File size: 3,604 Bytes
fc11197 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | // Copyright 2021 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 noder
import (
"go/constant"
"cmd/compile/internal/ir"
"cmd/compile/internal/syntax"
"cmd/compile/internal/typecheck"
"cmd/compile/internal/types"
"cmd/compile/internal/types2"
"cmd/internal/src"
)
// Helpers for constructing typed IR nodes.
//
// TODO(mdempsky): Move into their own package so they can be easily
// reused by iimport and frontend optimizations.
type ImplicitNode interface {
ir.Node
SetImplicit(x bool)
}
// Implicit returns n after marking it as Implicit.
func Implicit(n ImplicitNode) ImplicitNode {
n.SetImplicit(true)
return n
}
// typed returns n after setting its type to typ.
func typed(typ *types.Type, n ir.Node) ir.Node {
n.SetType(typ)
n.SetTypecheck(1)
return n
}
// Values
// FixValue returns val after converting and truncating it as
// appropriate for typ.
func FixValue(typ *types.Type, val constant.Value) constant.Value {
assert(typ.Kind() != types.TFORW)
switch {
case typ.IsInteger():
val = constant.ToInt(val)
case typ.IsFloat():
val = constant.ToFloat(val)
case typ.IsComplex():
val = constant.ToComplex(val)
}
if !typ.IsUntyped() {
val = typecheck.ConvertVal(val, typ, false)
}
ir.AssertValidTypeForConst(typ, val)
return val
}
// Expressions
func Addr(pos src.XPos, x ir.Node) *ir.AddrExpr {
n := typecheck.NodAddrAt(pos, x)
typed(types.NewPtr(x.Type()), n)
return n
}
func Deref(pos src.XPos, typ *types.Type, x ir.Node) *ir.StarExpr {
n := ir.NewStarExpr(pos, x)
typed(typ, n)
return n
}
// Statements
func idealType(tv syntax.TypeAndValue) types2.Type {
// The gc backend expects all expressions to have a concrete type, and
// types2 mostly satisfies this expectation already. But there are a few
// cases where the Go spec doesn't require converting to concrete type,
// and so types2 leaves them untyped. So we need to fix those up here.
typ := types2.Unalias(tv.Type)
if basic, ok := typ.(*types2.Basic); ok && basic.Info()&types2.IsUntyped != 0 {
switch basic.Kind() {
case types2.UntypedNil:
// ok; can appear in type switch case clauses
// TODO(mdempsky): Handle as part of type switches instead?
case types2.UntypedInt, types2.UntypedFloat, types2.UntypedComplex:
typ = types2.Typ[types2.Uint]
if tv.Value != nil {
s := constant.ToInt(tv.Value)
assert(s.Kind() == constant.Int)
if constant.Sign(s) < 0 {
typ = types2.Typ[types2.Int]
}
}
case types2.UntypedBool:
typ = types2.Typ[types2.Bool] // expression in "if" or "for" condition
case types2.UntypedString:
typ = types2.Typ[types2.String] // argument to "append" or "copy" calls
case types2.UntypedRune:
typ = types2.Typ[types2.Int32] // range over rune
default:
return nil
}
}
return typ
}
func isTypeParam(t types2.Type) bool {
_, ok := types2.Unalias(t).(*types2.TypeParam)
return ok
}
// isNotInHeap reports whether typ is or contains an element of type
// internal/runtime/sys.NotInHeap.
func isNotInHeap(typ types2.Type) bool {
typ = types2.Unalias(typ)
if named, ok := typ.(*types2.Named); ok {
if obj := named.Obj(); obj.Name() == "nih" && obj.Pkg().Path() == "internal/runtime/sys" {
return true
}
typ = named.Underlying()
}
switch typ := typ.(type) {
case *types2.Array:
return isNotInHeap(typ.Elem())
case *types2.Struct:
for i := 0; i < typ.NumFields(); i++ {
if isNotInHeap(typ.Field(i).Type()) {
return true
}
}
return false
default:
return false
}
}
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