[dev.typeparams] go/types: move embedding positions from Checker to Interface

This is a straightforward port of CL 331514 to go/types, with minor
adjustments for the different position API.

Change-Id: I714b3f1cd5a0e8d249912bb589d456885a87e167
Reviewed-on: https://go-review.googlesource.com/c/go/+/335030
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit is contained in:
Rob Findley 2021-07-16 09:34:34 -04:00 committed by Robert Findley
parent b98b8b9b5b
commit fe4f13404d
5 changed files with 30 additions and 45 deletions

View file

@ -85,12 +85,11 @@ type Checker struct {
fset *token.FileSet
pkg *Package
*Info
version version // accepted language version
nextID uint64 // unique Id for type parameters (first valid Id is 1)
objMap map[Object]*declInfo // maps package-level objects and (non-interface) methods to declaration info
impMap map[importKey]*Package // maps (import path, source directory) to (complete or fake) package
posMap map[*Interface][]token.Pos // maps interface types to lists of embedded interface positions
typMap map[string]*Named // maps an instantiated named type hash to a *Named type
version version // accepted language version
nextID uint64 // unique Id for type parameters (first valid Id is 1)
objMap map[Object]*declInfo // maps package-level objects and (non-interface) methods to declaration info
impMap map[importKey]*Package // maps (import path, source directory) to (complete or fake) package
typMap map[string]*Named // maps an instantiated named type hash to a *Named type
// pkgPathMap maps package names to the set of distinct import paths we've
// seen for that name, anywhere in the import graph. It is used for
@ -193,7 +192,6 @@ func NewChecker(conf *Config, fset *token.FileSet, pkg *Package, info *Info) *Ch
version: version,
objMap: make(map[Object]*declInfo),
impMap: make(map[importKey]*Package),
posMap: make(map[*Interface][]token.Pos),
typMap: make(map[string]*Named),
}
}

View file

@ -16,11 +16,18 @@ func (check *Checker) interfaceType(ityp *Interface, iface *ast.InterfaceType, d
var tlist []ast.Expr
var tname *ast.Ident // "type" name of first entry in a type list declaration
addEmbedded := func(pos token.Pos, typ Type) {
ityp.embeddeds = append(ityp.embeddeds, typ)
if ityp.embedPos == nil {
ityp.embedPos = new([]token.Pos)
}
*ityp.embedPos = append(*ityp.embedPos, pos)
}
for _, f := range iface.Methods.List {
if len(f.Names) == 0 {
// We have an embedded type; possibly a union of types.
ityp.embeddeds = append(ityp.embeddeds, parseUnion(check, flattenUnion(nil, f.Type)))
check.posMap[ityp] = append(check.posMap[ityp], f.Type.Pos())
addEmbedded(f.Type.Pos(), parseUnion(check, flattenUnion(nil, f.Type)))
continue
}
@ -92,10 +99,9 @@ func (check *Checker) interfaceType(ityp *Interface, iface *ast.InterfaceType, d
// type constraints
if tlist != nil {
ityp.embeddeds = append(ityp.embeddeds, parseUnion(check, tlist))
// Types T in a type list are added as ~T expressions but we don't
// have the position of the '~'. Use the first type position instead.
check.posMap[ityp] = append(check.posMap[ityp], tlist[0].(*ast.UnaryExpr).X.Pos())
// TODO(rfindley): this differs from types2 due to the use of Pos() below,
// which should actually be on the ~. Confirm that this position is correct.
addEmbedded(tlist[0].Pos(), parseUnion(check, tlist))
}
// All methods and embedded elements for this interface are collected;
@ -110,7 +116,7 @@ func (check *Checker) interfaceType(ityp *Interface, iface *ast.InterfaceType, d
// sort for API stability
sortMethods(ityp.methods)
sortTypes(ityp.embeddeds)
// (don't sort embeddeds: they must correspond to *embedPos entries)
// Compute type set with a non-nil *Checker as soon as possible
// to report any errors. Subsequent uses of type sets should be
@ -226,14 +232,13 @@ func newTypeSet(check *Checker, pos token.Pos, ityp *Interface) *TypeSet {
// collect embedded elements
var allTypes Type
var posList []token.Pos
if check != nil {
posList = check.posMap[ityp]
}
for i, typ := range ityp.embeddeds {
// The embedding position is nil for imported interfaces
// and also for interface copies after substitution (but
// in that case we don't need to report errors again).
var pos token.Pos // embedding position
if posList != nil {
pos = posList[i]
if ityp.embedPos != nil {
pos = (*ityp.embedPos)[i]
}
var types Type
switch t := under(typ).(type) {
@ -268,6 +273,7 @@ func newTypeSet(check *Checker, pos token.Pos, ityp *Interface) *TypeSet {
}
allTypes = intersect(allTypes, types)
}
ityp.embedPos = nil // not needed anymore (errors have been reported)
// process todo's (this only happens if check == nil)
for i := 0; i < len(todo); i += 2 {
@ -287,24 +293,6 @@ func newTypeSet(check *Checker, pos token.Pos, ityp *Interface) *TypeSet {
return ityp.tset
}
func sortTypes(list []Type) {
sort.Stable(byUniqueTypeName(list))
}
// byUniqueTypeName named type lists can be sorted by their unique type names.
type byUniqueTypeName []Type
func (a byUniqueTypeName) Len() int { return len(a) }
func (a byUniqueTypeName) Less(i, j int) bool { return sortName(a[i]) < sortName(a[j]) }
func (a byUniqueTypeName) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func sortName(t Type) string {
if named := asNamed(t); named != nil {
return named.obj.Id()
}
return ""
}
func sortMethods(list []*Func) {
sort.Sort(byUniqueMethodName(list))
}

View file

@ -27,7 +27,7 @@ func TestSizeof(t *testing.T) {
{Tuple{}, 12, 24},
{Signature{}, 44, 88},
{Union{}, 24, 48},
{Interface{}, 40, 80},
{Interface{}, 44, 88},
{Map{}, 16, 32},
{Chan{}, 12, 24},
{Named{}, 84, 160},

View file

@ -320,7 +320,6 @@ func (subst *subster) typ(typ Type) Type {
if subst.check == nil {
panic("internal error: cannot instantiate interfaces yet")
}
subst.check.posMap[iface] = subst.check.posMap[t] // satisfy completeInterface requirement
return iface
}

View file

@ -258,10 +258,11 @@ func (s *Signature) Variadic() bool { return s.variadic }
// An Interface represents an interface type.
type Interface struct {
obj Object // type name object defining this interface; or nil (for better error messages)
methods []*Func // ordered list of explicitly declared methods
embeddeds []Type // ordered list of explicitly embedded elements
complete bool // indicates that obj, methods, and embeddeds are set and type set can be computed
obj Object // type name object defining this interface; or nil (for better error messages)
methods []*Func // ordered list of explicitly declared methods
embeddeds []Type // ordered list of explicitly embedded elements
embedPos *[]token.Pos // positions of embedded elements; or nil (for error messages) - use pointer to save space
complete bool // indicates that obj, methods, and embeddeds are set and type set can be computed
tset *TypeSet // type set described by this interface, computed lazily
}
@ -326,7 +327,6 @@ func NewInterfaceType(methods []*Func, embeddeds []Type) *Interface {
// sort for API stability
sortMethods(methods)
sortTypes(embeddeds)
typ.methods = methods
typ.embeddeds = embeddeds