+++ /dev/null
-// 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 (
- "fmt"
- "go/types"
-
- "golang.org/x/tools/go/ssa"
-)
-
-// Instances of 'intrinsic' generate analysis constraints for calls to
-// intrinsic functions.
-// Implementations may exploit information from the calling site
-// via cgn.callersite; for shared contours this is nil.
-type intrinsic func(a *analysis, cgn *cgnode)
-
-// Initialized in explicit init() to defeat (spurious) initialization
-// cycle error.
-var intrinsicsByName = make(map[string]intrinsic)
-
-func init() {
- // Key strings are from Function.String().
- // That little dot ۰ is an Arabic zero numeral (U+06F0),
- // categories [Nd].
- for name, fn := range map[string]intrinsic{
- // Other packages.
- "bytes.Equal": ext۰NoEffect,
- "bytes.IndexByte": ext۰NoEffect,
- "crypto/aes.decryptBlockAsm": ext۰NoEffect,
- "crypto/aes.encryptBlockAsm": ext۰NoEffect,
- "crypto/aes.expandKeyAsm": ext۰NoEffect,
- "crypto/aes.hasAsm": ext۰NoEffect,
- "crypto/md5.block": ext۰NoEffect,
- "crypto/rc4.xorKeyStream": ext۰NoEffect,
- "crypto/sha1.block": ext۰NoEffect,
- "crypto/sha256.block": ext۰NoEffect,
- "hash/crc32.castagnoliSSE42": ext۰NoEffect,
- "hash/crc32.haveSSE42": 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,
- "net.runtime_Semacquire": ext۰NoEffect,
- "net.runtime_Semrelease": ext۰NoEffect,
- "net.runtime_pollClose": ext۰NoEffect,
- "net.runtime_pollOpen": ext۰NoEffect,
- "net.runtime_pollReset": ext۰NoEffect,
- "net.runtime_pollServerInit": ext۰NoEffect,
- "net.runtime_pollSetDeadline": ext۰NoEffect,
- "net.runtime_pollUnblock": ext۰NoEffect,
- "net.runtime_pollWait": ext۰NoEffect,
- "net.runtime_pollWaitCanceled": ext۰NoEffect,
- "os.epipecheck": ext۰NoEffect,
- // All other runtime functions are treated as NoEffect.
- "runtime.SetFinalizer": ext۰runtime۰SetFinalizer,
- "strings.IndexByte": ext۰NoEffect,
- "sync.runtime_Semacquire": ext۰NoEffect,
- "sync.runtime_Semrelease": ext۰NoEffect,
- "sync.runtime_Syncsemacquire": ext۰NoEffect,
- "sync.runtime_Syncsemcheck": ext۰NoEffect,
- "sync.runtime_Syncsemrelease": ext۰NoEffect,
- "sync.runtime_procPin": ext۰NoEffect,
- "sync.runtime_procUnpin": ext۰NoEffect,
- "sync.runtime_registerPool": ext۰NoEffect,
- "sync/atomic.AddInt32": ext۰NoEffect,
- "sync/atomic.AddInt64": ext۰NoEffect,
- "sync/atomic.AddUint32": ext۰NoEffect,
- "sync/atomic.AddUint64": ext۰NoEffect,
- "sync/atomic.AddUintptr": ext۰NoEffect,
- "sync/atomic.CompareAndSwapInt32": ext۰NoEffect,
- "sync/atomic.CompareAndSwapUint32": ext۰NoEffect,
- "sync/atomic.CompareAndSwapUint64": ext۰NoEffect,
- "sync/atomic.CompareAndSwapUintptr": ext۰NoEffect,
- "sync/atomic.LoadInt32": ext۰NoEffect,
- "sync/atomic.LoadInt64": ext۰NoEffect,
- "sync/atomic.LoadPointer": ext۰NoEffect, // ignore unsafe.Pointers
- "sync/atomic.LoadUint32": ext۰NoEffect,
- "sync/atomic.LoadUint64": ext۰NoEffect,
- "sync/atomic.LoadUintptr": ext۰NoEffect,
- "sync/atomic.StoreInt32": ext۰NoEffect,
- "sync/atomic.StorePointer": ext۰NoEffect, // ignore unsafe.Pointers
- "sync/atomic.StoreUint32": ext۰NoEffect,
- "sync/atomic.StoreUintptr": ext۰NoEffect,
- "syscall.Close": ext۰NoEffect,
- "syscall.Exit": ext۰NoEffect,
- "syscall.Getpid": ext۰NoEffect,
- "syscall.Getwd": ext۰NoEffect,
- "syscall.Kill": ext۰NoEffect,
- "syscall.RawSyscall": ext۰NoEffect,
- "syscall.RawSyscall6": ext۰NoEffect,
- "syscall.Syscall": ext۰NoEffect,
- "syscall.Syscall6": ext۰NoEffect,
- "syscall.runtime_AfterFork": ext۰NoEffect,
- "syscall.runtime_BeforeFork": ext۰NoEffect,
- "syscall.setenv_c": ext۰NoEffect,
- "time.Sleep": ext۰NoEffect,
- "time.now": ext۰NoEffect,
- "time.startTimer": ext۰time۰startTimer,
- "time.stopTimer": ext۰NoEffect,
- } {
- intrinsicsByName[name] = fn
- }
-}
-
-// 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
-
- if a.isReflect(fn) {
- if !a.config.Reflection {
- impl = ext۰NoEffect // reflection disabled
- } else if impl == nil {
- // Ensure all "reflect" code is treated intrinsically.
- impl = ext۰NotYetImplemented
- }
- } else if impl == nil && fn.Pkg != nil && fn.Pkg.Pkg.Path() == "runtime" {
- // Ignore "runtime" (except SetFinalizer):
- // it has few interesting effects on aliasing
- // and is full of unsafe code we can't analyze.
- impl = ext۰NoEffect
- }
-
- a.intrinsics[fn] = impl
- }
- return impl
-}
-
-// isReflect reports whether fn belongs to the "reflect" package.
-func (a *analysis) isReflect(fn *ssa.Function) bool {
- if a.reflectValueObj == nil {
- return false // "reflect" package not loaded
- }
- reflectPackage := a.reflectValueObj.Pkg()
- if fn.Pkg != nil && fn.Pkg.Pkg == reflectPackage {
- return true
- }
- // Synthetic wrappers have a nil Pkg, so they slip through the
- // previous check. Check the receiver package.
- // TODO(adonovan): should synthetic wrappers have a non-nil Pkg?
- if recv := fn.Signature.Recv(); recv != nil {
- if named, ok := deref(recv.Type()).(*types.Named); ok {
- if named.Obj().Pkg() == reflectPackage {
- return true // e.g. wrapper of (reflect.Value).f
- }
- }
- }
- return false
-}
-
-// 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.
-//
-// Many intrinsics (such as CompareAndSwapInt32) have a fourth kind of
-// effect: loading or storing through a pointer. Though these could
-// be significant, we deliberately ignore them because they are
-// generally not worth the effort.
-//
-// 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) {
- fn := cgn.fn
- a.warnf(fn.Pos(), "unsound: intrinsic treatment of %s not yet implemented", fn)
-}
-
-// ---------- func runtime.SetFinalizer(x, f interface{}) ----------
-
-// runtime.SetFinalizer(x, f)
-type runtimeSetFinalizerConstraint struct {
- targets nodeid // (indirect)
- f nodeid // (ptr)
- x nodeid
-}
-
-func (c *runtimeSetFinalizerConstraint) ptr() nodeid { return c.f }
-func (c *runtimeSetFinalizerConstraint) presolve(h *hvn) {
- h.markIndirect(onodeid(c.targets), "SetFinalizer.targets")
-}
-func (c *runtimeSetFinalizerConstraint) renumber(mapping []nodeid) {
- c.targets = mapping[c.targets]
- c.f = mapping[c.f]
- c.x = mapping[c.x]
-}
-
-func (c *runtimeSetFinalizerConstraint) String() string {
- return fmt.Sprintf("runtime.SetFinalizer(n%d, n%d)", c.x, c.f)
-}
-
-func (c *runtimeSetFinalizerConstraint) solve(a *analysis, delta *nodeset) {
- for _, fObj := range delta.AppendTo(a.deltaSpace) {
- tDyn, f, indirect := a.taggedValue(nodeid(fObj))
- if indirect {
- // TODO(adonovan): we'll need to implement this
- // when we start creating indirect tagged objects.
- panic("indirect tagged object")
- }
-
- tSig, ok := tDyn.Underlying().(*types.Signature)
- if !ok {
- continue // not a function
- }
- if tSig.Recv() != nil {
- panic(tSig)
- }
- if tSig.Params().Len() != 1 {
- continue // not a unary function
- }
-
- // Extract x to tmp.
- tx := tSig.Params().At(0).Type()
- tmp := a.addNodes(tx, "SetFinalizer.tmp")
- a.typeAssert(tx, tmp, c.x, false)
-
- // Call f(tmp).
- a.store(f, tmp, 1, a.sizeof(tx))
-
- // Add dynamic call target.
- if a.onlineCopy(c.targets, f) {
- a.addWork(c.targets)
- }
- }
-}
-
-func ext۰runtime۰SetFinalizer(a *analysis, cgn *cgnode) {
- // This is the shared contour, used for dynamic calls.
- targets := a.addOneNode(tInvalid, "SetFinalizer.targets", nil)
- cgn.sites = append(cgn.sites, &callsite{targets: targets})
- params := a.funcParams(cgn.obj)
- a.addConstraint(&runtimeSetFinalizerConstraint{
- targets: targets,
- x: params,
- f: params + 1,
- })
-}
-
-// ---------- func time.startTimer(t *runtimeTimer) ----------
-
-// time.StartTimer(t)
-type timeStartTimerConstraint struct {
- targets nodeid // (indirect)
- t nodeid // (ptr)
-}
-
-func (c *timeStartTimerConstraint) ptr() nodeid { return c.t }
-func (c *timeStartTimerConstraint) presolve(h *hvn) {
- h.markIndirect(onodeid(c.targets), "StartTimer.targets")
-}
-func (c *timeStartTimerConstraint) renumber(mapping []nodeid) {
- c.targets = mapping[c.targets]
- c.t = mapping[c.t]
-}
-
-func (c *timeStartTimerConstraint) String() string {
- return fmt.Sprintf("time.startTimer(n%d)", c.t)
-}
-
-func (c *timeStartTimerConstraint) solve(a *analysis, delta *nodeset) {
- for _, tObj := range delta.AppendTo(a.deltaSpace) {
- t := nodeid(tObj)
-
- // We model startTimer as if it was defined thus:
- // func startTimer(t *runtimeTimer) { t.f(t.arg) }
-
- // We hard-code the field offsets of time.runtimeTimer:
- // type runtimeTimer struct {
- // 0 __identity__
- // 1 i int32
- // 2 when int64
- // 3 period int64
- // 4 f func(int64, interface{})
- // 5 arg interface{}
- // }
- f := t + 4
- arg := t + 5
-
- // store t.arg to t.f.params[0]
- // (offset 1 => skip identity)
- a.store(f, arg, 1, 1)
-
- // Add dynamic call target.
- if a.onlineCopy(c.targets, f) {
- a.addWork(c.targets)
- }
- }
-}
-
-func ext۰time۰startTimer(a *analysis, cgn *cgnode) {
- // This is the shared contour, used for dynamic calls.
- targets := a.addOneNode(tInvalid, "startTimer.targets", nil)
- cgn.sites = append(cgn.sites, &callsite{targets: targets})
- params := a.funcParams(cgn.obj)
- a.addConstraint(&timeStartTimerConstraint{
- targets: targets,
- t: params,
- })
-}
projects / dotfiles / .git / blobdiff