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stage1.cpp
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// CS 4301 - Stage0 - EJ Smith, Brendan Murphey, Jacob Causer this is the current build, copy and pasted from stage0
#include <ctime>
#include <string>
#include <fstream>
#include <iostream>
#include <vector>
#include <iomanip>
#include <sstream>
#include <stack>
#include <cctype>
using namespace std;
//**********************************GLOBAL VARIABLES***********************************
const int MAX_SYMBOL_TABLE_SIZE = 256;
enum storeType {INTEGER, BOOLEAN, PROG_NAME, UNKNOWN};
enum allocation {YES, NO};
enum modes {VARIABLE, CONSTANT};
int keyCount = 12;
string keys[12] = {"program", "begin", "end", "var", "const",
"integer", "boolean", "true", "false", "not", "read", "write"};
struct entry{ // define symbol table entry format
string internalName;
string externalName;
storeType dataType;
modes mode;
string value;
allocation alloc;
int units;
};
vector<entry> symbolTable;
ifstream sourceFile;
ofstream listingFile, objectFile;
string token;
char charac;
bool errorFound = false;
int lstLineNum = 0;
char prevCharac = ' ';
int boolCount = 0;
int intCount = 0;
int overflow = 0;
bool progFound = false;
const char END_OF_FILE = '$'; // arbitrary choice
string regA = "";
int myLabelCounter = -1;
int currentTempNo = -1;
int maxTempNo = -1;
stack <string> Operator;
stack <string> Operand;
//*******************************END GLOBALS********************************************
//Stage 0
void CreateListingHeader();
void Parser();
void CreateListingTrailer();
void PrintSymbolTable();
void Prog();
void ProgStmt();
void Consts();
void Vars();
void BeginEndStmt();
void ConstStmts();
void VarStmts();
string Ids();
void Insert(string,storeType, modes, string, allocation, int);
storeType WhichType(string);
string WhichValue(string);
string NextToken();
char NextChar();
void Error(string);
string genInternalName(storeType);
bool NonKeyID();
bool isSpecial(char);
bool isLetter(char);
bool isInteger();
bool isBoolean();
//Stage 1
void EXEC_STMTS();
void EXEC_STMT();
void ASSIGN_STMT();
void READ_STMT();
void READ_LIST();
void WRITE_STMT();
void WRITE_LIST();
void EXPRESS();
void EXPRESSES();
void TERM();
void TERMS();
void FACTOR();
void FACTORS();
void PART();
bool REL_OP();
bool ADD_LEVEL_OP();
bool MULT_LEVEL_OP();
void Code(string, string operand1 = "", string operand2 = "");
bool isEXPRESS();
void EmitAdditionCode(string, string);
void EmitDivisionCode(string, string);
void EmitMultiplicationCode(string, string);
void EmitAndCode(string, string);
void EmitOrCode(string, string);
void EmitEqualsCode(string, string);
void EmitAssignCode(string, string);
void PushOperand(string);
void PushOperator(string);
string popOperand();
string popOperator();
void FreeTemp();
string GetTemp();
void EmitProgramCode();
void EmitEndCode();
void EmitReadCode(string);
void EmitWriteCode(string);
void EmitSubtractionCode(string, string);
void EmitGreaterThanCode(string, string);
void EmitGreaterThanEqualCode(string, string);
void EmitLessThanCode(string, string);
void EmitLessThanEqualCode(string, string);
void EmitEqualityCode(string, string);
void EmitNotEqualCode(string, string);
void EmitNegCode(string);
void EmitNotCode(string);
void EmitModuloCode(string, string);
//*****************************************STAGE 0 BEGIN********************************************
int main(int argc, char **argv){
sourceFile.open(argv[1]); //accepts input from argv[1]
listingFile.open(argv[2]); //generates a listing to argv[2]
objectFile.open(argv[3]); //generates an object code to argv[3]
CreateListingHeader(); //top
Parser(); //main
CreateListingTrailer(); //end
PrintSymbolTable(); //object file
return 0; //complete
}
// Creates the header forthe listing file
void CreateListingHeader(){
time_t now = time(NULL); //time (as given)
listingFile << left << "STAGE0: " << "EJ Smith, Brendan Murphey, Jacob Causer\t" << ctime(&now) << "\n"; //names
listingFile << setw(22) << "LINE NO." << "SOURCE STATEMENT\n\n"; //line numbers and source statements should be aligned under the headings
}
// Begins the program
void Parser(){
NextChar();// charac must be initialized to the first character of the source file
if(NextToken().compare("program")) //ifthe next token
Error("keyword \"program\" expected"); // process error: keyword "program" expected;
Prog();// parser implements the grammar rules, calling first rule
}
// Creates the trailer forthe listing file
void CreateListingTrailer(){
listingFile << "\nCOMPILATION TERMINATED\t" << setw(5) << ((errorFound)? '1' : '0') << " ERRORS" << " ENCOUNTERED\n";
}
// Prints the symbol table into the object file
void PrintSymbolTable(){
vector<entry>::iterator it;
time_t now = time(NULL);
objectFile << left << "STAGE1: " << "EJ Smith, Brendan Murphey, Jacob Causer\t" << ctime(&now) << "\n";
objectFile << "Symbol Table\n\n";
for(it = symbolTable.begin(); it < symbolTable.end(); ++it)
{
objectFile << left << setw(15) << it->externalName << " ";
objectFile << left << setw(4) << it->internalName << " ";
objectFile << right << setw(9) << ((it->dataType == 2)?"PROG_NAME":(it->dataType == 1)?"BOOLEAN":(it->dataType == 0)?"INTEGER":"") << " ";
objectFile << right << setw(8) << ((it->mode == 1)?"CONSTANT":(it->mode == 0)?"VARIABLE":"") << " ";
objectFile << right << setw(15) << ((it->value == "true")?"1":((it->value=="false")? "0" : it->value)) << " ";
objectFile << right << setw(3) << right << ((it->alloc)?"NO":"YES");
objectFile << setw(3) << it->units << "\n";
}
}
// Production 1
void Prog(){ //token should be "program"
if(token != "program"){
Error("keyword 'program' expected");
}
ProgStmt();
if(token == "const"){
Consts();
}
if(token == "var"){
Vars();
}
if(token != "begin"){
Error("keyword \"const\", \"var\", or \"begin\" expected"); // 11-18-15 EJ changed
}
BeginEndStmt();
if(token[0] != END_OF_FILE){
Error("no text may follow end");
}
}
// Production 2
void ProgStmt(){ //token should be "program"
string x;
if(token != "program")
Error("keyword 'program' expected");
x = NextToken();
// note: NonKeyID only checks TOKENS
if(!NonKeyID())
Error("program name expected");
if(NextToken() != ";")
Error("semicolon expected");
NextToken();
Insert(x,PROG_NAME,CONSTANT,x,NO,0);
}
// Production 3
void Consts(){ //token should be "const"
if(token != "const")
Error("keyword \"const\" expected");
NextToken();
if(!NonKeyID())
Error("non-keyword identifier must follow \"const\"");
ConstStmts();
}
// Production 4
void Vars(){ //token should be "var"
if(token != "var")
Error("keyword 'var' expected");
NextToken();
if(!NonKeyID())
Error("non-keyword identifier must follow 'var'");
VarStmts();
}
// Production 5
void BeginEndStmt(){
static int beginCounter = 0;
if (token != "begin")
Error("keyword \"begin\" expected");
else{
if (beginCounter == 0)
Code("program");
beginCounter++;
}NextToken();
if(NonKeyID() || token == "read" || token == "write" || token == ";" || token == "begin"){
EXEC_STMTS();
}if(token != "end"){
Error("keyword \"end\" expected"); // process error: keyword "end" expected
}else{
beginCounter--;
}NextToken();
if (beginCounter == 0 && token != ".")
Error("\".\" expected");
else if (beginCounter > 0 && token != ";")
Error("\";\" expected");
else if (beginCounter < 0 )
Error("need a \"begin\" before this point");
if (token == ".")
Code("end");
NextToken();
}
// Production 6
void ConstStmts(){ //token should be NON_KEY_ID
string x,y;
int spot = -1;
if(!NonKeyID())
Error("non-keyword identifier expected");
x = token;
if(NextToken() != "="){
Error("\"=\" expected");
}
y = NextToken();
if(y != "+" && y != "-" && y !="not" && !NonKeyID() && !isBoolean() && !isInteger())
Error("token to right of \"=\" illegal");
if(y == "+" || y == "-"){
NextToken();
if(!isInteger())
Error("integer expected after sign");
y = y + token;
}
if(y == "not"){
NextToken();
for(uint i = 0; i < symbolTable.size(); i++){
if(symbolTable[i].externalName == token)
spot = i;
}
if(spot != -1){
if(symbolTable[spot].dataType != BOOLEAN)
Error("boolean expected after not");
}
else if(!isBoolean())
Error("boolean expected after not");
// token was external name?
if(spot != -1){
if(symbolTable[spot].value == "true")
y = "false";
else if(symbolTable[spot].value == "false")
y = "true";
else
Error("invalid value forBOOLEAN type");
}
else if(token == "true"){
y = "false";
}else{
y = "true";
}
}
if(NextToken() != ";")
Error("\":\" expected");
Insert(x,WhichType(y),CONSTANT,WhichValue(y),YES,1);
NextToken();
if(token != "begin" && token != "var" && !NonKeyID())
Error("non-keyword identifier, \"begin\", or \"var\" expected");
if(NonKeyID())
ConstStmts();
}
// Production 7
void VarStmts(){ //token should now be NON_KEY_ID
string x, y;
if(!NonKeyID())
Error("non-keyword identifier expected");
x = Ids();
if(token != ":")
Error("\":\" expected");
NextToken();
if(token != "integer" && token != "boolean")
Error("illegal type follows \":\"");
y = token;
if(NextToken() != ";")
Error("semicolon expected");
if(y == "integer")
Insert(x, INTEGER, VARIABLE, "", YES, 1);
else if(y == "boolean")
Insert(x, BOOLEAN, VARIABLE, "", YES, 1);
else if(y == "program")
Insert(x, PROG_NAME, VARIABLE, "", NO, 0);
else
Error("not a valid storeType");
NextToken();
//ifthis doesn't work, put nexttoken before the if, and replace it with token
if(token != "begin" && !NonKeyID())
Error("non-keyword identifier or \"begin\" expected");
if(NonKeyID())
VarStmts();
}
// Production 8
string Ids(){ //token should be NON_KEY_ID
string temp,tempString;
if(!NonKeyID())
Error("non-keyword identifier expected");
tempString = token;
temp = token;
if(NextToken() == ",")
{
NextToken();
if(!NonKeyID())
Error("non-keyword identifier expected");
tempString = temp + "," + Ids();
}
return tempString;
}
// Inserts a new entry into the symbol table
void Insert(string externalName, storeType inType, modes inMode, string inValue,
allocation inAlloc, int inUnits)
{
string name;
string::iterator end = externalName.end();
for(string::iterator a = externalName.begin(); a < externalName.end(); a++){
name = ""; //initialize a new name
while((*a != ',') && (a < end) ){ //fill in name appropriately
name += *a;
a++;
}
if(!name.empty()){
if(name.length() > 15){ //ifthe name is too big (over 15), ignore characters past 15
name = name.substr(0,15);
}
for(int i = 0; i < symbolTable.size(); i++){ //ifthe name is already there, error!
if(symbolTable[i].externalName == name){
Error("multiple name definition");
}
}
if(find(keys, keys + keyCount, name) != keys + keyCount){ //see ifname matches keys
Error("illegal use of keyword"); //ifso, error
}
else{ //otherwise, set up the push_back
entry my;
if(name.length() > 15){
my.externalName = name.substr(0,15);
}else{
my.externalName = name;
}if(isupper(name[0])){
my.internalName = name;
}else{
my.internalName = genInternalName(inType);
}
if(inValue.length() > 15){
my.value = inValue.substr(0,15);
}else{
my.value = inValue;
}
my.dataType = inType;
my.mode = inMode;
my.alloc = inAlloc;
my.units = inUnits;
symbolTable.push_back(my);
}
++overflow;
if(overflow > 256)
Error("symbol table entries have exceeded the maximum allowed value");
}
}
}
// Determines which data type "name" has
storeType WhichType(string name){
string::iterator it;
vector<entry>::iterator vit;
bool isInteger = true;
if(name == "true" || name == "false")
return BOOLEAN;
if(isdigit(name[0]) || name[0] == '+' || name[0] == '-')
{
for(it = name.begin() + 1; it < name.end(); ++it)
{
if(!isdigit(*it))
isInteger = false;
}
if(isInteger)
return INTEGER;
}
for(vit = symbolTable.begin(); vit < symbolTable.end(); ++vit)
{
if(name == (*vit).externalName)
return (*vit).dataType;
}
Error("reference to undefined constant1");
}
// Determines which value "name" has
string WhichValue(string name)
{
string::iterator it;
vector<entry>::iterator vit;
bool isLiteral = true;
if(name == "true" || name == "false")
isLiteral = true;
else if(isdigit(name[0]) || name[0] == '+' || name[0] == '-')
{
for(it = name.begin() + 1; it < name.end(); ++it)
{
if(!isdigit(*it))
isLiteral = false;
}
if(isLiteral)
return name;
}
for(vit = symbolTable.begin(); vit < symbolTable.end(); ++vit)
{
if(name == (*vit).externalName)
return (*vit).value;
}
if(name == "")
Error("reference to undefined constant2");
return name;
}
// Returns the next token or end of file marker
string NextToken(){
token = "";
while (token == ""){
if(charac == '{'){ //process comment
while(true){
NextChar();
if(charac == END_OF_FILE){
break;
}else if(charac == '}'){
NextChar();
break;
}
}if(charac == END_OF_FILE){
Error("unexpected end of file");
}else if(charac == '}'){
Error("token can't start \"}\"");
}
}else if(charac == '}'){
Error("\"}\" cannot begin token");
}else if(isspace(charac)){
NextChar();
}else if(isSpecial(charac)){
token = charac;
NextChar();
}else if(charac == ':'){
token = charac;
NextChar();
if(charac == '='){
token+=charac;
NextChar();
}
}else if(charac=='<'){
token = charac;
NextChar();
if(charac=='=' || charac == '>'){
token+=charac;
NextChar();
}
}else if(charac=='>'){
token = charac;
NextChar();
if(charac=='='){
token+=charac;
NextChar();
}
}else if(charac == '_'){ //no leading _
Error("\'_\' cannot start an identifier");
}else if(isalpha(charac)){
token = charac;
charac = NextChar();
if(charac == '_'){
Error("\'_\' cannot start an identifier");
}while(isLetter(charac)){ //search lowercase, nums, and spaces. ifit's none of these, than npos is reached.
token+=charac;
NextChar();
}
}else if(isdigit(charac)){
token = charac;
while(isdigit(NextChar())){
token += charac;
}
}else if(charac == END_OF_FILE){
token = charac;
}else{
Error("illegal symbol");
}
}if(token[0] == '_'){ //no start _
Error("\"_\" cannot start an identifier");
}if(token[token.length() - 1] == '_'){ //no end _
Error("\"_\" cannot end an identifier");
}return token;
}
//special character?
bool isSpecial(char chara){
return (chara == ',' || charac == ';' || charac == '=' || charac == '+' || charac == '-' ||
charac == '.' || charac =='(' || charac ==')' || charac == '*');
}
//lowercase
bool isLetter(char chara){
return (islower(chara) || isdigit(chara) || chara == '_');
}
char NextChar(){
char myNext;
sourceFile.get(myNext);
//http://www.cplusplus.com/reference/ios/ios/good/
if(!sourceFile.good()){
charac = END_OF_FILE;
}else{
prevCharac = charac;
charac = myNext;
if(lstLineNum == 0){
lstLineNum++;
listingFile << setw(5) << right << lstLineNum << '|';
}else if(prevCharac == '\n'){
lstLineNum++;
listingFile << setw(5) << right << lstLineNum << '|';
}
listingFile << charac;
}
return charac;
}
// Displays errors to the listing file
void Error(string error){
errorFound = true;
listingFile << "\nError: Line " << lstLineNum << ": " << error << "\n";
CreateListingTrailer();
sourceFile.close();
listingFile.close();
objectFile.close();
exit(EXIT_FAILURE);
}
// Generates the internal name
string genInternalName(storeType genType){
ostringstream myOut;
if(genType == INTEGER){
myOut << "I" << intCount;
intCount++;
}else if(genType == BOOLEAN){
myOut << "B" << boolCount;
boolCount++;
}else if(genType == PROG_NAME){
if(progFound == false){
myOut << "P0";
progFound = true;
}else{
Error("only one program name allowed");
}
}
return myOut.str();
}
// Returns true if token is a NonKeyID, and false otherwise
bool NonKeyID()
{
if(token[0]=='_')
Error("cannot begin with \"_\" ");
if(isupper(token[0]))
Error("upper case characters not allowed");
if(!isalpha(token[0]))
return false;
// go through each char
for(int x = 1; x < (int)token.length(); x++)
{
if(isupper(token[x]))
Error("upper case characters not allowed");
if( !isalpha(token[x]) && !isdigit(token[x]) && token[x] != '_' )
return false;
}
return(find(keys, keys + keyCount, token) != keys + keyCount)? false : true; //token isn't key ID
}
//is it a boolean type?
bool isBoolean(){
return(token=="true" || token == "false");
}
//all chars must be a digit forit to be an integer type. is it so?
bool isInteger(){
for(int i = 0; i < (int)token.length(); i++){
if(!isdigit(token[i]))
return false;
}
return true;
}
//**********************************STAGE 1************************************************************************************************************
//STAGE 1 NEW PRODUCTIONS EJ FROM //2 TO //18
const string EXPRESSFail = "Invalid expression: \"not\", \"true\", \"false\", \"(\", \"+\", \"-\", non-key ID, or integer expected";
//2
void EXEC_STMTS(){
if(NonKeyID() || token == "read" || token == "write" || token == "begin" || token == ";"){
EXEC_STMT();
EXEC_STMTS();
}else if(token != "end")
Error("non-keyword identifier, \"read\", \"write\", or \"begin\" expected");
}
//3
void EXEC_STMT(){
if(NonKeyID()){
ASSIGN_STMT(); //ifit's not a keyID, assign it!
}else if(token == "read"){
READ_STMT();
}else if(token == "write"){
WRITE_STMT();
}else if(token == ";"){
NextToken(); //advance ;
}else if(token == "begin"){
BeginEndStmt();
}else{
Error("non-keyword id, read, or write statement expected");
}
}
//4
void ASSIGN_STMT(){
if(!NonKeyID())//check fornon key
Error("non_key_id expected");
string t = "" + token; //holds token
PushOperand(t); //push the token and move on
NextToken();
if(token != ":=")//token HAS to be := here forassignment
Error("Expected assignment operator");
else
PushOperator(":=");
NextToken();
if(isEXPRESS())
EXPRESS();
else
Error(EXPRESSFail); //need proper keywords
if(token != ";")
Error("\";\" expected "); //expected semicolon
Code(popOperator(), popOperand(), popOperand());
}
//5
void READ_STMT(){
if(token!= "read")//to read, token must be read.
Error("expected \"read\" forread statement");
NextToken(); //see what's being read
if(token != "(")//must be (forfunction
Error("\"(\" expected");
READ_LIST(); //read the list
if(NextToken()!= ";"){ //should be over
Error("Expected ;");
}
}
//6
void READ_LIST(){
if(token!= "(")//currently must be at (
Error("Expected (");
NextToken(); //ifso, proceed
string temp = Ids();
if(token!= ")"){
Error("Expected \",\" or \")\"");
}else
Code("read", temp);
}
//7
void WRITE_STMT(){
if(token != "write")
Error("Expected \"write\"");
NextToken();
if(token != "(")
Error("\"(\" expected");
WRITE_LIST();
if(NextToken()!= ";")
Error("Expected \";\"");
}
//8
void WRITE_LIST(){
if(token != "(")
Error("Expected \"(\"");
NextToken();
string temp = Ids();
if(token != ")"){ //is "," needed to be tested here?
Error("Expected \",\" or \")\"");
}else
Code("write", temp);
}
//9
void EXPRESS(){
if(!isEXPRESS())
Error(EXPRESSFail);
TERM();
//is NextToken()needed here?
if(REL_OP()){
EXPRESSES();
}else if(token != ")" && token != ";"){
Error("Invalid expression");
}
}
//10
void EXPRESSES(){
if(!REL_OP())
Error("\"<>\", \"=\", \"<=\", \">=\", \"<\", or \">\" expected");
PushOperator(token);
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
else
TERM();
Code(popOperator(), popOperand(), popOperand());
//is NextToken()needed here?
if(REL_OP()){
EXPRESSES();
}else if(token != ")" && token != ";" && token != ",")
Error("Invalid expression");
}
//11
void TERM(){
if(!isEXPRESS())
Error(EXPRESSFail);
FACTOR();
if(ADD_LEVEL_OP()){
TERMS();
}else if(!REL_OP() && token != ")" && token != ";"){
Error("Invalid expression");
}
}
//12
void TERMS(){
if(!ADD_LEVEL_OP())
Error("\"-\", \"+\", or \"or\" expected");
PushOperator(token);
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
else
FACTOR();
Code(popOperator(), popOperand(), popOperand());
if(ADD_LEVEL_OP()){
TERMS();
}else if(!REL_OP() && token != ")" && token != ";"){
Error("Invalid expression");
}
}
//13
void FACTOR(){
if(!isEXPRESS())
Error(EXPRESSFail);
PART();
if(MULT_LEVEL_OP()){
FACTORS();
}else if(!REL_OP() && !(token == ")" || token == ";") && !ADD_LEVEL_OP()){
Error("Invalid expression");
}
}
//14
void FACTORS(){
if(!MULT_LEVEL_OP())
Error("invalid FACTORS: \"*\",\" div\", \"mod\", or \"and\" expected");
PushOperator(token);
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
else
PART();
Code(popOperator(), popOperand(), popOperand());
if(MULT_LEVEL_OP()){
FACTORS();
}else if(!REL_OP() && !(token == ")" || token == ";") && !ADD_LEVEL_OP()){
Error("Multiplicative level operator expected");
}
}
//15
void PART(){
if(token == "not"){
NextToken();
if(token == "("){
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
EXPRESS();
if(token !=")")
Error("\")\" expected");
NextToken();
Code("not", popOperand());
}else if(isBoolean()){
if(token == "true"){
PushOperand("false");
NextToken();
}else{
PushOperand("true");
NextToken();
}
}else if(NonKeyID()){
Code("not", token);
NextToken();
}
}else if(token == "+"){
NextToken();
if(token == "("){
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
EXPRESS();
if(token != ")"){
Error("\")\" expected");
}
NextToken();
}else if(isInteger()|| NonKeyID()){
PushOperand(token);
NextToken();
}else{
Error("\"(\", integer, or non-keyword id expected");
}
}else if(token == "-"){
NextToken();
if(token == "("){
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
EXPRESS();
if(token != ")")
Error("\")\" expected");
NextToken();
Code("neg", popOperand());
}else if(isInteger()){
PushOperand("-" + token);
NextToken();
}else if(NonKeyID()){
Code("neg", token);
NextToken();
}
}else if(isInteger()|| isBoolean()|| NonKeyID()){
PushOperand(token);
NextToken();
}else if(token == "("){
NextToken();
if(!isEXPRESS())
Error(EXPRESSFail);
EXPRESS();
if(token !=")"){
Error("\")\" expected");
}else
NextToken();
}else{
Error("Illegal keyword");
}
}
//16
bool REL_OP(){
return (token == "<>" || token == "=" || token == "<=" || token == ">=" || token == "<" || token == ">");
}
//17
bool ADD_LEVEL_OP(){
return (token == "-" || token == "+" || token == "or");
}
//18
bool MULT_LEVEL_OP(){
return (token == "*" || token == "div" || token == "mod" || token == "and");
}
//code
void Code(string myOperator, string operand1, string operand2){
if(myOperator == "program"){
EmitProgramCode();
}else if(myOperator == "end"){