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path: root/tools/checklocks/checklocks.go
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Diffstat (limited to 'tools/checklocks/checklocks.go')
-rw-r--r--tools/checklocks/checklocks.go758
1 files changed, 0 insertions, 758 deletions
diff --git a/tools/checklocks/checklocks.go b/tools/checklocks/checklocks.go
deleted file mode 100644
index 1e877d394..000000000
--- a/tools/checklocks/checklocks.go
+++ /dev/null
@@ -1,758 +0,0 @@
-// Copyright 2020 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package checklocks performs lock analysis to identify and flag unprotected
-// access to field annotated with a '// +checklocks:<mutex-name>' annotation.
-//
-// For detailed ussage refer to README.md in the same directory.
-package checklocks
-
-import (
- "bytes"
- "fmt"
- "go/ast"
- "go/token"
- "go/types"
- "reflect"
- "regexp"
- "strconv"
- "strings"
-
- "golang.org/x/tools/go/analysis"
- "golang.org/x/tools/go/analysis/passes/buildssa"
- "golang.org/x/tools/go/ssa"
- "gvisor.dev/gvisor/pkg/log"
-)
-
-const (
- checkLocksAnnotation = "// +checklocks:"
- checkLocksIgnore = "// +checklocksignore"
- checkLocksFail = "// +checklocksfail"
-)
-
-// Analyzer is the main entrypoint.
-var Analyzer = &analysis.Analyzer{
- Name: "checklocks",
- Doc: "checks lock preconditions on functions and fields",
- Run: run,
- Requires: []*analysis.Analyzer{buildssa.Analyzer},
- FactTypes: []analysis.Fact{(*lockFieldFacts)(nil), (*lockFunctionFacts)(nil)},
-}
-
-// lockFieldFacts apply on every struct field protected by a lock or that is a
-// lock.
-type lockFieldFacts struct {
- // GuardedBy tracks the names and field numbers that guard this field.
- GuardedBy map[string]int
-
- // IsMutex is true if the field is of type sync.Mutex.
- IsMutex bool
-
- // IsRWMutex is true if the field is of type sync.RWMutex.
- IsRWMutex bool
-
- // FieldNumber is the number of this field in the struct.
- FieldNumber int
-}
-
-// AFact implements analysis.Fact.AFact.
-func (*lockFieldFacts) AFact() {}
-
-type functionGuard struct {
- // ParameterNumber is the index of the object that contains the guarding mutex.
- // This is required during SSA analysis as field names and parameters names are
- // not available in SSA. For example, from the example below ParameterNumber would
- // be 1 and FieldNumber would correspond to the field number of 'mu' within b's type.
- //
- // //+checklocks:b.mu
- // func (a *A) method(b *B, c *C) {
- // ...
- // }
- ParameterNumber int
-
- // FieldNumber is the field index of the mutex in the parameter's struct
- // type. Refer to example above for more details.
- FieldNumber int
-}
-
-// lockFunctionFacts apply on every method.
-type lockFunctionFacts struct {
- // GuardedBy tracks the names and number of parameter (including receiver)
- // lockFuncfields that guard calls to this function.
- // The key is the name specified in the checklocks annotation. e.g given
- // the following code.
- // ```
- // type A struct {
- // mu sync.Mutex
- // a int
- // }
- //
- // // +checklocks:a.mu
- // func xyz(a *A) {..}
- // ```
- //
- // '`+checklocks:a.mu' will result in an entry in this map as shown below.
- // GuardedBy: {"a.mu" => {ParameterNumber: 0, FieldNumber: 0}
- GuardedBy map[string]functionGuard
-}
-
-// AFact implements analysis.Fact.AFact.
-func (*lockFunctionFacts) AFact() {}
-
-type positionKey string
-
-// toPositionKey converts from a token.Position to a key we can use to track
-// failures as the position of the failure annotation is not the same as the
-// position of the actual failure (different column/offsets). Hence we ignore
-// these fields and only use the file/line numbers to track failures.
-func toPositionKey(position token.Position) positionKey {
- return positionKey(fmt.Sprintf("%s:%d", position.Filename, position.Line))
-}
-
-type failData struct {
- pos token.Pos
- count int
-}
-
-func (f failData) String() string {
- return fmt.Sprintf("pos: %d, count: %d", f.pos, f.count)
-}
-
-type passContext struct {
- pass *analysis.Pass
-
- // exemptions tracks functions that should be exempted from lock checking due
- // to '// +checklocksignore' annotation.
- exemptions map[types.Object]struct{}
-
- failures map[positionKey]*failData
-}
-
-var (
- mutexRE = regexp.MustCompile("((.*/)|^)sync.(CrossGoroutineMutex|Mutex)")
- rwMutexRE = regexp.MustCompile("((.*/)|^)sync.(CrossGoroutineRWMutex|RWMutex)")
-)
-
-func (pc *passContext) extractFieldAnnotations(field *ast.Field, fieldType *types.Var) *lockFieldFacts {
- s := fieldType.Type().String()
- // We use HasSuffix below because fieldType can be fully qualified with the
- // package name eg for the gvisor sync package mutex fields have the type:
- // "<package path>/sync/sync.Mutex"
- switch {
- case mutexRE.Match([]byte(s)):
- return &lockFieldFacts{IsMutex: true}
- case rwMutexRE.Match([]byte(s)):
- return &lockFieldFacts{IsRWMutex: true}
- default:
- }
- if field.Doc == nil {
- return nil
- }
- fieldFacts := &lockFieldFacts{GuardedBy: make(map[string]int)}
- for _, l := range field.Doc.List {
- if strings.HasPrefix(l.Text, checkLocksAnnotation) {
- guardName := strings.TrimPrefix(l.Text, checkLocksAnnotation)
- if _, ok := fieldFacts.GuardedBy[guardName]; ok {
- pc.pass.Reportf(field.Pos(), "annotation %s specified more than once.", l.Text)
- continue
- }
- fieldFacts.GuardedBy[guardName] = -1
- }
- }
-
- return fieldFacts
-}
-
-func (pc *passContext) findField(v ssa.Value, fieldNumber int) types.Object {
- structType, ok := v.Type().Underlying().(*types.Struct)
- if !ok {
- structType = v.Type().Underlying().(*types.Pointer).Elem().Underlying().(*types.Struct)
- }
- return structType.Field(fieldNumber)
-}
-
-// findAndExportStructFacts finds any struct fields that are annotated with the
-// "// +checklocks:" annotation and exports relevant facts about the fields to
-// be used in later analysis.
-func (pc *passContext) findAndExportStructFacts(ss *ast.StructType, structType *types.Struct) {
- type fieldRef struct {
- fieldObj *types.Var
- facts *lockFieldFacts
- }
- mutexes := make(map[string]*fieldRef)
- rwMutexes := make(map[string]*fieldRef)
- guardedFields := make(map[string]*fieldRef)
- for i, field := range ss.Fields.List {
- fieldObj := structType.Field(i)
- fieldFacts := pc.extractFieldAnnotations(field, fieldObj)
- if fieldFacts == nil {
- continue
- }
- fieldFacts.FieldNumber = i
-
- ref := &fieldRef{fieldObj, fieldFacts}
- if fieldFacts.IsMutex {
- mutexes[fieldObj.Name()] = ref
- }
- if fieldFacts.IsRWMutex {
- rwMutexes[fieldObj.Name()] = ref
- }
- if len(fieldFacts.GuardedBy) != 0 {
- guardedFields[fieldObj.Name()] = ref
- }
- }
-
- // Export facts about all mutexes.
- for _, f := range mutexes {
- pc.pass.ExportObjectFact(f.fieldObj, f.facts)
- }
- // Export facts about all rwMutexes.
- for _, f := range rwMutexes {
- pc.pass.ExportObjectFact(f.fieldObj, f.facts)
- }
-
- // Validate that guarded fields annotations refer to actual mutexes or
- // rwMutexes in the struct.
- for _, gf := range guardedFields {
- for g := range gf.facts.GuardedBy {
- if f, ok := mutexes[g]; ok {
- gf.facts.GuardedBy[g] = f.facts.FieldNumber
- } else if f, ok := rwMutexes[g]; ok {
- gf.facts.GuardedBy[g] = f.facts.FieldNumber
- } else {
- pc.maybeFail(gf.fieldObj.Pos(), false /* isExempted */, "invalid mutex guard, no such mutex %s in struct %s", g, structType.String())
- continue
- }
- // Export guarded field fact.
- pc.pass.ExportObjectFact(gf.fieldObj, gf.facts)
- }
- }
-}
-
-func (pc *passContext) findAndExportFuncFacts(d *ast.FuncDecl) {
- log.Debugf("finding and exporting function facts\n")
- // for each function definition, check for +checklocks:mu annotation, which
- // means that the function must be called with that lock held.
- fnObj := pc.pass.TypesInfo.ObjectOf(d.Name)
- funcFacts := lockFunctionFacts{GuardedBy: make(map[string]functionGuard)}
- var (
- ignore bool
- ignorePos token.Pos
- )
-
-outerLoop:
- for _, l := range d.Doc.List {
- if strings.HasPrefix(l.Text, checkLocksIgnore) {
- pc.exemptions[fnObj] = struct{}{}
- ignore = true
- ignorePos = l.Pos()
- continue
- }
- if strings.HasPrefix(l.Text, checkLocksAnnotation) {
- guardName := strings.TrimPrefix(l.Text, checkLocksAnnotation)
- if _, ok := funcFacts.GuardedBy[guardName]; ok {
- pc.pass.Reportf(l.Pos(), "annotation %s specified more than once.", l.Text)
- continue
- }
-
- found := false
- x := strings.Split(guardName, ".")
- if len(x) != 2 {
- pc.pass.Reportf(l.Pos(), "checklocks mutex annotation should be of the form 'a.b'")
- continue
- }
- paramName, fieldName := x[0], x[1]
- log.Debugf("paramName: %s, fieldName: %s", paramName, fieldName)
- var paramList []*ast.Field
- if d.Recv != nil {
- paramList = append(paramList, d.Recv.List...)
- }
- if d.Type.Params != nil {
- paramList = append(paramList, d.Type.Params.List...)
- }
- for paramNum, field := range paramList {
- log.Debugf("field names: %+v", field.Names)
- if len(field.Names) == 0 {
- log.Debugf("skipping because parameter is unnamed", paramName)
- continue
- }
- nameExists := false
- for _, name := range field.Names {
- if name.Name == paramName {
- nameExists = true
- }
- }
- if !nameExists {
- log.Debugf("skipping because parameter name(s) does not match : %s", paramName)
- continue
- }
- ptrType, ok := pc.pass.TypesInfo.TypeOf(field.Type).Underlying().(*types.Pointer)
- if !ok {
- // Since mutexes cannot be copied we only care about parameters that
- // are pointer types when checking for guards.
- pc.pass.Reportf(l.Pos(), "annotation %s incorrectly specified, parameter name does not refer to a pointer type", l.Text)
- continue outerLoop
- }
-
- structType, ok := ptrType.Elem().Underlying().(*types.Struct)
- if !ok {
- pc.pass.Reportf(l.Pos(), "annotation %s incorrectly specified, parameter name does not refer to a pointer to a struct", l.Text)
- continue outerLoop
- }
-
- for i := 0; i < structType.NumFields(); i++ {
- if structType.Field(i).Name() == fieldName {
- var fieldFacts lockFieldFacts
- pc.pass.ImportObjectFact(structType.Field(i), &fieldFacts)
- if !fieldFacts.IsMutex && !fieldFacts.IsRWMutex {
- pc.pass.Reportf(l.Pos(), "field %s of param %s is not a mutex or an rwmutex", paramName, structType.Field(i))
- continue outerLoop
- }
- funcFacts.GuardedBy[guardName] = functionGuard{ParameterNumber: paramNum, FieldNumber: i}
- found = true
- continue outerLoop
- }
- }
- if !found {
- pc.pass.Reportf(l.Pos(), "annotation refers to a non-existent field %s in %s", guardName, structType)
- continue outerLoop
- }
- }
- if !found {
- pc.pass.Reportf(l.Pos(), "annotation refers to a non-existent parameter %s", paramName)
- }
- }
- }
-
- if len(funcFacts.GuardedBy) == 0 {
- return
- }
- if ignore {
- pc.pass.Reportf(ignorePos, "//+checklocksignore cannot be specified with other annotations on the function")
- }
- funcObj, ok := pc.pass.TypesInfo.Defs[d.Name].(*types.Func)
- if !ok {
- panic(fmt.Sprintf("function type information missing for %+v", d))
- }
- log.Debugf("export fact for d: %+v, funcObj: %+v, funcFacts: %+v\n", d, funcObj, funcFacts)
- pc.pass.ExportObjectFact(funcObj, &funcFacts)
-}
-
-type mutexState struct {
- // lockedMutexes is used to track which mutexes in a given struct are
- // currently locked using the field number of the mutex as the key.
- lockedMutexes map[int]struct{}
-}
-
-// locksHeld tracks all currently held locks.
-type locksHeld struct {
- locks map[ssa.Value]mutexState
-}
-
-// Same returns true if the locks held by other and l are the same.
-func (l *locksHeld) Same(other *locksHeld) bool {
- return reflect.DeepEqual(l.locks, other.locks)
-}
-
-// Copy creates a copy of all the lock state held by l.
-func (l *locksHeld) Copy() *locksHeld {
- out := &locksHeld{locks: make(map[ssa.Value]mutexState)}
- for ssaVal, mState := range l.locks {
- newLM := make(map[int]struct{})
- for k, v := range mState.lockedMutexes {
- newLM[k] = v
- }
- out.locks[ssaVal] = mutexState{lockedMutexes: newLM}
- }
- return out
-}
-
-func isAlias(first, second ssa.Value) bool {
- if first == second {
- return true
- }
- switch x := first.(type) {
- case *ssa.Field:
- if y, ok := second.(*ssa.Field); ok {
- return x.Field == y.Field && isAlias(x.X, y.X)
- }
- case *ssa.FieldAddr:
- if y, ok := second.(*ssa.FieldAddr); ok {
- return x.Field == y.Field && isAlias(x.X, y.X)
- }
- case *ssa.Index:
- if y, ok := second.(*ssa.Index); ok {
- return isAlias(x.Index, y.Index) && isAlias(x.X, y.X)
- }
- case *ssa.IndexAddr:
- if y, ok := second.(*ssa.IndexAddr); ok {
- return isAlias(x.Index, y.Index) && isAlias(x.X, y.X)
- }
- case *ssa.UnOp:
- if y, ok := second.(*ssa.UnOp); ok {
- return isAlias(x.X, y.X)
- }
- }
- return false
-}
-
-// checkBasicBlocks traverses the control flow graph starting at a set of given
-// block and checks each instruction for allowed operations.
-//
-// funcFact are the exported facts for the enclosing function for these basic
-// blocks.
-func (pc *passContext) checkBasicBlocks(blocks []*ssa.BasicBlock, recoverBlock *ssa.BasicBlock, fn *ssa.Function, funcFact lockFunctionFacts) {
- if len(blocks) == 0 {
- return
- }
-
- // mutexes is used to track currently locked sync.Mutexes/sync.RWMutexes for a
- // given *struct identified by ssa.Value.
- seen := make(map[*ssa.BasicBlock]*locksHeld)
- var scan func(block *ssa.BasicBlock, parent *locksHeld)
- scan = func(block *ssa.BasicBlock, parent *locksHeld) {
- _, isExempted := pc.exemptions[block.Parent().Object()]
- if oldLocksHeld, ok := seen[block]; ok {
- if oldLocksHeld.Same(parent) {
- return
- }
- pc.maybeFail(block.Instrs[0].Pos(), isExempted, "failure entering a block %+v with different sets of lock held, oldLocks: %+v, parentLocks: %+v", block, oldLocksHeld, parent)
- return
- }
- seen[block] = parent
- var lh = parent.Copy()
- for _, inst := range block.Instrs {
- pc.checkInstruction(inst, isExempted, lh)
- }
- for _, b := range block.Succs {
- scan(b, lh)
- }
- }
-
- // Initialize lh with any preconditions that require locks to be held for the
- // method to be invoked.
- lh := &locksHeld{locks: make(map[ssa.Value]mutexState)}
- for _, fg := range funcFact.GuardedBy {
- // The first is the method object itself so we skip that when looking
- // for receiver/function parameters.
- log.Debugf("fn: %s, fn.Operands() == %+v", fn, fn.Operands(nil))
- r := fn.Params[fg.ParameterNumber]
- guardObj := findField(r, fg.FieldNumber)
- var fieldFacts lockFieldFacts
- pc.pass.ImportObjectFact(guardObj, &fieldFacts)
- if fieldFacts.IsMutex || fieldFacts.IsRWMutex {
- m, ok := lh.locks[r]
- if !ok {
- m = mutexState{lockedMutexes: make(map[int]struct{})}
- lh.locks[r] = m
- }
- m.lockedMutexes[fieldFacts.FieldNumber] = struct{}{}
- } else {
- panic(fmt.Sprintf("function: %+v has an invalid guard that is not a mutex: %+v", fn, guardObj))
- }
- }
-
- // Start scanning from the first basic block.
- scan(blocks[0], lh)
-
- // Validate that all blocks were touched.
- for _, b := range blocks {
- if _, ok := seen[b]; !ok && b != recoverBlock {
- panic(fmt.Sprintf("block %+v was not visited during checkBasicBlocks", b))
- }
- }
-}
-
-func (pc *passContext) checkInstruction(inst ssa.Instruction, isExempted bool, lh *locksHeld) {
- log.Debugf("checking instruction: %s, isExempted: %t", inst, isExempted)
- switch x := inst.(type) {
- case *ssa.Field:
- pc.checkFieldAccess(inst, x.X, x.Field, isExempted, lh)
- case *ssa.FieldAddr:
- pc.checkFieldAccess(inst, x.X, x.Field, isExempted, lh)
- case *ssa.Call:
- pc.checkFunctionCall(x, isExempted, lh)
- }
-}
-
-func findField(v ssa.Value, field int) types.Object {
- structType, ok := v.Type().Underlying().(*types.Struct)
- if !ok {
- ptrType, ok := v.Type().Underlying().(*types.Pointer)
- if !ok {
- return nil
- }
- structType = ptrType.Elem().Underlying().(*types.Struct)
- }
- return structType.Field(field)
-}
-
-func (pc *passContext) maybeFail(pos token.Pos, isExempted bool, fmtStr string, args ...interface{}) {
- posKey := toPositionKey(pc.pass.Fset.Position(pos))
- log.Debugf("maybeFail: pos: %d, positionKey: %s", pos, posKey)
- if fData, ok := pc.failures[posKey]; ok {
- fData.count--
- if fData.count == 0 {
- delete(pc.failures, posKey)
- }
- return
- }
- if !isExempted {
- pc.pass.Reportf(pos, fmt.Sprintf(fmtStr, args...))
- }
-}
-
-func (pc *passContext) checkFieldAccess(inst ssa.Instruction, structObj ssa.Value, field int, isExempted bool, lh *locksHeld) {
- var fieldFacts lockFieldFacts
- fieldObj := findField(structObj, field)
- pc.pass.ImportObjectFact(fieldObj, &fieldFacts)
- log.Debugf("fieldObj: %s, fieldFacts: %+v", fieldObj, fieldFacts)
- for _, guardFieldNumber := range fieldFacts.GuardedBy {
- guardObj := findField(structObj, guardFieldNumber)
- var guardfieldFacts lockFieldFacts
- pc.pass.ImportObjectFact(guardObj, &guardfieldFacts)
- log.Debugf("guardObj: %s, guardFieldFacts: %+v", guardObj, guardfieldFacts)
- if guardfieldFacts.IsMutex || guardfieldFacts.IsRWMutex {
- log.Debugf("guard is a mutex")
- m, ok := lh.locks[structObj]
- if !ok {
- pc.maybeFail(inst.Pos(), isExempted, "invalid field access, %s must be locked when accessing %s", guardObj.Name(), fieldObj.Name())
- continue
- }
- if _, ok := m.lockedMutexes[guardfieldFacts.FieldNumber]; !ok {
- pc.maybeFail(inst.Pos(), isExempted, "invalid field access, %s must be locked when accessing %s", guardObj.Name(), fieldObj.Name())
- }
- } else {
- panic("incorrect guard that is not a mutex or an RWMutex")
- }
- }
-}
-
-func (pc *passContext) checkFunctionCall(call *ssa.Call, isExempted bool, lh *locksHeld) {
- // See: https://godoc.org/golang.org/x/tools/go/ssa#CallCommon
- //
- // 1. "call" mode: when Method is nil (!IsInvoke), a CallCommon represents an ordinary
- // function call of the value in Value, which may be a *Builtin, a *Function or any
- // other value of kind 'func'.
- //
- // Value may be one of:
- // (a) a *Function, indicating a statically dispatched call
- // to a package-level function, an anonymous function, or
- // a method of a named type.
- //
- // (b) a *MakeClosure, indicating an immediately applied
- // function literal with free variables.
- //
- // (c) a *Builtin, indicating a statically dispatched call
- // to a built-in function.
- //
- // (d) any other value, indicating a dynamically dispatched
- // function call.
- fn, ok := call.Common().Value.(*ssa.Function)
- if !ok {
- return
- }
- if fn.Object() == nil {
- return
- }
-
- // Check if the function should be called with any locks held.
- var funcFact lockFunctionFacts
- pc.pass.ImportObjectFact(fn.Object(), &funcFact)
- if len(funcFact.GuardedBy) > 0 {
- for _, fg := range funcFact.GuardedBy {
- // The first is the method object itself so we skip that when looking
- // for receiver/function parameters.
- r := (*call.Value().Operands(nil)[fg.ParameterNumber+1])
- guardObj := findField(r, fg.FieldNumber)
- if guardObj == nil {
- continue
- }
- var fieldFacts lockFieldFacts
- pc.pass.ImportObjectFact(guardObj, &fieldFacts)
- if fieldFacts.IsMutex || fieldFacts.IsRWMutex {
- heldMutexes, ok := lh.locks[r]
- if !ok {
- log.Debugf("fn: %s, funcFact: %+v", fn, funcFact)
- pc.maybeFail(call.Pos(), isExempted, "invalid function call %s must be held", guardObj.Name())
- continue
- }
- if _, ok := heldMutexes.lockedMutexes[fg.FieldNumber]; !ok {
- log.Debugf("fn: %s, funcFact: %+v", fn, funcFact)
- pc.maybeFail(call.Pos(), isExempted, "invalid function call %s must be held", guardObj.Name())
- }
- } else {
- panic(fmt.Sprintf("function: %+v has an invalid guard that is not a mutex: %+v", fn, guardObj))
- }
- }
- }
-
- // Check if it's a method dispatch for something in the sync package.
- // See: https://godoc.org/golang.org/x/tools/go/ssa#Function
- if fn.Package() != nil && fn.Package().Pkg.Name() == "sync" && fn.Signature.Recv() != nil {
- r, ok := call.Common().Args[0].(*ssa.FieldAddr)
- if !ok {
- return
- }
- guardObj := findField(r.X, r.Field)
- var fieldFacts lockFieldFacts
- pc.pass.ImportObjectFact(guardObj, &fieldFacts)
- if fieldFacts.IsMutex || fieldFacts.IsRWMutex {
- switch fn.Name() {
- case "Lock", "RLock":
- obj := r.X
- m := mutexState{lockedMutexes: make(map[int]struct{})}
- for k, v := range lh.locks {
- if isAlias(r.X, k) {
- obj = k
- m = v
- }
- }
- if _, ok := m.lockedMutexes[r.Field]; ok {
- // Double locking a mutex that is already locked.
- pc.maybeFail(call.Pos(), isExempted, "trying to a lock %s when already locked", guardObj.Name())
- return
- }
- m.lockedMutexes[r.Field] = struct{}{}
- lh.locks[obj] = m
- case "Unlock", "RUnlock":
- // Find the associated locker object.
- var (
- obj ssa.Value
- m mutexState
- )
- for k, v := range lh.locks {
- if isAlias(r.X, k) {
- obj = k
- m = v
- break
- }
- }
- if _, ok := m.lockedMutexes[r.Field]; !ok {
- pc.maybeFail(call.Pos(), isExempted, "trying to unlock a mutex %s that is already unlocked", guardObj.Name())
- return
- }
- delete(m.lockedMutexes, r.Field)
- if len(m.lockedMutexes) == 0 {
- delete(lh.locks, obj)
- }
- case "RLocker", "DowngradeLock", "TryLock", "TryRLock":
- // we explicitly ignore this for now.
- default:
- panic(fmt.Sprintf("unexpected mutex/rwmutex method invoked: %s", fn.Name()))
- }
- }
- }
-}
-
-func run(pass *analysis.Pass) (interface{}, error) {
- pc := &passContext{
- pass: pass,
- exemptions: make(map[types.Object]struct{}),
- failures: make(map[positionKey]*failData),
- }
-
- // Find all line failure annotations.
- for _, f := range pass.Files {
- for _, cg := range f.Comments {
- for _, c := range cg.List {
- if strings.Contains(c.Text, checkLocksFail) {
- cnt := 1
- if strings.Contains(c.Text, checkLocksFail+":") {
- parts := strings.SplitAfter(c.Text, checkLocksFail+":")
- parsedCount, err := strconv.Atoi(parts[1])
- if err != nil {
- pc.pass.Reportf(c.Pos(), "invalid checklocks annotation : %s", err)
- continue
- }
- cnt = parsedCount
- }
- position := toPositionKey(pass.Fset.Position(c.Pos()))
- pc.failures[position] = &failData{pos: c.Pos(), count: cnt}
- }
- }
- }
- }
-
- // Find all struct declarations and export any relevant facts.
- for _, f := range pass.Files {
- for _, decl := range f.Decls {
- d, ok := decl.(*ast.GenDecl)
- // A GenDecl node (generic declaration node) represents an import,
- // constant, type or variable declaration. We only care about struct
- // declarations so skip any declaration that doesn't declare a new type.
- if !ok || d.Tok != token.TYPE {
- continue
- }
-
- for _, gs := range d.Specs {
- ts := gs.(*ast.TypeSpec)
- ss, ok := ts.Type.(*ast.StructType)
- if !ok {
- continue
- }
- structType := pass.TypesInfo.TypeOf(ts.Name).Underlying().(*types.Struct)
- pc.findAndExportStructFacts(ss, structType)
- }
- }
- }
-
- // Find all method calls and export any relevant facts.
- for _, f := range pass.Files {
- for _, decl := range f.Decls {
- d, ok := decl.(*ast.FuncDecl)
- // Ignore any non function declarations and any functions that do not have
- // any comments.
- if !ok || d.Doc == nil {
- continue
- }
- pc.findAndExportFuncFacts(d)
- }
- }
-
- // log all known facts and all failures if debug logging is enabled.
- allFacts := pass.AllObjectFacts()
- for i := range allFacts {
- log.Debugf("fact.object: %+v, fact.Fact: %+v", allFacts[i].Object, allFacts[i].Fact)
- }
- log.Debugf("all expected failures: %+v", pc.failures)
-
- // Scan all code looking for invalid accesses.
- state := pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA)
- for _, fn := range state.SrcFuncs {
- var funcFact lockFunctionFacts
- // Anonymous(closures) functions do not have an object() but do show up in
- // the SSA.
- if obj := fn.Object(); obj != nil {
- pc.pass.ImportObjectFact(fn.Object(), &funcFact)
- }
-
- log.Debugf("checking function: %s", fn)
- var b bytes.Buffer
- ssa.WriteFunction(&b, fn)
- log.Debugf("function SSA: %s", b.String())
- if fn.Recover != nil {
- pc.checkBasicBlocks([]*ssa.BasicBlock{fn.Recover}, nil, fn, funcFact)
- }
- pc.checkBasicBlocks(fn.Blocks, fn.Recover, fn, funcFact)
- }
-
- // Scan for remaining failures we expect.
- for _, failure := range pc.failures {
- // We are missing expect failures, report as much as possible.
- pass.Reportf(failure.pos, "expected %d failures", failure.count)
- }
-
- return nil, nil
-}