diff options
author | Robert Griesemer <gri@golang.org> | 2021-05-20 14:53:21 -0700 |
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committer | Robert Griesemer <gri@golang.org> | 2021-05-21 15:26:27 +0000 |
commit | 243076da64d251853ed7a69ce770e9fa71b5bf0d (patch) | |
tree | a5d31af639dbff7b8aa03d16c7779499aeb6e26f /src/cmd/compile/internal/types2/typexpr.go | |
parent | cfe0250497aa2eaa7d3a9a56d815bfa1f4b9b8b5 (diff) | |
download | go-243076da64d251853ed7a69ce770e9fa71b5bf0d.tar.gz go-243076da64d251853ed7a69ce770e9fa71b5bf0d.zip |
[dev.typeparams] cmd/compile/internal/types2: move signature checking into separate file
This only moves functionality from one file into another.
Except for import adjustments there are no changes to the
code.
Change-Id: Id0d20a7537f20abe3a257ad3f550b0cb4499598c
Reviewed-on: https://go-review.googlesource.com/c/go/+/321590
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Diffstat (limited to 'src/cmd/compile/internal/types2/typexpr.go')
-rw-r--r-- | src/cmd/compile/internal/types2/typexpr.go | 304 |
1 files changed, 0 insertions, 304 deletions
diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go index 2352030b9b..b27b2a00df 100644 --- a/src/cmd/compile/internal/types2/typexpr.go +++ b/src/cmd/compile/internal/types2/typexpr.go @@ -13,9 +13,6 @@ import ( "strings" ) -// Disabled by default, but enabled when running tests (via types_test.go). -var acceptMethodTypeParams bool - // ident type-checks identifier e and initializes x with the value or type of e. // If an error occurred, x.mode is set to invalid. // For the meaning of def, see Checker.definedType, below. @@ -196,238 +193,6 @@ func (check *Checker) genericType(e syntax.Expr, reportErr bool) Type { return typ } -// isubst returns an x with identifiers substituted per the substitution map smap. -// isubst only handles the case of (valid) method receiver type expressions correctly. -func isubst(x syntax.Expr, smap map[*syntax.Name]*syntax.Name) syntax.Expr { - switch n := x.(type) { - case *syntax.Name: - if alt := smap[n]; alt != nil { - return alt - } - // case *syntax.StarExpr: - // X := isubst(n.X, smap) - // if X != n.X { - // new := *n - // new.X = X - // return &new - // } - case *syntax.Operation: - if n.Op == syntax.Mul && n.Y == nil { - X := isubst(n.X, smap) - if X != n.X { - new := *n - new.X = X - return &new - } - } - case *syntax.IndexExpr: - Index := isubst(n.Index, smap) - if Index != n.Index { - new := *n - new.Index = Index - return &new - } - case *syntax.ListExpr: - var elems []syntax.Expr - for i, elem := range n.ElemList { - new := isubst(elem, smap) - if new != elem { - if elems == nil { - elems = make([]syntax.Expr, len(n.ElemList)) - copy(elems, n.ElemList) - } - elems[i] = new - } - } - if elems != nil { - new := *n - new.ElemList = elems - return &new - } - case *syntax.ParenExpr: - return isubst(n.X, smap) // no need to keep parentheses - default: - // Other receiver type expressions are invalid. - // It's fine to ignore those here as they will - // be checked elsewhere. - } - return x -} - -// 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") - check.scope.isFunc = true - check.recordScope(ftyp, check.scope) - sig.scope = check.scope - defer check.closeScope() - - var recvTyp syntax.Expr // rewritten receiver type; valid if != nil - if recvPar != nil { - // collect generic receiver type parameters, if any - // - a receiver type parameter is like any other type parameter, except that it is declared implicitly - // - the receiver specification acts as local declaration for its type parameters, which may be blank - _, rname, rparams := check.unpackRecv(recvPar.Type, true) - if len(rparams) > 0 { - // Blank identifiers don't get declared and regular type-checking of the instantiated - // parameterized receiver type expression fails in Checker.collectParams of receiver. - // Identify blank type parameters and substitute each with a unique new identifier named - // "n_" (where n is the parameter index) and which cannot conflict with any user-defined - // name. - var smap map[*syntax.Name]*syntax.Name // substitution map from "_" to "!n" identifiers - for i, p := range rparams { - if p.Value == "_" { - new := *p - new.Value = fmt.Sprintf("%d_", i) - rparams[i] = &new // use n_ identifier instead of _ so it can be looked up - if smap == nil { - smap = make(map[*syntax.Name]*syntax.Name) - } - smap[p] = &new - } - } - if smap != nil { - // blank identifiers were found => use rewritten receiver type - recvTyp = isubst(recvPar.Type, smap) - } - // TODO(gri) rework declareTypeParams - sig.rparams = nil - for _, rparam := range rparams { - sig.rparams = check.declareTypeParam(sig.rparams, rparam) - } - // determine receiver type to get its type parameters - // and the respective type parameter bounds - var recvTParams []*TypeName - if rname != nil { - // recv should be a Named type (otherwise an error is reported elsewhere) - // 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 := asNamed(check.genericType(rname, false)); recv != nil { - recvTParams = recv.tparams - } - } - // provide type parameter bounds - // - only do this if we have the right number (otherwise an error is reported elsewhere) - if len(sig.rparams) == len(recvTParams) { - // We have a list of *TypeNames but we need a list of Types. - list := make([]Type, len(sig.rparams)) - for i, t := range sig.rparams { - list[i] = t.typ - } - smap := makeSubstMap(recvTParams, list) - for i, tname := range sig.rparams { - bound := recvTParams[i].typ.(*TypeParam).bound - // bound is (possibly) parameterized in the context of the - // receiver type declaration. Substitute parameters for the - // current context. - // TODO(gri) should we assume now that bounds always exist? - // (no bound == empty interface) - if bound != nil { - bound = check.subst(tname.pos, bound, smap) - tname.typ.(*TypeParam).bound = bound - } - } - } - } - } - - if tparams != nil { - sig.tparams = check.collectTypeParams(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 - // declarations and then squash that scope into the parent scope (and report any redeclarations at - // that time). - scope := NewScope(check.scope, nopos, nopos, "function body (temp. scope)") - var recvList []*Var // TODO(gri) remove the need for making a list here - if recvPar != nil { - recvList, _ = check.collectParams(scope, []*syntax.Field{recvPar}, recvTyp, false) // use rewritten receiver type, if any - } - params, variadic := check.collectParams(scope, ftyp.ParamList, nil, true) - results, _ := check.collectParams(scope, ftyp.ResultList, nil, false) - scope.Squash(func(obj, alt Object) { - var err error_ - err.errorf(obj, "%s redeclared in this block", obj.Name()) - err.recordAltDecl(alt) - check.report(&err) - }) - - if recvPar != nil { - // recv parameter list present (may be empty) - // spec: "The receiver is specified via an extra parameter section preceding the - // method name. That parameter section must declare a single parameter, the receiver." - var recv *Var - switch len(recvList) { - case 0: - // error reported by resolver - 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") - fallthrough // continue with first receiver - case 1: - recv = recvList[0] - } - - // 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) - rtyp = expand(rtyp) - - // 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 t := rtyp; t != Typ[Invalid] { - var err string - if T := asNamed(t); T != nil { - // 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 = "" - } - } else { - switch u := optype(T).(type) { - case *Basic: - // unsafe.Pointer is treated like a regular pointer - if u.kind == UnsafePointer { - err = "unsafe.Pointer" - } - case *Pointer, *Interface: - err = "pointer or interface type" - } - } - } else if T := asBasic(t); T != nil { - 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 = "" - } - } else { - check.errorf(recv.pos, "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 - } - - sig.params = NewTuple(params...) - sig.results = NewTuple(results...) - sig.variadic = variadic -} - // goTypeName returns the Go type name for typ and // removes any occurrences of "types2." from that name. func goTypeName(typ Type) string { @@ -730,72 +495,3 @@ func (check *Checker) typeList(list []syntax.Expr) []Type { } return res } - -// collectParams declares the parameters of list in scope and returns the corresponding -// variable list. If type0 != nil, it is used instead of the first type in list. -func (check *Checker) collectParams(scope *Scope, list []*syntax.Field, type0 syntax.Expr, variadicOk bool) (params []*Var, variadic bool) { - if list == nil { - return - } - - var named, anonymous bool - - var typ Type - var prev syntax.Expr - for i, field := range list { - ftype := field.Type - // type-check type of grouped fields only once - if ftype != prev { - prev = ftype - if i == 0 && type0 != nil { - ftype = type0 - } - if t, _ := ftype.(*syntax.DotsType); t != nil { - ftype = t.Elem - if variadicOk && i == len(list)-1 { - variadic = true - } else { - check.softErrorf(t, "can only use ... with final parameter in list") - // ignore ... and continue - } - } - typ = check.varType(ftype) - } - // The parser ensures that f.Tag is nil and we don't - // care if a constructed AST contains a non-nil tag. - if field.Name != nil { - // named parameter - name := field.Name.Value - if name == "" { - check.error(field.Name, invalidAST+"anonymous parameter") - // ok to continue - } - par := NewParam(field.Name.Pos(), check.pkg, name, typ) - check.declare(scope, field.Name, par, scope.pos) - params = append(params, par) - named = true - } else { - // anonymous parameter - par := NewParam(field.Pos(), check.pkg, "", typ) - check.recordImplicit(field, par) - params = append(params, par) - anonymous = true - } - } - - if named && anonymous { - check.error(list[0], invalidAST+"list contains both named and anonymous parameters") - // ok to continue - } - - // For a variadic function, change the last parameter's type from T to []T. - // Since we type-checked T rather than ...T, we also need to retro-actively - // record the type for ...T. - if variadic { - last := params[len(params)-1] - last.typ = &Slice{elem: last.typ} - check.recordTypeAndValue(list[len(list)-1].Type, typexpr, last.typ, nil) - } - - return -} |