static struct expty transVar(Tr_level level, Tr_exp breakk, S_table venv, S_table tenv, A_var v) {
if (!v) {return expTy(Tr_noExp(), Ty_Void());}
/*!those several var is ugly*/
E_enventry x;
struct expty et,et2;
Ty_fieldList fl;
Tr_exp trans;
switch (v->kind) {
case A_simpleVar:/* var id (a)*/
x = S_look(venv, v->u.simple);
trans = Tr_noExp();
if (x && x->kind == E_varEntry) {
trans = Tr_simpleVar(x->u.var.access, level);
return expTy(trans, actual_ty(x->u.var.ty));
} else {
EM_error(v->pos, "undefined var %s", S_name(v->u.simple));
return expTy(trans, Ty_Int());
}
break;
case A_fieldVar:/* var record (a.b)*/
et = transVar(level, breakk, venv, tenv, v->u.field.var);
trans = Tr_noExp();
if (et.ty->kind != Ty_record) {
EM_error(v->pos, "not a record type");
} else {
int i = 0;
for (fl = et.ty->u.record; fl; fl = fl->tail, i++) { /*fl is Ty_fieldList*/
if (fl->head->name == v->u.field.sym) {
trans = Tr_fieldVar(et.exp, i);
return expTy(trans, actual_ty(fl->head->ty));
}
}
EM_error(v->pos, "no such field in record %s", S_name(v->u.field.sym));
}
return expTy(trans, Ty_Int());
break;
case A_subscriptVar: /*var array (a[b])*/
et = transVar(level, breakk, venv, tenv, v->u.subscript.var);
trans = Tr_noExp();
if (et.ty->kind != Ty_array) {
EM_error(v->pos, "not a array type");
} else {
et2 = transExp(level, breakk, venv, tenv, v->u.subscript.exp);
if (et2.ty->kind != Ty_int) {
EM_error(v->pos, "int required");
} else {
trans = Tr_subscriptVar(et.exp, et2.exp);
return expTy(trans, actual_ty(et.ty->u.array));
}
}
return expTy(trans, Ty_Int());
default:
assert(0);
}
}
struct expty transVar_subscriptVar(Tr_level level, S_table venv, S_table tenv, A_var v, Temp_label breakk) {
struct expty var = transVar(level, venv, tenv, v->u.subscript.var, breakk);
struct expty sub = transExp(level, venv, tenv, v->u.subscript.exp, breakk);
if (var.ty->kind != Ty_array) {
EM_error(v->u.subscript.var->pos, "variable type '%s' is not array",
type_msg(var.ty));
return expTy(NULL, Ty_Int());
}
if (sub.ty->kind != Ty_int) {
EM_error(v->u.subscript.exp->pos, "invalid types '%s' for array subscript",
type_msg(sub.ty));
return expTy(NULL, Ty_Int());
}
return expTy(Tr_subscriptVar(var.exp, sub.exp, level),
actual_ty(var.ty->u.array));
}
static struct expty transVar(Tr_level level,Tr_exp breakk, S_table venv,S_table tenv,A_var v){
if (!v) {
return expTy(Tr_noExp(), Ty_Void());
}
E_enventry x;
struct expty et,et2;
Ty_fieldList fl;
Tr_exp trans;
switch(v->kind){
case A_simpleVar: /*var id*/
x=S_look(venv,v->u.simple);
trans = Tr_noExp();
if (x&&x->kind==E_varEntry){
trans= Tr_simpleVar(x->u.var.access, level);
return expTy(trans,actual_ty(x->u.var.ty));
}else{
//变量未定义
EM_error(v->pos, "undefined var %s", S_name(v->u.simple));
return expTy(trans, Ty_Int());
}
break;
case A_fieldVar:/* a.b a.b.c*/
//得到 a 的type 是 record还是 array还是 simplevar
et=transVar(level,breakk,venv,tenv,v->u.field.var);
trans = Tr_noExp();
if (et.ty->kind!=Ty_record)
{
EM_error(v->pos, "not a record type");
return expTy(NULL, Ty_Record(NULL));
}else{
int i=0;
for (fl = et.ty->u.record;fl;fl=fl->tail,i++)
{
//地址比较
if (fl->head->name==v->u.field.sym)
{
trans = Tr_fieldVar(et.exp,i);
return expTy(trans, actual_ty(fl->head->ty));
}
}
EM_error(v->pos, "no such field in record %s", S_name(v->u.field.sym));
}
return expTy(trans, Ty_Int());
break;
case A_subscriptVar:/*a[i]*/
et = transVar(level,breakk,venv, tenv, v->u.subscript.var);
trans = Tr_noExp();
if (et.ty->kind!=Ty_array){
EM_error(v->pos, "not a array type");
}else{
et2=transExp(level,breakk,venv,tenv,v->u.subscript.exp);
if (et2.ty->kind != Ty_int) {
EM_error(v->pos, "int required");
}else{
trans = Tr_subscriptVar(et.exp, et2.exp);
return expTy(trans, actual_ty(et.ty->u.array));
}
}
return expTy(trans, Ty_Int());
break;
}
}
