Ejemplo n.º 1
0
// packageReferrers reports all references to the specified package
// throughout the workspace.
func packageReferrers(q *Query, path string) error {
	// Scan the workspace and build the import graph.
	// Ignore broken packages.
	_, rev, _ := importgraph.Build(q.Build)

	// Find the set of packages that directly import the query package.
	// Only those packages need typechecking of function bodies.
	users := rev[path]

	// Load the larger program.
	fset := token.NewFileSet()
	lconf := loader.Config{
		Fset:  fset,
		Build: q.Build,
		TypeCheckFuncBodies: func(p string) bool {
			return users[strings.TrimSuffix(p, "_test")]
		},
	}
	allowErrors(&lconf)

	// The importgraph doesn't treat external test packages
	// as separate nodes, so we must use ImportWithTests.
	for path := range users {
		lconf.ImportWithTests(path)
	}

	// Subtle!  AfterTypeCheck needs no mutex for qpkg because the
	// topological import order gives us the necessary happens-before edges.
	// TODO(adonovan): what about import cycles?
	var qpkg *types.Package

	// For efficiency, we scan each package for references
	// just after it has been type-checked.  The loader calls
	// AfterTypeCheck (concurrently), providing us with a stream of
	// packages.
	lconf.AfterTypeCheck = func(info *loader.PackageInfo, files []*ast.File) {
		// AfterTypeCheck may be called twice for the same package due to augmentation.

		if info.Pkg.Path() == path && qpkg == nil {
			// Found the package of interest.
			qpkg = info.Pkg
			fakepkgname := types.NewPkgName(token.NoPos, qpkg, qpkg.Name(), qpkg)
			q.Output(fset, &referrersInitialResult{
				qinfo: info,
				obj:   fakepkgname, // bogus
			})
		}

		// Only inspect packages that directly import the
		// declaring package (and thus were type-checked).
		if lconf.TypeCheckFuncBodies(info.Pkg.Path()) {
			// Find PkgNames that refer to qpkg.
			// TODO(adonovan): perhaps more useful would be to show imports
			// of the package instead of qualified identifiers.
			var refs []*ast.Ident
			for id, obj := range info.Uses {
				if obj, ok := obj.(*types.PkgName); ok && obj.Imported() == qpkg {
					refs = append(refs, id)
				}
			}
			outputUses(q, fset, refs, info.Pkg)
		}

		clearInfoFields(info) // save memory
	}

	lconf.Load() // ignore error

	if qpkg == nil {
		log.Fatalf("query package %q not found during reloading", path)
	}

	return nil
}
Ejemplo n.º 2
0
// Referrers reports all identifiers that resolve to the same object
// as the queried identifier, within any package in the analysis scope.
func referrers(q *Query) error {
	lconf := loader.Config{Build: q.Build}
	allowErrors(&lconf)

	if _, err := importQueryPackage(q.Pos, &lconf); err != nil {
		return err
	}

	var id *ast.Ident
	var obj types.Object
	var lprog *loader.Program
	var pass2 bool
	var qpos *queryPos
	for {
		// Load/parse/type-check the program.
		var err error
		lprog, err = lconf.Load()
		if err != nil {
			return err
		}
		q.Fset = lprog.Fset

		qpos, err = parseQueryPos(lprog, q.Pos, false)
		if err != nil {
			return err
		}

		id, _ = qpos.path[0].(*ast.Ident)
		if id == nil {
			return fmt.Errorf("no identifier here")
		}

		obj = qpos.info.ObjectOf(id)
		if obj == nil {
			// Happens for y in "switch y := x.(type)",
			// the package declaration,
			// and unresolved identifiers.
			if _, ok := qpos.path[1].(*ast.File); ok { // package decl?
				pkg := qpos.info.Pkg
				obj = types.NewPkgName(id.Pos(), pkg, pkg.Name(), pkg)
			} else {
				return fmt.Errorf("no object for identifier: %T", qpos.path[1])
			}
		}

		if pass2 {
			break
		}

		// If the identifier is exported, we must load all packages that
		// depend transitively upon the package that defines it.
		// Treat PkgNames as exported, even though they're lowercase.
		if _, isPkg := obj.(*types.PkgName); !(isPkg || obj.Exported()) {
			break // not exported
		}

		// Scan the workspace and build the import graph.
		// Ignore broken packages.
		_, rev, _ := importgraph.Build(q.Build)

		// Re-load the larger program.
		// Create a new file set so that ...
		// External test packages are never imported,
		// so they will never appear in the graph.
		// (We must reset the Config here, not just reset the Fset field.)
		lconf = loader.Config{
			Fset:  token.NewFileSet(),
			Build: q.Build,
		}
		allowErrors(&lconf)
		for path := range rev.Search(obj.Pkg().Path()) {
			lconf.ImportWithTests(path)
		}
		pass2 = true
	}

	// Iterate over all go/types' Uses facts for the entire program.
	var refs []*ast.Ident
	for _, info := range lprog.AllPackages {
		for id2, obj2 := range info.Uses {
			if sameObj(obj, obj2) {
				refs = append(refs, id2)
			}
		}
	}
	sort.Sort(byNamePos{q.Fset, refs})

	q.result = &referrersResult{
		qpos:  qpos,
		query: id,
		obj:   obj,
		refs:  refs,
	}
	return nil
}