Golang Config.AfterTypeCheck方法代碼示例

// globalReferrers reports references throughout the entire workspace to the
// object at the specified source position.  Its defining package is defpkg,
// and the query package is qpkg.  isPkgLevel indicates whether the object
// is defined at package-level.
func globalReferrers(q *Query, qpkg, defpkg string, objposn token.Position, isPkgLevel bool) error {
	// Scan the workspace and build the import graph.
	// Ignore broken packages.
	_, rev, _ := importgraph.Build(q.Build)

	// Find the set of packages that depend on defpkg.
	// Only function bodies in those packages need type-checking.
	var users map[string]bool
	if isPkgLevel {
		users = rev[defpkg] // direct importers
		if users == nil {
			users = make(map[string]bool)
		}
		users[defpkg] = true // plus the defining package itself
	} else {
		users = rev.Search(defpkg) // transitive importers
	}

	// Prepare to 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)
	}

	// The remainder of this function is somewhat tricky because it
	// operates on the concurrent stream of packages observed by the
	// loader's AfterTypeCheck hook.  Most of guru's helper
	// functions assume the entire program has already been loaded,
	// so we can't use them here.
	// TODO(adonovan): smooth things out once the other changes have landed.

	// Results are reported concurrently from within the
	// AfterTypeCheck hook.  The program may provide a useful stream
	// of information even if the user doesn't let the program run
	// to completion.

	var (
		mu    sync.Mutex
		qobj  types.Object
		qinfo *loader.PackageInfo // info for qpkg
	)

	// 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.

		// Only inspect packages that depend on the declaring package
		// (and thus were type-checked).
		if lconf.TypeCheckFuncBodies(info.Pkg.Path()) {
			// Record the query object and its package when we see it.
			mu.Lock()
			if qobj == nil && info.Pkg.Path() == defpkg {
				// Find the object by its position (slightly ugly).
				qobj = findObject(fset, &info.Info, objposn)
				if qobj == nil {
					// It really ought to be there;
					// we found it once already.
					log.Fatalf("object at %s not found in package %s",
						objposn, defpkg)
				}

				// Object found.
				qinfo = info
				q.Output(fset, &referrersInitialResult{
					qinfo: qinfo,
					obj:   qobj,
				})
			}
			obj := qobj
			mu.Unlock()

			// Look for references to the query object.
			if obj != nil {
				outputUses(q, fset, usesOf(obj, info), info.Pkg)
			}
		}

		clearInfoFields(info) // save memory
	}

	lconf.Load() // ignore error

//.........這裏部分代碼省略.........

// 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
}