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// Copyright 2017 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 types
import (
"cmd/compile/internal/base"
"cmd/internal/src"
"fmt"
"internal/types/errors"
"sync"
)
// Object represents an ir.Node, but without needing to import cmd/compile/internal/ir,
// which would cause an import cycle. The uses in other packages must type assert
// values of type Object to ir.Node or a more specific type.
type Object interface {
Pos() src.XPos
Sym() *Sym
Type() *Type
}
//go:generate stringer -type Kind -trimprefix T type.go
// Kind describes a kind of type.
type Kind uint8
const (
Txxx Kind = iota
TINT8
TUINT8
TINT16
TUINT16
TINT32
TUINT32
TINT64
TUINT64
TINT
TUINT
TUINTPTR
TCOMPLEX64
TCOMPLEX128
TFLOAT32
TFLOAT64
TBOOL
TPTR
TFUNC
TSLICE
TARRAY
TSTRUCT
TCHAN
TMAP
TINTER
TFORW
TANY
TSTRING
TUNSAFEPTR
// pseudo-types for literals
TIDEAL // untyped numeric constants
TNIL
TBLANK
// pseudo-types used temporarily only during frame layout (CalcSize())
TFUNCARGS
TCHANARGS
// SSA backend types
TSSA // internal types used by SSA backend (flags, memory, etc.)
TTUPLE // a pair of types, used by SSA backend
TRESULTS // multiple types; the result of calling a function or method, with a memory at the end.
NTYPE
)
// ChanDir is whether a channel can send, receive, or both.
type ChanDir uint8
func (c ChanDir) CanRecv() bool { return c&Crecv != 0 }
func (c ChanDir) CanSend() bool { return c&Csend != 0 }
const (
// types of channel
// must match ../../../../reflect/type.go:/ChanDir
Crecv ChanDir = 1 << 0
Csend ChanDir = 1 << 1
Cboth ChanDir = Crecv | Csend
)
// Types stores pointers to predeclared named types.
//
// It also stores pointers to several special types:
// - Types[TANY] is the placeholder "any" type recognized by SubstArgTypes.
// - Types[TBLANK] represents the blank variable's type.
// - Types[TINTER] is the canonical "interface{}" type.
// - Types[TNIL] represents the predeclared "nil" value's type.
// - Types[TUNSAFEPTR] is package unsafe's Pointer type.
var Types [NTYPE]*Type
var (
// Predeclared alias types. These are actually created as distinct
// defined types for better error messages, but are then specially
// treated as identical to their respective underlying types.
AnyType *Type
ByteType *Type
RuneType *Type
// Predeclared error interface type.
ErrorType *Type
// Predeclared comparable interface type.
ComparableType *Type
// Types to represent untyped string and boolean constants.
UntypedString = newType(TSTRING)
UntypedBool = newType(TBOOL)
// Types to represent untyped numeric constants.
UntypedInt = newType(TIDEAL)
UntypedRune = newType(TIDEAL)
UntypedFloat = newType(TIDEAL)
UntypedComplex = newType(TIDEAL)
)
// A Type represents a Go type.
//
// There may be multiple unnamed types with identical structure. However, there must
// be a unique Type object for each unique named (defined) type. After noding, a
// package-level type can be looked up by building its unique symbol sym (sym =
// package.Lookup(name)) and checking sym.Def. If sym.Def is non-nil, the type
// already exists at package scope and is available at sym.Def.(*ir.Name).Type().
// Local types (which may have the same name as a package-level type) are
// distinguished by the value of vargen.
type Type struct {
// extra contains extra etype-specific fields.
// As an optimization, those etype-specific structs which contain exactly
// one pointer-shaped field are stored as values rather than pointers when possible.
//
// TMAP: *Map
// TFORW: *Forward
// TFUNC: *Func
// TSTRUCT: *Struct
// TINTER: *Interface
// TFUNCARGS: FuncArgs
// TCHANARGS: ChanArgs
// TCHAN: *Chan
// TPTR: Ptr
// TARRAY: *Array
// TSLICE: Slice
// TSSA: string
extra interface{}
// width is the width of this Type in bytes.
width int64 // valid if Align > 0
// list of base methods (excluding embedding)
methods Fields
// list of all methods (including embedding)
allMethods Fields
// canonical OTYPE node for a named type (should be an ir.Name node with same sym)
obj Object
// the underlying type (type literal or predeclared type) for a defined type
underlying *Type
// Cache of composite types, with this type being the element type.
cache struct {
ptr *Type // *T, or nil
slice *Type // []T, or nil
}
vargen int32 // unique name for OTYPE/ONAME
kind Kind // kind of type
align uint8 // the required alignment of this type, in bytes (0 means Width and Align have not yet been computed)
flags bitset8
// For defined (named) generic types, a pointer to the list of type params
// (in order) of this type that need to be instantiated. For instantiated
// generic types, this is the targs used to instantiate them. These targs
// may be typeparams (for re-instantiated types such as Value[T2]) or
// concrete types (for fully instantiated types such as Value[int]).
// rparams is only set for named types that are generic or are fully
// instantiated from a generic type, and is otherwise set to nil.
// TODO(danscales): choose a better name.
rparams *[]*Type
}
func (*Type) CanBeAnSSAAux() {}
const (
typeNotInHeap = 1 << iota // type cannot be heap allocated
typeNoalg // suppress hash and eq algorithm generation
typeDeferwidth // width computation has been deferred and type is on deferredTypeStack
typeRecur
typeIsShape // represents a set of closely related types, for generics
typeHasShape // there is a shape somewhere in the type
)
func (t *Type) NotInHeap() bool { return t.flags&typeNotInHeap != 0 }
func (t *Type) Noalg() bool { return t.flags&typeNoalg != 0 }
func (t *Type) Deferwidth() bool { return t.flags&typeDeferwidth != 0 }
func (t *Type) Recur() bool { return t.flags&typeRecur != 0 }
func (t *Type) IsShape() bool { return t.flags&typeIsShape != 0 }
func (t *Type) HasShape() bool { return t.flags&typeHasShape != 0 }
func (t *Type) SetNotInHeap(b bool) { t.flags.set(typeNotInHeap, b) }
func (t *Type) SetNoalg(b bool) { t.flags.set(typeNoalg, b) }
func (t *Type) SetDeferwidth(b bool) { t.flags.set(typeDeferwidth, b) }
func (t *Type) SetRecur(b bool) { t.flags.set(typeRecur, b) }
// Should always do SetHasShape(true) when doing SetIsShape(true).
func (t *Type) SetIsShape(b bool) { t.flags.set(typeIsShape, b) }
func (t *Type) SetHasShape(b bool) { t.flags.set(typeHasShape, b) }
// Kind returns the kind of type t.
func (t *Type) Kind() Kind { return t.kind }
// Sym returns the name of type t.
func (t *Type) Sym() *Sym {
if t.obj != nil {
return t.obj.Sym()
}
return nil
}
// Underlying returns the underlying type of type t.
func (t *Type) Underlying() *Type { return t.underlying }
// Pos returns a position associated with t, if any.
// This should only be used for diagnostics.
func (t *Type) Pos() src.XPos {
if t.obj != nil {
return t.obj.Pos()
}
return src.NoXPos
}
func (t *Type) RParams() []*Type {
if t.rparams == nil {
return nil
}
return *t.rparams
}
func (t *Type) SetRParams(rparams []*Type) {
if len(rparams) == 0 {
base.Fatalf("Setting nil or zero-length rparams")
}
t.rparams = &rparams
// HasShape should be set if any type argument is or has a shape type.
for _, rparam := range rparams {
if rparam.HasShape() {
t.SetHasShape(true)
break
}
}
}
// IsFullyInstantiated reports whether t is a fully instantiated generic type; i.e. an
// instantiated generic type where all type arguments are non-generic or fully
// instantiated generic types.
func (t *Type) IsFullyInstantiated() bool {
return len(t.RParams()) > 0
}
// Map contains Type fields specific to maps.
type Map struct {
Key *Type // Key type
Elem *Type // Val (elem) type
Bucket *Type // internal struct type representing a hash bucket
Hmap *Type // internal struct type representing the Hmap (map header object)
Hiter *Type // internal struct type representing hash iterator state
}
// MapType returns t's extra map-specific fields.
func (t *Type) MapType() *Map {
t.wantEtype(TMAP)
return t.extra.(*Map)
}
// Forward contains Type fields specific to forward types.
type Forward struct {
Copyto []*Type // where to copy the eventual value to
Embedlineno src.XPos // first use of this type as an embedded type
}
// ForwardType returns t's extra forward-type-specific fields.
func (t *Type) ForwardType() *Forward {
t.wantEtype(TFORW)
return t.extra.(*Forward)
}
// Func contains Type fields specific to func types.
type Func struct {
Receiver *Type // function receiver
Results *Type // function results
Params *Type // function params
// Argwid is the total width of the function receiver, params, and results.
// It gets calculated via a temporary TFUNCARGS type.
// Note that TFUNC's Width is Widthptr.
Argwid int64
}
// FuncType returns t's extra func-specific fields.
func (t *Type) FuncType() *Func {
t.wantEtype(TFUNC)
return t.extra.(*Func)
}
// StructType contains Type fields specific to struct types.
type Struct struct {
fields Fields
// Maps have three associated internal structs (see struct MapType).
// Map links such structs back to their map type.
Map *Type
Funarg Funarg // type of function arguments for arg struct
}
// Funarg records the kind of function argument
type Funarg uint8
const (
FunargNone Funarg = iota
FunargRcvr // receiver
FunargParams // input parameters
FunargResults // output results
FunargTparams // type params
)
// StructType returns t's extra struct-specific fields.
func (t *Type) StructType() *Struct {
t.wantEtype(TSTRUCT)
return t.extra.(*Struct)
}
// Interface contains Type fields specific to interface types.
type Interface struct {
}
// Ptr contains Type fields specific to pointer types.
type Ptr struct {
Elem *Type // element type
}
// ChanArgs contains Type fields specific to TCHANARGS types.
type ChanArgs struct {
T *Type // reference to a chan type whose elements need a width check
}
// // FuncArgs contains Type fields specific to TFUNCARGS types.
type FuncArgs struct {
T *Type // reference to a func type whose elements need a width check
}
// Chan contains Type fields specific to channel types.
type Chan struct {
Elem *Type // element type
Dir ChanDir // channel direction
}
// ChanType returns t's extra channel-specific fields.
func (t *Type) ChanType() *Chan {
t.wantEtype(TCHAN)
return t.extra.(*Chan)
}
type Tuple struct {
first *Type
second *Type
// Any tuple with a memory type must put that memory type second.
}
// Results are the output from calls that will be late-expanded.
type Results struct {
Types []*Type // Last element is memory output from call.
}
// Array contains Type fields specific to array types.
type Array struct {
Elem *Type // element type
Bound int64 // number of elements; <0 if unknown yet
}
// Slice contains Type fields specific to slice types.
type Slice struct {
Elem *Type // element type
}
// A Field is a (Sym, Type) pairing along with some other information, and,
// depending on the context, is used to represent:
// - a field in a struct
// - a method in an interface or associated with a named type
// - a function parameter
type Field struct {
flags bitset8
Embedded uint8 // embedded field
Pos src.XPos
// Name of field/method/parameter. Can be nil for interface fields embedded
// in interfaces and unnamed parameters.
Sym *Sym
Type *Type // field type
Note string // literal string annotation
// For fields that represent function parameters, Nname points to the
// associated ONAME Node. For fields that represent methods, Nname points to
// the function name node.
Nname Object
// Offset in bytes of this field or method within its enclosing struct
// or interface Type. Exception: if field is function receiver, arg or
// result, then this is BOGUS_FUNARG_OFFSET; types does not know the Abi.
Offset int64
}
const (
fieldIsDDD = 1 << iota // field is ... argument
fieldNointerface
)
func (f *Field) IsDDD() bool { return f.flags&fieldIsDDD != 0 }
func (f *Field) Nointerface() bool { return f.flags&fieldNointerface != 0 }
func (f *Field) SetIsDDD(b bool) { f.flags.set(fieldIsDDD, b) }
func (f *Field) SetNointerface(b bool) { f.flags.set(fieldNointerface, b) }
// End returns the offset of the first byte immediately after this field.
func (f *Field) End() int64 {
return f.Offset + f.Type.width
}
// IsMethod reports whether f represents a method rather than a struct field.
func (f *Field) IsMethod() bool {
return f.Type.kind == TFUNC && f.Type.Recv() != nil
}
// Fields is a pointer to a slice of *Field.
// This saves space in Types that do not have fields or methods
// compared to a simple slice of *Field.
type Fields struct {
s *[]*Field
}
// Len returns the number of entries in f.
func (f *Fields) Len() int {
if f.s == nil {
return 0
}
return len(*f.s)
}
// Slice returns the entries in f as a slice.
// Changes to the slice entries will be reflected in f.
func (f *Fields) Slice() []*Field {
if f.s == nil {
return nil
}
return *f.s
}
// Index returns the i'th element of Fields.
// It panics if f does not have at least i+1 elements.
func (f *Fields) Index(i int) *Field {
return (*f.s)[i]
}
// Set sets f to a slice.
// This takes ownership of the slice.
func (f *Fields) Set(s []*Field) {
if len(s) == 0 {
f.s = nil
} else {
// Copy s and take address of t rather than s to avoid
// allocation in the case where len(s) == 0.
t := s
f.s = &t
}
}
// Append appends entries to f.
func (f *Fields) Append(s ...*Field) {
if f.s == nil {
f.s = new([]*Field)
}
*f.s = append(*f.s, s...)
}
// newType returns a new Type of the specified kind.
func newType(et Kind) *Type {
t := &Type{
kind: et,
width: BADWIDTH,
}
t.underlying = t
// TODO(josharian): lazily initialize some of these?
switch t.kind {
case TMAP:
t.extra = new(Map)
case TFORW:
t.extra = new(Forward)
case TFUNC:
t.extra = new(Func)
case TSTRUCT:
t.extra = new(Struct)
case TINTER:
t.extra = new(Interface)
case TPTR:
t.extra = Ptr{}
case TCHANARGS:
t.extra = ChanArgs{}
case TFUNCARGS:
t.extra = FuncArgs{}
case TCHAN:
t.extra = new(Chan)
case TTUPLE:
t.extra = new(Tuple)
case TRESULTS:
t.extra = new(Results)
}
return t
}
// NewArray returns a new fixed-length array Type.
func NewArray(elem *Type, bound int64) *Type {
if bound < 0 {
base.Fatalf("NewArray: invalid bound %v", bound)
}
t := newType(TARRAY)
t.extra = &Array{Elem: elem, Bound: bound}
if elem.HasShape() {
t.SetHasShape(true)
}
return t
}
// NewSlice returns the slice Type with element type elem.
func NewSlice(elem *Type) *Type {
if t := elem.cache.slice; t != nil {
if t.Elem() != elem {
base.Fatalf("elem mismatch")
}
if elem.HasShape() != t.HasShape() {
base.Fatalf("Incorrect HasShape flag for cached slice type")
}
return t
}
t := newType(TSLICE)
t.extra = Slice{Elem: elem}
elem.cache.slice = t
if elem.HasShape() {
t.SetHasShape(true)
}
return t
}
// NewChan returns a new chan Type with direction dir.
func NewChan(elem *Type, dir ChanDir) *Type {
t := newType(TCHAN)
ct := t.ChanType()
ct.Elem = elem
ct.Dir = dir
if elem.HasShape() {
t.SetHasShape(true)
}
return t
}
func NewTuple(t1, t2 *Type) *Type {
t := newType(TTUPLE)
t.extra.(*Tuple).first = t1
t.extra.(*Tuple).second = t2
if t1.HasShape() || t2.HasShape() {
t.SetHasShape(true)
}
return t
}
func newResults(types []*Type) *Type {
t := newType(TRESULTS)
t.extra.(*Results).Types = types
return t
}
func NewResults(types []*Type) *Type {
if len(types) == 1 && types[0] == TypeMem {
return TypeResultMem
}
return newResults(types)
}
func newSSA(name string) *Type {
t := newType(TSSA)
t.extra = name
return t
}
// NewMap returns a new map Type with key type k and element (aka value) type v.
func NewMap(k, v *Type) *Type {
t := newType(TMAP)
mt := t.MapType()
mt.Key = k
mt.Elem = v
if k.HasShape() || v.HasShape() {
t.SetHasShape(true)
}
return t
}
// NewPtrCacheEnabled controls whether *T Types are cached in T.
// Caching is disabled just before starting the backend.
// This allows the backend to run concurrently.
var NewPtrCacheEnabled = true
// NewPtr returns the pointer type pointing to t.
func NewPtr(elem *Type) *Type {
if elem == nil {
base.Fatalf("NewPtr: pointer to elem Type is nil")
}
if t := elem.cache.ptr; t != nil {
if t.Elem() != elem {
base.Fatalf("NewPtr: elem mismatch")
}
if elem.HasShape() != t.HasShape() {
base.Fatalf("Incorrect HasShape flag for cached pointer type")
}
return t
}
t := newType(TPTR)
t.extra = Ptr{Elem: elem}
t.width = int64(PtrSize)
t.align = uint8(PtrSize)
if NewPtrCacheEnabled {
elem.cache.ptr = t
}
if elem.HasShape() {
t.SetHasShape(true)
}
return t
}
// NewChanArgs returns a new TCHANARGS type for channel type c.
func NewChanArgs(c *Type) *Type {
t := newType(TCHANARGS)
t.extra = ChanArgs{T: c}
return t
}
// NewFuncArgs returns a new TFUNCARGS type for func type f.
func NewFuncArgs(f *Type) *Type {
t := newType(TFUNCARGS)
t.extra = FuncArgs{T: f}
return t
}
func NewField(pos src.XPos, sym *Sym, typ *Type) *Field {
f := &Field{
Pos: pos,
Sym: sym,
Type: typ,
Offset: BADWIDTH,
}
if typ == nil {
base.Fatalf("typ is nil")
}
return f
}
// SubstAny walks t, replacing instances of "any" with successive
// elements removed from types. It returns the substituted type.
func SubstAny(t *Type, types *[]*Type) *Type {
if t == nil {
return nil
}
switch t.kind {
default:
// Leave the type unchanged.
case TANY:
if len(*types) == 0 {
base.Fatalf("SubstArgTypes: not enough argument types")
}
t = (*types)[0]
*types = (*types)[1:]
case TPTR:
elem := SubstAny(t.Elem(), types)
if elem != t.Elem() {
t = t.copy()
t.extra = Ptr{Elem: elem}
}
case TARRAY:
elem := SubstAny(t.Elem(), types)
if elem != t.Elem() {
t = t.copy()
t.extra.(*Array).Elem = elem
}
case TSLICE:
elem := SubstAny(t.Elem(), types)
if elem != t.Elem() {
t = t.copy()
t.extra = Slice{Elem: elem}
}
case TCHAN:
elem := SubstAny(t.Elem(), types)
if elem != t.Elem() {
t = t.copy()
t.extra.(*Chan).Elem = elem
}
case TMAP:
key := SubstAny(t.Key(), types)
elem := SubstAny(t.Elem(), types)
if key != t.Key() || elem != t.Elem() {
t = t.copy()
t.extra.(*Map).Key = key
t.extra.(*Map).Elem = elem
}
case TFUNC:
recvs := SubstAny(t.Recvs(), types)
params := SubstAny(t.Params(), types)
results := SubstAny(t.Results(), types)
if recvs != t.Recvs() || params != t.Params() || results != t.Results() {
t = t.copy()
t.FuncType().Receiver = recvs
t.FuncType().Results = results
t.FuncType().Params = params
}
case TSTRUCT:
// Make a copy of all fields, including ones whose type does not change.
// This prevents aliasing across functions, which can lead to later
// fields getting their Offset incorrectly overwritten.
fields := t.FieldSlice()
nfs := make([]*Field, len(fields))
for i, f := range fields {
nft := SubstAny(f.Type, types)
nfs[i] = f.Copy()
nfs[i].Type = nft
}
t = t.copy()
t.SetFields(nfs)
}
return t
}
// copy returns a shallow copy of the Type.
func (t *Type) copy() *Type {
if t == nil {
return nil
}
nt := *t
// copy any *T Extra fields, to avoid aliasing
switch t.kind {
case TMAP:
x := *t.extra.(*Map)
nt.extra = &x
case TFORW:
x := *t.extra.(*Forward)
nt.extra = &x
case TFUNC:
x := *t.extra.(*Func)
nt.extra = &x
case TSTRUCT:
x := *t.extra.(*Struct)
nt.extra = &x
case TINTER:
x := *t.extra.(*Interface)
nt.extra = &x
case TCHAN:
x := *t.extra.(*Chan)
nt.extra = &x
case TARRAY:
x := *t.extra.(*Array)
nt.extra = &x
case TTUPLE, TSSA, TRESULTS:
base.Fatalf("ssa types cannot be copied")
}
// TODO(mdempsky): Find out why this is necessary and explain.
if t.underlying == t {
nt.underlying = &nt
}
return &nt
}
func (f *Field) Copy() *Field {
nf := *f
return &nf
}
func (t *Type) wantEtype(et Kind) {
if t.kind != et {
base.Fatalf("want %v, but have %v", et, t)
}
}
func (t *Type) Recvs() *Type { return t.FuncType().Receiver }
func (t *Type) Params() *Type { return t.FuncType().Params }
func (t *Type) Results() *Type { return t.FuncType().Results }
func (t *Type) NumRecvs() int { return t.FuncType().Receiver.NumFields() }
func (t *Type) NumParams() int { return t.FuncType().Params.NumFields() }
func (t *Type) NumResults() int { return t.FuncType().Results.NumFields() }
// IsVariadic reports whether function type t is variadic.
func (t *Type) IsVariadic() bool {
n := t.NumParams()
return n > 0 && t.Params().Field(n-1).IsDDD()
}
// Recv returns the receiver of function type t, if any.
func (t *Type) Recv() *Field {
s := t.Recvs()
if s.NumFields() == 0 {
return nil
}
return s.Field(0)
}
// RecvsParamsResults stores the accessor functions for a function Type's
// receiver, parameters, and result parameters, in that order.
// It can be used to iterate over all of a function's parameter lists.
var RecvsParamsResults = [3]func(*Type) *Type{
(*Type).Recvs, (*Type).Params, (*Type).Results,
}
// RecvsParams is like RecvsParamsResults, but omits result parameters.
var RecvsParams = [2]func(*Type) *Type{
(*Type).Recvs, (*Type).Params,
}
// ParamsResults is like RecvsParamsResults, but omits receiver parameters.
var ParamsResults = [2]func(*Type) *Type{
(*Type).Params, (*Type).Results,
}
// Key returns the key type of map type t.
func (t *Type) Key() *Type {
t.wantEtype(TMAP)
return t.extra.(*Map).Key
}
// Elem returns the type of elements of t.
// Usable with pointers, channels, arrays, slices, and maps.
func (t *Type) Elem() *Type {
switch t.kind {
case TPTR:
return t.extra.(Ptr).Elem
case TARRAY:
return t.extra.(*Array).Elem
case TSLICE:
return t.extra.(Slice).Elem
case TCHAN:
return t.extra.(*Chan).Elem
case TMAP:
return t.extra.(*Map).Elem
}
base.Fatalf("Type.Elem %s", t.kind)
return nil
}
// ChanArgs returns the channel type for TCHANARGS type t.
func (t *Type) ChanArgs() *Type {
t.wantEtype(TCHANARGS)
return t.extra.(ChanArgs).T
}
// FuncArgs returns the func type for TFUNCARGS type t.
func (t *Type) FuncArgs() *Type {
t.wantEtype(TFUNCARGS)
return t.extra.(FuncArgs).T
}
// IsFuncArgStruct reports whether t is a struct representing function parameters or results.
func (t *Type) IsFuncArgStruct() bool {
return t.kind == TSTRUCT && t.extra.(*Struct).Funarg != FunargNone
}
// Methods returns a pointer to the base methods (excluding embedding) for type t.
// These can either be concrete methods (for non-interface types) or interface
// methods (for interface types).
func (t *Type) Methods() *Fields {
return &t.methods
}
// AllMethods returns a pointer to all the methods (including embedding) for type t.
// For an interface type, this is the set of methods that are typically iterated
// over. For non-interface types, AllMethods() only returns a valid result after
// CalcMethods() has been called at least once.
func (t *Type) AllMethods() *Fields {
if t.kind == TINTER {
// Calculate the full method set of an interface type on the fly
// now, if not done yet.
CalcSize(t)
}
return &t.allMethods
}
// SetAllMethods sets the set of all methods (including embedding) for type t.
// Use this method instead of t.AllMethods().Set(), which might call CalcSize() on
// an uninitialized interface type.
func (t *Type) SetAllMethods(fs []*Field) {
t.allMethods.Set(fs)
}
// Fields returns the fields of struct type t.
func (t *Type) Fields() *Fields {
t.wantEtype(TSTRUCT)
return &t.extra.(*Struct).fields
}
// Field returns the i'th field of struct type t.
func (t *Type) Field(i int) *Field {
return t.Fields().Slice()[i]
}
// FieldSlice returns a slice of containing all fields of
// a struct type t.
func (t *Type) FieldSlice() []*Field {
return t.Fields().Slice()
}
// SetFields sets struct type t's fields to fields.
func (t *Type) SetFields(fields []*Field) {
// If we've calculated the width of t before,
// then some other type such as a function signature
// might now have the wrong type.
// Rather than try to track and invalidate those,
// enforce that SetFields cannot be called once
// t's width has been calculated.
if t.widthCalculated() {
base.Fatalf("SetFields of %v: width previously calculated", t)
}
t.wantEtype(TSTRUCT)
t.Fields().Set(fields)
}
// SetInterface sets the base methods of an interface type t.
func (t *Type) SetInterface(methods []*Field) {
t.wantEtype(TINTER)
t.Methods().Set(methods)
}
// ArgWidth returns the total aligned argument size for a function.
// It includes the receiver, parameters, and results.
func (t *Type) ArgWidth() int64 {
t.wantEtype(TFUNC)
return t.extra.(*Func).Argwid
}
func (t *Type) Size() int64 {
if t.kind == TSSA {
if t == TypeInt128 {
return 16
}
return 0
}
CalcSize(t)
return t.width
}
func (t *Type) Alignment() int64 {
CalcSize(t)
return int64(t.align)
}
func (t *Type) SimpleString() string {
return t.kind.String()
}
// Cmp is a comparison between values a and b.
//
// -1 if a < b
// 0 if a == b
// 1 if a > b
type Cmp int8
const (
CMPlt = Cmp(-1)
CMPeq = Cmp(0)
CMPgt = Cmp(1)
)
// Compare compares types for purposes of the SSA back
// end, returning a Cmp (one of CMPlt, CMPeq, CMPgt).
// The answers are correct for an optimizer
// or code generator, but not necessarily typechecking.
// The order chosen is arbitrary, only consistency and division
// into equivalence classes (Types that compare CMPeq) matters.
func (t *Type) Compare(x *Type) Cmp {
if x == t {
return CMPeq
}
return t.cmp(x)
}
func cmpForNe(x bool) Cmp {
if x {
return CMPlt
}
return CMPgt
}
func (r *Sym) cmpsym(s *Sym) Cmp {
if r == s {
return CMPeq
}
if r == nil {
return CMPlt
}
if s == nil {
return CMPgt
}
// Fast sort, not pretty sort
if len(r.Name) != len(s.Name) {
return cmpForNe(len(r.Name) < len(s.Name))
}
if r.Pkg != s.Pkg {
if len(r.Pkg.Prefix) != len(s.Pkg.Prefix) {
return cmpForNe(len(r.Pkg.Prefix) < len(s.Pkg.Prefix))
}
if r.Pkg.Prefix != s.Pkg.Prefix {
return cmpForNe(r.Pkg.Prefix < s.Pkg.Prefix)
}
}
if r.Name != s.Name {
return cmpForNe(r.Name < s.Name)
}
return CMPeq
}
// cmp compares two *Types t and x, returning CMPlt,
// CMPeq, CMPgt as t<x, t==x, t>x, for an arbitrary
// and optimizer-centric notion of comparison.
// TODO(josharian): make this safe for recursive interface types
// and use in signatlist sorting. See issue 19869.
func (t *Type) cmp(x *Type) Cmp {
// This follows the structure of function identical in identity.go
// with two exceptions.
// 1. Symbols are compared more carefully because a <,=,> result is desired.
// 2. Maps are treated specially to avoid endless recursion -- maps
// contain an internal data type not expressible in Go source code.
if t == x {
return CMPeq
}
if t == nil {
return CMPlt
}
if x == nil {
return CMPgt
}
if t.kind != x.kind {
return cmpForNe(t.kind < x.kind)
}
if t.obj != nil || x.obj != nil {
// Special case: we keep byte and uint8 separate
// for error messages. Treat them as equal.
switch t.kind {
case TUINT8:
if (t == Types[TUINT8] || t == ByteType) && (x == Types[TUINT8] || x == ByteType) {
return CMPeq
}
case TINT32:
if (t == Types[RuneType.kind] || t == RuneType) && (x == Types[RuneType.kind] || x == RuneType) {
return CMPeq
}
case TINTER:
// Make sure named any type matches any empty interface.
if t == AnyType && x.IsEmptyInterface() || x == AnyType && t.IsEmptyInterface() {
return CMPeq
}
}
}
if c := t.Sym().cmpsym(x.Sym()); c != CMPeq {
return c
}
if x.obj != nil {
// Syms non-nil, if vargens match then equal.
if t.vargen != x.vargen {
return cmpForNe(t.vargen < x.vargen)
}
return CMPeq
}
// both syms nil, look at structure below.
switch t.kind {
case TBOOL, TFLOAT32, TFLOAT64, TCOMPLEX64, TCOMPLEX128, TUNSAFEPTR, TUINTPTR,
TINT8, TINT16, TINT32, TINT64, TINT, TUINT8, TUINT16, TUINT32, TUINT64, TUINT:
return CMPeq
case TSSA:
tname := t.extra.(string)
xname := x.extra.(string)
// desire fast sorting, not pretty sorting.
if len(tname) == len(xname) {
if tname == xname {
return CMPeq
}
if tname < xname {
return CMPlt
}
return CMPgt
}
if len(tname) > len(xname) {
return CMPgt
}
return CMPlt
case TTUPLE:
xtup := x.extra.(*Tuple)
ttup := t.extra.(*Tuple)
if c := ttup.first.Compare(xtup.first); c != CMPeq {
return c
}
return ttup.second.Compare(xtup.second)
case TRESULTS:
xResults := x.extra.(*Results)
tResults := t.extra.(*Results)
xl, tl := len(xResults.Types), len(tResults.Types)
if tl != xl {
if tl < xl {
return CMPlt
}
return CMPgt
}
for i := 0; i < tl; i++ {
if c := tResults.Types[i].Compare(xResults.Types[i]); c != CMPeq {
return c
}
}
return CMPeq
case TMAP:
if c := t.Key().cmp(x.Key()); c != CMPeq {
return c
}
return t.Elem().cmp(x.Elem())
case TPTR, TSLICE:
// No special cases for these, they are handled
// by the general code after the switch.
case TSTRUCT:
if t.StructType().Map == nil {
if x.StructType().Map != nil {
return CMPlt // nil < non-nil
}
// to the fallthrough
} else if x.StructType().Map == nil {
return CMPgt // nil > non-nil
} else if t.StructType().Map.MapType().Bucket == t {
// Both have non-nil Map
// Special case for Maps which include a recursive type where the recursion is not broken with a named type
if x.StructType().Map.MapType().Bucket != x {
return CMPlt // bucket maps are least
}
return t.StructType().Map.cmp(x.StructType().Map)
} else if x.StructType().Map.MapType().Bucket == x {
return CMPgt // bucket maps are least
} // If t != t.Map.Bucket, fall through to general case
tfs := t.FieldSlice()
xfs := x.FieldSlice()
for i := 0; i < len(tfs) && i < len(xfs); i++ {
t1, x1 := tfs[i], xfs[i]
if t1.Embedded != x1.Embedded {
return cmpForNe(t1.Embedded < x1.Embedded)
}
if t1.Note != x1.Note {
return cmpForNe(t1.Note < x1.Note)
}
if c := t1.Sym.cmpsym(x1.Sym); c != CMPeq {
return c
}
if c := t1.Type.cmp(x1.Type); c != CMPeq {
return c
}
}
if len(tfs) != len(xfs) {
return cmpForNe(len(tfs) < len(xfs))
}
return CMPeq
case TINTER:
tfs := t.AllMethods().Slice()
xfs := x.AllMethods().Slice()
for i := 0; i < len(tfs) && i < len(xfs); i++ {
t1, x1 := tfs[i], xfs[i]
if c := t1.Sym.cmpsym(x1.Sym); c != CMPeq {
return c
}
if c := t1.Type.cmp(x1.Type); c != CMPeq {
return c
}
}
if len(tfs) != len(xfs) {
return cmpForNe(len(tfs) < len(xfs))
}
return CMPeq
case TFUNC:
for _, f := range RecvsParamsResults {
// Loop over fields in structs, ignoring argument names.
tfs := f(t).FieldSlice()
xfs := f(x).FieldSlice()
for i := 0; i < len(tfs) && i < len(xfs); i++ {
ta := tfs[i]
tb := xfs[i]
if ta.IsDDD() != tb.IsDDD() {
return cmpForNe(!ta.IsDDD())
}
if c := ta.Type.cmp(tb.Type); c != CMPeq {
return c
}
}
if len(tfs) != len(xfs) {
return cmpForNe(len(tfs) < len(xfs))
}
}
return CMPeq
case TARRAY:
if t.NumElem() != x.NumElem() {
return cmpForNe(t.NumElem() < x.NumElem())
}
case TCHAN:
if t.ChanDir() != x.ChanDir() {
return cmpForNe(t.ChanDir() < x.ChanDir())
}
default:
e := fmt.Sprintf("Do not know how to compare %v with %v", t, x)
panic(e)
}
// Common element type comparison for TARRAY, TCHAN, TPTR, and TSLICE.
return t.Elem().cmp(x.Elem())
}
// IsKind reports whether t is a Type of the specified kind.
func (t *Type) IsKind(et Kind) bool {
return t != nil && t.kind == et
}
func (t *Type) IsBoolean() bool {
return t.kind == TBOOL
}
var unsignedEType = [...]Kind{
TINT8: TUINT8,
TUINT8: TUINT8,
TINT16: TUINT16,
TUINT16: TUINT16,
TINT32: TUINT32,
TUINT32: TUINT32,
TINT64: TUINT64,
TUINT64: TUINT64,
TINT: TUINT,
TUINT: TUINT,
TUINTPTR: TUINTPTR,
}
// ToUnsigned returns the unsigned equivalent of integer type t.
func (t *Type) ToUnsigned() *Type {
if !t.IsInteger() {
base.Fatalf("unsignedType(%v)", t)
}
return Types[unsignedEType[t.kind]]
}
func (t *Type) IsInteger() bool {
switch t.kind {
case TINT8, TUINT8, TINT16, TUINT16, TINT32, TUINT32, TINT64, TUINT64, TINT, TUINT, TUINTPTR:
return true
}
return t == UntypedInt || t == UntypedRune
}
func (t *Type) IsSigned() bool {
switch t.kind {
case TINT8, TINT16, TINT32, TINT64, TINT:
return true
}
return false
}
func (t *Type) IsUnsigned() bool {
switch t.kind {
case TUINT8, TUINT16, TUINT32, TUINT64, TUINT, TUINTPTR:
return true
}
return false
}
func (t *Type) IsFloat() bool {
return t.kind == TFLOAT32 || t.kind == TFLOAT64 || t == UntypedFloat
}
func (t *Type) IsComplex() bool {
return t.kind == TCOMPLEX64 || t.kind == TCOMPLEX128 || t == UntypedComplex
}
// IsPtr reports whether t is a regular Go pointer type.
// This does not include unsafe.Pointer.
func (t *Type) IsPtr() bool {
return t.kind == TPTR
}
// IsPtrElem reports whether t is the element of a pointer (to t).
func (t *Type) IsPtrElem() bool {
return t.cache.ptr != nil
}
// IsUnsafePtr reports whether t is an unsafe pointer.
func (t *Type) IsUnsafePtr() bool {
return t.kind == TUNSAFEPTR
}
// IsUintptr reports whether t is a uintptr.
func (t *Type) IsUintptr() bool {
return t.kind == TUINTPTR
}
// IsPtrShaped reports whether t is represented by a single machine pointer.
// In addition to regular Go pointer types, this includes map, channel, and
// function types and unsafe.Pointer. It does not include array or struct types
// that consist of a single pointer shaped type.
// TODO(mdempsky): Should it? See golang.org/issue/15028.
func (t *Type) IsPtrShaped() bool {
return t.kind == TPTR || t.kind == TUNSAFEPTR ||
t.kind == TMAP || t.kind == TCHAN || t.kind == TFUNC
}
// HasNil reports whether the set of values determined by t includes nil.
func (t *Type) HasNil() bool {
switch t.kind {
case TCHAN, TFUNC, TINTER, TMAP, TNIL, TPTR, TSLICE, TUNSAFEPTR:
return true
}
return false
}
func (t *Type) IsString() bool {
return t.kind == TSTRING
}
func (t *Type) IsMap() bool {
return t.kind == TMAP
}
func (t *Type) IsChan() bool {
return t.kind == TCHAN
}
func (t *Type) IsSlice() bool {
return t.kind == TSLICE
}
func (t *Type) IsArray() bool {
return t.kind == TARRAY
}
func (t *Type) IsStruct() bool {
return t.kind == TSTRUCT
}
func (t *Type) IsInterface() bool {
return t.kind == TINTER
}
// IsEmptyInterface reports whether t is an empty interface type.
func (t *Type) IsEmptyInterface() bool {
return t.IsInterface() && t.AllMethods().Len() == 0
}
// IsScalar reports whether 't' is a scalar Go type, e.g.
// bool/int/float/complex. Note that struct and array types consisting
// of a single scalar element are not considered scalar, likewise
// pointer types are also not considered scalar.
func (t *Type) IsScalar() bool {
switch t.kind {
case TBOOL, TINT8, TUINT8, TINT16, TUINT16, TINT32,
TUINT32, TINT64, TUINT64, TINT, TUINT,
TUINTPTR, TCOMPLEX64, TCOMPLEX128, TFLOAT32, TFLOAT64:
return true
}
return false
}
func (t *Type) PtrTo() *Type {
return NewPtr(t)
}
func (t *Type) NumFields() int {
if t.kind == TRESULTS {
return len(t.extra.(*Results).Types)
}
return t.Fields().Len()
}
func (t *Type) FieldType(i int) *Type {
if t.kind == TTUPLE {
switch i {
case 0:
return t.extra.(*Tuple).first
case 1:
return t.extra.(*Tuple).second
default:
panic("bad tuple index")
}
}
if t.kind == TRESULTS {
return t.extra.(*Results).Types[i]
}
return t.Field(i).Type
}
func (t *Type) FieldOff(i int) int64 {
return t.Field(i).Offset
}
func (t *Type) FieldName(i int) string {
return t.Field(i).Sym.Name
}
func (t *Type) NumElem() int64 {
t.wantEtype(TARRAY)
return t.extra.(*Array).Bound
}
type componentsIncludeBlankFields bool
const (
IgnoreBlankFields componentsIncludeBlankFields = false
CountBlankFields componentsIncludeBlankFields = true
)
// NumComponents returns the number of primitive elements that compose t.
// Struct and array types are flattened for the purpose of counting.
// All other types (including string, slice, and interface types) count as one element.
// If countBlank is IgnoreBlankFields, then blank struct fields
// (and their comprised elements) are excluded from the count.
// struct { x, y [3]int } has six components; [10]struct{ x, y string } has twenty.
func (t *Type) NumComponents(countBlank componentsIncludeBlankFields) int64 {
switch t.kind {
case TSTRUCT:
if t.IsFuncArgStruct() {
base.Fatalf("NumComponents func arg struct")
}
var n int64
for _, f := range t.FieldSlice() {
if countBlank == IgnoreBlankFields && f.Sym.IsBlank() {
continue
}
n += f.Type.NumComponents(countBlank)
}
return n
case TARRAY:
return t.NumElem() * t.Elem().NumComponents(countBlank)
}
return 1
}
// SoleComponent returns the only primitive component in t,
// if there is exactly one. Otherwise, it returns nil.
// Components are counted as in NumComponents, including blank fields.
// Keep in sync with cmd/compile/internal/walk/convert.go:soleComponent.
func (t *Type) SoleComponent() *Type {
switch t.kind {
case TSTRUCT:
if t.IsFuncArgStruct() {
base.Fatalf("SoleComponent func arg struct")
}
if t.NumFields() != 1 {
return nil
}
return t.Field(0).Type.SoleComponent()
case TARRAY:
if t.NumElem() != 1 {
return nil
}
return t.Elem().SoleComponent()
}
return t
}
// ChanDir returns the direction of a channel type t.
// The direction will be one of Crecv, Csend, or Cboth.
func (t *Type) ChanDir() ChanDir {
t.wantEtype(TCHAN)
return t.extra.(*Chan).Dir
}
func (t *Type) IsMemory() bool {
if t == TypeMem || t.kind == TTUPLE && t.extra.(*Tuple).second == TypeMem {
return true
}
if t.kind == TRESULTS {
if types := t.extra.(*Results).Types; len(types) > 0 && types[len(types)-1] == TypeMem {
return true
}
}
return false
}
func (t *Type) IsFlags() bool { return t == TypeFlags }
func (t *Type) IsVoid() bool { return t == TypeVoid }
func (t *Type) IsTuple() bool { return t.kind == TTUPLE }
func (t *Type) IsResults() bool { return t.kind == TRESULTS }
// IsUntyped reports whether t is an untyped type.
func (t *Type) IsUntyped() bool {
if t == nil {
return false
}
if t == UntypedString || t == UntypedBool {
return true
}
switch t.kind {
case TNIL, TIDEAL:
return true
}
return false
}
// HasPointers reports whether t contains a heap pointer.
// Note that this function ignores pointers to not-in-heap types.
func (t *Type) HasPointers() bool {
return PtrDataSize(t) > 0
}
var recvType *Type
// FakeRecvType returns the singleton type used for interface method receivers.
func FakeRecvType() *Type {
if recvType == nil {
recvType = NewPtr(newType(TSTRUCT))
}
return recvType
}
func FakeRecv() *Field {
return NewField(base.AutogeneratedPos, nil, FakeRecvType())
}
var (
// TSSA types. HasPointers assumes these are pointer-free.
TypeInvalid = newSSA("invalid")
TypeMem = newSSA("mem")
TypeFlags = newSSA("flags")
TypeVoid = newSSA("void")
TypeInt128 = newSSA("int128")
TypeResultMem = newResults([]*Type{TypeMem})
)
func init() {
TypeInt128.width = 16
TypeInt128.align = 8
}
// NewNamed returns a new named type for the given type name. obj should be an
// ir.Name. The new type is incomplete (marked as TFORW kind), and the underlying
// type should be set later via SetUnderlying(). References to the type are
// maintained until the type is filled in, so those references can be updated when
// the type is complete.
func NewNamed(obj Object) *Type {
t := newType(TFORW)
t.obj = obj
if obj.Sym().Pkg == ShapePkg {
t.SetIsShape(true)
t.SetHasShape(true)
}
return t
}
// Obj returns the canonical type name node for a named type t, nil for an unnamed type.
func (t *Type) Obj() Object {
return t.obj
}
// typeGen tracks the number of function-scoped defined types that
// have been declared. It's used to generate unique linker symbols for
// their runtime type descriptors.
var typeGen int32
// SetVargen assigns a unique generation number to type t, which must
// be a defined type declared within function scope. The generation
// number is used to distinguish it from other similarly spelled
// defined types from the same package.
//
// TODO(mdempsky): Come up with a better solution.
func (t *Type) SetVargen() {
base.Assertf(t.Sym() != nil, "SetVargen on anonymous type %v", t)
base.Assertf(t.vargen == 0, "type %v already has Vargen %v", t, t.vargen)
typeGen++
t.vargen = typeGen
}
// SetUnderlying sets the underlying type of an incomplete type (i.e. type whose kind
// is currently TFORW). SetUnderlying automatically updates any types that were waiting
// for this type to be completed.
func (t *Type) SetUnderlying(underlying *Type) {
if underlying.kind == TFORW {
// This type isn't computed yet; when it is, update n.
underlying.ForwardType().Copyto = append(underlying.ForwardType().Copyto, t)
return
}
ft := t.ForwardType()
// TODO(mdempsky): Fix Type rekinding.
t.kind = underlying.kind
t.extra = underlying.extra
t.width = underlying.width
t.align = underlying.align
t.underlying = underlying.underlying
if underlying.NotInHeap() {
t.SetNotInHeap(true)
}
if underlying.HasShape() {
t.SetHasShape(true)
}
// spec: "The declared type does not inherit any methods bound
// to the existing type, but the method set of an interface
// type [...] remains unchanged."
if t.IsInterface() {
t.methods = underlying.methods
t.allMethods = underlying.allMethods
}
// Update types waiting on this type.
for _, w := range ft.Copyto {
w.SetUnderlying(t)
}
// Double-check use of type as embedded type.
if ft.Embedlineno.IsKnown() {
if t.IsPtr() || t.IsUnsafePtr() {
base.ErrorfAt(ft.Embedlineno, errors.InvalidPtrEmbed, "embedded type cannot be a pointer")
}
}
}
func fieldsHasShape(fields []*Field) bool {
for _, f := range fields {
if f.Type != nil && f.Type.HasShape() {
return true
}
}
return false
}
// newBasic returns a new basic type of the given kind.
func newBasic(kind Kind, obj Object) *Type {
t := newType(kind)
t.obj = obj
return t
}
// NewInterface returns a new interface for the given methods and
// embedded types. Embedded types are specified as fields with no Sym.
func NewInterface(methods []*Field) *Type {
t := newType(TINTER)
t.SetInterface(methods)
for _, f := range methods {
// f.Type could be nil for a broken interface declaration
if f.Type != nil && f.Type.HasShape() {
t.SetHasShape(true)
break
}
}
return t
}
const BOGUS_FUNARG_OFFSET = -1000000000
func unzeroFieldOffsets(f []*Field) {
for i := range f {
f[i].Offset = BOGUS_FUNARG_OFFSET // This will cause an explosion if it is not corrected
}
}
// NewSignature returns a new function type for the given receiver,
// parameters, and results, any of which may be nil.
func NewSignature(recv *Field, params, results []*Field) *Type {
var recvs []*Field
if recv != nil {
recvs = []*Field{recv}
}
t := newType(TFUNC)
ft := t.FuncType()
funargs := func(fields []*Field, funarg Funarg) *Type {
s := NewStruct(fields)
s.StructType().Funarg = funarg
return s
}
if recv != nil {
recv.Offset = BOGUS_FUNARG_OFFSET
}
unzeroFieldOffsets(params)
unzeroFieldOffsets(results)
ft.Receiver = funargs(recvs, FunargRcvr)
ft.Params = funargs(params, FunargParams)
ft.Results = funargs(results, FunargResults)
if fieldsHasShape(recvs) || fieldsHasShape(params) || fieldsHasShape(results) {
t.SetHasShape(true)
}
return t
}
// NewStruct returns a new struct with the given fields.
func NewStruct(fields []*Field) *Type {
t := newType(TSTRUCT)
t.SetFields(fields)
if fieldsHasShape(fields) {
t.SetHasShape(true)
}
return t
}
var (
IsInt [NTYPE]bool
IsFloat [NTYPE]bool
IsComplex [NTYPE]bool
IsSimple [NTYPE]bool
)
var IsOrdered [NTYPE]bool
// IsReflexive reports whether t has a reflexive equality operator.
// That is, if x==x for all x of type t.
func IsReflexive(t *Type) bool {
switch t.Kind() {
case TBOOL,
TINT,
TUINT,
TINT8,
TUINT8,
TINT16,
TUINT16,
TINT32,
TUINT32,
TINT64,
TUINT64,
TUINTPTR,
TPTR,
TUNSAFEPTR,
TSTRING,
TCHAN:
return true
case TFLOAT32,
TFLOAT64,
TCOMPLEX64,
TCOMPLEX128,
TINTER:
return false
case TARRAY:
return IsReflexive(t.Elem())
case TSTRUCT:
for _, t1 := range t.Fields().Slice() {
if !IsReflexive(t1.Type) {
return false
}
}
return true
default:
base.Fatalf("bad type for map key: %v", t)
return false
}
}
// Can this type be stored directly in an interface word?
// Yes, if the representation is a single pointer.
func IsDirectIface(t *Type) bool {
switch t.Kind() {
case TPTR:
// Pointers to notinheap types must be stored indirectly. See issue 42076.
return !t.Elem().NotInHeap()
case TCHAN,
TMAP,
TFUNC,
TUNSAFEPTR:
return true
case TARRAY:
// Array of 1 direct iface type can be direct.
return t.NumElem() == 1 && IsDirectIface(t.Elem())
case TSTRUCT:
// Struct with 1 field of direct iface type can be direct.
return t.NumFields() == 1 && IsDirectIface(t.Field(0).Type)
}
return false
}
// IsInterfaceMethod reports whether (field) m is
// an interface method. Such methods have the
// special receiver type types.FakeRecvType().
func IsInterfaceMethod(f *Type) bool {
return f.Recv().Type == FakeRecvType()
}
// IsMethodApplicable reports whether method m can be called on a
// value of type t. This is necessary because we compute a single
// method set for both T and *T, but some *T methods are not
// applicable to T receivers.
func IsMethodApplicable(t *Type, m *Field) bool {
return t.IsPtr() || !m.Type.Recv().Type.IsPtr() || IsInterfaceMethod(m.Type) || m.Embedded == 2
}
// IsRuntimePkg reports whether p is package runtime.
func IsRuntimePkg(p *Pkg) bool {
if base.Flag.CompilingRuntime && p == LocalPkg {
return true
}
return p.Path == "runtime"
}
// IsReflectPkg reports whether p is package reflect.
func IsReflectPkg(p *Pkg) bool {
return p.Path == "reflect"
}
// IsTypePkg reports whether p is pesudo package type.
func IsTypePkg(p *Pkg) bool {
return p == typepkg
}
// IsNoInstrumentPkg reports whether p is a package that
// should not be instrumented.
func IsNoInstrumentPkg(p *Pkg) bool {
for _, np := range base.NoInstrumentPkgs {
if p.Path == np {
return true
}
}
return false
}
// IsNoRacePkg reports whether p is a package that
// should not be race instrumented.
func IsNoRacePkg(p *Pkg) bool {
for _, np := range base.NoRacePkgs {
if p.Path == np {
return true
}
}
return false
}
// ReceiverBaseType returns the underlying type, if any,
// that owns methods with receiver parameter t.
// The result is either a named type or an anonymous struct.
func ReceiverBaseType(t *Type) *Type {
if t == nil {
return nil
}
// Strip away pointer if it's there.
if t.IsPtr() {
if t.Sym() != nil {
return nil
}
t = t.Elem()
if t == nil {
return nil
}
}
// Must be a named type or anonymous struct.
if t.Sym() == nil && !t.IsStruct() {
return nil
}
// Check types.
if IsSimple[t.Kind()] {
return t
}
switch t.Kind() {
case TARRAY, TCHAN, TFUNC, TMAP, TSLICE, TSTRING, TSTRUCT:
return t
}
return nil
}
func FloatForComplex(t *Type) *Type {
switch t.Kind() {
case TCOMPLEX64:
return Types[TFLOAT32]
case TCOMPLEX128:
return Types[TFLOAT64]
}
base.Fatalf("unexpected type: %v", t)
return nil
}
func ComplexForFloat(t *Type) *Type {
switch t.Kind() {
case TFLOAT32:
return Types[TCOMPLEX64]
case TFLOAT64:
return Types[TCOMPLEX128]
}
base.Fatalf("unexpected type: %v", t)
return nil
}
func TypeSym(t *Type) *Sym {
return TypeSymLookup(TypeSymName(t))
}
func TypeSymLookup(name string) *Sym {
typepkgmu.Lock()
s := typepkg.Lookup(name)
typepkgmu.Unlock()
return s
}
func TypeSymName(t *Type) string {
name := t.LinkString()
// Use a separate symbol name for Noalg types for #17752.
if TypeHasNoAlg(t) {
name = "noalg." + name
}
return name
}
// Fake package for runtime type info (headers)
// Don't access directly, use typeLookup below.
var (
typepkgmu sync.Mutex // protects typepkg lookups
typepkg = NewPkg("type", "type")
)
var SimType [NTYPE]Kind
// Fake package for shape types (see typecheck.Shapify()).
var ShapePkg = NewPkg("go.shape", "go.shape")