Fix #126: fix working with symlinks

pkg/fsutils/fsutils.go

@@ -4,22 +4,82 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sync"
 )
 
 func IsDir(filename string) bool {
 	fi, err := os.Stat(filename)
 	return err == nil && fi.IsDir()
 }
 
+var cachedWd string
+var cachedWdError error
+var getWdOnce sync.Once
+var useCache = true
+
+func UseWdCache(use bool) {
+	useCache = use
+}
+
+func Getwd() (string, error) {
+	if !useCache { // for tests
+		return os.Getwd()
+	}
+
+	getWdOnce.Do(func() {
+		cachedWd, cachedWdError = os.Getwd()
+		if cachedWdError != nil {
+			return
+		}
+
+		evaledWd, err := EvalSymlinks(cachedWd)
+		if err != nil {
+			cachedWd, cachedWdError = "", fmt.Errorf("can't eval symlinks on wd %s: %s", cachedWd, err)
+			return
+		}
+
+		cachedWd = evaledWd
+	})
+
+	return cachedWd, cachedWdError
+}
+
+var evalSymlinkCache sync.Map
+
+type evalSymlinkRes struct {
+	path string
+	err  error
+}
+
+func EvalSymlinks(path string) (string, error) {
+	r, ok := evalSymlinkCache.Load(path)
+	if ok {
+		er := r.(evalSymlinkRes)
+		return er.path, er.err
+	}
+
+	var er evalSymlinkRes
+	er.path, er.err = filepath.EvalSymlinks(path)
+	evalSymlinkCache.Store(path, er)
+
+	return er.path, er.err
+}
+
 func ShortestRelPath(path string, wd string) (string, error) {
 	if wd == "" { // get it if user don't have cached working dir
 		var err error
-		wd, err = os.Getwd()
+		wd, err = Getwd()
 		if err != nil {
 			return "", fmt.Errorf("can't get working directory: %s", err)
 		}
 	}
 
+	evaledPath, err := EvalSymlinks(path)
+	if err != nil {
+		return "", fmt.Errorf("can't eval symlinks for path %s: %s", path, err)
+	}
+	path = evaledPath
+
 	// make path absolute and then relative to be able to fix this case:
 	// we'are in /test dir, we want to normalize ../test, and have file file.go in this dir;
 	// it must have normalized path file.go, not ../test/file.go,

pkg/golinters/govet.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/goutils"
 	"github.com/golangci/golangci-lint/pkg/lint/linter"
 	"github.com/golangci/golangci-lint/pkg/logutils"
@@ -82,7 +83,7 @@ func (g Govet) runOnInstalledPackages(ctx context.Context, lintCtx *linter.Conte
 			continue
 		}
 		issues, err := govetAPI.Analyze(astFiles, fset, nil,
-			lintCtx.Settings().Govet.CheckShadowing)
+			lintCtx.Settings().Govet.CheckShadowing, getPath)
 		if err != nil {
 			return nil, err
 		}
@@ -238,7 +239,7 @@ func (g Govet) runOnSourcePackages(_ context.Context, lintCtx *linter.Context) (
 
 		filteredFiles := filterFiles(pkg.Files, lintCtx.Program.Fset)
 		issues, err := govetAPI.Analyze(filteredFiles, lintCtx.Program.Fset, pkg,
-			lintCtx.Settings().Govet.CheckShadowing)
+			lintCtx.Settings().Govet.CheckShadowing, getPath)
 		if err != nil {
 			return nil, err
 		}
@@ -247,3 +248,7 @@ func (g Govet) runOnSourcePackages(_ context.Context, lintCtx *linter.Context) (
 
 	return govetIssues, nil
 }
+
+func getPath(f *ast.File, fset *token.FileSet) (string, error) {
+	return fsutils.ShortestRelPath(fset.Position(f.Pos()).Filename, "")
+}

pkg/goutils/goutils.go

@@ -6,6 +6,8 @@ import (
 	"os/exec"
 	"strings"
 	"sync"
+
+	"github.com/golangci/golangci-lint/pkg/fsutils"
 )
 
 var discoverGoRootOnce sync.Once
@@ -40,7 +42,7 @@ func InGoRoot() (bool, error) {
 		return false, err
 	}
 
-	wd, err := os.Getwd()
+	wd, err := fsutils.Getwd()
 	if err != nil {
 		return false, err
 	}

pkg/lint/astcache/astcache.go

@@ -1,13 +1,12 @@
 package astcache
 
 import (
-	"fmt"
 	"go/ast"
 	"go/parser"
 	"go/token"
-	"os"
 	"path/filepath"
 
+	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/logutils"
 	"golang.org/x/tools/go/loader"
 )
@@ -65,27 +64,18 @@ func (c *Cache) prepareValidFiles() {
 func LoadFromProgram(prog *loader.Program, log logutils.Log) (*Cache, error) {
 	c := NewCache(log)
 
-	root, err := os.Getwd()
-	if err != nil {
-		return nil, fmt.Errorf("can't get working dir: %s", err)
-	}
-
 	for _, pkg := range prog.InitialPackages() {
 		for _, f := range pkg.Files {
 			pos := prog.Fset.Position(f.Pos())
 			if pos.Filename == "" {
 				continue
 			}
 
-			path := pos.Filename
-			if filepath.IsAbs(path) {
-				relPath, err := filepath.Rel(root, pos.Filename)
-				if err != nil {
-					c.log.Warnf("Can't get relative path for %s and %s: %s",
-						root, pos.Filename, err)
-					continue
-				}
-				path = relPath
+			path, err := fsutils.ShortestRelPath(pos.Filename, "")
+			if err != nil {
+				c.log.Warnf("Can't get relative path for %s: %s",
+					pos.Filename, err)
+				continue
 			}
 
 			c.m[path] = &File{

pkg/lint/load.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/goutils"
 	"github.com/golangci/golangci-lint/pkg/logutils"
 
@@ -49,21 +50,13 @@ func isSSAReprNeeded(linters []linter.Config) bool {
 }
 
 func normalizePaths(paths []string) ([]string, error) {
-	root, err := os.Getwd()
-	if err != nil {
-		return nil, fmt.Errorf("can't get working dir: %s", err)
-	}
-
 	ret := make([]string, 0, len(paths))
 	for _, p := range paths {
-		if filepath.IsAbs(p) {
-			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)
-			}
-			p = relPath
+		relPath, err := fsutils.ShortestRelPath(p, "")
+		if err != nil {
+			return nil, fmt.Errorf("can't get relative path for path %s: %s", p, err)
 		}
+		p = relPath
 
 		ret = append(ret, "./"+p)
 	}
@@ -77,7 +70,7 @@ func getCurrentProjectImportPath() (string, error) {
 		return "", fmt.Errorf("no GOPATH env variable")
 	}
 
-	wd, err := os.Getwd()
+	wd, err := fsutils.Getwd()
 	if err != nil {
 		return "", fmt.Errorf("can't get workind directory: %s", err)
 	}

pkg/packages/resolver.go

@@ -36,7 +36,7 @@ func NewResolver(buildTags, excludeDirs []string, log logutils.Log) (*Resolver,
 		excludeDirsMap[dir] = re
 	}
 
-	wd, err := os.Getwd()
+	wd, err := fsutils.Getwd()
 	if err != nil {
 		return nil, fmt.Errorf("can't get working dir: %s", err)
 	}

pkg/packages/resolver_test.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/packages"
 	"github.com/stretchr/testify/assert"
@@ -31,7 +32,7 @@ func prepareFS(t *testing.T, paths ...string) *fsPreparer {
 	root, err := ioutil.TempDir("/tmp", "golangci.test.path_resolver")
 	assert.NoError(t, err)
 
-	prevWD, err := os.Getwd()
+	prevWD, err := fsutils.Getwd()
 	assert.NoError(t, err)
 
 	err = os.Chdir(root)
@@ -243,6 +244,7 @@ func TestPathResolverCommonCases(t *testing.T) {
 		},
 	}
 
+	fsutils.UseWdCache(false)
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			fp := prepareFS(t, tc.prepare...)

pkg/result/processors/path_prettifier.go

@@ -2,9 +2,9 @@ package processors
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
 
+	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
@@ -15,7 +15,7 @@ type PathPrettifier struct {
 var _ Processor = PathPrettifier{}
 
 func NewPathPrettifier() *PathPrettifier {
-	root, err := os.Getwd()
+	root, err := fsutils.Getwd()
 	if err != nil {
 		panic(fmt.Sprintf("Can't get working dir: %s", err))
 	}
@@ -34,7 +34,7 @@ func (p PathPrettifier) Process(issues []result.Issue) ([]result.Issue, error) {
 			return i
 		}
 
-		rel, err := filepath.Rel(p.root, i.FilePath())
+		rel, err := fsutils.ShortestRelPath(i.FilePath(), "")
 		if err != nil {
 			return i
 		}