update README; rename main.go

1 files changed, 174 insertions, 0 deletions

diff --git a/goosebumps.go b/goosebumps.go
new file mode 100644
index 0000000..a0f522f
--- /dev/null
+++ b/goosebumps.go
@@ -0,0 +1,174 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"io/fs"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"golang.org/x/mod/modfile"
+)
+
+var (
+	dir      = flag.String("d", ".", "directory with go.mod file")
+	recurse  = flag.Bool("r", false, "recursively search for go.mod files")
+	cache    = flag.String("modcache", getmodcache(), "location of go mod cache")
+	excheckm = flag.String("exempt", "golang.org", "domains exempt from the search, seperated by space")
+
+	checkInit   = flag.Bool("ci", false, "check for implementations of init()")
+	checkUnsafe = flag.Bool("cu", false, "check for imports of unsafe")
+	checkCgo    = flag.Bool("cc", false, "check for imports of cgo")
+	checkPprof  = flag.Bool("cp", false, "check for imports of net/http/pprof")
+
+	exceptions []string
+
+	relcache string
+)
+
+func getmodcache() string {
+	if c := os.Getenv("GOMODCACHE"); c != "" {
+		return c
+	} else if c = os.Getenv("GOPATH"); c != "" {
+		return c + "/pkg/mod"
+	} else {
+		return os.Getenv("HOME") + "/pkg/mod"
+	}
+
+}
+
+func main() {
+	flag.Parse()
+
+	exceptions = strings.Fields(*excheckm)
+	relcache = strings.Replace(*cache, os.Getenv("HOME"), "~", 1)
+
+	if !(*checkInit || *checkUnsafe || *checkCgo || *checkPprof) {
+		fmt.Println("Nothing to check. Use -ci|-cu|-cc|-cp")
+		return
+	}
+
+	if !*recurse {
+		file := filepath.Join(*dir, "go.mod")
+		singleFile(file)
+		return
+	}
+
+	recursive(*dir)
+}
+
+func singleFile(file string) {
+	data, err := os.ReadFile(file)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	mf, err := modfile.Parse(file, data, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(len(mf.Require))
+	pathcache := map[string]bool{}
+	for _, r := range mf.Require {
+		path := strings.Join(r.Syntax.Token, "@")
+		if _, done := pathcache[path]; done {
+			continue
+		}
+		pathcache[path] = true
+		go func() {
+			defer wg.Done()
+			checkPath(*cache + "/" + path)
+		}()
+	}
+
+	wg.Wait()
+}
+
+func recursive(dir string) {
+	filepath.WalkDir(dir, func(p string, info fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		} else if info.IsDir() {
+			return nil
+		} else if "go.mod" == filepath.Base(p) {
+			fmt.Printf("analyzing %s\n", p)
+			singleFile(p)
+		}
+		return nil
+	})
+}
+
+func isExempt(path string) bool {
+	for _, pattern := range exceptions {
+		if strings.Contains(path, pattern) {
+			return true
+		}
+	}
+	return false
+}
+
+func modpath(filename string) string {
+	return filepath.Join(relcache, strings.TrimPrefix(filename, *cache+"/"))
+}
+
+func checkPath(path string) {
+	var fset = token.NewFileSet()
+
+	filter := func(inf fs.FileInfo) bool {
+		return !strings.HasSuffix(inf.Name(), "_test.go")
+	}
+
+	filepath.WalkDir(path, func(p string, info fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		} else if !info.IsDir() {
+			return nil
+		} else if isExempt(p) {
+			return nil
+		}
+
+		pkgs, err := parser.ParseDir(fset, p, filter, parser.Mode(0))
+		if err != nil {
+			return err
+		}
+
+		for _, pkg := range pkgs {
+			for filename, file := range pkg.Files {
+				if *checkUnsafe || *checkCgo || *checkPprof {
+					for _, imp := range file.Imports {
+						if *checkUnsafe && imp.Path.Value == `"unsafe"` {
+							fmt.Println("unsafe in", modpath(filename))
+						} else if *checkCgo && imp.Path.Value == `"C"` {
+							fmt.Println("cgo    in", modpath(filename))
+						} else if *checkPprof && imp.Path.Value == `"net/http/pprof"` {
+							fmt.Println("pprof  in", modpath(filename))
+						}
+					}
+				}
+
+				if !*checkInit {
+					break
+				}
+			INIT:
+				for _, decl := range file.Decls {
+					if f, ok := decl.(*ast.FuncDecl); ok {
+						if f.Name.Name == "init" {
+							fmt.Println("init   in", modpath(filename))
+							break INIT
+						}
+					}
+				}
+			}
+		}
+
+		return nil
+	})
+}