pass1.c

51模拟器 51模拟器 51模拟器

				
				for(m=0;m<info->nobytes;m++)
				{
					fprintf(fpdest,"%.4X %.2X\n",LocCounter,info->hex_array[m]);  //writing into temp hexfile...
					LocCounter++;
				}		
			
			
				//fprintf(fpdest,"%.4X %.2X\n",LocCounter,info->hex_array[0]);  //writing into temp hexfile...
				//LocCounter += info->nobytes ;			// incrementing the LC by sizeof present instruction...
				
				
				//printf("%s\n",AssemblyInstruction);
			}
		//sscanf(buff,"%s:%s",Label,Mnemonic);
		
		//printf("%s %s\n",Label,Mnemonic);   */
		



//	}
	
	
		else   // code to handle gas51 special escape sequence...
		{
			if(pat_index(buff,":start"))
				{
					strcpy(temp_info->file,gas51_file_being_assembled);
					temp_info->file_line_no = gas51_line_no ;
					
					push(temp_info);     // pushing the current file info into stack...
					//push(gas51_line_no);
					sscanf(buff,"%c%s%s",&ch,gas51_file_being_assembled,str); //reinit'ing file and line no...	
					gas51_line_no = 0 ;
				}
			else
				if(pat_index(buff,":end"))
					{
						temp_info=pop();
					        strcpy(gas51_file_being_assembled,temp_info->file);
						gas51_line_no = temp_info->file_line_no;	
						gas51_line_no--; // to compensate for the '++' op at start...				
						//current_line_no=pop();
					
					}
					
			
		}
	
	
	
	
	
    }  


	
	
	
	
for(i=0;i<=20;i++)
	
	if(strlen(gas51_symbol_table[i].Symbol)!=0)	
		printf("%s  ->   %X\n",gas51_symbol_table[i].Symbol,gas51_symbol_table[i].Address );
dump_file(fpdest);


return fpdest;


}




struct instruct_info  *assemble(char *Instruction)

//int *assemble(char *Instruction)
{
	
	//static int hex_array[3] ;
	unsigned int i;
	static char tokens[5][10],newtokens[5][10],ins[20];  //a 2D  array of chars to hold instruction tokens...
	char found_flag=0;  //flag to denote match status -> 0 means match not found while 1 means match found...
	int num,m,l ;	
/*	tokens[0]=malloc(10*sizeof(char));
	tokens[1]=malloc(10*sizeof(char));
	tokens[2]=malloc(10*sizeof(char));
	tokens[3]=malloc(10*sizeof(char));
	tokens[4]=malloc(10*sizeof(char));   */
	
	

	//hex_array[0]=-1;  
	//hex_array[1]=-1;     //initialising the array properly before continuing...
	//hex_array[2]=-1;
	
	for (i=0;i<=0xFF;i++)
	{
		if(!strcasecmp(instructions[i].mnemonic,Instruction ))
		{
			found_flag = 1;			// this is the code to test for 1 byte  ins...
			break ;
		}
		
	
	}
	
	
	if(found_flag==1)  //means instruction matched with opcode...
	{
		info->hex_array[0] = instructions[i].hex_code;
		info->nobytes = 1;
		//info = &instructions[i] ;
		return info ;
		//return hex_array;
	
	}
	
	
	else
	{
		//do some stuff here to match a 2 byte or 3 byte instruction...
		// and break the loop immediately if a match occurs..
	
		 num = get_tokens(tokens,Instruction);  //all tokens copied into token array...returns total number of tokens...
		 
		if ((strcasecmp(tokens[0],"cjne")==0) && (num > 4)  )  // when a cjne ins contains more than 4 tokens...
       			{
				gas51_errno = 5 ;
				gas51_perror() ;

			}			

		else if ( (strcasecmp(tokens[0],"cjne")==0) && (num < 4)  )  // when a cjne ins contains less  than 4 tokens...
		{
			gas51_errno = 6 ;
			gas51_perror();
							

		}			
	
		else if( ((strcasecmp(tokens[0],"ljmp")==0) ||  (strcasecmp(tokens[0],"lcall")==0)  ) &&  (num>2)  )
		{
				gas51_errno = 5 ;
				gas51_perror() ;

		}
		
		else if( ((strcasecmp(tokens[0],"ljmp")==0) ||  (strcasecmp(tokens[0],"lcall")==0)  ) &&  (num<2)  )
		{
				gas51_errno = 6 ;
				gas51_perror() ;

		}    
		
					// the basic strategy in this if-else ladder is that execution proceeds only when the number of
					// tokens are *EXACTLY* the same as required by the instruction being assembled or the program 
					//is exited and an error is given, stating either extra or less tokens than expected...   ;) 

		
		
//	else if(     (strcasecmp(tokens[0],"inc")==0)  ||  (strcasecmp(tokens[0],"dec")==0)  ||  (strcasecmp(tokens[0],"ajmp")==0) ||  (strcasecmp(tokens[0],"acall")==0)||  (strcasecmp(tokens[0],"jz")==0)   ||  (strcasecmp(tokens[0],"jnz")==0)  || (strcasecmp(tokens[0],"sjmp")==0) ||  (strcasecmp(tokens[0],"cpl")==0)  || (strcasecmp(tokens[0],"push")==0) ||  (strcasecmp(tokens[0],"clr")==0)  || (strcasecmp(tokens[0],"pop")==0)  ||  (strcasecmp(tokens[0],"setb")==0) ||  && (num>2)  )  



		else if( ((strcasecmp(tokens[0],"inc")==0)   ||  (strcasecmp(tokens[0],"dec")==0)   || \
			  (strcasecmp(tokens[0],"ajmp")==0)  ||  (strcasecmp(tokens[0],"acall")==0) || \
			  (strcasecmp(tokens[0],"jz")==0) ||	(strcasecmp(tokens[0],"jnz")==0)    || \
			  (strcasecmp(tokens[0],"sjmp")==0) ||  (strcasecmp(tokens[0],"cpl")==0)    || \
       			  (strcasecmp(tokens[0],"push")==0) ||  (strcasecmp(tokens[0],"clr")==0)    || \
       			  (strcasecmp(tokens[0],"pop")==0) ||  (strcasecmp(tokens[0],"setb")==0) )  && \
			       								      (num>2)  )
			
		{
				gas51_errno = 5 ;
				gas51_perror() ;

		}  


//		else if( ((strcasecmp(tokens[0],"inc")==0) ||  (strcasecmp(tokens[0],"dec")==0) || (strcasecmp(tokens[0],"ajmp")==0)   ) &&  (num<2)  )

		else if(((strcasecmp(tokens[0],"inc")==0)  ||  (strcasecmp(tokens[0],"dec")==0)  || \
			 (strcasecmp(tokens[0],"ajmp")==0) ||  (strcasecmp(tokens[0],"acall")==0)|| \
			 (strcasecmp(tokens[0],"jz")==0)   ||  (strcasecmp(tokens[0],"jnz")==0)  || \
		         (strcasecmp(tokens[0],"sjmp")==0) ||  (strcasecmp(tokens[0],"cpl")==0)  || \
			 (strcasecmp(tokens[0],"push")==0) ||  (strcasecmp(tokens[0],"clr")==0)  || \
			 (strcasecmp(tokens[0],"pop")==0)  ||  (strcasecmp(tokens[0],"setb")==0)  ) && (num<2)  )
		{
				gas51_errno = 6 ;
				gas51_perror() ;

		}   


		
		else if((strcasecmp(tokens[0],"cjne"))  &&  (strcasecmp(tokens[0],"ljmp" ))  && \
			(strcasecmp(tokens[0],"lcall")) &&  (strcasecmp(tokens[0],"inc" ))   && \
			(strcasecmp(tokens[0],"dec" ))  &&  (strcasecmp(tokens[0],"ajmp" ))  && \
	  		(strcasecmp(tokens[0],"acall")) &&  (strcasecmp(tokens[0],"jz" ))    && \
			(strcasecmp(tokens[0],"jnz" ))  &&  (strcasecmp(tokens[0],"sjmp" ))  && \
			(strcasecmp(tokens[0],"cpl" ))  &&  (strcasecmp(tokens[0],"push" ))  && \
			(strcasecmp(tokens[0],"clr" ))  &&  (strcasecmp(tokens[0],"pop" ))   && \
			(strcasecmp(tokens[0],"setb" )) &&  (num > 3 ) )					


									// region of code where number of tokens present	
		{							// are checked for correctness
			gas51_errno = 5 ;				//this step need not be repeated later on
			gas51_perror();					//during matching 3 byte instructions...
			


		}   
		
	
//	        else if( strcasecmp(tokens[0],"cjne")  && (strcasecmp(tokens[0],"ljmp" ))  &&  (strcasecmp(tokens[0],"lcall" )) && (strcasecmp(tokens[0],"inc" )) &&  (strcasecmp(tokens[0],"dec" )) && (num < 3 ) )	
		else if( (strcasecmp(tokens[0],"cjne"))  && (strcasecmp(tokens[0],"ljmp" ))  && \
				(strcasecmp(tokens[0],"lcall" )) && (strcasecmp(tokens[0],"inc" )) &&  \
				(strcasecmp(tokens[0],"dec" )) &&    (strcasecmp(tokens[0],"ajmp" )) && \
				(strcasecmp(tokens[0],"acall" )) &&  (strcasecmp(tokens[0],"jz" )) && \
				(strcasecmp(tokens[0],"jnz" )) &&  (strcasecmp(tokens[0],"sjmp" )) && \
				(strcasecmp(tokens[0],"cpl" )) &&  (strcasecmp(tokens[0],"push" )) && \
				(strcasecmp(tokens[0],"clr" )) &&  (strcasecmp(tokens[0],"pop" )) && \
				(strcasecmp(tokens[0],"setb" )) && (num < 3 ) )				
		{

			gas51_errno = 6 ;
			gas51_perror();

		}   

		else 
		{	//everything ok...number of tokens are correct...proceeding with matching process...
			
			
                  
			for(i=0;i<num;i++)
			{
			/*	if(!strcasecmp(tokens[i],"A"))
				{
					
					strcpy(tokens[i],"0E0");
					//continue ;
				}  */
						
				if(!strcasecmp(tokens[i],"B"))
				{
					strcpy(tokens[i],"0F0");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0xF0);
					//continue ;
				}

				else
				if(!strcasecmp(tokens[i],"PSW"))
				{
					strcpy(tokens[i],"0D0");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0xD0);
					//continue ;
				}
				
				else
				if(!strcasecmp(tokens[i],"DPH"))
				{
					strcpy(tokens[i],"83");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x83);
					//continue ;
				}
				
				else
				if(!strcasecmp(tokens[i],"DPL"))
				{
					strcpy(tokens[i],"82");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x82);
					//continue ;
				}
				
				
				else
				if(!strcasecmp(tokens[i],"P0"))
				{
					strcpy(tokens[i],"80");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x80);
					//continue ;
				}
				
				
				else
				if(!strcasecmp(tokens[i],"P1"))
				{
					strcpy(tokens[i],"90");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x90);
					//continue ;
				}
				
				
				else
				if(!strcasecmp(tokens[i],"P2"))
				{
					strcpy(tokens[i],"0A0");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0xA0);
					//continue ;
				}
				
				else
				if(!strcasecmp(tokens[i],"P3"))
				{
					strcpy(tokens[i],"0B0");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0xB0);
					//continue ;
				}
			 
   				else
				if(!strcasecmp(tokens[i],"IP"))
				{
					strcpy(tokens[i],"0B8");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0xb8);
					//continue ;
				}


				else
				if(!strcasecmp(tokens[i],"SP"))
				{
					strcpy(tokens[i],"81");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x81);
					//continue ;
				}
						
				else
				 if(!strcasecmp(tokens[i],"IE"))
				{
					strcpy(tokens[i],"0A8");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0xA8);
					//continue ;
				}


				else
				if(!strcasecmp(tokens[i],"TMOD"))
				{
					strcpy(tokens[i],"89");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x89);
					//continue ;
				}



				else
				if(!strcasecmp(tokens[i],"TCON"))
				{
					strcpy(tokens[i],"88");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x88);
					//continue ;
				}




				else
				if(!strcasecmp(tokens[i],"TH0"))
				{
					strcpy(tokens[i],"8C");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x8C);
					//continue ;
				}


				else
				if(!strcasecmp(tokens[i],"TL0"))
				{
					strcpy(tokens[i],"8A");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x8A);
					//continue ;
				}

				else
				if(!strcasecmp(tokens[i],"TH1"))
				{
					strcpy(tokens[i],"8D");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x8D);
					//continue ;
				}


	
				else
				if(!strcasecmp(tokens[i],"TL1"))
				{
					strcpy(tokens[i],"8B");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x8B);
					//continue ;
				}

				else
				if(!strcasecmp(tokens[i],"SCON"))
				{
					strcpy(tokens[i],"98");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x98);
					//continue ;
				}

				else
				if(!strcasecmp(tokens[i],"SBUF"))
				{
					strcpy(tokens[i],"99");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x99);
					//continue ;
				}

				else
				if(!strcasecmp(tokens[i],"PCON"))
				{
					strcpy(tokens[i],"87");
					//fprintf(fpprehex,"%.4X %.2X\n",addr,0x87);
					//continue ;
				}





			}
			
			
			
			
			
			
			for(i=0,m=1,l=0;i<num;i++)
		     {
			
			
			if (!isstandard(tokens[i]) )   //isstandard() returns 1 if standard , 0 if non-standard token...
			{
				
				
				
				if(islabel(tokens[i])) //islabel() returns number of tokens which are labels , 0 if none...
				{
									//this code handles the token if it is a label...
					info->label_flag++ ;
					strcpy(info->labels[l],tokens[i]);
					strcpy(newtokens[i],"ADDR");   //ADDR placeholder copied into newly created tokens...
					l++;
				}

		   else
				
/*brace marker**/    {
				
				
				
				info->label_flag=0;
				
				if(pat_index(tokens[i],"#"))
					strcpy(newtokens[i],"#DATA");
				
				else 
					strcpy(newtokens[i],"ADDR");
			
				if(tokens[i][0]!='#')
				{
					sscanf(tokens[i],"%X",&info->hex_array[m]);  // writing the operand in hex...
					m++;
				}
				
				else if(tokens[i][0]=='#')
				{
					sscanf(substr(tokens[i],2,strlen(tokens[i])-1) , "%X" ,&info->hex_array[m] );           
					m++;
				}
										
/** brace marker**/    }
			
			
		   }
			   else
				strcpy(newtokens[i],tokens[i]);   //standard tokens are being copied into newtokens array as-it-is...
		  //      	
 			
                    }