# h1
```c=
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
// for lex
#define MAXLEN 256
// Token types
typedef enum {
UNKNOWN, END, ENDFILE,
INT, ID,
ADDSUB, MULDIV,
ASSIGN,
LPAREN, RPAREN,
INCDEC,
OR,AND,XOR,
} TokenSet;
TokenSet getToken(void);
TokenSet curToken = UNKNOWN;
char lexeme[MAXLEN];
// Test if a token matches the current token
int match(TokenSet token);
// Get the next token
void advance(void);
// Get the lexeme of the current token
char *getLexeme(void);
// for parser
#define TBLSIZE 64
// Set PRINTERR to 1 to print error message while calling error()
// Make sure you set PRINTERR to 0 before you submit your code
#define PRINTERR 1
// Call this macro to print error message and exit the program
// This will also print where you called it in your program
// Error types
// Structure of the symbol table
typedef struct {
int val;
char name[MAXLEN];
} Symbol;
// Structure of a tree node
typedef struct _Node {
TokenSet data;
int val,ever;
char lexeme[MAXLEN];
struct _Node *left;
struct _Node *right;
} BTNode;
int sbcount = 0;
Symbol table[TBLSIZE];
// Initialize the symbol table with builtin variables
void initTable(void);
// Get the value of a variable
int getval(char *str);
// Set the value of a variable
int setval(char *str, int val);
// Make a new node according to token type and lexeme
BTNode *makeNode(TokenSet tok, const char *lexe);
// Free the syntax tree
void freeTree(BTNode *root);
BTNode *factor(void);
BTNode *assign_expr(void);
BTNode *or_expr(void);
BTNode *xor_expr(void);
BTNode *or_expr_tail(BTNode *left);
BTNode *and_expr(void);
BTNode *xor_expr_tail(BTNode *left);
BTNode *and_expr_tail(BTNode *left);
BTNode *addsub_expr(void);
BTNode *addsub_expr_tail(BTNode *left);
BTNode *muldiv_expr(void);
BTNode *muldiv_expr_tail(BTNode *left);
BTNode *unary_expr(void);
/*
statement := END | assign_expr END
assign_expr := ID ASSIGN assign_expr | or_expr
or_expr := xor_expr or_expr_tail
or_expr_tail := OR xor_expr or_expr_tail | NiL
xor_expr := and_expr xor_expr_tail
xor_expr_tail := XOR and_expr xor_expr_tail | NiL
and_expr := addsub_expr and_expr_tail | NiL
and_expr_tail := AND addsub_expr and_expr_tail | NiL
addsub_expr := muldiv_expr addsub_expr_tail
addsub_expr_tail := ADDSUB muldiv_expr addsub_expr_tail | NiL
muldiv_expr := unary_expr muldiv_expr_tail
muldiv_expr_tail := MULDIV unary_expr muldiv_expr_tail | NiL
unary_expr := ADDSUB unary_expr | factor
factor := INT. | ID. | INCDEC ID. | LPAREN assign_expr RPAREN. //finish?
*/
BTNode *term(void);
BTNode *term_tail(BTNode *left);
BTNode *expr(void);
BTNode *expr_tail(BTNode *left);
void printPrefix(BTNode *root);
void statement(void);
// Print error message and exit the program
// for codeGen
//remember register's position
int r=-1,ok = 0, newone, flag=0;
BTNode *check=NULL;
// Evaluate the syntax tree
void search_div(BTNode *root);
void search_id(BTNode *root);
int evaluate(BTNode *root);
int evaluateTree(BTNode *root,int r);
// Print the syntax tree in prefix
/*============================================================================================
lex implementation
============================================================================================*/
TokenSet getToken(void)
{
int i = 0;
char c = '\0', cc = '\0';
while ((c = fgetc(stdin)) == ' ' || c == '\t');
if (isdigit(c)) {
lexeme[0] = c;
c = fgetc(stdin);
i = 1;
while (isdigit(c) && i < MAXLEN) {
lexeme[i] = c;
++i;
c = fgetc(stdin);
}
ungetc(c, stdin);
lexeme[i] = '\0';
return INT;
} else if (c == '+' || c == '-') {
lexeme[0] = c;
cc=fgetc(stdin);
if((c=='+'&&cc=='+')||(c=='-'&&cc=='-')){
lexeme[1]=c;
lexeme[2]='\0';
return INCDEC;
}
else {
ungetc(cc,stdin);
lexeme[1] = '\0';
return ADDSUB;
}
} else if (c == '*' || c == '/') {
lexeme[0] = c;
lexeme[1] = '\0';
return MULDIV;
} else if (c=='&'){
lexeme[0]=c;
lexeme[1]='\0';
return AND;
} else if (c=='^'){
lexeme[0]=c;
lexeme[1]='\0';
return XOR;
} else if (c=='|'){
lexeme[0]=c;
lexeme[1]='\0';
return OR;
} else if (c == '\n') {
lexeme[0] = '\0';
return END;
} else if (c == '=') {
strcpy(lexeme, "=");
return ASSIGN;
} else if (c == '(') {
strcpy(lexeme, "(");
return LPAREN;
} else if (c == ')') {
strcpy(lexeme, ")");
return RPAREN;
} else if (isalpha(c)) {
lexeme[0] = c;
c = fgetc(stdin);
i = 1;
while (( isalpha(c) || c=='_' ||isdigit(c) )&& i < MAXLEN) {
lexeme[i] = c;
++i;
c = fgetc(stdin);
}
ungetc(c, stdin);
lexeme[i] = '\0';
return ID;
} else if (c == EOF) {
return ENDFILE;
} else {
return UNKNOWN;
}
}
void advance(void) {
curToken = getToken();
}
int match(TokenSet token) {
if (curToken == UNKNOWN)
advance();
return token == curToken;
}
char *getLexeme(void) {
return lexeme;
}
/*============================================================================================
parser implementation
============================================================================================*/
void initTable(void) {
strcpy(table[0].name, "x");
table[0].val = 0;
strcpy(table[1].name, "y");
table[1].val = 0;
strcpy(table[2].name, "z");
table[2].val = 0;
sbcount = 3;
}
int getid(char *str){
for(int i=0;i<sbcount;i++){
if(strcmp(str,table[i].name)==0){
return i;
}
}
printf("EXIT 1\n");
exit(0);
}
int getval(char *str) { //取得ID
int i = 0;
for (i = 0; i < sbcount; i++){
if (strcmp(str, table[i].name) == 0) {
return i*4;
}//有找到的情況
}
if (sbcount >= TBLSIZE) {
printf("EXIT 1\n");exit(0);
}
strcpy(table[sbcount].name, str);//沒找到的情況
table[sbcount].val = 0;
sbcount++;
return sbcount*4-4;
}
int setval(char *str, int val) { //指派值給table
int i = 0;
for (i = 0; i < sbcount; i++) {
if (strcmp(str, table[i].name) == 0) {
table[i].val = val;
return val;
}
}//有找到的情況
if (sbcount >= TBLSIZE) {
printf("EXIT 1\n");exit(0);
}
strcpy(table[sbcount].name, str);//沒找到的情況
table[sbcount].val = val;
sbcount++;
return val;
}
BTNode *makeNode(TokenSet tok, const char *lexe) {
BTNode *node = (BTNode*)malloc(sizeof(BTNode));
strcpy(node->lexeme, lexe);
node->data = tok;
node->val = 0;
node->left = NULL;
node->right = NULL;
return node;
}
void freeTree(BTNode *root) {
if (root != NULL) {
freeTree(root->left);
freeTree(root->right);
free(root);
}
}
/*
statement := END | assign_expr END
assign_expr := ID ASSIGN assign_expr | or_expr
or_expr := xor_expr or_expr_tail
or_expr_tail := OR xor_expr or_expr_tail | NiL
xor_expr := and_expr xor_expr_tail
xor_expr_tail := XOR and_expr xor_expr_tail | NiL
and_expr := addsub_expr and_expr_tail | NiL
and_expr_tail := AND addsub_expr and_expr_tail | NiL
addsub_expr := muldiv_expr addsub_expr_tail
addsub_expr_tail := ADDSUB muldiv_expr addsub_expr_tail | NiL
muldiv_expr := unary_expr muldiv_expr_tail
muldiv_expr_tail := MULDIV unary_expr muldiv_expr_tail | NiL
unary_expr := ADDSUB unary_expr | factor
factor := INT. | ID. | INCDEC ID. | LPAREN assign_expr RPAREN. //finish?
*/
//factor := INT. | ID. | INCDEC ID. | LPAREN assign_expr RPAREN.
BTNode *factor(void) {
BTNode *retp, *left;
if (match(INT)) {
retp = makeNode(INT, getLexeme());
advance();
}
else if (match(ID)) {
left = makeNode(ID, getLexeme());
advance();
retp=left;
}
else if (match(INCDEC)){
retp = makeNode(INCDEC,getLexeme());
advance();
if(match(ID)){
retp->left = makeNode(ID,getLexeme());
advance();
retp->right = makeNode(INT,"1");
}
else {
printf("EXIT 1\n");
exit(0);
}
/////////////////////////////////////
// node(maybe '+', maybe '-') //
// / \ //
// ID 1 //
/////////////////////////////////////
}
else if (match(LPAREN)) {
advance();
retp = assign_expr();
if (match(RPAREN)) advance();
else{
printf("EXIT 1\n");exit(0);
}
}
else {
printf("EXIT 1\n");exit(0);
}
return retp;
}
//assign_expr := ID ASSIGN assign_expr | or_expr
BTNode *assign_expr(void){
BTNode *retp,*left;
retp = or_expr();
if(match(ASSIGN)&&retp->data==ID){
left = retp;
retp = makeNode(ASSIGN,getLexeme());
advance();
retp->left = left;
retp->right = assign_expr();
}
return retp;
}
//or_expr := xor_expr or_expr_tail
BTNode *or_expr(void){
BTNode *retp=xor_expr();
return or_expr_tail(retp);
}
//xor_expr := and_expr xor_expr_tail
BTNode *xor_expr(void){
BTNode *retp=and_expr();
return xor_expr_tail(retp);
}
//or_expr_tail := OR xor_expr or_expr_tail | NiL
BTNode *or_expr_tail(BTNode *left){
BTNode *retp=NULL;
if(match(OR)){
retp = makeNode(OR,getLexeme());
advance();
retp->left=left;
retp->right=xor_expr();
return or_expr_tail(retp);
}else {
return left;
}
}
//xor_expr_tail := XOR and_expr xor_expr_tail | NiL
BTNode *xor_expr_tail(BTNode *left){
BTNode *retp=NULL;
if(match(XOR)){
retp = makeNode(XOR,getLexeme());
advance();
retp->left=left;
retp->right=and_expr();
return xor_expr_tail(retp);
}
else {
return left;
}
}
//and_expr := addsub_expr and_expr_tail
BTNode *and_expr(void){
BTNode *retp=addsub_expr();
return and_expr_tail(retp);
}
//and_expr_tail := AND addsub_expr and_expr_tail | NiL
BTNode *and_expr_tail(BTNode *left){
BTNode *retp=NULL;
if(match(AND)){
retp = makeNode(AND,getLexeme());
advance();
retp->left=left;
retp->right=addsub_expr();
return and_expr_tail(retp);
}
else{
return left;
}
}
//addsub_expr := muldiv_expr addsub_expr_tail
BTNode *addsub_expr(void){
BTNode *retp=muldiv_expr();
return addsub_expr_tail(retp);
}
//addsub_expr_tail := ADDSUB muldiv_expr addsub_expr_tail | NiL
BTNode *addsub_expr_tail(BTNode *left){
BTNode *retp=NULL;
if(match(ADDSUB)){
retp = makeNode(ADDSUB,getLexeme());
advance();
retp->left=left;
retp->right=muldiv_expr();
return addsub_expr_tail(retp);
}
else{
return left;
}
}
//muldiv_expr := unary_expr muldiv_expr_tail
BTNode *muldiv_expr(void){
BTNode *retp=unary_expr();
return muldiv_expr_tail(retp);
}
//muldiv_expr_tail := MULDIV unary_expr muldiv_expr_tail | NiL
BTNode *muldiv_expr_tail(BTNode *left){
BTNode *retp=NULL;
if(match(MULDIV)){
retp = makeNode(MULDIV,getLexeme());
advance();
retp->left=left;
retp->right=unary_expr();
return muldiv_expr_tail(retp);
}
else{
return left;
}
}
//unary_expr := ADDSUB unary_expr | factor
BTNode *unary_expr(void){
BTNode *retp;
if(match(ADDSUB)){
retp = makeNode(ADDSUB,getLexeme());
advance();
retp->left = makeNode(INT,"0");
retp->right = unary_expr();
/////////////////////////////////////
// node(maybe '+', maybe '-') //
// / \ //
// 0 unary_expr() //
/////////////////////////////////////
}
else{
retp = factor();
}
return retp;
}
//statement := END | assign_expr END
void statement(void) {
BTNode *retp = NULL,*tmp;
advance();
if(match(ENDFILE)){
printf("MOV r0 [0]\nMOV r1 [4]\nMOV r2 [8]\nEXIT 0\n");
exit(0);
}
else if (match(END)) {
advance();
} else {
retp = assign_expr();
if (match(END)) {
//printPrefix(retp);
evaluateTree(retp,0);
}
else {
printf("EXIT 1\n");
exit(0);
}
}
}
/*============================================================================================
codeGen implementation
============================================================================================*/
//mark my idea:
//if(ID):= print(MOV reg[k] ID([k]))
//if(int):= print(MOV reg[k] INT([k]))
//if(strcmp(root->lexeme,'+')==0) := print(ADD reg[ki] reg[kj])
//if(strcmp(root->lexeme,'-')==0) := print(SUB reg[ki] reg[kj])
//if(strcmp(root->lexeme,'*')==0) := print(MUL reg[ki] reg[kj])
//if(strcmp(root->lexeme,'/')==0) := print(DIV reg[ki] reg[kj])
//現在我需要的東西:
//利用evaluateTree(root)去把東西印出來
//簡而言之,可以說是不需要把值算出來
/*
void search_div(BTNode *root){
if(root!=NULL){
if(strcmp(root->lexeme,"/")==0) check = root;
else search_div(root->left),search_div(root->right);
}
return;
}
void search_id(BTNode *root){
if(root!=NULL){
if(root->data == ID) ok = 1;
else search_id(root->left),search_id(root->right);
}
return;
}
int evaluate(BTNode *root){
int retval = 0, lv = 0, rv = 0;
if (root != NULL) {
switch (root->data) {
case ID:
for (int i = 0; i < sbcount; i++){
if (strcmp(root->lexeme, table[i].name) == 0) retval = table[i].val;
}
break;
case INT:
retval = atoi(root->lexeme);
break;
case ASSIGN:
rv = evaluate(root->right);
retval = setval(root->left->lexeme, rv);
break;
case ADDSUB:
case MULDIV:
case OR:
case XOR:
case AND:
case INCDEC:
lv = evaluate(root->left);
rv = evaluate(root->right);
if (strcmp(root->lexeme, "+") == 0) {retval = lv + rv;}
else if (strcmp(root->lexeme, "-") == 0) {retval = lv - rv;}
else if (strcmp(root->lexeme, "*") == 0) {retval = lv * rv;}
else if (strcmp(root->lexeme, "|") == 0) {retval = lv | rv;}
else if (strcmp(root->lexeme, "&") == 0) {retval = lv & rv;}
else if (strcmp(root->lexeme, "^") == 0) {retval = lv ^ rv;}
else if (strcmp(root->lexeme, "++") == 0) {retval = lv + 1;}
else if (strcmp(root->lexeme, "--") == 0) {retval = lv - 1;}
else if (strcmp(root->lexeme, "/") == 0) {
retval = lv / rv;
}
break;
default:
retval = 0;
}
}
return retval;
}
*/
int evaluateTree(BTNode *root, int r) {
int retval = 0, ne, tmp, rr, ll;
if (root != NULL) {
switch (root->data) {
case ID:
//找table裡面有沒有存過root->lexeme,如果有就直接用,沒有就創一個新的
//有用過->1,沒出現過->0 //之前印過的就不印了!
newone=getid(root->lexeme);
ne = getval(root->lexeme);
flag=1;
if(r>=8){
strcpy(table[sbcount].name, "\0");//沒找到的情況
table[sbcount].val = 0;
sbcount++;root->ever = sbcount*4-4;
printf("MOV [%d] r%d\n",root->ever,r%8);
}
else root->ever = 0;
printf("MOV r%d [%d]\n",r%8,ne);
break;
case INT:
retval = atoi(root->lexeme);
if(r>=8){
strcpy(table[sbcount].name, "\0");//沒找到的情況
table[sbcount].val = 0;
sbcount++;root->ever = sbcount*4-4;
printf("MOV [%d] r%d\n",root->ever,r%8);
}
else root->ever = 0;
printf("MOV r%d %d\n",r%8,retval);
//把root->lexeme的char值強制轉換成int
break;
case ASSIGN:
rr = evaluateTree(root->right,r);
//利用遞迴,搜尋root右邊的值
retval = setval(root->left->lexeme, rr);
newone=getid(root->left->lexeme);
tmp = getval(root->left->lexeme);
//把左邊的值,交給右邊
root->ever = 0;
printf("MOV [%d] r%d\n",tmp,r%8);
break;
case ADDSUB:
case MULDIV:
case OR:
case XOR:
case AND:
case INCDEC:
ll = evaluateTree(root->left, r);
//先遞迴找左邊
if(strcmp(root->lexeme,"/")==0) flag=0;
rr = evaluateTree(root->right, r+1);
//再遞迴找右邊
if (strcmp(root->lexeme, "+") == 0) {
printf("ADD r%d r%d\n",r%8,(r+1)%8);retval = ll + rr;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme,"++") == 0){
printf("ADD r%d r%d\n",r%8,(r+1)%8);
printf("MOV [%d] r%d\n",getid(root->left->lexeme)*4,r%8);
retval = ll + 1;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme, "-") == 0) {
printf("SUB r%d r%d\n",r%8,(r+1)%8);retval = ll - rr;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme,"--") == 0){
printf("SUB r%d r%d\n",r%8,(r+1)%8);
printf("MOV [%d] r%d\n",getid(root->left->lexeme)*4,r%8);
retval = ll -1;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme, "*") == 0) {
printf("MUL r%d r%d\n",r%8,(r+1)%8);retval = ll * rr;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme, "/") == 0) {
if(rr==0&&!flag){printf("EXIT 1\n");exit(0);}
printf("DIV r%d r%d\n",r%8,(r+1)%8);
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme, "|") == 0 ){
printf("OR r%d r%d\n",r%8,(r+1)%8);retval = ll | rr;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme, "^") == 0 ){
printf("XOR r%d r%d\n",r%8,(r+1)%8);retval = ll ^ rr;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
else if (strcmp(root->lexeme, "&") == 0){
printf("AND r%d r%d\n",r%8,(r+1)%8);retval = ll & rr;
if(root->right->ever != 0) printf("MOV r%d [%d]\n",(r+1)%8,root->right->ever),root->ever = root->left->ever;}
break;
default:
retval = 0;
break;
}
}
return retval;
}
void printPrefix(BTNode *root) {
if (root != NULL) {
printf("%s ", root->lexeme);
printPrefix(root->left);
printPrefix(root->right);
}
}
/*============================================================================================
main
============================================================================================*/
// This package is a calculator
// It works like a Python interpretor
// Example:
// >> y = 2
// >> z = 2
// >> x = 3 * y + 4 / (2 * z)
// It will print the answer of every line
// You should turn it into an expression compiler
// And print the assembly code according to the input
// This is the grammar used in this package
// You can modify it according to the spec and the slide
// statement := ENDFILE | END | expr END
// expr := term expr_tail
// expr_tail := ADDSUB term expr_tail | NiL
// term := factor term_tail
// term_tail := MULDIV factor term_tail| NiL
// factor := INT | ADDSUB INT |
// ID | ADDSUB ID |
// ID ASSIGN expr |
// LPAREN expr RPAREN |
// ADDSUB LPAREN expr RPAREN
int main() {
initTable();
while (1) {
statement();
}
return 0;
}
```