diff options
Diffstat (limited to 'vendor/golang.org/x/tools/internal/aliases')
3 files changed, 130 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/internal/aliases/aliases.go b/vendor/golang.org/x/tools/internal/aliases/aliases.go new file mode 100644 index 000000000..f89112c8e --- /dev/null +++ b/vendor/golang.org/x/tools/internal/aliases/aliases.go @@ -0,0 +1,28 @@ +// Copyright 2024 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. + +package aliases + +import ( + "go/token" + "go/types" +) + +// Package aliases defines backward compatible shims +// for the types.Alias type representation added in 1.22. +// This defines placeholders for x/tools until 1.26. + +// NewAlias creates a new TypeName in Package pkg that +// is an alias for the type rhs. +// +// When GoVersion>=1.22 and GODEBUG=gotypesalias=1, +// the Type() of the return value is a *types.Alias. +func NewAlias(pos token.Pos, pkg *types.Package, name string, rhs types.Type) *types.TypeName { + if enabled() { + tname := types.NewTypeName(pos, pkg, name, nil) + newAlias(tname, rhs) + return tname + } + return types.NewTypeName(pos, pkg, name, rhs) +} diff --git a/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go b/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go new file mode 100644 index 000000000..1872b56ff --- /dev/null +++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go @@ -0,0 +1,30 @@ +// Copyright 2024 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. + +//go:build !go1.22 +// +build !go1.22 + +package aliases + +import ( + "go/types" +) + +// Alias is a placeholder for a go/types.Alias for <=1.21. +// It will never be created by go/types. +type Alias struct{} + +func (*Alias) String() string { panic("unreachable") } + +func (*Alias) Underlying() types.Type { panic("unreachable") } + +func (*Alias) Obj() *types.TypeName { panic("unreachable") } + +// Unalias returns the type t for go <=1.21. +func Unalias(t types.Type) types.Type { return t } + +// Always false for go <=1.21. Ignores GODEBUG. +func enabled() bool { return false } + +func newAlias(name *types.TypeName, rhs types.Type) *Alias { panic("unreachable") } diff --git a/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go b/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go new file mode 100644 index 000000000..8b9211628 --- /dev/null +++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go @@ -0,0 +1,72 @@ +// Copyright 2024 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. + +//go:build go1.22 +// +build go1.22 + +package aliases + +import ( + "go/ast" + "go/parser" + "go/token" + "go/types" + "os" + "strings" + "sync" +) + +// Alias is an alias of types.Alias. +type Alias = types.Alias + +// Unalias is a wrapper of types.Unalias. +func Unalias(t types.Type) types.Type { return types.Unalias(t) } + +// newAlias is an internal alias around types.NewAlias. +// Direct usage is discouraged as the moment. +// Try to use NewAlias instead. +func newAlias(tname *types.TypeName, rhs types.Type) *Alias { + a := types.NewAlias(tname, rhs) + // TODO(go.dev/issue/65455): Remove kludgy workaround to set a.actual as a side-effect. + Unalias(a) + return a +} + +// enabled returns true when types.Aliases are enabled. +func enabled() bool { + // Use the gotypesalias value in GODEBUG if set. + godebug := os.Getenv("GODEBUG") + value := -1 // last set value. + for _, f := range strings.Split(godebug, ",") { + switch f { + case "gotypesalias=1": + value = 1 + case "gotypesalias=0": + value = 0 + } + } + switch value { + case 0: + return false + case 1: + return true + default: + return aliasesDefault() + } +} + +// aliasesDefault reports if aliases are enabled by default. +func aliasesDefault() bool { + // Dynamically check if Aliases will be produced from go/types. + aliasesDefaultOnce.Do(func() { + fset := token.NewFileSet() + f, _ := parser.ParseFile(fset, "a.go", "package p; type A = int", 0) + pkg, _ := new(types.Config).Check("p", fset, []*ast.File{f}, nil) + _, gotypesaliasDefault = pkg.Scope().Lookup("A").Type().(*types.Alias) + }) + return gotypesaliasDefault +} + +var gotypesaliasDefault bool +var aliasesDefaultOnce sync.Once |