Includes the latest fix on vet to warn unused context.WithValue result.
Fixes #41149
Change-Id: I06c204f40ef12b0f62f59b1bbdf1fe06ccd6565d
Reviewed-on: https://go-review.googlesource.com/c/go/+/252941
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9
golang.org/x/mod v0.3.1-0.20200828183125-ce943fd02449
golang.org/x/sys v0.0.0-20200501145240-bc7a7d42d5c3 // indirect
- golang.org/x/tools v0.0.0-20200616133436-c1934b75d054
+ golang.org/x/tools v0.0.0-20200901153117-6e59e24738da
golang.org/x/xerrors v0.0.0-20200806184451-1a77d5e9f316 // indirect
)
github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
github.com/ianlancetaylor/demangle v0.0.0-20200414190113-039b1ae3a340 h1:S1+yTUaFPXuDZnPDbO+TrDFIjPzQraYH8/CwSlu9Fac=
github.com/ianlancetaylor/demangle v0.0.0-20200414190113-039b1ae3a340/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
-github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
golang.org/x/arch v0.0.0-20200511175325-f7c78586839d h1:YvwchuJby5xEAPdBGmdAVSiVME50C+RJfJJwJJsGEV8=
golang.org/x/arch v0.0.0-20200511175325-f7c78586839d/go.mod h1:flIaEI6LNU6xOCD5PaJvn9wGP0agmIOqjrtsKGRguv4=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 h1:psW17arqaxU48Z5kZ0CQnkZWQJsqcURM6tKiBApRjXI=
golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.3.1-0.20200828183125-ce943fd02449 h1:xUIPaMhvROX9dhPvRCenIJtU78+lbEenGbgqB5hfHCQ=
golang.org/x/mod v0.3.1-0.20200828183125-ce943fd02449/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191204072324-ce4227a45e2e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200501145240-bc7a7d42d5c3 h1:5B6i6EAiSYyejWfvc5Rc9BbI3rzIsrrXfAQBWnYfn+w=
golang.org/x/sys v0.0.0-20200501145240-bc7a7d42d5c3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20200616133436-c1934b75d054 h1:HHeAlu5H9b71C+Fx0K+1dGgVFN1DM1/wz4aoGOA5qS8=
-golang.org/x/tools v0.0.0-20200616133436-c1934b75d054/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/tools v0.0.0-20200901153117-6e59e24738da h1:8nFbt74voFOsM+Hb5XtF+1SNbbf3dzikH5osZO1hyyo=
+golang.org/x/tools v0.0.0-20200901153117-6e59e24738da/go.mod h1:Cj7w3i3Rnn0Xh82ur9kSqwfTHTeVxaDqrfMjpcNT6bE=
golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20200806184451-1a77d5e9f316 h1:Jhw4VC65LaKnpq9FvcK+a8ZzrFm3D+UygvMMrhkOw70=
golang.org/x/xerrors v0.0.0-20200806184451-1a77d5e9f316/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=
}
for _, enc := range [...]string{"json", "xml"} {
- if reflect.StructTag(tag).Get(enc) != "" {
+ switch reflect.StructTag(tag).Get(enc) {
+ // Ignore warning if the field not exported and the tag is marked as
+ // ignored.
+ case "", "-":
+ default:
pass.Reportf(field.Pos(), "struct field %s has %s tag but is not exported", field.Name(), enc)
return
}
func run(pass *analysis.Pass) (interface{}, error) {
switch pass.Pkg.Path() {
- case "encoding/gob", "encoding/json", "encoding/xml":
+ case "encoding/gob", "encoding/json", "encoding/xml", "encoding/asn1":
// These packages know how to use their own APIs.
// Sometimes they are testing what happens to incorrect programs.
return nil, nil
recv := fn.Type().(*types.Signature).Recv()
if fn.Name() == "Unmarshal" && recv == nil {
// "encoding/json".Unmarshal
- // "encoding/xml".Unmarshal
+ // "encoding/xml".Unmarshal
+ // "encoding/asn1".Unmarshal
switch fn.Pkg().Path() {
- case "encoding/json", "encoding/xml":
+ case "encoding/json", "encoding/xml", "encoding/asn1":
argidx = 1 // func([]byte, interface{})
}
} else if fn.Name() == "Decode" && recv != nil {
func init() {
// TODO(adonovan): provide a comment syntax to allow users to
// add their functions to this set using facts.
- funcs.Set("errors.New,fmt.Errorf,fmt.Sprintf,fmt.Sprint,sort.Reverse")
+ funcs.Set("errors.New,fmt.Errorf,fmt.Sprintf,fmt.Sprint,sort.Reverse,context.WithValue,context.WithCancel,context.WithDeadline,context.WithTimeout")
Analyzer.Flags.Var(&funcs, "funcs",
"comma-separated list of functions whose results must be used")
"strings"
"golang.org/x/tools/go/ast/astutil"
+ "golang.org/x/tools/internal/lsp/fuzzy"
+)
+
+var (
+ GetTypeErrors func(p interface{}) []types.Error
+ SetTypeErrors func(p interface{}, errors []types.Error)
)
func TypeErrorEndPos(fset *token.FileSet, src []byte, start token.Pos) token.Pos {
default:
panic("unknown basic type")
}
- case *types.Chan, *types.Interface, *types.Map, *types.Pointer, *types.Signature, *types.Slice:
+ case *types.Chan, *types.Interface, *types.Map, *types.Pointer, *types.Signature, *types.Slice, *types.Array:
return ast.NewIdent("nil")
case *types.Struct:
- texpr := typeExpr(fset, f, pkg, typ) // typ because we want the name here.
+ texpr := TypeExpr(fset, f, pkg, typ) // typ because we want the name here.
if texpr == nil {
return nil
}
return &ast.CompositeLit{
Type: texpr,
}
- case *types.Array:
- texpr := typeExpr(fset, f, pkg, u.Elem())
- if texpr == nil {
- return nil
- }
- return &ast.CompositeLit{
- Type: &ast.ArrayType{
- Elt: texpr,
- Len: &ast.BasicLit{Kind: token.INT, Value: fmt.Sprintf("%v", u.Len())},
- },
- }
}
return nil
}
-func typeExpr(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.Type) ast.Expr {
+// IsZeroValue checks whether the given expression is a 'zero value' (as determined by output of
+// analysisinternal.ZeroValue)
+func IsZeroValue(expr ast.Expr) bool {
+ switch e := expr.(type) {
+ case *ast.BasicLit:
+ return e.Value == "0" || e.Value == `""`
+ case *ast.Ident:
+ return e.Name == "nil" || e.Name == "false"
+ default:
+ return false
+ }
+}
+
+func TypeExpr(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.Type) ast.Expr {
switch t := typ.(type) {
case *types.Basic:
switch t.Kind() {
default:
return ast.NewIdent(t.Name())
}
+ case *types.Pointer:
+ x := TypeExpr(fset, f, pkg, t.Elem())
+ if x == nil {
+ return nil
+ }
+ return &ast.UnaryExpr{
+ Op: token.MUL,
+ X: x,
+ }
+ case *types.Array:
+ elt := TypeExpr(fset, f, pkg, t.Elem())
+ if elt == nil {
+ return nil
+ }
+ return &ast.ArrayType{
+ Len: &ast.BasicLit{
+ Kind: token.INT,
+ Value: fmt.Sprintf("%d", t.Len()),
+ },
+ Elt: elt,
+ }
+ case *types.Slice:
+ elt := TypeExpr(fset, f, pkg, t.Elem())
+ if elt == nil {
+ return nil
+ }
+ return &ast.ArrayType{
+ Elt: elt,
+ }
+ case *types.Map:
+ key := TypeExpr(fset, f, pkg, t.Key())
+ value := TypeExpr(fset, f, pkg, t.Elem())
+ if key == nil || value == nil {
+ return nil
+ }
+ return &ast.MapType{
+ Key: key,
+ Value: value,
+ }
+ case *types.Chan:
+ dir := ast.ChanDir(t.Dir())
+ if t.Dir() == types.SendRecv {
+ dir = ast.SEND | ast.RECV
+ }
+ value := TypeExpr(fset, f, pkg, t.Elem())
+ if value == nil {
+ return nil
+ }
+ return &ast.ChanType{
+ Dir: dir,
+ Value: value,
+ }
+ case *types.Signature:
+ var params []*ast.Field
+ for i := 0; i < t.Params().Len(); i++ {
+ p := TypeExpr(fset, f, pkg, t.Params().At(i).Type())
+ if p == nil {
+ return nil
+ }
+ params = append(params, &ast.Field{
+ Type: p,
+ Names: []*ast.Ident{
+ {
+ Name: t.Params().At(i).Name(),
+ },
+ },
+ })
+ }
+ var returns []*ast.Field
+ for i := 0; i < t.Results().Len(); i++ {
+ r := TypeExpr(fset, f, pkg, t.Results().At(i).Type())
+ if r == nil {
+ return nil
+ }
+ returns = append(returns, &ast.Field{
+ Type: r,
+ })
+ }
+ return &ast.FuncType{
+ Params: &ast.FieldList{
+ List: params,
+ },
+ Results: &ast.FieldList{
+ List: returns,
+ },
+ }
case *types.Named:
+ if t.Obj().Pkg() == nil {
+ return ast.NewIdent(t.Obj().Name())
+ }
if t.Obj().Pkg() == pkg {
return ast.NewIdent(t.Obj().Name())
}
X: ast.NewIdent(pkgName),
Sel: ast.NewIdent(t.Obj().Name()),
}
+ case *types.Struct:
+ return ast.NewIdent(t.String())
+ case *types.Interface:
+ return ast.NewIdent(t.String())
default:
- return nil // TODO: anonymous structs, but who does that
+ return nil
}
}
-var GetTypeErrors = func(p interface{}) []types.Error { return nil }
-var SetTypeErrors = func(p interface{}, errors []types.Error) {}
-
type TypeErrorPass string
const (
NoResultValues TypeErrorPass = "noresultvalues"
UndeclaredName TypeErrorPass = "undeclaredname"
)
+
+// StmtToInsertVarBefore returns the ast.Stmt before which we can safely insert a new variable.
+// Some examples:
+//
+// Basic Example:
+// z := 1
+// y := z + x
+// If x is undeclared, then this function would return `y := z + x`, so that we
+// can insert `x := ` on the line before `y := z + x`.
+//
+// If stmt example:
+// if z == 1 {
+// } else if z == y {}
+// If y is undeclared, then this function would return `if z == 1 {`, because we cannot
+// insert a statement between an if and an else if statement. As a result, we need to find
+// the top of the if chain to insert `y := ` before.
+func StmtToInsertVarBefore(path []ast.Node) ast.Stmt {
+ enclosingIndex := -1
+ for i, p := range path {
+ if _, ok := p.(ast.Stmt); ok {
+ enclosingIndex = i
+ break
+ }
+ }
+ if enclosingIndex == -1 {
+ return nil
+ }
+ enclosingStmt := path[enclosingIndex]
+ switch enclosingStmt.(type) {
+ case *ast.IfStmt:
+ // The enclosingStmt is inside of the if declaration,
+ // We need to check if we are in an else-if stmt and
+ // get the base if statement.
+ return baseIfStmt(path, enclosingIndex)
+ case *ast.CaseClause:
+ // Get the enclosing switch stmt if the enclosingStmt is
+ // inside of the case statement.
+ for i := enclosingIndex + 1; i < len(path); i++ {
+ if node, ok := path[i].(*ast.SwitchStmt); ok {
+ return node
+ } else if node, ok := path[i].(*ast.TypeSwitchStmt); ok {
+ return node
+ }
+ }
+ }
+ if len(path) <= enclosingIndex+1 {
+ return enclosingStmt.(ast.Stmt)
+ }
+ // Check if the enclosing statement is inside another node.
+ switch expr := path[enclosingIndex+1].(type) {
+ case *ast.IfStmt:
+ // Get the base if statement.
+ return baseIfStmt(path, enclosingIndex+1)
+ case *ast.ForStmt:
+ if expr.Init == enclosingStmt || expr.Post == enclosingStmt {
+ return expr
+ }
+ }
+ return enclosingStmt.(ast.Stmt)
+}
+
+// baseIfStmt walks up the if/else-if chain until we get to
+// the top of the current if chain.
+func baseIfStmt(path []ast.Node, index int) ast.Stmt {
+ stmt := path[index]
+ for i := index + 1; i < len(path); i++ {
+ if node, ok := path[i].(*ast.IfStmt); ok && node.Else == stmt {
+ stmt = node
+ continue
+ }
+ break
+ }
+ return stmt.(ast.Stmt)
+}
+
+// WalkASTWithParent walks the AST rooted at n. The semantics are
+// similar to ast.Inspect except it does not call f(nil).
+func WalkASTWithParent(n ast.Node, f func(n ast.Node, parent ast.Node) bool) {
+ var ancestors []ast.Node
+ ast.Inspect(n, func(n ast.Node) (recurse bool) {
+ if n == nil {
+ ancestors = ancestors[:len(ancestors)-1]
+ return false
+ }
+
+ var parent ast.Node
+ if len(ancestors) > 0 {
+ parent = ancestors[len(ancestors)-1]
+ }
+ ancestors = append(ancestors, n)
+ return f(n, parent)
+ })
+}
+
+// FindMatchingIdents finds all identifiers in 'node' that match any of the given types.
+// 'pos' represents the position at which the identifiers may be inserted. 'pos' must be within
+// the scope of each of identifier we select. Otherwise, we will insert a variable at 'pos' that
+// is unrecognized.
+func FindMatchingIdents(typs []types.Type, node ast.Node, pos token.Pos, info *types.Info, pkg *types.Package) map[types.Type][]*ast.Ident {
+ matches := map[types.Type][]*ast.Ident{}
+ // Initialize matches to contain the variable types we are searching for.
+ for _, typ := range typs {
+ if typ == nil {
+ continue
+ }
+ matches[typ] = []*ast.Ident{}
+ }
+ seen := map[types.Object]struct{}{}
+ ast.Inspect(node, func(n ast.Node) bool {
+ if n == nil {
+ return false
+ }
+ // Prevent circular definitions. If 'pos' is within an assignment statement, do not
+ // allow any identifiers in that assignment statement to be selected. Otherwise,
+ // we could do the following, where 'x' satisfies the type of 'f0':
+ //
+ // x := fakeStruct{f0: x}
+ //
+ assignment, ok := n.(*ast.AssignStmt)
+ if ok && pos > assignment.Pos() && pos <= assignment.End() {
+ return false
+ }
+ if n.End() > pos {
+ return n.Pos() <= pos
+ }
+ ident, ok := n.(*ast.Ident)
+ if !ok || ident.Name == "_" {
+ return true
+ }
+ obj := info.Defs[ident]
+ if obj == nil || obj.Type() == nil {
+ return true
+ }
+ if _, ok := obj.(*types.TypeName); ok {
+ return true
+ }
+ // Prevent duplicates in matches' values.
+ if _, ok = seen[obj]; ok {
+ return true
+ }
+ seen[obj] = struct{}{}
+ // Find the scope for the given position. Then, check whether the object
+ // exists within the scope.
+ innerScope := pkg.Scope().Innermost(pos)
+ if innerScope == nil {
+ return true
+ }
+ _, foundObj := innerScope.LookupParent(ident.Name, pos)
+ if foundObj != obj {
+ return true
+ }
+ // The object must match one of the types that we are searching for.
+ if idents, ok := matches[obj.Type()]; ok {
+ matches[obj.Type()] = append(idents, ast.NewIdent(ident.Name))
+ }
+ // If the object type does not exactly match any of the target types, greedily
+ // find the first target type that the object type can satisfy.
+ for typ := range matches {
+ if obj.Type() == typ {
+ continue
+ }
+ if equivalentTypes(obj.Type(), typ) {
+ matches[typ] = append(matches[typ], ast.NewIdent(ident.Name))
+ }
+ }
+ return true
+ })
+ return matches
+}
+
+func equivalentTypes(want, got types.Type) bool {
+ if want == got || types.Identical(want, got) {
+ return true
+ }
+ // Code segment to help check for untyped equality from (golang/go#32146).
+ if rhs, ok := want.(*types.Basic); ok && rhs.Info()&types.IsUntyped > 0 {
+ if lhs, ok := got.Underlying().(*types.Basic); ok {
+ return rhs.Info()&types.IsConstType == lhs.Info()&types.IsConstType
+ }
+ }
+ return types.AssignableTo(want, got)
+}
+
+// FindBestMatch employs fuzzy matching to evaluate the similarity of each given identifier to the
+// given pattern. We return the identifier whose name is most similar to the pattern.
+func FindBestMatch(pattern string, idents []*ast.Ident) ast.Expr {
+ fuzz := fuzzy.NewMatcher(pattern)
+ var bestFuzz ast.Expr
+ highScore := float32(0) // minimum score is 0 (no match)
+ for _, ident := range idents {
+ // TODO: Improve scoring algorithm.
+ score := fuzz.Score(ident.Name)
+ if score > highScore {
+ highScore = score
+ bestFuzz = ident
+ } else if score == 0 {
+ // Order matters in the fuzzy matching algorithm. If we find no match
+ // when matching the target to the identifier, try matching the identifier
+ // to the target.
+ revFuzz := fuzzy.NewMatcher(ident.Name)
+ revScore := revFuzz.Score(pattern)
+ if revScore > highScore {
+ highScore = revScore
+ bestFuzz = ident
+ }
+ }
+ }
+ return bestFuzz
+}
--- /dev/null
+// Copyright 2019 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 fuzzy
+
+import (
+ "unicode"
+)
+
+// RuneRole specifies the role of a rune in the context of an input.
+type RuneRole byte
+
+const (
+ // RNone specifies a rune without any role in the input (i.e., whitespace/non-ASCII).
+ RNone RuneRole = iota
+ // RSep specifies a rune with the role of segment separator.
+ RSep
+ // RTail specifies a rune which is a lower-case tail in a word in the input.
+ RTail
+ // RUCTail specifies a rune which is an upper-case tail in a word in the input.
+ RUCTail
+ // RHead specifies a rune which is the first character in a word in the input.
+ RHead
+)
+
+// RuneRoles detects the roles of each byte rune in an input string and stores it in the output
+// slice. The rune role depends on the input type. Stops when it parsed all the runes in the string
+// or when it filled the output. If output is nil, then it gets created.
+func RuneRoles(str string, reuse []RuneRole) []RuneRole {
+ var output []RuneRole
+ if cap(reuse) < len(str) {
+ output = make([]RuneRole, 0, len(str))
+ } else {
+ output = reuse[:0]
+ }
+
+ prev, prev2 := rtNone, rtNone
+ for i := 0; i < len(str); i++ {
+ r := rune(str[i])
+
+ role := RNone
+
+ curr := rtLower
+ if str[i] <= unicode.MaxASCII {
+ curr = runeType(rt[str[i]] - '0')
+ }
+
+ if curr == rtLower {
+ if prev == rtNone || prev == rtPunct {
+ role = RHead
+ } else {
+ role = RTail
+ }
+ } else if curr == rtUpper {
+ role = RHead
+
+ if prev == rtUpper {
+ // This and previous characters are both upper case.
+
+ if i+1 == len(str) {
+ // This is last character, previous was also uppercase -> this is UCTail
+ // i.e., (current char is C): aBC / BC / ABC
+ role = RUCTail
+ }
+ }
+ } else if curr == rtPunct {
+ switch r {
+ case '.', ':':
+ role = RSep
+ }
+ }
+ if curr != rtLower {
+ if i > 1 && output[i-1] == RHead && prev2 == rtUpper && (output[i-2] == RHead || output[i-2] == RUCTail) {
+ // The previous two characters were uppercase. The current one is not a lower case, so the
+ // previous one can't be a HEAD. Make it a UCTail.
+ // i.e., (last char is current char - B must be a UCTail): ABC / ZABC / AB.
+ output[i-1] = RUCTail
+ }
+ }
+
+ output = append(output, role)
+ prev2 = prev
+ prev = curr
+ }
+ return output
+}
+
+type runeType byte
+
+const (
+ rtNone runeType = iota
+ rtPunct
+ rtLower
+ rtUpper
+)
+
+const rt = "00000000000000000000000000000000000000000000001122222222221000000333333333333333333333333330000002222222222222222222222222200000"
+
+// LastSegment returns the substring representing the last segment from the input, where each
+// byte has an associated RuneRole in the roles slice. This makes sense only for inputs of Symbol
+// or Filename type.
+func LastSegment(input string, roles []RuneRole) string {
+ // Exclude ending separators.
+ end := len(input) - 1
+ for end >= 0 && roles[end] == RSep {
+ end--
+ }
+ if end < 0 {
+ return ""
+ }
+
+ start := end - 1
+ for start >= 0 && roles[start] != RSep {
+ start--
+ }
+
+ return input[start+1 : end+1]
+}
+
+// ToLower transforms the input string to lower case, which is stored in the output byte slice.
+// The lower casing considers only ASCII values - non ASCII values are left unmodified.
+// Stops when parsed all input or when it filled the output slice. If output is nil, then it gets
+// created.
+func ToLower(input string, reuse []byte) []byte {
+ output := reuse
+ if cap(reuse) < len(input) {
+ output = make([]byte, len(input))
+ }
+
+ for i := 0; i < len(input); i++ {
+ r := rune(input[i])
+ if r <= unicode.MaxASCII {
+ if 'A' <= r && r <= 'Z' {
+ r += 'a' - 'A'
+ }
+ }
+ output[i] = byte(r)
+ }
+ return output[:len(input)]
+}
+
+// WordConsumer defines a consumer for a word delimited by the [start,end) byte offsets in an input
+// (start is inclusive, end is exclusive).
+type WordConsumer func(start, end int)
+
+// Words find word delimiters in an input based on its bytes' mappings to rune roles. The offset
+// delimiters for each word are fed to the provided consumer function.
+func Words(roles []RuneRole, consume WordConsumer) {
+ var wordStart int
+ for i, r := range roles {
+ switch r {
+ case RUCTail, RTail:
+ case RHead, RNone, RSep:
+ if i != wordStart {
+ consume(wordStart, i)
+ }
+ wordStart = i
+ if r != RHead {
+ // Skip this character.
+ wordStart = i + 1
+ }
+ }
+ }
+ if wordStart != len(roles) {
+ consume(wordStart, len(roles))
+ }
+}
--- /dev/null
+// Copyright 2019 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 fuzzy implements a fuzzy matching algorithm.
+package fuzzy
+
+import (
+ "bytes"
+ "fmt"
+)
+
+const (
+ // MaxInputSize is the maximum size of the input scored against the fuzzy matcher. Longer inputs
+ // will be truncated to this size.
+ MaxInputSize = 127
+ // MaxPatternSize is the maximum size of the pattern used to construct the fuzzy matcher. Longer
+ // inputs are truncated to this size.
+ MaxPatternSize = 63
+)
+
+type scoreVal int
+
+func (s scoreVal) val() int {
+ return int(s) >> 1
+}
+
+func (s scoreVal) prevK() int {
+ return int(s) & 1
+}
+
+func score(val int, prevK int /*0 or 1*/) scoreVal {
+ return scoreVal(val<<1 + prevK)
+}
+
+// Matcher implements a fuzzy matching algorithm for scoring candidates against a pattern.
+// The matcher does not support parallel usage.
+type Matcher struct {
+ pattern string
+ patternLower []byte // lower-case version of the pattern
+ patternShort []byte // first characters of the pattern
+ caseSensitive bool // set if the pattern is mix-cased
+
+ patternRoles []RuneRole // the role of each character in the pattern
+ roles []RuneRole // the role of each character in the tested string
+
+ scores [MaxInputSize + 1][MaxPatternSize + 1][2]scoreVal
+
+ scoreScale float32
+
+ lastCandidateLen int // in bytes
+ lastCandidateMatched bool
+
+ // Here we save the last candidate in lower-case. This is basically a byte slice we reuse for
+ // performance reasons, so the slice is not reallocated for every candidate.
+ lowerBuf [MaxInputSize]byte
+ rolesBuf [MaxInputSize]RuneRole
+}
+
+func (m *Matcher) bestK(i, j int) int {
+ if m.scores[i][j][0].val() < m.scores[i][j][1].val() {
+ return 1
+ }
+ return 0
+}
+
+// NewMatcher returns a new fuzzy matcher for scoring candidates against the provided pattern.
+func NewMatcher(pattern string) *Matcher {
+ if len(pattern) > MaxPatternSize {
+ pattern = pattern[:MaxPatternSize]
+ }
+
+ m := &Matcher{
+ pattern: pattern,
+ patternLower: ToLower(pattern, nil),
+ }
+
+ for i, c := range m.patternLower {
+ if pattern[i] != c {
+ m.caseSensitive = true
+ break
+ }
+ }
+
+ if len(pattern) > 3 {
+ m.patternShort = m.patternLower[:3]
+ } else {
+ m.patternShort = m.patternLower
+ }
+
+ m.patternRoles = RuneRoles(pattern, nil)
+
+ if len(pattern) > 0 {
+ maxCharScore := 4
+ m.scoreScale = 1 / float32(maxCharScore*len(pattern))
+ }
+
+ return m
+}
+
+// Score returns the score returned by matching the candidate to the pattern.
+// This is not designed for parallel use. Multiple candidates must be scored sequentially.
+// Returns a score between 0 and 1 (0 - no match, 1 - perfect match).
+func (m *Matcher) Score(candidate string) float32 {
+ if len(candidate) > MaxInputSize {
+ candidate = candidate[:MaxInputSize]
+ }
+ lower := ToLower(candidate, m.lowerBuf[:])
+ m.lastCandidateLen = len(candidate)
+
+ if len(m.pattern) == 0 {
+ // Empty patterns perfectly match candidates.
+ return 1
+ }
+
+ if m.match(candidate, lower) {
+ sc := m.computeScore(candidate, lower)
+ if sc > minScore/2 && !m.poorMatch() {
+ m.lastCandidateMatched = true
+ if len(m.pattern) == len(candidate) {
+ // Perfect match.
+ return 1
+ }
+
+ if sc < 0 {
+ sc = 0
+ }
+ normalizedScore := float32(sc) * m.scoreScale
+ if normalizedScore > 1 {
+ normalizedScore = 1
+ }
+
+ return normalizedScore
+ }
+ }
+
+ m.lastCandidateMatched = false
+ return 0
+}
+
+const minScore = -10000
+
+// MatchedRanges returns matches ranges for the last scored string as a flattened array of
+// [begin, end) byte offset pairs.
+func (m *Matcher) MatchedRanges() []int {
+ if len(m.pattern) == 0 || !m.lastCandidateMatched {
+ return nil
+ }
+ i, j := m.lastCandidateLen, len(m.pattern)
+ if m.scores[i][j][0].val() < minScore/2 && m.scores[i][j][1].val() < minScore/2 {
+ return nil
+ }
+
+ var ret []int
+ k := m.bestK(i, j)
+ for i > 0 {
+ take := (k == 1)
+ k = m.scores[i][j][k].prevK()
+ if take {
+ if len(ret) == 0 || ret[len(ret)-1] != i {
+ ret = append(ret, i)
+ ret = append(ret, i-1)
+ } else {
+ ret[len(ret)-1] = i - 1
+ }
+ j--
+ }
+ i--
+ }
+ // Reverse slice.
+ for i := 0; i < len(ret)/2; i++ {
+ ret[i], ret[len(ret)-1-i] = ret[len(ret)-1-i], ret[i]
+ }
+ return ret
+}
+
+func (m *Matcher) match(candidate string, candidateLower []byte) bool {
+ i, j := 0, 0
+ for ; i < len(candidateLower) && j < len(m.patternLower); i++ {
+ if candidateLower[i] == m.patternLower[j] {
+ j++
+ }
+ }
+ if j != len(m.patternLower) {
+ return false
+ }
+
+ // The input passes the simple test against pattern, so it is time to classify its characters.
+ // Character roles are used below to find the last segment.
+ m.roles = RuneRoles(candidate, m.rolesBuf[:])
+
+ return true
+}
+
+func (m *Matcher) computeScore(candidate string, candidateLower []byte) int {
+ pattLen, candLen := len(m.pattern), len(candidate)
+
+ for j := 0; j <= len(m.pattern); j++ {
+ m.scores[0][j][0] = minScore << 1
+ m.scores[0][j][1] = minScore << 1
+ }
+ m.scores[0][0][0] = score(0, 0) // Start with 0.
+
+ segmentsLeft, lastSegStart := 1, 0
+ for i := 0; i < candLen; i++ {
+ if m.roles[i] == RSep {
+ segmentsLeft++
+ lastSegStart = i + 1
+ }
+ }
+
+ // A per-character bonus for a consecutive match.
+ consecutiveBonus := 2
+ wordIdx := 0 // Word count within segment.
+ for i := 1; i <= candLen; i++ {
+
+ role := m.roles[i-1]
+ isHead := role == RHead
+
+ if isHead {
+ wordIdx++
+ } else if role == RSep && segmentsLeft > 1 {
+ wordIdx = 0
+ segmentsLeft--
+ }
+
+ var skipPenalty int
+ if i == 1 || (i-1) == lastSegStart {
+ // Skipping the start of first or last segment.
+ skipPenalty++
+ }
+
+ for j := 0; j <= pattLen; j++ {
+ // By default, we don't have a match. Fill in the skip data.
+ m.scores[i][j][1] = minScore << 1
+
+ // Compute the skip score.
+ k := 0
+ if m.scores[i-1][j][0].val() < m.scores[i-1][j][1].val() {
+ k = 1
+ }
+
+ skipScore := m.scores[i-1][j][k].val()
+ // Do not penalize missing characters after the last matched segment.
+ if j != pattLen {
+ skipScore -= skipPenalty
+ }
+ m.scores[i][j][0] = score(skipScore, k)
+
+ if j == 0 || candidateLower[i-1] != m.patternLower[j-1] {
+ // Not a match.
+ continue
+ }
+ pRole := m.patternRoles[j-1]
+
+ if role == RTail && pRole == RHead {
+ if j > 1 {
+ // Not a match: a head in the pattern matches a tail character in the candidate.
+ continue
+ }
+ // Special treatment for the first character of the pattern. We allow
+ // matches in the middle of a word if they are long enough, at least
+ // min(3, pattern.length) characters.
+ if !bytes.HasPrefix(candidateLower[i-1:], m.patternShort) {
+ continue
+ }
+ }
+
+ // Compute the char score.
+ var charScore int
+ // Bonus 1: the char is in the candidate's last segment.
+ if segmentsLeft <= 1 {
+ charScore++
+ }
+ // Bonus 2: Case match or a Head in the pattern aligns with one in the word.
+ // Single-case patterns lack segmentation signals and we assume any character
+ // can be a head of a segment.
+ if candidate[i-1] == m.pattern[j-1] || role == RHead && (!m.caseSensitive || pRole == RHead) {
+ charScore++
+ }
+
+ // Penalty 1: pattern char is Head, candidate char is Tail.
+ if role == RTail && pRole == RHead {
+ charScore--
+ }
+ // Penalty 2: first pattern character matched in the middle of a word.
+ if j == 1 && role == RTail {
+ charScore -= 4
+ }
+
+ // Third dimension encodes whether there is a gap between the previous match and the current
+ // one.
+ for k := 0; k < 2; k++ {
+ sc := m.scores[i-1][j-1][k].val() + charScore
+
+ isConsecutive := k == 1 || i-1 == 0 || i-1 == lastSegStart
+ if isConsecutive {
+ // Bonus 3: a consecutive match. First character match also gets a bonus to
+ // ensure prefix final match score normalizes to 1.0.
+ // Logically, this is a part of charScore, but we have to compute it here because it
+ // only applies for consecutive matches (k == 1).
+ sc += consecutiveBonus
+ }
+ if k == 0 {
+ // Penalty 3: Matching inside a segment (and previous char wasn't matched). Penalize for the lack
+ // of alignment.
+ if role == RTail || role == RUCTail {
+ sc -= 3
+ }
+ }
+
+ if sc > m.scores[i][j][1].val() {
+ m.scores[i][j][1] = score(sc, k)
+ }
+ }
+ }
+ }
+
+ result := m.scores[len(candidate)][len(m.pattern)][m.bestK(len(candidate), len(m.pattern))].val()
+
+ return result
+}
+
+// ScoreTable returns the score table computed for the provided candidate. Used only for debugging.
+func (m *Matcher) ScoreTable(candidate string) string {
+ var buf bytes.Buffer
+
+ var line1, line2, separator bytes.Buffer
+ line1.WriteString("\t")
+ line2.WriteString("\t")
+ for j := 0; j < len(m.pattern); j++ {
+ line1.WriteString(fmt.Sprintf("%c\t\t", m.pattern[j]))
+ separator.WriteString("----------------")
+ }
+
+ buf.WriteString(line1.String())
+ buf.WriteString("\n")
+ buf.WriteString(separator.String())
+ buf.WriteString("\n")
+
+ for i := 1; i <= len(candidate); i++ {
+ line1.Reset()
+ line2.Reset()
+
+ line1.WriteString(fmt.Sprintf("%c\t", candidate[i-1]))
+ line2.WriteString("\t")
+
+ for j := 1; j <= len(m.pattern); j++ {
+ line1.WriteString(fmt.Sprintf("M%6d(%c)\t", m.scores[i][j][0].val(), dir(m.scores[i][j][0].prevK())))
+ line2.WriteString(fmt.Sprintf("H%6d(%c)\t", m.scores[i][j][1].val(), dir(m.scores[i][j][1].prevK())))
+ }
+ buf.WriteString(line1.String())
+ buf.WriteString("\n")
+ buf.WriteString(line2.String())
+ buf.WriteString("\n")
+ buf.WriteString(separator.String())
+ buf.WriteString("\n")
+ }
+
+ return buf.String()
+}
+
+func dir(prevK int) rune {
+ if prevK == 0 {
+ return 'M'
+ }
+ return 'H'
+}
+
+func (m *Matcher) poorMatch() bool {
+ if len(m.pattern) < 2 {
+ return false
+ }
+
+ i, j := m.lastCandidateLen, len(m.pattern)
+ k := m.bestK(i, j)
+
+ var counter, len int
+ for i > 0 {
+ take := (k == 1)
+ k = m.scores[i][j][k].prevK()
+ if take {
+ len++
+ if k == 0 && len < 3 && m.roles[i-1] == RTail {
+ // Short match in the middle of a word
+ counter++
+ if counter > 1 {
+ return true
+ }
+ }
+ j--
+ } else {
+ len = 0
+ }
+ i--
+ }
+ return false
+}
golang.org/x/sys/internal/unsafeheader
golang.org/x/sys/unix
golang.org/x/sys/windows
-# golang.org/x/tools v0.0.0-20200616133436-c1934b75d054
+# golang.org/x/tools v0.0.0-20200901153117-6e59e24738da
## explicit
golang.org/x/tools/go/analysis
golang.org/x/tools/go/analysis/internal/analysisflags
golang.org/x/tools/go/types/objectpath
golang.org/x/tools/go/types/typeutil
golang.org/x/tools/internal/analysisinternal
+golang.org/x/tools/internal/lsp/fuzzy
# golang.org/x/xerrors v0.0.0-20200806184451-1a77d5e9f316
## explicit
golang.org/x/xerrors