diff options
Diffstat (limited to 'vendor/golang.org/x/tools/internal/aliases')
3 files changed, 46 insertions, 50 deletions
diff --git a/vendor/golang.org/x/tools/internal/aliases/aliases.go b/vendor/golang.org/x/tools/internal/aliases/aliases.go index f89112c8e..c24c2eee4 100644 --- a/vendor/golang.org/x/tools/internal/aliases/aliases.go +++ b/vendor/golang.org/x/tools/internal/aliases/aliases.go @@ -16,10 +16,14 @@ import ( // 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() { +// 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 diff --git a/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go b/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go index 1872b56ff..c027b9f31 100644 --- a/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go +++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go121.go @@ -15,16 +15,17 @@ import ( // It will never be created by go/types. type Alias struct{} -func (*Alias) String() string { panic("unreachable") } - +func (*Alias) String() string { panic("unreachable") } func (*Alias) Underlying() types.Type { panic("unreachable") } - -func (*Alias) Obj() *types.TypeName { panic("unreachable") } +func (*Alias) Obj() *types.TypeName { panic("unreachable") } +func Rhs(alias *Alias) types.Type { 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") } + +// 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 index 8b9211628..b32995484 100644 --- a/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go +++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go @@ -12,14 +12,22 @@ import ( "go/parser" "go/token" "go/types" - "os" - "strings" - "sync" ) // 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) +} + // Unalias is a wrapper of types.Unalias. func Unalias(t types.Type) types.Type { return types.Unalias(t) } @@ -33,40 +41,23 @@ func newAlias(tname *types.TypeName, rhs types.Type) *Alias { 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 +// 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 } - -var gotypesaliasDefault bool -var aliasesDefaultOnce sync.Once |