diff options
Diffstat (limited to 'src/pkg/go/ast/resolve.go')
| -rw-r--r-- | src/pkg/go/ast/resolve.go | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/src/pkg/go/ast/resolve.go b/src/pkg/go/ast/resolve.go deleted file mode 100644 index 0406bfc58..000000000 --- a/src/pkg/go/ast/resolve.go +++ /dev/null @@ -1,174 +0,0 @@ -// Copyright 2011 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. - -// This file implements NewPackage. - -package ast - -import ( - "fmt" - "go/scanner" - "go/token" - "strconv" -) - -type pkgBuilder struct { - fset *token.FileSet - errors scanner.ErrorList -} - -func (p *pkgBuilder) error(pos token.Pos, msg string) { - p.errors.Add(p.fset.Position(pos), msg) -} - -func (p *pkgBuilder) errorf(pos token.Pos, format string, args ...interface{}) { - p.error(pos, fmt.Sprintf(format, args...)) -} - -func (p *pkgBuilder) declare(scope, altScope *Scope, obj *Object) { - alt := scope.Insert(obj) - if alt == nil && altScope != nil { - // see if there is a conflicting declaration in altScope - alt = altScope.Lookup(obj.Name) - } - if alt != nil { - prevDecl := "" - if pos := alt.Pos(); pos.IsValid() { - prevDecl = fmt.Sprintf("\n\tprevious declaration at %s", p.fset.Position(pos)) - } - p.error(obj.Pos(), fmt.Sprintf("%s redeclared in this block%s", obj.Name, prevDecl)) - } -} - -func resolve(scope *Scope, ident *Ident) bool { - for ; scope != nil; scope = scope.Outer { - if obj := scope.Lookup(ident.Name); obj != nil { - ident.Obj = obj - return true - } - } - return false -} - -// 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 error) - -// NewPackage creates a new Package node from a set of File nodes. It resolves -// unresolved identifiers across files and updates each file's Unresolved list -// accordingly. If a non-nil importer and universe scope are provided, they are -// 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 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, error) { - var p pkgBuilder - p.fset = fset - - // complete package scope - pkgName := "" - pkgScope := NewScope(universe) - for _, file := range files { - // package names must match - switch name := file.Name.Name; { - case pkgName == "": - pkgName = name - case name != pkgName: - p.errorf(file.Package, "package %s; expected %s", name, pkgName) - continue // ignore this file - } - - // collect top-level file objects in package scope - for _, obj := range file.Scope.Objects { - p.declare(pkgScope, nil, obj) - } - } - - // 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 { - // ignore file if it belongs to a different package - // (error has already been reported) - if file.Name.Name != pkgName { - continue - } - - // build file scope by processing all imports - importErrors := false - fileScope := NewScope(pkgScope) - for _, spec := range file.Imports { - if importer == nil { - importErrors = true - continue - } - path, _ := strconv.Unquote(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 - 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.Data.(*Scope).Objects { - p.declare(fileScope, pkgScope, obj) - } - } else if name != "_" { - // 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) - } - } - - // resolve identifiers - 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 - // incorrectly to universe objects) - pkgScope.Outer = nil - } - i := 0 - for _, ident := range file.Unresolved { - if !resolve(fileScope, ident) { - p.errorf(ident.Pos(), "undeclared name: %s", ident.Name) - file.Unresolved[i] = ident - i++ - } - - } - file.Unresolved = file.Unresolved[0:i] - pkgScope.Outer = universe // reset universe scope - } - - p.errors.Sort() - return &Package{pkgName, pkgScope, imports, files}, p.errors.Err() -} |