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#include "lie.h"
#define RETURNSTACK_LEN 200
#define VAR_LEN 1000
static struct { strtype name; objtype type; } type_stack[VAR_LEN];
static objtype return_type[RETURNSTACK_LEN];
static int return_pt, var_pt;
static objtype last_type(symblst s)
{ if (s==NULL) return VOID;
while (s->next!=NULL) s=s->next;
return s->type;
}
static void add_var(strtype name,objtype type)
{
if (var_pt>=VAR_LEN)
error("Number of variables (%ld) exceeded.\n",(long)VAR_LEN);
type_stack[var_pt].name=name;
type_stack[var_pt++].type=type;
}
static void push_type(symblst list)
{
for ( ; list!=NULL; list=list->next) add_var(list->formal,list->type);
}
static objtype type_var(strtype name)
{ int i=var_pt-1;
for (i=var_pt-1; i>=0; --i)
if (type_stack[i].name==name) return type_stack[i].type;
{ symblst foundsym=srchsym(topsym,name,NULL);
if (foundsym==NULL || foundsym->class!=VALUE) return ERROR;
return foundsym->type;
}
}
static void check_function_args(symblst sym,symblst foundsym)
{ symblst f,s;
for (f=foundsym->arglst, s=sym->arglst; f!=NULL && s!=NULL;
f=f->next,s=s->next)
if (isfuntype(f) && s->class != BLOCK)
error("%s is not a user defined function. \n"
,name_tab[s->a.label->name]);
}
static void check_var_type(strtype name,objtype type)
{
int i; objtype old_type;
if (type==UNKNOWN) return; /* assume all is well in this case */
for (i=var_pt-1; i>=0; --i)
if (type_stack[i].name==name)
{ old_type=type_stack[i].type; goto found; }
{ symblst foundsym=srchsym(topsym,name,NULL);
add_var(name,type); /* add local variable, whether or not found */
if (foundsym==NULL) return;
old_type=foundsym->type;
}
found:
if (block_depth==0)
{ if (i>=0) type_stack[i].type=type; } /* change type */
else
if (!eq_types(type,old_type))
error("Illegal type change for %s: %s -> %s,\n"
,name_tab[name],code_obj_type(old_type),code_obj_type(type));
}
extern fobject seqfun;
void init_loop_gettype(void) { var_pt=return_pt=0; }
objtype eval_type(symblst s)
{
symblst t=s->arglst; strtype name=s->a.label->name;
labeltp label0=label;
label=s->a.label;
for (; t!=NULL; t=t->next)
{ if (t->type==UNKNOWN)
{ if (eval_type(t)==UNKNOWN && name_tab[name][0]!='.') return UNKNOWN;
if (t->a.label!=NULL && t->a.label!=label_null
&& t->a.label->name==return_name)
{ if (return_pt==RETURNSTACK_LEN) error("Too many happy returns:\n");
return_type[return_pt++]=t->type;
}
}
}
label=label0; /* restore |label| after handling arguments */
{
symblst foundsym; strtype name=s->a.label->name;
if (s->type!=UNKNOWN) return s->type;
if (name==0) error("System error: eval_type0: no_name.\n");
if (name==seq_name)
{ s->class=MAP; s->data.f=seqfun; return s->type=last_type(s->arglst); }
if (s->class==BLOCK)
{ int var_pt0=var_pt; ++block_depth; push_type(s->arglst);
s->type=eval_type(s->data.expr);
var_pt=var_pt0; --block_depth;
return s->type;
}
{ objtype type;
if (s->arglst==NULL && (type=type_var(name))!=ERROR)
{ s->class=DUMMY; return s->type=type; }
}
{ if ((foundsym=srchsym(symbol_tab[name],name,s->arglst))==NULL)
foundsym=srchsym(topsym, name, s->arglst);
if (foundsym==NULL) error_not_foundsym(s);
check_function_args(s,foundsym);
assignsym(s,foundsym); /* set |s->class| and |s->type| */
if (s->class==OPERATOR) s->data.expr=foundsym; /* save binding found */
}
if (name==assign_name || name==assign_loc_name)
{ symblst lhs=s->arglst, rhs=lhs->next;
strtype varname=lhs->a.label->name; /* name of left hand side */
if (rhs->type==VOID)
error("You cannot assign a %s value.\n", code_obj_type(VOID));
if (name==assign_loc_name)
{ if (block_depth==0) error
("'loc %s= .. ' can only be used inside functions/blocks.\n"
,name_tab[varname]);
add_var(varname, rhs->type);
}
else check_var_type(varname,rhs->type);
return s->type=VOID;
}
if (name==if_name)
{ symblst then_part=s->arglst->next, else_part=then_part->next;
if (else_part==NULL) return s->type=VOID;
if (!eq_types(then_part->type,else_part->type)
&& then_part->type!=UNKNOWN && else_part->type!=UNKNOWN)
error("Type mismatch between branches of if-clause: %s and %s.\n"
,code_obj_type(then_part->type), code_obj_type(else_part->type));
return s->type=
then_part->type!=UNKNOWN ? then_part->type : else_part->type;
}
if (s->type==ARGTYPE)
{ if ((s->type=last_type(s->arglst))!=UNKNOWN) return s->type; }
if (s->class==FUNCTION)
{ int var_pt0=var_pt, return_pt0=return_pt;
strtype fun_name_old=fun_name;
{ fun_name=foundsym->a.name;
++block_depth;
assignnames(s, foundsym->arglst);
push_type(s->arglst);
}
{ s->data.expr=load_function_body(foundsym->data.func);
foundsym->class=FUNCTION_COPIED;
s->type= eval_type(s->data.expr);
foundsym->class=FUNCTION;
s->class=BLOCK;
}
{ int i;
for (i=return_pt0; i<return_pt; ++i)
if (!eq_types(return_type[i],s->type)
&& return_type[i]!=UNKNOWN && s->type!=UNKNOWN) break;
else if (s->type==UNKNOWN) s->type=return_type[i];
if (i<return_pt)
{ Printf("Inconsistent return types for %s:\n",name_tab[name]);
for (i=return_pt0; i<return_pt; ++i)
Printf("return nr.%d has type: %s,\n"
, i-return_pt+1, code_obj_type(return_type[i]));
error("function body has type: %s\n",code_obj_type(s->type));
}
if (s->type==UNKNOWN)
error("The result of function %s has indeterminate type.\n"
,name_tab[name]);
}
{ var_pt=var_pt0;
return_pt=return_pt0;
fun_name=fun_name_old;
--block_depth;
}
return s->type;
}
return s->type; /* if |s->class==FUNCTION_COPIED|, this is |UNKNOWN| */
}
}
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