Analyze project even if fatal import dir error

Before that fix golangci-lint couldn't run analysis
if in any dir there was go file with corrupted `package` or `import`
statement.
After that fix it will only warn about such files and continue analysis.
But it will fail analysis after finding 10 packages with such errors
to not being too noisy in case of internal error.

Author: jirfag

Diff for: pkg/packages/resolver.go

@@ -21,7 +21,8 @@ type Resolver struct {
 	skippedDirs []string
 	log         logutils.Log
 
-	wd string // working directory
+	wd                  string // working directory
+	importErrorsOccured int    // count of errors because too bad files in packages
 }
 
 func NewResolver(buildTags, excludeDirs []string, log logutils.Log) (*Resolver, error) {
@@ -79,7 +80,7 @@ func (r *Resolver) resolveRecursively(root string, prog *Program) error {
 
 	fis, err := ioutil.ReadDir(root)
 	if err != nil {
-		return fmt.Errorf("can't resolve dir %s: %s", root, err)
+		return fmt.Errorf("can't read dir %s: %s", root, err)
 	}
 	// TODO: pass cached fis to build.Context
 
@@ -113,7 +114,7 @@ func (r *Resolver) resolveRecursively(root string, prog *Program) error {
 	return nil
 }
 
-func (r Resolver) resolveDir(dir string, prog *Program) error {
+func (r *Resolver) resolveDir(dir string, prog *Program) error {
 	// TODO: fork build.Import to reuse AST parsing
 	bp, err := prog.bctx.ImportDir(dir, build.ImportComment|build.IgnoreVendor)
 	if err != nil {
@@ -122,7 +123,14 @@ func (r Resolver) resolveDir(dir string, prog *Program) error {
 			return nil
 		}
 
-		return fmt.Errorf("can't resolve dir %s: %s", dir, err)
+		err = fmt.Errorf("can't import dir %q: %s", dir, err)
+		r.importErrorsOccured++
+		if r.importErrorsOccured >= 10 {
+			return err
+		}
+
+		r.log.Warnf("Can't analyze dir %q: %s", dir, err)
+		return nil
 	}
 
 	pkg := Package{