diff options
Diffstat (limited to 'vendor/golang.org/x/tools/internal/aliases')
3 files changed, 166 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 0000000..c24c2ee --- /dev/null +++ b/vendor/golang.org/x/tools/internal/aliases/aliases.go @@ -0,0 +1,32 @@ +// 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. +// +// The enabled parameter determines whether the resulting [TypeName]'s +// type is an [types.Alias]. Its value must be the result of a call to +// [Enabled], which computes the effective value of +// GODEBUG=gotypesalias=... by invoking the type checker. The Enabled +// function is expensive and should be called once per task (e.g. +// package import), not once per call to NewAlias. +func NewAlias(enabled bool, 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 0000000..6652f7d --- /dev/null +++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go @@ -0,0 +1,35 @@ +// 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") } +func Rhs(alias *Alias) types.Type { panic("unreachable") } +func TypeParams(alias *Alias) *types.TypeParamList { panic("unreachable") } +func SetTypeParams(alias *Alias, tparams []*types.TypeParam) { panic("unreachable") } +func TypeArgs(alias *Alias) *types.TypeList { panic("unreachable") } +func Origin(alias *Alias) *Alias { panic("unreachable") } + +// Unalias returns the type t for go <=1.21. +func Unalias(t types.Type) types.Type { return t } + +func newAlias(name *types.TypeName, rhs types.Type) *Alias { panic("unreachable") } + +// Enabled reports whether [NewAlias] should create [types.Alias] types. +// +// Before go1.22, this function always returns false. +func Enabled() bool { return false } 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 0000000..3ef1afe --- /dev/null +++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go @@ -0,0 +1,99 @@ +// 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" +) + +// Alias is an alias of types.Alias. +type Alias = types.Alias + +// Rhs returns the type on the right-hand side of the alias declaration. +func Rhs(alias *Alias) types.Type { + if alias, ok := any(alias).(interface{ Rhs() types.Type }); ok { + return alias.Rhs() // go1.23+ + } + + // go1.22's Alias didn't have the Rhs method, + // so Unalias is the best we can do. + return Unalias(alias) +} + +// TypeParams returns the type parameter list of the alias. +func TypeParams(alias *Alias) *types.TypeParamList { + if alias, ok := any(alias).(interface{ TypeParams() *types.TypeParamList }); ok { + return alias.TypeParams() // go1.23+ + } + return nil +} + +// SetTypeParams sets the type parameters of the alias type. +func SetTypeParams(alias *Alias, tparams []*types.TypeParam) { + if alias, ok := any(alias).(interface { + SetTypeParams(tparams []*types.TypeParam) + }); ok { + alias.SetTypeParams(tparams) // go1.23+ + } else if len(tparams) > 0 { + panic("cannot set type parameters of an Alias type in go1.22") + } +} + +// TypeArgs returns the type arguments used to instantiate the Alias type. +func TypeArgs(alias *Alias) *types.TypeList { + if alias, ok := any(alias).(interface{ TypeArgs() *types.TypeList }); ok { + return alias.TypeArgs() // go1.23+ + } + return nil // empty (go1.22) +} + +// Origin returns the generic Alias type of which alias is an instance. +// If alias is not an instance of a generic alias, Origin returns alias. +func Origin(alias *Alias) *Alias { + if alias, ok := any(alias).(interface{ Origin() *types.Alias }); ok { + return alias.Origin() // go1.23+ + } + return alias // not an instance of a generic alias (go1.22) +} + +// 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 reports whether [NewAlias] should create [types.Alias] types. +// +// This function is expensive! Call it sparingly. +func Enabled() bool { + // The only reliable way to compute the answer is to invoke go/types. + // We don't parse the GODEBUG environment variable, because + // (a) it's tricky to do so in a manner that is consistent + // with the godebug package; in particular, a simple + // substring check is not good enough. The value is a + // rightmost-wins list of options. But more importantly: + // (b) it is impossible to detect changes to the effective + // setting caused by os.Setenv("GODEBUG"), as happens in + // many tests. Therefore any attempt to cache the result + // is just incorrect. + 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) + _, enabled := pkg.Scope().Lookup("A").Type().(*types.Alias) + return enabled +} |