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-rw-r--r--vendor/golang.org/x/tools/go/ast/astutil/enclosing.go627
-rw-r--r--vendor/golang.org/x/tools/go/ast/astutil/imports.go471
-rw-r--r--vendor/golang.org/x/tools/go/ast/astutil/rewrite.go477
-rw-r--r--vendor/golang.org/x/tools/go/ast/astutil/util.go14
-rw-r--r--vendor/golang.org/x/tools/go/buildutil/allpackages.go198
-rw-r--r--vendor/golang.org/x/tools/go/buildutil/fakecontext.go109
-rw-r--r--vendor/golang.org/x/tools/go/buildutil/overlay.go103
-rw-r--r--vendor/golang.org/x/tools/go/buildutil/tags.go75
-rw-r--r--vendor/golang.org/x/tools/go/buildutil/util.go212
-rw-r--r--vendor/golang.org/x/tools/go/internal/cgo/cgo.go220
-rw-r--r--vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go39
-rw-r--r--vendor/golang.org/x/tools/go/loader/doc.go205
-rw-r--r--vendor/golang.org/x/tools/go/loader/loader.go1078
-rw-r--r--vendor/golang.org/x/tools/go/loader/util.go124
14 files changed, 3952 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go
new file mode 100644
index 00000000..6b7052b8
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go
@@ -0,0 +1,627 @@
+// 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 astutil
+
+// This file defines utilities for working with source positions.
+
+import (
+ "fmt"
+ "go/ast"
+ "go/token"
+ "sort"
+)
+
+// PathEnclosingInterval returns the node that encloses the source
+// interval [start, end), and all its ancestors up to the AST root.
+//
+// The definition of "enclosing" used by this function considers
+// additional whitespace abutting a node to be enclosed by it.
+// In this example:
+//
+// z := x + y // add them
+// <-A->
+// <----B----->
+//
+// the ast.BinaryExpr(+) node is considered to enclose interval B
+// even though its [Pos()..End()) is actually only interval A.
+// This behaviour makes user interfaces more tolerant of imperfect
+// input.
+//
+// This function treats tokens as nodes, though they are not included
+// in the result. e.g. PathEnclosingInterval("+") returns the
+// enclosing ast.BinaryExpr("x + y").
+//
+// If start==end, the 1-char interval following start is used instead.
+//
+// The 'exact' result is true if the interval contains only path[0]
+// and perhaps some adjacent whitespace. It is false if the interval
+// overlaps multiple children of path[0], or if it contains only
+// interior whitespace of path[0].
+// In this example:
+//
+// z := x + y // add them
+// <--C--> <---E-->
+// ^
+// D
+//
+// intervals C, D and E are inexact. C is contained by the
+// z-assignment statement, because it spans three of its children (:=,
+// x, +). So too is the 1-char interval D, because it contains only
+// interior whitespace of the assignment. E is considered interior
+// whitespace of the BlockStmt containing the assignment.
+//
+// Precondition: [start, end) both lie within the same file as root.
+// TODO(adonovan): return (nil, false) in this case and remove precond.
+// Requires FileSet; see loader.tokenFileContainsPos.
+//
+// Postcondition: path is never nil; it always contains at least 'root'.
+//
+func PathEnclosingInterval(root *ast.File, start, end token.Pos) (path []ast.Node, exact bool) {
+ // fmt.Printf("EnclosingInterval %d %d\n", start, end) // debugging
+
+ // Precondition: node.[Pos..End) and adjoining whitespace contain [start, end).
+ var visit func(node ast.Node) bool
+ visit = func(node ast.Node) bool {
+ path = append(path, node)
+
+ nodePos := node.Pos()
+ nodeEnd := node.End()
+
+ // fmt.Printf("visit(%T, %d, %d)\n", node, nodePos, nodeEnd) // debugging
+
+ // Intersect [start, end) with interval of node.
+ if start < nodePos {
+ start = nodePos
+ }
+ if end > nodeEnd {
+ end = nodeEnd
+ }
+
+ // Find sole child that contains [start, end).
+ children := childrenOf(node)
+ l := len(children)
+ for i, child := range children {
+ // [childPos, childEnd) is unaugmented interval of child.
+ childPos := child.Pos()
+ childEnd := child.End()
+
+ // [augPos, augEnd) is whitespace-augmented interval of child.
+ augPos := childPos
+ augEnd := childEnd
+ if i > 0 {
+ augPos = children[i-1].End() // start of preceding whitespace
+ }
+ if i < l-1 {
+ nextChildPos := children[i+1].Pos()
+ // Does [start, end) lie between child and next child?
+ if start >= augEnd && end <= nextChildPos {
+ return false // inexact match
+ }
+ augEnd = nextChildPos // end of following whitespace
+ }
+
+ // fmt.Printf("\tchild %d: [%d..%d)\tcontains interval [%d..%d)?\n",
+ // i, augPos, augEnd, start, end) // debugging
+
+ // Does augmented child strictly contain [start, end)?
+ if augPos <= start && end <= augEnd {
+ _, isToken := child.(tokenNode)
+ return isToken || visit(child)
+ }
+
+ // Does [start, end) overlap multiple children?
+ // i.e. left-augmented child contains start
+ // but LR-augmented child does not contain end.
+ if start < childEnd && end > augEnd {
+ break
+ }
+ }
+
+ // No single child contained [start, end),
+ // so node is the result. Is it exact?
+
+ // (It's tempting to put this condition before the
+ // child loop, but it gives the wrong result in the
+ // case where a node (e.g. ExprStmt) and its sole
+ // child have equal intervals.)
+ if start == nodePos && end == nodeEnd {
+ return true // exact match
+ }
+
+ return false // inexact: overlaps multiple children
+ }
+
+ if start > end {
+ start, end = end, start
+ }
+
+ if start < root.End() && end > root.Pos() {
+ if start == end {
+ end = start + 1 // empty interval => interval of size 1
+ }
+ exact = visit(root)
+
+ // Reverse the path:
+ for i, l := 0, len(path); i < l/2; i++ {
+ path[i], path[l-1-i] = path[l-1-i], path[i]
+ }
+ } else {
+ // Selection lies within whitespace preceding the
+ // first (or following the last) declaration in the file.
+ // The result nonetheless always includes the ast.File.
+ path = append(path, root)
+ }
+
+ return
+}
+
+// tokenNode is a dummy implementation of ast.Node for a single token.
+// They are used transiently by PathEnclosingInterval but never escape
+// this package.
+//
+type tokenNode struct {
+ pos token.Pos
+ end token.Pos
+}
+
+func (n tokenNode) Pos() token.Pos {
+ return n.pos
+}
+
+func (n tokenNode) End() token.Pos {
+ return n.end
+}
+
+func tok(pos token.Pos, len int) ast.Node {
+ return tokenNode{pos, pos + token.Pos(len)}
+}
+
+// childrenOf returns the direct non-nil children of ast.Node n.
+// It may include fake ast.Node implementations for bare tokens.
+// it is not safe to call (e.g.) ast.Walk on such nodes.
+//
+func childrenOf(n ast.Node) []ast.Node {
+ var children []ast.Node
+
+ // First add nodes for all true subtrees.
+ ast.Inspect(n, func(node ast.Node) bool {
+ if node == n { // push n
+ return true // recur
+ }
+ if node != nil { // push child
+ children = append(children, node)
+ }
+ return false // no recursion
+ })
+
+ // Then add fake Nodes for bare tokens.
+ switch n := n.(type) {
+ case *ast.ArrayType:
+ children = append(children,
+ tok(n.Lbrack, len("[")),
+ tok(n.Elt.End(), len("]")))
+
+ case *ast.AssignStmt:
+ children = append(children,
+ tok(n.TokPos, len(n.Tok.String())))
+
+ case *ast.BasicLit:
+ children = append(children,
+ tok(n.ValuePos, len(n.Value)))
+
+ case *ast.BinaryExpr:
+ children = append(children, tok(n.OpPos, len(n.Op.String())))
+
+ case *ast.BlockStmt:
+ children = append(children,
+ tok(n.Lbrace, len("{")),
+ tok(n.Rbrace, len("}")))
+
+ case *ast.BranchStmt:
+ children = append(children,
+ tok(n.TokPos, len(n.Tok.String())))
+
+ case *ast.CallExpr:
+ children = append(children,
+ tok(n.Lparen, len("(")),
+ tok(n.Rparen, len(")")))
+ if n.Ellipsis != 0 {
+ children = append(children, tok(n.Ellipsis, len("...")))
+ }
+
+ case *ast.CaseClause:
+ if n.List == nil {
+ children = append(children,
+ tok(n.Case, len("default")))
+ } else {
+ children = append(children,
+ tok(n.Case, len("case")))
+ }
+ children = append(children, tok(n.Colon, len(":")))
+
+ case *ast.ChanType:
+ switch n.Dir {
+ case ast.RECV:
+ children = append(children, tok(n.Begin, len("<-chan")))
+ case ast.SEND:
+ children = append(children, tok(n.Begin, len("chan<-")))
+ case ast.RECV | ast.SEND:
+ children = append(children, tok(n.Begin, len("chan")))
+ }
+
+ case *ast.CommClause:
+ if n.Comm == nil {
+ children = append(children,
+ tok(n.Case, len("default")))
+ } else {
+ children = append(children,
+ tok(n.Case, len("case")))
+ }
+ children = append(children, tok(n.Colon, len(":")))
+
+ case *ast.Comment:
+ // nop
+
+ case *ast.CommentGroup:
+ // nop
+
+ case *ast.CompositeLit:
+ children = append(children,
+ tok(n.Lbrace, len("{")),
+ tok(n.Rbrace, len("{")))
+
+ case *ast.DeclStmt:
+ // nop
+
+ case *ast.DeferStmt:
+ children = append(children,
+ tok(n.Defer, len("defer")))
+
+ case *ast.Ellipsis:
+ children = append(children,
+ tok(n.Ellipsis, len("...")))
+
+ case *ast.EmptyStmt:
+ // nop
+
+ case *ast.ExprStmt:
+ // nop
+
+ case *ast.Field:
+ // TODO(adonovan): Field.{Doc,Comment,Tag}?
+
+ case *ast.FieldList:
+ children = append(children,
+ tok(n.Opening, len("(")),
+ tok(n.Closing, len(")")))
+
+ case *ast.File:
+ // TODO test: Doc
+ children = append(children,
+ tok(n.Package, len("package")))
+
+ case *ast.ForStmt:
+ children = append(children,
+ tok(n.For, len("for")))
+
+ case *ast.FuncDecl:
+ // TODO(adonovan): FuncDecl.Comment?
+
+ // Uniquely, FuncDecl breaks the invariant that
+ // preorder traversal yields tokens in lexical order:
+ // in fact, FuncDecl.Recv precedes FuncDecl.Type.Func.
+ //
+ // As a workaround, we inline the case for FuncType
+ // here and order things correctly.
+ //
+ children = nil // discard ast.Walk(FuncDecl) info subtrees
+ children = append(children, tok(n.Type.Func, len("func")))
+ if n.Recv != nil {
+ children = append(children, n.Recv)
+ }
+ children = append(children, n.Name)
+ if n.Type.Params != nil {
+ children = append(children, n.Type.Params)
+ }
+ if n.Type.Results != nil {
+ children = append(children, n.Type.Results)
+ }
+ if n.Body != nil {
+ children = append(children, n.Body)
+ }
+
+ case *ast.FuncLit:
+ // nop
+
+ case *ast.FuncType:
+ if n.Func != 0 {
+ children = append(children,
+ tok(n.Func, len("func")))
+ }
+
+ case *ast.GenDecl:
+ children = append(children,
+ tok(n.TokPos, len(n.Tok.String())))
+ if n.Lparen != 0 {
+ children = append(children,
+ tok(n.Lparen, len("(")),
+ tok(n.Rparen, len(")")))
+ }
+
+ case *ast.GoStmt:
+ children = append(children,
+ tok(n.Go, len("go")))
+
+ case *ast.Ident:
+ children = append(children,
+ tok(n.NamePos, len(n.Name)))
+
+ case *ast.IfStmt:
+ children = append(children,
+ tok(n.If, len("if")))
+
+ case *ast.ImportSpec:
+ // TODO(adonovan): ImportSpec.{Doc,EndPos}?
+
+ case *ast.IncDecStmt:
+ children = append(children,
+ tok(n.TokPos, len(n.Tok.String())))
+
+ case *ast.IndexExpr:
+ children = append(children,
+ tok(n.Lbrack, len("{")),
+ tok(n.Rbrack, len("}")))
+
+ case *ast.InterfaceType:
+ children = append(children,
+ tok(n.Interface, len("interface")))
+
+ case *ast.KeyValueExpr:
+ children = append(children,
+ tok(n.Colon, len(":")))
+
+ case *ast.LabeledStmt:
+ children = append(children,
+ tok(n.Colon, len(":")))
+
+ case *ast.MapType:
+ children = append(children,
+ tok(n.Map, len("map")))
+
+ case *ast.ParenExpr:
+ children = append(children,
+ tok(n.Lparen, len("(")),
+ tok(n.Rparen, len(")")))
+
+ case *ast.RangeStmt:
+ children = append(children,
+ tok(n.For, len("for")),
+ tok(n.TokPos, len(n.Tok.String())))
+
+ case *ast.ReturnStmt:
+ children = append(children,
+ tok(n.Return, len("return")))
+
+ case *ast.SelectStmt:
+ children = append(children,
+ tok(n.Select, len("select")))
+
+ case *ast.SelectorExpr:
+ // nop
+
+ case *ast.SendStmt:
+ children = append(children,
+ tok(n.Arrow, len("<-")))
+
+ case *ast.SliceExpr:
+ children = append(children,
+ tok(n.Lbrack, len("[")),
+ tok(n.Rbrack, len("]")))
+
+ case *ast.StarExpr:
+ children = append(children, tok(n.Star, len("*")))
+
+ case *ast.StructType:
+ children = append(children, tok(n.Struct, len("struct")))
+
+ case *ast.SwitchStmt:
+ children = append(children, tok(n.Switch, len("switch")))
+
+ case *ast.TypeAssertExpr:
+ children = append(children,
+ tok(n.Lparen-1, len(".")),
+ tok(n.Lparen, len("(")),
+ tok(n.Rparen, len(")")))
+
+ case *ast.TypeSpec:
+ // TODO(adonovan): TypeSpec.{Doc,Comment}?
+
+ case *ast.TypeSwitchStmt:
+ children = append(children, tok(n.Switch, len("switch")))
+
+ case *ast.UnaryExpr:
+ children = append(children, tok(n.OpPos, len(n.Op.String())))
+
+ case *ast.ValueSpec:
+ // TODO(adonovan): ValueSpec.{Doc,Comment}?
+
+ case *ast.BadDecl, *ast.BadExpr, *ast.BadStmt:
+ // nop
+ }
+
+ // TODO(adonovan): opt: merge the logic of ast.Inspect() into
+ // the switch above so we can make interleaved callbacks for
+ // both Nodes and Tokens in the right order and avoid the need
+ // to sort.
+ sort.Sort(byPos(children))
+
+ return children
+}
+
+type byPos []ast.Node
+
+func (sl byPos) Len() int {
+ return len(sl)
+}
+func (sl byPos) Less(i, j int) bool {
+ return sl[i].Pos() < sl[j].Pos()
+}
+func (sl byPos) Swap(i, j int) {
+ sl[i], sl[j] = sl[j], sl[i]
+}
+
+// NodeDescription returns a description of the concrete type of n suitable
+// for a user interface.
+//
+// TODO(adonovan): in some cases (e.g. Field, FieldList, Ident,
+// StarExpr) we could be much more specific given the path to the AST
+// root. Perhaps we should do that.
+//
+func NodeDescription(n ast.Node) string {
+ switch n := n.(type) {
+ case *ast.ArrayType:
+ return "array type"
+ case *ast.AssignStmt:
+ return "assignment"
+ case *ast.BadDecl:
+ return "bad declaration"
+ case *ast.BadExpr:
+ return "bad expression"
+ case *ast.BadStmt:
+ return "bad statement"
+ case *ast.BasicLit:
+ return "basic literal"
+ case *ast.BinaryExpr:
+ return fmt.Sprintf("binary %s operation", n.Op)
+ case *ast.BlockStmt:
+ return "block"
+ case *ast.BranchStmt:
+ switch n.Tok {
+ case token.BREAK:
+ return "break statement"
+ case token.CONTINUE:
+ return "continue statement"
+ case token.GOTO:
+ return "goto statement"
+ case token.FALLTHROUGH:
+ return "fall-through statement"
+ }
+ case *ast.CallExpr:
+ if len(n.Args) == 1 && !n.Ellipsis.IsValid() {
+ return "function call (or conversion)"
+ }
+ return "function call"
+ case *ast.CaseClause:
+ return "case clause"
+ case *ast.ChanType:
+ return "channel type"
+ case *ast.CommClause:
+ return "communication clause"
+ case *ast.Comment:
+ return "comment"
+ case *ast.CommentGroup:
+ return "comment group"
+ case *ast.CompositeLit:
+ return "composite literal"
+ case *ast.DeclStmt:
+ return NodeDescription(n.Decl) + " statement"
+ case *ast.DeferStmt:
+ return "defer statement"
+ case *ast.Ellipsis:
+ return "ellipsis"
+ case *ast.EmptyStmt:
+ return "empty statement"
+ case *ast.ExprStmt:
+ return "expression statement"
+ case *ast.Field:
+ // Can be any of these:
+ // struct {x, y int} -- struct field(s)
+ // struct {T} -- anon struct field
+ // interface {I} -- interface embedding
+ // interface {f()} -- interface method
+ // func (A) func(B) C -- receiver, param(s), result(s)
+ return "field/method/parameter"
+ case *ast.FieldList:
+ return "field/method/parameter list"
+ case *ast.File:
+ return "source file"
+ case *ast.ForStmt:
+ return "for loop"
+ case *ast.FuncDecl:
+ return "function declaration"
+ case *ast.FuncLit:
+ return "function literal"
+ case *ast.FuncType:
+ return "function type"
+ case *ast.GenDecl:
+ switch n.Tok {
+ case token.IMPORT:
+ return "import declaration"
+ case token.CONST:
+ return "constant declaration"
+ case token.TYPE:
+ return "type declaration"
+ case token.VAR:
+ return "variable declaration"
+ }
+ case *ast.GoStmt:
+ return "go statement"
+ case *ast.Ident:
+ return "identifier"
+ case *ast.IfStmt:
+ return "if statement"
+ case *ast.ImportSpec:
+ return "import specification"
+ case *ast.IncDecStmt:
+ if n.Tok == token.INC {
+ return "increment statement"
+ }
+ return "decrement statement"
+ case *ast.IndexExpr:
+ return "index expression"
+ case *ast.InterfaceType:
+ return "interface type"
+ case *ast.KeyValueExpr:
+ return "key/value association"
+ case *ast.LabeledStmt:
+ return "statement label"
+ case *ast.MapType:
+ return "map type"
+ case *ast.Package:
+ return "package"
+ case *ast.ParenExpr:
+ return "parenthesized " + NodeDescription(n.X)
+ case *ast.RangeStmt:
+ return "range loop"
+ case *ast.ReturnStmt:
+ return "return statement"
+ case *ast.SelectStmt:
+ return "select statement"
+ case *ast.SelectorExpr:
+ return "selector"
+ case *ast.SendStmt:
+ return "channel send"
+ case *ast.SliceExpr:
+ return "slice expression"
+ case *ast.StarExpr:
+ return "*-operation" // load/store expr or pointer type
+ case *ast.StructType:
+ return "struct type"
+ case *ast.SwitchStmt:
+ return "switch statement"
+ case *ast.TypeAssertExpr:
+ return "type assertion"
+ case *ast.TypeSpec:
+ return "type specification"
+ case *ast.TypeSwitchStmt:
+ return "type switch"
+ case *ast.UnaryExpr:
+ return fmt.Sprintf("unary %s operation", n.Op)
+ case *ast.ValueSpec:
+ return "value specification"
+
+ }
+ panic(fmt.Sprintf("unexpected node type: %T", n))
+}
diff --git a/vendor/golang.org/x/tools/go/ast/astutil/imports.go b/vendor/golang.org/x/tools/go/ast/astutil/imports.go
new file mode 100644
index 00000000..04ad6795
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/ast/astutil/imports.go
@@ -0,0 +1,471 @@
+// 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 astutil contains common utilities for working with the Go AST.
+package astutil // import "golang.org/x/tools/go/ast/astutil"
+
+import (
+ "fmt"
+ "go/ast"
+ "go/token"
+ "strconv"
+ "strings"
+)
+
+// AddImport adds the import path to the file f, if absent.
+func AddImport(fset *token.FileSet, f *ast.File, ipath string) (added bool) {
+ return AddNamedImport(fset, f, "", ipath)
+}
+
+// AddNamedImport adds the import path to the file f, if absent.
+// If name is not empty, it is used to rename the import.
+//
+// For example, calling
+// AddNamedImport(fset, f, "pathpkg", "path")
+// adds
+// import pathpkg "path"
+func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added bool) {
+ if imports(f, ipath) {
+ return false
+ }
+
+ newImport := &ast.ImportSpec{
+ Path: &ast.BasicLit{
+ Kind: token.STRING,
+ Value: strconv.Quote(ipath),
+ },
+ }
+ if name != "" {
+ newImport.Name = &ast.Ident{Name: name}
+ }
+
+ // Find an import decl to add to.
+ // The goal is to find an existing import
+ // whose import path has the longest shared
+ // prefix with ipath.
+ var (
+ bestMatch = -1 // length of longest shared prefix
+ lastImport = -1 // index in f.Decls of the file's final import decl
+ impDecl *ast.GenDecl // import decl containing the best match
+ impIndex = -1 // spec index in impDecl containing the best match
+
+ isThirdPartyPath = isThirdParty(ipath)
+ )
+ for i, decl := range f.Decls {
+ gen, ok := decl.(*ast.GenDecl)
+ if ok && gen.Tok == token.IMPORT {
+ lastImport = i
+ // Do not add to import "C", to avoid disrupting the
+ // association with its doc comment, breaking cgo.
+ if declImports(gen, "C") {
+ continue
+ }
+
+ // Match an empty import decl if that's all that is available.
+ if len(gen.Specs) == 0 && bestMatch == -1 {
+ impDecl = gen
+ }
+
+ // Compute longest shared prefix with imports in this group and find best
+ // matched import spec.
+ // 1. Always prefer import spec with longest shared prefix.
+ // 2. While match length is 0,
+ // - for stdlib package: prefer first import spec.
+ // - for third party package: prefer first third party import spec.
+ // We cannot use last import spec as best match for third party package
+ // because grouped imports are usually placed last by goimports -local
+ // flag.
+ // See issue #19190.
+ seenAnyThirdParty := false
+ for j, spec := range gen.Specs {
+ impspec := spec.(*ast.ImportSpec)
+ p := importPath(impspec)
+ n := matchLen(p, ipath)
+ if n > bestMatch || (bestMatch == 0 && !seenAnyThirdParty && isThirdPartyPath) {
+ bestMatch = n
+ impDecl = gen
+ impIndex = j
+ }
+ seenAnyThirdParty = seenAnyThirdParty || isThirdParty(p)
+ }
+ }
+ }
+
+ // If no import decl found, add one after the last import.
+ if impDecl == nil {
+ impDecl = &ast.GenDecl{
+ Tok: token.IMPORT,
+ }
+ if lastImport >= 0 {
+ impDecl.TokPos = f.Decls[lastImport].End()
+ } else {
+ // There are no existing imports.
+ // Our new import, preceded by a blank line, goes after the package declaration
+ // and after the comment, if any, that starts on the same line as the
+ // package declaration.
+ impDecl.TokPos = f.Package
+
+ file := fset.File(f.Package)
+ pkgLine := file.Line(f.Package)
+ for _, c := range f.Comments {
+ if file.Line(c.Pos()) > pkgLine {
+ break
+ }
+ // +2 for a blank line
+ impDecl.TokPos = c.End() + 2
+ }
+ }
+ f.Decls = append(f.Decls, nil)
+ copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:])
+ f.Decls[lastImport+1] = impDecl
+ }
+
+ // Insert new import at insertAt.
+ insertAt := 0
+ if impIndex >= 0 {
+ // insert after the found import
+ insertAt = impIndex + 1
+ }
+ impDecl.Specs = append(impDecl.Specs, nil)
+ copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:])
+ impDecl.Specs[insertAt] = newImport
+ pos := impDecl.Pos()
+ if insertAt > 0 {
+ // If there is a comment after an existing import, preserve the comment
+ // position by adding the new import after the comment.
+ if spec, ok := impDecl.Specs[insertAt-1].(*ast.ImportSpec); ok && spec.Comment != nil {
+ pos = spec.Comment.End()
+ } else {
+ // Assign same position as the previous import,
+ // so that the sorter sees it as being in the same block.
+ pos = impDecl.Specs[insertAt-1].Pos()
+ }
+ }
+ if newImport.Name != nil {
+ newImport.Name.NamePos = pos
+ }
+ newImport.Path.ValuePos = pos
+ newImport.EndPos = pos
+
+ // Clean up parens. impDecl contains at least one spec.
+ if len(impDecl.Specs) == 1 {
+ // Remove unneeded parens.
+ impDecl.Lparen = token.NoPos
+ } else if !impDecl.Lparen.IsValid() {
+ // impDecl needs parens added.
+ impDecl.Lparen = impDecl.Specs[0].Pos()
+ }
+
+ f.Imports = append(f.Imports, newImport)
+
+ if len(f.Decls) <= 1 {
+ return true
+ }
+
+ // Merge all the import declarations into the first one.
+ var first *ast.GenDecl
+ for i := 0; i < len(f.Decls); i++ {
+ decl := f.Decls[i]
+ gen, ok := decl.(*ast.GenDecl)
+ if !ok || gen.Tok != token.IMPORT || declImports(gen, "C") {
+ continue
+ }
+ if first == nil {
+ first = gen
+ continue // Don't touch the first one.
+ }
+ // We now know there is more than one package in this import
+ // declaration. Ensure that it ends up parenthesized.
+ first.Lparen = first.Pos()
+ // Move the imports of the other import declaration to the first one.
+ for _, spec := range gen.Specs {
+ spec.(*ast.ImportSpec).Path.ValuePos = first.Pos()
+ first.Specs = append(first.Specs, spec)
+ }
+ f.Decls = append(f.Decls[:i], f.Decls[i+1:]...)
+ i--
+ }
+
+ return true
+}
+
+func isThirdParty(importPath string) bool {
+ // Third party package import path usually contains "." (".com", ".org", ...)
+ // This logic is taken from golang.org/x/tools/imports package.
+ return strings.Contains(importPath, ".")
+}
+
+// DeleteImport deletes the import path from the file f, if present.
+func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) {
+ return DeleteNamedImport(fset, f, "", path)
+}
+
+// DeleteNamedImport deletes the import with the given name and path from the file f, if present.
+func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (deleted bool) {
+ var delspecs []*ast.ImportSpec
+ var delcomments []*ast.CommentGroup
+
+ // Find the import nodes that import path, if any.
+ for i := 0; i < len(f.Decls); i++ {
+ decl := f.Decls[i]
+ gen, ok := decl.(*ast.GenDecl)
+ if !ok || gen.Tok != token.IMPORT {
+ continue
+ }
+ for j := 0; j < len(gen.Specs); j++ {
+ spec := gen.Specs[j]
+ impspec := spec.(*ast.ImportSpec)
+ if impspec.Name == nil && name != "" {
+ continue
+ }
+ if impspec.Name != nil && impspec.Name.Name != name {
+ continue
+ }
+ if importPath(impspec) != path {
+ continue
+ }
+
+ // We found an import spec that imports path.
+ // Delete it.
+ delspecs = append(delspecs, impspec)
+ deleted = true
+ copy(gen.Specs[j:], gen.Specs[j+1:])
+ gen.Specs = gen.Specs[:len(gen.Specs)-1]
+
+ // If this was the last import spec in this decl,
+ // delete the decl, too.
+ if len(gen.Specs) == 0 {
+ copy(f.Decls[i:], f.Decls[i+1:])
+ f.Decls = f.Decls[:len(f.Decls)-1]
+ i--
+ break
+ } else if len(gen.Specs) == 1 {
+ if impspec.Doc != nil {
+ delcomments = append(delcomments, impspec.Doc)
+ }
+ if impspec.Comment != nil {
+ delcomments = append(delcomments, impspec.Comment)
+ }
+ for _, cg := range f.Comments {
+ // Found comment on the same line as the import spec.
+ if cg.End() < impspec.Pos() && fset.Position(cg.End()).Line == fset.Position(impspec.Pos()).Line {
+ delcomments = append(delcomments, cg)
+ break
+ }
+ }
+
+ spec := gen.Specs[0].(*ast.ImportSpec)
+
+ // Move the documentation right after the import decl.
+ if spec.Doc != nil {
+ for fset.Position(gen.TokPos).Line+1 < fset.Position(spec.Doc.Pos()).Line {
+ fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line)
+ }
+ }
+ for _, cg := range f.Comments {
+ if cg.End() < spec.Pos() && fset.Position(cg.End()).Line == fset.Position(spec.Pos()).Line {
+ for fset.Position(gen.TokPos).Line+1 < fset.Position(spec.Pos()).Line {
+ fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line)
+ }
+ break
+ }
+ }
+ }
+ if j > 0 {
+ lastImpspec := gen.Specs[j-1].(*ast.ImportSpec)
+ lastLine := fset.Position(lastImpspec.Path.ValuePos).Line
+ line := fset.Position(impspec.Path.ValuePos).Line
+
+ // We deleted an entry but now there may be
+ // a blank line-sized hole where the import was.
+ if line-lastLine > 1 {
+ // There was a blank line immediately preceding the deleted import,
+ // so there's no need to close the hole.
+ // Do nothing.
+ } else if line != fset.File(gen.Rparen).LineCount() {
+ // There was no blank line. Close the hole.
+ fset.File(gen.Rparen).MergeLine(line)
+ }
+ }
+ j--
+ }
+ }
+
+ // Delete imports from f.Imports.
+ for i := 0; i < len(f.Imports); i++ {
+ imp := f.Imports[i]
+ for j, del := range delspecs {
+ if imp == del {
+ copy(f.Imports[i:], f.Imports[i+1:])
+ f.Imports = f.Imports[:len(f.Imports)-1]
+ copy(delspecs[j:], delspecs[j+1:])
+ delspecs = delspecs[:len(delspecs)-1]
+ i--
+ break
+ }
+ }
+ }
+
+ // Delete comments from f.Comments.
+ for i := 0; i < len(f.Comments); i++ {
+ cg := f.Comments[i]
+ for j, del := range delcomments {
+ if cg == del {
+ copy(f.Comments[i:], f.Comments[i+1:])
+ f.Comments = f.Comments[:len(f.Comments)-1]
+ copy(delcomments[j:], delcomments[j+1:])
+ delcomments = delcomments[:len(delcomments)-1]
+ i--
+ break
+ }
+ }
+ }
+
+ if len(delspecs) > 0 {
+ panic(fmt.Sprintf("deleted specs from Decls but not Imports: %v", delspecs))
+ }
+
+ return
+}
+
+// RewriteImport rewrites any import of path oldPath to path newPath.
+func RewriteImport(fset *token.FileSet, f *ast.File, oldPath, newPath string) (rewrote bool) {
+ for _, imp := range f.Imports {
+ if importPath(imp) == oldPath {
+ rewrote = true
+ // record old End, because the default is to compute
+ // it using the length of imp.Path.Value.
+ imp.EndPos = imp.End()
+ imp.Path.Value = strconv.Quote(newPath)
+ }
+ }
+ return
+}
+
+// UsesImport reports whether a given import is used.
+func UsesImport(f *ast.File, path string) (used bool) {
+ spec := importSpec(f, path)
+ if spec == nil {
+ return
+ }
+
+ name := spec.Name.String()
+ switch name {
+ case "<nil>":
+ // If the package name is not explicitly specified,
+ // make an educated guess. This is not guaranteed to be correct.
+ lastSlash := strings.LastIndex(path, "/")
+ if lastSlash == -1 {
+ name = path
+ } else {
+ name = path[lastSlash+1:]
+ }
+ case "_", ".":
+ // Not sure if this import is used - err on the side of caution.
+ return true
+ }
+
+ ast.Walk(visitFn(func(n ast.Node) {
+ sel, ok := n.(*ast.SelectorExpr)
+ if ok && isTopName(sel.X, name) {
+ used = true
+ }
+ }), f)
+
+ return
+}
+
+type visitFn func(node ast.Node)
+
+func (fn visitFn) Visit(node ast.Node) ast.Visitor {
+ fn(node)
+ return fn
+}
+
+// imports returns true if f imports path.
+func imports(f *ast.File, path string) bool {
+ return importSpec(f, path) != nil
+}
+
+// importSpec returns the import spec if f imports path,
+// or nil otherwise.
+func importSpec(f *ast.File, path string) *ast.ImportSpec {
+ for _, s := range f.Imports {
+ if importPath(s) == path {
+ return s
+ }
+ }
+ return nil
+}
+
+// importPath returns the unquoted import path of s,
+// or "" if the path is not properly quoted.
+func importPath(s *ast.ImportSpec) string {
+ t, err := strconv.Unquote(s.Path.Value)
+ if err == nil {
+ return t
+ }
+ return ""
+}
+
+// declImports reports whether gen contains an import of path.
+func declImports(gen *ast.GenDecl, path string) bool {
+ if gen.Tok != token.IMPORT {
+ return false
+ }
+ for _, spec := range gen.Specs {
+ impspec := spec.(*ast.ImportSpec)
+ if importPath(impspec) == path {
+ return true
+ }
+ }
+ return false
+}
+
+// matchLen returns the length of the longest path segment prefix shared by x and y.
+func matchLen(x, y string) int {
+ n := 0
+ for i := 0; i < len(x) && i < len(y) && x[i] == y[i]; i++ {
+ if x[i] == '/' {
+ n++
+ }
+ }
+ return n
+}
+
+// isTopName returns true if n is a top-level unresolved identifier with the given name.
+func isTopName(n ast.Expr, name string) bool {
+ id, ok := n.(*ast.Ident)
+ return ok && id.Name == name && id.Obj == nil
+}
+
+// Imports returns the file imports grouped by paragraph.
+func Imports(fset *token.FileSet, f *ast.File) [][]*ast.ImportSpec {
+ var groups [][]*ast.ImportSpec
+
+ for _, decl := range f.Decls {
+ genDecl, ok := decl.(*ast.GenDecl)
+ if !ok || genDecl.Tok != token.IMPORT {
+ break
+ }
+
+ group := []*ast.ImportSpec{}
+
+ var lastLine int
+ for _, spec := range genDecl.Specs {
+ importSpec := spec.(*ast.ImportSpec)
+ pos := importSpec.Path.ValuePos
+ line := fset.Position(pos).Line
+ if lastLine > 0 && pos > 0 && line-lastLine > 1 {
+ groups = append(groups, group)
+ group = []*ast.ImportSpec{}
+ }
+ group = append(group, importSpec)
+ lastLine = line
+ }
+ groups = append(groups, group)
+ }
+
+ return groups
+}
diff --git a/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go
new file mode 100644
index 00000000..cf72ea99
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go
@@ -0,0 +1,477 @@
+// Copyright 2017 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 astutil
+
+import (
+ "fmt"
+ "go/ast"
+ "reflect"
+ "sort"
+)
+
+// An ApplyFunc is invoked by Apply for each node n, even if n is nil,
+// before and/or after the node's children, using a Cursor describing
+// the current node and providing operations on it.
+//
+// The return value of ApplyFunc controls the syntax tree traversal.
+// See Apply for details.
+type ApplyFunc func(*Cursor) bool
+
+// Apply traverses a syntax tree recursively, starting with root,
+// and calling pre and post for each node as described below.
+// Apply returns the syntax tree, possibly modified.
+//
+// If pre is not nil, it is called for each node before the node's
+// children are traversed (pre-order). If pre returns false, no
+// children are traversed, and post is not called for that node.
+//
+// If post is not nil, and a prior call of pre didn't return false,
+// post is called for each node after its children are traversed
+// (post-order). If post returns false, traversal is terminated and
+// Apply returns immediately.
+//
+// Only fields that refer to AST nodes are considered children;
+// i.e., token.Pos, Scopes, Objects, and fields of basic types
+// (strings, etc.) are ignored.
+//
+// Children are traversed in the order in which they appear in the
+// respective node's struct definition. A package's files are
+// traversed in the filenames' alphabetical order.
+//
+func Apply(root ast.Node, pre, post ApplyFunc) (result ast.Node) {
+ parent := &struct{ ast.Node }{root}
+ defer func() {
+ if r := recover(); r != nil && r != abort {
+ panic(r)
+ }
+ result = parent.Node
+ }()
+ a := &application{pre: pre, post: post}
+ a.apply(parent, "Node", nil, root)
+ return
+}
+
+var abort = new(int) // singleton, to signal termination of Apply
+
+// A Cursor describes a node encountered during Apply.
+// Information about the node and its parent is available
+// from the Node, Parent, Name, and Index methods.
+//
+// If p is a variable of type and value of the current parent node
+// c.Parent(), and f is the field identifier with name c.Name(),
+// the following invariants hold:
+//
+// p.f == c.Node() if c.Index() < 0
+// p.f[c.Index()] == c.Node() if c.Index() >= 0
+//
+// The methods Replace, Delete, InsertBefore, and InsertAfter
+// can be used to change the AST without disrupting Apply.
+type Cursor struct {
+ parent ast.Node
+ name string
+ iter *iterator // valid if non-nil
+ node ast.Node
+}
+
+// Node returns the current Node.
+func (c *Cursor) Node() ast.Node { return c.node }
+
+// Parent returns the parent of the current Node.
+func (c *Cursor) Parent() ast.Node { return c.parent }
+
+// Name returns the name of the parent Node field that contains the current Node.
+// If the parent is a *ast.Package and the current Node is a *ast.File, Name returns
+// the filename for the current Node.
+func (c *Cursor) Name() string { return c.name }
+
+// Index reports the index >= 0 of the current Node in the slice of Nodes that
+// contains it, or a value < 0 if the current Node is not part of a slice.
+// The index of the current node changes if InsertBefore is called while
+// processing the current node.
+func (c *Cursor) Index() int {
+ if c.iter != nil {
+ return c.iter.index
+ }
+ return -1
+}
+
+// field returns the current node's parent field value.
+func (c *Cursor) field() reflect.Value {
+ return reflect.Indirect(reflect.ValueOf(c.parent)).FieldByName(c.name)
+}
+
+// Replace replaces the current Node with n.
+// The replacement node is not walked by Apply.
+func (c *Cursor) Replace(n ast.Node) {
+ if _, ok := c.node.(*ast.File); ok {
+ file, ok := n.(*ast.File)
+ if !ok {
+ panic("attempt to replace *ast.File with non-*ast.File")
+ }
+ c.parent.(*ast.Package).Files[c.name] = file
+ return
+ }
+
+ v := c.field()
+ if i := c.Index(); i >= 0 {
+ v = v.Index(i)
+ }
+ v.Set(reflect.ValueOf(n))
+}
+
+// Delete deletes the current Node from its containing slice.
+// If the current Node is not part of a slice, Delete panics.
+// As a special case, if the current node is a package file,
+// Delete removes it from the package's Files map.
+func (c *Cursor) Delete() {
+ if _, ok := c.node.(*ast.File); ok {
+ delete(c.parent.(*ast.Package).Files, c.name)
+ return
+ }
+
+ i := c.Index()
+ if i < 0 {
+ panic("Delete node not contained in slice")
+ }
+ v := c.field()
+ l := v.Len()
+ reflect.Copy(v.Slice(i, l), v.Slice(i+1, l))
+ v.Index(l - 1).Set(reflect.Zero(v.Type().Elem()))
+ v.SetLen(l - 1)
+ c.iter.step--
+}
+
+// InsertAfter inserts n after the current Node in its containing slice.
+// If the current Node is not part of a slice, InsertAfter panics.
+// Apply does not walk n.
+func (c *Cursor) InsertAfter(n ast.Node) {
+ i := c.Index()
+ if i < 0 {
+ panic("InsertAfter node not contained in slice")
+ }
+ v := c.field()
+ v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem())))
+ l := v.Len()
+ reflect.Copy(v.Slice(i+2, l), v.Slice(i+1, l))
+ v.Index(i + 1).Set(reflect.ValueOf(n))
+ c.iter.step++
+}
+
+// InsertBefore inserts n before the current Node in its containing slice.
+// If the current Node is not part of a slice, InsertBefore panics.
+// Apply will not walk n.
+func (c *Cursor) InsertBefore(n ast.Node) {
+ i := c.Index()
+ if i < 0 {
+ panic("InsertBefore node not contained in slice")
+ }
+ v := c.field()
+ v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem())))
+ l := v.Len()
+ reflect.Copy(v.Slice(i+1, l), v.Slice(i, l))
+ v.Index(i).Set(reflect.ValueOf(n))
+ c.iter.index++
+}
+
+// application carries all the shared data so we can pass it around cheaply.
+type application struct {
+ pre, post ApplyFunc
+ cursor Cursor
+ iter iterator
+}
+
+func (a *application) apply(parent ast.Node, name string, iter *iterator, n ast.Node) {
+ // convert typed nil into untyped nil
+ if v := reflect.ValueOf(n); v.Kind() == reflect.Ptr && v.IsNil() {
+ n = nil
+ }
+
+ // avoid heap-allocating a new cursor for each apply call; reuse a.cursor instead
+ saved := a.cursor
+ a.cursor.parent = parent
+ a.cursor.name = name
+ a.cursor.iter = iter
+ a.cursor.node = n
+
+ if a.pre != nil && !a.pre(&a.cursor) {
+ a.cursor = saved
+ return
+ }
+
+ // walk children
+ // (the order of the cases matches the order of the corresponding node types in go/ast)
+ switch n := n.(type) {
+ case nil:
+ // nothing to do
+
+ // Comments and fields
+ case *ast.Comment:
+ // nothing to do
+
+ case *ast.CommentGroup:
+ if n != nil {
+ a.applyList(n, "List")
+ }
+
+ case *ast.Field:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.applyList(n, "Names")
+ a.apply(n, "Type", nil, n.Type)
+ a.apply(n, "Tag", nil, n.Tag)
+ a.apply(n, "Comment", nil, n.Comment)
+
+ case *ast.FieldList:
+ a.applyList(n, "List")
+
+ // Expressions
+ case *ast.BadExpr, *ast.Ident, *ast.BasicLit:
+ // nothing to do
+
+ case *ast.Ellipsis:
+ a.apply(n, "Elt", nil, n.Elt)
+
+ case *ast.FuncLit:
+ a.apply(n, "Type", nil, n.Type)
+ a.apply(n, "Body", nil, n.Body)
+
+ case *ast.CompositeLit:
+ a.apply(n, "Type", nil, n.Type)
+ a.applyList(n, "Elts")
+
+ case *ast.ParenExpr:
+ a.apply(n, "X", nil, n.X)
+
+ case *ast.SelectorExpr:
+ a.apply(n, "X", nil, n.X)
+ a.apply(n, "Sel", nil, n.Sel)
+
+ case *ast.IndexExpr:
+ a.apply(n, "X", nil, n.X)
+ a.apply(n, "Index", nil, n.Index)
+
+ case *ast.SliceExpr:
+ a.apply(n, "X", nil, n.X)
+ a.apply(n, "Low", nil, n.Low)
+ a.apply(n, "High", nil, n.High)
+ a.apply(n, "Max", nil, n.Max)
+
+ case *ast.TypeAssertExpr:
+ a.apply(n, "X", nil, n.X)
+ a.apply(n, "Type", nil, n.Type)
+
+ case *ast.CallExpr:
+ a.apply(n, "Fun", nil, n.Fun)
+ a.applyList(n, "Args")
+
+ case *ast.StarExpr:
+ a.apply(n, "X", nil, n.X)
+
+ case *ast.UnaryExpr:
+ a.apply(n, "X", nil, n.X)
+
+ case *ast.BinaryExpr:
+ a.apply(n, "X", nil, n.X)
+ a.apply(n, "Y", nil, n.Y)
+
+ case *ast.KeyValueExpr:
+ a.apply(n, "Key", nil, n.Key)
+ a.apply(n, "Value", nil, n.Value)
+
+ // Types
+ case *ast.ArrayType:
+ a.apply(n, "Len", nil, n.Len)
+ a.apply(n, "Elt", nil, n.Elt)
+
+ case *ast.StructType:
+ a.apply(n, "Fields", nil, n.Fields)
+
+ case *ast.FuncType:
+ a.apply(n, "Params", nil, n.Params)
+ a.apply(n, "Results", nil, n.Results)
+
+ case *ast.InterfaceType:
+ a.apply(n, "Methods", nil, n.Methods)
+
+ case *ast.MapType:
+ a.apply(n, "Key", nil, n.Key)
+ a.apply(n, "Value", nil, n.Value)
+
+ case *ast.ChanType:
+ a.apply(n, "Value", nil, n.Value)
+
+ // Statements
+ case *ast.BadStmt:
+ // nothing to do
+
+ case *ast.DeclStmt:
+ a.apply(n, "Decl", nil, n.Decl)
+
+ case *ast.EmptyStmt:
+ // nothing to do
+
+ case *ast.LabeledStmt:
+ a.apply(n, "Label", nil, n.Label)
+ a.apply(n, "Stmt", nil, n.Stmt)
+
+ case *ast.ExprStmt:
+ a.apply(n, "X", nil, n.X)
+
+ case *ast.SendStmt:
+ a.apply(n, "Chan", nil, n.Chan)
+ a.apply(n, "Value", nil, n.Value)
+
+ case *ast.IncDecStmt:
+ a.apply(n, "X", nil, n.X)
+
+ case *ast.AssignStmt:
+ a.applyList(n, "Lhs")
+ a.applyList(n, "Rhs")
+
+ case *ast.GoStmt:
+ a.apply(n, "Call", nil, n.Call)
+
+ case *ast.DeferStmt:
+ a.apply(n, "Call", nil, n.Call)
+
+ case *ast.ReturnStmt:
+ a.applyList(n, "Results")
+
+ case *ast.BranchStmt:
+ a.apply(n, "Label", nil, n.Label)
+
+ case *ast.BlockStmt:
+ a.applyList(n, "List")
+
+ case *ast.IfStmt:
+ a.apply(n, "Init", nil, n.Init)
+ a.apply(n, "Cond", nil, n.Cond)
+ a.apply(n, "Body", nil, n.Body)
+ a.apply(n, "Else", nil, n.Else)
+
+ case *ast.CaseClause:
+ a.applyList(n, "List")
+ a.applyList(n, "Body")
+
+ case *ast.SwitchStmt:
+ a.apply(n, "Init", nil, n.Init)
+ a.apply(n, "Tag", nil, n.Tag)
+ a.apply(n, "Body", nil, n.Body)
+
+ case *ast.TypeSwitchStmt:
+ a.apply(n, "Init", nil, n.Init)
+ a.apply(n, "Assign", nil, n.Assign)
+ a.apply(n, "Body", nil, n.Body)
+
+ case *ast.CommClause:
+ a.apply(n, "Comm", nil, n.Comm)
+ a.applyList(n, "Body")
+
+ case *ast.SelectStmt:
+ a.apply(n, "Body", nil, n.Body)
+
+ case *ast.ForStmt:
+ a.apply(n, "Init", nil, n.Init)
+ a.apply(n, "Cond", nil, n.Cond)
+ a.apply(n, "Post", nil, n.Post)
+ a.apply(n, "Body", nil, n.Body)
+
+ case *ast.RangeStmt:
+ a.apply(n, "Key", nil, n.Key)
+ a.apply(n, "Value", nil, n.Value)
+ a.apply(n, "X", nil, n.X)
+ a.apply(n, "Body", nil, n.Body)
+
+ // Declarations
+ case *ast.ImportSpec:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.apply(n, "Name", nil, n.Name)
+ a.apply(n, "Path", nil, n.Path)
+ a.apply(n, "Comment", nil, n.Comment)
+
+ case *ast.ValueSpec:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.applyList(n, "Names")
+ a.apply(n, "Type", nil, n.Type)
+ a.applyList(n, "Values")
+ a.apply(n, "Comment", nil, n.Comment)
+
+ case *ast.TypeSpec:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.apply(n, "Name", nil, n.Name)
+ a.apply(n, "Type", nil, n.Type)
+ a.apply(n, "Comment", nil, n.Comment)
+
+ case *ast.BadDecl:
+ // nothing to do
+
+ case *ast.GenDecl:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.applyList(n, "Specs")
+
+ case *ast.FuncDecl:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.apply(n, "Recv", nil, n.Recv)
+ a.apply(n, "Name", nil, n.Name)
+ a.apply(n, "Type", nil, n.Type)
+ a.apply(n, "Body", nil, n.Body)
+
+ // Files and packages
+ case *ast.File:
+ a.apply(n, "Doc", nil, n.Doc)
+ a.apply(n, "Name", nil, n.Name)
+ a.applyList(n, "Decls")
+ // Don't walk n.Comments; they have either been walked already if
+ // they are Doc comments, or they can be easily walked explicitly.
+
+ case *ast.Package:
+ // collect and sort names for reproducible behavior
+ var names []string
+ for name := range n.Files {
+ names = append(names, name)
+ }
+ sort.Strings(names)
+ for _, name := range names {
+ a.apply(n, name, nil, n.Files[name])
+ }
+
+ default:
+ panic(fmt.Sprintf("Apply: unexpected node type %T", n))
+ }
+
+ if a.post != nil && !a.post(&a.cursor) {
+ panic(abort)
+ }
+
+ a.cursor = saved
+}
+
+// An iterator controls iteration over a slice of nodes.
+type iterator struct {
+ index, step int
+}
+
+func (a *application) applyList(parent ast.Node, name string) {
+ // avoid heap-allocating a new iterator for each applyList call; reuse a.iter instead
+ saved := a.iter
+ a.iter.index = 0
+ for {
+ // must reload parent.name each time, since cursor modifications might change it
+ v := reflect.Indirect(reflect.ValueOf(parent)).FieldByName(name)
+ if a.iter.index >= v.Len() {
+ break
+ }
+
+ // element x may be nil in a bad AST - be cautious
+ var x ast.Node
+ if e := v.Index(a.iter.index); e.IsValid() {
+ x = e.Interface().(ast.Node)
+ }
+
+ a.iter.step = 1
+ a.apply(parent, name, &a.iter, x)
+ a.iter.index += a.iter.step
+ }
+ a.iter = saved
+}
diff --git a/vendor/golang.org/x/tools/go/ast/astutil/util.go b/vendor/golang.org/x/tools/go/ast/astutil/util.go
new file mode 100644
index 00000000..76306298
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/ast/astutil/util.go
@@ -0,0 +1,14 @@
+package astutil
+
+import "go/ast"
+
+// Unparen returns e with any enclosing parentheses stripped.
+func Unparen(e ast.Expr) ast.Expr {
+ for {
+ p, ok := e.(*ast.ParenExpr)
+ if !ok {
+ return e
+ }
+ e = p.X
+ }
+}
diff --git a/vendor/golang.org/x/tools/go/buildutil/allpackages.go b/vendor/golang.org/x/tools/go/buildutil/allpackages.go
new file mode 100644
index 00000000..c0cb03e7
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/allpackages.go
@@ -0,0 +1,198 @@
+// Copyright 2014 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 buildutil provides utilities related to the go/build
+// package in the standard library.
+//
+// All I/O is done via the build.Context file system interface, which must
+// be concurrency-safe.
+package buildutil // import "golang.org/x/tools/go/buildutil"
+
+import (
+ "go/build"
+ "os"
+ "path/filepath"
+ "sort"
+ "strings"
+ "sync"
+)
+
+// AllPackages returns the package path of each Go package in any source
+// directory of the specified build context (e.g. $GOROOT or an element
+// of $GOPATH). Errors are ignored. The results are sorted.
+// All package paths are canonical, and thus may contain "/vendor/".
+//
+// The result may include import paths for directories that contain no
+// *.go files, such as "archive" (in $GOROOT/src).
+//
+// All I/O is done via the build.Context file system interface,
+// which must be concurrency-safe.
+//
+func AllPackages(ctxt *build.Context) []string {
+ var list []string
+ ForEachPackage(ctxt, func(pkg string, _ error) {
+ list = append(list, pkg)
+ })
+ sort.Strings(list)
+ return list
+}
+
+// ForEachPackage calls the found function with the package path of
+// each Go package it finds in any source directory of the specified
+// build context (e.g. $GOROOT or an element of $GOPATH).
+// All package paths are canonical, and thus may contain "/vendor/".
+//
+// If the package directory exists but could not be read, the second
+// argument to the found function provides the error.
+//
+// All I/O is done via the build.Context file system interface,
+// which must be concurrency-safe.
+//
+func ForEachPackage(ctxt *build.Context, found func(importPath string, err error)) {
+ ch := make(chan item)
+
+ var wg sync.WaitGroup
+ for _, root := range ctxt.SrcDirs() {
+ root := root
+ wg.Add(1)
+ go func() {
+ allPackages(ctxt, root, ch)
+ wg.Done()
+ }()
+ }
+ go func() {
+ wg.Wait()
+ close(ch)
+ }()
+
+ // All calls to found occur in the caller's goroutine.
+ for i := range ch {
+ found(i.importPath, i.err)
+ }
+}
+
+type item struct {
+ importPath string
+ err error // (optional)
+}
+
+// We use a process-wide counting semaphore to limit
+// the number of parallel calls to ReadDir.
+var ioLimit = make(chan bool, 20)
+
+func allPackages(ctxt *build.Context, root string, ch chan<- item) {
+ root = filepath.Clean(root) + string(os.PathSeparator)
+
+ var wg sync.WaitGroup
+
+ var walkDir func(dir string)
+ walkDir = func(dir string) {
+ // Avoid .foo, _foo, and testdata directory trees.
+ base := filepath.Base(dir)
+ if base == "" || base[0] == '.' || base[0] == '_' || base == "testdata" {
+ return
+ }
+
+ pkg := filepath.ToSlash(strings.TrimPrefix(dir, root))
+
+ // Prune search if we encounter any of these import paths.
+ switch pkg {
+ case "builtin":
+ return
+ }
+
+ ioLimit <- true
+ files, err := ReadDir(ctxt, dir)
+ <-ioLimit
+ if pkg != "" || err != nil {
+ ch <- item{pkg, err}
+ }
+ for _, fi := range files {
+ fi := fi
+ if fi.IsDir() {
+ wg.Add(1)
+ go func() {
+ walkDir(filepath.Join(dir, fi.Name()))
+ wg.Done()
+ }()
+ }
+ }
+ }
+
+ walkDir(root)
+ wg.Wait()
+}
+
+// ExpandPatterns returns the set of packages matched by patterns,
+// which may have the following forms:
+//
+// golang.org/x/tools/cmd/guru # a single package
+// golang.org/x/tools/... # all packages beneath dir
+// ... # the entire workspace.
+//
+// Order is significant: a pattern preceded by '-' removes matching
+// packages from the set. For example, these patterns match all encoding
+// packages except encoding/xml:
+//
+// encoding/... -encoding/xml
+//
+// A trailing slash in a pattern is ignored. (Path components of Go
+// package names are separated by slash, not the platform's path separator.)
+//
+func ExpandPatterns(ctxt *build.Context, patterns []string) map[string]bool {
+ // TODO(adonovan): support other features of 'go list':
+ // - "std"/"cmd"/"all" meta-packages
+ // - "..." not at the end of a pattern
+ // - relative patterns using "./" or "../" prefix
+
+ pkgs := make(map[string]bool)
+ doPkg := func(pkg string, neg bool) {
+ if neg {
+ delete(pkgs, pkg)
+ } else {
+ pkgs[pkg] = true
+ }
+ }
+
+ // Scan entire workspace if wildcards are present.
+ // TODO(adonovan): opt: scan only the necessary subtrees of the workspace.
+ var all []string
+ for _, arg := range patterns {
+ if strings.HasSuffix(arg, "...") {
+ all = AllPackages(ctxt)
+ break
+ }
+ }
+
+ for _, arg := range patterns {
+ if arg == "" {
+ continue
+ }
+
+ neg := arg[0] == '-'
+ if neg {
+ arg = arg[1:]
+ }
+
+ if arg == "..." {
+ // ... matches all packages
+ for _, pkg := range all {
+ doPkg(pkg, neg)
+ }
+ } else if dir := strings.TrimSuffix(arg, "/..."); dir != arg {
+ // dir/... matches all packages beneath dir
+ for _, pkg := range all {
+ if strings.HasPrefix(pkg, dir) &&
+ (len(pkg) == len(dir) || pkg[len(dir)] == '/') {
+ doPkg(pkg, neg)
+ }
+ }
+ } else {
+ // single package
+ doPkg(strings.TrimSuffix(arg, "/"), neg)
+ }
+ }
+
+ return pkgs
+}
diff --git a/vendor/golang.org/x/tools/go/buildutil/fakecontext.go b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go
new file mode 100644
index 00000000..8b7f0667
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go
@@ -0,0 +1,109 @@
+package buildutil
+
+import (
+ "fmt"
+ "go/build"
+ "io"
+ "io/ioutil"
+ "os"
+ "path"
+ "path/filepath"
+ "sort"
+ "strings"
+ "time"
+)
+
+// FakeContext returns a build.Context for the fake file tree specified
+// by pkgs, which maps package import paths to a mapping from file base
+// names to contents.
+//
+// The fake Context has a GOROOT of "/go" and no GOPATH, and overrides
+// the necessary file access methods to read from memory instead of the
+// real file system.
+//
+// Unlike a real file tree, the fake one has only two levels---packages
+// and files---so ReadDir("/go/src/") returns all packages under
+// /go/src/ including, for instance, "math" and "math/big".
+// ReadDir("/go/src/math/big") would return all the files in the
+// "math/big" package.
+//
+func FakeContext(pkgs map[string]map[string]string) *build.Context {
+ clean := func(filename string) string {
+ f := path.Clean(filepath.ToSlash(filename))
+ // Removing "/go/src" while respecting segment
+ // boundaries has this unfortunate corner case:
+ if f == "/go/src" {
+ return ""
+ }
+ return strings.TrimPrefix(f, "/go/src/")
+ }
+
+ ctxt := build.Default // copy
+ ctxt.GOROOT = "/go"
+ ctxt.GOPATH = ""
+ ctxt.Compiler = "gc"
+ ctxt.IsDir = func(dir string) bool {
+ dir = clean(dir)
+ if dir == "" {
+ return true // needed by (*build.Context).SrcDirs
+ }
+ return pkgs[dir] != nil
+ }
+ ctxt.ReadDir = func(dir string) ([]os.FileInfo, error) {
+ dir = clean(dir)
+ var fis []os.FileInfo
+ if dir == "" {
+ // enumerate packages
+ for importPath := range pkgs {
+ fis = append(fis, fakeDirInfo(importPath))
+ }
+ } else {
+ // enumerate files of package
+ for basename := range pkgs[dir] {
+ fis = append(fis, fakeFileInfo(basename))
+ }
+ }
+ sort.Sort(byName(fis))
+ return fis, nil
+ }
+ ctxt.OpenFile = func(filename string) (io.ReadCloser, error) {
+ filename = clean(filename)
+ dir, base := path.Split(filename)
+ content, ok := pkgs[path.Clean(dir)][base]
+ if !ok {
+ return nil, fmt.Errorf("file not found: %s", filename)
+ }
+ return ioutil.NopCloser(strings.NewReader(content)), nil
+ }
+ ctxt.IsAbsPath = func(path string) bool {
+ path = filepath.ToSlash(path)
+ // Don't rely on the default (filepath.Path) since on
+ // Windows, it reports virtual paths as non-absolute.
+ return strings.HasPrefix(path, "/")
+ }
+ return &ctxt
+}
+
+type byName []os.FileInfo
+
+func (s byName) Len() int { return len(s) }
+func (s byName) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+func (s byName) Less(i, j int) bool { return s[i].Name() < s[j].Name() }
+
+type fakeFileInfo string
+
+func (fi fakeFileInfo) Name() string { return string(fi) }
+func (fakeFileInfo) Sys() interface{} { return nil }
+func (fakeFileInfo) ModTime() time.Time { return time.Time{} }
+func (fakeFileInfo) IsDir() bool { return false }
+func (fakeFileInfo) Size() int64 { return 0 }
+func (fakeFileInfo) Mode() os.FileMode { return 0644 }
+
+type fakeDirInfo string
+
+func (fd fakeDirInfo) Name() string { return string(fd) }
+func (fakeDirInfo) Sys() interface{} { return nil }
+func (fakeDirInfo) ModTime() time.Time { return time.Time{} }
+func (fakeDirInfo) IsDir() bool { return true }
+func (fakeDirInfo) Size() int64 { return 0 }
+func (fakeDirInfo) Mode() os.FileMode { return 0755 }
diff --git a/vendor/golang.org/x/tools/go/buildutil/overlay.go b/vendor/golang.org/x/tools/go/buildutil/overlay.go
new file mode 100644
index 00000000..3f71c4fe
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/overlay.go
@@ -0,0 +1,103 @@
+// Copyright 2016 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 buildutil
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "go/build"
+ "io"
+ "io/ioutil"
+ "path/filepath"
+ "strconv"
+ "strings"
+)
+
+// OverlayContext overlays a build.Context with additional files from
+// a map. Files in the map take precedence over other files.
+//
+// In addition to plain string comparison, two file names are
+// considered equal if their base names match and their directory
+// components point at the same directory on the file system. That is,
+// symbolic links are followed for directories, but not files.
+//
+// A common use case for OverlayContext is to allow editors to pass in
+// a set of unsaved, modified files.
+//
+// Currently, only the Context.OpenFile function will respect the
+// overlay. This may change in the future.
+func OverlayContext(orig *build.Context, overlay map[string][]byte) *build.Context {
+ // TODO(dominikh): Implement IsDir, HasSubdir and ReadDir
+
+ rc := func(data []byte) (io.ReadCloser, error) {
+ return ioutil.NopCloser(bytes.NewBuffer(data)), nil
+ }
+
+ copy := *orig // make a copy
+ ctxt := &copy
+ ctxt.OpenFile = func(path string) (io.ReadCloser, error) {
+ // Fast path: names match exactly.
+ if content, ok := overlay[path]; ok {
+ return rc(content)
+ }
+
+ // Slow path: check for same file under a different
+ // alias, perhaps due to a symbolic link.
+ for filename, content := range overlay {
+ if sameFile(path, filename) {
+ return rc(content)
+ }
+ }
+
+ return OpenFile(orig, path)
+ }
+ return ctxt
+}
+
+// ParseOverlayArchive parses an archive containing Go files and their
+// contents. The result is intended to be used with OverlayContext.
+//
+//
+// Archive format
+//
+// The archive consists of a series of files. Each file consists of a
+// name, a decimal file size and the file contents, separated by
+// newlinews. No newline follows after the file contents.
+func ParseOverlayArchive(archive io.Reader) (map[string][]byte, error) {
+ overlay := make(map[string][]byte)
+ r := bufio.NewReader(archive)
+ for {
+ // Read file name.
+ filename, err := r.ReadString('\n')
+ if err != nil {
+ if err == io.EOF {
+ break // OK
+ }
+ return nil, fmt.Errorf("reading archive file name: %v", err)
+ }
+ filename = filepath.Clean(strings.TrimSpace(filename))
+
+ // Read file size.
+ sz, err := r.ReadString('\n')
+ if err != nil {
+ return nil, fmt.Errorf("reading size of archive file %s: %v", filename, err)
+ }
+ sz = strings.TrimSpace(sz)
+ size, err := strconv.ParseUint(sz, 10, 32)
+ if err != nil {
+ return nil, fmt.Errorf("parsing size of archive file %s: %v", filename, err)
+ }
+
+ // Read file content.
+ content := make([]byte, size)
+ if _, err := io.ReadFull(r, content); err != nil {
+ return nil, fmt.Errorf("reading archive file %s: %v", filename, err)
+ }
+ overlay[filename] = content
+ }
+
+ return overlay, nil
+}
diff --git a/vendor/golang.org/x/tools/go/buildutil/tags.go b/vendor/golang.org/x/tools/go/buildutil/tags.go
new file mode 100644
index 00000000..486606f3
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/tags.go
@@ -0,0 +1,75 @@
+package buildutil
+
+// This logic was copied from stringsFlag from $GOROOT/src/cmd/go/build.go.
+
+import "fmt"
+
+const TagsFlagDoc = "a list of `build tags` to consider satisfied during the build. " +
+ "For more information about build tags, see the description of " +
+ "build constraints in the documentation for the go/build package"
+
+// TagsFlag is an implementation of the flag.Value and flag.Getter interfaces that parses
+// a flag value in the same manner as go build's -tags flag and
+// populates a []string slice.
+//
+// See $GOROOT/src/go/build/doc.go for description of build tags.
+// See $GOROOT/src/cmd/go/doc.go for description of 'go build -tags' flag.
+//
+// Example:
+// flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
+type TagsFlag []string
+
+func (v *TagsFlag) Set(s string) error {
+ var err error
+ *v, err = splitQuotedFields(s)
+ if *v == nil {
+ *v = []string{}
+ }
+ return err
+}
+
+func (v *TagsFlag) Get() interface{} { return *v }
+
+func splitQuotedFields(s string) ([]string, error) {
+ // Split fields allowing '' or "" around elements.
+ // Quotes further inside the string do not count.
+ var f []string
+ for len(s) > 0 {
+ for len(s) > 0 && isSpaceByte(s[0]) {
+ s = s[1:]
+ }
+ if len(s) == 0 {
+ break
+ }
+ // Accepted quoted string. No unescaping inside.
+ if s[0] == '"' || s[0] == '\'' {
+ quote := s[0]
+ s = s[1:]
+ i := 0
+ for i < len(s) && s[i] != quote {
+ i++
+ }
+ if i >= len(s) {
+ return nil, fmt.Errorf("unterminated %c string", quote)
+ }
+ f = append(f, s[:i])
+ s = s[i+1:]
+ continue
+ }
+ i := 0
+ for i < len(s) && !isSpaceByte(s[i]) {
+ i++
+ }
+ f = append(f, s[:i])
+ s = s[i:]
+ }
+ return f, nil
+}
+
+func (v *TagsFlag) String() string {
+ return "<tagsFlag>"
+}
+
+func isSpaceByte(c byte) bool {
+ return c == ' ' || c == '\t' || c == '\n' || c == '\r'
+}
diff --git a/vendor/golang.org/x/tools/go/buildutil/util.go b/vendor/golang.org/x/tools/go/buildutil/util.go
new file mode 100644
index 00000000..fc923d7a
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/util.go
@@ -0,0 +1,212 @@
+// Copyright 2014 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 buildutil
+
+import (
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "io"
+ "io/ioutil"
+ "os"
+ "path"
+ "path/filepath"
+ "strings"
+)
+
+// ParseFile behaves like parser.ParseFile,
+// but uses the build context's file system interface, if any.
+//
+// If file is not absolute (as defined by IsAbsPath), the (dir, file)
+// components are joined using JoinPath; dir must be absolute.
+//
+// The displayPath function, if provided, is used to transform the
+// filename that will be attached to the ASTs.
+//
+// TODO(adonovan): call this from go/loader.parseFiles when the tree thaws.
+//
+func ParseFile(fset *token.FileSet, ctxt *build.Context, displayPath func(string) string, dir string, file string, mode parser.Mode) (*ast.File, error) {
+ if !IsAbsPath(ctxt, file) {
+ file = JoinPath(ctxt, dir, file)
+ }
+ rd, err := OpenFile(ctxt, file)
+ if err != nil {
+ return nil, err
+ }
+ defer rd.Close() // ignore error
+ if displayPath != nil {
+ file = displayPath(file)
+ }
+ return parser.ParseFile(fset, file, rd, mode)
+}
+
+// ContainingPackage returns the package containing filename.
+//
+// If filename is not absolute, it is interpreted relative to working directory dir.
+// All I/O is via the build context's file system interface, if any.
+//
+// The '...Files []string' fields of the resulting build.Package are not
+// populated (build.FindOnly mode).
+//
+func ContainingPackage(ctxt *build.Context, dir, filename string) (*build.Package, error) {
+ if !IsAbsPath(ctxt, filename) {
+ filename = JoinPath(ctxt, dir, filename)
+ }
+
+ // We must not assume the file tree uses
+ // "/" always,
+ // `\` always,
+ // or os.PathSeparator (which varies by platform),
+ // but to make any progress, we are forced to assume that
+ // paths will not use `\` unless the PathSeparator
+ // is also `\`, thus we can rely on filepath.ToSlash for some sanity.
+
+ dirSlash := path.Dir(filepath.ToSlash(filename)) + "/"
+
+ // We assume that no source root (GOPATH[i] or GOROOT) contains any other.
+ for _, srcdir := range ctxt.SrcDirs() {
+ srcdirSlash := filepath.ToSlash(srcdir) + "/"
+ if importPath, ok := HasSubdir(ctxt, srcdirSlash, dirSlash); ok {
+ return ctxt.Import(importPath, dir, build.FindOnly)
+ }
+ }
+
+ return nil, fmt.Errorf("can't find package containing %s", filename)
+}
+
+// -- Effective methods of file system interface -------------------------
+
+// (go/build.Context defines these as methods, but does not export them.)
+
+// hasSubdir calls ctxt.HasSubdir (if not nil) or else uses
+// the local file system to answer the question.
+func HasSubdir(ctxt *build.Context, root, dir string) (rel string, ok bool) {
+ if f := ctxt.HasSubdir; f != nil {
+ return f(root, dir)
+ }
+
+ // Try using paths we received.
+ if rel, ok = hasSubdir(root, dir); ok {
+ return
+ }
+
+ // Try expanding symlinks and comparing
+ // expanded against unexpanded and
+ // expanded against expanded.
+ rootSym, _ := filepath.EvalSymlinks(root)
+ dirSym, _ := filepath.EvalSymlinks(dir)
+
+ if rel, ok = hasSubdir(rootSym, dir); ok {
+ return
+ }
+ if rel, ok = hasSubdir(root, dirSym); ok {
+ return
+ }
+ return hasSubdir(rootSym, dirSym)
+}
+
+func hasSubdir(root, dir string) (rel string, ok bool) {
+ const sep = string(filepath.Separator)
+ root = filepath.Clean(root)
+ if !strings.HasSuffix(root, sep) {
+ root += sep
+ }
+
+ dir = filepath.Clean(dir)
+ if !strings.HasPrefix(dir, root) {
+ return "", false
+ }
+
+ return filepath.ToSlash(dir[len(root):]), true
+}
+
+// FileExists returns true if the specified file exists,
+// using the build context's file system interface.
+func FileExists(ctxt *build.Context, path string) bool {
+ if ctxt.OpenFile != nil {
+ r, err := ctxt.OpenFile(path)
+ if err != nil {
+ return false
+ }
+ r.Close() // ignore error
+ return true
+ }
+ _, err := os.Stat(path)
+ return err == nil
+}
+
+// OpenFile behaves like os.Open,
+// but uses the build context's file system interface, if any.
+func OpenFile(ctxt *build.Context, path string) (io.ReadCloser, error) {
+ if ctxt.OpenFile != nil {
+ return ctxt.OpenFile(path)
+ }
+ return os.Open(path)
+}
+
+// IsAbsPath behaves like filepath.IsAbs,
+// but uses the build context's file system interface, if any.
+func IsAbsPath(ctxt *build.Context, path string) bool {
+ if ctxt.IsAbsPath != nil {
+ return ctxt.IsAbsPath(path)
+ }
+ return filepath.IsAbs(path)
+}
+
+// JoinPath behaves like filepath.Join,
+// but uses the build context's file system interface, if any.
+func JoinPath(ctxt *build.Context, path ...string) string {
+ if ctxt.JoinPath != nil {
+ return ctxt.JoinPath(path...)
+ }
+ return filepath.Join(path...)
+}
+
+// IsDir behaves like os.Stat plus IsDir,
+// but uses the build context's file system interface, if any.
+func IsDir(ctxt *build.Context, path string) bool {
+ if ctxt.IsDir != nil {
+ return ctxt.IsDir(path)
+ }
+ fi, err := os.Stat(path)
+ return err == nil && fi.IsDir()
+}
+
+// ReadDir behaves like ioutil.ReadDir,
+// but uses the build context's file system interface, if any.
+func ReadDir(ctxt *build.Context, path string) ([]os.FileInfo, error) {
+ if ctxt.ReadDir != nil {
+ return ctxt.ReadDir(path)
+ }
+ return ioutil.ReadDir(path)
+}
+
+// SplitPathList behaves like filepath.SplitList,
+// but uses the build context's file system interface, if any.
+func SplitPathList(ctxt *build.Context, s string) []string {
+ if ctxt.SplitPathList != nil {
+ return ctxt.SplitPathList(s)
+ }
+ return filepath.SplitList(s)
+}
+
+// sameFile returns true if x and y have the same basename and denote
+// the same file.
+//
+func sameFile(x, y string) bool {
+ if path.Clean(x) == path.Clean(y) {
+ return true
+ }
+ if filepath.Base(x) == filepath.Base(y) { // (optimisation)
+ if xi, err := os.Stat(x); err == nil {
+ if yi, err := os.Stat(y); err == nil {
+ return os.SameFile(xi, yi)
+ }
+ }
+ }
+ return false
+}
diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go
new file mode 100644
index 00000000..0f652ea6
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go
@@ -0,0 +1,220 @@
+// 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 cgo
+
+// This file handles cgo preprocessing of files containing `import "C"`.
+//
+// DESIGN
+//
+// The approach taken is to run the cgo processor on the package's
+// CgoFiles and parse the output, faking the filenames of the
+// resulting ASTs so that the synthetic file containing the C types is
+// called "C" (e.g. "~/go/src/net/C") and the preprocessed files
+// have their original names (e.g. "~/go/src/net/cgo_unix.go"),
+// not the names of the actual temporary files.
+//
+// The advantage of this approach is its fidelity to 'go build'. The
+// downside is that the token.Position.Offset for each AST node is
+// incorrect, being an offset within the temporary file. Line numbers
+// should still be correct because of the //line comments.
+//
+// The logic of this file is mostly plundered from the 'go build'
+// tool, which also invokes the cgo preprocessor.
+//
+//
+// REJECTED ALTERNATIVE
+//
+// An alternative approach that we explored is to extend go/types'
+// Importer mechanism to provide the identity of the importing package
+// so that each time `import "C"` appears it resolves to a different
+// synthetic package containing just the objects needed in that case.
+// The loader would invoke cgo but parse only the cgo_types.go file
+// defining the package-level objects, discarding the other files
+// resulting from preprocessing.
+//
+// The benefit of this approach would have been that source-level
+// syntax information would correspond exactly to the original cgo
+// file, with no preprocessing involved, making source tools like
+// godoc, guru, and eg happy. However, the approach was rejected
+// due to the additional complexity it would impose on go/types. (It
+// made for a beautiful demo, though.)
+//
+// cgo files, despite their *.go extension, are not legal Go source
+// files per the specification since they may refer to unexported
+// members of package "C" such as C.int. Also, a function such as
+// C.getpwent has in effect two types, one matching its C type and one
+// which additionally returns (errno C.int). The cgo preprocessor
+// uses name mangling to distinguish these two functions in the
+// processed code, but go/types would need to duplicate this logic in
+// its handling of function calls, analogous to the treatment of map
+// lookups in which y=m[k] and y,ok=m[k] are both legal.
+
+import (
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "io/ioutil"
+ "log"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "regexp"
+ "strings"
+)
+
+// ProcessFiles invokes the cgo preprocessor on bp.CgoFiles, parses
+// the output and returns the resulting ASTs.
+//
+func ProcessFiles(bp *build.Package, fset *token.FileSet, DisplayPath func(path string) string, mode parser.Mode) ([]*ast.File, error) {
+ tmpdir, err := ioutil.TempDir("", strings.Replace(bp.ImportPath, "/", "_", -1)+"_C")
+ if err != nil {
+ return nil, err
+ }
+ defer os.RemoveAll(tmpdir)
+
+ pkgdir := bp.Dir
+ if DisplayPath != nil {
+ pkgdir = DisplayPath(pkgdir)
+ }
+
+ cgoFiles, cgoDisplayFiles, err := Run(bp, pkgdir, tmpdir, false)
+ if err != nil {
+ return nil, err
+ }
+ var files []*ast.File
+ for i := range cgoFiles {
+ rd, err := os.Open(cgoFiles[i])
+ if err != nil {
+ return nil, err
+ }
+ display := filepath.Join(bp.Dir, cgoDisplayFiles[i])
+ f, err := parser.ParseFile(fset, display, rd, mode)
+ rd.Close()
+ if err != nil {
+ return nil, err
+ }
+ files = append(files, f)
+ }
+ return files, nil
+}
+
+var cgoRe = regexp.MustCompile(`[/\\:]`)
+
+// Run invokes the cgo preprocessor on bp.CgoFiles and returns two
+// lists of files: the resulting processed files (in temporary
+// directory tmpdir) and the corresponding names of the unprocessed files.
+//
+// Run is adapted from (*builder).cgo in
+// $GOROOT/src/cmd/go/build.go, but these features are unsupported:
+// Objective C, CGOPKGPATH, CGO_FLAGS.
+//
+// If useabs is set to true, absolute paths of the bp.CgoFiles will be passed in
+// to the cgo preprocessor. This in turn will set the // line comments
+// referring to those files to use absolute paths. This is needed for
+// go/packages using the legacy go list support so it is able to find
+// the original files.
+func Run(bp *build.Package, pkgdir, tmpdir string, useabs bool) (files, displayFiles []string, err error) {
+ cgoCPPFLAGS, _, _, _ := cflags(bp, true)
+ _, cgoexeCFLAGS, _, _ := cflags(bp, false)
+
+ if len(bp.CgoPkgConfig) > 0 {
+ pcCFLAGS, err := pkgConfigFlags(bp)
+ if err != nil {
+ return nil, nil, err
+ }
+ cgoCPPFLAGS = append(cgoCPPFLAGS, pcCFLAGS...)
+ }
+
+ // Allows including _cgo_export.h from .[ch] files in the package.
+ cgoCPPFLAGS = append(cgoCPPFLAGS, "-I", tmpdir)
+
+ // _cgo_gotypes.go (displayed "C") contains the type definitions.
+ files = append(files, filepath.Join(tmpdir, "_cgo_gotypes.go"))
+ displayFiles = append(displayFiles, "C")
+ for _, fn := range bp.CgoFiles {
+ // "foo.cgo1.go" (displayed "foo.go") is the processed Go source.
+ f := cgoRe.ReplaceAllString(fn[:len(fn)-len("go")], "_")
+ files = append(files, filepath.Join(tmpdir, f+"cgo1.go"))
+ displayFiles = append(displayFiles, fn)
+ }
+
+ var cgoflags []string
+ if bp.Goroot && bp.ImportPath == "runtime/cgo" {
+ cgoflags = append(cgoflags, "-import_runtime_cgo=false")
+ }
+ if bp.Goroot && bp.ImportPath == "runtime/race" || bp.ImportPath == "runtime/cgo" {
+ cgoflags = append(cgoflags, "-import_syscall=false")
+ }
+
+ var cgoFiles []string = bp.CgoFiles
+ if useabs {
+ cgoFiles = make([]string, len(bp.CgoFiles))
+ for i := range cgoFiles {
+ cgoFiles[i] = filepath.Join(pkgdir, bp.CgoFiles[i])
+ }
+ }
+
+ args := stringList(
+ "go", "tool", "cgo", "-objdir", tmpdir, cgoflags, "--",
+ cgoCPPFLAGS, cgoexeCFLAGS, cgoFiles,
+ )
+ if false {
+ log.Printf("Running cgo for package %q: %s (dir=%s)", bp.ImportPath, args, pkgdir)
+ }
+ cmd := exec.Command(args[0], args[1:]...)
+ cmd.Dir = pkgdir
+ cmd.Stdout = os.Stderr
+ cmd.Stderr = os.Stderr
+ if err := cmd.Run(); err != nil {
+ return nil, nil, fmt.Errorf("cgo failed: %s: %s", args, err)
+ }
+
+ return files, displayFiles, nil
+}
+
+// -- unmodified from 'go build' ---------------------------------------
+
+// Return the flags to use when invoking the C or C++ compilers, or cgo.
+func cflags(p *build.Package, def bool) (cppflags, cflags, cxxflags, ldflags []string) {
+ var defaults string
+ if def {
+ defaults = "-g -O2"
+ }
+
+ cppflags = stringList(envList("CGO_CPPFLAGS", ""), p.CgoCPPFLAGS)
+ cflags = stringList(envList("CGO_CFLAGS", defaults), p.CgoCFLAGS)
+ cxxflags = stringList(envList("CGO_CXXFLAGS", defaults), p.CgoCXXFLAGS)
+ ldflags = stringList(envList("CGO_LDFLAGS", defaults), p.CgoLDFLAGS)
+ return
+}
+
+// envList returns the value of the given environment variable broken
+// into fields, using the default value when the variable is empty.
+func envList(key, def string) []string {
+ v := os.Getenv(key)
+ if v == "" {
+ v = def
+ }
+ return strings.Fields(v)
+}
+
+// stringList's arguments should be a sequence of string or []string values.
+// stringList flattens them into a single []string.
+func stringList(args ...interface{}) []string {
+ var x []string
+ for _, arg := range args {
+ switch arg := arg.(type) {
+ case []string:
+ x = append(x, arg...)
+ case string:
+ x = append(x, arg)
+ default:
+ panic("stringList: invalid argument")
+ }
+ }
+ return x
+}
diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go
new file mode 100644
index 00000000..b5bb95a6
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go
@@ -0,0 +1,39 @@
+// 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 cgo
+
+import (
+ "errors"
+ "fmt"
+ "go/build"
+ "os/exec"
+ "strings"
+)
+
+// pkgConfig runs pkg-config with the specified arguments and returns the flags it prints.
+func pkgConfig(mode string, pkgs []string) (flags []string, err error) {
+ cmd := exec.Command("pkg-config", append([]string{mode}, pkgs...)...)
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ s := fmt.Sprintf("%s failed: %v", strings.Join(cmd.Args, " "), err)
+ if len(out) > 0 {
+ s = fmt.Sprintf("%s: %s", s, out)
+ }
+ return nil, errors.New(s)
+ }
+ if len(out) > 0 {
+ flags = strings.Fields(string(out))
+ }
+ return
+}
+
+// pkgConfigFlags calls pkg-config if needed and returns the cflags
+// needed to build the package.
+func pkgConfigFlags(p *build.Package) (cflags []string, err error) {
+ if len(p.CgoPkgConfig) == 0 {
+ return nil, nil
+ }
+ return pkgConfig("--cflags", p.CgoPkgConfig)
+}
diff --git a/vendor/golang.org/x/tools/go/loader/doc.go b/vendor/golang.org/x/tools/go/loader/doc.go
new file mode 100644
index 00000000..9b51c9ec
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/loader/doc.go
@@ -0,0 +1,205 @@
+// Copyright 2015 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 loader loads a complete Go program from source code, parsing
+// and type-checking the initial packages plus their transitive closure
+// of dependencies. The ASTs and the derived facts are retained for
+// later use.
+//
+// THIS INTERFACE IS EXPERIMENTAL AND IS LIKELY TO CHANGE.
+//
+// The package defines two primary types: Config, which specifies a
+// set of initial packages to load and various other options; and
+// Program, which is the result of successfully loading the packages
+// specified by a configuration.
+//
+// The configuration can be set directly, but *Config provides various
+// convenience methods to simplify the common cases, each of which can
+// be called any number of times. Finally, these are followed by a
+// call to Load() to actually load and type-check the program.
+//
+// var conf loader.Config
+//
+// // Use the command-line arguments to specify
+// // a set of initial packages to load from source.
+// // See FromArgsUsage for help.
+// rest, err := conf.FromArgs(os.Args[1:], wantTests)
+//
+// // Parse the specified files and create an ad hoc package with path "foo".
+// // All files must have the same 'package' declaration.
+// conf.CreateFromFilenames("foo", "foo.go", "bar.go")
+//
+// // Create an ad hoc package with path "foo" from
+// // the specified already-parsed files.
+// // All ASTs must have the same 'package' declaration.
+// conf.CreateFromFiles("foo", parsedFiles)
+//
+// // Add "runtime" to the set of packages to be loaded.
+// conf.Import("runtime")
+//
+// // Adds "fmt" and "fmt_test" to the set of packages
+// // to be loaded. "fmt" will include *_test.go files.
+// conf.ImportWithTests("fmt")
+//
+// // Finally, load all the packages specified by the configuration.
+// prog, err := conf.Load()
+//
+// See examples_test.go for examples of API usage.
+//
+//
+// CONCEPTS AND TERMINOLOGY
+//
+// The WORKSPACE is the set of packages accessible to the loader. The
+// workspace is defined by Config.Build, a *build.Context. The
+// default context treats subdirectories of $GOROOT and $GOPATH as
+// packages, but this behavior may be overridden.
+//
+// An AD HOC package is one specified as a set of source files on the
+// command line. In the simplest case, it may consist of a single file
+// such as $GOROOT/src/net/http/triv.go.
+//
+// EXTERNAL TEST packages are those comprised of a set of *_test.go
+// files all with the same 'package foo_test' declaration, all in the
+// same directory. (go/build.Package calls these files XTestFiles.)
+//
+// An IMPORTABLE package is one that can be referred to by some import
+// spec. Every importable package is uniquely identified by its
+// PACKAGE PATH or just PATH, a string such as "fmt", "encoding/json",
+// or "cmd/vendor/golang.org/x/arch/x86/x86asm". A package path
+// typically denotes a subdirectory of the workspace.
+//
+// An import declaration uses an IMPORT PATH to refer to a package.
+// Most import declarations use the package path as the import path.
+//
+// Due to VENDORING (https://golang.org/s/go15vendor), the
+// interpretation of an import path may depend on the directory in which
+// it appears. To resolve an import path to a package path, go/build
+// must search the enclosing directories for a subdirectory named
+// "vendor".
+//
+// ad hoc packages and external test packages are NON-IMPORTABLE. The
+// path of an ad hoc package is inferred from the package
+// declarations of its files and is therefore not a unique package key.
+// For example, Config.CreatePkgs may specify two initial ad hoc
+// packages, both with path "main".
+//
+// An AUGMENTED package is an importable package P plus all the
+// *_test.go files with same 'package foo' declaration as P.
+// (go/build.Package calls these files TestFiles.)
+//
+// The INITIAL packages are those specified in the configuration. A
+// DEPENDENCY is a package loaded to satisfy an import in an initial
+// package or another dependency.
+//
+package loader
+
+// IMPLEMENTATION NOTES
+//
+// 'go test', in-package test files, and import cycles
+// ---------------------------------------------------
+//
+// An external test package may depend upon members of the augmented
+// package that are not in the unaugmented package, such as functions
+// that expose internals. (See bufio/export_test.go for an example.)
+// So, the loader must ensure that for each external test package
+// it loads, it also augments the corresponding non-test package.
+//
+// The import graph over n unaugmented packages must be acyclic; the
+// import graph over n-1 unaugmented packages plus one augmented
+// package must also be acyclic. ('go test' relies on this.) But the
+// import graph over n augmented packages may contain cycles.
+//
+// First, all the (unaugmented) non-test packages and their
+// dependencies are imported in the usual way; the loader reports an
+// error if it detects an import cycle.
+//
+// Then, each package P for which testing is desired is augmented by
+// the list P' of its in-package test files, by calling
+// (*types.Checker).Files. This arrangement ensures that P' may
+// reference definitions within P, but P may not reference definitions
+// within P'. Furthermore, P' may import any other package, including
+// ones that depend upon P, without an import cycle error.
+//
+// Consider two packages A and B, both of which have lists of
+// in-package test files we'll call A' and B', and which have the
+// following import graph edges:
+// B imports A
+// B' imports A
+// A' imports B
+// This last edge would be expected to create an error were it not
+// for the special type-checking discipline above.
+// Cycles of size greater than two are possible. For example:
+// compress/bzip2/bzip2_test.go (package bzip2) imports "io/ioutil"
+// io/ioutil/tempfile_test.go (package ioutil) imports "regexp"
+// regexp/exec_test.go (package regexp) imports "compress/bzip2"
+//
+//
+// Concurrency
+// -----------
+//
+// Let us define the import dependency graph as follows. Each node is a
+// list of files passed to (Checker).Files at once. Many of these lists
+// are the production code of an importable Go package, so those nodes
+// are labelled by the package's path. The remaining nodes are
+// ad hoc packages and lists of in-package *_test.go files that augment
+// an importable package; those nodes have no label.
+//
+// The edges of the graph represent import statements appearing within a
+// file. An edge connects a node (a list of files) to the node it
+// imports, which is importable and thus always labelled.
+//
+// Loading is controlled by this dependency graph.
+//
+// To reduce I/O latency, we start loading a package's dependencies
+// asynchronously as soon as we've parsed its files and enumerated its
+// imports (scanImports). This performs a preorder traversal of the
+// import dependency graph.
+//
+// To exploit hardware parallelism, we type-check unrelated packages in
+// parallel, where "unrelated" means not ordered by the partial order of
+// the import dependency graph.
+//
+// We use a concurrency-safe non-blocking cache (importer.imported) to
+// record the results of type-checking, whether success or failure. An
+// entry is created in this cache by startLoad the first time the
+// package is imported. The first goroutine to request an entry becomes
+// responsible for completing the task and broadcasting completion to
+// subsequent requestors, which block until then.
+//
+// Type checking occurs in (parallel) postorder: we cannot type-check a
+// set of files until we have loaded and type-checked all of their
+// immediate dependencies (and thus all of their transitive
+// dependencies). If the input were guaranteed free of import cycles,
+// this would be trivial: we could simply wait for completion of the
+// dependencies and then invoke the typechecker.
+//
+// But as we saw in the 'go test' section above, some cycles in the
+// import graph over packages are actually legal, so long as the
+// cycle-forming edge originates in the in-package test files that
+// augment the package. This explains why the nodes of the import
+// dependency graph are not packages, but lists of files: the unlabelled
+// nodes avoid the cycles. Consider packages A and B where B imports A
+// and A's in-package tests AT import B. The naively constructed import
+// graph over packages would contain a cycle (A+AT) --> B --> (A+AT) but
+// the graph over lists of files is AT --> B --> A, where AT is an
+// unlabelled node.
+//
+// Awaiting completion of the dependencies in a cyclic graph would
+// deadlock, so we must materialize the import dependency graph (as
+// importer.graph) and check whether each import edge forms a cycle. If
+// x imports y, and the graph already contains a path from y to x, then
+// there is an import cycle, in which case the processing of x must not
+// wait for the completion of processing of y.
+//
+// When the type-checker makes a callback (doImport) to the loader for a
+// given import edge, there are two possible cases. In the normal case,
+// the dependency has already been completely type-checked; doImport
+// does a cache lookup and returns it. In the cyclic case, the entry in
+// the cache is still necessarily incomplete, indicating a cycle. We
+// perform the cycle check again to obtain the error message, and return
+// the error.
+//
+// The result of using concurrency is about a 2.5x speedup for stdlib_test.
+
+// TODO(adonovan): overhaul the package documentation.
diff --git a/vendor/golang.org/x/tools/go/loader/loader.go b/vendor/golang.org/x/tools/go/loader/loader.go
new file mode 100644
index 00000000..c4566611
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/loader/loader.go
@@ -0,0 +1,1078 @@
+// 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 loader
+
+// See doc.go for package documentation and implementation notes.
+
+import (
+ "errors"
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "go/types"
+ "os"
+ "path/filepath"
+ "sort"
+ "strings"
+ "sync"
+ "time"
+
+ "golang.org/x/tools/go/ast/astutil"
+ "golang.org/x/tools/go/internal/cgo"
+)
+
+var ignoreVendor build.ImportMode
+
+const trace = false // show timing info for type-checking
+
+// Config specifies the configuration for loading a whole program from
+// Go source code.
+// The zero value for Config is a ready-to-use default configuration.
+type Config struct {
+ // Fset is the file set for the parser to use when loading the
+ // program. If nil, it may be lazily initialized by any
+ // method of Config.
+ Fset *token.FileSet
+
+ // ParserMode specifies the mode to be used by the parser when
+ // loading source packages.
+ ParserMode parser.Mode
+
+ // TypeChecker contains options relating to the type checker.
+ //
+ // The supplied IgnoreFuncBodies is not used; the effective
+ // value comes from the TypeCheckFuncBodies func below.
+ // The supplied Import function is not used either.
+ TypeChecker types.Config
+
+ // TypeCheckFuncBodies is a predicate over package paths.
+ // A package for which the predicate is false will
+ // have its package-level declarations type checked, but not
+ // its function bodies; this can be used to quickly load
+ // dependencies from source. If nil, all func bodies are type
+ // checked.
+ TypeCheckFuncBodies func(path string) bool
+
+ // If Build is non-nil, it is used to locate source packages.
+ // Otherwise &build.Default is used.
+ //
+ // By default, cgo is invoked to preprocess Go files that
+ // import the fake package "C". This behaviour can be
+ // disabled by setting CGO_ENABLED=0 in the environment prior
+ // to startup, or by setting Build.CgoEnabled=false.
+ Build *build.Context
+
+ // The current directory, used for resolving relative package
+ // references such as "./go/loader". If empty, os.Getwd will be
+ // used instead.
+ Cwd string
+
+ // If DisplayPath is non-nil, it is used to transform each
+ // file name obtained from Build.Import(). This can be used
+ // to prevent a virtualized build.Config's file names from
+ // leaking into the user interface.
+ DisplayPath func(path string) string
+
+ // If AllowErrors is true, Load will return a Program even
+ // if some of the its packages contained I/O, parser or type
+ // errors; such errors are accessible via PackageInfo.Errors. If
+ // false, Load will fail if any package had an error.
+ AllowErrors bool
+
+ // CreatePkgs specifies a list of non-importable initial
+ // packages to create. The resulting packages will appear in
+ // the corresponding elements of the Program.Created slice.
+ CreatePkgs []PkgSpec
+
+ // ImportPkgs specifies a set of initial packages to load.
+ // The map keys are package paths.
+ //
+ // The map value indicates whether to load tests. If true, Load
+ // will add and type-check two lists of files to the package:
+ // non-test files followed by in-package *_test.go files. In
+ // addition, it will append the external test package (if any)
+ // to Program.Created.
+ ImportPkgs map[string]bool
+
+ // FindPackage is called during Load to create the build.Package
+ // for a given import path from a given directory.
+ // If FindPackage is nil, (*build.Context).Import is used.
+ // A client may use this hook to adapt to a proprietary build
+ // system that does not follow the "go build" layout
+ // conventions, for example.
+ //
+ // It must be safe to call concurrently from multiple goroutines.
+ FindPackage func(ctxt *build.Context, importPath, fromDir string, mode build.ImportMode) (*build.Package, error)
+
+ // AfterTypeCheck is called immediately after a list of files
+ // has been type-checked and appended to info.Files.
+ //
+ // This optional hook function is the earliest opportunity for
+ // the client to observe the output of the type checker,
+ // which may be useful to reduce analysis latency when loading
+ // a large program.
+ //
+ // The function is permitted to modify info.Info, for instance
+ // to clear data structures that are no longer needed, which can
+ // dramatically reduce peak memory consumption.
+ //
+ // The function may be called twice for the same PackageInfo:
+ // once for the files of the package and again for the
+ // in-package test files.
+ //
+ // It must be safe to call concurrently from multiple goroutines.
+ AfterTypeCheck func(info *PackageInfo, files []*ast.File)
+}
+
+// A PkgSpec specifies a non-importable package to be created by Load.
+// Files are processed first, but typically only one of Files and
+// Filenames is provided. The path needn't be globally unique.
+//
+// For vendoring purposes, the package's directory is the one that
+// contains the first file.
+type PkgSpec struct {
+ Path string // package path ("" => use package declaration)
+ Files []*ast.File // ASTs of already-parsed files
+ Filenames []string // names of files to be parsed
+}
+
+// A Program is a Go program loaded from source as specified by a Config.
+type Program struct {
+ Fset *token.FileSet // the file set for this program
+
+ // Created[i] contains the initial package whose ASTs or
+ // filenames were supplied by Config.CreatePkgs[i], followed by
+ // the external test package, if any, of each package in
+ // Config.ImportPkgs ordered by ImportPath.
+ //
+ // NOTE: these files must not import "C". Cgo preprocessing is
+ // only performed on imported packages, not ad hoc packages.
+ //
+ // TODO(adonovan): we need to copy and adapt the logic of
+ // goFilesPackage (from $GOROOT/src/cmd/go/build.go) and make
+ // Config.Import and Config.Create methods return the same kind
+ // of entity, essentially a build.Package.
+ // Perhaps we can even reuse that type directly.
+ Created []*PackageInfo
+
+ // Imported contains the initially imported packages,
+ // as specified by Config.ImportPkgs.
+ Imported map[string]*PackageInfo
+
+ // AllPackages contains the PackageInfo of every package
+ // encountered by Load: all initial packages and all
+ // dependencies, including incomplete ones.
+ AllPackages map[*types.Package]*PackageInfo
+
+ // importMap is the canonical mapping of package paths to
+ // packages. It contains all Imported initial packages, but not
+ // Created ones, and all imported dependencies.
+ importMap map[string]*types.Package
+}
+
+// PackageInfo holds the ASTs and facts derived by the type-checker
+// for a single package.
+//
+// Not mutated once exposed via the API.
+//
+type PackageInfo struct {
+ Pkg *types.Package
+ Importable bool // true if 'import "Pkg.Path()"' would resolve to this
+ TransitivelyErrorFree bool // true if Pkg and all its dependencies are free of errors
+ Files []*ast.File // syntax trees for the package's files
+ Errors []error // non-nil if the package had errors
+ types.Info // type-checker deductions.
+ dir string // package directory
+
+ checker *types.Checker // transient type-checker state
+ errorFunc func(error)
+}
+
+func (info *PackageInfo) String() string { return info.Pkg.Path() }
+
+func (info *PackageInfo) appendError(err error) {
+ if info.errorFunc != nil {
+ info.errorFunc(err)
+ } else {
+ fmt.Fprintln(os.Stderr, err)
+ }
+ info.Errors = append(info.Errors, err)
+}
+
+func (conf *Config) fset() *token.FileSet {
+ if conf.Fset == nil {
+ conf.Fset = token.NewFileSet()
+ }
+ return conf.Fset
+}
+
+// ParseFile is a convenience function (intended for testing) that invokes
+// the parser using the Config's FileSet, which is initialized if nil.
+//
+// src specifies the parser input as a string, []byte, or io.Reader, and
+// filename is its apparent name. If src is nil, the contents of
+// filename are read from the file system.
+//
+func (conf *Config) ParseFile(filename string, src interface{}) (*ast.File, error) {
+ // TODO(adonovan): use conf.build() etc like parseFiles does.
+ return parser.ParseFile(conf.fset(), filename, src, conf.ParserMode)
+}
+
+// FromArgsUsage is a partial usage message that applications calling
+// FromArgs may wish to include in their -help output.
+const FromArgsUsage = `
+<args> is a list of arguments denoting a set of initial packages.
+It may take one of two forms:
+
+1. A list of *.go source files.
+
+ All of the specified files are loaded, parsed and type-checked
+ as a single package. All the files must belong to the same directory.
+
+2. A list of import paths, each denoting a package.
+
+ The package's directory is found relative to the $GOROOT and
+ $GOPATH using similar logic to 'go build', and the *.go files in
+ that directory are loaded, parsed and type-checked as a single
+ package.
+
+ In addition, all *_test.go files in the directory are then loaded
+ and parsed. Those files whose package declaration equals that of
+ the non-*_test.go files are included in the primary package. Test
+ files whose package declaration ends with "_test" are type-checked
+ as another package, the 'external' test package, so that a single
+ import path may denote two packages. (Whether this behaviour is
+ enabled is tool-specific, and may depend on additional flags.)
+
+A '--' argument terminates the list of packages.
+`
+
+// FromArgs interprets args as a set of initial packages to load from
+// source and updates the configuration. It returns the list of
+// unconsumed arguments.
+//
+// It is intended for use in command-line interfaces that require a
+// set of initial packages to be specified; see FromArgsUsage message
+// for details.
+//
+// Only superficial errors are reported at this stage; errors dependent
+// on I/O are detected during Load.
+//
+func (conf *Config) FromArgs(args []string, xtest bool) ([]string, error) {
+ var rest []string
+ for i, arg := range args {
+ if arg == "--" {
+ rest = args[i+1:]
+ args = args[:i]
+ break // consume "--" and return the remaining args
+ }
+ }
+
+ if len(args) > 0 && strings.HasSuffix(args[0], ".go") {
+ // Assume args is a list of a *.go files
+ // denoting a single ad hoc package.
+ for _, arg := range args {
+ if !strings.HasSuffix(arg, ".go") {
+ return nil, fmt.Errorf("named files must be .go files: %s", arg)
+ }
+ }
+ conf.CreateFromFilenames("", args...)
+ } else {
+ // Assume args are directories each denoting a
+ // package and (perhaps) an external test, iff xtest.
+ for _, arg := range args {
+ if xtest {
+ conf.ImportWithTests(arg)
+ } else {
+ conf.Import(arg)
+ }
+ }
+ }
+
+ return rest, nil
+}
+
+// CreateFromFilenames is a convenience function that adds
+// a conf.CreatePkgs entry to create a package of the specified *.go
+// files.
+//
+func (conf *Config) CreateFromFilenames(path string, filenames ...string) {
+ conf.CreatePkgs = append(conf.CreatePkgs, PkgSpec{Path: path, Filenames: filenames})
+}
+
+// CreateFromFiles is a convenience function that adds a conf.CreatePkgs
+// entry to create package of the specified path and parsed files.
+//
+func (conf *Config) CreateFromFiles(path string, files ...*ast.File) {
+ conf.CreatePkgs = append(conf.CreatePkgs, PkgSpec{Path: path, Files: files})
+}
+
+// ImportWithTests is a convenience function that adds path to
+// ImportPkgs, the set of initial source packages located relative to
+// $GOPATH. The package will be augmented by any *_test.go files in
+// its directory that contain a "package x" (not "package x_test")
+// declaration.
+//
+// In addition, if any *_test.go files contain a "package x_test"
+// declaration, an additional package comprising just those files will
+// be added to CreatePkgs.
+//
+func (conf *Config) ImportWithTests(path string) { conf.addImport(path, true) }
+
+// Import is a convenience function that adds path to ImportPkgs, the
+// set of initial packages that will be imported from source.
+//
+func (conf *Config) Import(path string) { conf.addImport(path, false) }
+
+func (conf *Config) addImport(path string, tests bool) {
+ if path == "C" {
+ return // ignore; not a real package
+ }
+ if conf.ImportPkgs == nil {
+ conf.ImportPkgs = make(map[string]bool)
+ }
+ conf.ImportPkgs[path] = conf.ImportPkgs[path] || tests
+}
+
+// PathEnclosingInterval returns the PackageInfo and ast.Node that
+// contain source interval [start, end), and all the node's ancestors
+// up to the AST root. It searches all ast.Files of all packages in prog.
+// exact is defined as for astutil.PathEnclosingInterval.
+//
+// The zero value is returned if not found.
+//
+func (prog *Program) PathEnclosingInterval(start, end token.Pos) (pkg *PackageInfo, path []ast.Node, exact bool) {
+ for _, info := range prog.AllPackages {
+ for _, f := range info.Files {
+ if f.Pos() == token.NoPos {
+ // This can happen if the parser saw
+ // too many errors and bailed out.
+ // (Use parser.AllErrors to prevent that.)
+ continue
+ }
+ if !tokenFileContainsPos(prog.Fset.File(f.Pos()), start) {
+ continue
+ }
+ if path, exact := astutil.PathEnclosingInterval(f, start, end); path != nil {
+ return info, path, exact
+ }
+ }
+ }
+ return nil, nil, false
+}
+
+// InitialPackages returns a new slice containing the set of initial
+// packages (Created + Imported) in unspecified order.
+//
+func (prog *Program) InitialPackages() []*PackageInfo {
+ infos := make([]*PackageInfo, 0, len(prog.Created)+len(prog.Imported))
+ infos = append(infos, prog.Created...)
+ for _, info := range prog.Imported {
+ infos = append(infos, info)
+ }
+ return infos
+}
+
+// Package returns the ASTs and results of type checking for the
+// specified package.
+func (prog *Program) Package(path string) *PackageInfo {
+ if info, ok := prog.AllPackages[prog.importMap[path]]; ok {
+ return info
+ }
+ for _, info := range prog.Created {
+ if path == info.Pkg.Path() {
+ return info
+ }
+ }
+ return nil
+}
+
+// ---------- Implementation ----------
+
+// importer holds the working state of the algorithm.
+type importer struct {
+ conf *Config // the client configuration
+ start time.Time // for logging
+
+ progMu sync.Mutex // guards prog
+ prog *Program // the resulting program
+
+ // findpkg is a memoization of FindPackage.
+ findpkgMu sync.Mutex // guards findpkg
+ findpkg map[findpkgKey]*findpkgValue
+
+ importedMu sync.Mutex // guards imported
+ imported map[string]*importInfo // all imported packages (incl. failures) by import path
+
+ // import dependency graph: graph[x][y] => x imports y
+ //
+ // Since non-importable packages cannot be cyclic, we ignore
+ // their imports, thus we only need the subgraph over importable
+ // packages. Nodes are identified by their import paths.
+ graphMu sync.Mutex
+ graph map[string]map[string]bool
+}
+
+type findpkgKey struct {
+ importPath string
+ fromDir string
+ mode build.ImportMode
+}
+
+type findpkgValue struct {
+ ready chan struct{} // closed to broadcast readiness
+ bp *build.Package
+ err error
+}
+
+// importInfo tracks the success or failure of a single import.
+//
+// Upon completion, exactly one of info and err is non-nil:
+// info on successful creation of a package, err otherwise.
+// A successful package may still contain type errors.
+//
+type importInfo struct {
+ path string // import path
+ info *PackageInfo // results of typechecking (including errors)
+ complete chan struct{} // closed to broadcast that info is set.
+}
+
+// awaitCompletion blocks until ii is complete,
+// i.e. the info field is safe to inspect.
+func (ii *importInfo) awaitCompletion() {
+ <-ii.complete // wait for close
+}
+
+// Complete marks ii as complete.
+// Its info and err fields will not be subsequently updated.
+func (ii *importInfo) Complete(info *PackageInfo) {
+ if info == nil {
+ panic("info == nil")
+ }
+ ii.info = info
+ close(ii.complete)
+}
+
+type importError struct {
+ path string // import path
+ err error // reason for failure to create a package
+}
+
+// Load creates the initial packages specified by conf.{Create,Import}Pkgs,
+// loading their dependencies packages as needed.
+//
+// On success, Load returns a Program containing a PackageInfo for
+// each package. On failure, it returns an error.
+//
+// If AllowErrors is true, Load will return a Program even if some
+// packages contained I/O, parser or type errors, or if dependencies
+// were missing. (Such errors are accessible via PackageInfo.Errors. If
+// false, Load will fail if any package had an error.
+//
+// It is an error if no packages were loaded.
+//
+func (conf *Config) Load() (*Program, error) {
+ // Create a simple default error handler for parse/type errors.
+ if conf.TypeChecker.Error == nil {
+ conf.TypeChecker.Error = func(e error) { fmt.Fprintln(os.Stderr, e) }
+ }
+
+ // Set default working directory for relative package references.
+ if conf.Cwd == "" {
+ var err error
+ conf.Cwd, err = os.Getwd()
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ // Install default FindPackage hook using go/build logic.
+ if conf.FindPackage == nil {
+ conf.FindPackage = (*build.Context).Import
+ }
+
+ prog := &Program{
+ Fset: conf.fset(),
+ Imported: make(map[string]*PackageInfo),
+ importMap: make(map[string]*types.Package),
+ AllPackages: make(map[*types.Package]*PackageInfo),
+ }
+
+ imp := importer{
+ conf: conf,
+ prog: prog,
+ findpkg: make(map[findpkgKey]*findpkgValue),
+ imported: make(map[string]*importInfo),
+ start: time.Now(),
+ graph: make(map[string]map[string]bool),
+ }
+
+ // -- loading proper (concurrent phase) --------------------------------
+
+ var errpkgs []string // packages that contained errors
+
+ // Load the initially imported packages and their dependencies,
+ // in parallel.
+ // No vendor check on packages imported from the command line.
+ infos, importErrors := imp.importAll("", conf.Cwd, conf.ImportPkgs, ignoreVendor)
+ for _, ie := range importErrors {
+ conf.TypeChecker.Error(ie.err) // failed to create package
+ errpkgs = append(errpkgs, ie.path)
+ }
+ for _, info := range infos {
+ prog.Imported[info.Pkg.Path()] = info
+ }
+
+ // Augment the designated initial packages by their tests.
+ // Dependencies are loaded in parallel.
+ var xtestPkgs []*build.Package
+ for importPath, augment := range conf.ImportPkgs {
+ if !augment {
+ continue
+ }
+
+ // No vendor check on packages imported from command line.
+ bp, err := imp.findPackage(importPath, conf.Cwd, ignoreVendor)
+ if err != nil {
+ // Package not found, or can't even parse package declaration.
+ // Already reported by previous loop; ignore it.
+ continue
+ }
+
+ // Needs external test package?
+ if len(bp.XTestGoFiles) > 0 {
+ xtestPkgs = append(xtestPkgs, bp)
+ }
+
+ // Consult the cache using the canonical package path.
+ path := bp.ImportPath
+ imp.importedMu.Lock() // (unnecessary, we're sequential here)
+ ii, ok := imp.imported[path]
+ // Paranoid checks added due to issue #11012.
+ if !ok {
+ // Unreachable.
+ // The previous loop called importAll and thus
+ // startLoad for each path in ImportPkgs, which
+ // populates imp.imported[path] with a non-zero value.
+ panic(fmt.Sprintf("imported[%q] not found", path))
+ }
+ if ii == nil {
+ // Unreachable.
+ // The ii values in this loop are the same as in
+ // the previous loop, which enforced the invariant
+ // that at least one of ii.err and ii.info is non-nil.
+ panic(fmt.Sprintf("imported[%q] == nil", path))
+ }
+ if ii.info == nil {
+ // Unreachable.
+ // awaitCompletion has the postcondition
+ // ii.info != nil.
+ panic(fmt.Sprintf("imported[%q].info = nil", path))
+ }
+ info := ii.info
+ imp.importedMu.Unlock()
+
+ // Parse the in-package test files.
+ files, errs := imp.conf.parsePackageFiles(bp, 't')
+ for _, err := range errs {
+ info.appendError(err)
+ }
+
+ // The test files augmenting package P cannot be imported,
+ // but may import packages that import P,
+ // so we must disable the cycle check.
+ imp.addFiles(info, files, false)
+ }
+
+ createPkg := func(path, dir string, files []*ast.File, errs []error) {
+ info := imp.newPackageInfo(path, dir)
+ for _, err := range errs {
+ info.appendError(err)
+ }
+
+ // Ad hoc packages are non-importable,
+ // so no cycle check is needed.
+ // addFiles loads dependencies in parallel.
+ imp.addFiles(info, files, false)
+ prog.Created = append(prog.Created, info)
+ }
+
+ // Create packages specified by conf.CreatePkgs.
+ for _, cp := range conf.CreatePkgs {
+ files, errs := parseFiles(conf.fset(), conf.build(), nil, conf.Cwd, cp.Filenames, conf.ParserMode)
+ files = append(files, cp.Files...)
+
+ path := cp.Path
+ if path == "" {
+ if len(files) > 0 {
+ path = files[0].Name.Name
+ } else {
+ path = "(unnamed)"
+ }
+ }
+
+ dir := conf.Cwd
+ if len(files) > 0 && files[0].Pos().IsValid() {
+ dir = filepath.Dir(conf.fset().File(files[0].Pos()).Name())
+ }
+ createPkg(path, dir, files, errs)
+ }
+
+ // Create external test packages.
+ sort.Sort(byImportPath(xtestPkgs))
+ for _, bp := range xtestPkgs {
+ files, errs := imp.conf.parsePackageFiles(bp, 'x')
+ createPkg(bp.ImportPath+"_test", bp.Dir, files, errs)
+ }
+
+ // -- finishing up (sequential) ----------------------------------------
+
+ if len(prog.Imported)+len(prog.Created) == 0 {
+ return nil, errors.New("no initial packages were loaded")
+ }
+
+ // Create infos for indirectly imported packages.
+ // e.g. incomplete packages without syntax, loaded from export data.
+ for _, obj := range prog.importMap {
+ info := prog.AllPackages[obj]
+ if info == nil {
+ prog.AllPackages[obj] = &PackageInfo{Pkg: obj, Importable: true}
+ } else {
+ // finished
+ info.checker = nil
+ info.errorFunc = nil
+ }
+ }
+
+ if !conf.AllowErrors {
+ // Report errors in indirectly imported packages.
+ for _, info := range prog.AllPackages {
+ if len(info.Errors) > 0 {
+ errpkgs = append(errpkgs, info.Pkg.Path())
+ }
+ }
+ if errpkgs != nil {
+ var more string
+ if len(errpkgs) > 3 {
+ more = fmt.Sprintf(" and %d more", len(errpkgs)-3)
+ errpkgs = errpkgs[:3]
+ }
+ return nil, fmt.Errorf("couldn't load packages due to errors: %s%s",
+ strings.Join(errpkgs, ", "), more)
+ }
+ }
+
+ markErrorFreePackages(prog.AllPackages)
+
+ return prog, nil
+}
+
+type byImportPath []*build.Package
+
+func (b byImportPath) Len() int { return len(b) }
+func (b byImportPath) Less(i, j int) bool { return b[i].ImportPath < b[j].ImportPath }
+func (b byImportPath) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
+
+// markErrorFreePackages sets the TransitivelyErrorFree flag on all
+// applicable packages.
+func markErrorFreePackages(allPackages map[*types.Package]*PackageInfo) {
+ // Build the transpose of the import graph.
+ importedBy := make(map[*types.Package]map[*types.Package]bool)
+ for P := range allPackages {
+ for _, Q := range P.Imports() {
+ clients, ok := importedBy[Q]
+ if !ok {
+ clients = make(map[*types.Package]bool)
+ importedBy[Q] = clients
+ }
+ clients[P] = true
+ }
+ }
+
+ // Find all packages reachable from some error package.
+ reachable := make(map[*types.Package]bool)
+ var visit func(*types.Package)
+ visit = func(p *types.Package) {
+ if !reachable[p] {
+ reachable[p] = true
+ for q := range importedBy[p] {
+ visit(q)
+ }
+ }
+ }
+ for _, info := range allPackages {
+ if len(info.Errors) > 0 {
+ visit(info.Pkg)
+ }
+ }
+
+ // Mark the others as "transitively error-free".
+ for _, info := range allPackages {
+ if !reachable[info.Pkg] {
+ info.TransitivelyErrorFree = true
+ }
+ }
+}
+
+// build returns the effective build context.
+func (conf *Config) build() *build.Context {
+ if conf.Build != nil {
+ return conf.Build
+ }
+ return &build.Default
+}
+
+// parsePackageFiles enumerates the files belonging to package path,
+// then loads, parses and returns them, plus a list of I/O or parse
+// errors that were encountered.
+//
+// 'which' indicates which files to include:
+// 'g': include non-test *.go source files (GoFiles + processed CgoFiles)
+// 't': include in-package *_test.go source files (TestGoFiles)
+// 'x': include external *_test.go source files. (XTestGoFiles)
+//
+func (conf *Config) parsePackageFiles(bp *build.Package, which rune) ([]*ast.File, []error) {
+ if bp.ImportPath == "unsafe" {
+ return nil, nil
+ }
+ var filenames []string
+ switch which {
+ case 'g':
+ filenames = bp.GoFiles
+ case 't':
+ filenames = bp.TestGoFiles
+ case 'x':
+ filenames = bp.XTestGoFiles
+ default:
+ panic(which)
+ }
+
+ files, errs := parseFiles(conf.fset(), conf.build(), conf.DisplayPath, bp.Dir, filenames, conf.ParserMode)
+
+ // Preprocess CgoFiles and parse the outputs (sequentially).
+ if which == 'g' && bp.CgoFiles != nil {
+ cgofiles, err := cgo.ProcessFiles(bp, conf.fset(), conf.DisplayPath, conf.ParserMode)
+ if err != nil {
+ errs = append(errs, err)
+ } else {
+ files = append(files, cgofiles...)
+ }
+ }
+
+ return files, errs
+}
+
+// doImport imports the package denoted by path.
+// It implements the types.Importer signature.
+//
+// It returns an error if a package could not be created
+// (e.g. go/build or parse error), but type errors are reported via
+// the types.Config.Error callback (the first of which is also saved
+// in the package's PackageInfo).
+//
+// Idempotent.
+//
+func (imp *importer) doImport(from *PackageInfo, to string) (*types.Package, error) {
+ if to == "C" {
+ // This should be unreachable, but ad hoc packages are
+ // not currently subject to cgo preprocessing.
+ // See https://github.com/golang/go/issues/11627.
+ return nil, fmt.Errorf(`the loader doesn't cgo-process ad hoc packages like %q; see Go issue 11627`,
+ from.Pkg.Path())
+ }
+
+ bp, err := imp.findPackage(to, from.dir, 0)
+ if err != nil {
+ return nil, err
+ }
+
+ // The standard unsafe package is handled specially,
+ // and has no PackageInfo.
+ if bp.ImportPath == "unsafe" {
+ return types.Unsafe, nil
+ }
+
+ // Look for the package in the cache using its canonical path.
+ path := bp.ImportPath
+ imp.importedMu.Lock()
+ ii := imp.imported[path]
+ imp.importedMu.Unlock()
+ if ii == nil {
+ panic("internal error: unexpected import: " + path)
+ }
+ if ii.info != nil {
+ return ii.info.Pkg, nil
+ }
+
+ // Import of incomplete package: this indicates a cycle.
+ fromPath := from.Pkg.Path()
+ if cycle := imp.findPath(path, fromPath); cycle != nil {
+ cycle = append([]string{fromPath}, cycle...)
+ return nil, fmt.Errorf("import cycle: %s", strings.Join(cycle, " -> "))
+ }
+
+ panic("internal error: import of incomplete (yet acyclic) package: " + fromPath)
+}
+
+// findPackage locates the package denoted by the importPath in the
+// specified directory.
+func (imp *importer) findPackage(importPath, fromDir string, mode build.ImportMode) (*build.Package, error) {
+ // We use a non-blocking duplicate-suppressing cache (gopl.io §9.7)
+ // to avoid holding the lock around FindPackage.
+ key := findpkgKey{importPath, fromDir, mode}
+ imp.findpkgMu.Lock()
+ v, ok := imp.findpkg[key]
+ if ok {
+ // cache hit
+ imp.findpkgMu.Unlock()
+
+ <-v.ready // wait for entry to become ready
+ } else {
+ // Cache miss: this goroutine becomes responsible for
+ // populating the map entry and broadcasting its readiness.
+ v = &findpkgValue{ready: make(chan struct{})}
+ imp.findpkg[key] = v
+ imp.findpkgMu.Unlock()
+
+ ioLimit <- true
+ v.bp, v.err = imp.conf.FindPackage(imp.conf.build(), importPath, fromDir, mode)
+ <-ioLimit
+
+ if _, ok := v.err.(*build.NoGoError); ok {
+ v.err = nil // empty directory is not an error
+ }
+
+ close(v.ready) // broadcast ready condition
+ }
+ return v.bp, v.err
+}
+
+// importAll loads, parses, and type-checks the specified packages in
+// parallel and returns their completed importInfos in unspecified order.
+//
+// fromPath is the package path of the importing package, if it is
+// importable, "" otherwise. It is used for cycle detection.
+//
+// fromDir is the directory containing the import declaration that
+// caused these imports.
+//
+func (imp *importer) importAll(fromPath, fromDir string, imports map[string]bool, mode build.ImportMode) (infos []*PackageInfo, errors []importError) {
+ // TODO(adonovan): opt: do the loop in parallel once
+ // findPackage is non-blocking.
+ var pending []*importInfo
+ for importPath := range imports {
+ bp, err := imp.findPackage(importPath, fromDir, mode)
+ if err != nil {
+ errors = append(errors, importError{
+ path: importPath,
+ err: err,
+ })
+ continue
+ }
+ pending = append(pending, imp.startLoad(bp))
+ }
+
+ if fromPath != "" {
+ // We're loading a set of imports.
+ //
+ // We must record graph edges from the importing package
+ // to its dependencies, and check for cycles.
+ imp.graphMu.Lock()
+ deps, ok := imp.graph[fromPath]
+ if !ok {
+ deps = make(map[string]bool)
+ imp.graph[fromPath] = deps
+ }
+ for _, ii := range pending {
+ deps[ii.path] = true
+ }
+ imp.graphMu.Unlock()
+ }
+
+ for _, ii := range pending {
+ if fromPath != "" {
+ if cycle := imp.findPath(ii.path, fromPath); cycle != nil {
+ // Cycle-forming import: we must not await its
+ // completion since it would deadlock.
+ //
+ // We don't record the error in ii since
+ // the error is really associated with the
+ // cycle-forming edge, not the package itself.
+ // (Also it would complicate the
+ // invariants of importPath completion.)
+ if trace {
+ fmt.Fprintf(os.Stderr, "import cycle: %q\n", cycle)
+ }
+ continue
+ }
+ }
+ ii.awaitCompletion()
+ infos = append(infos, ii.info)
+ }
+
+ return infos, errors
+}
+
+// findPath returns an arbitrary path from 'from' to 'to' in the import
+// graph, or nil if there was none.
+func (imp *importer) findPath(from, to string) []string {
+ imp.graphMu.Lock()
+ defer imp.graphMu.Unlock()
+
+ seen := make(map[string]bool)
+ var search func(stack []string, importPath string) []string
+ search = func(stack []string, importPath string) []string {
+ if !seen[importPath] {
+ seen[importPath] = true
+ stack = append(stack, importPath)
+ if importPath == to {
+ return stack
+ }
+ for x := range imp.graph[importPath] {
+ if p := search(stack, x); p != nil {
+ return p
+ }
+ }
+ }
+ return nil
+ }
+ return search(make([]string, 0, 20), from)
+}
+
+// startLoad initiates the loading, parsing and type-checking of the
+// specified package and its dependencies, if it has not already begun.
+//
+// It returns an importInfo, not necessarily in a completed state. The
+// caller must call awaitCompletion() before accessing its info field.
+//
+// startLoad is concurrency-safe and idempotent.
+//
+func (imp *importer) startLoad(bp *build.Package) *importInfo {
+ path := bp.ImportPath
+ imp.importedMu.Lock()
+ ii, ok := imp.imported[path]
+ if !ok {
+ ii = &importInfo{path: path, complete: make(chan struct{})}
+ imp.imported[path] = ii
+ go func() {
+ info := imp.load(bp)
+ ii.Complete(info)
+ }()
+ }
+ imp.importedMu.Unlock()
+
+ return ii
+}
+
+// load implements package loading by parsing Go source files
+// located by go/build.
+func (imp *importer) load(bp *build.Package) *PackageInfo {
+ info := imp.newPackageInfo(bp.ImportPath, bp.Dir)
+ info.Importable = true
+ files, errs := imp.conf.parsePackageFiles(bp, 'g')
+ for _, err := range errs {
+ info.appendError(err)
+ }
+
+ imp.addFiles(info, files, true)
+
+ imp.progMu.Lock()
+ imp.prog.importMap[bp.ImportPath] = info.Pkg
+ imp.progMu.Unlock()
+
+ return info
+}
+
+// addFiles adds and type-checks the specified files to info, loading
+// their dependencies if needed. The order of files determines the
+// package initialization order. It may be called multiple times on the
+// same package. Errors are appended to the info.Errors field.
+//
+// cycleCheck determines whether the imports within files create
+// dependency edges that should be checked for potential cycles.
+//
+func (imp *importer) addFiles(info *PackageInfo, files []*ast.File, cycleCheck bool) {
+ // Ensure the dependencies are loaded, in parallel.
+ var fromPath string
+ if cycleCheck {
+ fromPath = info.Pkg.Path()
+ }
+ // TODO(adonovan): opt: make the caller do scanImports.
+ // Callers with a build.Package can skip it.
+ imp.importAll(fromPath, info.dir, scanImports(files), 0)
+
+ if trace {
+ fmt.Fprintf(os.Stderr, "%s: start %q (%d)\n",
+ time.Since(imp.start), info.Pkg.Path(), len(files))
+ }
+
+ // Don't call checker.Files on Unsafe, even with zero files,
+ // because it would mutate the package, which is a global.
+ if info.Pkg == types.Unsafe {
+ if len(files) > 0 {
+ panic(`"unsafe" package contains unexpected files`)
+ }
+ } else {
+ // Ignore the returned (first) error since we
+ // already collect them all in the PackageInfo.
+ info.checker.Files(files)
+ info.Files = append(info.Files, files...)
+ }
+
+ if imp.conf.AfterTypeCheck != nil {
+ imp.conf.AfterTypeCheck(info, files)
+ }
+
+ if trace {
+ fmt.Fprintf(os.Stderr, "%s: stop %q\n",
+ time.Since(imp.start), info.Pkg.Path())
+ }
+}
+
+func (imp *importer) newPackageInfo(path, dir string) *PackageInfo {
+ var pkg *types.Package
+ if path == "unsafe" {
+ pkg = types.Unsafe
+ } else {
+ pkg = types.NewPackage(path, "")
+ }
+ info := &PackageInfo{
+ Pkg: pkg,
+ Info: types.Info{
+ Types: make(map[ast.Expr]types.TypeAndValue),
+ Defs: make(map[*ast.Ident]types.Object),
+ Uses: make(map[*ast.Ident]types.Object),
+ Implicits: make(map[ast.Node]types.Object),
+ Scopes: make(map[ast.Node]*types.Scope),
+ Selections: make(map[*ast.SelectorExpr]*types.Selection),
+ },
+ errorFunc: imp.conf.TypeChecker.Error,
+ dir: dir,
+ }
+
+ // Copy the types.Config so we can vary it across PackageInfos.
+ tc := imp.conf.TypeChecker
+ tc.IgnoreFuncBodies = false
+ if f := imp.conf.TypeCheckFuncBodies; f != nil {
+ tc.IgnoreFuncBodies = !f(path)
+ }
+ tc.Importer = closure{imp, info}
+ tc.Error = info.appendError // appendError wraps the user's Error function
+
+ info.checker = types.NewChecker(&tc, imp.conf.fset(), pkg, &info.Info)
+ imp.progMu.Lock()
+ imp.prog.AllPackages[pkg] = info
+ imp.progMu.Unlock()
+ return info
+}
+
+type closure struct {
+ imp *importer
+ info *PackageInfo
+}
+
+func (c closure) Import(to string) (*types.Package, error) { return c.imp.doImport(c.info, to) }
diff --git a/vendor/golang.org/x/tools/go/loader/util.go b/vendor/golang.org/x/tools/go/loader/util.go
new file mode 100644
index 00000000..7f38dd74
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/loader/util.go
@@ -0,0 +1,124 @@
+// 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 loader
+
+import (
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "io"
+ "os"
+ "strconv"
+ "sync"
+
+ "golang.org/x/tools/go/buildutil"
+)
+
+// We use a counting semaphore to limit
+// the number of parallel I/O calls per process.
+var ioLimit = make(chan bool, 10)
+
+// parseFiles parses the Go source files within directory dir and
+// returns the ASTs of the ones that could be at least partially parsed,
+// along with a list of I/O and parse errors encountered.
+//
+// I/O is done via ctxt, which may specify a virtual file system.
+// displayPath is used to transform the filenames attached to the ASTs.
+//
+func parseFiles(fset *token.FileSet, ctxt *build.Context, displayPath func(string) string, dir string, files []string, mode parser.Mode) ([]*ast.File, []error) {
+ if displayPath == nil {
+ displayPath = func(path string) string { return path }
+ }
+ var wg sync.WaitGroup
+ n := len(files)
+ parsed := make([]*ast.File, n)
+ errors := make([]error, n)
+ for i, file := range files {
+ if !buildutil.IsAbsPath(ctxt, file) {
+ file = buildutil.JoinPath(ctxt, dir, file)
+ }
+ wg.Add(1)
+ go func(i int, file string) {
+ ioLimit <- true // wait
+ defer func() {
+ wg.Done()
+ <-ioLimit // signal
+ }()
+ var rd io.ReadCloser
+ var err error
+ if ctxt.OpenFile != nil {
+ rd, err = ctxt.OpenFile(file)
+ } else {
+ rd, err = os.Open(file)
+ }
+ if err != nil {
+ errors[i] = err // open failed
+ return
+ }
+
+ // ParseFile may return both an AST and an error.
+ parsed[i], errors[i] = parser.ParseFile(fset, displayPath(file), rd, mode)
+ rd.Close()
+ }(i, file)
+ }
+ wg.Wait()
+
+ // Eliminate nils, preserving order.
+ var o int
+ for _, f := range parsed {
+ if f != nil {
+ parsed[o] = f
+ o++
+ }
+ }
+ parsed = parsed[:o]
+
+ o = 0
+ for _, err := range errors {
+ if err != nil {
+ errors[o] = err
+ o++
+ }
+ }
+ errors = errors[:o]
+
+ return parsed, errors
+}
+
+// scanImports returns the set of all import paths from all
+// import specs in the specified files.
+func scanImports(files []*ast.File) map[string]bool {
+ imports := make(map[string]bool)
+ for _, f := range files {
+ for _, decl := range f.Decls {
+ if decl, ok := decl.(*ast.GenDecl); ok && decl.Tok == token.IMPORT {
+ for _, spec := range decl.Specs {
+ spec := spec.(*ast.ImportSpec)
+
+ // NB: do not assume the program is well-formed!
+ path, err := strconv.Unquote(spec.Path.Value)
+ if err != nil {
+ continue // quietly ignore the error
+ }
+ if path == "C" {
+ continue // skip pseudopackage
+ }
+ imports[path] = true
+ }
+ }
+ }
+ }
+ return imports
+}
+
+// ---------- Internal helpers ----------
+
+// TODO(adonovan): make this a method: func (*token.File) Contains(token.Pos)
+func tokenFileContainsPos(f *token.File, pos token.Pos) bool {
+ p := int(pos)
+ base := f.Base()
+ return base <= p && p < base+f.Size()
+}
generated by cgit (git 2.34.1) at 2024-10-19 15:47:34 +0000