gopls: add CompiledAsmFiles in cache.Package

gopls/internal/cache/check.go

@@ -1456,12 +1456,12 @@ type typeCheckInputs struct {
 	id PackageID
 
 	// Used for type checking:
-	pkgPath                  PackagePath
-	name                     PackageName
-	goFiles, compiledGoFiles []file.Handle
-	sizes                    types.Sizes
-	depsByImpPath            map[ImportPath]PackageID
-	goVersion                string // packages.Module.GoVersion, e.g. "1.18"
+	pkgPath                            PackagePath
+	name                               PackageName
+	goFiles, compiledGoFiles, asmFiles []file.Handle
+	sizes                              types.Sizes
+	depsByImpPath                      map[ImportPath]PackageID
+	goVersion                          string // packages.Module.GoVersion, e.g. "1.18"
 
 	// Used for type check diagnostics:
 	// TODO(rfindley): consider storing less data in gobDiagnostics, and
@@ -1491,6 +1491,10 @@ func (s *Snapshot) typeCheckInputs(ctx context.Context, mp *metadata.Package) (*
 	if err != nil {
 		return nil, err
 	}
+	asmFiles, err := readFiles(ctx, s, mp.AsmFiles)
+	if err != nil {
+		return nil, err
+	}
 
 	goVersion := ""
 	if mp.Module != nil && mp.Module.GoVersion != "" {
@@ -1503,6 +1507,7 @@ func (s *Snapshot) typeCheckInputs(ctx context.Context, mp *metadata.Package) (*
 		name:            mp.Name,
 		goFiles:         goFiles,
 		compiledGoFiles: compiledGoFiles,
+		asmFiles:        asmFiles,
 		sizes:           mp.TypesSizes,
 		depsByImpPath:   mp.DepsByImpPath,
 		goVersion:       goVersion,
@@ -1555,6 +1560,10 @@ func localPackageKey(inputs *typeCheckInputs) file.Hash {
 	for _, fh := range inputs.goFiles {
 		fmt.Fprintln(hasher, fh.Identity())
 	}
+	fmt.Fprintf(hasher, "asmFiles:%d\n", len(inputs.asmFiles))
+	for _, fh := range inputs.asmFiles {
+		fmt.Fprintln(hasher, fh.Identity())
+	}
 
 	// types sizes
 	wordSize := inputs.sizes.Sizeof(types.Typ[types.Int])
@@ -1611,6 +1620,10 @@ func (b *typeCheckBatch) checkPackage(ctx context.Context, fset *token.FileSet,
 			pkg.parseErrors = append(pkg.parseErrors, pgf.ParseErr)
 		}
 	}
+	pkg.asmFiles, err = parseAsmFiles(ctx, inputs.asmFiles...)
+	if err != nil {
+		return nil, err
+	}
 
 	// Use the default type information for the unsafe package.
 	if inputs.pkgPath == "unsafe" {

gopls/internal/cache/load.go

@@ -454,6 +454,13 @@ func buildMetadata(updates map[PackageID]*metadata.Package, loadDir string, stan
 			*dst = append(*dst, protocol.URIFromPath(filename))
 		}
 	}
+	// Copy SFiles to AsmFiles.
+	for _, filename := range pkg.OtherFiles {
+		if !strings.HasSuffix(filename, ".s") {
+			continue
+		}
+		mp.AsmFiles = append(mp.AsmFiles, protocol.URIFromPath(filename))
+	}
 	copyURIs(&mp.CompiledGoFiles, pkg.CompiledGoFiles)
 	copyURIs(&mp.GoFiles, pkg.GoFiles)
 	copyURIs(&mp.IgnoredFiles, pkg.IgnoredFiles)

gopls/internal/cache/metadata/metadata.go

@@ -51,6 +51,8 @@ type Package struct {
 	IgnoredFiles    []protocol.DocumentURI
 	OtherFiles      []protocol.DocumentURI
 
+	AsmFiles []protocol.DocumentURI // *.s subset of OtherFiles
+
 	ForTest       PackagePath // q in a "p [q.test]" package, else ""
 	TypesSizes    types.Sizes
 	Errors        []packages.Error          // must be set for packages in import cycles

gopls/internal/cache/package.go

@@ -19,6 +19,7 @@ import (
 	"golang.org/x/tools/gopls/internal/cache/testfuncs"
 	"golang.org/x/tools/gopls/internal/cache/xrefs"
 	"golang.org/x/tools/gopls/internal/protocol"
+	"golang.org/x/tools/gopls/internal/util/asm"
 )
 
 // Convenient aliases for very heavily used types.
@@ -49,6 +50,7 @@ type syntaxPackage struct {
 	fset            *token.FileSet // for now, same as the snapshot's FileSet
 	goFiles         []*parsego.File
 	compiledGoFiles []*parsego.File
+	asmFiles        []*asm.File
 	diagnostics     []*Diagnostic
 	parseErrors     []scanner.ErrorList
 	typeErrors      []types.Error
@@ -69,7 +71,7 @@ type syntaxPackage struct {
 
 func (p *syntaxPackage) xrefs() []byte {
 	p.xrefsOnce.Do(func() {
-		p._xrefs = xrefs.Index(p.compiledGoFiles, p.types, p.typesInfo)
+		p._xrefs = xrefs.Index(p.compiledGoFiles, p.types, p.typesInfo, p.asmFiles)
 	})
 	return p._xrefs
 }
@@ -200,3 +202,21 @@ func (p *Package) ParseErrors() []scanner.ErrorList {
 func (p *Package) TypeErrors() []types.Error {
 	return p.pkg.typeErrors
 }
+
+func (p *Package) AsmFiles() []*asm.File {
+	return p.pkg.asmFiles
+}
+
+func (p *Package) AsmFile(uri protocol.DocumentURI) (*asm.File, error) {
+	return p.pkg.AsmFile(uri)
+}
+
+func (pkg *syntaxPackage) AsmFile(uri protocol.DocumentURI) (*asm.File, error) {
+	for _, af := range pkg.asmFiles {
+		if af.URI == uri {
+			return af, nil
+		}
+	}
+
+	return nil, fmt.Errorf("no parsed file for %s in %v", uri, pkg.id)
+}

gopls/internal/cache/parse.go

@@ -13,6 +13,7 @@ import (
 
 	"golang.org/x/tools/gopls/internal/cache/parsego"
 	"golang.org/x/tools/gopls/internal/file"
+	"golang.org/x/tools/gopls/internal/util/asm"
 )
 
 // ParseGo parses the file whose contents are provided by fh.
@@ -43,3 +44,21 @@ func parseGoImpl(ctx context.Context, fset *token.FileSet, fh file.Handle, mode
 	pgf, _ := parsego.Parse(ctx, fset, fh.URI(), content, mode, purgeFuncBodies) // ignore 'fixes'
 	return pgf, nil
 }
+
+// parseAsmFiles parses the assembly files whose contents are provided by fhs.
+func parseAsmFiles(ctx context.Context, fhs ...file.Handle) ([]*asm.File, error) {
+	pafs := make([]*asm.File, len(fhs))
+	for i, fh := range fhs {
+		var err error
+		content, err := fh.Content()
+		if err != nil {
+			return nil, err
+		}
+		// Check for context cancellation before actually doing the parse.
+		if ctx.Err() != nil {
+			return nil, ctx.Err()
+		}
+		pafs[i] = asm.Parse(fh.URI(), content)
+	}
+	return pafs, nil
+}

gopls/internal/cache/xrefs/xrefs.go

@@ -11,19 +11,22 @@ package xrefs
 import (
 	"go/ast"
 	"go/types"
+	"slices"
 	"sort"
 
 	"golang.org/x/tools/go/types/objectpath"
 	"golang.org/x/tools/gopls/internal/cache/metadata"
 	"golang.org/x/tools/gopls/internal/cache/parsego"
 	"golang.org/x/tools/gopls/internal/protocol"
+	"golang.org/x/tools/gopls/internal/util/asm"
 	"golang.org/x/tools/gopls/internal/util/bug"
 	"golang.org/x/tools/gopls/internal/util/frob"
+	"golang.org/x/tools/gopls/internal/util/morestrings"
 )
 
 // Index constructs a serializable index of outbound cross-references
 // for the specified type-checked package.
-func Index(files []*parsego.File, pkg *types.Package, info *types.Info) []byte {
+func Index(files []*parsego.File, pkg *types.Package, info *types.Info, asmFiles []*asm.File) []byte {
 	// pkgObjects maps each referenced package Q to a mapping:
 	// from each referenced symbol in Q to the ordered list
 	// of references to that symbol from this package.
@@ -112,6 +115,34 @@ func Index(files []*parsego.File, pkg *types.Package, info *types.Info) []byte {
 		}
 	}
 
+	// For each asm file, record references to identifiers.
+	for fileIndex, af := range asmFiles {
+		for _, id := range af.Idents {
+			_, name, ok := morestrings.CutLast(id.Name, ".")
+			if !ok {
+				continue
+			}
+			obj := pkg.Scope().Lookup(name)
+			if obj == nil {
+				// TODO(grootguo): If the object is not found in the current package,
+				// consider handling cross-package references.
+				continue
+			}
+			objects := getObjects(pkg)
+			gobObj, ok := objects[obj]
+			if !ok {
+				gobObj = &gobObject{Path: objectpath.Path(obj.Name())}
+				objects[obj] = gobObj
+			}
+			if rng, err := af.NodeRange(id); err == nil {
+				gobObj.Refs = append(gobObj.Refs, gobRef{
+					FileIndex: fileIndex,
+					Range:     rng,
+				})
+			}
+		}
+	}
+
 	// Flatten the maps into slices, and sort for determinism.
 	var packages []*gobPackage
 	for p := range pkgObjects {
@@ -147,7 +178,7 @@ func Lookup(mp *metadata.Package, data []byte, targets map[metadata.PackagePath]
 			for _, gobObj := range gp.Objects {
 				if _, ok := objectSet[gobObj.Path]; ok {
 					for _, ref := range gobObj.Refs {
-						uri := mp.CompiledGoFiles[ref.FileIndex]
+						uri := slices.Concat(mp.CompiledGoFiles, mp.AsmFiles)[ref.FileIndex]
 						locs = append(locs, protocol.Location{
 							URI:   uri,
 							Range: ref.Range,

gopls/internal/goasm/definition.go

@@ -45,7 +45,7 @@ func Definition(ctx context.Context, snapshot *cache.Snapshot, fh file.Handle, p
 	//
 	// TODO(adonovan): make this just another
 	// attribute of the type-checked cache.Package.
-	file := asm.Parse(content)
+	file := asm.Parse(fh.URI(), content)
 
 	// Figure out the selected symbol.
 	// For now, just find the identifier around the cursor.

gopls/internal/goasm/references.go

@@ -0,0 +1,125 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package goasm provides language-server features for files in Go
+// assembly language (https://go.dev/doc/asm).
+package goasm
+
+import (
+	"context"
+	"fmt"
+	"go/ast"
+	"go/types"
+
+	"golang.org/x/tools/gopls/internal/cache"
+	"golang.org/x/tools/gopls/internal/cache/metadata"
+	"golang.org/x/tools/gopls/internal/file"
+	"golang.org/x/tools/gopls/internal/protocol"
+	"golang.org/x/tools/gopls/internal/util/asm"
+	"golang.org/x/tools/gopls/internal/util/morestrings"
+	"golang.org/x/tools/internal/event"
+)
+
+// References returns a list of locations (file and position) where the symbol under the cursor in an assembly file is referenced,
+// including both Go source files and assembly files within the same package.
+func References(ctx context.Context, snapshot *cache.Snapshot, fh file.Handle, position protocol.Position, includeDeclaration bool) ([]protocol.Location, error) {
+	ctx, done := event.Start(ctx, "goasm.References")
+	defer done()
+
+	mps, err := snapshot.MetadataForFile(ctx, fh.URI())
+	if err != nil {
+		return nil, err
+	}
+	metadata.RemoveIntermediateTestVariants(&mps)
+	if len(mps) == 0 {
+		return nil, fmt.Errorf("no package metadata for file %s", fh.URI())
+	}
+	mp := mps[0]
+	pkgs, err := snapshot.TypeCheck(ctx, mp.ID)
+	if err != nil {
+		return nil, err
+	}
+	pkg := pkgs[0]
+	asmFile, err := pkg.AsmFile(fh.URI())
+	if err != nil {
+		return nil, err // "can't happen"
+	}
+
+	offset, err := asmFile.Mapper.PositionOffset(position)
+	if err != nil {
+		return nil, err
+	}
+
+	// Figure out the selected symbol.
+	// For now, just find the identifier around the cursor.
+	var found *asm.Ident
+	for _, id := range asmFile.Idents {
+		if id.Offset <= offset && offset <= id.End() {
+			found = &id
+			break
+		}
+	}
+	if found == nil {
+		return nil, fmt.Errorf("not an identifier")
+	}
+
+	sym := found.Name
+	var locations []protocol.Location
+	_, name, ok := morestrings.CutLast(sym, ".")
+	if !ok {
+		return nil, fmt.Errorf("not found")
+	}
+
+	// TODO(grootguo): Currently, only references to the symbol within the package are found (i.e., only Idents in this package's Go files are searched).
+	// It is still necessary to implement cross-package reference lookup: that is, to find all references to this symbol in other packages that import the current package.
+	// Refer to the global search logic in golang.References, and add corresponding test cases for verification.
+	obj := pkg.Types().Scope().Lookup(name)
+	matches := func(curObj types.Object) bool {
+		if curObj == nil {
+			return false
+		}
+		if curObj.Name() != obj.Name() {
+			return false
+		}
+		return true
+	}
+	for _, pgf := range pkg.CompiledGoFiles() {
+		for curId := range pgf.Cursor.Preorder((*ast.Ident)(nil)) {
+			id := curId.Node().(*ast.Ident)
+			curObj, ok := pkg.TypesInfo().Defs[id]
+			if !ok {
+				curObj, ok = pkg.TypesInfo().Uses[id]
+				if !ok {
+					continue
+				}
+			}
+			if !matches(curObj) {
+				continue
+			}
+			loc, err := pgf.NodeLocation(id)
+			if err != nil {
+				return nil, err
+			}
+			locations = append(locations, loc)
+		}
+	}
+
+	// If includeDeclaration is false, return only reference locations (exclude declarations).
+	if !includeDeclaration {
+		return locations, nil
+	}
+
+	for _, asmFile := range pkg.AsmFiles() {
+		for _, id := range asmFile.Idents {
+			if id.Name != sym {
+				continue
+			}
+			if loc, err := asmFile.NodeLocation(id); err == nil {
+				locations = append(locations, loc)
+			}
+		}
+	}
+
+	return locations, nil
+}