internal/lsp: allow fine-grained control over vet checks

This change adds an "experimentalDisabledAnalyses" configuration
to the "gopls" configuration. A user can specify a list of excluded
analyses by analyzer name.

Fixes golang/go#31717

Change-Id: I4b162fcd61ecfcef5c926bd0e96f182748a7721d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/179920
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>

internal/lsp/diagnostics.go

@@ -28,7 +28,7 @@ func (s *Server) Diagnostics(ctx context.Context, v source.View, uri span.URI) {
 	if !ok {
 		return
 	}
-	reports, err := source.Diagnostics(ctx, v, gof)
+	reports, err := source.Diagnostics(ctx, v, gof, s.disabledAnalyses)
 	if err != nil {
 		s.session.Logger().Errorf(ctx, "failed to compute diagnostics for %s: %v", gof.URI(), err)
 		return

internal/lsp/general.go

@@ -188,6 +188,15 @@ func (s *Server) processConfig(view source.View, config interface{}) error {
 	if noDocsOnHover, ok := c["noDocsOnHover"].(bool); ok {
 		s.noDocsOnHover = noDocsOnHover
 	}
+	// Check if the user has explicitly disabled any analyses.
+	if disabledAnalyses, ok := c["experimentalDisabledAnalyses"].([]interface{}); ok {
+		s.disabledAnalyses = make(map[string]struct{})
+		for _, a := range disabledAnalyses {
+			if a, ok := a.(string); ok {
+				s.disabledAnalyses[a] = struct{}{}
+			}
+		}
+	}
 	return nil
 }
 

internal/lsp/lsp_test.go

@@ -68,7 +68,7 @@ func (r *runner) Diagnostics(t *testing.T, data tests.Diagnostics) {
 		if !ok {
 			t.Fatalf("%s is not a Go file: %v", uri, err)
 		}
-		results, err := source.Diagnostics(context.Background(), v, gof)
+		results, err := source.Diagnostics(context.Background(), v, gof, nil)
 		if err != nil {
 			t.Fatal(err)
 		}

internal/lsp/server.go

@@ -79,6 +79,7 @@ type Server struct {
 	configurationSupported        bool
 	dynamicConfigurationSupported bool
 	preferredContentFormat        protocol.MarkupKind
+	disabledAnalyses              map[string]struct{}
 
 	textDocumentSyncKind protocol.TextDocumentSyncKind
 

internal/lsp/source/diagnostics.go

@@ -51,7 +51,7 @@ const (
 	SeverityError
 )
 
-func Diagnostics(ctx context.Context, v View, f GoFile) (map[span.URI][]Diagnostic, error) {
+func Diagnostics(ctx context.Context, v View, f GoFile, disabledAnalyses map[string]struct{}) (map[span.URI][]Diagnostic, error) {
 	pkg := f.GetPackage(ctx)
 	if pkg == nil {
 		return singleDiagnostic(f.URI(), "%s is not part of a package", f.URI()), nil
@@ -70,7 +70,7 @@ func Diagnostics(ctx context.Context, v View, f GoFile) (map[span.URI][]Diagnost
 	// Run diagnostics for the package that this URI belongs to.
 	if !diagnostics(ctx, v, pkg, reports) {
 		// If we don't have any list, parse, or type errors, run analyses.
-		if err := analyses(ctx, v, pkg, reports); err != nil {
+		if err := analyses(ctx, v, pkg, disabledAnalyses, reports); err != nil {
 			v.Session().Logger().Errorf(ctx, "failed to run analyses for %s: %v", f.URI(), err)
 		}
 	}
@@ -126,9 +126,9 @@ func diagnostics(ctx context.Context, v View, pkg Package, reports map[span.URI]
 	return len(diags) != 0
 }
 
-func analyses(ctx context.Context, v View, pkg Package, reports map[span.URI][]Diagnostic) error {
+func analyses(ctx context.Context, v View, pkg Package, disabledAnalyses map[string]struct{}, reports map[span.URI][]Diagnostic) error {
 	// Type checking and parsing succeeded. Run analyses.
-	if err := runAnalyses(ctx, v, pkg, func(a *analysis.Analyzer, diag analysis.Diagnostic) error {
+	if err := runAnalyses(ctx, v, pkg, disabledAnalyses, func(a *analysis.Analyzer, diag analysis.Diagnostic) error {
 		r := span.NewRange(v.Session().Cache().FileSet(), diag.Pos, diag.End)
 		s, err := r.Span()
 		if err != nil {
@@ -234,9 +234,10 @@ func singleDiagnostic(uri span.URI, format string, a ...interface{}) map[span.UR
 	}
 }
 
-func runAnalyses(ctx context.Context, v View, pkg Package, report func(a *analysis.Analyzer, diag analysis.Diagnostic) error) error {
+func runAnalyses(ctx context.Context, v View, pkg Package, disabledAnalyses map[string]struct{}, report func(a *analysis.Analyzer, diag analysis.Diagnostic) error) error {
 	// The traditional vet suite:
-	analyzers := []*analysis.Analyzer{
+	var analyzers []*analysis.Analyzer
+	for _, a := range []*analysis.Analyzer{
 		asmdecl.Analyzer,
 		assign.Analyzer,
 		atomic.Analyzer,
@@ -259,6 +260,11 @@ func runAnalyses(ctx context.Context, v View, pkg Package, report func(a *analys
 		unreachable.Analyzer,
 		unsafeptr.Analyzer,
 		unusedresult.Analyzer,
+	} {
+		if _, ok := disabledAnalyses[a.Name]; ok {
+			continue
+		}
+		analyzers = append(analyzers, a)
 	}
 
 	roots, err := analyze(ctx, v, []Package{pkg}, analyzers)

internal/lsp/source/source_test.go

@@ -55,7 +55,7 @@ func (r *runner) Diagnostics(t *testing.T, data tests.Diagnostics) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		results, err := source.Diagnostics(context.Background(), r.view, f.(source.GoFile))
+		results, err := source.Diagnostics(context.Background(), r.view, f.(source.GoFile), nil)
 		if err != nil {
 			t.Fatal(err)
 		}