diff options
Diffstat (limited to 'src/pkg/go/ast/resolve.go')
| -rw-r--r-- | src/pkg/go/ast/resolve.go | 83 |
1 files changed, 38 insertions, 45 deletions
diff --git a/src/pkg/go/ast/resolve.go b/src/pkg/go/ast/resolve.go index fddc3baab..ecd2e8a7c 100644 --- a/src/pkg/go/ast/resolve.go +++ b/src/pkg/go/ast/resolve.go @@ -11,6 +11,7 @@ import ( "go/scanner" "go/token" "os" + "strconv" ) @@ -57,11 +58,16 @@ func resolve(scope *Scope, ident *Ident) bool { } -// NewPackage uses an Importer to resolve imports. Given an importPath, -// an importer returns the imported package's name, its scope of exported -// objects, and an error, if any. -// -type Importer func(path string) (name string, scope *Scope, err os.Error) +// An Importer resolves import paths to package Objects. +// The imports map records the packages already imported, +// indexed by package id (canonical import path). +// An Importer must determine the canonical import path and +// check the map to see if it is already present in the imports map. +// If so, the Importer can return the map entry. Otherwise, the +// Importer should load the package data for the given path into +// a new *Object (pkg), record pkg in the imports map, and then +// return pkg. +type Importer func(imports map[string]*Object, path string) (pkg *Object, err os.Error) // NewPackage creates a new Package node from a set of File nodes. It resolves @@ -70,7 +76,7 @@ type Importer func(path string) (name string, scope *Scope, err os.Error) // used to resolve identifiers not declared in any of the package files. Any // remaining unresolved identifiers are reported as undeclared. If the files // belong to different packages, one package name is selected and files with -// different package name are reported and then ignored. +// different package names are reported and then ignored. // The result is a package node and a scanner.ErrorList if there were errors. // func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, universe *Scope) (*Package, os.Error) { @@ -96,14 +102,8 @@ func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, } } - // imports maps import paths to package names and scopes - // TODO(gri): Eventually we like to get to the import scope from - // a package object. Then we can have a map path -> Obj. - type importedPkg struct { - name string - scope *Scope - } - imports := make(map[string]*importedPkg) + // package global mapping of imported package ids to package objects + imports := make(map[string]*Object) // complete file scopes with imports and resolve identifiers for _, file := range files { @@ -117,42 +117,41 @@ func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, importErrors := false fileScope := NewScope(pkgScope) for _, spec := range file.Imports { - // add import to global map of imports - path := string(spec.Path.Value) - path = path[1 : len(path)-1] // strip ""'s - pkg := imports[path] - if pkg == nil { - if importer == nil { - importErrors = true - continue - } - name, scope, err := importer(path) - if err != nil { - p.errorf(spec.Path.Pos(), "could not import %s (%s)", path, err) - importErrors = true - continue - } - pkg = &importedPkg{name, scope} - imports[path] = pkg - // TODO(gri) If a local package name != "." is provided, - // global identifier resolution could proceed even if the - // import failed. Consider adjusting the logic here a bit. + if importer == nil { + importErrors = true + continue + } + path, _ := strconv.Unquote(string(spec.Path.Value)) + pkg, err := importer(imports, path) + if err != nil { + p.errorf(spec.Path.Pos(), "could not import %s (%s)", path, err) + importErrors = true + continue } + // TODO(gri) If a local package name != "." is provided, + // global identifier resolution could proceed even if the + // import failed. Consider adjusting the logic here a bit. + // local name overrides imported package name - name := pkg.name + name := pkg.Name if spec.Name != nil { name = spec.Name.Name } + // add import to file scope if name == "." { // merge imported scope with file scope - for _, obj := range pkg.scope.Objects { + for _, obj := range pkg.Data.(*Scope).Objects { p.declare(fileScope, pkgScope, obj) } } else { // declare imported package object in file scope + // (do not re-use pkg in the file scope but create + // a new object instead; the Decl field is different + // for different files) obj := NewObj(Pkg, name) obj.Decl = spec + obj.Data = pkg.Data p.declare(fileScope, pkgScope, obj) } } @@ -161,8 +160,8 @@ func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, if importErrors { // don't use the universe scope without correct imports // (objects in the universe may be shadowed by imports; - // with missing imports identifiers might get resolved - // wrongly) + // with missing imports, identifiers might get resolved + // incorrectly to universe objects) pkgScope.Outer = nil } i := 0 @@ -178,11 +177,5 @@ func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, pkgScope.Outer = universe // reset universe scope } - // collect all import paths and respective package scopes - importedScopes := make(map[string]*Scope) - for path, pkg := range imports { - importedScopes[path] = pkg.scope - } - - return &Package{pkgName, pkgScope, importedScopes, files}, p.GetError(scanner.Sorted) + return &Package{pkgName, pkgScope, imports, files}, p.GetError(scanner.Sorted) } |