package types2
-import "cmd/compile/internal/syntax"
+import (
+ "cmd/compile/internal/syntax"
+ "fmt"
+ . "internal/types/errors"
+)
// ----------------------------------------------------------------------------
// API
// We then unpack the *Signature and use the scope for the literal body.
rparams *TypeParamList // receiver type parameters from left to right, or nil
tparams *TypeParamList // type parameters from left to right, or nil
- scope *Scope // function scope, present for package-local signatures
+ scope *Scope // function scope for package-local and non-instantiated signatures; nil otherwise
recv *Var // nil if not a method
params *Tuple // (incoming) parameters from left to right; or nil
results *Tuple // (outgoing) results from left to right; or nil
// NewSignatureType creates a new function type for the given receiver,
// receiver type parameters, type parameters, parameters, and results. If
// variadic is set, params must hold at least one parameter and the last
-// parameter must be of unnamed slice type. If recv is non-nil, typeParams must
-// be empty. If recvTypeParams is non-empty, recv must be non-nil.
+// parameter's core type must be of unnamed slice or bytestring type.
+// If recv is non-nil, typeParams must be empty. If recvTypeParams is
+// non-empty, recv must be non-nil.
func NewSignatureType(recv *Var, recvTypeParams, typeParams []*TypeParam, params, results *Tuple, variadic bool) *Signature {
if variadic {
n := params.Len()
if n == 0 {
panic("variadic function must have at least one parameter")
}
- if _, ok := params.At(n - 1).typ.(*Slice); !ok {
- panic("variadic parameter must be of unnamed slice type")
+ core := coreString(params.At(n - 1).typ)
+ if _, ok := core.(*Slice); !ok && !isString(core) {
+ panic(fmt.Sprintf("got %s, want variadic parameter with unnamed slice type or string as core type", core.String()))
}
}
sig := &Signature{recv: recv, params: params, results: results, variadic: variadic}
// RecvTypeParams returns the receiver type parameters of signature s, or nil.
func (s *Signature) RecvTypeParams() *TypeParamList { return s.rparams }
-// SetRecvTypeParams sets the receiver type params of signature s.
-func (s *Signature) SetRecvTypeParams(rparams []*TypeParam) { s.rparams = bindTParams(rparams) }
-
// Params returns the parameters of signature s, or nil.
func (s *Signature) Params() *Tuple { return s.params }
// ----------------------------------------------------------------------------
// Implementation
-// Disabled by default, but enabled when running tests (via types_test.go).
-var acceptMethodTypeParams bool
-
// funcType type-checks a function or method type.
func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams []*syntax.Field, ftyp *syntax.FuncType) {
check.openScope(ftyp, "function")
// lookup in the scope.
for i, p := range rparams {
if p.Value == "_" {
- tpar := sig.rparams.At(i)
if check.recvTParamMap == nil {
check.recvTParamMap = make(map[*syntax.Name]*TypeParam)
}
- check.recvTParamMap[p] = tpar
+ check.recvTParamMap[p] = tparams[i]
}
}
// determine receiver type to get its type parameters
// Also: Don't report an error via genericType since it will be reported
// again when we type-check the signature.
// TODO(gri) maybe the receiver should be marked as invalid instead?
- if recv, _ := check.genericType(rname, false).(*Named); recv != nil {
+ if recv := asNamed(check.genericType(rname, nil)); recv != nil {
recvTParams = recv.TypeParams().list()
}
}
// provide type parameter bounds
- // - only do this if we have the right number (otherwise an error is reported elsewhere)
- if sig.RecvTypeParams().Len() == len(recvTParams) {
- // We have a list of *TypeNames but we need a list of Types.
- list := make([]Type, sig.RecvTypeParams().Len())
- for i, t := range sig.RecvTypeParams().list() {
- list[i] = t
- check.mono.recordCanon(t, recvTParams[i])
- }
- smap := makeSubstMap(recvTParams, list)
- for i, tpar := range sig.RecvTypeParams().list() {
- bound := recvTParams[i].bound
- // bound is (possibly) parameterized in the context of the
- // receiver type declaration. Substitute parameters for the
- // current context.
- tpar.bound = check.subst(tpar.obj.pos, bound, smap, nil)
+ if len(tparams) == len(recvTParams) {
+ smap := makeRenameMap(recvTParams, tparams)
+ for i, tpar := range tparams {
+ recvTPar := recvTParams[i]
+ check.mono.recordCanon(tpar, recvTPar)
+ // recvTPar.bound is (possibly) parameterized in the context of the
+ // receiver type declaration. Substitute parameters for the current
+ // context.
+ tpar.bound = check.subst(tpar.obj.pos, recvTPar.bound, smap, nil, check.context())
}
+ } else if len(tparams) < len(recvTParams) {
+ // Reporting an error here is a stop-gap measure to avoid crashes in the
+ // compiler when a type parameter/argument cannot be inferred later. It
+ // may lead to follow-on errors (see issues go.dev/issue/51339, go.dev/issue/51343).
+ // TODO(gri) find a better solution
+ got := measure(len(tparams), "type parameter")
+ check.errorf(recvPar, BadRecv, "got %s, but receiver base type declares %d", got, len(recvTParams))
}
}
}
if tparams != nil {
+ // The parser will complain about invalid type parameters for methods.
check.collectTypeParams(&sig.tparams, tparams)
- // Always type-check method type parameters but complain if they are not enabled.
- // (A separate check is needed when type-checking interface method signatures because
- // they don't have a receiver specification.)
- if recvPar != nil && !acceptMethodTypeParams {
- check.error(ftyp, "methods cannot have type parameters")
- }
}
// Value (non-type) parameters' scope starts in the function body. Use a temporary scope for their
results, _ := check.collectParams(scope, ftyp.ResultList, false)
scope.Squash(func(obj, alt Object) {
var err error_
+ err.code = DuplicateDecl
err.errorf(obj, "%s redeclared in this block", obj.Name())
err.recordAltDecl(alt)
check.report(&err)
recv = NewParam(nopos, nil, "", Typ[Invalid]) // ignore recv below
default:
// more than one receiver
- check.error(recvList[len(recvList)-1].Pos(), "method must have exactly one receiver")
+ check.error(recvList[len(recvList)-1].Pos(), InvalidRecv, "method must have exactly one receiver")
fallthrough // continue with first receiver
case 1:
recv = recvList[0]
}
+ sig.recv = recv
- // TODO(gri) We should delay rtyp expansion to when we actually need the
- // receiver; thus all checks here should be delayed to later.
- rtyp, _ := deref(recv.typ)
-
- // spec: "The receiver type must be of the form T or *T where T is a type name."
- // (ignore invalid types - error was reported before)
- if rtyp != Typ[Invalid] {
- var err string
- switch T := rtyp.(type) {
+ // Delay validation of receiver type as it may cause premature expansion
+ // of types the receiver type is dependent on (see issues go.dev/issue/51232, go.dev/issue/51233).
+ check.later(func() {
+ // spec: "The receiver type must be of the form T or *T where T is a type name."
+ rtyp, _ := deref(recv.typ)
+ atyp := _Unalias(rtyp)
+ if !isValid(atyp) {
+ return // error was reported before
+ }
+ // spec: "The type denoted by T is called the receiver base type; it must not
+ // be a pointer or interface type and it must be declared in the same package
+ // as the method."
+ switch T := atyp.(type) {
case *Named:
- T.resolve(check.conf.Context)
// The receiver type may be an instantiated type referred to
// by an alias (which cannot have receiver parameters for now).
if T.TypeArgs() != nil && sig.RecvTypeParams() == nil {
- check.errorf(recv.pos, "cannot define methods on instantiated type %s", recv.typ)
+ check.errorf(recv, InvalidRecv, "cannot define new methods on instantiated type %s", rtyp)
break
}
- // spec: "The type denoted by T is called the receiver base type; it must not
- // be a pointer or interface type and it must be declared in the same package
- // as the method."
if T.obj.pkg != check.pkg {
- err = "type not defined in this package"
- if check.conf.CompilerErrorMessages {
- check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
- err = ""
+ check.errorf(recv, InvalidRecv, "cannot define new methods on non-local type %s", rtyp)
+ break
+ }
+ var cause string
+ switch u := T.under().(type) {
+ case *Basic:
+ // unsafe.Pointer is treated like a regular pointer
+ if u.kind == UnsafePointer {
+ cause = "unsafe.Pointer"
}
- } else {
- // The underlying type of a receiver base type can be a type parameter;
- // e.g. for methods with a generic receiver T[P] with type T[P any] P.
- underIs(T, func(u Type) bool {
- switch u := u.(type) {
- case *Basic:
- // unsafe.Pointer is treated like a regular pointer
- if u.kind == UnsafePointer {
- err = "unsafe.Pointer"
- return false
- }
- case *Pointer, *Interface:
- err = "pointer or interface type"
- return false
- }
- return true
- })
+ case *Pointer, *Interface:
+ cause = "pointer or interface type"
+ case *TypeParam:
+ // The underlying type of a receiver base type cannot be a
+ // type parameter: "type T[P any] P" is not a valid declaration.
+ unreachable()
}
- case *Basic:
- err = "basic or unnamed type"
- if check.conf.CompilerErrorMessages {
- check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
- err = ""
+ if cause != "" {
+ check.errorf(recv, InvalidRecv, "invalid receiver type %s (%s)", rtyp, cause)
}
+ case *Basic:
+ check.errorf(recv, InvalidRecv, "cannot define new methods on non-local type %s", rtyp)
default:
- check.errorf(recv.pos, "invalid receiver type %s", recv.typ)
+ check.errorf(recv, InvalidRecv, "invalid receiver type %s", recv.typ)
}
- if err != "" {
- check.errorf(recv.pos, "invalid receiver type %s (%s)", recv.typ, err)
- // ok to continue
- }
- }
- sig.recv = recv
+ }).describef(recv, "validate receiver %s", recv)
}
sig.params = NewTuple(params...)
if variadicOk && i == len(list)-1 {
variadic = true
} else {
- check.softErrorf(t, "can only use ... with final parameter in list")
+ check.softErrorf(t, MisplacedDotDotDot, "can only use ... with final parameter in list")
// ignore ... and continue
}
}
// named parameter
name := field.Name.Value
if name == "" {
- check.error(field.Name, invalidAST+"anonymous parameter")
+ check.error(field.Name, InvalidSyntaxTree, "anonymous parameter")
// ok to continue
}
par := NewParam(field.Name.Pos(), check.pkg, name, typ)
}
if named && anonymous {
- check.error(list[0], invalidAST+"list contains both named and anonymous parameters")
+ check.error(list[0], InvalidSyntaxTree, "list contains both named and anonymous parameters")
// ok to continue
}