Load AST for fast linters in different way.

Use build.Import instead of manual parser.ParseFile and paths traversal. It allows:
1. support build tags for all linters.
2. analyze files only for current GOOS/GOARCH: less false-positives.
3. analyze xtest packages (*_test) by golint: upstream golint and
gometalinter can't do it! And don't break analysis on the first xtest
package like it was before.
4. proper handling of xtest packages for linters like goconst where
package boundary is important: less false-positives is expected.

Also:
1. reuse AST parsing for golint and goconst: minor speedup.
2. allow to specify path (not only name) regexp for --skip-files and
--skip-dirs
3. add more default exclude filters for golint about commits:
`(comment on exported (method|function)|should have( a package)?
    comment|comment should be of the form)`
4. print skipped dir in verbose (-v) mode
5. refactor per-linter tests: declare arguments in comments, run only
one linter and in combination with slow linter

Author: jirfag

.golangci.example.yml

@@ -6,9 +6,11 @@ run:
   build-tags:
     - mytag
   skip-dirs:
-    - external_libs
+    - src/external_libs
+    - autogenerated_by_my_lib
   skip-files:
     - ".*\\.pb\\.go$"
+    - lib/bad.go
 
 output:
   format: colored-line-number

Gopkg.lock

@@ -3,8 +3,7 @@ test:
 	golangci-lint run -v
 	golangci-lint run --fast --no-config -v
 	golangci-lint run --no-config -v
-	golangci-lint run --fast --no-config -v ./test/testdata/typecheck.go
-	go test -v -race ./...
+	go test -v ./...
 
 assets:
 	svg-term --cast=183662 --out docs/demo.svg --window --width 110 --height 30 --from 2000 --to 20000 --profile Dracula --term iterm2

Makefile

@@ -235,14 +235,14 @@ Flags:
       --print-issued-lines          Print lines of code with issue (default true)
       --print-linter-name           Print linter name in issue line (default true)
       --issues-exit-code int        Exit code when issues were found (default 1)
-      --build-tags strings          Build tags (not all linters support them)
+      --build-tags strings          Build tags
       --deadline duration           Deadline for total work (default 1m0s)
       --tests                       Analyze tests (*_test.go) (default true)
       --print-resources-usage       Print avg and max memory usage of golangci-lint and total time
   -c, --config PATH                 Read config from file path PATH
       --no-config                   Don't read config
-      --skip-dirs strings           Regexps of directory names to skip
-      --skip-files strings          Regexps of file names to skip
+      --skip-dirs strings           Regexps of directories to skip
+      --skip-files strings          Regexps of files to skip
   -E, --enable strings              Enable specific linter
   -D, --disable strings             Disable specific linter
       --enable-all                  Enable all linters
@@ -255,7 +255,7 @@ Flags:
                                       - Error return value of .((os\.)?std(out|err)\..*|.*Close|.*Flush|os\.Remove(All)?|.*printf?|os\.(Un)?Setenv). is not checked
                                     
                                       # golint: Annoying issue about not having a comment. The rare codebase has such comments
-                                      - (should have comment|comment on exported method|should have a package comment)
+                                      - (comment on exported (method|function)|should have( a package)? comment|comment should be of the form)
                                     
                                       # golint: False positive when tests are defined in package 'test'
                                       - func name will be used as test\.Test.* by other packages, and that stutters; consider calling this

README.md

@@ -65,14 +65,14 @@ func initFlagSet(fs *pflag.FlagSet, cfg *config.Config) {
 	rc := &cfg.Run
 	fs.IntVar(&rc.ExitCodeIfIssuesFound, "issues-exit-code",
 		1, wh("Exit code when issues were found"))
-	fs.StringSliceVar(&rc.BuildTags, "build-tags", nil, wh("Build tags (not all linters support them)"))
+	fs.StringSliceVar(&rc.BuildTags, "build-tags", nil, wh("Build tags"))
 	fs.DurationVar(&rc.Deadline, "deadline", time.Minute, wh("Deadline for total work"))
 	fs.BoolVar(&rc.AnalyzeTests, "tests", true, wh("Analyze tests (*_test.go)"))
 	fs.BoolVar(&rc.PrintResourcesUsage, "print-resources-usage", false, wh("Print avg and max memory usage of golangci-lint and total time"))
 	fs.StringVarP(&rc.Config, "config", "c", "", wh("Read config from file path `PATH`"))
 	fs.BoolVar(&rc.NoConfig, "no-config", false, wh("Don't read config"))
-	fs.StringSliceVar(&rc.SkipDirs, "skip-dirs", nil, wh("Regexps of directory names to skip"))
-	fs.StringSliceVar(&rc.SkipFiles, "skip-files", nil, wh("Regexps of file names to skip"))
+	fs.StringSliceVar(&rc.SkipDirs, "skip-dirs", nil, wh("Regexps of directories to skip"))
+	fs.StringSliceVar(&rc.SkipFiles, "skip-files", nil, wh("Regexps of files to skip"))
 
 	// Linters settings config
 	lsc := &cfg.LintersSettings

pkg/commands/run.go

@@ -28,7 +28,7 @@ var DefaultExcludePatterns = []ExcludePattern{
 		Why:     "Almost all programs ignore errors on these functions and in most cases it's ok",
 	},
 	{
-		Pattern: "(should have comment|comment on exported method|should have a package comment)",
+		Pattern: "(comment on exported (method|function)|should have( a package)? comment|comment should be of the form)",
 		Linter:  "golint",
 		Why:     "Annoying issue about not having a comment. The rare codebase has such comments",
 	},

pkg/config/config.go

@@ -1,139 +1,9 @@
 package fsutils
 
 import (
-	"context"
-	"fmt"
-	"go/build"
 	"os"
-	"path"
-	"path/filepath"
-	"strings"
-	"time"
-
-	"github.com/sirupsen/logrus"
 )
 
-var stdExcludeDirRegexps = []string{
-	"^vendor$", "^third_party$",
-	"^testdata$", "^examples$",
-	"^Godeps$",
-	"^builtin$",
-}
-
-func GetProjectRoot() string {
-	return path.Join(build.Default.GOPATH, "src", "github.com", "golangci", "golangci-worker")
-}
-
-type ProjectPaths struct {
-	Files     []string
-	Dirs      []string
-	IsDirsRun bool
-}
-
-func (p ProjectPaths) MixedPaths() []string {
-	if p.IsDirsRun {
-		return p.Dirs
-	}
-
-	return p.Files
-}
-
-func (p ProjectPaths) FilesGrouppedByDirs() [][]string {
-	dirToFiles := map[string][]string{}
-	for _, f := range p.Files {
-		dir := filepath.Dir(f)
-		dirToFiles[dir] = append(dirToFiles[dir], f)
-	}
-
-	ret := [][]string{}
-	for _, files := range dirToFiles {
-		ret = append(ret, files)
-	}
-	return ret
-}
-
-func processPaths(root string, paths []string, maxPaths int) ([]string, error) {
-	if len(paths) > maxPaths {
-		logrus.Warnf("Gofmt: got too much paths (%d), analyze first %d", len(paths), maxPaths)
-		paths = paths[:maxPaths]
-	}
-
-	ret := []string{}
-	for _, p := range paths {
-		if !filepath.IsAbs(p) {
-			ret = append(ret, p)
-			continue
-		}
-
-		relPath, err := filepath.Rel(root, p)
-		if err != nil {
-			return nil, fmt.Errorf("can't get relative path for path %s and root %s: %s",
-				p, root, err)
-		}
-		ret = append(ret, relPath)
-	}
-
-	return ret, nil
-}
-
-func processResolvedPaths(paths *PathResolveResult) (*ProjectPaths, error) {
-	root, err := os.Getwd()
-	if err != nil {
-		return nil, fmt.Errorf("can't get working dir: %s", err)
-	}
-
-	files, err := processPaths(root, paths.Files(), 10000)
-	if err != nil {
-		return nil, fmt.Errorf("can't process resolved files: %s", err)
-	}
-
-	dirs, err := processPaths(root, paths.Dirs(), 1000)
-	if err != nil {
-		return nil, fmt.Errorf("can't process resolved dirs: %s", err)
-	}
-
-	for i := range dirs {
-		dir := dirs[i]
-		if dir != "." && !filepath.IsAbs(dir) {
-			dirs[i] = "./" + dir
-		}
-	}
-
-	return &ProjectPaths{
-		Files:     files,
-		Dirs:      dirs,
-		IsDirsRun: len(dirs) != 0,
-	}, nil
-}
-
-func GetPathsForAnalysis(ctx context.Context, inputPaths []string, includeTests bool, skipDirRegexps []string) (ret *ProjectPaths, err error) {
-	defer func(startedAt time.Time) {
-		if ret != nil {
-			logrus.Infof("Found paths for analysis for %s: %s", time.Since(startedAt), ret.MixedPaths())
-		}
-	}(time.Now())
-
-	for _, path := range inputPaths {
-		if strings.HasSuffix(path, ".go") && len(inputPaths) != 1 {
-			return nil, fmt.Errorf("specific files for analysis are allowed only if one file is set")
-		}
-	}
-
-	// TODO: don't analyze skipped files also, when be able to do it
-	excludeDirs := append([]string{}, stdExcludeDirRegexps...)
-	excludeDirs = append(excludeDirs, skipDirRegexps...)
-	pr, err := NewPathResolver(excludeDirs, []string{".go"}, includeTests)
-	if err != nil {
-		return nil, fmt.Errorf("can't make path resolver: %s", err)
-	}
-	paths, err := pr.Resolve(inputPaths...)
-	if err != nil {
-		return nil, fmt.Errorf("can't resolve paths %v: %s", inputPaths, err)
-	}
-
-	return processResolvedPaths(paths)
-}
-
 func IsDir(filename string) bool {
 	fi, err := os.Stat(filename)
 	return err == nil && fi.IsDir()