return fst
}
+type (
+ decl interface {
+ node() ast.Node
+ }
+
+ importDecl struct{ spec *ast.ImportSpec }
+ constDecl struct {
+ spec *ast.ValueSpec
+ iota int
+ typ ast.Expr
+ init []ast.Expr
+ }
+ varDecl struct{ spec *ast.ValueSpec }
+ typeDecl struct{ spec *ast.TypeSpec }
+ funcDecl struct{ decl *ast.FuncDecl }
+)
+
+func (d importDecl) node() ast.Node { return d.spec }
+func (d constDecl) node() ast.Node { return d.spec }
+func (d varDecl) node() ast.Node { return d.spec }
+func (d typeDecl) node() ast.Node { return d.spec }
+func (d funcDecl) node() ast.Node { return d.decl }
+
+func (check *Checker) walkDecls(decls []ast.Decl, f func(decl)) {
+ for _, d := range decls {
+ check.walkDecl(d, f)
+ }
+}
+
+func (check *Checker) walkDecl(d ast.Decl, f func(decl)) {
+ switch d := d.(type) {
+ case *ast.BadDecl:
+ // ignore
+ case *ast.GenDecl:
+ var last *ast.ValueSpec // last ValueSpec with type or init exprs seen
+ for iota, s := range d.Specs {
+ switch s := s.(type) {
+ case *ast.ImportSpec:
+ f(importDecl{s})
+ case *ast.ValueSpec:
+ switch d.Tok {
+ case token.CONST:
+ // determine which initialization expressions to use
+ switch {
+ case s.Type != nil || len(s.Values) > 0:
+ last = s
+ case last == nil:
+ last = new(ast.ValueSpec) // make sure last exists
+ }
+ check.arityMatch(s, last)
+ f(constDecl{spec: s, iota: iota, init: last.Values, typ: last.Type})
+ case token.VAR:
+ check.arityMatch(s, nil)
+ f(varDecl{s})
+ default:
+ check.invalidAST(s.Pos(), "invalid token %s", d.Tok)
+ }
+ case *ast.TypeSpec:
+ f(typeDecl{s})
+ default:
+ check.invalidAST(s.Pos(), "unknown ast.Spec node %T", s)
+ }
+ }
+ case *ast.FuncDecl:
+ f(funcDecl{d})
+ default:
+ check.invalidAST(d.Pos(), "unknown ast.Decl node %T", d)
+ }
+}
+
func (check *Checker) constDecl(obj *Const, typ, init ast.Expr) {
assert(obj.typ == nil)
}
}
-func (check *Checker) declStmt(decl ast.Decl) {
+func (check *Checker) declStmt(d ast.Decl) {
pkg := check.pkg
- switch d := decl.(type) {
- case *ast.BadDecl:
- // ignore
+ check.walkDecl(d, func(d decl) {
+ switch d := d.(type) {
+ case constDecl:
+ top := len(check.delayed)
- case *ast.GenDecl:
- var last *ast.ValueSpec // last ValueSpec with type or init exprs seen
- for iota, spec := range d.Specs {
- switch s := spec.(type) {
- case *ast.ValueSpec:
- switch d.Tok {
- case token.CONST:
- top := len(check.delayed)
+ // declare all constants
+ lhs := make([]*Const, len(d.spec.Names))
+ for i, name := range d.spec.Names {
+ obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(d.iota)))
+ lhs[i] = obj
- // determine which init exprs to use
- switch {
- case s.Type != nil || len(s.Values) > 0:
- last = s
- case last == nil:
- last = new(ast.ValueSpec) // make sure last exists
- }
-
- // declare all constants
- lhs := make([]*Const, len(s.Names))
- for i, name := range s.Names {
- obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(iota)))
- lhs[i] = obj
-
- var init ast.Expr
- if i < len(last.Values) {
- init = last.Values[i]
- }
+ var init ast.Expr
+ if i < len(d.init) {
+ init = d.init[i]
+ }
- check.constDecl(obj, last.Type, init)
- }
+ check.constDecl(obj, d.typ, init)
+ }
- check.arityMatch(s, last)
+ // process function literals in init expressions before scope changes
+ check.processDelayed(top)
- // process function literals in init expressions before scope changes
- check.processDelayed(top)
+ // spec: "The scope of a constant or variable identifier declared
+ // inside a function begins at the end of the ConstSpec or VarSpec
+ // (ShortVarDecl for short variable declarations) and ends at the
+ // end of the innermost containing block."
+ scopePos := d.spec.End()
+ for i, name := range d.spec.Names {
+ check.declare(check.scope, name, lhs[i], scopePos)
+ }
- // spec: "The scope of a constant or variable identifier declared
- // inside a function begins at the end of the ConstSpec or VarSpec
- // (ShortVarDecl for short variable declarations) and ends at the
- // end of the innermost containing block."
- scopePos := s.End()
- for i, name := range s.Names {
- check.declare(check.scope, name, lhs[i], scopePos)
- }
+ case varDecl:
+ top := len(check.delayed)
- case token.VAR:
- top := len(check.delayed)
+ lhs0 := make([]*Var, len(d.spec.Names))
+ for i, name := range d.spec.Names {
+ lhs0[i] = NewVar(name.Pos(), pkg, name.Name, nil)
+ }
- lhs0 := make([]*Var, len(s.Names))
- for i, name := range s.Names {
- lhs0[i] = NewVar(name.Pos(), pkg, name.Name, nil)
+ // initialize all variables
+ for i, obj := range lhs0 {
+ var lhs []*Var
+ var init ast.Expr
+ switch len(d.spec.Values) {
+ case len(d.spec.Names):
+ // lhs and rhs match
+ init = d.spec.Values[i]
+ case 1:
+ // rhs is expected to be a multi-valued expression
+ lhs = lhs0
+ init = d.spec.Values[0]
+ default:
+ if i < len(d.spec.Values) {
+ init = d.spec.Values[i]
}
-
- // initialize all variables
- for i, obj := range lhs0 {
- var lhs []*Var
- var init ast.Expr
- switch len(s.Values) {
- case len(s.Names):
- // lhs and rhs match
- init = s.Values[i]
- case 1:
- // rhs is expected to be a multi-valued expression
- lhs = lhs0
- init = s.Values[0]
- default:
- if i < len(s.Values) {
- init = s.Values[i]
- }
- }
- check.varDecl(obj, lhs, s.Type, init)
- if len(s.Values) == 1 {
- // If we have a single lhs variable we are done either way.
- // If we have a single rhs expression, it must be a multi-
- // valued expression, in which case handling the first lhs
- // variable will cause all lhs variables to have a type
- // assigned, and we are done as well.
- if debug {
- for _, obj := range lhs0 {
- assert(obj.typ != nil)
- }
- }
- break
+ }
+ check.varDecl(obj, lhs, d.spec.Type, init)
+ if len(d.spec.Values) == 1 {
+ // If we have a single lhs variable we are done either way.
+ // If we have a single rhs expression, it must be a multi-
+ // valued expression, in which case handling the first lhs
+ // variable will cause all lhs variables to have a type
+ // assigned, and we are done as well.
+ if debug {
+ for _, obj := range lhs0 {
+ assert(obj.typ != nil)
}
}
-
- check.arityMatch(s, nil)
-
- // process function literals in init expressions before scope changes
- check.processDelayed(top)
-
- // declare all variables
- // (only at this point are the variable scopes (parents) set)
- scopePos := s.End() // see constant declarations
- for i, name := range s.Names {
- // see constant declarations
- check.declare(check.scope, name, lhs0[i], scopePos)
- }
-
- default:
- check.invalidAST(s.Pos(), "invalid token %s", d.Tok)
+ break
}
+ }
- case *ast.TypeSpec:
- obj := NewTypeName(s.Name.Pos(), pkg, s.Name.Name, nil)
- // spec: "The scope of a type identifier declared inside a function
- // begins at the identifier in the TypeSpec and ends at the end of
- // the innermost containing block."
- scopePos := s.Name.Pos()
- check.declare(check.scope, s.Name, obj, scopePos)
- // mark and unmark type before calling typeDecl; its type is still nil (see Checker.objDecl)
- obj.setColor(grey + color(check.push(obj)))
- check.typeDecl(obj, s.Type, nil, s.Assign.IsValid())
- check.pop().setColor(black)
- default:
- check.invalidAST(s.Pos(), "const, type, or var declaration expected")
+ // process function literals in init expressions before scope changes
+ check.processDelayed(top)
+
+ // declare all variables
+ // (only at this point are the variable scopes (parents) set)
+ scopePos := d.spec.End() // see constant declarations
+ for i, name := range d.spec.Names {
+ // see constant declarations
+ check.declare(check.scope, name, lhs0[i], scopePos)
}
- }
- default:
- check.invalidAST(d.Pos(), "unknown ast.Decl node %T", d)
- }
+ case typeDecl:
+ obj := NewTypeName(d.spec.Name.Pos(), pkg, d.spec.Name.Name, nil)
+ // spec: "The scope of a type identifier declared inside a function
+ // begins at the identifier in the TypeSpec and ends at the end of
+ // the innermost containing block."
+ scopePos := d.spec.Name.Pos()
+ check.declare(check.scope, d.spec.Name, obj, scopePos)
+ // mark and unmark type before calling typeDecl; its type is still nil (see Checker.objDecl)
+ obj.setColor(grey + color(check.push(obj)))
+ check.typeDecl(obj, d.spec.Type, nil, d.spec.Assign.IsValid())
+ check.pop().setColor(black)
+ default:
+ check.invalidAST(d.node().Pos(), "unknown ast.Decl node %T", d.node())
+ }
+ })
}
// we get "." as the directory which is what we would want.
fileDir := dir(check.fset.Position(file.Name.Pos()).Filename)
- for _, decl := range file.Decls {
- switch d := decl.(type) {
- case *ast.BadDecl:
- // ignore
-
- case *ast.GenDecl:
- var last *ast.ValueSpec // last ValueSpec with type or init exprs seen
- for iota, spec := range d.Specs {
- switch s := spec.(type) {
- case *ast.ImportSpec:
- // import package
- path, err := validatedImportPath(s.Path.Value)
- if err != nil {
- check.errorf(s.Path.Pos(), "invalid import path (%s)", err)
- continue
- }
+ check.walkDecls(file.Decls, func(d decl) {
+ switch d := d.(type) {
+ case importDecl:
+ // import package
+ path, err := validatedImportPath(d.spec.Path.Value)
+ if err != nil {
+ check.errorf(d.spec.Path.Pos(), "invalid import path (%s)", err)
+ return
+ }
- imp := check.importPackage(s.Path.Pos(), path, fileDir)
- if imp == nil {
- continue
- }
+ imp := check.importPackage(d.spec.Path.Pos(), path, fileDir)
+ if imp == nil {
+ return
+ }
- // add package to list of explicit imports
- // (this functionality is provided as a convenience
- // for clients; it is not needed for type-checking)
- if !pkgImports[imp] {
- pkgImports[imp] = true
- pkg.imports = append(pkg.imports, imp)
- }
+ // add package to list of explicit imports
+ // (this functionality is provided as a convenience
+ // for clients; it is not needed for type-checking)
+ if !pkgImports[imp] {
+ pkgImports[imp] = true
+ pkg.imports = append(pkg.imports, imp)
+ }
- // local name overrides imported package name
- name := imp.name
- if s.Name != nil {
- name = s.Name.Name
- if path == "C" {
- // match cmd/compile (not prescribed by spec)
- check.errorf(s.Name.Pos(), `cannot rename import "C"`)
- continue
- }
- if name == "init" {
- check.errorf(s.Name.Pos(), "cannot declare init - must be func")
- continue
- }
- }
+ // local name overrides imported package name
+ name := imp.name
+ if d.spec.Name != nil {
+ name = d.spec.Name.Name
+ if path == "C" {
+ // match cmd/compile (not prescribed by spec)
+ check.errorf(d.spec.Name.Pos(), `cannot rename import "C"`)
+ return
+ }
+ if name == "init" {
+ check.errorf(d.spec.Name.Pos(), "cannot declare init - must be func")
+ return
+ }
+ }
- obj := NewPkgName(s.Pos(), pkg, name, imp)
- if s.Name != nil {
- // in a dot-import, the dot represents the package
- check.recordDef(s.Name, obj)
- } else {
- check.recordImplicit(s, obj)
- }
+ obj := NewPkgName(d.spec.Pos(), pkg, name, imp)
+ if d.spec.Name != nil {
+ // in a dot-import, the dot represents the package
+ check.recordDef(d.spec.Name, obj)
+ } else {
+ check.recordImplicit(d.spec, obj)
+ }
- if path == "C" {
- // match cmd/compile (not prescribed by spec)
- obj.used = true
- }
+ if path == "C" {
+ // match cmd/compile (not prescribed by spec)
+ obj.used = true
+ }
- // add import to file scope
- if name == "." {
- // merge imported scope with file scope
- for _, obj := range imp.scope.elems {
- // A package scope may contain non-exported objects,
- // do not import them!
- if obj.Exported() {
- // declare dot-imported object
- // (Do not use check.declare because it modifies the object
- // via Object.setScopePos, which leads to a race condition;
- // the object may be imported into more than one file scope
- // concurrently. See issue #32154.)
- if alt := fileScope.Insert(obj); alt != nil {
- check.errorf(s.Name.Pos(), "%s redeclared in this block", obj.Name())
- check.reportAltDecl(alt)
- }
- }
+ // add import to file scope
+ if name == "." {
+ // merge imported scope with file scope
+ for _, obj := range imp.scope.elems {
+ // A package scope may contain non-exported objects,
+ // do not import them!
+ if obj.Exported() {
+ // declare dot-imported object
+ // (Do not use check.declare because it modifies the object
+ // via Object.setScopePos, which leads to a race condition;
+ // the object may be imported into more than one file scope
+ // concurrently. See issue #32154.)
+ if alt := fileScope.Insert(obj); alt != nil {
+ check.errorf(d.spec.Name.Pos(), "%s redeclared in this block", obj.Name())
+ check.reportAltDecl(alt)
}
- // add position to set of dot-import positions for this file
- // (this is only needed for "imported but not used" errors)
- check.addUnusedDotImport(fileScope, imp, s.Pos())
- } else {
- // declare imported package object in file scope
- // (no need to provide s.Name since we called check.recordDef earlier)
- check.declare(fileScope, nil, obj, token.NoPos)
}
+ }
+ // add position to set of dot-import positions for this file
+ // (this is only needed for "imported but not used" errors)
+ check.addUnusedDotImport(fileScope, imp, d.spec.Pos())
+ } else {
+ // declare imported package object in file scope
+ // (no need to provide s.Name since we called check.recordDef earlier)
+ check.declare(fileScope, nil, obj, token.NoPos)
+ }
+ case constDecl:
+ // declare all constants
+ for i, name := range d.spec.Names {
+ obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(d.iota)))
+
+ var init ast.Expr
+ if i < len(d.init) {
+ init = d.init[i]
+ }
- case *ast.ValueSpec:
- switch d.Tok {
- case token.CONST:
- // determine which initialization expressions to use
- switch {
- case s.Type != nil || len(s.Values) > 0:
- last = s
- case last == nil:
- last = new(ast.ValueSpec) // make sure last exists
- }
-
- // declare all constants
- for i, name := range s.Names {
- obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(iota)))
-
- var init ast.Expr
- if i < len(last.Values) {
- init = last.Values[i]
- }
-
- d := &declInfo{file: fileScope, typ: last.Type, init: init}
- check.declarePkgObj(name, obj, d)
- }
-
- check.arityMatch(s, last)
-
- case token.VAR:
- lhs := make([]*Var, len(s.Names))
- // If there's exactly one rhs initializer, use
- // the same declInfo d1 for all lhs variables
- // so that each lhs variable depends on the same
- // rhs initializer (n:1 var declaration).
- var d1 *declInfo
- if len(s.Values) == 1 {
- // The lhs elements are only set up after the for loop below,
- // but that's ok because declareVar only collects the declInfo
- // for a later phase.
- d1 = &declInfo{file: fileScope, lhs: lhs, typ: s.Type, init: s.Values[0]}
- }
-
- // declare all variables
- for i, name := range s.Names {
- obj := NewVar(name.Pos(), pkg, name.Name, nil)
- lhs[i] = obj
-
- d := d1
- if d == nil {
- // individual assignments
- var init ast.Expr
- if i < len(s.Values) {
- init = s.Values[i]
- }
- d = &declInfo{file: fileScope, typ: s.Type, init: init}
- }
-
- check.declarePkgObj(name, obj, d)
- }
+ d := &declInfo{file: fileScope, typ: d.typ, init: init}
+ check.declarePkgObj(name, obj, d)
+ }
- check.arityMatch(s, nil)
+ case varDecl:
+ lhs := make([]*Var, len(d.spec.Names))
+ // If there's exactly one rhs initializer, use
+ // the same declInfo d1 for all lhs variables
+ // so that each lhs variable depends on the same
+ // rhs initializer (n:1 var declaration).
+ var d1 *declInfo
+ if len(d.spec.Values) == 1 {
+ // The lhs elements are only set up after the for loop below,
+ // but that's ok because declareVar only collects the declInfo
+ // for a later phase.
+ d1 = &declInfo{file: fileScope, lhs: lhs, typ: d.spec.Type, init: d.spec.Values[0]}
+ }
- default:
- check.invalidAST(s.Pos(), "invalid token %s", d.Tok)
+ // declare all variables
+ for i, name := range d.spec.Names {
+ obj := NewVar(name.Pos(), pkg, name.Name, nil)
+ lhs[i] = obj
+
+ di := d1
+ if di == nil {
+ // individual assignments
+ var init ast.Expr
+ if i < len(d.spec.Values) {
+ init = d.spec.Values[i]
}
-
- case *ast.TypeSpec:
- obj := NewTypeName(s.Name.Pos(), pkg, s.Name.Name, nil)
- check.declarePkgObj(s.Name, obj, &declInfo{file: fileScope, typ: s.Type, alias: s.Assign.IsValid()})
-
- default:
- check.invalidAST(s.Pos(), "unknown ast.Spec node %T", s)
+ di = &declInfo{file: fileScope, typ: d.spec.Type, init: init}
}
- }
- case *ast.FuncDecl:
- name := d.Name.Name
- obj := NewFunc(d.Name.Pos(), pkg, name, nil)
- if d.Recv == nil {
+ check.declarePkgObj(name, obj, di)
+ }
+ case typeDecl:
+ obj := NewTypeName(d.spec.Name.Pos(), pkg, d.spec.Name.Name, nil)
+ check.declarePkgObj(d.spec.Name, obj, &declInfo{file: fileScope, typ: d.spec.Type, alias: d.spec.Assign.IsValid()})
+ case funcDecl:
+ info := &declInfo{file: fileScope, fdecl: d.decl}
+ name := d.decl.Name.Name
+ obj := NewFunc(d.decl.Name.Pos(), pkg, name, nil)
+ if d.decl.Recv == nil {
// regular function
if name == "init" {
// don't declare init functions in the package scope - they are invisible
obj.parent = pkg.scope
- check.recordDef(d.Name, obj)
+ check.recordDef(d.decl.Name, obj)
// init functions must have a body
- if d.Body == nil {
+ if d.decl.Body == nil {
check.softErrorf(obj.pos, "missing function body")
}
} else {
- check.declare(pkg.scope, d.Name, obj, token.NoPos)
+ check.declare(pkg.scope, d.decl.Name, obj, token.NoPos)
}
} else {
// method
if name != "_" {
methods = append(methods, obj)
}
- check.recordDef(d.Name, obj)
+ check.recordDef(d.decl.Name, obj)
}
- info := &declInfo{file: fileScope, fdecl: d}
// Methods are not package-level objects but we still track them in the
// object map so that we can handle them like regular functions (if the
// receiver is invalid); also we need their fdecl info when associating
// them with their receiver base type, below.
check.objMap[obj] = info
obj.setOrder(uint32(len(check.objMap)))
-
- default:
- check.invalidAST(d.Pos(), "unknown ast.Decl node %T", d)
}
- }
+ })
}
// verify that objects in package and file scopes have different names