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#include "interpreter.h"
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include "hashmap.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);
typedef struct Context{
hashmap_t var_table;
hashmap_t proc_table;
} Context;
static ASTNode *context_get_proc(Context *context, const char *name) {
ASTNode **procdecl = (ASTNode**)hashmap_get(context->proc_table, name);
if (procdecl) return *procdecl;
return NULL;
}
static void context_set_proc(Context *context, const char *name, ASTNode *procdecl) {
hashmap_insert(context->proc_table, name, (void*)procdecl);
}
Context *context_create(void) {
Context *context = malloc(sizeof(Context));
assert(context);
context->var_table = hashmap_create();
context->proc_table = hashmap_create();
return context;
}
void context_free(Context *context) {
hashmap_free(context->var_table);
hashmap_keys_iter_t iter = hashmap_keys_iter_create(context->proc_table);
const char *key;
while ((key = hashmap_keys_iter_next(iter)) != NULL) {
ASTNode *procdecl = context_get_proc(context, key);
assert(procdecl);
ast_free(procdecl);
}
hashmap_keys_iter_free(iter);
hashmap_free(context->proc_table);
free(context);
}
int context_get_var(Context *context, const char *name) {
int *val = (int*)hashmap_get(context->var_table, name);
if (val) return *val;
return 0;
}
void context_set_var(Context *context, const char *name, int val) {
hashmap_insert(context->var_table, name, (void*)val);
}
void context_print_var_table(Context *context) {
hashmap_keys_iter_t iter = hashmap_keys_iter_create(context->var_table);
const char *key;
while ((key = hashmap_keys_iter_next(iter)) != NULL) {
int val = context_get_var(context, key);
printf("%s = %d\n", key, val);
}
hashmap_keys_iter_free(iter);
}
static int eval_aexpr(Context *context, ASTNode *node) {
switch (node->type) {
case NT_INT: return node->u.d_int.val;
case NT_VAR: return context_get_var(context, node->u.d_var.name);
case NT_AOP: {
int aexp1_val = eval_aexpr(context, node->u.d_aop.aexp1);
int aexp2_val = eval_aexpr(context, node->u.d_aop.aexp2);
switch (node->u.d_aop.aop) {
case AOP_ADD: return aexp1_val + aexp2_val;
case AOP_SUB: return aexp1_val - aexp2_val;
case AOP_MUL: return aexp1_val * aexp2_val;
default: assert(0);
}
}
default: assert(0);
}
}
static int eval_bexpr(Context *context, ASTNode *node) {
switch (node->type) {
case NT_BOP: {
int bexp1_val = eval_bexpr(context, node->u.d_bop.bexp1);
int bexp2_val = eval_bexpr(context, node->u.d_bop.bexp2);
switch (node->u.d_bop.bop) {
case BOP_AND: return bexp1_val && bexp2_val;
case BOP_OR: return bexp1_val || bexp2_val;
default: assert(0);
}
}
case NT_NOT: return !eval_bexpr(context, node->u.d_not.bexp);
case NT_ROP: {
int aexp1_val = eval_aexpr(context, node->u.d_rop.aexp1);
int aexp2_val = eval_aexpr(context, node->u.d_rop.aexp2);
switch (node->u.d_rop.rop) {
case ROP_EQ: return aexp1_val == aexp2_val;
case ROP_NE: return aexp1_val != aexp2_val;
case ROP_LT: return aexp1_val < aexp2_val;
case ROP_LE: return aexp1_val <= aexp2_val;
case ROP_GT: return aexp1_val > aexp2_val;
case ROP_GE: return aexp1_val >= aexp2_val;
default: assert(0);
}
}
default: assert(0);
}
}
static int interp_proccall(Context *context, ASTNode *node) {
char *name = node->u.d_proccall.name;
ASTNode *procdecl = context_get_proc(context, name);
if (!procdecl) {
fprintf(stderr, "Error: procedure %s not defined\n", name);
return -1;
}
ASTNodeList *caller_args = node->u.d_proccall.args;
ASTNodeList *callee_args = procdecl->u.d_procdecl.args;
Context *proc_context = context_create();
hashmap_keys_iter_t iter = hashmap_keys_iter_create(context->proc_table);
const char *key;
while ((key = hashmap_keys_iter_next(iter)) != NULL) {
ASTNode *proc = context_get_proc(context, key);
context_set_proc(proc_context, key, ast_clone(proc));
}
hashmap_keys_iter_free(iter);
while (caller_args && callee_args) {
char *caller_arg_name = caller_args->node->u.d_var.name;
char *callee_arg_name = callee_args->node->u.d_var.name;
context_set_var(proc_context, callee_arg_name, context_get_var(context, caller_arg_name));
caller_args = caller_args->next;
callee_args = callee_args->next;
}
if (caller_args || callee_args) {
fprintf(stderr, "Error: procedure %s called with wrong number of value arguments\n", name);
context_free(proc_context);
return -1;
}
if (interp_ast(proc_context, procdecl->u.d_procdecl.stm)) {
context_free(proc_context);
return -1;
}
ASTNodeList *caller_vargs = node->u.d_proccall.vargs;
ASTNodeList *callee_vargs = procdecl->u.d_procdecl.vargs;
while (caller_vargs && callee_vargs) {
char *caller_varg_name = caller_vargs->node->u.d_var.name;
char *callee_varg_name = callee_vargs->node->u.d_var.name;
context_set_var(context, caller_varg_name, context_get_var(proc_context, callee_varg_name));
caller_vargs = caller_vargs->next;
callee_vargs = callee_vargs->next;
}
if (caller_vargs || callee_vargs) {
fprintf(stderr, "Error: procedure %s called with wrong number of variable arguments\n", name);
context_free(proc_context);
return -1;
}
context_free(proc_context);
return 0;
}
int interp_ast(Context *context, ASTNode *node) {
switch (node->type) {
case NT_SKIP: return 0;
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_var(context, name, val);
return 0;
}
case NT_SEQ:
if (interp_ast(context, node->u.d_seq.stm1)) return -1;
if (interp_ast(context, node->u.d_seq.stm2)) return -1;
return 0;
case NT_IF:
if (eval_bexpr(context, node->u.d_if.bexp)) return interp_ast(context, node->u.d_if.stm1);
else return interp_ast(context, node->u.d_if.stm2);
case NT_WHILE:
while (eval_bexpr(context, node->u.d_while.bexp)) {
if (interp_ast(context, node->u.d_while.stm)) return -1;
}
return 0;
case NT_LET: {
char *name = node->u.d_let.var->u.d_var.name;
int old_val = context_get_var(context, name);
int new_val = eval_aexpr(context, node->u.d_let.aexp);
context_set_var(context, name, new_val);
int ret = interp_ast(context, node->u.d_let.stm);
context_set_var(context, name, old_val);
return ret;
}
case NT_PROCDECL: {
char *name = node->u.d_procdecl.name;
ASTNode *procdecl_old = context_get_proc(context, name);
if (procdecl_old) {
fprintf(stderr, "Error: procedure %s already defined\n", name);
return -1;
}
ASTNode *procdecl = ast_clone(node);
context_set_proc(context, name, procdecl);
return 0;
}
case NT_PROCCALL: {
return interp_proccall(context, node);
}
default: assert(0);
}
}
int interp_file (Context *context, const char *path) {
yyin = fopen(path, "r");
if (!yyin) {
return -1;
}
yyrestart(yyin);
if (yyparse()) {
ast_free(ast_root);
fclose(yyin);
return -1;
}
if (interp_ast(context, ast_root)) {
ast_free(ast_root);
fclose(yyin);
return -1;
}
ast_free(ast_root);
fclose(yyin);
return 0;
}
int interp_str (Context *context, const char *str) {
YY_BUFFER_STATE buf = yy_scan_string(str);
if (yyparse()) {
ast_free(ast_root);
yy_delete_buffer(buf);
return -1;
}
if (interp_ast(context, ast_root)) {
ast_free(ast_root);
yy_delete_buffer(buf);
return -1;
}
yy_delete_buffer(buf);
return 0;
}
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