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-rw-r--r--src/cmd/compile/internal/walk/expr.go1033
1 files changed, 1033 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/walk/expr.go b/src/cmd/compile/internal/walk/expr.go
new file mode 100644
index 0000000..24fe0d0
--- /dev/null
+++ b/src/cmd/compile/internal/walk/expr.go
@@ -0,0 +1,1033 @@
+// 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"
+ "internal/buildcfg"
+ "strings"
+
+ "cmd/compile/internal/base"
+ "cmd/compile/internal/ir"
+ "cmd/compile/internal/reflectdata"
+ "cmd/compile/internal/staticdata"
+ "cmd/compile/internal/typecheck"
+ "cmd/compile/internal/types"
+ "cmd/internal/obj"
+)
+
+// The result of walkExpr MUST be assigned back to n, e.g.
+//
+// n.Left = walkExpr(n.Left, init)
+func walkExpr(n ir.Node, init *ir.Nodes) ir.Node {
+ if n == nil {
+ return n
+ }
+
+ if n, ok := n.(ir.InitNode); ok && init == n.PtrInit() {
+ // not okay to use n->ninit when walking n,
+ // because we might replace n with some other node
+ // and would lose the init list.
+ base.Fatalf("walkExpr init == &n->ninit")
+ }
+
+ if len(n.Init()) != 0 {
+ walkStmtList(n.Init())
+ init.Append(ir.TakeInit(n)...)
+ }
+
+ lno := ir.SetPos(n)
+
+ if base.Flag.LowerW > 1 {
+ ir.Dump("before walk expr", n)
+ }
+
+ if n.Typecheck() != 1 {
+ base.Fatalf("missed typecheck: %+v", n)
+ }
+
+ if n.Type().IsUntyped() {
+ base.Fatalf("expression has untyped type: %+v", n)
+ }
+
+ n = walkExpr1(n, init)
+
+ // Eagerly compute sizes of all expressions for the back end.
+ if typ := n.Type(); typ != nil && typ.Kind() != types.TBLANK && !typ.IsFuncArgStruct() {
+ types.CheckSize(typ)
+ }
+ if n, ok := n.(*ir.Name); ok && n.Heapaddr != nil {
+ types.CheckSize(n.Heapaddr.Type())
+ }
+ if ir.IsConst(n, constant.String) {
+ // Emit string symbol now to avoid emitting
+ // any concurrently during the backend.
+ _ = staticdata.StringSym(n.Pos(), constant.StringVal(n.Val()))
+ }
+
+ if base.Flag.LowerW != 0 && n != nil {
+ ir.Dump("after walk expr", n)
+ }
+
+ base.Pos = lno
+ return n
+}
+
+func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
+ switch n.Op() {
+ default:
+ ir.Dump("walk", n)
+ base.Fatalf("walkExpr: switch 1 unknown op %+v", n.Op())
+ panic("unreachable")
+
+ case ir.OGETG, ir.OGETCALLERPC, ir.OGETCALLERSP:
+ return n
+
+ case ir.OTYPE, ir.ONAME, ir.OLITERAL, ir.ONIL, ir.OLINKSYMOFFSET:
+ // TODO(mdempsky): Just return n; see discussion on CL 38655.
+ // Perhaps refactor to use Node.mayBeShared for these instead.
+ // If these return early, make sure to still call
+ // StringSym for constant strings.
+ return n
+
+ case ir.OMETHEXPR:
+ // TODO(mdempsky): Do this right after type checking.
+ n := n.(*ir.SelectorExpr)
+ return n.FuncName()
+
+ case ir.ONOT, ir.ONEG, ir.OPLUS, ir.OBITNOT, ir.OREAL, ir.OIMAG, ir.OSPTR, ir.OITAB, ir.OIDATA:
+ n := n.(*ir.UnaryExpr)
+ n.X = walkExpr(n.X, init)
+ return n
+
+ case ir.ODOTMETH, ir.ODOTINTER:
+ n := n.(*ir.SelectorExpr)
+ n.X = walkExpr(n.X, init)
+ return n
+
+ case ir.OADDR:
+ n := n.(*ir.AddrExpr)
+ n.X = walkExpr(n.X, init)
+ return n
+
+ case ir.ODEREF:
+ n := n.(*ir.StarExpr)
+ n.X = walkExpr(n.X, init)
+ return n
+
+ case ir.OEFACE, ir.OAND, ir.OANDNOT, ir.OSUB, ir.OMUL, ir.OADD, ir.OOR, ir.OXOR, ir.OLSH, ir.ORSH,
+ ir.OUNSAFEADD:
+ n := n.(*ir.BinaryExpr)
+ n.X = walkExpr(n.X, init)
+ n.Y = walkExpr(n.Y, init)
+ return n
+
+ case ir.OUNSAFESLICE:
+ n := n.(*ir.BinaryExpr)
+ return walkUnsafeSlice(n, init)
+
+ case ir.OUNSAFESTRING:
+ n := n.(*ir.BinaryExpr)
+ return walkUnsafeString(n, init)
+
+ case ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
+ n := n.(*ir.UnaryExpr)
+ return walkUnsafeData(n, init)
+
+ case ir.ODOT, ir.ODOTPTR:
+ n := n.(*ir.SelectorExpr)
+ return walkDot(n, init)
+
+ case ir.ODOTTYPE, ir.ODOTTYPE2:
+ n := n.(*ir.TypeAssertExpr)
+ return walkDotType(n, init)
+
+ case ir.ODYNAMICDOTTYPE, ir.ODYNAMICDOTTYPE2:
+ n := n.(*ir.DynamicTypeAssertExpr)
+ return walkDynamicDotType(n, init)
+
+ case ir.OLEN, ir.OCAP:
+ n := n.(*ir.UnaryExpr)
+ return walkLenCap(n, init)
+
+ case ir.OCOMPLEX:
+ n := n.(*ir.BinaryExpr)
+ n.X = walkExpr(n.X, init)
+ n.Y = walkExpr(n.Y, init)
+ return n
+
+ case ir.OEQ, ir.ONE, ir.OLT, ir.OLE, ir.OGT, ir.OGE:
+ n := n.(*ir.BinaryExpr)
+ return walkCompare(n, init)
+
+ case ir.OANDAND, ir.OOROR:
+ n := n.(*ir.LogicalExpr)
+ return walkLogical(n, init)
+
+ case ir.OPRINT, ir.OPRINTN:
+ return walkPrint(n.(*ir.CallExpr), init)
+
+ case ir.OPANIC:
+ n := n.(*ir.UnaryExpr)
+ return mkcall("gopanic", nil, init, n.X)
+
+ case ir.ORECOVERFP:
+ return walkRecoverFP(n.(*ir.CallExpr), init)
+
+ case ir.OCFUNC:
+ return n
+
+ case ir.OCALLINTER, ir.OCALLFUNC:
+ n := n.(*ir.CallExpr)
+ return walkCall(n, init)
+
+ case ir.OAS, ir.OASOP:
+ return walkAssign(init, n)
+
+ case ir.OAS2:
+ n := n.(*ir.AssignListStmt)
+ return walkAssignList(init, n)
+
+ // a,b,... = fn()
+ case ir.OAS2FUNC:
+ n := n.(*ir.AssignListStmt)
+ return walkAssignFunc(init, n)
+
+ // x, y = <-c
+ // order.stmt made sure x is addressable or blank.
+ case ir.OAS2RECV:
+ n := n.(*ir.AssignListStmt)
+ return walkAssignRecv(init, n)
+
+ // a,b = m[i]
+ case ir.OAS2MAPR:
+ n := n.(*ir.AssignListStmt)
+ return walkAssignMapRead(init, n)
+
+ case ir.ODELETE:
+ n := n.(*ir.CallExpr)
+ return walkDelete(init, n)
+
+ case ir.OAS2DOTTYPE:
+ n := n.(*ir.AssignListStmt)
+ return walkAssignDotType(n, init)
+
+ case ir.OCONVIFACE:
+ n := n.(*ir.ConvExpr)
+ return walkConvInterface(n, init)
+
+ case ir.OCONVIDATA:
+ n := n.(*ir.ConvExpr)
+ return walkConvIData(n, init)
+
+ case ir.OCONV, ir.OCONVNOP:
+ n := n.(*ir.ConvExpr)
+ return walkConv(n, init)
+
+ case ir.OSLICE2ARR:
+ n := n.(*ir.ConvExpr)
+ return walkSliceToArray(n, init)
+
+ case ir.OSLICE2ARRPTR:
+ n := n.(*ir.ConvExpr)
+ n.X = walkExpr(n.X, init)
+ return n
+
+ case ir.ODIV, ir.OMOD:
+ n := n.(*ir.BinaryExpr)
+ return walkDivMod(n, init)
+
+ case ir.OINDEX:
+ n := n.(*ir.IndexExpr)
+ return walkIndex(n, init)
+
+ case ir.OINDEXMAP:
+ n := n.(*ir.IndexExpr)
+ return walkIndexMap(n, init)
+
+ case ir.ORECV:
+ base.Fatalf("walkExpr ORECV") // should see inside OAS only
+ panic("unreachable")
+
+ case ir.OSLICEHEADER:
+ n := n.(*ir.SliceHeaderExpr)
+ return walkSliceHeader(n, init)
+
+ case ir.OSTRINGHEADER:
+ n := n.(*ir.StringHeaderExpr)
+ return walkStringHeader(n, init)
+
+ case ir.OSLICE, ir.OSLICEARR, ir.OSLICESTR, ir.OSLICE3, ir.OSLICE3ARR:
+ n := n.(*ir.SliceExpr)
+ return walkSlice(n, init)
+
+ case ir.ONEW:
+ n := n.(*ir.UnaryExpr)
+ return walkNew(n, init)
+
+ case ir.OADDSTR:
+ return walkAddString(n.(*ir.AddStringExpr), init)
+
+ case ir.OAPPEND:
+ // order should make sure we only see OAS(node, OAPPEND), which we handle above.
+ base.Fatalf("append outside assignment")
+ panic("unreachable")
+
+ case ir.OCOPY:
+ return walkCopy(n.(*ir.BinaryExpr), init, base.Flag.Cfg.Instrumenting && !base.Flag.CompilingRuntime)
+
+ case ir.OCLOSE:
+ n := n.(*ir.UnaryExpr)
+ return walkClose(n, init)
+
+ case ir.OMAKECHAN:
+ n := n.(*ir.MakeExpr)
+ return walkMakeChan(n, init)
+
+ case ir.OMAKEMAP:
+ n := n.(*ir.MakeExpr)
+ return walkMakeMap(n, init)
+
+ case ir.OMAKESLICE:
+ n := n.(*ir.MakeExpr)
+ return walkMakeSlice(n, init)
+
+ case ir.OMAKESLICECOPY:
+ n := n.(*ir.MakeExpr)
+ return walkMakeSliceCopy(n, init)
+
+ case ir.ORUNESTR:
+ n := n.(*ir.ConvExpr)
+ return walkRuneToString(n, init)
+
+ case ir.OBYTES2STR, ir.ORUNES2STR:
+ n := n.(*ir.ConvExpr)
+ return walkBytesRunesToString(n, init)
+
+ case ir.OBYTES2STRTMP:
+ n := n.(*ir.ConvExpr)
+ return walkBytesToStringTemp(n, init)
+
+ case ir.OSTR2BYTES:
+ n := n.(*ir.ConvExpr)
+ return walkStringToBytes(n, init)
+
+ case ir.OSTR2BYTESTMP:
+ n := n.(*ir.ConvExpr)
+ return walkStringToBytesTemp(n, init)
+
+ case ir.OSTR2RUNES:
+ n := n.(*ir.ConvExpr)
+ return walkStringToRunes(n, init)
+
+ case ir.OARRAYLIT, ir.OSLICELIT, ir.OMAPLIT, ir.OSTRUCTLIT, ir.OPTRLIT:
+ return walkCompLit(n, init)
+
+ case ir.OSEND:
+ n := n.(*ir.SendStmt)
+ return walkSend(n, init)
+
+ case ir.OCLOSURE:
+ return walkClosure(n.(*ir.ClosureExpr), init)
+
+ case ir.OMETHVALUE:
+ return walkMethodValue(n.(*ir.SelectorExpr), init)
+ }
+
+ // No return! Each case must return (or panic),
+ // to avoid confusion about what gets returned
+ // in the presence of type assertions.
+}
+
+// walk the whole tree of the body of an
+// expression or simple statement.
+// the types expressions are calculated.
+// compile-time constants are evaluated.
+// complex side effects like statements are appended to init.
+func walkExprList(s []ir.Node, init *ir.Nodes) {
+ for i := range s {
+ s[i] = walkExpr(s[i], init)
+ }
+}
+
+func walkExprListCheap(s []ir.Node, init *ir.Nodes) {
+ for i, n := range s {
+ s[i] = cheapExpr(n, init)
+ s[i] = walkExpr(s[i], init)
+ }
+}
+
+func walkExprListSafe(s []ir.Node, init *ir.Nodes) {
+ for i, n := range s {
+ s[i] = safeExpr(n, init)
+ s[i] = walkExpr(s[i], init)
+ }
+}
+
+// return side-effect free and cheap n, appending side effects to init.
+// result may not be assignable.
+func cheapExpr(n ir.Node, init *ir.Nodes) ir.Node {
+ switch n.Op() {
+ case ir.ONAME, ir.OLITERAL, ir.ONIL:
+ return n
+ }
+
+ return copyExpr(n, n.Type(), init)
+}
+
+// return side effect-free n, appending side effects to init.
+// result is assignable if n is.
+func safeExpr(n ir.Node, init *ir.Nodes) ir.Node {
+ if n == nil {
+ return nil
+ }
+
+ if len(n.Init()) != 0 {
+ walkStmtList(n.Init())
+ init.Append(ir.TakeInit(n)...)
+ }
+
+ switch n.Op() {
+ case ir.ONAME, ir.OLITERAL, ir.ONIL, ir.OLINKSYMOFFSET:
+ return n
+
+ case ir.OLEN, ir.OCAP:
+ n := n.(*ir.UnaryExpr)
+ l := safeExpr(n.X, init)
+ if l == n.X {
+ return n
+ }
+ a := ir.Copy(n).(*ir.UnaryExpr)
+ a.X = l
+ return walkExpr(typecheck.Expr(a), init)
+
+ case ir.ODOT, ir.ODOTPTR:
+ n := n.(*ir.SelectorExpr)
+ l := safeExpr(n.X, init)
+ if l == n.X {
+ return n
+ }
+ a := ir.Copy(n).(*ir.SelectorExpr)
+ a.X = l
+ return walkExpr(typecheck.Expr(a), init)
+
+ case ir.ODEREF:
+ n := n.(*ir.StarExpr)
+ l := safeExpr(n.X, init)
+ if l == n.X {
+ return n
+ }
+ a := ir.Copy(n).(*ir.StarExpr)
+ a.X = l
+ return walkExpr(typecheck.Expr(a), init)
+
+ case ir.OINDEX, ir.OINDEXMAP:
+ n := n.(*ir.IndexExpr)
+ l := safeExpr(n.X, init)
+ r := safeExpr(n.Index, init)
+ if l == n.X && r == n.Index {
+ return n
+ }
+ a := ir.Copy(n).(*ir.IndexExpr)
+ a.X = l
+ a.Index = r
+ return walkExpr(typecheck.Expr(a), init)
+
+ case ir.OSTRUCTLIT, ir.OARRAYLIT, ir.OSLICELIT:
+ n := n.(*ir.CompLitExpr)
+ if isStaticCompositeLiteral(n) {
+ return n
+ }
+ }
+
+ // make a copy; must not be used as an lvalue
+ if ir.IsAddressable(n) {
+ base.Fatalf("missing lvalue case in safeExpr: %v", n)
+ }
+ return cheapExpr(n, init)
+}
+
+func copyExpr(n ir.Node, t *types.Type, init *ir.Nodes) ir.Node {
+ l := typecheck.Temp(t)
+ appendWalkStmt(init, ir.NewAssignStmt(base.Pos, l, n))
+ return l
+}
+
+func walkAddString(n *ir.AddStringExpr, init *ir.Nodes) ir.Node {
+ c := len(n.List)
+
+ if c < 2 {
+ base.Fatalf("walkAddString count %d too small", c)
+ }
+
+ buf := typecheck.NodNil()
+ if n.Esc() == ir.EscNone {
+ sz := int64(0)
+ for _, n1 := range n.List {
+ if n1.Op() == ir.OLITERAL {
+ sz += int64(len(ir.StringVal(n1)))
+ }
+ }
+
+ // Don't allocate the buffer if the result won't fit.
+ if sz < tmpstringbufsize {
+ // Create temporary buffer for result string on stack.
+ buf = stackBufAddr(tmpstringbufsize, types.Types[types.TUINT8])
+ }
+ }
+
+ // build list of string arguments
+ args := []ir.Node{buf}
+ for _, n2 := range n.List {
+ args = append(args, typecheck.Conv(n2, types.Types[types.TSTRING]))
+ }
+
+ var fn string
+ if c <= 5 {
+ // small numbers of strings use direct runtime helpers.
+ // note: order.expr knows this cutoff too.
+ fn = fmt.Sprintf("concatstring%d", c)
+ } else {
+ // large numbers of strings are passed to the runtime as a slice.
+ fn = "concatstrings"
+
+ t := types.NewSlice(types.Types[types.TSTRING])
+ // args[1:] to skip buf arg
+ slice := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, t, args[1:])
+ slice.Prealloc = n.Prealloc
+ args = []ir.Node{buf, slice}
+ slice.SetEsc(ir.EscNone)
+ }
+
+ cat := typecheck.LookupRuntime(fn)
+ r := ir.NewCallExpr(base.Pos, ir.OCALL, cat, nil)
+ r.Args = args
+ r1 := typecheck.Expr(r)
+ r1 = walkExpr(r1, init)
+ r1.SetType(n.Type())
+
+ return r1
+}
+
+type hookInfo struct {
+ paramType types.Kind
+ argsNum int
+ runtimeFunc string
+}
+
+var hooks = map[string]hookInfo{
+ "strings.EqualFold": {paramType: types.TSTRING, argsNum: 2, runtimeFunc: "libfuzzerHookEqualFold"},
+}
+
+// walkCall walks an OCALLFUNC or OCALLINTER node.
+func walkCall(n *ir.CallExpr, init *ir.Nodes) ir.Node {
+ if n.Op() == ir.OCALLMETH {
+ base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
+ }
+ if n.Op() == ir.OCALLINTER || n.X.Op() == ir.OMETHEXPR {
+ // We expect both interface call reflect.Type.Method and concrete
+ // call reflect.(*rtype).Method.
+ usemethod(n)
+ }
+ if n.Op() == ir.OCALLINTER {
+ reflectdata.MarkUsedIfaceMethod(n)
+ }
+
+ if n.Op() == ir.OCALLFUNC && n.X.Op() == ir.OCLOSURE {
+ directClosureCall(n)
+ }
+
+ if isFuncPCIntrinsic(n) {
+ // For internal/abi.FuncPCABIxxx(fn), if fn is a defined function, rewrite
+ // it to the address of the function of the ABI fn is defined.
+ name := n.X.(*ir.Name).Sym().Name
+ arg := n.Args[0]
+ var wantABI obj.ABI
+ switch name {
+ case "FuncPCABI0":
+ wantABI = obj.ABI0
+ case "FuncPCABIInternal":
+ wantABI = obj.ABIInternal
+ }
+ if isIfaceOfFunc(arg) {
+ fn := arg.(*ir.ConvExpr).X.(*ir.Name)
+ abi := fn.Func.ABI
+ if abi != wantABI {
+ base.ErrorfAt(n.Pos(), "internal/abi.%s expects an %v function, %s is defined as %v", name, wantABI, fn.Sym().Name, abi)
+ }
+ var e ir.Node = ir.NewLinksymExpr(n.Pos(), fn.Sym().LinksymABI(abi), types.Types[types.TUINTPTR])
+ e = ir.NewAddrExpr(n.Pos(), e)
+ e.SetType(types.Types[types.TUINTPTR].PtrTo())
+ return typecheck.Expr(ir.NewConvExpr(n.Pos(), ir.OCONVNOP, n.Type(), e))
+ }
+ // fn is not a defined function. It must be ABIInternal.
+ // Read the address from func value, i.e. *(*uintptr)(idata(fn)).
+ if wantABI != obj.ABIInternal {
+ base.ErrorfAt(n.Pos(), "internal/abi.%s does not accept func expression, which is ABIInternal", name)
+ }
+ arg = walkExpr(arg, init)
+ var e ir.Node = ir.NewUnaryExpr(n.Pos(), ir.OIDATA, arg)
+ e.SetType(n.Type().PtrTo())
+ e.SetTypecheck(1)
+ e = ir.NewStarExpr(n.Pos(), e)
+ e.SetType(n.Type())
+ e.SetTypecheck(1)
+ return e
+ }
+
+ walkCall1(n, init)
+ return n
+}
+
+func walkCall1(n *ir.CallExpr, init *ir.Nodes) {
+ if n.Walked() {
+ return // already walked
+ }
+ n.SetWalked(true)
+
+ if n.Op() == ir.OCALLMETH {
+ base.FatalfAt(n.Pos(), "OCALLMETH missed by typecheck")
+ }
+
+ args := n.Args
+ params := n.X.Type().Params()
+
+ n.X = walkExpr(n.X, init)
+ walkExprList(args, init)
+
+ for i, arg := range args {
+ // Validate argument and parameter types match.
+ param := params.Field(i)
+ if !types.Identical(arg.Type(), param.Type) {
+ base.FatalfAt(n.Pos(), "assigning %L to parameter %v (type %v)", arg, param.Sym, param.Type)
+ }
+
+ // For any argument whose evaluation might require a function call,
+ // store that argument into a temporary variable,
+ // to prevent that calls from clobbering arguments already on the stack.
+ if mayCall(arg) {
+ // assignment of arg to Temp
+ tmp := typecheck.Temp(param.Type)
+ init.Append(convas(typecheck.Stmt(ir.NewAssignStmt(base.Pos, tmp, arg)).(*ir.AssignStmt), init))
+ // replace arg with temp
+ args[i] = tmp
+ }
+ }
+
+ n.Args = args
+ funSym := n.X.Sym()
+ if base.Debug.Libfuzzer != 0 && funSym != nil {
+ if hook, found := hooks[funSym.Pkg.Path+"."+funSym.Name]; found {
+ if len(args) != hook.argsNum {
+ panic(fmt.Sprintf("%s.%s expects %d arguments, but received %d", funSym.Pkg.Path, funSym.Name, hook.argsNum, len(args)))
+ }
+ var hookArgs []ir.Node
+ for _, arg := range args {
+ hookArgs = append(hookArgs, tracecmpArg(arg, types.Types[hook.paramType], init))
+ }
+ hookArgs = append(hookArgs, fakePC(n))
+ init.Append(mkcall(hook.runtimeFunc, nil, init, hookArgs...))
+ }
+ }
+}
+
+// walkDivMod walks an ODIV or OMOD node.
+func walkDivMod(n *ir.BinaryExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+ n.Y = walkExpr(n.Y, init)
+
+ // rewrite complex div into function call.
+ et := n.X.Type().Kind()
+
+ if types.IsComplex[et] && n.Op() == ir.ODIV {
+ t := n.Type()
+ call := mkcall("complex128div", types.Types[types.TCOMPLEX128], init, typecheck.Conv(n.X, types.Types[types.TCOMPLEX128]), typecheck.Conv(n.Y, types.Types[types.TCOMPLEX128]))
+ return typecheck.Conv(call, t)
+ }
+
+ // Nothing to do for float divisions.
+ if types.IsFloat[et] {
+ return n
+ }
+
+ // rewrite 64-bit div and mod on 32-bit architectures.
+ // TODO: Remove this code once we can introduce
+ // runtime calls late in SSA processing.
+ if types.RegSize < 8 && (et == types.TINT64 || et == types.TUINT64) {
+ if n.Y.Op() == ir.OLITERAL {
+ // Leave div/mod by constant powers of 2 or small 16-bit constants.
+ // The SSA backend will handle those.
+ switch et {
+ case types.TINT64:
+ c := ir.Int64Val(n.Y)
+ if c < 0 {
+ c = -c
+ }
+ if c != 0 && c&(c-1) == 0 {
+ return n
+ }
+ case types.TUINT64:
+ c := ir.Uint64Val(n.Y)
+ if c < 1<<16 {
+ return n
+ }
+ if c != 0 && c&(c-1) == 0 {
+ return n
+ }
+ }
+ }
+ var fn string
+ if et == types.TINT64 {
+ fn = "int64"
+ } else {
+ fn = "uint64"
+ }
+ if n.Op() == ir.ODIV {
+ fn += "div"
+ } else {
+ fn += "mod"
+ }
+ return mkcall(fn, n.Type(), init, typecheck.Conv(n.X, types.Types[et]), typecheck.Conv(n.Y, types.Types[et]))
+ }
+ return n
+}
+
+// walkDot walks an ODOT or ODOTPTR node.
+func walkDot(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
+ usefield(n)
+ n.X = walkExpr(n.X, init)
+ return n
+}
+
+// walkDotType walks an ODOTTYPE or ODOTTYPE2 node.
+func walkDotType(n *ir.TypeAssertExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+ // Set up interface type addresses for back end.
+ if !n.Type().IsInterface() && !n.X.Type().IsEmptyInterface() {
+ n.ITab = reflectdata.ITabAddr(n.Type(), n.X.Type())
+ }
+ return n
+}
+
+// walkDynamicDotType walks an ODYNAMICDOTTYPE or ODYNAMICDOTTYPE2 node.
+func walkDynamicDotType(n *ir.DynamicTypeAssertExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+ n.RType = walkExpr(n.RType, init)
+ n.ITab = walkExpr(n.ITab, init)
+ return n
+}
+
+// walkIndex walks an OINDEX node.
+func walkIndex(n *ir.IndexExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+
+ // save the original node for bounds checking elision.
+ // If it was a ODIV/OMOD walk might rewrite it.
+ r := n.Index
+
+ n.Index = walkExpr(n.Index, init)
+
+ // if range of type cannot exceed static array bound,
+ // disable bounds check.
+ if n.Bounded() {
+ return n
+ }
+ t := n.X.Type()
+ if t != nil && t.IsPtr() {
+ t = t.Elem()
+ }
+ if t.IsArray() {
+ n.SetBounded(bounded(r, t.NumElem()))
+ if base.Flag.LowerM != 0 && n.Bounded() && !ir.IsConst(n.Index, constant.Int) {
+ base.Warn("index bounds check elided")
+ }
+ } else if ir.IsConst(n.X, constant.String) {
+ n.SetBounded(bounded(r, int64(len(ir.StringVal(n.X)))))
+ if base.Flag.LowerM != 0 && n.Bounded() && !ir.IsConst(n.Index, constant.Int) {
+ base.Warn("index bounds check elided")
+ }
+ }
+ return n
+}
+
+// mapKeyArg returns an expression for key that is suitable to be passed
+// as the key argument for runtime map* functions.
+// n is is the map indexing or delete Node (to provide Pos).
+func mapKeyArg(fast int, n, key ir.Node, assigned bool) ir.Node {
+ if fast == mapslow {
+ // standard version takes key by reference.
+ // orderState.expr made sure key is addressable.
+ return typecheck.NodAddr(key)
+ }
+ if assigned {
+ // mapassign does distinguish pointer vs. integer key.
+ return key
+ }
+ // mapaccess and mapdelete don't distinguish pointer vs. integer key.
+ switch fast {
+ case mapfast32ptr:
+ return ir.NewConvExpr(n.Pos(), ir.OCONVNOP, types.Types[types.TUINT32], key)
+ case mapfast64ptr:
+ return ir.NewConvExpr(n.Pos(), ir.OCONVNOP, types.Types[types.TUINT64], key)
+ default:
+ // fast version takes key by value.
+ return key
+ }
+}
+
+// walkIndexMap walks an OINDEXMAP node.
+// It replaces m[k] with *map{access1,assign}(maptype, m, &k)
+func walkIndexMap(n *ir.IndexExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+ n.Index = walkExpr(n.Index, init)
+ map_ := n.X
+ t := map_.Type()
+ fast := mapfast(t)
+ key := mapKeyArg(fast, n, n.Index, n.Assigned)
+ args := []ir.Node{reflectdata.IndexMapRType(base.Pos, n), map_, key}
+
+ var mapFn ir.Node
+ switch {
+ case n.Assigned:
+ mapFn = mapfn(mapassign[fast], t, false)
+ case t.Elem().Size() > zeroValSize:
+ args = append(args, reflectdata.ZeroAddr(t.Elem().Size()))
+ mapFn = mapfn("mapaccess1_fat", t, true)
+ default:
+ mapFn = mapfn(mapaccess1[fast], t, false)
+ }
+ call := mkcall1(mapFn, nil, init, args...)
+ call.SetType(types.NewPtr(t.Elem()))
+ call.MarkNonNil() // mapaccess1* and mapassign always return non-nil pointers.
+ star := ir.NewStarExpr(base.Pos, call)
+ star.SetType(t.Elem())
+ star.SetTypecheck(1)
+ return star
+}
+
+// walkLogical walks an OANDAND or OOROR node.
+func walkLogical(n *ir.LogicalExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+
+ // cannot put side effects from n.Right on init,
+ // because they cannot run before n.Left is checked.
+ // save elsewhere and store on the eventual n.Right.
+ var ll ir.Nodes
+
+ n.Y = walkExpr(n.Y, &ll)
+ n.Y = ir.InitExpr(ll, n.Y)
+ return n
+}
+
+// walkSend walks an OSEND node.
+func walkSend(n *ir.SendStmt, init *ir.Nodes) ir.Node {
+ n1 := n.Value
+ n1 = typecheck.AssignConv(n1, n.Chan.Type().Elem(), "chan send")
+ n1 = walkExpr(n1, init)
+ n1 = typecheck.NodAddr(n1)
+ return mkcall1(chanfn("chansend1", 2, n.Chan.Type()), nil, init, n.Chan, n1)
+}
+
+// walkSlice walks an OSLICE, OSLICEARR, OSLICESTR, OSLICE3, or OSLICE3ARR node.
+func walkSlice(n *ir.SliceExpr, init *ir.Nodes) ir.Node {
+ n.X = walkExpr(n.X, init)
+ n.Low = walkExpr(n.Low, init)
+ if n.Low != nil && ir.IsZero(n.Low) {
+ // Reduce x[0:j] to x[:j] and x[0:j:k] to x[:j:k].
+ n.Low = nil
+ }
+ n.High = walkExpr(n.High, init)
+ n.Max = walkExpr(n.Max, init)
+
+ if (n.Op() == ir.OSLICE || n.Op() == ir.OSLICESTR) && n.Low == nil && n.High == nil {
+ // Reduce x[:] to x.
+ if base.Debug.Slice > 0 {
+ base.Warn("slice: omit slice operation")
+ }
+ return n.X
+ }
+ return n
+}
+
+// walkSliceHeader walks an OSLICEHEADER node.
+func walkSliceHeader(n *ir.SliceHeaderExpr, init *ir.Nodes) ir.Node {
+ n.Ptr = walkExpr(n.Ptr, init)
+ n.Len = walkExpr(n.Len, init)
+ n.Cap = walkExpr(n.Cap, init)
+ return n
+}
+
+// walkStringHeader walks an OSTRINGHEADER node.
+func walkStringHeader(n *ir.StringHeaderExpr, init *ir.Nodes) ir.Node {
+ n.Ptr = walkExpr(n.Ptr, init)
+ n.Len = walkExpr(n.Len, init)
+ return n
+}
+
+// return 1 if integer n must be in range [0, max), 0 otherwise.
+func bounded(n ir.Node, max int64) bool {
+ if n.Type() == nil || !n.Type().IsInteger() {
+ return false
+ }
+
+ sign := n.Type().IsSigned()
+ bits := int32(8 * n.Type().Size())
+
+ if ir.IsSmallIntConst(n) {
+ v := ir.Int64Val(n)
+ return 0 <= v && v < max
+ }
+
+ switch n.Op() {
+ case ir.OAND, ir.OANDNOT:
+ n := n.(*ir.BinaryExpr)
+ v := int64(-1)
+ switch {
+ case ir.IsSmallIntConst(n.X):
+ v = ir.Int64Val(n.X)
+ case ir.IsSmallIntConst(n.Y):
+ v = ir.Int64Val(n.Y)
+ if n.Op() == ir.OANDNOT {
+ v = ^v
+ if !sign {
+ v &= 1<<uint(bits) - 1
+ }
+ }
+ }
+ if 0 <= v && v < max {
+ return true
+ }
+
+ case ir.OMOD:
+ n := n.(*ir.BinaryExpr)
+ if !sign && ir.IsSmallIntConst(n.Y) {
+ v := ir.Int64Val(n.Y)
+ if 0 <= v && v <= max {
+ return true
+ }
+ }
+
+ case ir.ODIV:
+ n := n.(*ir.BinaryExpr)
+ if !sign && ir.IsSmallIntConst(n.Y) {
+ v := ir.Int64Val(n.Y)
+ for bits > 0 && v >= 2 {
+ bits--
+ v >>= 1
+ }
+ }
+
+ case ir.ORSH:
+ n := n.(*ir.BinaryExpr)
+ if !sign && ir.IsSmallIntConst(n.Y) {
+ v := ir.Int64Val(n.Y)
+ if v > int64(bits) {
+ return true
+ }
+ bits -= int32(v)
+ }
+ }
+
+ if !sign && bits <= 62 && 1<<uint(bits) <= max {
+ return true
+ }
+
+ return false
+}
+
+// usemethod checks calls for uses of reflect.Type.{Method,MethodByName}.
+func usemethod(n *ir.CallExpr) {
+ // Don't mark reflect.(*rtype).Method, etc. themselves in the reflect package.
+ // Those functions may be alive via the itab, which should not cause all methods
+ // alive. We only want to mark their callers.
+ if base.Ctxt.Pkgpath == "reflect" {
+ switch ir.CurFunc.Nname.Sym().Name { // TODO: is there a better way than hardcoding the names?
+ case "(*rtype).Method", "(*rtype).MethodByName", "(*interfaceType).Method", "(*interfaceType).MethodByName":
+ return
+ }
+ }
+
+ dot, ok := n.X.(*ir.SelectorExpr)
+ if !ok {
+ return
+ }
+
+ // Looking for either direct method calls and interface method calls of:
+ // reflect.Type.Method - func(int) reflect.Method
+ // reflect.Type.MethodByName - func(string) (reflect.Method, bool)
+ var pKind types.Kind
+
+ switch dot.Sel.Name {
+ case "Method":
+ pKind = types.TINT
+ case "MethodByName":
+ pKind = types.TSTRING
+ default:
+ return
+ }
+
+ t := dot.Selection.Type
+ if t.NumParams() != 1 || t.Params().Field(0).Type.Kind() != pKind {
+ return
+ }
+ switch t.NumResults() {
+ case 1:
+ // ok
+ case 2:
+ if t.Results().Field(1).Type.Kind() != types.TBOOL {
+ return
+ }
+ default:
+ return
+ }
+
+ // Check that first result type is "reflect.Method". Note that we have to check sym name and sym package
+ // separately, as we can't check for exact string "reflect.Method" reliably (e.g., see #19028 and #38515).
+ if s := t.Results().Field(0).Type.Sym(); s != nil && s.Name == "Method" && types.IsReflectPkg(s.Pkg) {
+ ir.CurFunc.SetReflectMethod(true)
+ // The LSym is initialized at this point. We need to set the attribute on the LSym.
+ ir.CurFunc.LSym.Set(obj.AttrReflectMethod, true)
+ }
+}
+
+func usefield(n *ir.SelectorExpr) {
+ if !buildcfg.Experiment.FieldTrack {
+ return
+ }
+
+ switch n.Op() {
+ default:
+ base.Fatalf("usefield %v", n.Op())
+
+ case ir.ODOT, ir.ODOTPTR:
+ break
+ }
+
+ field := n.Selection
+ if field == nil {
+ base.Fatalf("usefield %v %v without paramfld", n.X.Type(), n.Sel)
+ }
+ if field.Sym != n.Sel {
+ base.Fatalf("field inconsistency: %v != %v", field.Sym, n.Sel)
+ }
+ if !strings.Contains(field.Note, "go:\"track\"") {
+ return
+ }
+
+ outer := n.X.Type()
+ if outer.IsPtr() {
+ outer = outer.Elem()
+ }
+ if outer.Sym() == nil {
+ base.Errorf("tracked field must be in named struct type")
+ }
+
+ sym := reflectdata.TrackSym(outer, field)
+ if ir.CurFunc.FieldTrack == nil {
+ ir.CurFunc.FieldTrack = make(map[*obj.LSym]struct{})
+ }
+ ir.CurFunc.FieldTrack[sym] = struct{}{}
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-01 18:11:17 +0000