temp.c

/*
 * temp.c - functions to create and manipulate temporary variables which are
 *          used in the IR tree representation before it has been determined
 *          which variables are to go into registers.
 *
 */

#include <stdlib.h>
#include <string.h>

#include "util.h"
#include "symbol.h"
#include "temp.h"
#include "table.h"


struct Temp_temp_ {
    int num;
};

string Temp_labelstring(Temp_label s) {
    return S_name(s);
}

static int labels = 0;

Temp_label Temp_newlabel(void) {
    char buf[100];
    sprintf(buf, "L%d", labels++);
    return Temp_namedlabel(String(buf));
}

/* The label will be created only if it is not found. */
Temp_label Temp_namedlabel(string s) {
    return S_Symbol(s);
}

static int temps = 100;

Temp_temp Temp_newtemp(void) {
    Temp_temp p = (Temp_temp)checked_malloc(sizeof (*p));
    p->num = temps++;
    { 
        char r[16];
        sprintf(r, "t%d", p->num);
        Temp_enter(Temp_name(), p, String(r));
    }
    return p;
}

struct Temp_map_ {
    TAB_table tab; 
    Temp_map under;
};

/* A global `Temp_map<Temp_temp, string>` */
Temp_map Temp_name(void) {
    static Temp_map m = NULL;
    if (!m) 
        m = Temp_empty();
    return m;
}

Temp_map newMap(TAB_table tab, Temp_map under) {
    Temp_map m = checked_malloc(sizeof(*m));

    m->tab = tab;
    m->under = under;

    return m;
}

Temp_map Temp_empty(void) {
    return newMap(TAB_empty(), NULL);
}

Temp_map Temp_layerMap(Temp_map over, Temp_map under) {
    if (over == NULL)
        return under;
    else 
        return newMap(over->tab, Temp_layerMap(over->under, under));
}

void Temp_enter(Temp_map m, Temp_temp t, string s) {
    assert(m && m->tab);
    TAB_enter(m->tab, t, s);
}

string Temp_look(Temp_map m, Temp_temp t) {
    string s;
    assert(m && m->tab);
    s = TAB_look(m->tab, t);
    if (s) 
        return s;
    else if (m->under) 
        return Temp_look(m->under, t);
    else 
        return NULL;
}

Temp_tempList Temp_TempList(Temp_temp h, Temp_tempList t) {
    Temp_tempList p = (Temp_tempList)checked_malloc(sizeof(*p));

    p->head = h; 
    p->tail = t;

    return p;
}

Temp_labelList Temp_LabelList(Temp_label h, Temp_labelList t) {
    Temp_labelList p = (Temp_labelList)checked_malloc(sizeof(*p));

    p->head = h; 
    p->tail = t;

    return p;
}

static FILE *outfile;

void showit(Temp_temp t, string r) {
    fprintf(outfile, "t%d -> %s\n", t->num, r);
}

void Temp_dumpMap(FILE *out, Temp_map m) {
    outfile = out;
    TAB_dump(m->tab,(void (*)(void *, void*))showit);
    if (m->under) {
        fprintf(out,"---------\n");
        Temp_dumpMap(out,m->under);
    }
}