Fix working with cgo generated files.

getters.go

@@ -10,7 +10,10 @@ import (
 	"strings"
 )
 
-var errEmptyInput = errors.New("empty input")
+var (
+	errEmptyInput      = errors.New("empty input")
+	errUnsuitableInput = errors.New("unsuitable input")
+)
 
 // specialReplacer is a replacer for some types of special lines in comments,
 // which shouldn't be checked. For example, if comment ends with a block of
@@ -44,6 +47,17 @@ func newParsedFile(file *ast.File, fset *token.FileSet) (*parsedFile, error) {
 		return nil, fmt.Errorf("read file: %v", err)
 	}
 
+	// Dirty hack. For some cases Go generates temporary files during
+	// compilation process if there is a cgo block in the source file. Some of
+	// these temporary files are just copies of original source files but with
+	// new generated comments at the top. Because of them the content differs
+	// from AST. For some reason it differs only in golangci-lint. I failed to
+	// find out the exact description of the process, so let's just skip files
+	// generated by cgo.
+	if isCgoGenerated(pf.lines) {
+		return nil, errUnsuitableInput
+	}
+
 	// Check consistency to avoid checking slice indexes in each function
 	lastComment := pf.file.Comments[len(pf.file.Comments)-1]
 	if p := pf.fset.Position(lastComment.End()); len(pf.lines) < p.Line {
@@ -258,3 +272,12 @@ func matchAny(s string, rr []*regexp.Regexp) bool {
 	}
 	return false
 }
+
+func isCgoGenerated(lines []string) bool {
+	for i := range lines {
+		if strings.Contains(lines[i], "Code generated by cmd/cgo") {
+			return true
+		}
+	}
+	return false
+}

getters_test.go

@@ -69,6 +69,26 @@ func TestGetComments(t *testing.T) {
 			}
 		})
 	}
+
+	t.Run("try to get comments from cgo generated file", func(t *testing.T) {
+		testFile := filepath.Join("testdata", "get", "cgo.go")
+		fset := token.NewFileSet()
+		file, err := parser.ParseFile(fset, testFile, nil, parser.ParseComments)
+		if err != nil {
+			t.Fatalf("Failed to parse input file: %v", err)
+		}
+
+		pf, err := newParsedFile(file, fset)
+		if pf != nil {
+			t.Fatalf("Unexpected file content")
+		}
+		if err != errUnsuitableInput {
+			t.Fatalf(
+				"Unexpected error:\n  expected: %v\n       got: %v",
+				errUnsuitableInput, err,
+			)
+		}
+	})
 }
 
 func TestGetText(t *testing.T) {

godot.go

@@ -44,7 +44,7 @@ type comment struct {
 // Run runs this linter on the provided code.
 func Run(file *ast.File, fset *token.FileSet, settings Settings) ([]Issue, error) {
 	pf, err := newParsedFile(file, fset)
-	if err == errEmptyInput {
+	if err == errEmptyInput || err == errUnsuitableInput {
 		return nil, nil
 	}
 	if err != nil {