preprocess_c.cpp

/*
 * Copyright (c) 2018-2020, High Performance Computing Architecture and System
 * research laboratory at University of North Carolina at Charlotte (HPCAS@UNCC)
 * and Lawrence Livermore National Security, LLC.
 *
 * SPDX-License-Identifier: (BSD-3-Clause)
 */

#include <iostream>
#include <regex>
#include <fstream>

std::vector<std::string>* preProcessC(std::ifstream&);

std::vector<std::string>* preProcessC(std::ifstream& input_file) {

    std::string input_pragma;
    int total_amount = 0;
    int line_no = 0;
    int current_pragma_line_no = 1;
    std::vector<std::string> *omp_pragmas = new std::vector<std::string>();

    char current_char = input_file.peek();
    std::string current_line;
    std::regex c_regex ("^([[:blank:]]*#pragma)([[:blank:]]+)(omp)[[:blank:]]+(.*)");
    std::regex comment_regex ("[/][*]([^*]|[*][^/])*[*][/]");
    std::regex continue_regex ("([\\\\]+[[:blank:]]*$)");

    while (!input_file.eof()) {
        line_no += 1;
        switch (current_char) {
            case '\n':
                input_file.seekg(1, std::ios_base::cur);
                break;
            default:
                std::getline(input_file, current_line);
                // remove the inline comments
                current_line = std::regex_replace(current_line, comment_regex, "");
                input_pragma = "";
                if (std::regex_match(current_line, c_regex)) {
                    // combine continuous lines if necessary
                    while (std::regex_search(current_line, continue_regex)) {
                        // remove the slash part at the end
                        current_line = std::regex_replace(current_line, continue_regex, "");
                        // add the current line to the pragma string
                        input_pragma += current_line;
                        // get the next line
                        std::getline(input_file, current_line);
                        // remove the inline comments of next line
                        current_line = std::regex_replace(current_line, comment_regex, "");
                    };
                    input_pragma += current_line;
                    total_amount += 1;
                    current_pragma_line_no = line_no;
                    //std::cout << input_pragma << std::endl;
                    omp_pragmas->push_back(input_pragma);
                }
        };
        current_char = input_file.peek();
    };

    return omp_pragmas;
}