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#include "interpreter.h"
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
static int eval_aexpr(IMP_InterpreterContext *context, const IMP_ASTNode *node) {
switch (node->type) {
case IMP_AST_NT_INT: return node->data.integer.val;
case IMP_AST_NT_VAR: return imp_interpreter_context_var_get(context, node->data.variable.name);
case IMP_AST_NT_AOP: {
int l_val = eval_aexpr(context, node->data.arith_op.l_aexpr);
int r_val = eval_aexpr(context, node->data.arith_op.r_aexpr);
switch (node->data.arith_op.aopr) {
case IMP_AST_AOP_ADD: return l_val + r_val;
case IMP_AST_AOP_SUB: return l_val - r_val;
case IMP_AST_AOP_MUL: return l_val * r_val;
default: assert(0);
}
}
default: assert(0);
}
}
static int eval_bexpr(IMP_InterpreterContext *context, const IMP_ASTNode *node) {
switch (node->type) {
case IMP_AST_NT_BOP: {
int l_val = eval_bexpr(context, node->data.bool_op.l_bexpr);
int r_val = eval_bexpr(context, node->data.bool_op.r_bexpr);
switch (node->data.bool_op.bopr) {
case IMP_AST_BOP_AND: return l_val && r_val;
case IMP_AST_BOP_OR: return l_val || r_val;
default: assert(0);
}
}
case IMP_AST_NT_NOT: return !eval_bexpr(context, node->data.bool_not.bexpr);
case IMP_AST_NT_ROP: {
int l_val = eval_aexpr(context, node->data.rel_op.l_aexpr);
int r_val = eval_aexpr(context, node->data.rel_op.r_aexpr);
switch (node->data.rel_op.ropr) {
case IMP_AST_ROP_EQ: return l_val == r_val;
case IMP_AST_ROP_NE: return l_val != r_val;
case IMP_AST_ROP_LT: return l_val < r_val;
case IMP_AST_ROP_LE: return l_val <= r_val;
case IMP_AST_ROP_GT: return l_val > r_val;
case IMP_AST_ROP_GE: return l_val >= r_val;
default: assert(0);
}
}
default: assert(0);
}
}
static int interpret_proccall(IMP_InterpreterContext *context, const IMP_ASTNode *node) {
const char *name = node->data.proc_call.name;
const IMP_ASTNode *procdecl = imp_interpreter_context_proc_get(context, name);
if (!procdecl) {
fprintf(stderr, "Error: procedure %s not defined\n", name);
return -1;
}
IMP_InterpreterContext *proc_context = imp_interpreter_context_create();
IMP_InterpreterContextProcIter *proc_iter = imp_interpreter_context_proc_iter_create(context);
const IMP_InterpreterContextProcTableEntry *proc_entry;
while ((proc_entry = imp_interpreter_context_proc_iter_next(proc_iter))) {
imp_interpreter_context_proc_set(proc_context, proc_entry->key, proc_entry->value);
}
imp_interpreter_context_proc_iter_destroy(proc_iter);
IMP_ASTNodeList *caller_val_args = node->data.proc_call.val_args;
IMP_ASTNodeList *callee_val_args = procdecl->data.proc_decl.val_args;
while (caller_val_args && callee_val_args) {
int val = eval_aexpr(context, caller_val_args->node);
const char *callee_arg_name = callee_val_args->node->data.variable.name;
imp_interpreter_context_var_set(proc_context, callee_arg_name, val);
caller_val_args = caller_val_args->next;
callee_val_args = callee_val_args->next;
}
if (caller_val_args || callee_val_args) {
fprintf(stderr, "Error: procedure %s called with wrong number of value arguments\n", name);
imp_interpreter_context_destroy(proc_context);
return -1;
}
if (imp_interpreter_interpret_ast(proc_context, procdecl->data.proc_decl.body_stmt)) {
imp_interpreter_context_destroy(proc_context);
return -1;
}
IMP_ASTNodeList *caller_var_args = node->data.proc_call.var_args;
IMP_ASTNodeList *callee_var_args = procdecl->data.proc_decl.var_args;
while (caller_var_args && callee_var_args) {
const char *caller_varg_name = caller_var_args->node->data.variable.name;
const char *callee_varg_name = callee_var_args->node->data.variable.name;
imp_interpreter_context_var_set(context, caller_varg_name, imp_interpreter_context_var_get(proc_context, callee_varg_name));
caller_var_args = caller_var_args->next;
callee_var_args = callee_var_args->next;
}
if (caller_var_args || callee_var_args) {
fprintf(stderr, "Error: procedure %s called with wrong number of variable arguments\n", name);
imp_interpreter_context_destroy(proc_context);
return -1;
}
imp_interpreter_context_destroy(proc_context);
return 0;
}
int imp_interpreter_interpret_ast(IMP_InterpreterContext *context, const IMP_ASTNode *node) {
switch (node->type) {
case IMP_AST_NT_SKIP: return 0;
case IMP_AST_NT_ASSIGN: {
const char *name = node->data.assign.var->data.variable.name;
int val = eval_aexpr(context, node->data.assign.aexpr);
imp_interpreter_context_var_set(context, name, val);
return 0;
}
case IMP_AST_NT_SEQ:
if (imp_interpreter_interpret_ast(context, node->data.seq.fst_stmt)) return -1;
if (imp_interpreter_interpret_ast(context, node->data.seq.snd_stmt)) return -1;
return 0;
case IMP_AST_NT_IF:
if (eval_bexpr(context, node->data.if_stmt.cond_bexpr)) return imp_interpreter_interpret_ast(context, node->data.if_stmt.then_stmt);
else return imp_interpreter_interpret_ast(context, node->data.if_stmt.else_stmt);
case IMP_AST_NT_WHILE:
while (eval_bexpr(context, node->data.while_stmt.cond_bexpr)) {
if (imp_interpreter_interpret_ast(context, node->data.while_stmt.body_stmt)) return -1;
}
return 0;
case IMP_AST_NT_LET: {
const char *name = node->data.let_stmt.var->data.variable.name;
int old_val = imp_interpreter_context_var_get(context, name);
int new_val = eval_aexpr(context, node->data.let_stmt.aexpr);
imp_interpreter_context_var_set(context, name, new_val);
int ret = imp_interpreter_interpret_ast(context, node->data.let_stmt.body_stmt);
imp_interpreter_context_var_set(context, name, old_val);
return ret;
}
case IMP_AST_NT_PROCDECL: {
const char *name = node->data.proc_decl.name;
if (imp_interpreter_context_proc_get(context, name)) {
fprintf(stderr, "Error: procedure %s already defined\n", name);
return -1;
}
imp_interpreter_context_proc_set(context, name, node);
return 0;
}
case IMP_AST_NT_PROCCALL: {
return interpret_proccall(context, node);
}
default: assert(0);
}
}
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