tool to find reverse Xmas tree declarations in a source tree

rxmastree.go

/*
 * rxmastree - tool to find reverse Xmas tree declarations in a source tree
 * Copyright (C) 2019 Matteo Croce <[email protected]>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

var (
	minTreeSize *int
	maxEqLines  *int
)

func scanFile(path string, _ os.FileInfo, _ error) error {
	if !strings.HasSuffix(path, ".c") && !strings.HasSuffix(path, ".h") {
		return nil
	}

	file, err := os.Open(path)
	if err != nil {
		return err
	}
	defer file.Close()

	var last, eqlines int
	tree := []string{}

	for scanner, i := bufio.NewScanner(file), 1; scanner.Scan(); i++ {
		line := scanner.Text()
		newlen := len(line)
		switch {
		case newlen == 0:
			if len(tree) >= *minTreeSize {
				fmt.Printf("%s:%d tree size %d\n", path, i-len(tree), len(tree))
				for _, l := range tree {
					fmt.Println(l)
				}
				fmt.Println()
			}
			tree = []string{}
		case line[newlen-1] == ';' && newlen < last:
			last = newlen
			tree = append(tree, line)
			eqlines = 0
		case line[newlen-1] == ';' && newlen == last:
			eqlines++
			if eqlines == *maxEqLines {
				eqlines = 0
				last = 0
				tree = tree[:0]
				break
			}
			last = newlen
			tree = append(tree, line)
		case line[newlen-1] == ';':
			eqlines = 0
			last = newlen
			tree = []string{line}
		default:
			eqlines = 0
			last = 0
			tree = tree[:0]
		}
	}

	return nil
}

func main() {
	minTreeSize = flag.Int("minTreeSize", 10, "Minimum tree size")
	maxEqLines = flag.Int("maxEqLines", 3, "maximum number of consecutive equal lines")
	flag.Usage = func() {
		fmt.Println("usage:", os.Args[0], "dir1", "dir2", "...")
		flag.PrintDefaults()
		os.Exit(0)
	}
	flag.Parse()

	if flag.NArg() == 0 {
		flag.Usage()
	}
	for _, p := range flag.Args() {
		if err := filepath.Walk(p, scanFile); err != nil {
			panic(err)
		}
	}
}