bp.cpp

#include "bp.hpp"

#include <iostream>
#include <sstream>
#include <vector>

#include "ralloc.hpp"
#include "symbolTable.hpp"

extern int yylineno;

using namespace std;

bool replace(string& str, const string& from, const string& to, const BranchLabelIndex index);

CodeBuffer::CodeBuffer() : buffer(), globalDefs() {}

CodeBuffer& CodeBuffer::instance() {
    static CodeBuffer inst;  // only instance
    return inst;
}

string CodeBuffer::genLabel(const string& prefix) {
    std::stringstream label;
    if (prefix != "") {
        label << prefix << "_label_";
    } else {
        label << "label_";
    }
    label << buffer.size();
    std::string ret(label.str());
    label << ":";
    emit("br label %" + ret, true);
    emit(label.str());
    return ret;
}

extern SymbolTable symbolTable;

int CodeBuffer::emit(const string& s, bool canSkip) {
    int indentationDepth = symbolTable.getCurrentScopeDepth();
    string indentationStr(indentationDepth, '\t');
    // Skip both this and prev emit start with br
    if (canSkip and s.substr(0, 9) == "br label " and (buffer.back().find("br ") != string::npos or buffer.back().find("ret ") != string::npos)) {
        return -1;
    }

    buffer.push_back(indentationStr + s + " ; " + to_string(yylineno));
    return buffer.size() - 1;
}

void CodeBuffer::bpatch(vector<pair<int, BranchLabelIndex>>& address_list, const std::string& label) {
    for (vector<pair<int, BranchLabelIndex>>::const_iterator i = address_list.begin(); i != address_list.end(); i++) {
        int address = (*i).first;
        if (address == -1) {
            continue;
        }
        BranchLabelIndex labelIndex = (*i).second;
        replace(buffer[address], "@", "%" + label, labelIndex);
    }
    address_list.clear();
}

void CodeBuffer::bpatch(pair<int, BranchLabelIndex> pair, const std::string& label) {
    int address = pair.first;
    BranchLabelIndex labelIndex = pair.second;
    replace(buffer[address], "@", "%" + label, labelIndex);
}

void CodeBuffer::printCodeBuffer() {
    for (std::vector<string>::const_iterator it = buffer.begin(); it != buffer.end(); ++it) {
        // Check if "label @" in in *it
        if (it->find("label @") == string::npos) {
            cout << *it << endl;
        } else {
            cout << "; DEBUG: removed> " << *it << endl;
        }
    }
}

vector<pair<int, BranchLabelIndex>> CodeBuffer::makelist(pair<int, BranchLabelIndex> item) {
    vector<pair<int, BranchLabelIndex>> newList;
    newList.push_back(item);
    return newList;
}

vector<pair<int, BranchLabelIndex>> CodeBuffer::merge(const vector<pair<int, BranchLabelIndex>>& l1, const vector<pair<int, BranchLabelIndex>>& l2) {
    vector<pair<int, BranchLabelIndex>> newList(l1.begin(), l1.end());
    newList.insert(newList.end(), l2.begin(), l2.end());
    return newList;
}

// ******** Methods to handle the global section ********** //
void CodeBuffer::emitGlobal(const std::string& dataLine) {
    globalDefs.push_back(dataLine);
}

void CodeBuffer::printGlobalBuffer() {
    for (vector<string>::const_iterator it = globalDefs.begin(); it != globalDefs.end(); ++it) {
        cout << *it << endl;
    }
}

// ******** Helper Methods ********** //
bool replace(string& str, const string& from, const string& to, const BranchLabelIndex index) {
    size_t pos;
    if (index == SECOND) {
        pos = str.find_last_of(from);
    } else {  // FIRST
        pos = str.find_first_of(from);
    }
    if (pos == string::npos)
        return false;
    str.replace(pos, from.length(), to);
    return true;
}