//
// [underlying type]: https://go.dev/ref/spec#Underlying_types.
func (a *Alias) Underlying() Type { return unalias(a).Underlying() }

// Origin returns the generic Alias type of which a is an instance.
// If a is not an instance of a generic alias, Origin returns a.
func (a *Alias) Origin() *Alias { return a.orig }

// TypeParams returns the type parameters of the alias type a, or nil.

// instantiated types, this is same as the type name of the origin type.
func (t *Named) Obj() *TypeName {
	if t.inst == nil {
		return t.obj
	}
	return t.inst.orig.obj
}

// Origin returns the generic type from which the named type t is
// instantiated. If t is not an instantiated type, the result is t.
func (t *Named) Origin() *Named {
	if t.inst == nil {
		return t
	}
	return t.inst.orig

func identicalOrigin(x, y *Named) bool {
	// TODO(gri) is this correct?
	return x.Origin().obj == y.Origin().obj
}

// identicalInstance reports if two type instantiations are identical.
// Instantiations are identical if their origin and type arguments are
// identical.
func identicalInstance(xorig Type, xargs []Type, yorig Type, yargs []Type) bool {

	{"-g"},
	{"-ggdb"},
	{"-march=souza"},
	{"-mcpu=123"},
	{"-mfpu=123"},
	{"-mtune=happybirthday"},
	{"-pic"},
	{"-pthread"},
	{"-Wl,--hash-style=both"},
	{"-Wl,-rpath,foo"},
	{"-Wl,-rpath,$ORIGIN/foo"},
	{"-Wl,-R", "/foo"},
	{"-Wl,-R", "foo"},
	{"-Wl,-R,foo"},
	{"-Wl,--just-symbols=foo"},
	{"-Wl,--just-symbols,foo"},
	{"-Wl,--warn-error"},
	{"-Wl,--no-warn-error"},
	{"foo.so"},
	{"_世界.dll"},

	defer pp.Free()
	genssa(f, pp)
	// Check frame size again.
	// The check above included only the space needed for local variables.
	// After genssa, the space needed includes local variables and the callee arg region.
	// We must do this check prior to calling pp.Flush.
	// If there are any oversized stack frames,
	// the assembler may emit inscrutable complaints about invalid instructions.
	if pp.Text.To.Offset >= maxStackSize {

// scope.
//
// If ctxt is non-nil, it may be used to de-duplicate the instance against
// previous instances with the same identity. As a special case, generic
// *Signature origin types are only considered identical if they are pointer
// equivalent, so that instantiating distinct (but possibly identical)
// signatures will yield different instances. The use of a shared context does

The bits may have been replaced on the origin server, or an attacker may
have intercepted the download attempt.

For more information, see 'go help module-auth'.
`

const sumdbMismatch = `

SECURITY ERROR
This download does NOT match the one reported by the checksum server.
The bits may have been replaced on the origin server, or an attacker may
have intercepted the download attempt.

//	    Error      *ModuleError  // error loading module
//	    Sum        string        // checksum for path, version (as in go.sum)
//	    GoModSum   string        // checksum for go.mod (as in go.sum)
//	    Origin     any           // provenance of module
//	    Reuse      bool          // reuse of old module info is safe
//	}
//
//	type ModuleError struct {
//	    Err string // the error itself
//	}
//

implicitly pinned for the duration of the call. Go memory reachable from
these function arguments must be pinned as long as the C code has access
to it. Whether Go memory is pinned is a dynamic property of that memory
region; it has nothing to do with the type of the pointer.

Go values created by calling new, by taking the address of a composite
literal, or by taking the address of a local variable may also have their

// returns an array of substrings of s or an empty list if s contains only white space.
// Single quotes and double quotes are recognized to prevent splitting within the
// quoted region, and are removed from the resulting substrings. If a quote in s
// isn't closed err will be set and r will have the unclosed argument as the
// last element. The backslash is used for escaping.
//