label.c

/* 
 * Copyright 2019 Yuxuan Xiao

 * Permission is hereby granted, free of charge, to any person obtaining 
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation the 
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 
 * sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in all 
 * copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE 
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"
#include "symbol.h"
#include "label.h"
#define DEFAULT_COUNT_SIZE 10

static string BBNAME = "<entry>";
static string DEFAULT_LABEL = "<label>";
static int labelTag = 0;
static int level = 0;
static S_table LOCAL_TABLE;

string count2string(int count) {
    string s = checked_malloc(DEFAULT_COUNT_SIZE);
    memset(s, 0, DEFAULT_COUNT_SIZE);
    int offset = 0;
    while (count) {
        *(s + offset) = (char)((count % 10) + 48);
        count /= 10;
    }
    return s;
}

void Label_InitTable() {
    LOCAL_TABLE = S_NewTable(FALSE);
}

string Label_NewFun(S_symbol name, void * value) {
    labelTag = 0;
    assert(!level);
    S_Enter(LOCAL_TABLE, name, value);
    S_BeginScope(LOCAL_TABLE);
    level++;
    return BBNAME;
}

void Label_EndFun() {
    S_EndScope(LOCAL_TABLE);
    level--;
    assert(!level);
}

string Label_NewLabel(string prefix) {
    if (!prefix) {
        prefix = DEFAULT_LABEL;
    }
    string tag = count2string(labelTag++);
    int prefixlen = strlen(prefix);
    int taglen = strlen(tag);
    int size = prefixlen + taglen + 1;
    string out = checked_malloc(size);
    memcpy(out, prefix, prefixlen);
    memcpy(out + prefixlen, tag, taglen);
    free(tag);
    return out;
}

void Label_NewDec(S_symbol name, void * value) {
    S_Enter(LOCAL_TABLE, name, value);
}

void * Label_FindDec(S_symbol name) {
    return S_Find(LOCAL_TABLE, name);
}

void Label_NewScope() {
    level++;
    S_BeginScope(LOCAL_TABLE);
}

void Label_EndScope() {
    S_EndScope(LOCAL_TABLE);
    level--;
}