary_op(file, tree);
	 return;
   } 
    
   gen_assign(file, tree->next);
   gen_assign(file, tree->sibling);

  
   if(strcmp(tree->name,"INT_V")==0){
	fprintf(file, "\t%s%s\n", "pushl $",tree->value);
	push(1.0);
	return;
   }
   
   if(strcmp(tree->name,"FLT_V")==0){
	fprintf(file, "\t%s%s\n", "pushl $",tree->value);
	push(2.0);
	return;
   }
      
   if(strcmp(tree->name,"CHAR_V")==0){
	fprintf(file, "\t%s%s\n", "pushl $",tree->value);
	push(0.0);
	return;
   }
   
   if(strcmp(tree->name,"-")==0){
        float a;
	a=pop();
	if(a==2.0){
		fprintf(file, "\t%s\n", "xorl $-2147483648, (%esp)");
		push(2.0);
	}else{         
		fprintf(file, "\t%s\n", "negl  (%esp)");
		push(1.0);
	}
	return;	 
   }
   if(strcmp(tree->name,"!")==0){
   	float a;
	a=pop();
	if(a==2){
		printf("--compiling messege (line %d): \"!\" operation not support float at the moment\n", tree->line);
		exit(0);
	}
	fprintf(file,"\t%s\n","cmpl $0, (%esp)");
	fprintf(file,"\t%s\n","sete %al");
	fprintf(file,"\t%s\n","movzbl %al, %eax");
	fprintf(file,"\t%s\n","movl %eax, (%esp)");
	push(1);
	return;
	
   }
   if(strcmp(tree->name,"cast")==0){
              float a;
	      a = pop();
	      
              if(strcmp(tree->value,"char")==0){
	          if(a==2.0){
		       printf("--compiling messege (line %d): Cannot cast from float to char\n", tree->line);
		       exit(0);
		  }
		  
		  push(0.0);
	      }
              if(strcmp(tree->value,"int")==0){
	          if(a==2.0){
		 	fprintf(file, "\t%s\n", "flds (%esp)");
		        fprintf(file, "\t%s\n", "subl $4, %esp");
			fprintf(file, "\t%s\n", "fnstcw (%esp)\t\t# save the cast flag");
			fprintf(file, "\t%s\n", "movw (%esp), %cx");
			fprintf(file, "\t%s\n", "movb $12, %ch");
			fprintf(file, "\t%s\n", "movw %cx,  2(%esp)");
			fprintf(file, "\t%s\n", "fldcw 2(%esp)\t\t# set the new cast flag");
			
			fprintf(file, "\t%s\n", "fistpl 4(%esp)");
			fprintf(file, "\t%s\n", "fldcw (%esp)\t\t# restore the cast flag as before");
			fprintf(file, "\t%s\n", "addl $4, %esp");
			//fprintf(file, "\t%s\n",  "fistpl (%esp)");
		  }
		  push(1.0); 
	      }
              if(strcmp(tree->value,"float")==0){
	               if(a==2.0){
		                 printf("--compiling messege (line %d): Cannot cast from float to char\n", tree->line);
		                 exit(0);
		       }	      
	                if(a==1.0 ){
		        	fprintf(file, "\t%s\n", "fildl (%esp)");
				fprintf(file, "\t%s\n", "fstps (%esp)");
		       }
		       push(2.0);
	      }
              if(strcmp(tree->value,"double")==0){
	      }
              if(strcmp(tree->value,"struct")==0){
	      }
	      return;
   }   
   
      
   if(strcmp(tree->name,"ID")==0){
      if(tree->symTab->nameType ==0){                   //if is a variable
         char addr[20];
	 getIDAddr(tree->symTab, addr);
	 if((tree->symTab->type==5) || (tree->symTab->isArray==1)){
	    fprintf(file, "\t%s %s, %s\n", "leal",  addr, "%eax\t\t# operand is array or structure");
	    //if(tree->symTab->type=5)
	    	push(1.0);            //  save the type in stack
	    //else
	    	//push(tree->symTab->type);
	 }else{
	    float type;
            fprintf(file,"\t%s%s\n","pushl ",addr);
	    type=(float)(tree->symTab->type);        // save the type in stack
	    //if(type == 0.0) type = 1.0;
	    push(type);
	    return;
	    }
      }
      else{
 	fprintf(file, "\t%s %s\t\t# call function to get result to return\n", "call", tree->symTab->name);
	int i;
	for(i=0;i<tree->symTab->numArgs;i++){
	    fprintf(file, "\t%s\n", "pop %edx\t\t# release pushed arguments memory after call");
	    pop();    // pop the saved types
	}
	push((float)(tree->symTab->type));    // save the returned  value type
      }
      fprintf(file, "\t%s\n", "pushl %eax");
      return;
   }
   
   if(strcmp(tree->name, "CMP")==0){
        gen_relation_code(file, tree);
	fprintf(file, "\t%s\n", "pushl %eax");
	push(1.0);
	return;  
   }

   if(strcmp(tree->name, "&&")==0){
        gen_logic_and(file); 
	fprintf(file, "\t%s\n", "pushl %eax");
	return;  
   }      

   if(strcmp(tree->name, "||")==0){
        gen_logic_or(file);
	fprintf(file, "\t%s\n", "pushl %eax");
	return;  
   }   
          
   if(strcmp(tree->name,"OP")==0){
        fprintf(file, "\t%s\n", "\t\t\t# arithmetic calculate");
        gen_operation(file, tree);     
        return;
   }
}

void getOperator(const char* opType, char * operator)
{
    //if(opType==NULL) return ;
    if(strcmp(opType,"+")==0)  strcpy(operator, "addl");
    if(strcmp(opType,"-")==0)  strcpy(operator, "subl");
    if(strcmp(opType,"*")==0)  strcpy(operator, "imull");
    //if(strcmp(opType,"/")==0)  strcpy(operator, "idivl");     
    //if(strcmp(opType,"<<")==0)  strcpy(operator, "sall");            
    //if(strcmp(opType,"<<")==0)  strcpy(operator, "sarl");
    if(strcmp(opType,"&")==0)  strcpy(operator, "andl");
    if(strcmp(opType,"|")==0)  strcpy(operator, "orl");
    if(strcmp(opType,"^")==0)  strcpy(operator, "xorl");
}

void gen_operation(FILE *file, symnode *tree)
{
       char operator[20];
       float a, b; 

	b=pop();
	a=pop();       
        if(strcmp(tree->value, "/")==0){    // divide always uses FPU to calculate
		if((b==1.0 || b==0.0)  && (a==0.0 || a==1.0)){
			fprintf(file, "\t%s\n", "popl %ebx");
			fprintf(file, "\t%s\n", "popl %eax");  
			fprintf(file, "\tcltd\n");
			fprintf(file, "\t%s\n","idivl %ebx");
			fprintf(file, "\t%s\n", "pushl %eax");
			push(1.0);
		}else{
			if(b==2.0)
				fprintf(file, "\t%s\n", "fld (%esp)");
			else
				fprintf(file, "\t%s\n", "fildl (%esp)");
			if(a==2.0)
				fprintf(file, "\t%s\n", "fld 4(%esp)");
			else
				fprintf(file, "\t%s\n", "fildl 4(%esp)");			
			fprintf(file, "\t%s\n", "fdivp %st, %st(1)");
			fprintf(file, "\t%s\n", "fstps 4(%esp)");
			fprintf(file, "\t%s\n", "addl $4, %esp");
			
			push(2.0);
		}        
                return;	    
        }
       
	if(strcmp(tree->value, "%")==0){
        	if((b==1.0 || b==0.0)  && (a==0.0 || a==1.0)){	
			fprintf(file, "\t%s\n", "popl %ebx");
			fprintf(file, "\t%s\n", "popl %eax");  	
			fprintf(file, "\tcltd\n");
			fprintf(file, "\t%s\n","idivl %ebx");
			fprintf(file, "\t%s\n","movl %edx, %eax");
			fprintf(file, "\t%s\n", "pushl %eax");
			push(1.0);
			return;
		}
	}
	
	if(strcmp(tree->value, "<<")==0){
        	if(b==1.0 && a==1.0){	
			fprintf(file, "\t%s\n", "popl %ecx");
			fprintf(file, "\t%s\n", "popl %eax");  	
			
			fprintf(file, "\t%s\n","sall %cl, %eax");
			fprintf(file, "\t%s\n", "pushl %eax");
			push(1.0);
			return;
		}
	}

	if(strcmp(tree->value, ">>")==0){
		if(b==1.0 && a==1.0){
			fprintf(file, "\t%s\n", "popl %ecx");
			fprintf(file, "\t%s\n", "popl %eax");  	
			
			fprintf(file, "\t%s\n","sarl %cl, %eax");
			fprintf(file, "\t%s\n", "pushl %eax");
			push(1.0);
			return;
		}
	}
        if((b==1.0 || b==0.0)  && (a==0.0 || a==1.0)){		
		fprintf(file, "\t%s\n", "popl %ebx");
		  		
		getOperator(tree->value, operator);
		if(strcmp(tree->value,"+")==0 || strcmp(tree->value,"-")==0){
			fprintf(file, "\t%s %s, %s\n",operator, "%ebx", "(%esp)");
		}else{
			fprintf(file, "\t%s\n", "popl %eax");
			fprintf(file, "\t%s %s, %s\n",operator, "%ebx", "%eax");
			fprintf(file, "\t%s\n", "pushl %eax");
		}
		push(1.0);
		return;
	}else{
		if(b==2.0)
			fprintf(file, "\t%s\n", "flds (%esp)");
		else
			fprintf(file, "\t%s\n", "fildl (%esp)");
		if(a==2.0)
			fprintf(file, "\t%s\n", "flds 4(%esp)");
		else
			fprintf(file, "\t%s\n", "fildl 4(%esp)");
			
		if(strcmp(tree->value, "+")==0){
		        fprintf(file, "\t%s\n", "faddp %st, %st(1)");
		}
		if(strcmp(tree->value, "-")==0){
		        fprintf(file, "\t%s\n", "fsubp %st, %st(1)");
		}
		if(strcmp(tree->value, "*")==0){
		        fprintf(file, "\t%s\n", "fmulp %st, %st(1)");
		}
		fprintf(file, "\t%s\n", "fstps 4(%esp)");
		fprintf(file, "\t%s\n", "addl $4, %esp");
		
		push(2.0);		
	}	
}

void gen_assign_op(FILE *file, symnode *tree)
{
        if(tree==NULL) return;
	//printf("node:%s  value:%s  n-name:%s s-name:%s\n", tree->name,tree->value,tree->next->name,tree->sibling->name);
	if(strcmp(tree->next->name, "ID")==0 && strcmp(tree->value, "=")==0 && 
		(strcmp(tree->sibling->name, "CHAR_V")==0|| strcmp(tree->sibling->name, "INT_V")==0 ||
			 strcmp(tree->sibling->name, "FLT_V")==0 )){
		//printf("hehehehe\n");
		char addr[40];
		pop();
		pop();
		getIDAddr(tree->next->symTab, addr);
		if( (tree->next->symTab->type==0 && strcmp(tree->sibling->name, "FLT_V")!=0) ||
		    (tree->next->symTab->type==1 && strcmp(tree->sibling->name, "FLT_V")!=0) ||
		    (tree->next->symTab->type==2 && strcmp(tree->sibling->name, "FLT_V")==0)  ){
			
			fprintf(file, "\t%s%s, %s\n", "movl $", tree->sibling->value, addr);
			
			fprintf(file, "\t%s\n", "pushl %eax");
			push(1.0);	     
			return;
		}
	}	
	
	
	float a,b;
	gen_OffsetIDAddress(file, tree->next);
	a=pop(); 
	gen_assign(file, tree->sibling);
	b=pop();
	
	//printf("ass: a:%f, b:%f\n",a,b);
	if(strcmp(tree->value,"=")==0){
	         if( ((a==0.0 || a==1.0) && (b==0.0 || b==1.0)) || (a==2.0 && b==2.0)){
			fprintf(file, "\t%s\n","popl %ebx"); 
			fprintf(file, "\t%s\n","popl %eax"); 	
			fprintf(file, "\t%s\n", "movl %ebx, (%eax)");   
			fprintf(file, "\t%s\n", "pushl (%eax)");
			if(a==1.0) push(1.0);
			if(a==2.0) push(2.0);
		 }
		 if((a==0.0 || a==1.0) && b==2.0){

		 	fprintf(file, "\t%s\n", "flds (%esp)");
			fprintf(file, "\t%s\n", "popl %ebx");
			fprintf(file, "\t%s\n", "popl %eax");			
		        fprintf(file, "\t%s\n", "subl $4, %esp");
			fprintf(file, "\t%s\n", "fnstcw (%esp)\t\t# save the cast flag");
			fprintf(file, "\t%s\n", "movw (%esp), %cx");
			fprintf(file, "\t%s\n", "movb $12, %ch");
			fprintf(file, "\t%s\n", "movw %cx,  2(%esp)");
			fprintf(file, "\t%s\n", "fldcw 2(%esp)\t\t# set the new cast flag");
			
			fprintf(file, "\t%s\n", "fistpl (%eax)");
			fprintf(file, "\t%s\n", "fldcw (%esp)\t\t# restore the cast flag as before");
			fprintf(file, "\t%s\n", "addl $4, %esp");
			fprintf(file, "\t%s\n", "push (%eax)");
			push(1.0);
		 }
		 if(a==2.0 && (b==0.0 || b==1.0)){
		 	fprintf(file, "\t%s\n", "fildl (%esp)");
			fprintf(file, "\t%s\n", "movl 4(%esp), %eax");
			fprintf(file, "\t%s\n", "fstps (%eax)");
			fprintf(file, "\t%s\n", "popl %ebx");
			fprintf(file, "\t%s\n", "popl %ebx");
			fprintf(file, "\t%s\n", "push (%eax)");
			push(2.0);
		 }		 
		 return;
	}
	if(strcmp(tree->value,"+=")==0){
        	if((b==1.0 || b==0.0)  && (a==0.0 || a==1.0)){		
			fprintf(file, "\t%s\n","popl %ebx"); 
			fprintf(file, "\t%s\n","popl %eax"); 	
			fprintf(file, "\t%s\n", "addl %ebx, (%eax)");
			fprintf(file, "\t%s\n", "pushl (%eax)");
			push(1.0);
			return;
		}
		
		if(b==2.0)
			fprintf(file, "\t%s\n", "flds (%esp)");
		else
			fprintf(file, "\t%s\n", "fildl (%esp)");
			
		fprintf(file, "\t%s\n", "popl %ebx");
		fprintf(file, "\t%s\n", "popl %eax");
				
		if(a==2.0)
			fprintf(file, "\t%s\n", "flds (%eax)");
		else
			fprintf(file, "\t%s\n", "fildl (%eax)");
		
		fprintf(file, "\t%s\n", "faddp %st, %st(1)");
		 if( a==2.0){	
			fprintf(file, "\t%s\n", "fstps (%eax)");