diff --git a/Makefile b/Makefile
index 11ecbc74..97bc9041 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,8 @@ MSI_VERSION := $(shell git tag -l --sort=v:refname | grep "w" | tail -1 | cut
#MSI_VERSION expects the format of the tag to be: (wX.X.X). Starts with the w character to not break cfsetup.
#e.g. w3.0.1 or w4.2.10. It trims off the w character when creating the MSI.
+GO_SUMTYPE := go run -mod=vendor github.com/sudarshan-reddy/go-sumtype
+
ifeq ($(ORIGINAL_NAME), true)
# Used for builds that want FIPS compilation but want the artifacts generated to still have the original name.
BINARY_NAME := cloudflared
@@ -271,12 +273,8 @@ quic-deps:
.PHONY: vet
vet:
go vet -mod=vendor ./...
- # go get github.com/sudarshan-reddy/go-sumtype (don't do this in build directory or this will cause vendor issues)
- # Note: If you have github.com/BurntSushi/go-sumtype then you might have to use the repo above instead
- # for now because it uses an older version of golang.org/x/tools.
- which go-sumtype
- go-sumtype $$(go list -mod=vendor ./...)
+ $(GO_SUMTYPE) $$(go list -mod=vendor ./...)
.PHONY: goimports
goimports:
- for d in $$(go list -mod=readonly -f '{{.Dir}}' -a ./... | fgrep -v tunnelrpc) ; do goimports -format-only -local github.com/cloudflare/cloudflared -w $$d ; done
\ No newline at end of file
+ for d in $$(go list -mod=readonly -f '{{.Dir}}' -a ./... | fgrep -v tunnelrpc) ; do goimports -format-only -local github.com/cloudflare/cloudflared -w $$d ; done
diff --git a/go.mod b/go.mod
index 59b8ec7c..9c612dc8 100644
--- a/go.mod
+++ b/go.mod
@@ -41,6 +41,7 @@ require (
github.com/rs/zerolog v1.20.0
github.com/russross/blackfriday/v2 v2.1.0 // indirect
github.com/stretchr/testify v1.7.0
+ github.com/sudarshan-reddy/go-sumtype v0.0.0-20210827105221-82eca7e5abb1
github.com/urfave/cli/v2 v2.3.0
go.uber.org/automaxprocs v1.4.0
golang.org/x/crypto v0.0.0-20210921155107-089bfa567519
diff --git a/go.sum b/go.sum
index ed534dcb..c0ef2fe4 100644
--- a/go.sum
+++ b/go.sum
@@ -562,6 +562,8 @@ github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5
github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/sudarshan-reddy/go-sumtype v0.0.0-20210827105221-82eca7e5abb1 h1:PfYPROl/6Zyspmiebusz0s/Bsr/Ju/U9TFwkPqzdL3U=
+github.com/sudarshan-reddy/go-sumtype v0.0.0-20210827105221-82eca7e5abb1/go.mod h1:g+9pWOY/CQta4Y1Z7oTU9BcBGs2awNSLJ4aBRyvG784=
github.com/tarm/serial v0.0.0-20180830185346-98f6abe2eb07/go.mod h1:kDXzergiv9cbyO7IOYJZWg1U88JhDg3PB6klq9Hg2pA=
github.com/tinylib/msgp v1.1.2 h1:gWmO7n0Ys2RBEb7GPYB9Ujq8Mk5p2U08lRnmMcGy6BQ=
github.com/tinylib/msgp v1.1.2/go.mod h1:+d+yLhGm8mzTaHzB+wgMYrodPfmZrzkirds8fDWklFE=
diff --git a/tools/tools.go b/tools/tools.go
new file mode 100644
index 00000000..309965d0
--- /dev/null
+++ b/tools/tools.go
@@ -0,0 +1,7 @@
+//go:build tools
+
+package tools
+
+import (
+ _ "github.com/sudarshan-reddy/go-sumtype"
+)
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/.travis.yml b/vendor/github.com/sudarshan-reddy/go-sumtype/.travis.yml
new file mode 100644
index 00000000..4f2ee4d9
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/.travis.yml
@@ -0,0 +1 @@
+language: go
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/COPYING b/vendor/github.com/sudarshan-reddy/go-sumtype/COPYING
new file mode 100644
index 00000000..bb9c20a0
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/COPYING
@@ -0,0 +1,3 @@
+This project is dual-licensed under the Unlicense and MIT licenses.
+
+You may use this code under the terms of either license.
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/LICENSE-MIT b/vendor/github.com/sudarshan-reddy/go-sumtype/LICENSE-MIT
new file mode 100644
index 00000000..3b0a5dc0
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/LICENSE-MIT
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Andrew Gallant
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/README.md b/vendor/github.com/sudarshan-reddy/go-sumtype/README.md
new file mode 100644
index 00000000..801291e4
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/README.md
@@ -0,0 +1,124 @@
+go-sumtype
+==========
+A simple utility for running exhaustiveness checks on type switch statements.
+Exhaustiveness checks are only run on interfaces that are declared to be
+"sum types."
+
+[![Linux build status](https://api.travis-ci.org/BurntSushi/go-sumtype.png)](https://travis-ci.org/BurntSushi/go-sumtype)
+
+Dual-licensed under MIT or the [UNLICENSE](http://unlicense.org).
+
+This work was inspired by our code at
+[Diffeo](https://diffeo.com).
+
+### Installation
+
+```go
+$ go get github.com/BurntSushi/go-sumtype
+```
+
+For usage info, just run the command:
+
+```
+$ go-sumtype
+```
+
+Typical usage might look like this:
+
+```
+$ go-sumtype $(go list ./... | grep -v vendor)
+```
+
+### Usage
+
+go-sumtype takes a list of Go package paths or files and looks for sum type
+declarations in each package/file provided. Exhaustiveness checks are then
+performed for each use of a declared sum type in a type switch statement.
+Namely, `go-sumtype` will report an error for any type switch statement that
+either lacks a `default` clause or does not account for all possible variants.
+
+Declarations are provided in comments like so:
+
+```
+//go-sumtype:decl MySumType
+```
+
+`MySumType` must satisfy the following:
+
+1. It is a type defined in the same package.
+2. It is an interface.
+3. It is *sealed*. That is, part of its interface definition contains an
+ unexported method.
+
+`go-sumtype` will produce an error if any of the above is not true.
+
+For valid declarations, `go-sumtype` will look for all occurrences in which a
+value of type `MySumType` participates in a type switch statement. In those
+occurrences, it will attempt to detect whether the type switch is exhaustive
+or not. If it's not, `go-sumtype` will report an error. For example, running
+`go-sumtype` on this source file:
+
+```go
+package main
+
+//go-sumtype:decl MySumType
+
+type MySumType interface {
+ sealed()
+}
+
+type VariantA struct{}
+
+func (*VariantA) sealed() {}
+
+type VariantB struct{}
+
+func (*VariantB) sealed() {}
+
+func main() {
+ switch MySumType(nil).(type) {
+ case *VariantA:
+ }
+}
+```
+
+produces the following:
+
+```
+$ go-sumtype mysumtype.go
+mysumtype.go:18:2: exhaustiveness check failed for sum type 'MySumType': missing cases for VariantB
+```
+
+Adding either a `default` clause or a clause to handle `*VariantB` will cause
+exhaustive checks to pass.
+
+As a special case, if the type switch statement contains a `default` clause
+that always panics, then exhaustiveness checks are still performed.
+
+### Details and motivation
+
+Sum types are otherwise known as discriminated unions. That is, a sum type is
+a finite set of disjoint values. In type systems that support sum types, the
+language will guarantee that if one has a sum type `T`, then its value must
+be one of its variants.
+
+Go's type system does not support sum types. A typical proxy for representing
+sum types in Go is to use an interface with an unexported method and define
+each variant of the sum type in the same package to satisfy said interface.
+This guarantees that the set of types that satisfy the interface is closed
+at compile time. Performing case analysis on these types is then done with
+a type switch statement, e.g., `switch x.(type) { ... }`. Each clause of the
+type switch corresponds to a *variant* of the sum type. The downside of this
+approach is that Go's type system is not aware of the set of variants, so it
+cannot tell you whether case analysis over a sum type is complete or not.
+
+The `go-sumtype` command recognizes this pattern, but it needs a small amount
+of help to recognize which interfaces should be treated as sum types, which
+is why the `//go-sumtype:decl ...` annotation is required. `go-sumtype` will
+figure out all of the variants of a sum type by finding the set of types
+defined in the same package that satisfy the interface specified by the
+declaration.
+
+The `go-sumtype` command will prove its worth when you need to add a variant
+to an existing sum type. Running `go-sumtype` will tell you immediately which
+case analyses need to be updated to account for the new variant.
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/UNLICENSE b/vendor/github.com/sudarshan-reddy/go-sumtype/UNLICENSE
new file mode 100644
index 00000000..68a49daa
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/UNLICENSE
@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/check.go b/vendor/github.com/sudarshan-reddy/go-sumtype/check.go
new file mode 100644
index 00000000..4167af14
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/check.go
@@ -0,0 +1,183 @@
+package main
+
+import (
+ "fmt"
+ "go/ast"
+ "go/token"
+ "go/types"
+ "sort"
+ "strings"
+
+ "golang.org/x/tools/go/packages"
+)
+
+// inexhaustiveError is returned from check for each occurrence of inexhaustive
+// case analysis in a Go type switch statement.
+type inexhaustiveError struct {
+ Pos token.Position
+ Def sumTypeDef
+ Missing []types.Object
+}
+
+func (e inexhaustiveError) Error() string {
+ return fmt.Sprintf(
+ "%s: exhaustiveness check failed for sum type '%s': missing cases for %s",
+ e.Pos, e.Def.Decl.TypeName, strings.Join(e.Names(), ", "))
+}
+
+// Names returns a sorted list of names corresponding to the missing variant
+// cases.
+func (e inexhaustiveError) Names() []string {
+ var list []string
+ for _, o := range e.Missing {
+ list = append(list, o.Name())
+ }
+ sort.Sort(sort.StringSlice(list))
+ return list
+}
+
+// check does exhaustiveness checking for the given sum type definitions in the
+// given package. Every instance of inexhaustive case analysis is returned.
+func check(pkg *packages.Package, defs []sumTypeDef) []error {
+ var errs []error
+ for _, astfile := range pkg.Syntax {
+ ast.Inspect(astfile, func(n ast.Node) bool {
+ swtch, ok := n.(*ast.TypeSwitchStmt)
+ if !ok {
+ return true
+ }
+ if err := checkSwitch(pkg, defs, swtch); err != nil {
+ errs = append(errs, err)
+ }
+ return true
+ })
+ }
+ return errs
+}
+
+// checkSwitch performs an exhaustiveness check on the given type switch
+// statement. If the type switch is used on a sum type and does not cover
+// all variants of that sum type, then an error is returned indicating which
+// variants were missed.
+//
+// Note that if the type switch contains a non-panicing default case, then
+// exhaustiveness checks are disabled.
+func checkSwitch(
+ pkg *packages.Package,
+ defs []sumTypeDef,
+ swtch *ast.TypeSwitchStmt,
+) error {
+ def, missing := missingVariantsInSwitch(pkg, defs, swtch)
+ if len(missing) > 0 {
+ return inexhaustiveError{
+ Pos: pkg.Fset.Position(swtch.Pos()),
+ Def: *def,
+ Missing: missing,
+ }
+ }
+ return nil
+}
+
+// missingVariantsInSwitch returns a list of missing variants corresponding to
+// the given switch statement. The corresponding sum type definition is also
+// returned. (If no sum type definition could be found, then no exhaustiveness
+// checks are performed, and therefore, no missing variants are returned.)
+func missingVariantsInSwitch(
+ pkg *packages.Package,
+ defs []sumTypeDef,
+ swtch *ast.TypeSwitchStmt,
+) (*sumTypeDef, []types.Object) {
+ asserted := findTypeAssertExpr(swtch)
+ ty := pkg.TypesInfo.TypeOf(asserted)
+ def := findDef(defs, ty)
+ if def == nil {
+ // We couldn't find a corresponding sum type, so there's
+ // nothing we can do to check it.
+ return nil, nil
+ }
+ variantExprs, hasDefault := switchVariants(swtch)
+ if hasDefault && !defaultClauseAlwaysPanics(swtch) {
+ // A catch-all case defeats all exhaustiveness checks.
+ return def, nil
+ }
+ var variantTypes []types.Type
+ for _, expr := range variantExprs {
+ variantTypes = append(variantTypes, pkg.TypesInfo.TypeOf(expr))
+ }
+ return def, def.missing(variantTypes)
+}
+
+// switchVariants returns all case expressions found in a type switch. This
+// includes expressions from cases that have a list of expressions.
+func switchVariants(swtch *ast.TypeSwitchStmt) (exprs []ast.Expr, hasDefault bool) {
+ for _, stmt := range swtch.Body.List {
+ clause := stmt.(*ast.CaseClause)
+ if clause.List == nil {
+ hasDefault = true
+ } else {
+ exprs = append(exprs, clause.List...)
+ }
+ }
+ return
+}
+
+// defaultClauseAlwaysPanics returns true if the given switch statement has a
+// default clause that always panics. Note that this is done on a best-effort
+// basis. While there will never be any false positives, there may be false
+// negatives.
+//
+// If the given switch statement has no default clause, then this function
+// panics.
+func defaultClauseAlwaysPanics(swtch *ast.TypeSwitchStmt) bool {
+ var clause *ast.CaseClause
+ for _, stmt := range swtch.Body.List {
+ c := stmt.(*ast.CaseClause)
+ if c.List == nil {
+ clause = c
+ break
+ }
+ }
+ if clause == nil {
+ panic("switch statement has no default clause")
+ }
+ if len(clause.Body) != 1 {
+ return false
+ }
+ exprStmt, ok := clause.Body[0].(*ast.ExprStmt)
+ if !ok {
+ return false
+ }
+ callExpr, ok := exprStmt.X.(*ast.CallExpr)
+ if !ok {
+ return false
+ }
+ fun, ok := callExpr.Fun.(*ast.Ident)
+ if !ok {
+ return false
+ }
+ return fun.Name == "panic"
+}
+
+// findTypeAssertExpr extracts the expression that is being type asserted from a
+// type swtich statement.
+func findTypeAssertExpr(swtch *ast.TypeSwitchStmt) ast.Expr {
+ var expr ast.Expr
+ if assign, ok := swtch.Assign.(*ast.AssignStmt); ok {
+ expr = assign.Rhs[0]
+ } else {
+ expr = swtch.Assign.(*ast.ExprStmt).X
+ }
+ return expr.(*ast.TypeAssertExpr).X
+}
+
+// findDef returns the sum type definition corresponding to the given type. If
+// no such sum type definition exists, then nil is returned.
+func findDef(defs []sumTypeDef, needle types.Type) *sumTypeDef {
+ for i := range defs {
+ def := &defs[i]
+ if types.Identical(needle.Underlying(), def.Ty) {
+ return def
+ }
+ }
+ return nil
+}
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/decl.go b/vendor/github.com/sudarshan-reddy/go-sumtype/decl.go
new file mode 100644
index 00000000..da247a8c
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/decl.go
@@ -0,0 +1,110 @@
+package main
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "log"
+ "os"
+ "path/filepath"
+ "regexp"
+
+ "golang.org/x/tools/go/packages"
+)
+
+// sumTypeDecl is a declaration of a sum type in a Go source file.
+type sumTypeDecl struct {
+ // The package path that contains this decl.
+ Package *packages.Package
+ // The type named by this decl.
+ TypeName string
+ // The file path where this declaration was found.
+ Path string
+ // The line number where this declaration was found.
+ Line int
+}
+
+// Location returns a short string describing where this declaration was found.
+func (d sumTypeDecl) Location() string {
+ return fmt.Sprintf("%s:%d", d.Path, d.Line)
+}
+
+// findSumTypeDecls searches every package given for sum type declarations of
+// the form `go-sumtype:decl ...`.
+func findSumTypeDecls(pkgs []*packages.Package) ([]sumTypeDecl, error) {
+ var decls []sumTypeDecl
+ for _, pkg := range pkgs {
+ for _, filename := range pkg.CompiledGoFiles {
+ if filepath.Base(filename) == "C" {
+ // ignore (fake?) cgo files
+ continue
+ }
+ fileDecls, err := sumTypeDeclSearch(filename)
+ if err != nil {
+ return nil, err
+ }
+ for i := range fileDecls {
+ fileDecls[i].Package = pkg
+ }
+ decls = append(decls, fileDecls...)
+ }
+ }
+ return decls, nil
+}
+
+// sumTypeDeclSearch searches the given file for sum type declarations of the
+// form `go-sumtype:decl ...`.
+func sumTypeDeclSearch(path string) ([]sumTypeDecl, error) {
+ var decls []sumTypeDecl
+
+ f, err := os.Open(path)
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+ lineNum := 0
+ scanner := bufio.NewScanner(f)
+ for scanner.Scan() {
+ lineNum++
+ line := scanner.Bytes()
+ if !isSumTypeDecl(line) {
+ continue
+ }
+ ty := parseSumTypeDecl(line)
+ if len(ty) == 0 {
+ continue
+ }
+ decls = append(decls, sumTypeDecl{
+ TypeName: ty,
+ Path: path,
+ Line: lineNum,
+ })
+ }
+ if err := scanner.Err(); err != nil {
+ // A scanner can puke if it hits a line that is too long.
+ // We assume such files won't contain any future decls and
+ // otherwise move on.
+ log.Printf("scan error reading '%s': %s", path, err)
+ }
+ return decls, nil
+}
+
+var reParseSumTypeDecl = regexp.MustCompile(`^//go-sumtype:decl\s+(\S+)\s*$`)
+
+// parseSumTypeDecl parses the type name out of a sum type decl.
+//
+// If no such decl could be found, then this returns an empty string.
+func parseSumTypeDecl(line []byte) string {
+ caps := reParseSumTypeDecl.FindSubmatch(line)
+ if len(caps) < 2 {
+ return ""
+ }
+ return string(caps[1])
+}
+
+// isSumTypeDecl returns true if and only if this line in a Go source file
+// is a sum type decl.
+func isSumTypeDecl(line []byte) bool {
+ variant1, variant2 := []byte("//go-sumtype:decl "), []byte("//go-sumtype:decl\t")
+ return bytes.HasPrefix(line, variant1) || bytes.HasPrefix(line, variant2)
+}
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/def.go b/vendor/github.com/sudarshan-reddy/go-sumtype/def.go
new file mode 100644
index 00000000..01067f51
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/def.go
@@ -0,0 +1,156 @@
+package main
+
+import (
+ "fmt"
+ "go/ast"
+ "go/types"
+)
+
+// unsealedError corresponds to a declared sum type whose interface is not
+// sealed. A sealed interface requires at least one unexported method.
+type unsealedError struct {
+ Decl sumTypeDecl
+}
+
+func (e unsealedError) Error() string {
+ return fmt.Sprintf(
+ "%s: interface '%s' is not sealed "+
+ "(sealing requires at least one unexported method)",
+ e.Decl.Location(), e.Decl.TypeName)
+}
+
+// notFoundError corresponds to a declared sum type whose type definition
+// could not be found in the same Go package.
+type notFoundError struct {
+ Decl sumTypeDecl
+}
+
+func (e notFoundError) Error() string {
+ return fmt.Sprintf("%s: type '%s' is not defined", e.Decl.Location(), e.Decl.TypeName)
+}
+
+// notInterfaceError corresponds to a declared sum type that does not
+// correspond to an interface.
+type notInterfaceError struct {
+ Decl sumTypeDecl
+}
+
+func (e notInterfaceError) Error() string {
+ return fmt.Sprintf("%s: type '%s' is not an interface", e.Decl.Location(), e.Decl.TypeName)
+}
+
+// sumTypeDef corresponds to the definition of a Go interface that is
+// interpreted as a sum type. Its variants are determined by finding all types
+// that implement said interface in the same package.
+type sumTypeDef struct {
+ Decl sumTypeDecl
+ Ty *types.Interface
+ Variants []types.Object
+}
+
+// findSumTypeDefs attempts to find a Go type definition for each of the given
+// sum type declarations. If no such sum type definition could be found for
+// any of the given declarations, then an error is returned.
+func findSumTypeDefs(decls []sumTypeDecl) ([]sumTypeDef, []error) {
+ var defs []sumTypeDef
+ var errs []error
+ for _, decl := range decls {
+ def, err := newSumTypeDef(decl.Package.Types, decl)
+ if err != nil {
+ errs = append(errs, err)
+ continue
+ }
+ if def == nil {
+ errs = append(errs, notFoundError{decl})
+ continue
+ }
+ defs = append(defs, *def)
+ }
+ return defs, errs
+}
+
+// newSumTypeDef attempts to extract a sum type definition from a single
+// package. If no such type corresponds to the given decl, then this function
+// returns a nil def and a nil error.
+//
+// If the decl corresponds to a type that isn't an interface containing at
+// least one unexported method, then this returns an error.
+func newSumTypeDef(pkg *types.Package, decl sumTypeDecl) (*sumTypeDef, error) {
+ obj := pkg.Scope().Lookup(decl.TypeName)
+ if obj == nil {
+ return nil, nil
+ }
+ iface, ok := obj.Type().Underlying().(*types.Interface)
+ if !ok {
+ return nil, notInterfaceError{decl}
+ }
+ hasUnexported := false
+ for i := 0; i < iface.NumMethods(); i++ {
+ if !iface.Method(i).Exported() {
+ hasUnexported = true
+ break
+ }
+ }
+ if !hasUnexported {
+ return nil, unsealedError{decl}
+ }
+ def := &sumTypeDef{
+ Decl: decl,
+ Ty: iface,
+ }
+ for _, name := range pkg.Scope().Names() {
+ obj, ok := pkg.Scope().Lookup(name).(*types.TypeName)
+ if !ok {
+ continue
+ }
+ ty := obj.Type()
+ if types.Identical(ty.Underlying(), iface) {
+ continue
+ }
+ if types.Implements(ty, iface) || types.Implements(types.NewPointer(ty), iface) {
+ def.Variants = append(def.Variants, obj)
+ }
+ }
+ return def, nil
+}
+
+func (def *sumTypeDef) String() string {
+ return def.Decl.TypeName
+}
+
+// missing returns a list of variants in this sum type that are not in the
+// given list of types.
+func (def *sumTypeDef) missing(tys []types.Type) []types.Object {
+ // TODO(ag): This is O(n^2). Fix that. /shrug
+ var missing []types.Object
+ for _, v := range def.Variants {
+ found := false
+ varty := indirect(v.Type())
+ for _, ty := range tys {
+ ty = indirect(ty)
+ if types.Identical(varty, ty) {
+ found = true
+ }
+ }
+ if !found {
+ missing = append(missing, v)
+ }
+ }
+ return missing
+}
+
+// indirect dereferences through an arbitrary number of pointer types.
+func indirect(ty types.Type) types.Type {
+ if ty, ok := ty.(*types.Pointer); ok {
+ return indirect(ty.Elem())
+ }
+ return ty
+}
+
+func pkgFiles(pkg *ast.Package) []*ast.File {
+ var files []*ast.File
+ for _, file := range pkg.Files {
+ files = append(files, file)
+ }
+ return files
+}
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/doc.go b/vendor/github.com/sudarshan-reddy/go-sumtype/doc.go
new file mode 100644
index 00000000..5941ff75
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/doc.go
@@ -0,0 +1,57 @@
+/*
+go-sumtype takes a list of Go package paths or files and looks for sum type
+declarations in each package/file provided. Exhaustiveness checks are then
+performed for each use of a declared sum type in a type switch statement.
+Namely, go-sumtype will report an error for any type switch statement that
+either lacks a default clause or does not account for all possible variants.
+
+Declarations are provided in comments like so:
+
+ //go-sumtype:decl MySumType
+
+MySumType must satisfy the following:
+
+ 1. It is a type defined in the same package.
+ 2. It is an interface.
+ 3. It is *sealed*. That is, part of its interface definition contains an
+ unexported method.
+
+go-sumtype will produce an error if any of the above is not true.
+
+For valid declarations, go-sumtype will look for all occurrences in which a
+value of type MySumType participates in a type switch statement. In those
+occurrences, it will attempt to detect whether the type switch is exhaustive
+or not. If it's not, go-sumtype will report an error. For example:
+
+ $ cat mysumtype.go
+ package main
+
+ //go-sumtype:decl MySumType
+
+ type MySumType interface {
+ sealed()
+ }
+
+ type VariantA struct{}
+
+ func (a *VariantA) sealed() {}
+
+ type VariantB struct{}
+
+ func (b *VariantB) sealed() {}
+
+ func main() {
+ switch MySumType(nil).(type) {
+ case *VariantA:
+ }
+ }
+ $ go-sumtype mysumtype.go
+ mysumtype.go:18:2: exhaustiveness check failed for sum type 'MySumType': missing cases for VariantB
+
+Adding either a default clause or a clause to handle *VariantB will cause
+exhaustive checks to pass.
+
+As a special case, if the type switch statement contains a default clause
+that always panics, then exhaustiveness checks are still performed.
+*/
+package main
diff --git a/vendor/github.com/sudarshan-reddy/go-sumtype/main.go b/vendor/github.com/sudarshan-reddy/go-sumtype/main.go
new file mode 100644
index 00000000..3fe51bf4
--- /dev/null
+++ b/vendor/github.com/sudarshan-reddy/go-sumtype/main.go
@@ -0,0 +1,74 @@
+package main
+
+import (
+ "log"
+ "os"
+ "strings"
+
+ "golang.org/x/tools/go/loader"
+ "golang.org/x/tools/go/packages"
+)
+
+func main() {
+ log.SetFlags(0)
+ if len(os.Args) < 2 {
+ // TODO: Switch this to use golang.org/x/tools/go/packages.
+ log.Fatalf("Usage: go-sumtype \n%s", loader.FromArgsUsage)
+ }
+ args := os.Args[1:]
+ pkgs, err := tycheckAll(args)
+ if err != nil {
+ log.Fatal(err)
+ }
+ if errs := run(pkgs); len(errs) > 0 {
+ var list []string
+ for _, err := range errs {
+ list = append(list, err.Error())
+ }
+ log.Fatal(strings.Join(list, "\n"))
+ }
+}
+
+func run(pkgs []*packages.Package) []error {
+ var errs []error
+
+ decls, err := findSumTypeDecls(pkgs)
+ if err != nil {
+ return []error{err}
+ }
+
+ defs, defErrs := findSumTypeDefs(decls)
+ errs = append(errs, defErrs...)
+ if len(defs) == 0 {
+ return errs
+ }
+
+ for _, pkg := range pkgs {
+ if pkgErrs := check(pkg, defs); pkgErrs != nil {
+ errs = append(errs, pkgErrs...)
+ }
+ }
+ return errs
+}
+
+func tycheckAll(args []string) ([]*packages.Package, error) {
+ conf := &packages.Config{
+ Mode: packages.LoadSyntax,
+ // Unfortunately, it appears including the test packages in
+ // this lint makes it difficult to do exhaustiveness checking.
+ // Namely, it appears that compiling the test version of a
+ // package introduces distinct types from the normal version
+ // of the package, which will always result in inexhaustive
+ // errors whenever a package both defines a sum type and has
+ // tests. (Specifically, using `package name`. Using `package
+ // name_test` is OK.)
+ //
+ // It's not clear what the best way to fix this is. :-(
+ Tests: false,
+ }
+ pkgs, err := packages.Load(conf, args...)
+ if err != nil {
+ return nil, err
+ }
+ return pkgs, nil
+}
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..5fc672fd
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go
@@ -0,0 +1,113 @@
+// 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 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..8e239086
--- /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 := ©
+ 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
+// newlines. 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..6da0ce48
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/buildutil/tags.go
@@ -0,0 +1,79 @@
+// 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 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 ""
+}
+
+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..d01fb04a
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go
@@ -0,0 +1,222 @@
+// 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 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.
+
+package cgo
+
+import (
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "io/ioutil"
+ "log"
+ "os"
+ "path/filepath"
+ "regexp"
+ "strings"
+
+ exec "golang.org/x/sys/execabs"
+)
+
+// 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.Env = append(os.Environ(), "PWD="+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..7d94bbc1
--- /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"
+ exec "golang.org/x/sys/execabs"
+ "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..c5aa31c1
--- /dev/null
+++ b/vendor/golang.org/x/tools/go/loader/doc.go
@@ -0,0 +1,204 @@
+// 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.
+//
+// Deprecated: This is an older API and does not have support
+// for modules. Use golang.org/x/tools/go/packages instead.
+//
+// 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.
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..508a1fd0
--- /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 = `
+ 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://golang.org/issue/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 {
+ // Normalize cycle: start from alphabetically largest node.
+ pos, start := -1, ""
+ for i, s := range cycle {
+ if pos < 0 || s > start {
+ pos, start = i, s
+ }
+ }
+ cycle = append(cycle, cycle[:pos]...)[pos:] // rotate cycle to start from largest
+ cycle = append(cycle, cycle[0]) // add start node to end to show cycliness
+ 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 ยง9.7)
+ // 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) {
+ 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 importPath := range imports {
+ deps[importPath] = true
+ }
+ imp.graphMu.Unlock()
+ }
+
+ var pending []*importInfo
+ for importPath := range imports {
+ if fromPath != "" {
+ if cycle := imp.findPath(importPath, fromPath); cycle != nil {
+ // Cycle-forming import: we must not check it
+ // since it would deadlock.
+ if trace {
+ fmt.Fprintf(os.Stderr, "import cycle: %q\n", cycle)
+ }
+ continue
+ }
+ }
+ 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))
+ }
+
+ for _, ii := range pending {
+ 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()
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 648e7327..0fae1965 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -332,6 +332,9 @@ github.com/russross/blackfriday/v2
## explicit; go 1.13
github.com/stretchr/testify/assert
github.com/stretchr/testify/require
+# github.com/sudarshan-reddy/go-sumtype v0.0.0-20210827105221-82eca7e5abb1
+## explicit; go 1.16
+github.com/sudarshan-reddy/go-sumtype
# github.com/urfave/cli/v2 v2.3.0 => github.com/ipostelnik/cli/v2 v2.3.1-0.20210324024421-b6ea8234fe3d
## explicit; go 1.11
github.com/urfave/cli/v2
@@ -419,9 +422,12 @@ golang.org/x/text/unicode/norm
## explicit; go 1.17
golang.org/x/tools/go/ast/astutil
golang.org/x/tools/go/ast/inspector
+golang.org/x/tools/go/buildutil
golang.org/x/tools/go/gcexportdata
+golang.org/x/tools/go/internal/cgo
golang.org/x/tools/go/internal/gcimporter
golang.org/x/tools/go/internal/packagesdriver
+golang.org/x/tools/go/loader
golang.org/x/tools/go/packages
golang.org/x/tools/imports
golang.org/x/tools/internal/event