go builtin 源码
golang builtin 代码
文件路径：/src/cmd/compile/internal/walk/builtin.go
// 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 walk
import (
"fmt"
"go/constant"
"go/token"
"strings"
"cmd/compile/internal/base"
"cmd/compile/internal/escape"
"cmd/compile/internal/ir"
"cmd/compile/internal/reflectdata"
"cmd/compile/internal/typecheck"
"cmd/compile/internal/types"
)
// Rewrite append(src, x, y, z) so that any side effects in
// x, y, z (including runtime panics) are evaluated in
// initialization statements before the append.
// For normal code generation, stop there and leave the
// rest to cgen_append.
//
// For race detector, expand append(src, a [, b]* ) to
//
// init {
// s := src
// const argc = len(args) - 1
// if cap(s) - len(s) < argc {
// s = growslice(s, len(s)+argc)
// }
// n := len(s)
// s = s[:n+argc]
// s[n] = a
// s[n+1] = b
// ...
// }
// s
func walkAppend(n *ir.CallExpr, init *ir.Nodes, dst ir.Node) ir.Node {
if !ir.SameSafeExpr(dst, n.Args[0]) {
n.Args[0] = safeExpr(n.Args[0], init)
n.Args[0] = walkExpr(n.Args[0], init)
}
walkExprListSafe(n.Args[1:], init)
nsrc := n.Args[0]
// walkExprListSafe will leave OINDEX (s[n]) alone if both s
// and n are name or literal, but those may index the slice we're
// modifying here. Fix explicitly.
// Using cheapExpr also makes sure that the evaluation
// of all arguments (and especially any panics) happen
// before we begin to modify the slice in a visible way.
ls := n.Args[1:]
for i, n := range ls {
n = cheapExpr(n, init)
if !types.Identical(n.Type(), nsrc.Type().Elem()) {
n = typecheck.AssignConv(n, nsrc.Type().Elem(), "append")
n = walkExpr(n, init)
}
ls[i] = n
}
argc := len(n.Args) - 1
if argc < 1 {
return nsrc
}
// General case, with no function calls left as arguments.
// Leave for gen, except that instrumentation requires old form.
if !base.Flag.Cfg.Instrumenting || base.Flag.CompilingRuntime {
return n
}
var l []ir.Node
ns := typecheck.Temp(nsrc.Type())
l = append(l, ir.NewAssignStmt(base.Pos, ns, nsrc)) // s = src
na := ir.NewInt(int64(argc)) // const argc
nif := ir.NewIfStmt(base.Pos, nil, nil, nil) // if cap(s) - len(s) < argc
nif.Cond = ir.NewBinaryExpr(base.Pos, ir.OLT, ir.NewBinaryExpr(base.Pos, ir.OSUB, ir.NewUnaryExpr(base.Pos, ir.OCAP, ns), ir.NewUnaryExpr(base.Pos, ir.OLEN, ns)), na)
fn := typecheck.LookupRuntime("growslice") // growslice(<type>, old []T, mincap int) (ret []T)
fn = typecheck.SubstArgTypes(fn, ns.Type().Elem(), ns.Type().Elem())
nif.Body = []ir.Node{ir.NewAssignStmt(base.Pos, ns, mkcall1(fn, ns.Type(), nif.PtrInit(), reflectdata.TypePtr(ns.Type().Elem()), ns,
ir.NewBinaryExpr(base.Pos, ir.OADD, ir.NewUnaryExpr(base.Pos, ir.OLEN, ns), na)))}
l = append(l, nif)
nn := typecheck.Temp(types.Types[types.TINT])
l = append(l, ir.NewAssignStmt(base.Pos, nn, ir.NewUnaryExpr(base.Pos, ir.OLEN, ns))) // n = len(s)
slice := ir.NewSliceExpr(base.Pos, ir.OSLICE, ns, nil, ir.NewBinaryExpr(base.Pos, ir.OADD, nn, na), nil) // ...s[:n+argc]
slice.SetBounded(true)
l = append(l, ir.NewAssignStmt(base.Pos, ns, slice)) // s = s[:n+argc]
ls = n.Args[1:]
for i, n := range ls {
ix := ir.NewIndexExpr(base.Pos, ns, nn) // s[n] ...
ix.SetBounded(true)
l = append(l, ir.NewAssignStmt(base.Pos, ix, n)) // s[n] = arg
if i+1 < len(ls) {
l = append(l, ir.NewAssignStmt(base.Pos, nn, ir.NewBinaryExpr(base.Pos, ir.OADD, nn, ir.NewInt(1)))) // n = n + 1
}
}
typecheck.Stmts(l)
walkStmtList(l)
init.Append(l...)
return ns
}
// walkClose walks an OCLOSE node.
func walkClose(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
// cannot use chanfn - closechan takes any, not chan any
fn := typecheck.LookupRuntime("closechan")
fn = typecheck.SubstArgTypes(fn, n.X.Type())
return mkcall1(fn, nil, init, n.X)
}
// Lower copy(a, b) to a memmove call or a runtime call.
//
// init {
// n := len(a)
// if n > len(b) { n = len(b) }
// if a.ptr != b.ptr { memmove(a.ptr, b.ptr, n*sizeof(elem(a))) }
// }
// n;
//
// Also works if b is a string.
func walkCopy(n *ir.BinaryExpr, init *ir.Nodes, runtimecall bool) ir.Node {
if n.X.Type().Elem().HasPointers() {
ir.CurFunc.SetWBPos(n.Pos())
fn := writebarrierfn("typedslicecopy", n.X.Type().Elem(), n.Y.Type().Elem())
n.X = cheapExpr(n.X, init)
ptrL, lenL := backingArrayPtrLen(n.X)
n.Y = cheapExpr(n.Y, init)
ptrR, lenR := backingArrayPtrLen(n.Y)
return mkcall1(fn, n.Type(), init, reflectdata.TypePtr(n.X.Type().Elem()), ptrL, lenL, ptrR, lenR)
}
if runtimecall {
// rely on runtime to instrument:
// copy(n.Left, n.Right)
// n.Right can be a slice or string.
n.X = cheapExpr(n.X, init)
ptrL, lenL := backingArrayPtrLen(n.X)
n.Y = cheapExpr(n.Y, init)
ptrR, lenR := backingArrayPtrLen(n.Y)
fn := typecheck.LookupRuntime("slicecopy")
fn = typecheck.SubstArgTypes(fn, ptrL.Type().Elem(), ptrR.Type().Elem())
return mkcall1(fn, n.Type(), init, ptrL, lenL, ptrR, lenR, ir.NewInt(n.X.Type().Elem().Size()))
}
n.X = walkExpr(n.X, init)
n.Y = walkExpr(n.Y, init)
nl := typecheck.Temp(n.X.Type())
nr := typecheck.Temp(n.Y.Type())
var l []ir.Node
l = append(l, ir.NewAssignStmt(base.Pos, nl, n.X))
l = append(l, ir.NewAssignStmt(base.Pos, nr, n.Y))
nfrm := ir.NewUnaryExpr(base.Pos, ir.OSPTR, nr)
nto := ir.NewUnaryExpr(base.Pos, ir.OSPTR, nl)
nlen := typecheck.Temp(types.Types[types.TINT])
// n = len(to)
l = append(l, ir.NewAssignStmt(base.Pos, nlen, ir.NewUnaryExpr(base.Pos, ir.OLEN, nl)))
// if n > len(frm) { n = len(frm) }
nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
nif.Cond = ir.NewBinaryExpr(base.Pos, ir.OGT, nlen, ir.NewUnaryExpr(base.Pos, ir.OLEN, nr))
nif.Body.Append(ir.NewAssignStmt(base.Pos, nlen, ir.NewUnaryExpr(base.Pos, ir.OLEN, nr)))
l = append(l, nif)
// if to.ptr != frm.ptr { memmove( ... ) }
ne := ir.NewIfStmt(base.Pos, ir.NewBinaryExpr(base.Pos, ir.ONE, nto, nfrm), nil, nil)
ne.Likely = true
l = append(l, ne)
fn := typecheck.LookupRuntime("memmove")
fn = typecheck.SubstArgTypes(fn, nl.Type().Elem(), nl.Type().Elem())
nwid := ir.Node(typecheck.Temp(types.Types[types.TUINTPTR]))
setwid := ir.NewAssignStmt(base.Pos, nwid, typecheck.Conv(nlen, types.Types[types.TUINTPTR]))
ne.Body.Append(setwid)
nwid = ir.NewBinaryExpr(base.Pos, ir.OMUL, nwid, ir.NewInt(nl.Type().Elem().Size()))
call := mkcall1(fn, nil, init, nto, nfrm, nwid)
ne.Body.Append(call)
typecheck.Stmts(l)
walkStmtList(l)
init.Append(l...)
return nlen
}
// walkDelete walks an ODELETE node.
func walkDelete(init *ir.Nodes, n *ir.CallExpr) ir.Node {
init.Append(ir.TakeInit(n)...)
map_ := n.Args[0]
key := n.Args[1]
map_ = walkExpr(map_, init)
key = walkExpr(key, init)
t := map_.Type()
fast := mapfast(t)
key = mapKeyArg(fast, n, key, false)
return mkcall1(mapfndel(mapdelete[fast], t), nil, init, reflectdata.TypePtr(t), map_, key)
}
// walkLenCap walks an OLEN or OCAP node.
func walkLenCap(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
if isRuneCount(n) {
// Replace len([]rune(string)) with runtime.countrunes(string).
return mkcall("countrunes", n.Type(), init, typecheck.Conv(n.X.(*ir.ConvExpr).X, types.Types[types.TSTRING]))
}
n.X = walkExpr(n.X, init)
// replace len(*[10]int) with 10.
// delayed until now to preserve side effects.
t := n.X.Type()
if t.IsPtr() {
t = t.Elem()
}
if t.IsArray() {
safeExpr(n.X, init)
con := typecheck.OrigInt(n, t.NumElem())
con.SetTypecheck(1)
return con
}
return n
}
// walkMakeChan walks an OMAKECHAN node.
func walkMakeChan(n *ir.MakeExpr, init *ir.Nodes) ir.Node {
// When size fits into int, use makechan instead of
// makechan64, which is faster and shorter on 32 bit platforms.
size := n.Len
fnname := "makechan64"
argtype := types.Types[types.TINT64]
// Type checking guarantees that TIDEAL size is positive and fits in an int.
// The case of size overflow when converting TUINT or TUINTPTR to TINT
// will be handled by the negative range checks in makechan during runtime.
if size.Type().IsKind(types.TIDEAL) || size.Type().Size() <= types.Types[types.TUINT].Size() {
fnname = "makechan"
argtype = types.Types[types.TINT]
}
return mkcall1(chanfn(fnname, 1, n.Type()), n.Type(), init, reflectdata.TypePtr(n.Type()), typecheck.Conv(size, argtype))
}
// walkMakeMap walks an OMAKEMAP node.
func walkMakeMap(n *ir.MakeExpr, init *ir.Nodes) ir.Node {
t := n.Type()
hmapType := reflectdata.MapType(t)
hint := n.Len
// var h *hmap
var h ir.Node
if n.Esc() == ir.EscNone {
// Allocate hmap on stack.
// var hv hmap
// h = &hv
h = stackTempAddr(init, hmapType)
// Allocate one bucket pointed to by hmap.buckets on stack if hint
// is not larger than BUCKETSIZE. In case hint is larger than
// BUCKETSIZE runtime.makemap will allocate the buckets on the heap.
// Maximum key and elem size is 128 bytes, larger objects
// are stored with an indirection. So max bucket size is 2048+eps.
if !ir.IsConst(hint, constant.Int) ||
constant.Compare(hint.Val(), token.LEQ, constant.MakeInt64(reflectdata.BUCKETSIZE)) {
// In case hint is larger than BUCKETSIZE runtime.makemap
// will allocate the buckets on the heap, see #20184
//
// if hint <= BUCKETSIZE {
// var bv bmap
// b = &bv
// h.buckets = b
// }
nif := ir.NewIfStmt(base.Pos, ir.NewBinaryExpr(base.Pos, ir.OLE, hint, ir.NewInt(reflectdata.BUCKETSIZE)), nil, nil)
nif.Likely = true
// var bv bmap
// b = &bv
b := stackTempAddr(&nif.Body, reflectdata.MapBucketType(t))
// h.buckets = b
bsym := hmapType.Field(5).Sym // hmap.buckets see reflect.go:hmap
na := ir.NewAssignStmt(base.Pos, ir.NewSelectorExpr(base.Pos, ir.ODOT, h, bsym), b)
nif.Body.Append(na)
appendWalkStmt(init, nif)
}
}
if ir.IsConst(hint, constant.Int) && constant.Compare(hint.Val(), token.LEQ, constant.MakeInt64(reflectdata.BUCKETSIZE)) {
// Handling make(map[any]any) and
// make(map[any]any, hint) where hint <= BUCKETSIZE
// special allows for faster map initialization and
// improves binary size by using calls with fewer arguments.
// For hint <= BUCKETSIZE overLoadFactor(hint, 0) is false
// and no buckets will be allocated by makemap. Therefore,
// no buckets need to be allocated in this code path.
if n.Esc() == ir.EscNone {
// Only need to initialize h.hash0 since
// hmap h has been allocated on the stack already.
// h.hash0 = fastrand()
rand := mkcall("fastrand", types.Types[types.TUINT32], init)
hashsym := hmapType.Field(4).Sym // hmap.hash0 see reflect.go:hmap
appendWalkStmt(init, ir.NewAssignStmt(base.Pos, ir.NewSelectorExpr(base.Pos, ir.ODOT, h, hashsym), rand))
return typecheck.ConvNop(h, t)
}
// Call runtime.makehmap to allocate an
// hmap on the heap and initialize hmap's hash0 field.
fn := typecheck.LookupRuntime("makemap_small")
fn = typecheck.SubstArgTypes(fn, t.Key(), t.Elem())
return mkcall1(fn, n.Type(), init)
}
if n.Esc() != ir.EscNone {
h = typecheck.NodNil()
}
// Map initialization with a variable or large hint is
// more complicated. We therefore generate a call to
// runtime.makemap to initialize hmap and allocate the
// map buckets.
// When hint fits into int, use makemap instead of
// makemap64, which is faster and shorter on 32 bit platforms.
fnname := "makemap64"
argtype := types.Types[types.TINT64]
// Type checking guarantees that TIDEAL hint is positive and fits in an int.
// See checkmake call in TMAP case of OMAKE case in OpSwitch in typecheck1 function.
// The case of hint overflow when converting TUINT or TUINTPTR to TINT
// will be handled by the negative range checks in makemap during runtime.
if hint.Type().IsKind(types.TIDEAL) || hint.Type().Size() <= types.Types[types.TUINT].Size() {
fnname = "makemap"
argtype = types.Types[types.TINT]
}
fn := typecheck.LookupRuntime(fnname)
fn = typecheck.SubstArgTypes(fn, hmapType, t.Key(), t.Elem())
return mkcall1(fn, n.Type(), init, reflectdata.TypePtr(n.Type()), typecheck.Conv(hint, argtype), h)
}
// walkMakeSlice walks an OMAKESLICE node.
func walkMakeSlice(n *ir.MakeExpr, init *ir.Nodes) ir.Node {
l := n.Len
r := n.Cap
if r == nil {
r = safeExpr(l, init)
l = r
}
t := n.Type()
if t.Elem().NotInHeap() {
base.Errorf("%v can't be allocated in Go; it is incomplete (or unallocatable)", t.Elem())
}
if n.Esc() == ir.EscNone {
if why := escape.HeapAllocReason(n); why != "" {
base.Fatalf("%v has EscNone, but %v", n, why)
}
// var arr [r]T
// n = arr[:l]
i := typecheck.IndexConst(r)
if i < 0 {
base.Fatalf("walkExpr: invalid index %v", r)
}
// cap is constrained to [0,2^31) or [0,2^63) depending on whether
// we're in 32-bit or 64-bit systems. So it's safe to do:
//
// if uint64(len) > cap {
// if len < 0 { panicmakeslicelen() }
// panicmakeslicecap()
// }
nif := ir.NewIfStmt(base.Pos, ir.NewBinaryExpr(base.Pos, ir.OGT, typecheck.Conv(l, types.Types[types.TUINT64]), ir.NewInt(i)), nil, nil)
niflen := ir.NewIfStmt(base.Pos, ir.NewBinaryExpr(base.Pos, ir.OLT, l, ir.NewInt(0)), nil, nil)
niflen.Body = []ir.Node{mkcall("panicmakeslicelen", nil, init)}
nif.Body.Append(niflen, mkcall("panicmakeslicecap", nil, init))
init.Append(typecheck.Stmt(nif))
t = types.NewArray(t.Elem(), i) // [r]T
var_ := typecheck.Temp(t)
appendWalkStmt(init, ir.NewAssignStmt(base.Pos, var_, nil)) // zero temp
r := ir.NewSliceExpr(base.Pos, ir.OSLICE, var_, nil, l, nil) // arr[:l]
// The conv is necessary in case n.Type is named.
return walkExpr(typecheck.Expr(typecheck.Conv(r, n.Type())), init)
}
// n escapes; set up a call to makeslice.
// When len and cap can fit into int, use makeslice instead of
// makeslice64, which is faster and shorter on 32 bit platforms.
len, cap := l, r
fnname := "makeslice64"
argtype := types.Types[types.TINT64]
// Type checking guarantees that TIDEAL len/cap are positive and fit in an int.
// The case of len or cap overflow when converting TUINT or TUINTPTR to TINT
// will be handled by the negative range checks in makeslice during runtime.
if (len.Type().IsKind(types.TIDEAL) || len.Type().Size() <= types.Types[types.TUINT].Size()) &&
(cap.Type().IsKind(types.TIDEAL) || cap.Type().Size() <= types.Types[types.TUINT].Size()) {
fnname = "makeslice"
argtype = types.Types[types.TINT]
}
fn := typecheck.LookupRuntime(fnname)
ptr := mkcall1(fn, types.Types[types.TUNSAFEPTR], init, reflectdata.TypePtr(t.Elem()), typecheck.Conv(len, argtype), typecheck.Conv(cap, argtype))
ptr.MarkNonNil()
len = typecheck.Conv(len, types.Types[types.TINT])
cap = typecheck.Conv(cap, types.Types[types.TINT])
sh := ir.NewSliceHeaderExpr(base.Pos, t, ptr, len, cap)
return walkExpr(typecheck.Expr(sh), init)
}
// walkMakeSliceCopy walks an OMAKESLICECOPY node.
func walkMakeSliceCopy(n *ir.MakeExpr, init *ir.Nodes) ir.Node {
if n.Esc() == ir.EscNone {
base.Fatalf("OMAKESLICECOPY with EscNone: %v", n)
}
t := n.Type()
if t.Elem().NotInHeap() {
base.Errorf("%v can't be allocated in Go; it is incomplete (or unallocatable)", t.Elem())
}
length := typecheck.Conv(n.Len, types.Types[types.TINT])
copylen := ir.NewUnaryExpr(base.Pos, ir.OLEN, n.Cap)
copyptr := ir.NewUnaryExpr(base.Pos, ir.OSPTR, n.Cap)
if !t.Elem().HasPointers() && n.Bounded() {
// When len(to)==len(from) and elements have no pointers:
// replace make+copy with runtime.mallocgc+runtime.memmove.
// We do not check for overflow of len(to)*elem.Width here
// since len(from) is an existing checked slice capacity
// with same elem.Width for the from slice.
size := ir.NewBinaryExpr(base.Pos, ir.OMUL, typecheck.Conv(length, types.Types[types.TUINTPTR]), typecheck.Conv(ir.NewInt(t.Elem().Size()), types.Types[types.TUINTPTR]))
// instantiate mallocgc(size uintptr, typ *byte, needszero bool) unsafe.Pointer
fn := typecheck.LookupRuntime("mallocgc")
ptr := mkcall1(fn, types.Types[types.TUNSAFEPTR], init, size, typecheck.NodNil(), ir.NewBool(false))
ptr.MarkNonNil()
sh := ir.NewSliceHeaderExpr(base.Pos, t, ptr, length, length)
s := typecheck.Temp(t)
r := typecheck.Stmt(ir.NewAssignStmt(base.Pos, s, sh))
r = walkExpr(r, init)
init.Append(r)
// instantiate memmove(to *any, frm *any, size uintptr)
fn = typecheck.LookupRuntime("memmove")
fn = typecheck.SubstArgTypes(fn, t.Elem(), t.Elem())
ncopy := mkcall1(fn, nil, init, ir.NewUnaryExpr(base.Pos, ir.OSPTR, s), copyptr, size)
init.Append(walkExpr(typecheck.Stmt(ncopy), init))
return s
}
// Replace make+copy with runtime.makeslicecopy.
// instantiate makeslicecopy(typ *byte, tolen int, fromlen int, from unsafe.Pointer) unsafe.Pointer
fn := typecheck.LookupRuntime("makeslicecopy")
ptr := mkcall1(fn, types.Types[types.TUNSAFEPTR], init, reflectdata.TypePtr(t.Elem()), length, copylen, typecheck.Conv(copyptr, types.Types[types.TUNSAFEPTR]))
ptr.MarkNonNil()
sh := ir.NewSliceHeaderExpr(base.Pos, t, ptr, length, length)
return walkExpr(typecheck.Expr(sh), init)
}
// walkNew walks an ONEW node.
func walkNew(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
t := n.Type().Elem()
if t.NotInHeap() {
base.Errorf("%v can't be allocated in Go; it is incomplete (or unallocatable)", n.Type().Elem())
}
if n.Esc() == ir.EscNone {
if t.Size() > ir.MaxImplicitStackVarSize {
base.Fatalf("large ONEW with EscNone: %v", n)
}
return stackTempAddr(init, t)
}
types.CalcSize(t)
n.MarkNonNil()
return n
}
// generate code for print
func walkPrint(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
// Hoist all the argument evaluation up before the lock.
walkExprListCheap(nn.Args, init)
// For println, add " " between elements and "\n" at the end.
if nn.Op() == ir.OPRINTN {
s := nn.Args
t := make([]ir.Node, 0, len(s)*2)
for i, n := range s {
if i != 0 {
t = append(t, ir.NewString(" "))
}
t = append(t, n)
}
t = append(t, ir.NewString("\n"))
nn.Args = t
}
// Collapse runs of constant strings.
s := nn.Args
t := make([]ir.Node, 0, len(s))
for i := 0; i < len(s); {
var strs []string
for i < len(s) && ir.IsConst(s[i], constant.String) {
strs = append(strs, ir.StringVal(s[i]))
i++
}
if len(strs) > 0 {
t = append(t, ir.NewString(strings.Join(strs, "")))
}
if i < len(s) {
t = append(t, s[i])
i++
}
}
nn.Args = t
calls := []ir.Node{mkcall("printlock", nil, init)}
for i, n := range nn.Args {
if n.Op() == ir.OLITERAL {
if n.Type() == types.UntypedRune {
n = typecheck.DefaultLit(n, types.RuneType)
}
switch n.Val().Kind() {
case constant.Int:
n = typecheck.DefaultLit(n, types.Types[types.TINT64])
case constant.Float:
n = typecheck.DefaultLit(n, types.Types[types.TFLOAT64])
}
}
if n.Op() != ir.OLITERAL && n.Type() != nil && n.Type().Kind() == types.TIDEAL {
n = typecheck.DefaultLit(n, types.Types[types.TINT64])
}
n = typecheck.DefaultLit(n, nil)
nn.Args[i] = n
if n.Type() == nil || n.Type().Kind() == types.TFORW {
continue
}
var on *ir.Name
switch n.Type().Kind() {
case types.TINTER:
if n.Type().IsEmptyInterface() {
on = typecheck.LookupRuntime("printeface")
} else {
on = typecheck.LookupRuntime("printiface")
}
on = typecheck.SubstArgTypes(on, n.Type()) // any-1
case types.TPTR:
if n.Type().Elem().NotInHeap() {
on = typecheck.LookupRuntime("printuintptr")
n = ir.NewConvExpr(base.Pos, ir.OCONV, nil, n)
n.SetType(types.Types[types.TUNSAFEPTR])
n = ir.NewConvExpr(base.Pos, ir.OCONV, nil, n)
n.SetType(types.Types[types.TUINTPTR])
break
}
fallthrough
case types.TCHAN, types.TMAP, types.TFUNC, types.TUNSAFEPTR:
on = typecheck.LookupRuntime("printpointer")
on = typecheck.SubstArgTypes(on, n.Type()) // any-1
case types.TSLICE:
on = typecheck.LookupRuntime("printslice")
on = typecheck.SubstArgTypes(on, n.Type()) // any-1
case types.TUINT, types.TUINT8, types.TUINT16, types.TUINT32, types.TUINT64, types.TUINTPTR:
if types.IsRuntimePkg(n.Type().Sym().Pkg) && n.Type().Sym().Name == "hex" {
on = typecheck.LookupRuntime("printhex")
} else {
on = typecheck.LookupRuntime("printuint")
}
case types.TINT, types.TINT8, types.TINT16, types.TINT32, types.TINT64:
on = typecheck.LookupRuntime("printint")
case types.TFLOAT32, types.TFLOAT64:
on = typecheck.LookupRuntime("printfloat")
case types.TCOMPLEX64, types.TCOMPLEX128:
on = typecheck.LookupRuntime("printcomplex")
case types.TBOOL:
on = typecheck.LookupRuntime("printbool")
case types.TSTRING:
cs := ""
if ir.IsConst(n, constant.String) {
cs = ir.StringVal(n)
}
switch cs {
case " ":
on = typecheck.LookupRuntime("printsp")
case "\n":
on = typecheck.LookupRuntime("printnl")
default:
on = typecheck.LookupRuntime("printstring")
}
default:
badtype(ir.OPRINT, n.Type(), nil)
continue
}
r := ir.NewCallExpr(base.Pos, ir.OCALL, on, nil)
if params := on.Type().Params().FieldSlice(); len(params) > 0 {
t := params[0].Type
n = typecheck.Conv(n, t)
r.Args.Append(n)
}
calls = append(calls, r)
}
calls = append(calls, mkcall("printunlock", nil, init))
typecheck.Stmts(calls)
walkExprList(calls, init)
r := ir.NewBlockStmt(base.Pos, nil)
r.List = calls
return walkStmt(typecheck.Stmt(r))
}
// walkRecover walks an ORECOVERFP node.
func walkRecoverFP(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
return mkcall("gorecover", nn.Type(), init, walkExpr(nn.Args[0], init))
}
func walkUnsafeSlice(n *ir.BinaryExpr, init *ir.Nodes) ir.Node {
ptr := safeExpr(n.X, init)
len := safeExpr(n.Y, init)
sliceType := n.Type()
lenType := types.Types[types.TINT64]
unsafePtr := typecheck.Conv(ptr, types.Types[types.TUNSAFEPTR])
// If checkptr enabled, call runtime.unsafeslicecheckptr to check ptr and len.
// for simplicity, unsafeslicecheckptr always uses int64.
// Type checking guarantees that TIDEAL len/cap are positive and fit in an int.
// The case of len or cap overflow when converting TUINT or TUINTPTR to TINT
// will be handled by the negative range checks in unsafeslice during runtime.
if ir.ShouldCheckPtr(ir.CurFunc, 1) {
fnname := "unsafeslicecheckptr"
fn := typecheck.LookupRuntime(fnname)
init.Append(mkcall1(fn, nil, init, reflectdata.TypePtr(sliceType.Elem()), unsafePtr, typecheck.Conv(len, lenType)))
} else {
// Otherwise, open code unsafe.Slice to prevent runtime call overhead.
// Keep this code in sync with runtime.unsafeslice{,64}
if len.Type().IsKind(types.TIDEAL) || len.Type().Size() <= types.Types[types.TUINT].Size() {
lenType = types.Types[types.TINT]
} else {
// len64 := int64(len)
// if int64(int(len64)) != len64 {
// panicunsafeslicelen()
// }
len64 := typecheck.Conv(len, lenType)
nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
nif.Cond = ir.NewBinaryExpr(base.Pos, ir.ONE, typecheck.Conv(typecheck.Conv(len64, types.Types[types.TINT]), lenType), len64)
nif.Body.Append(mkcall("panicunsafeslicelen", nil, &nif.Body))
appendWalkStmt(init, nif)
}
// if len < 0 { panicunsafeslicelen() }
nif := ir.NewIfStmt(base.Pos, nil, nil, nil)
nif.Cond = ir.NewBinaryExpr(base.Pos, ir.OLT, typecheck.Conv(len, lenType), ir.NewInt(0))
nif.Body.Append(mkcall("panicunsafeslicelen", nil, &nif.Body))
appendWalkStmt(init, nif)
// mem, overflow := runtime.mulUintptr(et.size, len)
mem := typecheck.Temp(types.Types[types.TUINTPTR])
overflow := typecheck.Temp(types.Types[types.TBOOL])
fn := typecheck.LookupRuntime("mulUintptr")
call := mkcall1(fn, fn.Type().Results(), init, ir.NewInt(sliceType.Elem().Size()), typecheck.Conv(typecheck.Conv(len, lenType), types.Types[types.TUINTPTR]))
appendWalkStmt(init, ir.NewAssignListStmt(base.Pos, ir.OAS2, []ir.Node{mem, overflow}, []ir.Node{call}))
// if overflow || mem > -uintptr(ptr) {
// if ptr == nil {
// panicunsafesliceptrnil()
// }
// panicunsafeslicelen()
// }
nif = ir.NewIfStmt(base.Pos, nil, nil, nil)
memCond := ir.NewBinaryExpr(base.Pos, ir.OGT, mem, ir.NewUnaryExpr(base.Pos, ir.ONEG, typecheck.Conv(unsafePtr, types.Types[types.TUINTPTR])))
nif.Cond = ir.NewLogicalExpr(base.Pos, ir.OOROR, overflow, memCond)
nifPtr := ir.NewIfStmt(base.Pos, nil, nil, nil)
nifPtr.Cond = ir.NewBinaryExpr(base.Pos, ir.OEQ, unsafePtr, typecheck.NodNil())
nifPtr.Body.Append(mkcall("panicunsafeslicenilptr", nil, &nifPtr.Body))
nif.Body.Append(nifPtr, mkcall("panicunsafeslicelen", nil, &nif.Body))
appendWalkStmt(init, nif)
}
h := ir.NewSliceHeaderExpr(n.Pos(), sliceType,
typecheck.Conv(ptr, types.Types[types.TUNSAFEPTR]),
typecheck.Conv(len, types.Types[types.TINT]),
typecheck.Conv(len, types.Types[types.TINT]))
return walkExpr(typecheck.Expr(h), init)
}
func badtype(op ir.Op, tl, tr *types.Type) {
var s string
if tl != nil {
s += fmt.Sprintf("\n\t%v", tl)
}
if tr != nil {
s += fmt.Sprintf("\n\t%v", tr)
}
// common mistake: *struct and *interface.
if tl != nil && tr != nil && tl.IsPtr() && tr.IsPtr() {
if tl.Elem().IsStruct() && tr.Elem().IsInterface() {
s += "\n\t(*struct vs *interface)"
} else if tl.Elem().IsInterface() && tr.Elem().IsStruct() {
s += "\n\t(*interface vs *struct)"
}
}
base.Errorf("illegal types for operand: %v%s", op, s)
}
func writebarrierfn(name string, l *types.Type, r *types.Type) ir.Node {
fn := typecheck.LookupRuntime(name)
fn = typecheck.SubstArgTypes(fn, l, r)
return fn
}
// isRuneCount reports whether n is of the form len([]rune(string)).
// These are optimized into a call to runtime.countrunes.
func isRuneCount(n ir.Node) bool {
return base.Flag.N == 0 && !base.Flag.Cfg.Instrumenting && n.Op() == ir.OLEN && n.(*ir.UnaryExpr).X.Op() == ir.OSTR2RUNES
}
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