fix: add go.mod hash to the cache salt (#5739)

Author: ldez

Diff for: pkg/commands/run.go

@@ -21,10 +21,12 @@ import (
 
 	"github.com/fatih/color"
 	"github.com/gofrs/flock"
+	"github.com/ldez/grignotin/goenv"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
 	"go.uber.org/automaxprocs/maxprocs"
+	"golang.org/x/mod/sumdb/dirhash"
 	"gopkg.in/yaml.v3"
 
 	"github.com/golangci/golangci-lint/v2/internal/cache"
@@ -216,7 +218,7 @@ func (c *runCommand) preRunE(_ *cobra.Command, args []string) error {
 
 	c.contextBuilder = lint.NewContextBuilder(c.cfg, pkgLoader, pkgCache, guard)
 
-	if err = initHashSalt(c.buildInfo.Version, c.cfg); err != nil {
+	if err = initHashSalt(c.log.Child(logutils.DebugKeyGoModSalt), c.buildInfo.Version, c.cfg); err != nil {
 		return fmt.Errorf("failed to init hash salt: %w", err)
 	}
 
@@ -618,7 +620,7 @@ func formatMemory(memBytes uint64) string {
 
 // Related to cache.
 
-func initHashSalt(version string, cfg *config.Config) error {
+func initHashSalt(logger logutils.Log, version string, cfg *config.Config) error {
 	binSalt, err := computeBinarySalt(version)
 	if err != nil {
 		return fmt.Errorf("failed to calculate binary salt: %w", err)
@@ -629,9 +631,18 @@ func initHashSalt(version string, cfg *config.Config) error {
 		return fmt.Errorf("failed to calculate config salt: %w", err)
 	}
 
+	goModSalt, err := computeGoModSalt()
+	if err != nil {
+		// NOTE: missing go.mod must be ignored.
+		logger.Warnf("Failed to calculate go.mod salt: %v", err)
+	}
+
 	b := bytes.NewBuffer(binSalt)
 	b.Write(configSalt)
+	b.WriteString(goModSalt)
+
 	cache.SetSalt(b)
+
 	return nil
 }
 
@@ -648,15 +659,19 @@ func computeBinarySalt(version string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	f, err := os.Open(p)
 	if err != nil {
 		return nil, err
 	}
+
 	defer f.Close()
+
 	h := sha256.New()
 	if _, err := io.Copy(h, f); err != nil {
 		return nil, err
 	}
+
 	return h.Sum(nil), nil
 }
 
@@ -678,5 +693,29 @@ func computeConfigSalt(cfg *config.Config) ([]byte, error) {
 	if _, err := h.Write(configData.Bytes()); err != nil {
 		return nil, err
 	}
+
 	return h.Sum(nil), nil
 }
+
+func computeGoModSalt() (string, error) {
+	values, err := goenv.Get(context.Background(), goenv.GOMOD)
+	if err != nil {
+		return "", fmt.Errorf("failed to get goenv: %w", err)
+	}
+
+	goModPath := filepath.Clean(values[goenv.GOMOD])
+
+	data, err := os.ReadFile(goModPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to read go.mod: %w", err)
+	}
+
+	sum, err := dirhash.Hash1([]string{goModPath}, func(string) (io.ReadCloser, error) {
+		return io.NopCloser(bytes.NewReader(data)), nil
+	})
+	if err != nil {
+		return "", fmt.Errorf("failed to compute go.sum: %w", err)
+	}
+
+	return sum, nil
+}

Diff for: pkg/config/config.go

@@ -13,6 +13,8 @@ import (
 	"github.com/ldez/grignotin/goenv"
 	"github.com/ldez/grignotin/gomod"
 	"golang.org/x/mod/modfile"
+
+	"github.com/golangci/golangci-lint/v2/pkg/logutils"
 )
 
 // defaultGoVersion the value should be "oldstable" - 1.
@@ -102,16 +104,16 @@ func IsGoGreaterThanOrEqual(current, limit string) bool {
 	return v1.GreaterThanOrEqual(l)
 }
 
-func detectGoVersion(ctx context.Context) string {
-	return cmp.Or(detectGoVersionFromGoMod(ctx), defaultGoVersion)
+func detectGoVersion(ctx context.Context, log logutils.Log) string {
+	return cmp.Or(detectGoVersionFromGoMod(ctx, log), defaultGoVersion)
 }
 
 // detectGoVersionFromGoMod tries to get Go version from go.mod.
 // It returns `toolchain` version if present,
 // else it returns `go` version if present,
 // else it returns `GOVERSION` version if present,
 // else it returns empty.
-func detectGoVersionFromGoMod(ctx context.Context) string {
+func detectGoVersionFromGoMod(ctx context.Context, log logutils.Log) string {
 	values, err := goenv.Get(ctx, goenv.GOMOD, goenv.GOVERSION)
 	if err != nil {
 		values = map[string]string{
@@ -128,6 +130,10 @@ func detectGoVersionFromGoMod(ctx context.Context) string {
 		return parseGoVersion(values[goenv.GOVERSION])
 	}
 
+	if file.Module != nil {
+		log.Infof("Module name %q", file.Module.Mod.Path)
+	}
+
 	// The toolchain exists only if 'toolchain' version > 'go' version.
 	// If 'toolchain' version <= 'go' version, `go mod tidy` will remove 'toolchain' version from go.mod.
 	if file.Toolchain != nil && file.Toolchain.Name != "" {

Diff for: pkg/config/loader.go

@@ -161,7 +161,7 @@ func (l *Loader) checkConfigurationVersion() error {
 
 func (l *Loader) handleGoVersion() {
 	if l.cfg.Run.Go == "" {
-		l.cfg.Run.Go = detectGoVersion(context.Background())
+		l.cfg.Run.Go = detectGoVersion(context.Background(), l.log)
 	}
 
 	l.cfg.Linters.Settings.Govet.Go = l.cfg.Run.Go

Diff for: pkg/logutils/logutils.go

@@ -17,6 +17,7 @@ const envDebug = "GL_DEBUG"
 
 const (
 	DebugKeyBinSalt          = "bin_salt"
+	DebugKeyGoModSalt        = "gomod_salt"
 	DebugKeyConfigReader     = "config_reader"
 	DebugKeyEmpty            = ""
 	DebugKeyEnabledLinters   = "enabled_linters"