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#include "interpreter.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
typedef void *YY_BUFFER_STATE;
extern FILE *yyin;
extern ASTNode *ast_root;
extern int yyparse(void);
extern void yyrestart (FILE *);
extern YY_BUFFER_STATE yy_scan_string(const char *);
extern void yy_delete_buffer(YY_BUFFER_STATE);
void context_set(hashmap_t context, const char *name, int val) {
hashmap_insert(context, name, val);
}
int context_get(hashmap_t context, const char *name) {
int *val = hashmap_get(context, name);
if (val) return *val;
return 0;
}
static void print_var(const char *name, int val) {
printf("%s = %d\n", name, val);
}
void context_print(hashmap_t context) {
hashmap_iterate(context, print_var);
}
static int eval_aexpr(hashmap_t context, ASTNode *node) {
switch (node->type) {
case NT_INT: return node->u.d_int.val;
case NT_VAR: return context_get(context, node->u.d_var.name);
case NT_AOP: {
int aexp1 = eval_aexpr(context, node->u.d_aop.aexp1);
int aexp2 = eval_aexpr(context, node->u.d_aop.aexp2);
switch (node->u.d_aop.aop) {
case AOP_ADD: return aexp1 + aexp2;
case AOP_SUB: return aexp1 - aexp2;
case AOP_MUL: return aexp1 * aexp2;
}
}
default:
fprintf(stderr, "Bad aexpr node %d\n", node->type);
exit(EXIT_FAILURE);
}
}
static int eval_bexpr(hashmap_t context, ASTNode *node) {
switch (node->type) {
case NT_BOP: {
int bexp1 = eval_bexpr(context, node->u.d_bop.bexp1);
int bexp2 = eval_bexpr(context, node->u.d_bop.bexp2);
switch (node->u.d_bop.bop) {
case BOP_AND: return bexp1 && bexp2;
case BOP_OR: return bexp1 || bexp2;
}
}
case NT_NOT:
return !eval_bexpr(context, node->u.d_not.bexp);
case NT_ROP: {
int aexp1 = eval_aexpr(context, node->u.d_rop.aexp1);
int aexp2 = eval_aexpr(context, node->u.d_rop.aexp2);
switch (node->u.d_rop.rop) {
case ROP_EQ: return aexp1 == aexp2;
case ROP_NE: return aexp1 != aexp2;
case ROP_LT: return aexp1 < aexp2;
case ROP_LE: return aexp1 <= aexp2;
case ROP_GT: return aexp1 > aexp2;
case ROP_GE: return aexp1 >= aexp2;
}
}
default:
fprintf(stderr, "Bad bexpr node %d\n", node->type);
exit(EXIT_FAILURE);
}
}
void exec_stmt(hashmap_t context, ASTNode *node) {
while (node) {
switch (node->type) {
case NT_SKIP:
return;
case NT_ASSIGN: {
char *name = node->u.d_assign.var->u.d_var.name;
int val = eval_aexpr(context, node->u.d_assign.aexp);
context_set(context, name, val);
return;
}
case NT_SEQ:
exec_stmt(context, node->u.d_seq.stm1);
exec_stmt(context, node->u.d_seq.stm2);
return;
case NT_IF:
if (eval_bexpr(context, node->u.d_if.bexp))
exec_stmt(context, node->u.d_if.stm1);
else
exec_stmt(context, node->u.d_if.stm2);
return;
case NT_WHILE:
while (eval_bexpr(context, node->u.d_while.bexp)) {
exec_stmt(context, node->u.d_while.stm);
}
return;
case NT_LET: {
char *name = node->u.d_let.var->u.d_var.name;
int old_val = context_get(context, name);
int new_val = eval_aexpr(context, node->u.d_let.aexp);
context_set(context, name, new_val);
exec_stmt(context, node->u.d_let.stm);
context_set(context, name, old_val);
return;
}
default:
fprintf(stderr, "Bad stmt node %d\n", node->type);
exit(EXIT_FAILURE);
}
}
}
int exec_file (hashmap_t context, const char *path) {
yyin = fopen(path, "r");
if (!yyin) {
perror(path);
return -1;
}
yyrestart(yyin);
if (!yyparse()) {
exec_stmt(context, ast_root);
ast_free(ast_root);
} else {
fprintf(stderr, "Parse error in %s\n", path);
fclose(yyin);
return -1;
}
fclose(yyin);
return 0;
}
int exec_str (hashmap_t context, const char *str) {
YY_BUFFER_STATE buf = yy_scan_string(str);
if (!yyparse()) {
exec_stmt(context, ast_root);
ast_free(ast_root);
} else {
fprintf(stderr, "Parse error\n");
yy_delete_buffer(buf);
return -1;
}
yy_delete_buffer(buf);
return 0;
}
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