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#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, AND, OR, XOR, INC, DEC, ADDSUB_ASSIGN } TokenSet; TokenSet getToken(void); TokenSet curToken = UNKNOWN; char lexeme[MAXLEN]; int inTable(char* str); // 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 #define error(errorNum) { \ if (PRINTERR) \ fprintf(stderr, "error() called at %s:%d: ", __FILE__, __LINE__); \ err(errorNum); \ } // Error types typedef enum { UNDEFINED, MISPAREN, NOTNUMID, NOTFOUND, RUNOUT, NOTLVAL, DIVZERO, SYNTAXERR } ErrorType; // 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; 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); extern BTNode *factor(void); extern BTNode* unary_expr(void); extern BTNode* muldiv_expr_tail(BTNode* left); extern BTNode* muldiv_expr(void); extern BTNode* addsub_expr_tail(BTNode* left); extern BTNode* addsub_expr(void); extern BTNode* and_expr_tail(BTNode* left); extern BTNode* and_expr(void); extern BTNode* xor_expr_tail(BTNode* left); extern BTNode* xor_expr(void); extern BTNode* or_expr_tail(BTNode* left); extern BTNode *or_expr(void); extern BTNode* assign_expr(void); extern void statement(void); // Print error message and exit the program void err(ErrorType errorNum); // for codeGen // Evaluate the syntax tree int evaluateTree(BTNode *root); // Print the syntax tree in prefix void printPrefix(BTNode *root); // Get assembly code of syntax tree int getAssembly(BTNode *root, int r); int flag = 0; /*============================================================================================ lex implementation ============================================================================================*/ TokenSet getToken(void) { int i = 0; char c = '\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 == '-') {//modify lexeme[0] = c; c = fgetc(stdin); if (c == '+') { lexeme[1] = c; lexeme[2] = '\0'; return INC; } else if (c == '-') { lexeme[1] = c; lexeme[2] = '\0'; return DEC; } else if (c == '=') { lexeme[1] = c; lexeme[2] = '\0'; return ADDSUB_ASSIGN; } else{ ungetc(c, stdin); lexeme[1] = '\0'; return ADDSUB; } } else if (c == '*' || c == '/') { lexeme[0] = c; lexeme[1] = '\0'; return MULDIV; } 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) && i < MAXLEN) { lexeme[i] = c; ++i; c = fgetc(stdin); } ungetc(c, stdin); lexeme[i] = '\0'; return ID; } else if (c == '&') {//modify lexeme[0] = c; lexeme[1] = '\0'; return AND; } else if (c == '|') {//modify lexeme[0] = c; lexeme[1] = '\0'; return OR; } else if (c == '^') {//modify lexeme[0] = c; lexeme[1] = '\0'; return XOR; } else if (c == EOF) { return ENDFILE; } else { return UNKNOWN; } } int inTable(char* str) { for (int i = 0;i < sbcount;i++) { if (strcmp(table[i].name, str) == 0) return 1; } return 0; } 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 getval(char *str) { int i = 0; for (i = 0; i < sbcount; i++) { if (strcmp(str, table[i].name) == 0) return table[i].val; } if (sbcount >= TBLSIZE) error(RUNOUT); error(SYNTAXERR); } int getidx(char* str) { int i = 0; for (i = 0; i < sbcount; i++) { if (strcmp(str, table[i].name) == 0) return 4 * i; } //printf("getidx : error\n"); error(SYNTAXERR); return -1; } int setval(char *str, int val) { int i = 0; //printf("setval : %s , %d\n", str, val); for (i = 0; i < sbcount; i++) { if (strcmp(str, table[i].name) == 0) { table[i].val = val; return val; } } if (sbcount >= TBLSIZE) error(RUNOUT); strcpy(table[sbcount].name, str); 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); } } BTNode *factor(void) { BTNode *retp = NULL, *left = NULL; if (match(INT)) { retp = makeNode(INT, getLexeme()); advance(); } else if (match(ID)) { retp = makeNode(ID, getLexeme()); advance(); } else if (match(INC)) { retp = makeNode(INC, getLexeme()); advance(); retp->right = makeNode(INT, "1"); retp->left = factor(); } else if (match(DEC)) { retp = makeNode(DEC, getLexeme()); advance(); retp->right = makeNode(INT, "1"); retp->left = factor(); } else if (match(LPAREN)) { advance(); retp = assign_expr(); if (match(RPAREN)) advance(); else error(MISPAREN); } else { error(NOTNUMID); } return retp; } //BTNode *term(void) { // BTNode *node = factor(); // return term_tail(node); //} //BTNode *term_tail(BTNode *left) { // BTNode *node = NULL; // // if (match(MULDIV)) { // node = makeNode(MULDIV, getLexeme()); // advance(); // node->left = left; // node->right = factor(); // return term_tail(node); // } else { // return left; // } //} //BTNode *expr(void) { // BTNode *node = term(); // return expr_tail(node); //} //BTNode *expr_tail(BTNode *left) { // BTNode *node = NULL; // // if (match(ADDSUB)) { // node = makeNode(ADDSUB, getLexeme()); // advance(); // node->left = left; // node->right = term(); // return expr_tail(node); // } else { // return left; // } //} BTNode* unary_expr(void) { BTNode* node = NULL; if (match(ADDSUB)) { node = makeNode(ADDSUB, getLexeme()); advance(); node->left = makeNode(INT, "0"); node->right = unary_expr(); } else { node = factor(); } return node; } BTNode* muldiv_expr(void) { BTNode* node = unary_expr(); return muldiv_expr_tail(node); } BTNode* muldiv_expr_tail(BTNode* left) { BTNode* node = NULL; if (match(MULDIV)) { node = makeNode(MULDIV, getLexeme()); advance(); node->left = left; node->right = unary_expr(); return muldiv_expr_tail(node); } else { return left; } } BTNode* addsub_expr(void) { BTNode* node = muldiv_expr(); return addsub_expr_tail(node); } BTNode* addsub_expr_tail(BTNode* left) { BTNode* node = NULL; if (match(ADDSUB)) { node = makeNode(ADDSUB, getLexeme()); advance(); node->left = left; node->right = muldiv_expr(); return addsub_expr_tail(node); } else { return left; } } BTNode* and_expr(void) { BTNode* node = addsub_expr(); return and_expr_tail(node); } BTNode* and_expr_tail(BTNode* left) { BTNode* node = NULL; if (match(AND)) { node = makeNode(AND, getLexeme()); advance(); node->left = left; node->right = addsub_expr(); return and_expr_tail(node); } else { return left; } } BTNode* xor_expr(void) { BTNode* node = and_expr(); return xor_expr_tail(node); } BTNode* xor_expr_tail(BTNode* left) { BTNode* node = NULL; if (match(XOR)) { node = makeNode(XOR, getLexeme()); advance(); node->left = left; node->right = and_expr(); return xor_expr_tail(node); } else { return left; } } BTNode* or_expr(void) { BTNode* node = xor_expr(); return or_expr_tail(node); } BTNode* or_expr_tail(BTNode* left) { BTNode* node = NULL; if (match(OR)) { node = makeNode(OR, getLexeme()); advance(); node->left = left; node->right = xor_expr(); return or_expr_tail(node); } else { return left; } } BTNode* assign_expr(void) { BTNode* node = NULL, * left = NULL; left = or_expr(); if (match(ASSIGN)) { if (left->data != ID) error(SYNTAXERR); node = makeNode(ASSIGN, getLexeme()); advance(); node->left = left; node->right = assign_expr(); } else if (match(ADDSUB_ASSIGN)) { if (left->data != ID) error(SYNTAXERR); node = makeNode(ADDSUB_ASSIGN, getLexeme()); advance(); node->left = left; node->right = assign_expr(); } else node = left; return node; } void statement(void) { BTNode *retp = NULL; if (match(ENDFILE)) { printf("MOV r0 [0]\nMOV r1 [4]\nMOV r2 [8]\n"); printf("EXIT 0\n"); exit(0); } else if (match(END)) { //printf(">> "); advance(); } else { retp = assign_expr(); if (match(END)) { int k = evaluateTree(retp); int d = getAssembly(retp, 0); //printf("Prefix traversal: "); //printPrefix(retp); //printf("\n"); freeTree(retp); //printf(">> "); advance(); } else { error(SYNTAXERR); } } } void err(ErrorType errorNum) { if (PRINTERR) { printf("EXIT 1\n"); fprintf(stderr, "error: "); switch (errorNum) { case MISPAREN: fprintf(stderr, "mismatched parenthesis\n"); break; case NOTNUMID: fprintf(stderr, "number or identifier expected\n"); break; case NOTFOUND: fprintf(stderr, "variable not defined\n"); break; case RUNOUT: fprintf(stderr, "out of memory\n"); break; case NOTLVAL: fprintf(stderr, "lvalue required as an operand\n"); break; case DIVZERO: fprintf(stderr, "divide by constant zero\n"); break; case SYNTAXERR: fprintf(stderr, "syntax error\n"); break; default: fprintf(stderr, "undefined error\n"); break; } } exit(0); } /*============================================================================================ codeGen implementation ============================================================================================*/ int getAssembly(BTNode *root, int r) { if (root != NULL) { int num, reg1, reg2; switch (root->data) { case ID: printf("MOV r%d [%d]\n", r, getidx(root->lexeme)); break; case INT: num = atoi(root->lexeme); printf("MOV r%d %d\n", r, num); break; case ASSIGN: reg1 = getAssembly(root->right, r); printf("MOV [%d] r%d\n", getidx(root->left->lexeme), reg1); break; case AND: reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("AND r%d r%d\n", reg1, reg2); break; case OR: reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("OR r%d r%d\n", reg1, reg2); break; case XOR: reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("XOR r%d r%d\n", reg1, reg2); break; case INC: reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("ADD r%d r%d\n", reg1, reg2); printf("MOV [%d] r%d\n", getidx(root->left->lexeme), r); break; case DEC: reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("SUB r%d r%d\n", reg1, reg2); printf("MOV [%d] r%d\n", getidx(root->left->lexeme), r); break; case ADDSUB_ASSIGN: if (strcmp(root->lexeme, "+=") == 0) { reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r+1); printf("ADD r%d r%d\n", reg1, reg2); printf("MOV [%d] r%d\n", getidx(root->left->lexeme), r); break; }else if (strcmp(root->lexeme, "-=") == 0) { reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("SUB r%d r%d\n", reg1, reg2); printf("MOV [%d] r%d\n", getidx(root->left->lexeme), r); break; } case ADDSUB: case MULDIV: if (strcmp(root->lexeme, "+") == 0) { reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("ADD r%d r%d\n", reg1, reg2); break; }else if (strcmp(root->lexeme, "-") == 0) { reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("SUB r%d r%d\n", reg1, reg2); break; } else if (strcmp(root->lexeme, "*") == 0) { reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("MUL r%d r%d\n", reg1, reg2); break; } else if (strcmp(root->lexeme, "/") == 0) { reg1 = getAssembly(root->left, r); reg2 = getAssembly(root->right, r + 1); printf("DIV r%d r%d\n", reg1, reg2); break; } default: r = 0; } } return r; } int evaluateTree(BTNode *root) { int retval = 0, lv = 0, rv = 0; if (root != NULL) { switch (root->data) { case ID: flag = 1; retval = getval(root->lexeme); break; case INT: retval = atoi(root->lexeme); break; case ASSIGN: flag = 1; rv = evaluateTree(root->right); retval = setval(root->left->lexeme, rv); break; case AND: lv = evaluateTree(root->left); rv = evaluateTree(root->right); retval = lv & rv; break; case OR: lv = evaluateTree(root->left); rv = evaluateTree(root->right); retval = lv | rv; break; case XOR: lv = evaluateTree(root->left); rv = evaluateTree(root->right); retval = lv ^ rv; break; case INC: flag = 1; rv = evaluateTree(root->right); retval = rv + 1; break; case DEC: flag = 1; rv = evaluateTree(root->right); retval = rv - 1; break; case ADDSUB_ASSIGN: lv = evaluateTree(root->left); rv = evaluateTree(root->right); retval = setval(root->left->lexeme, lv+rv); break; case ADDSUB: case MULDIV: lv = evaluateTree(root->left); flag = 0; rv = evaluateTree(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) { if (rv == 0){ //printf("flag : %d\n", flag); if (flag) break; else error(DIVZERO); }else{ retval = lv / rv; } } break; default: retval = 0; } } 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(); //printf(">> "); while (1) { statement(); } return 0; }
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