// Copyright 2013 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 pointer // This package defines the treatment of intrinsics, i.e. library // functions requiring special analytical treatment. // // Most of these are C or assembly functions, but even some Go // functions require may special treatment if the analysis completely // replaces the implementation of an API such as reflection. // TODO(adonovan): support a means of writing analytic summaries in // the target code, so that users can summarise the effects of their // own C functions using a snippet of Go. import ( "code.google.com/p/go.tools/ssa" ) // Instances of 'intrinsic' generate analysis constraints for calls to // intrinsic functions. type intrinsic func(a *analysis, cgn *cgnode) // Initialized in explicit init() to defeat (spurious) initialization // cycle error. var intrinsicsByName map[string]intrinsic func init() { // Key strings are from Function.String(). // That little dot ۰ is an Arabic zero numeral (U+06F0), // categories [Nd]. intrinsicsByName = map[string]intrinsic{ // reflect.Value methods. // "(reflect.Value).Addr": ext۰reflect۰Value۰Addr, "(reflect.Value).Bool": ext۰NoEffect, // "(reflect.Value).Bytes": ext۰reflect۰Value۰Bytes, // "(reflect.Value).Call": ext۰reflect۰Value۰Call, // "(reflect.Value).CallSlice": ext۰reflect۰Value۰CallSlice, "(reflect.Value).CanAddr": ext۰NoEffect, "(reflect.Value).CanInterface": ext۰NoEffect, "(reflect.Value).CanSet": ext۰NoEffect, "(reflect.Value).Cap": ext۰NoEffect, "(reflect.Value).Close": ext۰NoEffect, "(reflect.Value).Complex": ext۰NoEffect, // "(reflect.Value).Convert": ext۰reflect۰Value۰Convert, // "(reflect.Value).Elem": ext۰reflect۰Value۰Elem, // "(reflect.Value).Field": ext۰reflect۰Value۰Field, // "(reflect.Value).FieldByIndex": ext۰reflect۰Value۰FieldByIndex, // "(reflect.Value).FieldByName": ext۰reflect۰Value۰FieldByName, // "(reflect.Value).FieldByNameFunc": ext۰reflect۰Value۰FieldByNameFunc, "(reflect.Value).Float": ext۰NoEffect, // "(reflect.Value).Index": ext۰reflect۰Value۰Index, "(reflect.Value).Int": ext۰NoEffect, // "(reflect.Value).Interface": ext۰reflect۰Value۰Interface, "(reflect.Value).InterfaceData": ext۰NoEffect, "(reflect.Value).IsNil": ext۰NoEffect, "(reflect.Value).IsValid": ext۰NoEffect, "(reflect.Value).Kind": ext۰NoEffect, "(reflect.Value).Len": ext۰NoEffect, // "(reflect.Value).MapIndex": ext۰reflect۰Value۰MapIndex, // "(reflect.Value).MapKeys": ext۰reflect۰Value۰MapKeys, // "(reflect.Value).Method": ext۰reflect۰Value۰Method, // "(reflect.Value).MethodByName": ext۰reflect۰Value۰MethodByName, "(reflect.Value).NumField": ext۰NoEffect, "(reflect.Value).NumMethod": ext۰NoEffect, "(reflect.Value).OverflowComplex": ext۰NoEffect, "(reflect.Value).OverflowFloat": ext۰NoEffect, "(reflect.Value).OverflowInt": ext۰NoEffect, "(reflect.Value).OverflowUint": ext۰NoEffect, "(reflect.Value).Pointer": ext۰NoEffect, // "(reflect.Value).Set": ext۰reflect۰Value۰Set, "(reflect.Value).SetBool": ext۰NoEffect, // "(reflect.Value).SetBytes": ext۰reflect۰Value۰SetBytes, "(reflect.Value).SetComplex": ext۰NoEffect, "(reflect.Value).SetFloat": ext۰NoEffect, "(reflect.Value).SetInt": ext۰NoEffect, "(reflect.Value).SetLen": ext۰NoEffect, // "(reflect.Value).SetMapIndex": ext۰reflect۰Value۰SetMapIndex, // "(reflect.Value).SetPointer": ext۰reflect۰Value۰SetPointer, "(reflect.Value).SetString": ext۰NoEffect, "(reflect.Value).SetUint": ext۰NoEffect, // "(reflect.Value).Slice": ext۰reflect۰Value۰Slice, "(reflect.Value).String": ext۰NoEffect, "(reflect.Value).Type": ext۰NoEffect, "(reflect.Value).Uint": ext۰NoEffect, "(reflect.Value).UnsafeAddr": ext۰NoEffect, // Standalone reflect.* functions. "reflect.Append": ext۰NotYetImplemented, "reflect.AppendSlice": ext۰NotYetImplemented, "reflect.Copy": ext۰NotYetImplemented, // "reflect.ChanOf": ext۰reflect۰ChanOf, "reflect.DeepEqual": ext۰NoEffect, // "reflect.Indirect": ext۰reflect۰Indirect, // "reflect.MakeChan": ext۰reflect۰MakeChan, "reflect.MakeFunc": ext۰NotYetImplemented, "reflect.MakeMap": ext۰NotYetImplemented, "reflect.MakeSlice": ext۰NotYetImplemented, "reflect.MapOf": ext۰NotYetImplemented, // "reflect.New": ext۰reflect۰New, // "reflect.NewAt": ext۰reflect۰NewAt, "reflect.PtrTo": ext۰NotYetImplemented, "reflect.Select": ext۰NotYetImplemented, "reflect.SliceOf": ext۰NotYetImplemented, // "reflect.TypeOf": ext۰reflect۰TypeOf, // "reflect.ValueOf": ext۰reflect۰ValueOf, // "reflect.Zero": ext۰reflect۰Zero, "reflect.init": ext۰NoEffect, // *reflect.rtype methods "(*reflect.rtype).Align": ext۰NoEffect, "(*reflect.rtype).AssignableTo": ext۰NoEffect, "(*reflect.rtype).Bits": ext۰NoEffect, "(*reflect.rtype).ChanDir": ext۰NoEffect, "(*reflect.rtype).ConvertibleTo": ext۰NoEffect, // "(*reflect.rtype).Elem": ext۰reflect۰rtype۰Elem, "(*reflect.rtype).Field": ext۰NotYetImplemented, "(*reflect.rtype).FieldAlign": ext۰NoEffect, // "(*reflect.rtype).FieldByIndex": ext۰reflect۰rtype۰FieldByIndex, // "(*reflect.rtype).FieldByName": ext۰reflect۰rtype۰FieldByName, // "(*reflect.rtype).FieldByNameFunc": ext۰reflect۰rtype۰FieldByNameFunc, "(*reflect.rtype).Implements": ext۰NoEffect, // "(*reflect.rtype).In": ext۰reflect۰rtype۰In, "(*reflect.rtype).IsVariadic": ext۰NoEffect, // "(*reflect.rtype).Key": ext۰reflect۰rtype۰Key, "(*reflect.rtype).Kind": ext۰NoEffect, "(*reflect.rtype).Len": ext۰NoEffect, "(*reflect.rtype).Method": ext۰NotYetImplemented, "(*reflect.rtype).MethodByName": ext۰NotYetImplemented, "(*reflect.rtype).Name": ext۰NoEffect, "(*reflect.rtype).NumField": ext۰NoEffect, "(*reflect.rtype).NumIn": ext۰NoEffect, "(*reflect.rtype).NumMethod": ext۰NoEffect, "(*reflect.rtype).NumOut": ext۰NoEffect, // "(*reflect.rtype).Out": ext۰reflect۰rtype۰Out, "(*reflect.rtype).PkgPath": ext۰NoEffect, "(*reflect.rtype).Size": ext۰NoEffect, "(*reflect.rtype).String": ext۰NoEffect, // Other packages. "bytes.Equal": ext۰NoEffect, "bytes.IndexByte": ext۰NoEffect, "math.Abs": ext۰NoEffect, "math.Acos": ext۰NoEffect, "math.Asin": ext۰NoEffect, "math.Atan": ext۰NoEffect, "math.Atan2": ext۰NoEffect, "math.Ceil": ext۰NoEffect, "math.Cos": ext۰NoEffect, "math.Dim": ext۰NoEffect, "math.Exp": ext۰NoEffect, "math.Exp2": ext۰NoEffect, "math.Expm1": ext۰NoEffect, "math.Float32bits": ext۰NoEffect, "math.Float32frombits": ext۰NoEffect, "math.Float64bits": ext۰NoEffect, "math.Float64frombits": ext۰NoEffect, "math.Floor": ext۰NoEffect, "math.Frexp": ext۰NoEffect, "math.Hypot": ext۰NoEffect, "math.Ldexp": ext۰NoEffect, "math.Log": ext۰NoEffect, "math.Log10": ext۰NoEffect, "math.Log1p": ext۰NoEffect, "math.Log2": ext۰NoEffect, "math.Max": ext۰NoEffect, "math.Min": ext۰NoEffect, "math.Mod": ext۰NoEffect, "math.Modf": ext۰NoEffect, "math.Remainder": ext۰NoEffect, "math.Sin": ext۰NoEffect, "math.Sincos": ext۰NoEffect, "math.Sqrt": ext۰NoEffect, "math.Tan": ext۰NoEffect, "math.Trunc": ext۰NoEffect, "math/big.addMulVVW": ext۰NoEffect, "math/big.addVV": ext۰NoEffect, "math/big.addVW": ext۰NoEffect, "math/big.bitLen": ext۰NoEffect, "math/big.divWVW": ext۰NoEffect, "math/big.divWW": ext۰NoEffect, "math/big.mulAddVWW": ext۰NoEffect, "math/big.mulWW": ext۰NoEffect, "math/big.shlVU": ext۰NoEffect, "math/big.shrVU": ext۰NoEffect, "math/big.subVV": ext۰NoEffect, "math/big.subVW": ext۰NoEffect, "os.epipecheck": ext۰NoEffect, "runtime.BlockProfile": ext۰NoEffect, "runtime.Breakpoint": ext۰NoEffect, "runtime.CPUProfile": ext۰NotYetImplemented, "runtime.Caller": ext۰NoEffect, "runtime.FuncForPC": ext۰NotYetImplemented, "runtime.GC": ext۰NoEffect, "runtime.GOMAXPROCS": ext۰NoEffect, "runtime.Goexit": ext۰NoEffect, "runtime.GoroutineProfile": ext۰NoEffect, "runtime.Gosched": ext۰NoEffect, "runtime.MemProfile": ext۰NoEffect, "runtime.NumCPU": ext۰NoEffect, "runtime.NumGoroutine": ext۰NoEffect, "runtime.ReadMemStats": ext۰NoEffect, "runtime.SetBlockProfileRate": ext۰NoEffect, "runtime.SetCPUProfileRate": ext۰NoEffect, "runtime.SetFinalizer": ext۰NotYetImplemented, "runtime.Stack": ext۰NoEffect, "runtime.ThreadCreateProfile": ext۰NoEffect, "runtime.funcentry_go": ext۰NoEffect, "runtime.funcline_go": ext۰NoEffect, "runtime.funcname_go": ext۰NoEffect, "runtime.getgoroot": ext۰NoEffect, "runtime/pprof.runtime_cyclesPerSecond": ext۰NoEffect, "strings.IndexByte": ext۰NoEffect, "sync.runtime_Semacquire": ext۰NoEffect, "sync.runtime_Semrelease": ext۰NoEffect, "sync.runtime_Syncsemcheck": ext۰NoEffect, "sync/atomic.AddInt32": ext۰NoEffect, "sync/atomic.CompareAndSwapInt32": ext۰NoEffect, "sync/atomic.LoadInt32": ext۰NoEffect, "sync/atomic.LoadUint32": ext۰NoEffect, "sync/atomic.StoreInt32": ext۰NoEffect, "sync/atomic.StoreUint32": ext۰NoEffect, "syscall.Close": ext۰NoEffect, "syscall.Exit": ext۰NoEffect, "syscall.Getpid": ext۰NoEffect, "syscall.Getwd": ext۰NoEffect, "syscall.Kill": ext۰NoEffect, "syscall.RawSyscall": ext۰NoEffect, "syscall.Syscall": ext۰NoEffect, "syscall.Syscall6": ext۰NoEffect, "time.Sleep": ext۰NoEffect, "time.now": ext۰NoEffect, "time.startTimer": ext۰NoEffect, "time.stopTimer": ext۰NoEffect, } } // findIntrinsic returns the constraint generation function for an // intrinsic function fn, or nil if the function should be handled normally. // func (a *analysis) findIntrinsic(fn *ssa.Function) intrinsic { // Consult the *Function-keyed cache. // A cached nil indicates a normal non-intrinsic function. impl, ok := a.intrinsics[fn] if !ok { impl = intrinsicsByName[fn.String()] // may be nil // Ensure all "reflect" code is treated intrinsically. if impl == nil && fn.Pkg != nil && a.reflectValueObj != nil && a.reflectValueObj.Pkg() == fn.Pkg.Object { impl = ext۰NotYetImplemented } a.intrinsics[fn] = impl } return impl } // A trivial intrinsic suitable for any function that does not: // 1) induce aliases between its arguments or any global variables; // 2) call any functions; or // 3) create any labels. // // We sometimes violate condition #3 if the function creates only // non-function labels, as the control-flow graph is still sound. // func ext۰NoEffect(a *analysis, cgn *cgnode) {} func ext۰NotYetImplemented(a *analysis, cgn *cgnode) { // TODO(adonovan): enable this warning when we've implemented // enough that it's not unbearably annoying. // a.warnf(fn.Pos(), "unsound: intrinsic treatment of %s not yet implemented", fn) } // We'll model reflect.Value as an interface{} containing pointers. // We must use pointers since some reflect.Values (those derived by // Field, Elem, etc) are abstractions of lvalues, not rvalues, and // mutations via Set are reflected in the underlying value. (We could // represent it as a union of lvalue and rvalue but that's more work.)