internal/lsp: use correct file identities when computing diagnostics

CL 214586 switched to using URIs in error messages instead of file
identities. It wasn't fully correct because the reports were being
allocated for the file identities in the package handle (which may be
outdated).

Fixes golang/go#36601

Change-Id: I4fcfc02df74d94fff49540c784ef816c357e7232
Reviewed-on: https://go-review.googlesource.com/c/tools/+/215680
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

Author: stamblerre

internal/lsp/source/diagnostics.go

@@ -6,7 +6,6 @@ package source
 
 import (
 	"context"
-	"fmt"
 	"strings"
 
 	"golang.org/x/tools/go/analysis"
@@ -69,7 +68,9 @@ func Diagnostics(ctx context.Context, snapshot Snapshot, ph PackageHandle, withA
 	// Prepare the reports we will send for the files in this package.
 	reports := make(map[FileIdentity][]Diagnostic)
 	for _, fh := range pkg.CompiledGoFiles() {
-		clearReports(snapshot, reports, fh.File().Identity())
+		if err := clearReports(snapshot, reports, fh.File().Identity().URI); err != nil {
+			return nil, warningMsg, err
+		}
 	}
 	// Prepare any additional reports for the errors in this package.
 	for _, e := range pkg.GetErrors() {
@@ -85,11 +86,9 @@ func Diagnostics(ctx context.Context, snapshot Snapshot, ph PackageHandle, withA
 				}
 			}
 		}
-		fh, err := snapshot.GetFile(e.URI)
-		if err != nil {
+		if err := clearReports(snapshot, reports, e.URI); err != nil {
 			return nil, warningMsg, err
 		}
-		clearReports(snapshot, reports, fh.Identity())
 	}
 	// Run diagnostics for the package that this URI belongs to.
 	hadDiagnostics, err := diagnostics(ctx, snapshot, reports, pkg)
@@ -142,21 +141,17 @@ func diagnostics(ctx context.Context, snapshot Snapshot, reports map[FileIdentit
 	_ = ctx // circumvent SA4006
 	defer done()
 
-	diagSets := make(map[FileIdentity]*diagnosticSet)
+	diagSets := make(map[span.URI]*diagnosticSet)
 	for _, e := range pkg.GetErrors() {
 		diag := &Diagnostic{
 			Message:  e.Message,
 			Range:    e.Range,
 			Severity: protocol.SeverityError,
 		}
-		fh, err := snapshot.GetFile(e.URI)
-		if err != nil {
-			return false, err
-		}
-		set, ok := diagSets[fh.Identity()]
+		set, ok := diagSets[e.URI]
 		if !ok {
 			set = &diagnosticSet{}
-			diagSets[fh.Identity()] = set
+			diagSets[e.URI] = set
 		}
 		switch e.Kind {
 		case ParseError:
@@ -171,7 +166,7 @@ func diagnostics(ctx context.Context, snapshot Snapshot, reports map[FileIdentit
 		}
 	}
 	var nonEmptyDiagnostics bool // track if we actually send non-empty diagnostics
-	for fileID, set := range diagSets {
+	for uri, set := range diagSets {
 		// Don't report type errors if there are parse errors or list errors.
 		diags := set.typeErrors
 		if len(set.parseErrors) > 0 {
@@ -182,7 +177,9 @@ func diagnostics(ctx context.Context, snapshot Snapshot, reports map[FileIdentit
 		if len(diags) > 0 {
 			nonEmptyDiagnostics = true
 		}
-		addReports(ctx, snapshot, reports, fileID, diags...)
+		if err := addReports(ctx, snapshot, reports, uri, diags...); err != nil {
+			return false, err
+		}
 	}
 	return nonEmptyDiagnostics, nil
 }
@@ -210,59 +207,53 @@ func analyses(ctx context.Context, snapshot Snapshot, reports map[FileIdentity][
 		if onlyDeletions(e.SuggestedFixes) {
 			tags = append(tags, protocol.Unnecessary)
 		}
-		fh, err := snapshot.GetFile(e.URI)
-		if err != nil {
-			return err
-		}
-		addReports(ctx, snapshot, reports, fh.Identity(), &Diagnostic{
+		if err := addReports(ctx, snapshot, reports, e.URI, &Diagnostic{
 			Range:          e.Range,
 			Message:        e.Message,
 			Source:         e.Category,
 			Severity:       protocol.SeverityWarning,
 			Tags:           tags,
 			SuggestedFixes: e.SuggestedFixes,
 			Related:        e.Related,
-		})
+		}); err != nil {
+			return err
+		}
 	}
 	return nil
 }
 
-func clearReports(snapshot Snapshot, reports map[FileIdentity][]Diagnostic, fileID FileIdentity) {
-	if snapshot.View().Ignore(fileID.URI) {
-		return
+func clearReports(snapshot Snapshot, reports map[FileIdentity][]Diagnostic, uri span.URI) error {
+	if snapshot.View().Ignore(uri) {
+		return nil
 	}
-	reports[fileID] = []Diagnostic{}
+	fh, err := snapshot.GetFile(uri)
+	if err != nil {
+		return err
+	}
+	reports[fh.Identity()] = []Diagnostic{}
+	return nil
 }
 
-func addReports(ctx context.Context, snapshot Snapshot, reports map[FileIdentity][]Diagnostic, fileID FileIdentity, diagnostics ...*Diagnostic) error {
-	if snapshot.View().Ignore(fileID.URI) {
+func addReports(ctx context.Context, snapshot Snapshot, reports map[FileIdentity][]Diagnostic, uri span.URI, diagnostics ...*Diagnostic) error {
+	if snapshot.View().Ignore(uri) {
 		return nil
 	}
-	if _, ok := reports[fileID]; !ok {
-		return errors.Errorf("diagnostics for unexpected file %s", fileID.URI)
+	fh, err := snapshot.GetFile(uri)
+	if err != nil {
+		return err
+	}
+	if _, ok := reports[fh.Identity()]; !ok {
+		return errors.Errorf("diagnostics for unexpected file %s", uri)
 	}
 	for _, diag := range diagnostics {
 		if diag == nil {
 			continue
 		}
-		reports[fileID] = append(reports[fileID], *diag)
+		reports[fh.Identity()] = append(reports[fh.Identity()], *diag)
 	}
 	return nil
 }
 
-func singleDiagnostic(fileID FileIdentity, format string, a ...interface{}) map[FileIdentity][]Diagnostic {
-	return map[FileIdentity][]Diagnostic{
-		fileID: []Diagnostic{
-			{
-				Source:   "gopls",
-				Range:    protocol.Range{},
-				Message:  fmt.Sprintf(format, a...),
-				Severity: protocol.SeverityError,
-			},
-		},
-	}
-}
-
 // onlyDeletions returns true if all of the suggested fixes are deletions.
 func onlyDeletions(fixes []SuggestedFix) bool {
 	for _, fix := range fixes {