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go / go / c7081409bb58edc0fcbccbba230b1667845e94a6 / . / src / cmd / compile / internal / gc / typecheck.go
blob: 314c3a91a6e2f30f01acf38301c884dd4f5e8219 [file] [log] [blame]
// Copyright 2009 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 gc
import (
"cmd/internal/obj"
"fmt"
"math"
"strings"
)
/*
* type check the whole tree of an expression.
* calculates expression types.
* evaluates compile time constants.
* marks variables that escape the local frame.
* rewrites n->op to be more specific in some cases.
*/
var typecheckdefstack *NodeList
/*
* resolve ONONAME to definition, if any.
*/
func resolve(n *Node) *Node {
if n != nil && n.Op == ONONAME && n.Sym != nil {
r := n.Sym.Def
if r != nil {
if r.Op != OIOTA {
n = r
} else if n.Name.Iota >= 0 {
n = Nodintconst(int64(n.Name.Iota))
}
}
}
return n
}
func typechecklist(l *NodeList, top int) {
for ; l != nil; l = l.Next {
typecheck(&l.N, top)
}
}
var _typekind = []string{
TINT: "int",
TUINT: "uint",
TINT8: "int8",
TUINT8: "uint8",
TINT16: "int16",
TUINT16: "uint16",
TINT32: "int32",
TUINT32: "uint32",
TINT64: "int64",
TUINT64: "uint64",
TUINTPTR: "uintptr",
TCOMPLEX64: "complex64",
TCOMPLEX128: "complex128",
TFLOAT32: "float32",
TFLOAT64: "float64",
TBOOL: "bool",
TSTRING: "string",
TPTR32: "pointer",
TPTR64: "pointer",
TUNSAFEPTR: "unsafe.Pointer",
TSTRUCT: "struct",
TINTER: "interface",
TCHAN: "chan",
TMAP: "map",
TARRAY: "array",
TFUNC: "func",
TNIL: "nil",
TIDEAL: "untyped number",
}
func typekind(t *Type) string {
if Isslice(t) {
return "slice"
}
et := int(t.Etype)
if 0 <= et && et < len(_typekind) {
s := _typekind[et]
if s != "" {
return s
}
}
return fmt.Sprintf("etype=%d", et)
}
// sprint_depchain prints a dependency chain of nodes into fmt.
// It is used by typecheck in the case of OLITERAL nodes
// to print constant definition loops.
func sprint_depchain(fmt_ *string, stack []*Node, cur *Node, first *Node) {
for i := len(stack) - 1; i >= 0; i-- {
if n := stack[i]; n.Op == cur.Op {
if n != first {
sprint_depchain(fmt_, stack[:i], n, first)
}
*fmt_ += fmt.Sprintf("\n\t%v: %v uses %v", n.Line(), n, cur)
return
}
}
}
var typecheck_tcstack []*Node
// typecheck type checks node *np.
// It replaces *np with a new pointer in some cases.
// It returns the final value of *np as a convenience.
func typecheck(np **Node, top int) *Node {
// cannot type check until all the source has been parsed
if !typecheckok {
Fatalf("early typecheck")
}
n := *np
if n == nil {
return nil
}
lno := int(setlineno(n))
// Skip over parens.
for n.Op == OPAREN {
n = n.Left
}
// Resolve definition of name and value of iota lazily.
n = resolve(n)
*np = n
// Skip typecheck if already done.
// But re-typecheck ONAME/OTYPE/OLITERAL/OPACK node in case context has changed.
if n.Typecheck == 1 {
switch n.Op {
case ONAME, OTYPE, OLITERAL, OPACK:
break
default:
lineno = int32(lno)
return n
}
}
if n.Typecheck == 2 {
// Typechecking loop. Trying printing a meaningful message,
// otherwise a stack trace of typechecking.
var fmt_ string
switch n.Op {
// We can already diagnose variables used as types.
case ONAME:
if top&(Erv|Etype) == Etype {
Yyerror("%v is not a type", n)
}
case OLITERAL:
if top&(Erv|Etype) == Etype {
Yyerror("%v is not a type", n)
break
}
sprint_depchain(&fmt_, typecheck_tcstack, n, n)
yyerrorl(int(n.Lineno), "constant definition loop%s", fmt_)
}
if nsavederrors+nerrors == 0 {
fmt_ = ""
for i := len(typecheck_tcstack) - 1; i >= 0; i-- {
x := typecheck_tcstack[i]
fmt_ += fmt.Sprintf("\n\t%v %v", x.Line(), x)
}
Yyerror("typechecking loop involving %v%s", n, fmt_)
}
lineno = int32(lno)
return n
}
n.Typecheck = 2
typecheck_tcstack = append(typecheck_tcstack, n)
typecheck1(&n, top)
*np = n
n.Typecheck = 1
last := len(typecheck_tcstack) - 1
typecheck_tcstack[last] = nil
typecheck_tcstack = typecheck_tcstack[:last]
lineno = int32(lno)
return n
}
/*
* does n contain a call or receive operation?
*/
func callrecv(n *Node) bool {
if n == nil {
return false
}
switch n.Op {
case OCALL,
OCALLMETH,
OCALLINTER,
OCALLFUNC,
ORECV,
OCAP,
OLEN,
OCOPY,
ONEW,
OAPPEND,
ODELETE:
return true
}
return callrecv(n.Left) || callrecv(n.Right) || callrecvlist(n.Ninit) || callrecvlist(n.Nbody) || callrecvlist(n.List) || callrecvlist(n.Rlist)
}
func callrecvlist(l *NodeList) bool {
for ; l != nil; l = l.Next {
if callrecv(l.N) {
return true
}
}
return false
}
// indexlit implements typechecking of untyped values as
// array/slice indexes. It is equivalent to defaultlit
// except for constants of numerical kind, which are acceptable
// whenever they can be represented by a value of type int.
func indexlit(np **Node) {
n := *np
if n == nil || !isideal(n.Type) {
return
}
switch consttype(n) {
case CTINT, CTRUNE, CTFLT, CTCPLX:
defaultlit(np, Types[TINT])
}
defaultlit(np, nil)
}
func typecheck1(np **Node, top int) {
n := *np
defer func() {
*np = n
}()
if n.Sym != nil {
if n.Op == ONAME && n.Etype != 0 && top&Ecall == 0 {
Yyerror("use of builtin %v not in function call", n.Sym)
n.Type = nil
return
}
typecheckdef(n)
if n.Op == ONONAME {
n.Type = nil
return
}
}
ok := 0
OpSwitch:
switch n.Op {
// until typecheck is complete, do nothing.
default:
Dump("typecheck", n)
Fatalf("typecheck %v", Oconv(int(n.Op), 0))
/*
* names
*/
case OLITERAL:
ok |= Erv
if n.Type == nil && n.Val().Ctype() == CTSTR {
n.Type = idealstring
}
break OpSwitch
case ONONAME:
ok |= Erv
break OpSwitch
case ONAME:
if n.Name.Decldepth == 0 {
n.Name.Decldepth = decldepth
}
if n.Etype != 0 {
ok |= Ecall
break OpSwitch
}
if top&Easgn == 0 {
// not a write to the variable
if isblank(n) {
Yyerror("cannot use _ as value")
n.Type = nil
return
}
n.Used = true
}
if top&Ecall == 0 && isunsafebuiltin(n) {
Yyerror("%v is not an expression, must be called", n)
n.Type = nil
return
}
ok |= Erv
break OpSwitch
case OPACK:
Yyerror("use of package %v without selector", n.Sym)
n.Type = nil
return
case ODDD:
break
/*
* types (OIND is with exprs)
*/
case OTYPE:
ok |= Etype
if n.Type == nil {
n.Type = nil
return
}
case OTARRAY:
ok |= Etype
t := typ(TARRAY)
l := n.Left
r := n.Right
if l == nil {
t.Bound = -1 // slice
} else if l.Op == ODDD {
t.Bound = -100 // to be filled in
if top&Ecomplit == 0 && n.Diag == 0 {
t.Broke = true
n.Diag = 1
Yyerror("use of [...] array outside of array literal")
}
} else {
l := typecheck(&n.Left, Erv)
var v Val
switch consttype(l) {
case CTINT, CTRUNE:
v = l.Val()
case CTFLT:
v = toint(l.Val())
default:
if l.Type != nil && Isint[l.Type.Etype] && l.Op != OLITERAL {
Yyerror("non-constant array bound %v", l)
} else {
Yyerror("invalid array bound %v", l)
}
n.Type = nil
return
}
t.Bound = Mpgetfix(v.U.(*Mpint))
if doesoverflow(v, Types[TINT]) {
Yyerror("array bound is too large")
n.Type = nil
return
} else if t.Bound < 0 {
Yyerror("array bound must be non-negative")
n.Type = nil
return
}
}
typecheck(&r, Etype)
if r.Type == nil {
n.Type = nil
return
}
t.Type = r.Type
n.Op = OTYPE
n.Type = t
n.Left = nil
n.Right = nil
if t.Bound != -100 {
checkwidth(t)
}
case OTMAP:
ok |= Etype
l := typecheck(&n.Left, Etype)
r := typecheck(&n.Right, Etype)
if l.Type == nil || r.Type == nil {
n.Type = nil
return
}
n.Op = OTYPE
n.Type = maptype(l.Type, r.Type)
n.Left = nil
n.Right = nil
case OTCHAN:
ok |= Etype
l := typecheck(&n.Left, Etype)
if l.Type == nil {
n.Type = nil
return
}
t := typ(TCHAN)
t.Type = l.Type
t.Chan = n.Etype
n.Op = OTYPE
n.Type = t
n.Left = nil
n.Etype = 0
case OTSTRUCT:
ok |= Etype
n.Op = OTYPE
n.Type = tostruct(n.List)
if n.Type == nil || n.Type.Broke {
n.Type = nil
return
}
n.List = nil
case OTINTER:
ok |= Etype
n.Op = OTYPE
n.Type = tointerface(n.List)
if n.Type == nil {
n.Type = nil
return
}
case OTFUNC:
ok |= Etype
n.Op = OTYPE
n.Type = functype(n.Left, n.List, n.Rlist)
if n.Type == nil {
n.Type = nil
return
}
/*
* type or expr
*/
case OIND:
ntop := Erv | Etype
if top&Eaddr == 0 { // The *x in &*x is not an indirect.
ntop |= Eindir
}
ntop |= top & Ecomplit
l := typecheck(&n.Left, ntop)
t := l.Type
if t == nil {
n.Type = nil
return
}
if l.Op == OTYPE {
ok |= Etype
n.Op = OTYPE
n.Type = Ptrto(l.Type)
n.Left = nil
break OpSwitch
}
if !Isptr[t.Etype] {
if top&(Erv|Etop) != 0 {
Yyerror("invalid indirect of %v", Nconv(n.Left, obj.FmtLong))
n.Type = nil
return
}
break OpSwitch
}
ok |= Erv
n.Type = t.Type
break OpSwitch
/*
* arithmetic exprs
*/
case OASOP,
OADD,
OAND,
OANDAND,
OANDNOT,
ODIV,
OEQ,
OGE,
OGT,
OHMUL,
OLE,
OLT,
OLSH,
ORSH,
OMOD,
OMUL,
ONE,
OOR,
OOROR,
OSUB,
OXOR:
var l *Node
var op int
var r *Node
if n.Op == OASOP {
ok |= Etop
l = typecheck(&n.Left, Erv)
r = typecheck(&n.Right, Erv)
checkassign(n, n.Left)
if l.Type == nil || r.Type == nil {
n.Type = nil
return
}
op = int(n.Etype)
} else {
ok |= Erv
l = typecheck(&n.Left, Erv|top&Eiota)
r = typecheck(&n.Right, Erv|top&Eiota)
if l.Type == nil || r.Type == nil {
n.Type = nil
return
}
op = int(n.Op)
}
if op == OLSH || op == ORSH {
defaultlit(&r, Types[TUINT])
n.Right = r
t := r.Type
if !Isint[t.Etype] || Issigned[t.Etype] {
Yyerror("invalid operation: %v (shift count type %v, must be unsigned integer)", n, r.Type)
n.Type = nil
return
}
t = l.Type
if t != nil && t.Etype != TIDEAL && !Isint[t.Etype] {
Yyerror("invalid operation: %v (shift of type %v)", n, t)
n.Type = nil
return
}
// no defaultlit for left
// the outer context gives the type
n.Type = l.Type
break OpSwitch
}
// ideal mixed with non-ideal
defaultlit2(&l, &r, 0)
n.Left = l
n.Right = r
if l.Type == nil || r.Type == nil {
n.Type = nil
return
}
t := l.Type
if t.Etype == TIDEAL {
t = r.Type
}
et := int(t.Etype)
if et == TIDEAL {
et = TINT
}
aop := 0
if iscmp[n.Op] && t.Etype != TIDEAL && !Eqtype(l.Type, r.Type) {
// comparison is okay as long as one side is
// assignable to the other. convert so they have
// the same type.
//
// the only conversion that isn't a no-op is concrete == interface.
// in that case, check comparability of the concrete type.
// The conversion allocates, so only do it if the concrete type is huge.
if r.Type.Etype != TBLANK {
aop = assignop(l.Type, r.Type, nil)
if aop != 0 {
if Isinter(r.Type) && !Isinter(l.Type) && algtype1(l.Type, nil) == ANOEQ {
Yyerror("invalid operation: %v (operator %v not defined on %s)", n, Oconv(int(op), 0), typekind(l.Type))
n.Type = nil
return
}
dowidth(l.Type)
if Isinter(r.Type) == Isinter(l.Type) || l.Type.Width >= 1<<16 {
l = Nod(aop, l, nil)
l.Type = r.Type
l.Typecheck = 1
n.Left = l
}
t = r.Type
goto converted
}
}
if l.Type.Etype != TBLANK {
aop = assignop(r.Type, l.Type, nil)
if aop != 0 {
if Isinter(l.Type) && !Isinter(r.Type) && algtype1(r.Type, nil) == ANOEQ {
Yyerror("invalid operation: %v (operator %v not defined on %s)", n, Oconv(int(op), 0), typekind(r.Type))
n.Type = nil
return
}
dowidth(r.Type)
if Isinter(r.Type) == Isinter(l.Type) || r.Type.Width >= 1<<16 {
r = Nod(aop, r, nil)
r.Type = l.Type
r.Typecheck = 1
n.Right = r
}
t = l.Type
}
}
converted:
et = int(t.Etype)
}
if t.Etype != TIDEAL && !Eqtype(l.Type, r.Type) {
defaultlit2(&l, &r, 1)
if n.Op == OASOP && n.Implicit {
Yyerror("invalid operation: %v (non-numeric type %v)", n, l.Type)
n.Type = nil
return
}
if Isinter(r.Type) == Isinter(l.Type) || aop == 0 {
Yyerror("invalid operation: %v (mismatched types %v and %v)", n, l.Type, r.Type)
n.Type = nil
return
}
}
if !okfor[op][et] {
Yyerror("invalid operation: %v (operator %v not defined on %s)", n, Oconv(int(op), 0), typekind(t))
n.Type = nil
return
}
// okfor allows any array == array, map == map, func == func.
// restrict to slice/map/func == nil and nil == slice/map/func.
if Isfixedarray(l.Type) && algtype1(l.Type, nil) == ANOEQ {
Yyerror("invalid operation: %v (%v cannot be compared)", n, l.Type)
n.Type = nil
return
}
if Isslice(l.Type) && !isnil(l) && !isnil(r) {
Yyerror("invalid operation: %v (slice can only be compared to nil)", n)
n.Type = nil
return
}
if l.Type.Etype == TMAP && !isnil(l) && !isnil(r) {
Yyerror("invalid operation: %v (map can only be compared to nil)", n)
n.Type = nil
return
}
if l.Type.Etype == TFUNC && !isnil(l) && !isnil(r) {
Yyerror("invalid operation: %v (func can only be compared to nil)", n)
n.Type = nil
return
}
var badtype *Type
if l.Type.Etype == TSTRUCT && algtype1(l.Type, &badtype) == ANOEQ {
Yyerror("invalid operation: %v (struct containing %v cannot be compared)", n, badtype)
n.Type = nil
return
}
t = l.Type
if iscmp[n.Op] {
evconst(n)
t = idealbool
if n.Op != OLITERAL {
defaultlit2(&l, &r, 1)
n.Left = l
n.Right = r
}
} else if n.Op == OANDAND || n.Op == OOROR {
if l.Type == r.Type {
t = l.Type
} else if l.Type == idealbool {
t = r.Type
} else if r.Type == idealbool {
t = l.Type
}
} else
// non-comparison operators on ideal bools should make them lose their ideal-ness
if t == idealbool {
t = Types[TBOOL]
}
if et == TSTRING {
if iscmp[n.Op] {
n.Etype = n.Op
n.Op = OCMPSTR
} else if n.Op == OADD {
// create OADDSTR node with list of strings in x + y + z + (w + v) + ...
n.Op = OADDSTR
if l.Op == OADDSTR {
n.List = l.List
} else {
n.List = list1(l)
}
if r.Op == OADDSTR {
n.List = concat(n.List, r.List)
} else {
n.List = list(n.List, r)
}
n.Left = nil
n.Right = nil
}
}
if et == TINTER {
if l.Op == OLITERAL && l.Val().Ctype() == CTNIL {
// swap for back end
n.Left = r
n.Right = l
} else if r.Op == OLITERAL && r.Val().Ctype() == CTNIL {
} else // leave alone for back end
if Isinter(r.Type) == Isinter(l.Type) {
n.Etype = n.Op
n.Op = OCMPIFACE
}
}
if (op == ODIV || op == OMOD) && Isconst(r, CTINT) {
if mpcmpfixc(r.Val().U.(*Mpint), 0) == 0 {
Yyerror("division by zero")
n.Type = nil
return
}
}
n.Type = t
break OpSwitch
case OCOM, OMINUS, ONOT, OPLUS:
ok |= Erv
l := typecheck(&n.Left, Erv|top&Eiota)
t := l.Type
if t == nil {
n.Type = nil
return
}
if !okfor[n.Op][t.Etype] {
Yyerror("invalid operation: %v %v", Oconv(int(n.Op), 0), t)
n.Type = nil
return
}
n.Type = t
break OpSwitch
/*
* exprs
*/
case OADDR:
ok |= Erv
typecheck(&n.Left, Erv|Eaddr)
if n.Left.Type == nil {
n.Type = nil
return
}
checklvalue(n.Left, "take the address of")
r := outervalue(n.Left)
var l *Node
for l = n.Left; l != r; l = l.Left {
l.Addrtaken = true
if l.Name != nil && l.Name.Param != nil && l.Name.Param.Closure != nil {
l.Name.Param.Closure.Addrtaken = true
}
}
if l.Orig != l && l.Op == ONAME {
Fatalf("found non-orig name node %v", l)
}
l.Addrtaken = true
if l.Name != nil && l.Name.Param != nil && l.Name.Param.Closure != nil {
l.Name.Param.Closure.Addrtaken = true
}
defaultlit(&n.Left, nil)
l = n.Left
t := l.Type
if t == nil {
n.Type = nil
return
}
n.Type = Ptrto(t)
break OpSwitch
case OCOMPLIT:
ok |= Erv
typecheckcomplit(&n)
if n.Type == nil {
n.Type = nil
return
}
break OpSwitch
case OXDOT, ODOT:
if n.Op == OXDOT {
n = adddot(n)
n.Op = ODOT
if n.Left == nil {
n.Type = nil
return
}
}
typecheck(&n.Left, Erv|Etype)
defaultlit(&n.Left, nil)
if n.Right.Op != ONAME {
Yyerror("rhs of . must be a name") // impossible
n.Type = nil
return
}
t := n.Left.Type
if t == nil {
adderrorname(n)
n.Type = nil
return
}
r := n.Right
if n.Left.Op == OTYPE {
if !looktypedot(n, t, 0) {
if looktypedot(n, t, 1) {
Yyerror("%v undefined (cannot refer to unexported method %v)", n, n.Right.Sym)
} else {
Yyerror("%v undefined (type %v has no method %v)", n, t, n.Right.Sym)
}
n.Type = nil
return
}
if n.Type.Etype != TFUNC || n.Type.Thistuple != 1 {
Yyerror("type %v has no method %v", n.Left.Type, Sconv(n.Right.Sym, obj.FmtShort))
n.Type = nil
n.Type = nil
return
}
n.Op = ONAME
if n.Name == nil {
n.Name = new(Name)
}
n.Sym = n.Right.Sym
n.Type = methodfunc(n.Type, n.Left.Type)
n.Xoffset = 0
n.Class = PFUNC
ok = Erv
break OpSwitch
}
if Isptr[t.Etype] && t.Type.Etype != TINTER {
t = t.Type
if t == nil {
n.Type = nil
return
}
n.Op = ODOTPTR
checkwidth(t)
}
if isblank(n.Right) {
Yyerror("cannot refer to blank field or method")
n.Type = nil
return
}
if lookdot(n, t, 0) == nil {
// Legitimate field or method lookup failed, try to explain the error
switch {
case isnilinter(t):
Yyerror("%v undefined (type %v is interface with no methods)", n, n.Left.Type)
case Isptr[t.Etype] && Isinter(t.Type):
// Pointer to interface is almost always a mistake.
Yyerror("%v undefined (type %v is pointer to interface, not interface)", n, n.Left.Type)
case lookdot(n, t, 1) != nil:
// Field or method matches by name, but it is not exported.
Yyerror("%v undefined (cannot refer to unexported field or method %v)", n, n.Right.Sym)
default:
if mt := lookdot(n, t, 2); mt != nil { // Case-insensitive lookup.
Yyerror("%v undefined (type %v has no field or method %v, but does have %v)", n, n.Left.Type, n.Right.Sym, mt.Sym)
} else {
Yyerror("%v undefined (type %v has no field or method %v)", n, n.Left.Type, n.Right.Sym)
}
}
n.Type = nil
return
}
switch n.Op {
case ODOTINTER, ODOTMETH:
if top&Ecall != 0 {
ok |= Ecall
} else {
typecheckpartialcall(n, r)
ok |= Erv
}
default:
ok |= Erv
}
break OpSwitch
case ODOTTYPE:
ok |= Erv
typecheck(&n.Left, Erv)
defaultlit(&n.Left, nil)
l := n.Left
t := l.Type
if t == nil {
n.Type = nil
return
}
if !Isinter(t) {
Yyerror("invalid type assertion: %v (non-interface type %v on left)", n, t)
n.Type = nil
return
}
if n.Right != nil {
typecheck(&n.Right, Etype)
n.Type = n.Right.Type
n.Right = nil
if n.Type == nil {
n.Type = nil
return
}
}
if n.Type != nil && n.Type.Etype != TINTER {
var have *Type
var missing *Type
var ptr int
if !implements(n.Type, t, &missing, &have, &ptr) {
if have != nil && have.Sym == missing.Sym {
Yyerror("impossible type assertion:\n\t%v does not implement %v (wrong type for %v method)\n"+"\t\thave %v%v\n\t\twant %v%v", n.Type, t, missing.Sym, have.Sym, Tconv(have.Type, obj.FmtShort|obj.FmtByte), missing.Sym, Tconv(missing.Type, obj.FmtShort|obj.FmtByte))
} else if ptr != 0 {
Yyerror("impossible type assertion:\n\t%v does not implement %v (%v method has pointer receiver)", n.Type, t, missing.Sym)
} else if have != nil {
Yyerror("impossible type assertion:\n\t%v does not implement %v (missing %v method)\n"+"\t\thave %v%v\n\t\twant %v%v", n.Type, t, missing.Sym, have.Sym, Tconv(have.Type, obj.FmtShort|obj.FmtByte), missing.Sym, Tconv(missing.Type, obj.FmtShort|obj.FmtByte))
} else {
Yyerror("impossible type assertion:\n\t%v does not implement %v (missing %v method)", n.Type, t, missing.Sym)
}
n.Type = nil
return
}
}
break OpSwitch
case OINDEX:
ok |= Erv
typecheck(&n.Left, Erv)
defaultlit(&n.Left, nil)
implicitstar(&n.Left)
l := n.Left
typecheck(&n.Right, Erv)
r := n.Right
t := l.Type
if t == nil || r.Type == nil {
n.Type = nil
return
}
switch t.Etype {
default:
Yyerror("invalid operation: %v (type %v does not support indexing)", n, t)
n.Type = nil
return
case TSTRING, TARRAY:
indexlit(&n.Right)
if t.Etype == TSTRING {
n.Type = bytetype
} else {
n.Type = t.Type
}
why := "string"
if t.Etype == TARRAY {
if Isfixedarray(t) {
why = "array"
} else {
why = "slice"
}
}
if n.Right.Type != nil && !Isint[n.Right.Type.Etype] {
Yyerror("non-integer %s index %v", why, n.Right)
break
}
if Isconst(n.Right, CTINT) {
x := Mpgetfix(n.Right.Val().U.(*Mpint))
if x < 0 {
Yyerror("invalid %s index %v (index must be non-negative)", why, n.Right)
} else if Isfixedarray(t) && t.Bound > 0 && x >= t.Bound {
Yyerror("invalid array index %v (out of bounds for %d-element array)", n.Right, t.Bound)
} else if Isconst(n.Left, CTSTR) && x >= int64(len(n.Left.Val().U.(string))) {
Yyerror("invalid string index %v (out of bounds for %d-byte string)", n.Right, len(n.Left.Val().U.(string)))
} else if Mpcmpfixfix(n.Right.Val().U.(*Mpint), Maxintval[TINT]) > 0 {
Yyerror("invalid %s index %v (index too large)", why, n.Right)
}
}
case TMAP:
n.Etype = 0
defaultlit(&n.Right, t.Down)
if n.Right.Type != nil {
n.Right = assignconv(n.Right, t.Down, "map index")
}
n.Type = t.Type
n.Op = OINDEXMAP
}
break OpSwitch
case ORECV:
ok |= Etop | Erv
typecheck(&n.Left, Erv)
defaultlit(&n.Left, nil)
l := n.Left
t := l.Type
if t == nil {
n.Type = nil
return
}
if t.Etype != TCHAN {
Yyerror("invalid operation: %v (receive from non-chan type %v)", n, t)
n.Type = nil
return
}
if t.Chan&Crecv == 0 {
Yyerror("invalid operation: %v (receive from send-only type %v)", n, t)
n.Type = nil
return
}
n.Type = t.Type
break OpSwitch
case OSEND:
ok |= Etop
l := typecheck(&n.Left, Erv)
typecheck(&n.Right, Erv)
defaultlit(&n.Left, nil)
l = n.Left
t := l.Type
if t == nil {
n.Type = nil
return
}
if t.Etype != TCHAN {
Yyerror("invalid operation: %v (send to non-chan type %v)", n, t)
n.Type = nil
return
}
if t.Chan&Csend == 0 {
Yyerror("invalid operation: %v (send to receive-only type %v)", n, t)
n.Type = nil
return
}
defaultlit(&n.Right, t.Type)
r := n.Right
if r.Type == nil {
n.Type = nil
return
}
n.Right = assignconv(r, l.Type.Type, "send")
// TODO: more aggressive
n.Etype = 0
n.Type = nil
break OpSwitch
case OSLICE:
ok |= Erv
typecheck(&n.Left, top)
typecheck(&n.Right.Left, Erv)
typecheck(&n.Right.Right, Erv)
defaultlit(&n.Left, nil)
indexlit(&n.Right.Left)
indexlit(&n.Right.Right)
l := n.Left
if Isfixedarray(l.Type) {
if !islvalue(n.Left) {
Yyerror("invalid operation %v (slice of unaddressable value)", n)
n.Type = nil
return
}
n.Left = Nod(OADDR, n.Left, nil)
n.Left.Implicit = true
typecheck(&n.Left, Erv)
l = n.Left
}
t := l.Type
if t == nil {
n.Type = nil
return
}
var tp *Type
if Istype(t, TSTRING) {
n.Type = t
n.Op = OSLICESTR
} else if Isptr[t.Etype] && Isfixedarray(t.Type) {
tp = t.Type
n.Type = typ(TARRAY)
n.Type.Type = tp.Type
n.Type.Bound = -1
dowidth(n.Type)
n.Op = OSLICEARR
} else if Isslice(t) {
n.Type = t
} else {
Yyerror("cannot slice %v (type %v)", l, t)
n.Type = nil
return
}
lo := n.Right.Left
if lo != nil && checksliceindex(l, lo, tp) < 0 {
n.Type = nil
return
}
hi := n.Right.Right
if hi != nil && checksliceindex(l, hi, tp) < 0 {
n.Type = nil
return
}
if checksliceconst(lo, hi) < 0 {
n.Type = nil
return
}
break OpSwitch
case OSLICE3:
ok |= Erv
typecheck(&n.Left, top)
typecheck(&n.Right.Left, Erv)
typecheck(&n.Right.Right.Left, Erv)
typecheck(&n.Right.Right.Right, Erv)
defaultlit(&n.Left, nil)
indexlit(&n.Right.Left)
indexlit(&n.Right.Right.Left)
indexlit(&n.Right.Right.Right)
l := n.Left
if Isfixedarray(l.Type) {
if !islvalue(n.Left) {
Yyerror("invalid operation %v (slice of unaddressable value)", n)
n.Type = nil
return
}
n.Left = Nod(OADDR, n.Left, nil)
n.Left.Implicit = true
typecheck(&n.Left, Erv)
l = n.Left
}
t := l.Type
if t == nil {
n.Type = nil
return
}
if Istype(t, TSTRING) {
Yyerror("invalid operation %v (3-index slice of string)", n)
n.Type = nil
return
}
var tp *Type
if Isptr[t.Etype] && Isfixedarray(t.Type) {
tp = t.Type
n.Type = typ(TARRAY)
n.Type.Type = tp.Type
n.Type.Bound = -1
dowidth(n.Type)
n.Op = OSLICE3ARR
} else if Isslice(t) {
n.Type = t
} else {
Yyerror("cannot slice %v (type %v)", l, t)
n.Type = nil
return
}
lo := n.Right.Left
if lo != nil && checksliceindex(l, lo, tp) < 0 {
n.Type = nil
return
}
mid := n.Right.Right.Left
if mid != nil && checksliceindex(l, mid, tp) < 0 {
n.Type = nil
return
}
hi := n.Right.Right.Right
if hi != nil && checksliceindex(l, hi, tp) < 0 {
n.Type = nil
return
}
if checksliceconst(lo, hi) < 0 || checksliceconst(lo, mid) < 0 || checksliceconst(mid, hi) < 0 {
n.Type = nil
return
}
break OpSwitch
/*
* call and call like
*/
case OCALL:
l := n.Left
if l.Op == ONAME {
r := unsafenmagic(n)
if r != nil {
if n.Isddd {
Yyerror("invalid use of ... with builtin %v", l)
}
n = r
typecheck1(&n, top)
return
}
}
typecheck(&n.Left, Erv|Etype|Ecall|top&Eproc)
n.Diag |= n.Left.Diag
l = n.Left
if l.Op == ONAME && l.Etype != 0 {
if n.Isddd && l.Etype != OAPPEND {
Yyerror("invalid use of ... with builtin %v", l)
}
// builtin: OLEN, OCAP, etc.
n.Op = l.Etype
n.Left = n.Right
n.Right = nil
typecheck1(&n, top)
return
}
defaultlit(&n.Left, nil)
l = n.Left
if l.Op == OTYPE {
if n.Isddd || l.Type.Bound == -100 {
if !l.Type.Broke {
Yyerror("invalid use of ... in type conversion to %v", l.Type)
}
n.Diag = 1
}
// pick off before type-checking arguments
ok |= Erv
// turn CALL(type, arg) into CONV(arg) w/ type
n.Left = nil
n.Op = OCONV
n.Type = l.Type
if onearg(n, "conversion to %v", l.Type) < 0 {
n.Type = nil
return
}
typecheck1(&n, top)
return
}
if count(n.List) == 1 && !n.Isddd {
typecheck(&n.List.N, Erv|Efnstruct)
} else {
typechecklist(n.List, Erv)
}
t := l.Type
if t == nil {
n.Type = nil
return
}
checkwidth(t)
switch l.Op {
case ODOTINTER:
n.Op = OCALLINTER
case ODOTMETH:
n.Op = OCALLMETH
// typecheckaste was used here but there wasn't enough
// information further down the call chain to know if we
// were testing a method receiver for unexported fields.
// It isn't necessary, so just do a sanity check.
tp := getthisx(t).Type.Type
if l.Left == nil || !Eqtype(l.Left.Type, tp) {
Fatalf("method receiver")
}
default:
n.Op = OCALLFUNC
if t.Etype != TFUNC {
Yyerror("cannot call non-function %v (type %v)", l, t)
n.Type = nil
return
}
}
typecheckaste(OCALL, n.Left, n.Isddd, getinargx(t), n.List, func() string { return fmt.Sprintf("argument to %v", n.Left) })
ok |= Etop
if t.Outtuple == 0 {
break OpSwitch
}
ok |= Erv
if t.Outtuple == 1 {
t := getoutargx(l.Type).Type
if t == nil {
n.Type = nil
return
}
if t.Etype == TFIELD {
t = t.Type
}
n.Type = t
if n.Op == OCALLFUNC && n.Left.Op == ONAME && (compiling_runtime != 0 || n.Left.Sym.Pkg == Runtimepkg) && n.Left.Sym.Name == "getg" {
// Emit code for runtime.getg() directly instead of calling function.
// Most such rewrites (for example the similar one for math.Sqrt) should be done in walk,
// so that the ordering pass can make sure to preserve the semantics of the original code
// (in particular, the exact time of the function call) by introducing temporaries.
// In this case, we know getg() always returns the same result within a given function
// and we want to avoid the temporaries, so we do the rewrite earlier than is typical.
n.Op = OGETG
}
break OpSwitch
}
// multiple return
if top&(Efnstruct|Etop) == 0 {
Yyerror("multiple-value %v() in single-value context", l)
break OpSwitch
}
n.Type = getoutargx(l.Type)
break OpSwitch
case OCAP, OLEN, OREAL, OIMAG:
ok |= Erv
if onearg(n, "%v", Oconv(int(n.Op), 0)) < 0 {
n.Type = nil
return
}
typecheck(&n.Left, Erv)
defaultlit(&n.Left, nil)
implicitstar(&n.Left)
l := n.Left
t := l.Type
if t == nil {
n.Type = nil
return
}
switch n.Op {
case OCAP:
if !okforcap[t.Etype] {
goto badcall1
}
case OLEN:
if !okforlen[t.Etype] {
goto badcall1
}
case OREAL, OIMAG:
if !Iscomplex[t.Etype] {
goto badcall1
}
if Isconst(l, CTCPLX) {
r := n
if n.Op == OREAL {
n = nodfltconst(&l.Val().U.(*Mpcplx).Real)
} else {
n = nodfltconst(&l.Val().U.(*Mpcplx).Imag)
}
n.Orig = r
}
n.Type = Types[cplxsubtype(int(t.Etype))]
break OpSwitch
}
// might be constant
switch t.Etype {
case TSTRING:
if Isconst(l, CTSTR) {
r := Nod(OXXX, nil, nil)
Nodconst(r, Types[TINT], int64(len(l.Val().U.(string))))
r.Orig = n
n = r
}
case TARRAY:
if t.Bound < 0 { // slice
break
}
if callrecv(l) { // has call or receive
break
}
r := Nod(OXXX, nil, nil)
Nodconst(r, Types[TINT], t.Bound)
r.Orig = n
n = r
}
n.Type = Types[TINT]
break OpSwitch
badcall1:
Yyerror("invalid argument %v for %v", Nconv(n.Left, obj.FmtLong), Oconv(int(n.Op), 0))
n.Type = nil
return
case OCOMPLEX:
ok |= Erv
var r *Node
var l *Node
if count(n.List) == 1 {
typechecklist(n.List, Efnstruct)
if n.List.N.Op != OCALLFUNC && n.List.N.Op != OCALLMETH {
Yyerror("invalid operation: complex expects two arguments")
n.Type = nil
return
}
t := n.List.N.Left.Type
if t.Outtuple != 2 {
Yyerror("invalid operation: complex expects two arguments, %v returns %d results", n.List.N, t.Outtuple)
n.Type = nil
return
}
t = n.List.N.Type.Type
l = t.Nname
r = t.Down.Nname
} else {
if twoarg(n) < 0 {
n.Type = nil
return
}
l = typecheck(&n.Left, Erv|top&Eiota)
r = typecheck(&n.Right, Erv|top&Eiota)
if l.Type == nil || r.Type == nil {
n.Type = nil
return
}
defaultlit2(&l, &r, 0)
if l.Type == nil || r.Type == nil {
n.Type = nil
return
}
n.Left = l
n.Right = r
}
if !Eqtype(l.Type, r.Type) {
Yyerror("invalid operation: %v (mismatched types %v and %v)", n, l.Type, r.Type)
n.Type = nil
return
}
var t *Type
switch l.Type.Etype {
default:
Yyerror("invalid operation: %v (arguments have type %v, expected floating-point)", n, l.Type)
n.Type = nil
return
case TIDEAL:
t = Types[TIDEAL]
case TFLOAT32:
t = Types[TCOMPLEX64]
case TFLOAT64:
t = Types[TCOMPLEX128]
}
if l.Op == OLITERAL && r.Op == OLITERAL {
// make it a complex literal
r = nodcplxlit(l.Val(), r.Val())
r.Orig = n
n = r
}
n.Type = t
break OpSwitch
case OCLOSE:
if onearg(n, "%v", Oconv(int(n.Op), 0)) < 0 {
n.Type = nil
return
}
typecheck(&n.Left, Erv)
defaultlit(&n.Left, nil)
l := n.Left
t := l.Type
if t == nil {
n.Type = nil
return
}
if t.Etype != TCHAN {
Yyerror("invalid operation: %v (non-chan type %v)", n, t)
n.Type = nil
return
}
if t.Chan&Csend == 0 {
Yyerror("invalid operation: %v (cannot close receive-only channel)", n)
n.Type = nil
return
}
ok |= Etop
break OpSwitch
case ODELETE:
args := n.List
if args == nil {
Yyerror("missing arguments to delete")
n.Type = nil
return
}
if args.Next == nil {
Yyerror("missing second (key) argument to delete")
n.Type = nil
return
}
if args.Next.Next != nil {
Yyerror("too many arguments to delete")
n.Type = nil
return
}
ok |= Etop
typechecklist(args, Erv)
l := args.N
r := args.Next.N
if l.Type != nil && l.Type.Etype != TMAP {
Yyerror("first argument to delete must be map; have %v", Tconv(l.Type, obj.FmtLong))
n.Type = nil
return
}
args.Next.N = assignconv(r, l.Type.Down, "delete")
break OpSwitch
case OAPPEND:
ok |= Erv
args := n.List
if args == nil {
Yyerror("missing arguments to append")
n.Type = nil
return
}
if count(args) == 1 && !n.Isddd {
typecheck(&args.N, Erv|Efnstruct)
} else {
typechecklist(args, Erv)
}
t := args.N.Type
if t == nil {
n.Type = nil
return
}
// Unpack multiple-return result before type-checking.
var funarg *Type
if Istype(t, TSTRUCT) && t.Funarg {
funarg = t
t = t.Type.Type
}
n.Type = t
if !Isslice(t) {
if Isconst(args.N, CTNIL) {
Yyerror("first argument to append must be typed slice; have untyped nil")
n.Type = nil
return
}
Yyerror("first argument to append must be slice; have %v", Tconv(t, obj.FmtLong))
n.Type = nil
return
}
if n.Isddd {
if args.Next == nil {
Yyerror("cannot use ... on first argument to append")
n.Type = nil
return
}
if args.Next.Next != nil {
Yyerror("too many arguments to append")
n.Type = nil
return
}
if Istype(t.Type, TUINT8) && Istype(args.Next.N.Type, TSTRING) {
defaultlit(&args.Next.N, Types[TSTRING])
break OpSwitch
}
args.Next.N = assignconv(args.Next.N, t.Orig, "append")
break OpSwitch
}
if funarg != nil {
for t := funarg.Type.Down; t != nil; t = t.Down {
if assignop(t.Type, n.Type.Type, nil) == 0 {
Yyerror("cannot append %v value to []%v", t.Type, n.Type.Type)
}
}
} else {
for args = args.Next; args != nil; args = args.Next {
if args.N.Type == nil {
continue
}
args.N = assignconv(args.N, t.Type, "append")
}
}
break OpSwitch
case OCOPY:
ok |= Etop | Erv
args := n.List
if args == nil || args.Next == nil {
Yyerror("missing arguments to copy")
n.Type = nil
return
}
if args.Next.Next != nil {
Yyerror("too many arguments to copy")
n.Type = nil
return
}
n.Left = args.N
n.Right = args.Next.N
n.List = nil
n.Type = Types[TINT]
typecheck(&n.Left, Erv)
typecheck(&n.Right, Erv)
if n.Left.Type == nil || n.Right.Type == nil {
n.Type = nil
return
}
defaultlit(&n.Left, nil)
defaultlit(&n.Right, nil)
if n.Left.Type == nil || n.Right.Type == nil {
n.Type = nil
return
}
// copy([]byte, string)
if Isslice(n.Left.Type) && n.Right.Type.Etype == TSTRING {
if Eqtype(n.Left.Type.Type, bytetype) {
break OpSwitch
}
Yyerror("arguments to copy have different element types: %v and string", Tconv(n.Left.Type, obj.FmtLong))
n.Type = nil
return
}
if !Isslice(n.Left.Type) || !Isslice(n.Right.Type) {
if !Isslice(n.Left.Type) && !Isslice(n.Right.Type) {
Yyerror("arguments to copy must be slices; have %v, %v", Tconv(n.Left.Type, obj.FmtLong), Tconv(n.Right.Type, obj.FmtLong))
} else if !Isslice(n.Left.Type) {
Yyerror("first argument to copy should be slice; have %v", Tconv(n.Left.Type, obj.FmtLong))
} else {
Yyerror("second argument to copy should be slice or string; have %v", Tconv(n.Right.Type, obj.FmtLong))
}
n.Type = nil
return
}
if !Eqtype(n.Left.Type.Type, n.Right.Type.Type) {
Yyerror("arguments to copy have different element types: %v and %v", Tconv(n.Left.Type, obj.FmtLong), Tconv(n.Right.Type, obj.FmtLong))
n.Type = nil
return
}
break OpSwitch
case OCONV:
ok |= Erv
saveorignode(n)
typecheck(&n.Left, Erv|top&(Eindir|Eiota))
convlit1(&n.Left, n.Type, true)
t := n.Left.Type
if t == nil || n.Type == nil {
n.Type = nil
return
}
var why string
n.Op = uint8(convertop(t, n.Type, &why))
if (n.Op) == 0 {
if n.Diag == 0 && !n.Type.Broke {
Yyerror("cannot convert %v to type %v%s", Nconv(n.Left, obj.FmtLong), n.Type, why)
n.Diag = 1
}
n.Op = OCONV
}
switch n.Op {
case OCONVNOP:
if n.Left.Op == OLITERAL && n.Type != Types[TBOOL] {
r := Nod(OXXX, nil, nil)
n.Op = OCONV
n.Orig = r
*r = *n
n.Op = OLITERAL
n.SetVal(n.Left.Val())
}
// do not use stringtoarraylit.
// generated code and compiler memory footprint is better without it.
case OSTRARRAYBYTE:
break
case OSTRARRAYRUNE:
if n.Left.Op == OLITERAL {
stringtoarraylit(&n)
}
}
break OpSwitch
case OMAKE:
ok |= Erv
args := n.List
if args == nil {
Yyerror("missing argument to make")
n.Type = nil
return
}
n.List = nil
l := args.N
args = args.Next
typecheck(&l, Etype)
t := l.Type
if t == nil {
n.Type = nil
return
}
switch t.Etype {
default:
Yyerror("cannot make type %v", t)
n.Type = nil
return
case TARRAY:
if !Isslice(t) {
Yyerror("cannot make type %v", t)
n.Type = nil
return
}
if args == nil {
Yyerror("missing len argument to make(%v)", t)
n.Type = nil
return
}
l = args.N
args = args.Next
typecheck(&l, Erv)
var r *Node
if args != nil {
r = args.N
args = args.Next
typecheck(&r, Erv)
}
if l.Type == nil || (r != nil && r.Type == nil) {
n.Type = nil
return
}
et := obj.Bool2int(checkmake(t, "len", l) < 0)
et |= obj.Bool2int(r != nil && checkmake(t, "cap", r) < 0)
if et != 0 {
n.Type = nil
return
}
if Isconst(l, CTINT) && r != nil && Isconst(r, CTINT) && Mpcmpfixfix(l.Val().U.(*Mpint), r.Val().U.(*Mpint)) > 0 {
Yyerror("len larger than cap in make(%v)", t)
n.Type = nil
return
}
n.Left = l
n.Right = r
n.Op = OMAKESLICE
case TMAP:
if args != nil {
l = args.N
args = args.Next
typecheck(&l, Erv)
defaultlit(&l, Types[TINT])
if l.Type == nil {
n.Type = nil
return
}
if checkmake(t, "size", l) < 0 {
n.Type = nil
return
}
n.Left = l
} else {
n.Left = Nodintconst(0)
}
n.Op = OMAKEMAP
case TCHAN:
l = nil
if args != nil {
l = args.N
args = args.Next
typecheck(&l, Erv)
defaultlit(&l, Types[TINT])
if l.Type == nil {
n.Type = nil
return
}
if checkmake(t, "buffer", l) < 0 {
n.Type = nil
return
}
n.Left = l
} else {
n.Left = Nodintconst(0)
}
n.Op = OMAKECHAN
}
if args != nil {
Yyerror("too many arguments to make(%v)", t)
n.Op = OMAKE
n.Type = nil
return
}
n.Type = t
break OpSwitch
case ONEW:
ok |= Erv
args := n.List
if args == nil {
Yyerror("missing argument to new")
n.Type = nil
return
}
l := args.N
typecheck(&l, Etype)
t := l.Type
if t == nil {
n.Type = nil
return
}
if args.Next != nil {
Yyerror("too many arguments to new(%v)", t)
n.Type = nil
return
}
n.Left = l
n.Type = Ptrto(t)
break OpSwitch
case OPRINT, OPRINTN:
ok |= Etop
typechecklist(n.List, Erv|Eindir) // Eindir: address does not escape
for args := n.List; args != nil; args = args.Next {
// Special case for print: int constant is int64, not int.
if Isconst(args.N, CTINT) {
defaultlit(&args.N, Types[TINT64])
} else {
defaultlit(&args.N, nil)
}
}
break OpSwitch
case OPANIC:
ok |= Etop
if onearg(n, "panic") < 0 {
n.Type = nil
return
}
typecheck(&n.Left, Erv)
defaultlit(&n.Left, Types[TINTER])
if n.Left.Type == nil {
n.Type = nil
return
}
break OpSwitch
case ORECOVER:
ok |= Erv | Etop
if n.List != nil {
Yyerror("too many arguments to recover")
n.Type = nil
return
}
n.Type = Types[TINTER]
break OpSwitch
case OCLOSURE:
ok |= Erv
typecheckclosure(n, top)
if n.Type == nil {
n.Type = nil
return
}
break OpSwitch
case OITAB:
ok |= Erv
typecheck(&n.Left, Erv)
t := n.Left.Type
if t == nil {
n.Type = nil
return
}
if t.Etype != TINTER {
Fatalf("OITAB of %v", t)
}
n.Type = Ptrto(Types[TUINTPTR])
break OpSwitch
case OSPTR:
ok |= Erv
typecheck(&n.Left, Erv)
t := n.Left.Type
if t == nil {
n.Type = nil
return
}
if !Isslice(t) && t.Etype != TSTRING {
Fatalf("OSPTR of %v", t)
}
if t.Etype == TSTRING {
n.Type = Ptrto(Types[TUINT8])
} else {
n.Type = Ptrto(t.Type)
}
break OpSwitch
case OCLOSUREVAR:
ok |= Erv
break OpSwitch
case OCFUNC:
ok |= Erv
typecheck(&n.Left, Erv)
n.Type = Types[TUINTPTR]
break OpSwitch
case OCONVNOP:
ok |= Erv
typecheck(&n.Left, Erv)
break OpSwitch
/*
* statements
*/
case OAS:
ok |= Etop
typecheckas(n)
// Code that creates temps does not bother to set defn, so do it here.
if n.Left.Op == ONAME && strings.HasPrefix(n.Left.Sym.Name, "autotmp_") {
n.Left.Name.Defn = n
}
break OpSwitch
case OAS2:
ok |= Etop
typecheckas2(n)
break OpSwitch
case OBREAK,
OCONTINUE,
ODCL,
OEMPTY,
OGOTO,
OXFALL,
OVARKILL:
ok |= Etop
break OpSwitch
case OLABEL:
ok |= Etop
decldepth++
break OpSwitch
case ODEFER:
ok |= Etop
typecheck(&n.Left, Etop|Erv)
if n.Left.Diag == 0 {
checkdefergo(n)
}
break OpSwitch
case OPROC:
ok |= Etop
typecheck(&n.Left, Etop|Eproc|Erv)
checkdefergo(n)
break OpSwitch
case OFOR:
ok |= Etop
typechecklist(n.Ninit, Etop)
decldepth++
typecheck(&n.Left, Erv)
if n.Left != nil {
t := n.Left.Type
if t != nil && t.Etype != TBOOL {
Yyerror("non-bool %v used as for condition", Nconv(n.Left, obj.FmtLong))
}
}
typecheck(&n.Right, Etop)
typechecklist(n.Nbody, Etop)
decldepth--
break OpSwitch
case OIF:
ok |= Etop
typechecklist(n.Ninit, Etop)
typecheck(&n.Left, Erv)
if n.Left != nil {
t := n.Left.Type
if t != nil && t.Etype != TBOOL {
Yyerror("non-bool %v used as if condition", Nconv(n.Left, obj.FmtLong))
}
}
typechecklist(n.Nbody, Etop)
typechecklist(n.Rlist, Etop)
break OpSwitch
case ORETURN:
ok |= Etop
if count(n.List) == 1 {
typechecklist(n.List, Erv|Efnstruct)
} else {
typechecklist(n.List, Erv)
}
if Curfn == nil {
Yyerror("return outside function")
n.Type = nil
return
}
if Curfn.Type.Outnamed && n.List == nil {
break OpSwitch
}
typecheckaste(ORETURN, nil, false, getoutargx(Curfn.Type), n.List, func() string { return "return argument" })
break OpSwitch
case ORETJMP:
ok |= Etop
break OpSwitch
case OSELECT:
ok |= Etop
typecheckselect(n)
break OpSwitch
case OSWITCH:
ok |= Etop
typecheckswitch(n)
break OpSwitch
case ORANGE:
ok |= Etop
typecheckrange(n)
break OpSwitch
case OTYPESW:
Yyerror("use of .(type) outside type switch")
n.Type = nil
return
case OXCASE:
ok |= Etop
typechecklist(n.List, Erv)
typechecklist(n.Nbody, Etop)
break OpSwitch
case ODCLFUNC:
ok |= Etop
typecheckfunc(n)
break OpSwitch
case ODCLCONST:
ok |= Etop
typecheck(&n.Left, Erv)
break OpSwitch
case ODCLTYPE:
ok |= Etop
typecheck(&n.Left, Etype)
if incannedimport == 0 {
checkwidth(n.Left.Type)
}
break OpSwitch
}
t := n.Type
if t != nil && !t.Funarg && n.Op != OTYPE {
switch t.Etype {
case TFUNC, // might have TANY; wait until its called
TANY,
TFORW,
TIDEAL,
TNIL,
TBLANK:
break
default:
checkwidth(t)
}
}
if safemode != 0 && incannedimport == 0 && importpkg == nil && compiling_wrappers == 0 && t != nil && t.Etype == TUNSAFEPTR {
Yyerror("cannot use unsafe.Pointer")
}
evconst(n)
if n.Op == OTYPE && top&Etype == 0 {
Yyerror("type %v is not an expression", n.Type)
n.Type = nil
return
}
if top&(Erv|Etype) == Etype && n.Op != OTYPE {
Yyerror("%v is not a type", n)
n.Type = nil
return
}
// TODO(rsc): simplify
if (top&(Ecall|Erv|Etype) != 0) && top&Etop == 0 && ok&(Erv|Etype|Ecall) == 0 {
Yyerror("%v used as value", n)
n.Type = nil
return
}
if (top&Etop != 0) && top&(Ecall|Erv|Etype) == 0 && ok&Etop == 0 {
if n.Diag == 0 {
Yyerror("%v evaluated but not used", n)
n.Diag = 1
}
n.Type = nil
return
}
/* TODO
if(n->type == T)
fatal("typecheck nil type");
*/
}
func checksliceindex(l *Node, r *Node, tp *Type) int {
t := r.Type
if t == nil {
return -1
}
if !Isint[t.Etype] {
Yyerror("invalid slice index %v (type %v)", r, t)
return -1
}
if r.Op == OLITERAL {
if Mpgetfix(r.Val().U.(*Mpint)) < 0 {
Yyerror("invalid slice index %v (index must be non-negative)", r)
return -1
} else if tp != nil && tp.Bound > 0 && Mpgetfix(r.Val().U.(*Mpint)) > tp.Bound {
Yyerror("invalid slice index %v (out of bounds for %d-element array)", r, tp.Bound)
return -1
} else if Isconst(l, CTSTR) && Mpgetfix(r.Val().U.(*Mpint)) > int64(len(l.Val().U.(string))) {
Yyerror("invalid slice index %v (out of bounds for %d-byte string)", r, len(l.Val().U.(string)))
return -1
} else if Mpcmpfixfix(r.Val().U.(*Mpint), Maxintval[TINT]) > 0 {
Yyerror("invalid slice index %v (index too large)", r)
return -1
}
}
return 0
}
func checksliceconst(lo *Node, hi *Node) int {
if lo != nil && hi != nil && lo.Op == OLITERAL && hi.Op == OLITERAL && Mpcmpfixfix(lo.Val().U.(*Mpint), hi.Val().U.(*Mpint)) > 0 {
Yyerror("invalid slice index: %v > %v", lo, hi)
return -1
}
return 0
}
func checkdefergo(n *Node) {
what := "defer"
if n.Op == OPROC {
what = "go"
}
switch n.Left.Op {
// ok
case OCALLINTER,
OCALLMETH,
OCALLFUNC,
OCLOSE,
OCOPY,
ODELETE,
OPANIC,
OPRINT,
OPRINTN,
ORECOVER:
return
case OAPPEND,
OCAP,
OCOMPLEX,
OIMAG,
OLEN,
OMAKE,
OMAKESLICE,
OMAKECHAN,
OMAKEMAP,
ONEW,
OREAL,
OLITERAL: // conversion or unsafe.Alignof, Offsetof, Sizeof
if n.Left.Orig != nil && n.Left.Orig.Op == OCONV {
break
}
Yyerror("%s discards result of %v", what, n.Left)
return
}
// type is broken or missing, most likely a method call on a broken type
// we will warn about the broken type elsewhere. no need to emit a potentially confusing error
if n.Left.Type == nil || n.Left.Type.Broke {
return
}
if n.Diag == 0 {
// The syntax made sure it was a call, so this must be
// a conversion.
n.Diag = 1
Yyerror("%s requires function call, not conversion", what)
}
}
func implicitstar(nn **Node) {
// insert implicit * if needed for fixed array
n := *nn
t := n.Type
if t == nil || !Isptr[t.Etype] {
return
}
t = t.Type
if t == nil {
return
}
if !Isfixedarray(t) {
return
}
n = Nod(OIND, n, nil)
n.Implicit = true
typecheck(&n, Erv)
*nn = n
}
func onearg(n *Node, f string, args ...interface{}) int {
if n.Left != nil {
return 0
}
if n.List == nil {
p := fmt.Sprintf(f, args...)
Yyerror("missing argument to %s: %v", p, n)
return -1
}
if n.List.Next != nil {
p := fmt.Sprintf(f, args...)
Yyerror("too many arguments to %s: %v", p, n)
n.Left = n.List.N
n.List = nil
return -1
}
n.Left = n.List.N
n.List = nil
return 0
}
func twoarg(n *Node) int {
if n.Left != nil {
return 0
}
if n.List == nil {
Yyerror("missing argument to %v - %v", Oconv(int(n.Op), 0), n)
return -1
}
n.Left = n.List.N
if n.List.Next == nil {
Yyerror("missing argument to %v - %v", Oconv(int(n.Op), 0), n)
n.List = nil
return -1
}
if n.List.Next.Next != nil {
Yyerror("too many arguments to %v - %v", Oconv(int(n.Op), 0), n)
n.List = nil
return -1
}
n.Right = n.List.Next.N
n.List = nil
return 0
}
func lookdot1(errnode *Node, s *Sym, t *Type, f *Type, dostrcmp int) *Type {
var r *Type
for ; f != nil; f = f.Down {
if dostrcmp != 0 && f.Sym.Name == s.Name {
return f
}
if dostrcmp == 2 && strings.EqualFold(f.Sym.Name, s.Name) {
return f
}
if f.Sym != s {
continue
}
if r != nil {
if errnode != nil {
Yyerror("ambiguous selector %v", errnode)
} else if Isptr[t.Etype] {
Yyerror("ambiguous selector (%v).%v", t, s)
} else {
Yyerror("ambiguous selector %v.%v", t, s)
}
break
}
r = f
}
return r
}
func looktypedot(n *Node, t *Type, dostrcmp int) bool {
s := n.Right.Sym
if t.Etype == TINTER {
f1 := lookdot1(n, s, t, t.Type, dostrcmp)
if f1 == nil {
return false
}
n.Right = methodname(n.Right, t)
n.Xoffset = f1.Width
n.Type = f1.Type
n.Op = ODOTINTER
return true
}
// Find the base type: methtype will fail if t
// is not of the form T or *T.
f2 := methtype(t, 0)
if f2 == nil {
return false
}
expandmeth(f2)
f2 = lookdot1(n, s, f2, f2.Xmethod, dostrcmp)
if f2 == nil {
return false
}
// disallow T.m if m requires *T receiver
if Isptr[getthisx(f2.Type).Type.Type.Etype] && !Isptr[t.Etype] && f2.Embedded != 2 && !isifacemethod(f2.Type) {
Yyerror("invalid method expression %v (needs pointer receiver: (*%v).%v)", n, t, Sconv(f2.Sym, obj.FmtShort))
return false
}
n.Right = methodname(n.Right, t)
n.Xoffset = f2.Width
n.Type = f2.Type
n.Op = ODOTMETH
return true
}
func derefall(t *Type) *Type {
for t != nil && int(t.Etype) == Tptr {
t = t.Type
}
return t
}
type typeSym struct {
t *Type
s *Sym
}
// dotField maps (*Type, *Sym) pairs to the corresponding struct field (*Type with Etype==TFIELD).
// It is a cache for use during usefield in walk.go, only enabled when field tracking.
var dotField = map[typeSym]*Type{}
func lookdot(n *Node, t *Type, dostrcmp int) *Type {
s := n.Right.Sym
dowidth(t)
var f1 *Type
if t.Etype == TSTRUCT || t.Etype == TINTER {
f1 = lookdot1(n, s, t, t.Type, dostrcmp)
}
var f2 *Type
if n.Left.Type == t || n.Left.Type.Sym == nil {
f2 = methtype(t, 0)
if f2 != nil {
// Use f2->method, not f2->xmethod: adddot has
// already inserted all the necessary embedded dots.
f2 = lookdot1(n, s, f2, f2.Method, dostrcmp)
}
}
if f1 != nil {
if dostrcmp > 1 {
// Already in the process of diagnosing an error.
return f1
}
if f2 != nil {
Yyerror("%v is both field and method", n.Right.Sym)
}
if f1.Width == BADWIDTH {
Fatalf("lookdot badwidth %v %p", f1, f1)
}
n.Xoffset = f1.Width
n.Type = f1.Type
if obj.Fieldtrack_enabled > 0 {
dotField[typeSym{t.Orig, s}] = f1
}
if t.Etype == TINTER {
if Isptr[n.Left.Type.Etype] {
n.Left = Nod(OIND, n.Left, nil) // implicitstar
n.Left.Implicit = true
typecheck(&n.Left, Erv)
}
n.Op = ODOTINTER
}
return f1
}
if f2 != nil {
if dostrcmp > 1 {
// Already in the process of diagnosing an error.
return f2
}
tt := n.Left.Type
dowidth(tt)
rcvr := getthisx(f2.Type).Type.Type
if !Eqtype(rcvr, tt) {
if int(rcvr.Etype) == Tptr && Eqtype(rcvr.Type, tt) {
checklvalue(n.Left, "call pointer method on")
n.Left = Nod(OADDR, n.Left, nil)
n.Left.Implicit = true
typecheck(&n.Left, Etype|Erv)
} else if int(tt.Etype) == Tptr && int(rcvr.Etype) != Tptr && Eqtype(tt.Type, rcvr) {
n.Left = Nod(OIND, n.Left, nil)
n.Left.Implicit = true
typecheck(&n.Left, Etype|Erv)
} else if int(tt.Etype) == Tptr && int(tt.Type.Etype) == Tptr && Eqtype(derefall(tt), derefall(rcvr)) {
Yyerror("calling method %v with receiver %v requires explicit dereference", n.Right, Nconv(n.Left, obj.FmtLong))
for int(tt.Etype) == Tptr {
// Stop one level early for method with pointer receiver.
if int(rcvr.Etype) == Tptr && int(tt.Type.Etype) != Tptr {
break
}
n.Left = Nod(OIND, n.Left, nil)
n.Left.Implicit = true
typecheck(&n.Left, Etype|Erv)
tt = tt.Type
}
} else {
Fatalf("method mismatch: %v for %v", rcvr, tt)
}
}
pll := n
ll := n.Left
for ll.Left != nil && (ll.Op == ODOT || ll.Op == ODOTPTR || ll.Op == OIND) {
pll = ll
ll = ll.Left
}
if pll.Implicit && Isptr[ll.Type.Etype] && ll.Type.Sym != nil && ll.Type.Sym.Def != nil && ll.Type.Sym.Def.Op == OTYPE {
// It is invalid to automatically dereference a named pointer type when selecting a method.
// Make n->left == ll to clarify error message.
n.Left = ll
return nil
}
n.Right = methodname(n.Right, n.Left.Type)
n.Xoffset = f2.Width
n.Type = f2.Type
// print("lookdot found [%p] %T\n", f2->type, f2->type);
n.Op = ODOTMETH
return f2
}
return nil
}
func nokeys(l *NodeList) bool {
for ; l != nil; l = l.Next {
if l.N.Op == OKEY {
return false
}
}
return true
}
func hasddd(t *Type) bool {
for tl := t.Type; tl != nil; tl = tl.Down {
if tl.Isddd {
return true
}
}
return false
}
func downcount(t *Type) int {
n := 0
for tl := t.Type; tl != nil; tl = tl.Down {
n++
}
return n
}
/*
* typecheck assignment: type list = expression list
*/
func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList, desc func() string) {
var t *Type
var n *Node
var n1 int
var n2 int
lno := int(lineno)
if tstruct.Broke {
goto out
}
n = nil
if nl != nil && nl.Next == nil {
n = nl.N
if n.Type != nil {
if n.Type.Etype == TSTRUCT && n.Type.Funarg {
if !hasddd(tstruct) {
n1 := downcount(tstruct)
n2 := downcount(n.Type)
if n2 > n1 {
goto toomany
}
if n2 < n1 {
goto notenough
}
}
tn := n.Type.Type
var why string
for tl := tstruct.Type; tl != nil; tl = tl.Down {
if tl.Isddd {
for ; tn != nil; tn = tn.Down {
if assignop(tn.Type, tl.Type.Type, &why) == 0 {
if call != nil {
Yyerror("cannot use %v as type %v in argument to %v%s", tn.Type, tl.Type.Type, call, why)
} else {
Yyerror("cannot use %v as type %v in %s%s", tn.Type, tl.Type.Type, desc(), why)
}
}
}
goto out
}
if tn == nil {
goto notenough
}
if assignop(tn.Type, tl.Type, &why) == 0 {
if call != nil {
Yyerror("cannot use %v as type %v in argument to %v%s", tn.Type, tl.Type, call, why)
} else {
Yyerror("cannot use %v as type %v in %s%s", tn.Type, tl.Type, desc(), why)
}
}
tn = tn.Down
}
if tn != nil {
goto toomany
}
goto out
}
}
}
n1 = downcount(tstruct)
n2 = count(nl)
if !hasddd(tstruct) {
if n2 > n1 {
goto toomany
}
if n2 < n1 {
goto notenough
}
} else {
if !isddd {
if n2 < n1-1 {
goto notenough
}
} else {
if n2 > n1 {
goto toomany
}
if n2 < n1 {
goto notenough
}
}
}
for tl := tstruct.Type; tl != nil; tl = tl.Down {
t = tl.Type
if tl.Isddd {
if isddd {
if nl == nil {
goto notenough
}
if nl.Next != nil {
goto toomany
}
n = nl.N
setlineno(n)
if n.Type != nil {
nl.N = assignconvfn(n, t, desc)
}
goto out
}
for ; nl != nil; nl = nl.Next {
n = nl.N
setlineno(nl.N)
if n.Type != nil {
nl.N = assignconvfn(n, t.Type, desc)
}
}
goto out
}
if nl == nil {
goto notenough
}
n = nl.N
setlineno(n)
if n.Type != nil {
nl.N = assignconvfn(n, t, desc)
}
nl = nl.Next
}
if nl != nil {
goto toomany
}
if isddd {
if call != nil {
Yyerror("invalid use of ... in call to %v", call)
} else {
Yyerror("invalid use of ... in %v", Oconv(int(op), 0))
}
}
out:
lineno = int32(lno)
return
notenough:
if n == nil || n.Diag == 0 {
if call != nil {
// call is the expression being called, not the overall call.
// Method expressions have the form T.M, and the compiler has
// rewritten those to ONAME nodes but left T in Left.
if call.Op == ONAME && call.Left != nil && call.Left.Op == OTYPE {
Yyerror("not enough arguments in call to method expression %v", call)
} else {
Yyerror("not enough arguments in call to %v", call)
}
} else {
Yyerror("not enough arguments to %v", Oconv(int(op), 0))
}
if n != nil {
n.Diag = 1
}
}
goto out
toomany:
if call != nil {
Yyerror("too many arguments in call to %v", call)
} else {
Yyerror("too many arguments to %v", Oconv(int(op), 0))
}
goto out
}
/*
* type check composite
*/
func fielddup(n *Node, hash map[string]bool) {
if n.Op != ONAME {
Fatalf("fielddup: not ONAME")
}
name := n.Sym.Name
if hash[name] {
Yyerror("duplicate field name in struct literal: %s", name)
return
}
hash[name] = true
}
func keydup(n *Node, hash map[uint32][]*Node) {
orign := n
if n.Op == OCONVIFACE {
n = n.Left
}
evconst(n)
if n.Op != OLITERAL {
return // we don't check variables
}
var h uint32
switch n.Val().Ctype() {
default: // unknown, bool, nil
h = 23
case CTINT, CTRUNE:
h = uint32(Mpgetfix(n.Val().U.(*Mpint)))
case CTFLT:
d := mpgetflt(n.Val().U.(*Mpflt))
x := math.Float64bits(d)
for i := 0; i < 8; i++ {
h = h*PRIME1 + uint32(x&0xFF)
x >>= 8
}
case CTSTR:
h = 0
s := n.Val().U.(string)
for i := len(n.Val().U.(string)); i > 0; i-- {
h = h*PRIME1 + uint32(s[0])
s = s[1:]
}
}
var cmp Node
for _, a := range hash[h] {
cmp.Op = OEQ
cmp.Left = n
b := uint32(0)
if a.Op == OCONVIFACE && orign.Op == OCONVIFACE {
if Eqtype(a.Left.Type, n.Type) {
cmp.Right = a.Left
evconst(&cmp)
b = uint32(obj.Bool2int(cmp.Val().U.(bool)))
}
} else if Eqtype(a.Type, n.Type) {
cmp.Right = a
evconst(&cmp)
b = uint32(obj.Bool2int(cmp.Val().U.(bool)))
}
if b != 0 {
Yyerror("duplicate key %v in map literal", n)
return
}
}
hash[h] = append(hash[h], orign)
}
func indexdup(n *Node, hash map[int64]*Node) {
if n.Op != OLITERAL {
Fatalf("indexdup: not OLITERAL")
}
v := Mpgetfix(n.Val().U.(*Mpint))
if hash[v] != nil {
Yyerror("duplicate index in array literal: %d", v)
return
}
hash[v] = n
}
func iscomptype(t *Type) bool {
switch t.Etype {
case TARRAY, TSTRUCT, TMAP:
return true
case TPTR32, TPTR64:
switch t.Type.Etype {
case TARRAY, TSTRUCT, TMAP:
return true
}
}
return false
}
func pushtype(n *Node, t *Type) {
if n == nil || n.Op != OCOMPLIT || !iscomptype(t) {
return
}
if n.Right == nil {
n.Right = typenod(t)
n.Implicit = true // don't print
n.Right.Implicit = true // * is okay
} else if Debug['s'] != 0 {
typecheck(&n.Right, Etype)
if n.Right.Type != nil && Eqtype(n.Right.Type, t) {
fmt.Printf("%v: redundant type: %v\n", n.Line(), t)
}
}
}
func typecheckcomplit(np **Node) {
n := *np
lno := lineno
defer func() {
lineno = lno
*np = n
}()
if n.Right == nil {
if n.List != nil {
setlineno(n.List.N)
}
Yyerror("missing type in composite literal")
n.Type = nil
return
}
// Save original node (including n->right)
norig := Nod(int(n.Op), nil, nil)
*norig = *n
setlineno(n.Right)
l := typecheck(&n.Right, Etype|Ecomplit) /* sic */
t := l.Type
if t == nil {
n.Type = nil
return
}
nerr := nerrors
n.Type = t
if Isptr[t.Etype] {
// For better or worse, we don't allow pointers as the composite literal type,
// except when using the &T syntax, which sets implicit on the OIND.
if !n.Right.Implicit {
Yyerror("invalid pointer type %v for composite literal (use &%v instead)", t, t.Type)
n.Type = nil
return
}
// Also, the underlying type must be a struct, map, slice, or array.
if !iscomptype(t) {
Yyerror("invalid pointer type %v for composite literal", t)
n.Type = nil
return
}
t = t.Type
}
var r *Node
switch t.Etype {
default:
Yyerror("invalid type for composite literal: %v", t)
n.Type = nil
case TARRAY:
// Only allocate hash if there are some key/value pairs.
var hash map[int64]*Node
for ll := n.List; ll != nil; ll = ll.Next {
if ll.N.Op == OKEY {
hash = make(map[int64]*Node)
break
}
}
length := int64(0)
i := 0
var l *Node
for ll := n.List; ll != nil; ll = ll.Next {
l = ll.N
setlineno(l)
if l.Op != OKEY {
l = Nod(OKEY, Nodintconst(int64(i)), l)
l.Left.Type = Types[TINT]
l.Left.Typecheck = 1
ll.N = l
}
typecheck(&l.Left, Erv)
evconst(l.Left)
i = nonnegconst(l.Left)
if i < 0 && l.Left.Diag == 0 {
Yyerror("array index must be non-negative integer constant")
l.Left.Diag = 1
i = -(1 << 30) // stay negative for a while
}
if i >= 0 && hash != nil {
indexdup(l.Left, hash)
}
i++
if int64(i) > length {
length = int64(i)
if t.Bound >= 0 && length > t.Bound {
setlineno(l)
Yyerror("array index %d out of bounds [0:%d]", length-1, t.Bound)
t.Bound = -1 // no more errors
}
}
r = l.Right
pushtype(r, t.Type)
typecheck(&r, Erv)
defaultlit(&r, t.Type)
l.Right = assignconv(r, t.Type, "array element")
}
if t.Bound == -100 {
t.Bound = length
}
if t.Bound < 0 {
n.Right = Nodintconst(length)
}
n.Op = OARRAYLIT
case TMAP:
hash := make(map[uint32][]*Node)
var l *Node
for ll := n.List; ll != nil; ll = ll.Next {
l = ll.N
setlineno(l)
if l.Op != OKEY {
typecheck(&ll.N, Erv)
Yyerror("missing key in map literal")
continue
}
r = l.Left
pushtype(r, t.Down)
typecheck(&r, Erv)
defaultlit(&r, t.Down)
l.Left = assignconv(r, t.Down, "map key")
if l.Left.Op != OCONV {
keydup(l.Left, hash)
}
r = l.Right
pushtype(r, t.Type)
typecheck(&r, Erv)
defaultlit(&r, t.Type)
l.Right = assignconv(r, t.Type, "map value")
}
n.Op = OMAPLIT
case TSTRUCT:
bad := 0
if n.List != nil && nokeys(n.List) {
// simple list of variables
f := t.Type
var s *Sym
for ll := n.List; ll != nil; ll = ll.Next {
setlineno(ll.N)
typecheck(&ll.N, Erv)
if f == nil {
if bad == 0 {
Yyerror("too many values in struct initializer")
}
bad++
continue
}
s = f.Sym
if s != nil && !exportname(s.Name) && s.Pkg != localpkg {
Yyerror("implicit assignment of unexported field '%s' in %v literal", s.Name, t)
}
// No pushtype allowed here. Must name fields for that.
ll.N = assignconv(ll.N, f.Type, "field value")
ll.N = Nod(OKEY, newname(f.Sym), ll.N)
ll.N.Left.Type = f
ll.N.Left.Typecheck = 1
f = f.Down
}
if f != nil {
Yyerror("too few values in struct initializer")
}
} else {
hash := make(map[string]bool)
// keyed list
var s *Sym
var f *Type
var l *Node
var s1 *Sym
for ll := n.List; ll != nil; ll = ll.Next {
l = ll.N
setlineno(l)
if l.Op != OKEY {
if bad == 0 {
Yyerror("mixture of field:value and value initializers")
}
bad++
typecheck(&ll.N, Erv)
continue
}
s = l.Left.Sym
if s == nil {
Yyerror("invalid field name %v in struct initializer", l.Left)
typecheck(&l.Right, Erv)
continue
}
// Sym might have resolved to name in other top-level
// package, because of import dot. Redirect to correct sym
// before we do the lookup.
if s.Pkg != localpkg && exportname(s.Name) {
s1 = Lookup(s.Name)
if s1.Origpkg == s.Pkg {
s = s1
}
}
f = lookdot1(nil, s, t, t.Type, 0)
if f == nil {
Yyerror("unknown %v field '%v' in struct literal", t, s)
continue
}
l.Left = newname(s)
l.Left.Typecheck = 1
l.Left.Type = f
s = f.Sym
fielddup(newname(s), hash)
r = l.Right
// No pushtype allowed here. Tried and rejected.
typecheck(&r, Erv)
l.Right = assignconv(r, f.Type, "field value")
}
}
n.Op = OSTRUCTLIT
}
if nerr != nerrors {
n.Type = nil
return
}
n.Orig = norig
if Isptr[n.Type.Etype] {
n = Nod(OPTRLIT, n, nil)
n.Typecheck = 1
n.Type = n.Left.Type
n.Left.Type = t
n.Left.Typecheck = 1
}
n.Orig = norig
return
}
/*
* lvalue etc
*/
func islvalue(n *Node) bool {
switch n.Op {
case OINDEX:
if Isfixedarray(n.Left.Type) {
return islvalue(n.Left)
}
if n.Left.Type != nil && n.Left.Type.Etype == TSTRING {
return false
}
fallthrough
// fall through
case OIND, ODOTPTR, OCLOSUREVAR, OPARAM:
return true
case ODOT:
return islvalue(n.Left)
case ONAME:
if n.Class == PFUNC {
return false
}
return true
}
return false
}
func checklvalue(n *Node, verb string) {
if !islvalue(n) {
Yyerror("cannot %s %v", verb, n)
}
}
func checkassign(stmt *Node, n *Node) {
// Variables declared in ORANGE are assigned on every iteration.
if n.Name == nil || n.Name.Defn != stmt || stmt.Op == ORANGE {
r := outervalue(n)
var l *Node
for l = n; l != r; l = l.Left {
l.Assigned = true
if l.Name != nil && l.Name.Param != nil && l.Name.Param.Closure != nil {
l.Name.Param.Closure.Assigned = true
}
}
l.Assigned = true
if l.Name != nil && l.Name.Param != nil && l.Name.Param.Closure != nil {
l.Name.Param.Closure.Assigned = true
}
}
if islvalue(n) {
return
}
if n.Op == OINDEXMAP {
n.Etype = 1
return
}
// have already complained about n being undefined
if n.Op == ONONAME {
return
}
Yyerror("cannot assign to %v", n)
}
func checkassignlist(stmt *Node, l *NodeList) {
for ; l != nil; l = l.Next {
checkassign(stmt, l.N)
}
}
// Check whether l and r are the same side effect-free expression,
// so that it is safe to reuse one instead of computing both.
func samesafeexpr(l *Node, r *Node) bool {
if l.Op != r.Op || !Eqtype(l.Type, r.Type) {
return false
}
switch l.Op {
case ONAME, OCLOSUREVAR:
return l == r
case ODOT, ODOTPTR:
return l.Right != nil && r.Right != nil && l.Right.Sym == r.Right.Sym && samesafeexpr(l.Left, r.Left)
case OIND:
return samesafeexpr(l.Left, r.Left)
case OINDEX:
return samesafeexpr(l.Left, r.Left) && samesafeexpr(l.Right, r.Right)
}
return false
}
/*
* type check assignment.
* if this assignment is the definition of a var on the left side,
* fill in the var's type.
*/
func typecheckas(n *Node) {
// delicate little dance.
// the definition of n may refer to this assignment
// as its definition, in which case it will call typecheckas.
// in that case, do not call typecheck back, or it will cycle.
// if the variable has a type (ntype) then typechecking
// will not look at defn, so it is okay (and desirable,
// so that the conversion below happens).
n.Left = resolve(n.Left)
if n.Left.Name == nil || n.Left.Name.Defn != n || n.Left.Name.Param.Ntype != nil {
typecheck(&n.Left, Erv|Easgn)
}
typecheck(&n.Right, Erv)
checkassign(n, n.Left)
if n.Right != nil && n.Right.Type != nil {
if n.Left.Type != nil {
n.Right = assignconv(n.Right, n.Left.Type, "assignment")
}
}
if n.Left.Name != nil && n.Left.Name.Defn == n && n.Left.Name.Param.Ntype == nil {
defaultlit(&n.Right, nil)
n.Left.Type = n.Right.Type
}
// second half of dance.
// now that right is done, typecheck the left
// just to get it over with. see dance above.
n.Typecheck = 1
if n.Left.Typecheck == 0 {
typecheck(&n.Left, Erv|Easgn)
}
}
func checkassignto(src *Type, dst *Node) {
var why string
if assignop(src, dst.Type, &why) == 0 {
Yyerror("cannot assign %v to %v in multiple assignment%s", src, Nconv(dst, obj.FmtLong), why)
return
}
}
func typecheckas2(n *Node) {
for ll := n.List; ll != nil; ll = ll.Next {
// delicate little dance.
ll.N = resolve(ll.N)
if ll.N.Name == nil || ll.N.Name.Defn != n || ll.N.Name.Param.Ntype != nil {
typecheck(&ll.N, Erv|Easgn)
}
}
cl := count(n.List)
cr := count(n.Rlist)
if cl > 1 && cr == 1 {
typecheck(&n.Rlist.N, Erv|Efnstruct)
} else {
typechecklist(n.Rlist, Erv)
}
checkassignlist(n, n.List)
var l *Node
var r *Node
if cl == cr {
// easy
ll := n.List
lr := n.Rlist
for ; ll != nil; ll, lr = ll.Next, lr.Next {
if ll.N.Type != nil && lr.N.Type != nil {
lr.N = assignconv(lr.N, ll.N.Type, "assignment")
}
if ll.N.Name != nil && ll.N.Name.Defn == n && ll.N.Name.Param.Ntype == nil {
defaultlit(&lr.N, nil)
ll.N.Type = lr.N.Type
}
}
goto out
}
l = n.List.N
r = n.Rlist.N
// x,y,z = f()
if cr == 1 {
if r.Type == nil {
goto out
}
switch r.Op {
case OCALLMETH, OCALLINTER, OCALLFUNC:
if r.Type.Etype != TSTRUCT || !r.Type.Funarg {
break
}
cr = structcount(r.Type)
if cr != cl {
goto mismatch
}
n.Op = OAS2FUNC
var s Iter
t := Structfirst(&s, &r.Type)
for ll := n.List; ll != nil; ll = ll.Next {
if t.Type != nil && ll.N.Type != nil {
checkassignto(t.Type, ll.N)
}
if ll.N.Name != nil && ll.N.Name.Defn == n && ll.N.Name.Param.Ntype == nil {
ll.N.Type = t.Type
}
t = structnext(&s)
}
goto out
}
}
// x, ok = y
if cl == 2 && cr == 1 {
if r.Type == nil {
goto out
}
switch r.Op {
case OINDEXMAP, ORECV, ODOTTYPE:
switch r.Op {
case OINDEXMAP:
n.Op = OAS2MAPR
case ORECV:
n.Op = OAS2RECV
case ODOTTYPE:
n.Op = OAS2DOTTYPE
r.Op = ODOTTYPE2
}
if l.Type != nil {
checkassignto(r.Type, l)
}
if l.Name != nil && l.Name.Defn == n {
l.Type = r.Type
}
l := n.List.Next.N
if l.Type != nil && l.Type.Etype != TBOOL {
checkassignto(Types[TBOOL], l)
}
if l.Name != nil && l.Name.Defn == n && l.Name.Param.Ntype == nil {
l.Type = Types[TBOOL]
}
goto out
}
}
mismatch:
Yyerror("assignment count mismatch: %d = %d", cl, cr)
// second half of dance
out:
n.Typecheck = 1
for ll := n.List; ll != nil; ll = ll.Next {
if ll.N.Typecheck == 0 {
typecheck(&ll.N, Erv|Easgn)
}
}
}
/*
* type check function definition
*/
func typecheckfunc(n *Node) {
typecheck(&n.Func.Nname, Erv|Easgn)
t := n.Func.Nname.Type
if t == nil {
return
}
n.Type = t
t.Nname = n.Func.Nname
rcvr := getthisx(t).Type
if rcvr != nil && n.Func.Shortname != nil && !isblank(n.Func.Shortname) {
addmethod(n.Func.Shortname.Sym, t, true, n.Func.Nname.Nointerface)
}
for l := n.Func.Dcl; l != nil; l = l.Next {
if l.N.Op == ONAME && (l.N.Class == PPARAM || l.N.Class == PPARAMOUT) {
l.N.Name.Decldepth = 1
}
}
}
func stringtoarraylit(np **Node) {
n := *np
if n.Left.Op != OLITERAL || n.Left.Val().Ctype() != CTSTR {
Fatalf("stringtoarraylit %v", n)
}
s := n.Left.Val().U.(string)
var l *NodeList
if n.Type.Type.Etype == TUINT8 {
// []byte
for i := 0; i < len(s); i++ {
l = list(l, Nod(OKEY, Nodintconst(int64(i)), Nodintconst(int64(s[0]))))
}
} else {
// []rune
i := 0
for _, r := range s {
l = list(l, Nod(OKEY, Nodintconst(int64(i)), Nodintconst(int64(r))))
i++
}
}
nn := Nod(OCOMPLIT, nil, typenod(n.Type))
nn.List = l
typecheck(&nn, Erv)
*np = nn
}
var ntypecheckdeftype int
var methodqueue *NodeList
func domethod(n *Node) {
nt := n.Type.Nname
typecheck(&nt, Etype)
if nt.Type == nil {
// type check failed; leave empty func
n.Type.Etype = TFUNC
n.Type.Nod = nil
return
}
// If we have
// type I interface {
// M(_ int)
// }
// then even though I.M looks like it doesn't care about the
// value of its argument, a specific implementation of I may
// care. The _ would suppress the assignment to that argument
// while generating a call, so remove it.
for t := getinargx(nt.Type).Type; t != nil; t = t.Down {
if t.Sym != nil && t.Sym.Name == "_" {
t.Sym = nil
}
}
*n.Type = *nt.Type
n.Type.Nod = nil
checkwidth(n.Type)
}
var mapqueue *NodeList
func copytype(n *Node, t *Type) {
if t.Etype == TFORW {
// This type isn't computed yet; when it is, update n.
t.Copyto = list(t.Copyto, n)
return
}
maplineno := int(n.Type.Maplineno)
embedlineno := int(n.Type.Embedlineno)
l := n.Type.Copyto
*n.Type = *t
t = n.Type
t.Sym = n.Sym
t.Local = n.Local
if n.Name != nil {
t.Vargen = n.Name.Vargen
}
t.Method = nil
t.Xmethod = nil
t.Nod = nil
t.Printed = false
t.Deferwidth = false
t.Copyto = nil
// Update nodes waiting on this type.
for ; l != nil; l = l.Next {
copytype(l.N, t)
}
// Double-check use of type as embedded type.
lno := int(lineno)
if embedlineno != 0 {
lineno = int32(embedlineno)
if Isptr[t.Etype] {
Yyerror("embedded type cannot be a pointer")
}
}
lineno = int32(lno)
// Queue check for map until all the types are done settling.
if maplineno != 0 {
t.Maplineno = int32(maplineno)
mapqueue = list(mapqueue, n)
}
}
func typecheckdeftype(n *Node) {
ntypecheckdeftype++
lno := int(lineno)
setlineno(n)
n.Type.Sym = n.Sym
n.Typecheck = 1
typecheck(&n.Name.Param.Ntype, Etype)
t := n.Name.Param.Ntype.Type
if t == nil {
n.Diag = 1
n.Type = nil
goto ret
}
if n.Type == nil {
n.Diag = 1
goto ret
}
// copy new type and clear fields
// that don't come along.
// anything zeroed here must be zeroed in
// typedcl2 too.
copytype(n, t)
ret:
lineno = int32(lno)
// if there are no type definitions going on, it's safe to
// try to resolve the method types for the interfaces
// we just read.
if ntypecheckdeftype == 1 {
var l *NodeList
for {
l = methodqueue
if l == nil {
break
}
methodqueue = nil
for ; l != nil; l = l.Next {
domethod(l.N)
}
}
for l := mapqueue; l != nil; l = l.Next {
lineno = l.N.Type.Maplineno
maptype(l.N.Type, Types[TBOOL])
}
lineno = int32(lno)
}
ntypecheckdeftype--
}
func queuemethod(n *Node) {
if ntypecheckdeftype == 0 {
domethod(n)
return
}
methodqueue = list(methodqueue, n)
}
func typecheckdef(n *Node) *Node {
lno := int(lineno)
setlineno(n)
if n.Op == ONONAME {
if n.Diag == 0 {
n.Diag = 1
if n.Lineno != 0 {
lineno = n.Lineno
}
// Note: adderrorname looks for this string and
// adds context about the outer expression
Yyerror("undefined: %v", n.Sym)
}
return n
}
if n.Walkdef == 1 {
return n
}
l := new(NodeList)
l.N = n
l.Next = typecheckdefstack
typecheckdefstack = l
if n.Walkdef == 2 {
Flusherrors()
fmt.Printf("typecheckdef loop:")
for l := typecheckdefstack; l != nil; l = l.Next {
fmt.Printf(" %v", l.N.Sym)
}
fmt.Printf("\n")
Fatalf("typecheckdef loop")
}
n.Walkdef = 2
if n.Type != nil || n.Sym == nil { // builtin or no name
goto ret
}
switch n.Op {
default:
Fatalf("typecheckdef %v", Oconv(int(n.Op), 0))
// not really syms
case OGOTO, OLABEL:
break
case OLITERAL:
if n.Name.Param.Ntype != nil {
typecheck(&n.Name.Param.Ntype, Etype)
n.Type = n.Name.Param.Ntype.Type
n.Name.Param.Ntype = nil
if n.Type == nil {
n.Diag = 1
goto ret
}
}
e := n.Name.Defn
n.Name.Defn = nil
if e == nil {
lineno = n.Lineno
Dump("typecheckdef nil defn", n)
Yyerror("xxx")
}
typecheck(&e, Erv|Eiota)
if Isconst(e, CTNIL) {
Yyerror("const initializer cannot be nil")
goto ret
}
if e.Type != nil && e.Op != OLITERAL || !isgoconst(e) {
if e.Diag == 0 {
Yyerror("const initializer %v is not a constant", e)
e.Diag = 1
}
goto ret
}
t := n.Type
if t != nil {
if !okforconst[t.Etype] {
Yyerror("invalid constant type %v", t)
goto ret
}
if !isideal(e.Type) && !Eqtype(t, e.Type) {
Yyerror("cannot use %v as type %v in const initializer", Nconv(e, obj.FmtLong), t)
goto ret
}
Convlit(&e, t)
}
n.SetVal(e.Val())
n.Type = e.Type
case ONAME:
if n.Name.Param.Ntype != nil {
typecheck(&n.Name.Param.Ntype, Etype)
n.Type = n.Name.Param.Ntype.Type
if n.Type == nil {
n.Diag = 1
goto ret
}
}
if n.Type != nil {
break
}
if n.Name.Defn == nil {
if n.Etype != 0 { // like OPRINTN
break
}
if nsavederrors+nerrors > 0 {
// Can have undefined variables in x := foo
// that make x have an n->ndefn == nil.
// If there are other errors anyway, don't
// bother adding to the noise.
break
}
Fatalf("var without type, init: %v", n.Sym)
}
if n.Name.Defn.Op == ONAME {
typecheck(&n.Name.Defn, Erv)
n.Type = n.Name.Defn.Type
break
}
typecheck(&n.Name.Defn, Etop) // fills in n->type
case OTYPE:
if Curfn != nil {
defercheckwidth()
}
n.Walkdef = 1
n.Type = typ(TFORW)
n.Type.Sym = n.Sym
nerrors0 := nerrors
typecheckdeftype(n)
if n.Type.Etype == TFORW && nerrors > nerrors0 {
// Something went wrong during type-checking,
// but it was reported. Silence future errors.
n.Type.Broke = true
}
if Curfn != nil {
resumecheckwidth()
}
// nothing to see here
case OPACK:
break
}
ret:
if n.Op != OLITERAL && n.Type != nil && isideal(n.Type) {
Fatalf("got %v for %v", n.Type, n)
}
if typecheckdefstack.N != n {
Fatalf("typecheckdefstack mismatch")
}
l = typecheckdefstack
typecheckdefstack = l.Next
lineno = int32(lno)
n.Walkdef = 1
return n
}
func checkmake(t *Type, arg string, n *Node) int {
if n.Op == OLITERAL {
switch n.Val().Ctype() {
case CTINT, CTRUNE, CTFLT, CTCPLX:
n.SetVal(toint(n.Val()))
if mpcmpfixc(n.Val().U.(*Mpint), 0) < 0 {
Yyerror("negative %s argument in make(%v)", arg, t)
return -1
}
if Mpcmpfixfix(n.Val().U.(*Mpint), Maxintval[TINT]) > 0 {
Yyerror("%s argument too large in make(%v)", arg, t)
return -1
}
// Delay defaultlit until after we've checked range, to avoid
// a redundant "constant NNN overflows int" error.
defaultlit(&n, Types[TINT])
return 0
default:
break
}
}
if !Isint[n.Type.Etype] && n.Type.Etype != TIDEAL {
Yyerror("non-integer %s argument in make(%v) - %v", arg, t, n.Type)
return -1
}
// Defaultlit still necessary for non-constant: n might be 1<<k.
defaultlit(&n, Types[TINT])
return 0
}
func markbreak(n *Node, implicit *Node) {
if n == nil {
return
}
switch n.Op {
case OBREAK:
if n.Left == nil {
if implicit != nil {
implicit.Hasbreak = true
}
} else {
lab := n.Left.Sym.Label
if lab != nil {
lab.Def.Hasbreak = true
}
}
case OFOR,
OSWITCH,
OTYPESW,
OSELECT,
ORANGE:
implicit = n
fallthrough
// fall through
default:
markbreak(n.Left, implicit)
markbreak(n.Right, implicit)
markbreaklist(n.Ninit, implicit)
markbreaklist(n.Nbody, implicit)
markbreaklist(n.List, implicit)
markbreaklist(n.Rlist, implicit)
}
}
func markbreaklist(l *NodeList, implicit *Node) {
var n *Node
var lab *Label
for ; l != nil; l = l.Next {
n = l.N
if n.Op == OLABEL && l.Next != nil && n.Name.Defn == l.Next.N {
switch n.Name.Defn.Op {
case OFOR,
OSWITCH,
OTYPESW,
OSELECT,
ORANGE:
lab = new(Label)
lab.Def = n.Name.Defn
n.Left.Sym.Label = lab
markbreak(n.Name.Defn, n.Name.Defn)
n.Left.Sym.Label = nil
l = l.Next
continue
}
}
markbreak(n, implicit)
}
}
func isterminating(l *NodeList, top int) bool {
if l == nil {
return false
}
if top != 0 {
for l.Next != nil && l.N.Op != OLABEL {
l = l.Next
}
markbreaklist(l, nil)
}
for l.Next != nil {
l = l.Next
}
n := l.N
if n == nil {
return false
}
switch n.Op {
// NOTE: OLABEL is treated as a separate statement,
// not a separate prefix, so skipping to the last statement
// in the block handles the labeled statement case by
// skipping over the label. No case OLABEL here.
case OBLOCK:
return isterminating(n.List, 0)
case OGOTO,
ORETURN,
ORETJMP,
OPANIC,
OXFALL:
return true
case OFOR:
if n.Left != nil {
return false
}
if n.Hasbreak {
return false
}
return true
case OIF:
return isterminating(n.Nbody, 0) && isterminating(n.Rlist, 0)
case OSWITCH, OTYPESW, OSELECT:
if n.Hasbreak {
return false
}
def := 0
for l = n.List; l != nil; l = l.Next {
if !isterminating(l.N.Nbody, 0) {
return false
}
if l.N.List == nil { // default
def = 1
}
}
if n.Op != OSELECT && def == 0 {
return false
}
return true
}
return false
}
func checkreturn(fn *Node) {
if fn.Type.Outtuple != 0 && fn.Nbody != nil {
if !isterminating(fn.Nbody, 1) {
yyerrorl(int(fn.Func.Endlineno), "missing return at end of function")
}
}
}