blob: 8afa9d5240408a6d36df874ca9d5a8fe43bb708f [file] [log] [blame]
// Copyright 2011 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 build
import (
"bytes"
"errors"
"fmt"
"go/ast"
"go/build/constraint"
"go/doc"
"go/token"
"internal/buildcfg"
exec "internal/execabs"
"internal/goroot"
"internal/goversion"
"io"
"io/fs"
"io/ioutil"
"os"
pathpkg "path"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"unicode"
"unicode/utf8"
)
// A Context specifies the supporting context for a build.
type Context struct {
GOARCH string // target architecture
GOOS string // target operating system
GOROOT string // Go root
GOPATH string // Go path
// Dir is the caller's working directory, or the empty string to use
// the current directory of the running process. In module mode, this is used
// to locate the main module.
//
// If Dir is non-empty, directories passed to Import and ImportDir must
// be absolute.
Dir string
CgoEnabled bool // whether cgo files are included
UseAllFiles bool // use files regardless of +build lines, file names
Compiler string // compiler to assume when computing target paths
// The build, tool, and release tags specify build constraints
// that should be considered satisfied when processing +build lines.
// Clients creating a new context may customize BuildTags, which
// defaults to empty, but it is usually an error to customize ToolTags or ReleaseTags.
// ToolTags defaults to build tags appropriate to the current Go toolchain configuration.
// ReleaseTags defaults to the list of Go releases the current release is compatible with.
// BuildTags is not set for the Default build Context.
// In addition to the BuildTags, ToolTags, and ReleaseTags, build constraints
// consider the values of GOARCH and GOOS as satisfied tags.
// The last element in ReleaseTags is assumed to be the current release.
BuildTags []string
ToolTags []string
ReleaseTags []string
// The install suffix specifies a suffix to use in the name of the installation
// directory. By default it is empty, but custom builds that need to keep
// their outputs separate can set InstallSuffix to do so. For example, when
// using the race detector, the go command uses InstallSuffix = "race", so
// that on a Linux/386 system, packages are written to a directory named
// "linux_386_race" instead of the usual "linux_386".
InstallSuffix string
// By default, Import uses the operating system's file system calls
// to read directories and files. To read from other sources,
// callers can set the following functions. They all have default
// behaviors that use the local file system, so clients need only set
// the functions whose behaviors they wish to change.
// JoinPath joins the sequence of path fragments into a single path.
// If JoinPath is nil, Import uses filepath.Join.
JoinPath func(elem ...string) string
// SplitPathList splits the path list into a slice of individual paths.
// If SplitPathList is nil, Import uses filepath.SplitList.
SplitPathList func(list string) []string
// IsAbsPath reports whether path is an absolute path.
// If IsAbsPath is nil, Import uses filepath.IsAbs.
IsAbsPath func(path string) bool
// IsDir reports whether the path names a directory.
// If IsDir is nil, Import calls os.Stat and uses the result's IsDir method.
IsDir func(path string) bool
// HasSubdir reports whether dir is lexically a subdirectory of
// root, perhaps multiple levels below. It does not try to check
// whether dir exists.
// If so, HasSubdir sets rel to a slash-separated path that
// can be joined to root to produce a path equivalent to dir.
// If HasSubdir is nil, Import uses an implementation built on
// filepath.EvalSymlinks.
HasSubdir func(root, dir string) (rel string, ok bool)
// ReadDir returns a slice of fs.FileInfo, sorted by Name,
// describing the content of the named directory.
// If ReadDir is nil, Import uses ioutil.ReadDir.
ReadDir func(dir string) ([]fs.FileInfo, error)
// OpenFile opens a file (not a directory) for reading.
// If OpenFile is nil, Import uses os.Open.
OpenFile func(path string) (io.ReadCloser, error)
}
// joinPath calls ctxt.JoinPath (if not nil) or else filepath.Join.
func (ctxt *Context) joinPath(elem ...string) string {
if f := ctxt.JoinPath; f != nil {
return f(elem...)
}
return filepath.Join(elem...)
}
// splitPathList calls ctxt.SplitPathList (if not nil) or else filepath.SplitList.
func (ctxt *Context) splitPathList(s string) []string {
if f := ctxt.SplitPathList; f != nil {
return f(s)
}
return filepath.SplitList(s)
}
// isAbsPath calls ctxt.IsAbsPath (if not nil) or else filepath.IsAbs.
func (ctxt *Context) isAbsPath(path string) bool {
if f := ctxt.IsAbsPath; f != nil {
return f(path)
}
return filepath.IsAbs(path)
}
// isDir calls ctxt.IsDir (if not nil) or else uses os.Stat.
func (ctxt *Context) isDir(path string) bool {
if f := ctxt.IsDir; f != nil {
return f(path)
}
fi, err := os.Stat(path)
return err == nil && fi.IsDir()
}
// hasSubdir calls ctxt.HasSubdir (if not nil) or else uses
// the local file system to answer the question.
func (ctxt *Context) hasSubdir(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)
}
// hasSubdir reports if dir is within root by performing lexical analysis only.
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
}
// readDir calls ctxt.ReadDir (if not nil) or else ioutil.ReadDir.
func (ctxt *Context) readDir(path string) ([]fs.FileInfo, error) {
if f := ctxt.ReadDir; f != nil {
return f(path)
}
// TODO: use os.ReadDir
return ioutil.ReadDir(path)
}
// openFile calls ctxt.OpenFile (if not nil) or else os.Open.
func (ctxt *Context) openFile(path string) (io.ReadCloser, error) {
if fn := ctxt.OpenFile; fn != nil {
return fn(path)
}
f, err := os.Open(path)
if err != nil {
return nil, err // nil interface
}
return f, nil
}
// isFile determines whether path is a file by trying to open it.
// It reuses openFile instead of adding another function to the
// list in Context.
func (ctxt *Context) isFile(path string) bool {
f, err := ctxt.openFile(path)
if err != nil {
return false
}
f.Close()
return true
}
// gopath returns the list of Go path directories.
func (ctxt *Context) gopath() []string {
var all []string
for _, p := range ctxt.splitPathList(ctxt.GOPATH) {
if p == "" || p == ctxt.GOROOT {
// Empty paths are uninteresting.
// If the path is the GOROOT, ignore it.
// People sometimes set GOPATH=$GOROOT.
// Do not get confused by this common mistake.
continue
}
if strings.HasPrefix(p, "~") {
// Path segments starting with ~ on Unix are almost always
// users who have incorrectly quoted ~ while setting GOPATH,
// preventing it from expanding to $HOME.
// The situation is made more confusing by the fact that
// bash allows quoted ~ in $PATH (most shells do not).
// Do not get confused by this, and do not try to use the path.
// It does not exist, and printing errors about it confuses
// those users even more, because they think "sure ~ exists!".
// The go command diagnoses this situation and prints a
// useful error.
// On Windows, ~ is used in short names, such as c:\progra~1
// for c:\program files.
continue
}
all = append(all, p)
}
return all
}
// SrcDirs returns a list of package source root directories.
// It draws from the current Go root and Go path but omits directories
// that do not exist.
func (ctxt *Context) SrcDirs() []string {
var all []string
if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
dir := ctxt.joinPath(ctxt.GOROOT, "src")
if ctxt.isDir(dir) {
all = append(all, dir)
}
}
for _, p := range ctxt.gopath() {
dir := ctxt.joinPath(p, "src")
if ctxt.isDir(dir) {
all = append(all, dir)
}
}
return all
}
// Default is the default Context for builds.
// It uses the GOARCH, GOOS, GOROOT, and GOPATH environment variables
// if set, or else the compiled code's GOARCH, GOOS, and GOROOT.
var Default Context = defaultContext()
func defaultGOPATH() string {
env := "HOME"
if runtime.GOOS == "windows" {
env = "USERPROFILE"
} else if runtime.GOOS == "plan9" {
env = "home"
}
if home := os.Getenv(env); home != "" {
def := filepath.Join(home, "go")
if filepath.Clean(def) == filepath.Clean(runtime.GOROOT()) {
// Don't set the default GOPATH to GOROOT,
// as that will trigger warnings from the go tool.
return ""
}
return def
}
return ""
}
var defaultToolTags, defaultReleaseTags []string
func defaultContext() Context {
var c Context
c.GOARCH = buildcfg.GOARCH
c.GOOS = buildcfg.GOOS
c.GOROOT = pathpkg.Clean(runtime.GOROOT())
c.GOPATH = envOr("GOPATH", defaultGOPATH())
c.Compiler = runtime.Compiler
// For each experiment that has been enabled in the toolchain, define a
// build tag with the same name but prefixed by "goexperiment." which can be
// used for compiling alternative files for the experiment. This allows
// changes for the experiment, like extra struct fields in the runtime,
// without affecting the base non-experiment code at all.
for _, exp := range buildcfg.EnabledExperiments() {
c.ToolTags = append(c.ToolTags, "goexperiment."+exp)
}
defaultToolTags = append([]string{}, c.ToolTags...) // our own private copy
// Each major Go release in the Go 1.x series adds a new
// "go1.x" release tag. That is, the go1.x tag is present in
// all releases >= Go 1.x. Code that requires Go 1.x or later
// should say "+build go1.x", and code that should only be
// built before Go 1.x (perhaps it is the stub to use in that
// case) should say "+build !go1.x".
// The last element in ReleaseTags is the current release.
for i := 1; i <= goversion.Version; i++ {
c.ReleaseTags = append(c.ReleaseTags, "go1."+strconv.Itoa(i))
}
defaultReleaseTags = append([]string{}, c.ReleaseTags...) // our own private copy
env := os.Getenv("CGO_ENABLED")
if env == "" {
env = defaultCGO_ENABLED
}
switch env {
case "1":
c.CgoEnabled = true
case "0":
c.CgoEnabled = false
default:
// cgo must be explicitly enabled for cross compilation builds
if runtime.GOARCH == c.GOARCH && runtime.GOOS == c.GOOS {
c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
break
}
c.CgoEnabled = false
}
return c
}
func envOr(name, def string) string {
s := os.Getenv(name)
if s == "" {
return def
}
return s
}
// An ImportMode controls the behavior of the Import method.
type ImportMode uint
const (
// If FindOnly is set, Import stops after locating the directory
// that should contain the sources for a package. It does not
// read any files in the directory.
FindOnly ImportMode = 1 << iota
// If AllowBinary is set, Import can be satisfied by a compiled
// package object without corresponding sources.
//
// Deprecated:
// The supported way to create a compiled-only package is to
// write source code containing a //go:binary-only-package comment at
// the top of the file. Such a package will be recognized
// regardless of this flag setting (because it has source code)
// and will have BinaryOnly set to true in the returned Package.
AllowBinary
// If ImportComment is set, parse import comments on package statements.
// Import returns an error if it finds a comment it cannot understand
// or finds conflicting comments in multiple source files.
// See golang.org/s/go14customimport for more information.
ImportComment
// By default, Import searches vendor directories
// that apply in the given source directory before searching
// the GOROOT and GOPATH roots.
// If an Import finds and returns a package using a vendor
// directory, the resulting ImportPath is the complete path
// to the package, including the path elements leading up
// to and including "vendor".
// For example, if Import("y", "x/subdir", 0) finds
// "x/vendor/y", the returned package's ImportPath is "x/vendor/y",
// not plain "y".
// See golang.org/s/go15vendor for more information.
//
// Setting IgnoreVendor ignores vendor directories.
//
// In contrast to the package's ImportPath,
// the returned package's Imports, TestImports, and XTestImports
// are always the exact import paths from the source files:
// Import makes no attempt to resolve or check those paths.
IgnoreVendor
)
// A Package describes the Go package found in a directory.
type Package struct {
Dir string // directory containing package sources
Name string // package name
ImportComment string // path in import comment on package statement
Doc string // documentation synopsis
ImportPath string // import path of package ("" if unknown)
Root string // root of Go tree where this package lives
SrcRoot string // package source root directory ("" if unknown)
PkgRoot string // package install root directory ("" if unknown)
PkgTargetRoot string // architecture dependent install root directory ("" if unknown)
BinDir string // command install directory ("" if unknown)
Goroot bool // package found in Go root
PkgObj string // installed .a file
AllTags []string // tags that can influence file selection in this directory
ConflictDir string // this directory shadows Dir in $GOPATH
BinaryOnly bool // cannot be rebuilt from source (has //go:binary-only-package comment)
// Source files
GoFiles []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
CgoFiles []string // .go source files that import "C"
IgnoredGoFiles []string // .go source files ignored for this build (including ignored _test.go files)
InvalidGoFiles []string // .go source files with detected problems (parse error, wrong package name, and so on)
IgnoredOtherFiles []string // non-.go source files ignored for this build
CFiles []string // .c source files
CXXFiles []string // .cc, .cpp and .cxx source files
MFiles []string // .m (Objective-C) source files
HFiles []string // .h, .hh, .hpp and .hxx source files
FFiles []string // .f, .F, .for and .f90 Fortran source files
SFiles []string // .s source files
SwigFiles []string // .swig files
SwigCXXFiles []string // .swigcxx files
SysoFiles []string // .syso system object files to add to archive
// Cgo directives
CgoCFLAGS []string // Cgo CFLAGS directives
CgoCPPFLAGS []string // Cgo CPPFLAGS directives
CgoCXXFLAGS []string // Cgo CXXFLAGS directives
CgoFFLAGS []string // Cgo FFLAGS directives
CgoLDFLAGS []string // Cgo LDFLAGS directives
CgoPkgConfig []string // Cgo pkg-config directives
// Test information
TestGoFiles []string // _test.go files in package
XTestGoFiles []string // _test.go files outside package
// Dependency information
Imports []string // import paths from GoFiles, CgoFiles
ImportPos map[string][]token.Position // line information for Imports
TestImports []string // import paths from TestGoFiles
TestImportPos map[string][]token.Position // line information for TestImports
XTestImports []string // import paths from XTestGoFiles
XTestImportPos map[string][]token.Position // line information for XTestImports
// //go:embed patterns found in Go source files
// For example, if a source file says
// //go:embed a* b.c
// then the list will contain those two strings as separate entries.
// (See package embed for more details about //go:embed.)
EmbedPatterns []string // patterns from GoFiles, CgoFiles
EmbedPatternPos map[string][]token.Position // line information for EmbedPatterns
TestEmbedPatterns []string // patterns from TestGoFiles
TestEmbedPatternPos map[string][]token.Position // line information for TestEmbedPatterns
XTestEmbedPatterns []string // patterns from XTestGoFiles
XTestEmbedPatternPos map[string][]token.Position // line information for XTestEmbedPatternPos
}
// IsCommand reports whether the package is considered a
// command to be installed (not just a library).
// Packages named "main" are treated as commands.
func (p *Package) IsCommand() bool {
return p.Name == "main"
}
// ImportDir is like Import but processes the Go package found in
// the named directory.
func (ctxt *Context) ImportDir(dir string, mode ImportMode) (*Package, error) {
return ctxt.Import(".", dir, mode)
}
// NoGoError is the error used by Import to describe a directory
// containing no buildable Go source files. (It may still contain
// test files, files hidden by build tags, and so on.)
type NoGoError struct {
Dir string
}
func (e *NoGoError) Error() string {
return "no buildable Go source files in " + e.Dir
}
// MultiplePackageError describes a directory containing
// multiple buildable Go source files for multiple packages.
type MultiplePackageError struct {
Dir string // directory containing files
Packages []string // package names found
Files []string // corresponding files: Files[i] declares package Packages[i]
}
func (e *MultiplePackageError) Error() string {
// Error string limited to two entries for compatibility.
return fmt.Sprintf("found packages %s (%s) and %s (%s) in %s", e.Packages[0], e.Files[0], e.Packages[1], e.Files[1], e.Dir)
}
func nameExt(name string) string {
i := strings.LastIndex(name, ".")
if i < 0 {
return ""
}
return name[i:]
}
// Import returns details about the Go package named by the import path,
// interpreting local import paths relative to the srcDir directory.
// If the path is a local import path naming a package that can be imported
// using a standard import path, the returned package will set p.ImportPath
// to that path.
//
// In the directory containing the package, .go, .c, .h, and .s files are
// considered part of the package except for:
//
// - .go files in package documentation
// - files starting with _ or . (likely editor temporary files)
// - files with build constraints not satisfied by the context
//
// If an error occurs, Import returns a non-nil error and a non-nil
// *Package containing partial information.
//
func (ctxt *Context) Import(path string, srcDir string, mode ImportMode) (*Package, error) {
p := &Package{
ImportPath: path,
}
if path == "" {
return p, fmt.Errorf("import %q: invalid import path", path)
}
var pkgtargetroot string
var pkga string
var pkgerr error
suffix := ""
if ctxt.InstallSuffix != "" {
suffix = "_" + ctxt.InstallSuffix
}
switch ctxt.Compiler {
case "gccgo":
pkgtargetroot = "pkg/gccgo_" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
case "gc":
pkgtargetroot = "pkg/" + ctxt.GOOS + "_" + ctxt.GOARCH + suffix
default:
// Save error for end of function.
pkgerr = fmt.Errorf("import %q: unknown compiler %q", path, ctxt.Compiler)
}
setPkga := func() {
switch ctxt.Compiler {
case "gccgo":
dir, elem := pathpkg.Split(p.ImportPath)
pkga = pkgtargetroot + "/" + dir + "lib" + elem + ".a"
case "gc":
pkga = pkgtargetroot + "/" + p.ImportPath + ".a"
}
}
setPkga()
binaryOnly := false
if IsLocalImport(path) {
pkga = "" // local imports have no installed path
if srcDir == "" {
return p, fmt.Errorf("import %q: import relative to unknown directory", path)
}
if !ctxt.isAbsPath(path) {
p.Dir = ctxt.joinPath(srcDir, path)
}
// p.Dir directory may or may not exist. Gather partial information first, check if it exists later.
// Determine canonical import path, if any.
// Exclude results where the import path would include /testdata/.
inTestdata := func(sub string) bool {
return strings.Contains(sub, "/testdata/") || strings.HasSuffix(sub, "/testdata") || strings.HasPrefix(sub, "testdata/") || sub == "testdata"
}
if ctxt.GOROOT != "" {
root := ctxt.joinPath(ctxt.GOROOT, "src")
if sub, ok := ctxt.hasSubdir(root, p.Dir); ok && !inTestdata(sub) {
p.Goroot = true
p.ImportPath = sub
p.Root = ctxt.GOROOT
setPkga() // p.ImportPath changed
goto Found
}
}
all := ctxt.gopath()
for i, root := range all {
rootsrc := ctxt.joinPath(root, "src")
if sub, ok := ctxt.hasSubdir(rootsrc, p.Dir); ok && !inTestdata(sub) {
// We found a potential import path for dir,
// but check that using it wouldn't find something
// else first.
if ctxt.GOROOT != "" && ctxt.Compiler != "gccgo" {
if dir := ctxt.joinPath(ctxt.GOROOT, "src", sub); ctxt.isDir(dir) {
p.ConflictDir = dir
goto Found
}
}
for _, earlyRoot := range all[:i] {
if dir := ctxt.joinPath(earlyRoot, "src", sub); ctxt.isDir(dir) {
p.ConflictDir = dir
goto Found
}
}
// sub would not name some other directory instead of this one.
// Record it.
p.ImportPath = sub
p.Root = root
setPkga() // p.ImportPath changed
goto Found
}
}
// It's okay that we didn't find a root containing dir.
// Keep going with the information we have.
} else {
if strings.HasPrefix(path, "/") {
return p, fmt.Errorf("import %q: cannot import absolute path", path)
}
if err := ctxt.importGo(p, path, srcDir, mode); err == nil {
goto Found
} else if err != errNoModules {
return p, err
}
gopath := ctxt.gopath() // needed twice below; avoid computing many times
// tried records the location of unsuccessful package lookups
var tried struct {
vendor []string
goroot string
gopath []string
}
// Vendor directories get first chance to satisfy import.
if mode&IgnoreVendor == 0 && srcDir != "" {
searchVendor := func(root string, isGoroot bool) bool {
sub, ok := ctxt.hasSubdir(root, srcDir)
if !ok || !strings.HasPrefix(sub, "src/") || strings.Contains(sub, "/testdata/") {
return false
}
for {
vendor := ctxt.joinPath(root, sub, "vendor")
if ctxt.isDir(vendor) {
dir := ctxt.joinPath(vendor, path)
if ctxt.isDir(dir) && hasGoFiles(ctxt, dir) {
p.Dir = dir
p.ImportPath = strings.TrimPrefix(pathpkg.Join(sub, "vendor", path), "src/")
p.Goroot = isGoroot
p.Root = root
setPkga() // p.ImportPath changed
return true
}
tried.vendor = append(tried.vendor, dir)
}
i := strings.LastIndex(sub, "/")
if i < 0 {
break
}
sub = sub[:i]
}
return false
}
if ctxt.Compiler != "gccgo" && searchVendor(ctxt.GOROOT, true) {
goto Found
}
for _, root := range gopath {
if searchVendor(root, false) {
goto Found
}
}
}
// Determine directory from import path.
if ctxt.GOROOT != "" {
// If the package path starts with "vendor/", only search GOROOT before
// GOPATH if the importer is also within GOROOT. That way, if the user has
// vendored in a package that is subsequently included in the standard
// distribution, they'll continue to pick up their own vendored copy.
gorootFirst := srcDir == "" || !strings.HasPrefix(path, "vendor/")
if !gorootFirst {
_, gorootFirst = ctxt.hasSubdir(ctxt.GOROOT, srcDir)
}
if gorootFirst {
dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
if ctxt.Compiler != "gccgo" {
isDir := ctxt.isDir(dir)
binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
if isDir || binaryOnly {
p.Dir = dir
p.Goroot = true
p.Root = ctxt.GOROOT
goto Found
}
}
tried.goroot = dir
}
}
if ctxt.Compiler == "gccgo" && goroot.IsStandardPackage(ctxt.GOROOT, ctxt.Compiler, path) {
p.Dir = ctxt.joinPath(ctxt.GOROOT, "src", path)
p.Goroot = true
p.Root = ctxt.GOROOT
goto Found
}
for _, root := range gopath {
dir := ctxt.joinPath(root, "src", path)
isDir := ctxt.isDir(dir)
binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(root, pkga))
if isDir || binaryOnly {
p.Dir = dir
p.Root = root
goto Found
}
tried.gopath = append(tried.gopath, dir)
}
// If we tried GOPATH first due to a "vendor/" prefix, fall back to GOPATH.
// That way, the user can still get useful results from 'go list' for
// standard-vendored paths passed on the command line.
if ctxt.GOROOT != "" && tried.goroot == "" {
dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
if ctxt.Compiler != "gccgo" {
isDir := ctxt.isDir(dir)
binaryOnly = !isDir && mode&AllowBinary != 0 && pkga != "" && ctxt.isFile(ctxt.joinPath(ctxt.GOROOT, pkga))
if isDir || binaryOnly {
p.Dir = dir
p.Goroot = true
p.Root = ctxt.GOROOT
goto Found
}
}
tried.goroot = dir
}
// package was not found
var paths []string
format := "\t%s (vendor tree)"
for _, dir := range tried.vendor {
paths = append(paths, fmt.Sprintf(format, dir))
format = "\t%s"
}
if tried.goroot != "" {
paths = append(paths, fmt.Sprintf("\t%s (from $GOROOT)", tried.goroot))
} else {
paths = append(paths, "\t($GOROOT not set)")
}
format = "\t%s (from $GOPATH)"
for _, dir := range tried.gopath {
paths = append(paths, fmt.Sprintf(format, dir))
format = "\t%s"
}
if len(tried.gopath) == 0 {
paths = append(paths, "\t($GOPATH not set. For more details see: 'go help gopath')")
}
return p, fmt.Errorf("cannot find package %q in any of:\n%s", path, strings.Join(paths, "\n"))
}
Found:
if p.Root != "" {
p.SrcRoot = ctxt.joinPath(p.Root, "src")
p.PkgRoot = ctxt.joinPath(p.Root, "pkg")
p.BinDir = ctxt.joinPath(p.Root, "bin")
if pkga != "" {
p.PkgTargetRoot = ctxt.joinPath(p.Root, pkgtargetroot)
p.PkgObj = ctxt.joinPath(p.Root, pkga)
}
}
// If it's a local import path, by the time we get here, we still haven't checked
// that p.Dir directory exists. This is the right time to do that check.
// We can't do it earlier, because we want to gather partial information for the
// non-nil *Package returned when an error occurs.
// We need to do this before we return early on FindOnly flag.
if IsLocalImport(path) && !ctxt.isDir(p.Dir) {
if ctxt.Compiler == "gccgo" && p.Goroot {
// gccgo has no sources for GOROOT packages.
return p, nil
}
// package was not found
return p, fmt.Errorf("cannot find package %q in:\n\t%s", path, p.Dir)
}
if mode&FindOnly != 0 {
return p, pkgerr
}
if binaryOnly && (mode&AllowBinary) != 0 {
return p, pkgerr
}
if ctxt.Compiler == "gccgo" && p.Goroot {
// gccgo has no sources for GOROOT packages.
return p, nil
}
dirs, err := ctxt.readDir(p.Dir)
if err != nil {
return p, err
}
var badGoError error
badFiles := make(map[string]bool)
badFile := func(name string, err error) {
if badGoError == nil {
badGoError = err
}
if !badFiles[name] {
p.InvalidGoFiles = append(p.InvalidGoFiles, name)
badFiles[name] = true
}
}
var Sfiles []string // files with ".S"(capital S)/.sx(capital s equivalent for case insensitive filesystems)
var firstFile, firstCommentFile string
embedPos := make(map[string][]token.Position)
testEmbedPos := make(map[string][]token.Position)
xTestEmbedPos := make(map[string][]token.Position)
importPos := make(map[string][]token.Position)
testImportPos := make(map[string][]token.Position)
xTestImportPos := make(map[string][]token.Position)
allTags := make(map[string]bool)
fset := token.NewFileSet()
for _, d := range dirs {
if d.IsDir() {
continue
}
if d.Mode()&fs.ModeSymlink != 0 {
if ctxt.isDir(ctxt.joinPath(p.Dir, d.Name())) {
// Symlinks to directories are not source files.
continue
}
}
name := d.Name()
ext := nameExt(name)
info, err := ctxt.matchFile(p.Dir, name, allTags, &p.BinaryOnly, fset)
if err != nil {
badFile(name, err)
continue
}
if info == nil {
if strings.HasPrefix(name, "_") || strings.HasPrefix(name, ".") {
// not due to build constraints - don't report
} else if ext == ".go" {
p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
} else if fileListForExt(p, ext) != nil {
p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, name)
}
continue
}
data, filename := info.header, info.name
// Going to save the file. For non-Go files, can stop here.
switch ext {
case ".go":
// keep going
case ".S", ".sx":
// special case for cgo, handled at end
Sfiles = append(Sfiles, name)
continue
default:
if list := fileListForExt(p, ext); list != nil {
*list = append(*list, name)
}
continue
}
if info.parseErr != nil {
badFile(name, info.parseErr)
// Fall through: we might still have a partial AST in info.parsed,
// and we want to list files with parse errors anyway.
}
var pkg string
if info.parsed != nil {
pkg = info.parsed.Name.Name
if pkg == "documentation" {
p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
continue
}
}
isTest := strings.HasSuffix(name, "_test.go")
isXTest := false
if isTest && strings.HasSuffix(pkg, "_test") {
isXTest = true
pkg = pkg[:len(pkg)-len("_test")]
}
if p.Name == "" {
p.Name = pkg
firstFile = name
} else if pkg != p.Name {
// TODO(#45999): The choice of p.Name is arbitrary based on file iteration
// order. Instead of resolving p.Name arbitrarily, we should clear out the
// existing name and mark the existing files as also invalid.
badFile(name, &MultiplePackageError{
Dir: p.Dir,
Packages: []string{p.Name, pkg},
Files: []string{firstFile, name},
})
}
// Grab the first package comment as docs, provided it is not from a test file.
if info.parsed != nil && info.parsed.Doc != nil && p.Doc == "" && !isTest && !isXTest {
p.Doc = doc.Synopsis(info.parsed.Doc.Text())
}
if mode&ImportComment != 0 {
qcom, line := findImportComment(data)
if line != 0 {
com, err := strconv.Unquote(qcom)
if err != nil {
badFile(name, fmt.Errorf("%s:%d: cannot parse import comment", filename, line))
} else if p.ImportComment == "" {
p.ImportComment = com
firstCommentFile = name
} else if p.ImportComment != com {
badFile(name, fmt.Errorf("found import comments %q (%s) and %q (%s) in %s", p.ImportComment, firstCommentFile, com, name, p.Dir))
}
}
}
// Record imports and information about cgo.
isCgo := false
for _, imp := range info.imports {
if imp.path == "C" {
if isTest {
badFile(name, fmt.Errorf("use of cgo in test %s not supported", filename))
continue
}
isCgo = true
if imp.doc != nil {
if err := ctxt.saveCgo(filename, p, imp.doc); err != nil {
badFile(name, err)
}
}
}
}
var fileList *[]string
var importMap, embedMap map[string][]token.Position
switch {
case isCgo:
allTags["cgo"] = true
if ctxt.CgoEnabled {
fileList = &p.CgoFiles
importMap = importPos
embedMap = embedPos
} else {
// Ignore imports and embeds from cgo files if cgo is disabled.
fileList = &p.IgnoredGoFiles
}
case isXTest:
fileList = &p.XTestGoFiles
importMap = xTestImportPos
embedMap = xTestEmbedPos
case isTest:
fileList = &p.TestGoFiles
importMap = testImportPos
embedMap = testEmbedPos
default:
fileList = &p.GoFiles
importMap = importPos
embedMap = embedPos
}
*fileList = append(*fileList, name)
if importMap != nil {
for _, imp := range info.imports {
importMap[imp.path] = append(importMap[imp.path], fset.Position(imp.pos))
}
}
if embedMap != nil {
for _, emb := range info.embeds {
embedMap[emb.pattern] = append(embedMap[emb.pattern], emb.pos)
}
}
}
for tag := range allTags {
p.AllTags = append(p.AllTags, tag)
}
sort.Strings(p.AllTags)
p.EmbedPatterns, p.EmbedPatternPos = cleanDecls(embedPos)
p.TestEmbedPatterns, p.TestEmbedPatternPos = cleanDecls(testEmbedPos)
p.XTestEmbedPatterns, p.XTestEmbedPatternPos = cleanDecls(xTestEmbedPos)
p.Imports, p.ImportPos = cleanDecls(importPos)
p.TestImports, p.TestImportPos = cleanDecls(testImportPos)
p.XTestImports, p.XTestImportPos = cleanDecls(xTestImportPos)
// add the .S/.sx files only if we are using cgo
// (which means gcc will compile them).
// The standard assemblers expect .s files.
if len(p.CgoFiles) > 0 {
p.SFiles = append(p.SFiles, Sfiles...)
sort.Strings(p.SFiles)
} else {
p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, Sfiles...)
sort.Strings(p.IgnoredOtherFiles)
}
if badGoError != nil {
return p, badGoError
}
if len(p.GoFiles)+len(p.CgoFiles)+len(p.TestGoFiles)+len(p.XTestGoFiles) == 0 {
return p, &NoGoError{p.Dir}
}
return p, pkgerr
}
func fileListForExt(p *Package, ext string) *[]string {
switch ext {
case ".c":
return &p.CFiles
case ".cc", ".cpp", ".cxx":
return &p.CXXFiles
case ".m":
return &p.MFiles
case ".h", ".hh", ".hpp", ".hxx":
return &p.HFiles
case ".f", ".F", ".for", ".f90":
return &p.FFiles
case ".s", ".S", ".sx":
return &p.SFiles
case ".swig":
return &p.SwigFiles
case ".swigcxx":
return &p.SwigCXXFiles
case ".syso":
return &p.SysoFiles
}
return nil
}
func uniq(list []string) []string {
if list == nil {
return nil
}
out := make([]string, len(list))
copy(out, list)
sort.Strings(out)
uniq := out[:0]
for _, x := range out {
if len(uniq) == 0 || uniq[len(uniq)-1] != x {
uniq = append(uniq, x)
}
}
return uniq
}
var errNoModules = errors.New("not using modules")
// importGo checks whether it can use the go command to find the directory for path.
// If using the go command is not appropriate, importGo returns errNoModules.
// Otherwise, importGo tries using the go command and reports whether that succeeded.
// Using the go command lets build.Import and build.Context.Import find code
// in Go modules. In the long term we want tools to use go/packages (currently golang.org/x/tools/go/packages),
// which will also use the go command.
// Invoking the go command here is not very efficient in that it computes information
// about the requested package and all dependencies and then only reports about the requested package.
// Then we reinvoke it for every dependency. But this is still better than not working at all.
// See golang.org/issue/26504.
func (ctxt *Context) importGo(p *Package, path, srcDir string, mode ImportMode) error {
// To invoke the go command,
// we must not being doing special things like AllowBinary or IgnoreVendor,
// and all the file system callbacks must be nil (we're meant to use the local file system).
if mode&AllowBinary != 0 || mode&IgnoreVendor != 0 ||
ctxt.JoinPath != nil || ctxt.SplitPathList != nil || ctxt.IsAbsPath != nil || ctxt.IsDir != nil || ctxt.HasSubdir != nil || ctxt.ReadDir != nil || ctxt.OpenFile != nil || !equal(ctxt.ToolTags, defaultToolTags) || !equal(ctxt.ReleaseTags, defaultReleaseTags) {
return errNoModules
}
// Predict whether module aware mode is enabled by checking the value of
// GO111MODULE and looking for a go.mod file in the source directory or
// one of its parents. Running 'go env GOMOD' in the source directory would
// give a canonical answer, but we'd prefer not to execute another command.
go111Module := os.Getenv("GO111MODULE")
switch go111Module {
case "off":
return errNoModules
default: // "", "on", "auto", anything else
// Maybe use modules.
}
if srcDir != "" {
var absSrcDir string
if filepath.IsAbs(srcDir) {
absSrcDir = srcDir
} else if ctxt.Dir != "" {
return fmt.Errorf("go/build: Dir is non-empty, so relative srcDir is not allowed: %v", srcDir)
} else {
// Find the absolute source directory. hasSubdir does not handle
// relative paths (and can't because the callbacks don't support this).
var err error
absSrcDir, err = filepath.Abs(srcDir)
if err != nil {
return errNoModules
}
}
// If the source directory is in GOROOT, then the in-process code works fine
// and we should keep using it. Moreover, the 'go list' approach below doesn't
// take standard-library vendoring into account and will fail.
if _, ok := ctxt.hasSubdir(filepath.Join(ctxt.GOROOT, "src"), absSrcDir); ok {
return errNoModules
}
}
// For efficiency, if path is a standard library package, let the usual lookup code handle it.
if ctxt.GOROOT != "" {
dir := ctxt.joinPath(ctxt.GOROOT, "src", path)
if ctxt.isDir(dir) {
return errNoModules
}
}
// If GO111MODULE=auto, look to see if there is a go.mod.
// Since go1.13, it doesn't matter if we're inside GOPATH.
if go111Module == "auto" {
var (
parent string
err error
)
if ctxt.Dir == "" {
parent, err = os.Getwd()
if err != nil {
// A nonexistent working directory can't be in a module.
return errNoModules
}
} else {
parent, err = filepath.Abs(ctxt.Dir)
if err != nil {
// If the caller passed a bogus Dir explicitly, that's materially
// different from not having modules enabled.
return err
}
}
for {
if f, err := ctxt.openFile(ctxt.joinPath(parent, "go.mod")); err == nil {
buf := make([]byte, 100)
_, err := f.Read(buf)
f.Close()
if err == nil || err == io.EOF {
// go.mod exists and is readable (is a file, not a directory).
break
}
}
d := filepath.Dir(parent)
if len(d) >= len(parent) {
return errNoModules // reached top of file system, no go.mod
}
parent = d
}
}
cmd := exec.Command("go", "list", "-e", "-compiler="+ctxt.Compiler, "-tags="+strings.Join(ctxt.BuildTags, ","), "-installsuffix="+ctxt.InstallSuffix, "-f={{.Dir}}\n{{.ImportPath}}\n{{.Root}}\n{{.Goroot}}\n{{if .Error}}{{.Error}}{{end}}\n", "--", path)
if ctxt.Dir != "" {
cmd.Dir = ctxt.Dir
}
var stdout, stderr strings.Builder
cmd.Stdout = &stdout
cmd.Stderr = &stderr
cgo := "0"
if ctxt.CgoEnabled {
cgo = "1"
}
cmd.Env = append(os.Environ(),
"GOOS="+ctxt.GOOS,
"GOARCH="+ctxt.GOARCH,
"GOROOT="+ctxt.GOROOT,
"GOPATH="+ctxt.GOPATH,
"CGO_ENABLED="+cgo,
)
if err := cmd.Run(); err != nil {
return fmt.Errorf("go/build: go list %s: %v\n%s\n", path, err, stderr.String())
}
f := strings.SplitN(stdout.String(), "\n", 5)
if len(f) != 5 {
return fmt.Errorf("go/build: importGo %s: unexpected output:\n%s\n", path, stdout.String())
}
dir := f[0]
errStr := strings.TrimSpace(f[4])
if errStr != "" && dir == "" {
// If 'go list' could not locate the package (dir is empty),
// return the same error that 'go list' reported.
return errors.New(errStr)
}
// If 'go list' did locate the package, ignore the error.
// It was probably related to loading source files, and we'll
// encounter it ourselves shortly if the FindOnly flag isn't set.
p.Dir = dir
p.ImportPath = f[1]
p.Root = f[2]
p.Goroot = f[3] == "true"
return nil
}
func equal(x, y []string) bool {
if len(x) != len(y) {
return false
}
for i, xi := range x {
if xi != y[i] {
return false
}
}
return true
}
// hasGoFiles reports whether dir contains any files with names ending in .go.
// For a vendor check we must exclude directories that contain no .go files.
// Otherwise it is not possible to vendor just a/b/c and still import the
// non-vendored a/b. See golang.org/issue/13832.
func hasGoFiles(ctxt *Context, dir string) bool {
ents, _ := ctxt.readDir(dir)
for _, ent := range ents {
if !ent.IsDir() && strings.HasSuffix(ent.Name(), ".go") {
return true
}
}
return false
}
func findImportComment(data []byte) (s string, line int) {
// expect keyword package
word, data := parseWord(data)
if string(word) != "package" {
return "", 0
}
// expect package name
_, data = parseWord(data)
// now ready for import comment, a // or /* */ comment
// beginning and ending on the current line.
for len(data) > 0 && (data[0] == ' ' || data[0] == '\t' || data[0] == '\r') {
data = data[1:]
}
var comment []byte
switch {
case bytes.HasPrefix(data, slashSlash):
i := bytes.Index(data, newline)
if i < 0 {
i = len(data)
}
comment = data[2:i]
case bytes.HasPrefix(data, slashStar):
data = data[2:]
i := bytes.Index(data, starSlash)
if i < 0 {
// malformed comment
return "", 0
}
comment = data[:i]
if bytes.Contains(comment, newline) {
return "", 0
}
}
comment = bytes.TrimSpace(comment)
// split comment into `import`, `"pkg"`
word, arg := parseWord(comment)
if string(word) != "import" {
return "", 0
}
line = 1 + bytes.Count(data[:cap(data)-cap(arg)], newline)
return strings.TrimSpace(string(arg)), line
}
var (
slashSlash = []byte("//")
slashStar = []byte("/*")
starSlash = []byte("*/")
newline = []byte("\n")
)
// skipSpaceOrComment returns data with any leading spaces or comments removed.
func skipSpaceOrComment(data []byte) []byte {
for len(data) > 0 {
switch data[0] {
case ' ', '\t', '\r', '\n':
data = data[1:]
continue
case '/':
if bytes.HasPrefix(data, slashSlash) {
i := bytes.Index(data, newline)
if i < 0 {
return nil
}
data = data[i+1:]
continue
}
if bytes.HasPrefix(data, slashStar) {
data = data[2:]
i := bytes.Index(data, starSlash)
if i < 0 {
return nil
}
data = data[i+2:]
continue
}
}
break
}
return data
}
// parseWord skips any leading spaces or comments in data
// and then parses the beginning of data as an identifier or keyword,
// returning that word and what remains after the word.
func parseWord(data []byte) (word, rest []byte) {
data = skipSpaceOrComment(data)
// Parse past leading word characters.
rest = data
for {
r, size := utf8.DecodeRune(rest)
if unicode.IsLetter(r) || '0' <= r && r <= '9' || r == '_' {
rest = rest[size:]
continue
}
break
}
word = data[:len(data)-len(rest)]
if len(word) == 0 {
return nil, nil
}
return word, rest
}
// MatchFile reports whether the file with the given name in the given directory
// matches the context and would be included in a Package created by ImportDir
// of that directory.
//
// MatchFile considers the name of the file and may use ctxt.OpenFile to
// read some or all of the file's content.
func (ctxt *Context) MatchFile(dir, name string) (match bool, err error) {
info, err := ctxt.matchFile(dir, name, nil, nil, nil)
return info != nil, err
}
var dummyPkg Package
// fileInfo records information learned about a file included in a build.
type fileInfo struct {
name string // full name including dir
header []byte
fset *token.FileSet
parsed *ast.File
parseErr error
imports []fileImport
embeds []fileEmbed
embedErr error
}
type fileImport struct {
path string
pos token.Pos
doc *ast.CommentGroup
}
type fileEmbed struct {
pattern string
pos token.Position
}
// matchFile determines whether the file with the given name in the given directory
// should be included in the package being constructed.
// If the file should be included, matchFile returns a non-nil *fileInfo (and a nil error).
// Non-nil errors are reserved for unexpected problems.
//
// If name denotes a Go program, matchFile reads until the end of the
// imports and returns that section of the file in the fileInfo's header field,
// even though it only considers text until the first non-comment
// for +build lines.
//
// If allTags is non-nil, matchFile records any encountered build tag
// by setting allTags[tag] = true.
func (ctxt *Context) matchFile(dir, name string, allTags map[string]bool, binaryOnly *bool, fset *token.FileSet) (*fileInfo, error) {
if strings.HasPrefix(name, "_") ||
strings.HasPrefix(name, ".") {
return nil, nil
}
i := strings.LastIndex(name, ".")
if i < 0 {
i = len(name)
}
ext := name[i:]
if !ctxt.goodOSArchFile(name, allTags) && !ctxt.UseAllFiles {
return nil, nil
}
if ext != ".go" && fileListForExt(&dummyPkg, ext) == nil {
// skip
return nil, nil
}
info := &fileInfo{name: ctxt.joinPath(dir, name), fset: fset}
if ext == ".syso" {
// binary, no reading
return info, nil
}
f, err := ctxt.openFile(info.name)
if err != nil {
return nil, err
}
if strings.HasSuffix(name, ".go") {
err = readGoInfo(f, info)
if strings.HasSuffix(name, "_test.go") {
binaryOnly = nil // ignore //go:binary-only-package comments in _test.go files
}
} else {
binaryOnly = nil // ignore //go:binary-only-package comments in non-Go sources
info.header, err = readComments(f)
}
f.Close()
if err != nil {
return nil, fmt.Errorf("read %s: %v", info.name, err)
}
// Look for +build comments to accept or reject the file.
ok, sawBinaryOnly, err := ctxt.shouldBuild(info.header, allTags)
if err != nil {
return nil, fmt.Errorf("%s: %v", name, err)
}
if !ok && !ctxt.UseAllFiles {
return nil, nil
}
if binaryOnly != nil && sawBinaryOnly {
*binaryOnly = true
}
return info, nil
}
func cleanDecls(m map[string][]token.Position) ([]string, map[string][]token.Position) {
all := make([]string, 0, len(m))
for path := range m {
all = append(all, path)
}
sort.Strings(all)
return all, m
}
// Import is shorthand for Default.Import.
func Import(path, srcDir string, mode ImportMode) (*Package, error) {
return Default.Import(path, srcDir, mode)
}
// ImportDir is shorthand for Default.ImportDir.
func ImportDir(dir string, mode ImportMode) (*Package, error) {
return Default.ImportDir(dir, mode)
}
var (
bSlashSlash = []byte(slashSlash)
bStarSlash = []byte(starSlash)
bSlashStar = []byte(slashStar)
bPlusBuild = []byte("+build")
goBuildComment = []byte("//go:build")
errGoBuildWithoutBuild = errors.New("//go:build comment without // +build comment")
errMultipleGoBuild = errors.New("multiple //go:build comments")
)
func isGoBuildComment(line []byte) bool {
if !bytes.HasPrefix(line, goBuildComment) {
return false
}
line = bytes.TrimSpace(line)
rest := line[len(goBuildComment):]
return len(rest) == 0 || len(bytes.TrimSpace(rest)) < len(rest)
}
// Special comment denoting a binary-only package.
// See https://golang.org/design/2775-binary-only-packages
// for more about the design of binary-only packages.
var binaryOnlyComment = []byte("//go:binary-only-package")
// shouldBuild reports whether it is okay to use this file,
// The rule is that in the file's leading run of // comments
// and blank lines, which must be followed by a blank line
// (to avoid including a Go package clause doc comment),
// lines beginning with '// +build' are taken as build directives.
//
// The file is accepted only if each such line lists something
// matching the file. For example:
//
// // +build windows linux
//
// marks the file as applicable only on Windows and Linux.
//
// For each build tag it consults, shouldBuild sets allTags[tag] = true.
//
// shouldBuild reports whether the file should be built
// and whether a //go:binary-only-package comment was found.
func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool) (shouldBuild, binaryOnly bool, err error) {
// Identify leading run of // comments and blank lines,
// which must be followed by a blank line.
// Also identify any //go:build comments.
content, goBuild, sawBinaryOnly, err := parseFileHeader(content)
if err != nil {
return false, false, err
}
// If //go:build line is present, it controls.
// Otherwise fall back to +build processing.
switch {
case goBuild != nil:
x, err := constraint.Parse(string(goBuild))
if err != nil {
return false, false, fmt.Errorf("parsing //go:build line: %v", err)
}
shouldBuild = ctxt.eval(x, allTags)
default:
shouldBuild = true
p := content
for len(p) > 0 {
line := p
if i := bytes.IndexByte(line, '\n'); i >= 0 {
line, p = line[:i], p[i+1:]
} else {
p = p[len(p):]
}
line = bytes.TrimSpace(line)
if !bytes.HasPrefix(line, bSlashSlash) || !bytes.Contains(line, bPlusBuild) {
continue
}
text := string(line)
if !constraint.IsPlusBuild(text) {
continue
}
if x, err := constraint.Parse(text); err == nil {
if !ctxt.eval(x, allTags) {
shouldBuild = false
}
}
}
}
return shouldBuild, sawBinaryOnly, nil
}
func parseFileHeader(content []byte) (trimmed, goBuild []byte, sawBinaryOnly bool, err error) {
end := 0
p := content
ended := false // found non-blank, non-// line, so stopped accepting // +build lines
inSlashStar := false // in /* */ comment
Lines:
for len(p) > 0 {
line := p
if i := bytes.IndexByte(line, '\n'); i >= 0 {
line, p = line[:i], p[i+1:]
} else {
p = p[len(p):]
}
line = bytes.TrimSpace(line)
if len(line) == 0 && !ended { // Blank line
// Remember position of most recent blank line.
// When we find the first non-blank, non-// line,
// this "end" position marks the latest file position
// where a // +build line can appear.
// (It must appear _before_ a blank line before the non-blank, non-// line.
// Yes, that's confusing, which is part of why we moved to //go:build lines.)
// Note that ended==false here means that inSlashStar==false,
// since seeing a /* would have set ended==true.
end = len(content) - len(p)
continue Lines
}
if !bytes.HasPrefix(line, slashSlash) { // Not comment line
ended = true
}
if !inSlashStar && isGoBuildComment(line) {
if goBuild != nil {
return nil, nil, false, errMultipleGoBuild
}
goBuild = line
}
if !inSlashStar && bytes.Equal(line, binaryOnlyComment) {
sawBinaryOnly = true
}
Comments:
for len(line) > 0 {
if inSlashStar {
if i := bytes.Index(line, starSlash); i >= 0 {
inSlashStar = false
line = bytes.TrimSpace(line[i+len(starSlash):])
continue Comments
}
continue Lines
}
if bytes.HasPrefix(line, bSlashSlash) {
continue Lines
}
if bytes.HasPrefix(line, bSlashStar) {
inSlashStar = true
line = bytes.TrimSpace(line[len(bSlashStar):])
continue Comments
}
// Found non-comment text.
break Lines
}
}
return content[:end], goBuild, sawBinaryOnly, nil
}
// saveCgo saves the information from the #cgo lines in the import "C" comment.
// These lines set CFLAGS, CPPFLAGS, CXXFLAGS and LDFLAGS and pkg-config directives
// that affect the way cgo's C code is built.
func (ctxt *Context) saveCgo(filename string, di *Package, cg *ast.CommentGroup) error {
text := cg.Text()
for _, line := range strings.Split(text, "\n") {
orig := line
// Line is
// #cgo [GOOS/GOARCH...] LDFLAGS: stuff
//
line = strings.TrimSpace(line)
if len(line) < 5 || line[:4] != "#cgo" || (line[4] != ' ' && line[4] != '\t') {
continue
}
// Split at colon.
line = strings.TrimSpace(line[4:])
i := strings.Index(line, ":")
if i < 0 {
return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
}
line, argstr := line[:i], line[i+1:]
// Parse GOOS/GOARCH stuff.
f := strings.Fields(line)
if len(f) < 1 {
return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
}
cond, verb := f[:len(f)-1], f[len(f)-1]
if len(cond) > 0 {
ok := false
for _, c := range cond {
if ctxt.matchAuto(c, nil) {
ok = true
break
}
}
if !ok {
continue
}
}
args, err := splitQuoted(argstr)
if err != nil {
return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
}
var ok bool
for i, arg := range args {
if arg, ok = expandSrcDir(arg, di.Dir); !ok {
return fmt.Errorf("%s: malformed #cgo argument: %s", filename, arg)
}
args[i] = arg
}
switch verb {
case "CFLAGS", "CPPFLAGS", "CXXFLAGS", "FFLAGS", "LDFLAGS":
// Change relative paths to absolute.
ctxt.makePathsAbsolute(args, di.Dir)
}
switch verb {
case "CFLAGS":
di.CgoCFLAGS = append(di.CgoCFLAGS, args...)
case "CPPFLAGS":
di.CgoCPPFLAGS = append(di.CgoCPPFLAGS, args...)
case "CXXFLAGS":
di.CgoCXXFLAGS = append(di.CgoCXXFLAGS, args...)
case "FFLAGS":
di.CgoFFLAGS = append(di.CgoFFLAGS, args...)
case "LDFLAGS":
di.CgoLDFLAGS = append(di.CgoLDFLAGS, args...)
case "pkg-config":
di.CgoPkgConfig = append(di.CgoPkgConfig, args...)
default:
return fmt.Errorf("%s: invalid #cgo verb: %s", filename, orig)
}
}
return nil
}
// expandSrcDir expands any occurrence of ${SRCDIR}, making sure
// the result is safe for the shell.
func expandSrcDir(str string, srcdir string) (string, bool) {
// "\" delimited paths cause safeCgoName to fail
// so convert native paths with a different delimiter
// to "/" before starting (eg: on windows).
srcdir = filepath.ToSlash(srcdir)
chunks := strings.Split(str, "${SRCDIR}")
if len(chunks) < 2 {
return str, safeCgoName(str)
}
ok := true
for _, chunk := range chunks {
ok = ok && (chunk == "" || safeCgoName(chunk))
}
ok = ok && (srcdir == "" || safeCgoName(srcdir))
res := strings.Join(chunks, srcdir)
return res, ok && res != ""
}
// makePathsAbsolute looks for compiler options that take paths and
// makes them absolute. We do this because through the 1.8 release we
// ran the compiler in the package directory, so any relative -I or -L
// options would be relative to that directory. In 1.9 we changed to
// running the compiler in the build directory, to get consistent
// build results (issue #19964). To keep builds working, we change any
// relative -I or -L options to be absolute.
//
// Using filepath.IsAbs and filepath.Join here means the results will be
// different on different systems, but that's OK: -I and -L options are
// inherently system-dependent.
func (ctxt *Context) makePathsAbsolute(args []string, srcDir string) {
nextPath := false
for i, arg := range args {
if nextPath {
if !filepath.IsAbs(arg) {
args[i] = filepath.Join(srcDir, arg)
}
nextPath = false
} else if strings.HasPrefix(arg, "-I") || strings.HasPrefix(arg, "-L") {
if len(arg) == 2 {
nextPath = true
} else {
if !filepath.IsAbs(arg[2:]) {
args[i] = arg[:2] + filepath.Join(srcDir, arg[2:])
}
}
}
}
}
// NOTE: $ is not safe for the shell, but it is allowed here because of linker options like -Wl,$ORIGIN.
// We never pass these arguments to a shell (just to programs we construct argv for), so this should be okay.
// See golang.org/issue/6038.
// The @ is for OS X. See golang.org/issue/13720.
// The % is for Jenkins. See golang.org/issue/16959.
// The ! is because module paths may use them. See golang.org/issue/26716.
// The ~ and ^ are for sr.ht. See golang.org/issue/32260.
const safeString = "+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:$@%! ~^"
func safeCgoName(s string) bool {
if s == "" {
return false
}
for i := 0; i < len(s); i++ {
if c := s[i]; c < utf8.RuneSelf && strings.IndexByte(safeString, c) < 0 {
return false
}
}
return true
}
// splitQuoted splits the string s around each instance of one or more consecutive
// white space characters while taking into account quotes and escaping, and
// returns an array of substrings of s or an empty list if s contains only white space.
// Single quotes and double quotes are recognized to prevent splitting within the
// quoted region, and are removed from the resulting substrings. If a quote in s
// isn't closed err will be set and r will have the unclosed argument as the
// last element. The backslash is used for escaping.
//
// For example, the following string:
//
// a b:"c d" 'e''f' "g\""
//
// Would be parsed as:
//
// []string{"a", "b:c d", "ef", `g"`}
//
func splitQuoted(s string) (r []string, err error) {
var args []string
arg := make([]rune, len(s))
escaped := false
quoted := false
quote := '\x00'
i := 0
for _, rune := range s {
switch {
case escaped:
escaped = false
case rune == '\\':
escaped = true
continue
case quote != '\x00':
if rune == quote {
quote = '\x00'
continue
}
case rune == '"' || rune == '\'':
quoted = true
quote = rune
continue
case unicode.IsSpace(rune):
if quoted || i > 0 {
quoted = false
args = append(args, string(arg[:i]))
i = 0
}
continue
}
arg[i] = rune
i++
}
if quoted || i > 0 {
args = append(args, string(arg[:i]))
}
if quote != 0 {
err = errors.New("unclosed quote")
} else if escaped {
err = errors.New("unfinished escaping")
}
return args, err
}
// matchAuto interprets text as either a +build or //go:build expression (whichever works),
// reporting whether the expression matches the build context.
//
// matchAuto is only used for testing of tag evaluation
// and in #cgo lines, which accept either syntax.
func (ctxt *Context) matchAuto(text string, allTags map[string]bool) bool {
if strings.ContainsAny(text, "&|()") {
text = "//go:build " + text
} else {
text = "// +build " + text
}
x, err := constraint.Parse(text)
if err != nil {
return false
}
return ctxt.eval(x, allTags)
}
func (ctxt *Context) eval(x constraint.Expr, allTags map[string]bool) bool {
return x.Eval(func(tag string) bool { return ctxt.matchTag(tag, allTags) })
}
// matchTag reports whether the name is one of:
//
// cgo (if cgo is enabled)
// $GOOS
// $GOARCH
// ctxt.Compiler
// linux (if GOOS = android)
// solaris (if GOOS = illumos)
// tag (if tag is listed in ctxt.BuildTags or ctxt.ReleaseTags)
//
// It records all consulted tags in allTags.
func (ctxt *Context) matchTag(name string, allTags map[string]bool) bool {
if allTags != nil {
allTags[name] = true
}
// special tags
if ctxt.CgoEnabled && name == "cgo" {
return true
}
if name == ctxt.GOOS || name == ctxt.GOARCH || name == ctxt.Compiler {
return true
}
if ctxt.GOOS == "android" && name == "linux" {
return true
}
if ctxt.GOOS == "illumos" && name == "solaris" {
return true
}
if ctxt.GOOS == "ios" && name == "darwin" {
return true
}
// other tags
for _, tag := range ctxt.BuildTags {
if tag == name {
return true
}
}
for _, tag := range ctxt.ToolTags {
if tag == name {
return true
}
}
for _, tag := range ctxt.ReleaseTags {
if tag == name {
return true
}
}
return false
}
// goodOSArchFile returns false if the name contains a $GOOS or $GOARCH
// suffix which does not match the current system.
// The recognized name formats are:
//
// name_$(GOOS).*
// name_$(GOARCH).*
// name_$(GOOS)_$(GOARCH).*
// name_$(GOOS)_test.*
// name_$(GOARCH)_test.*
// name_$(GOOS)_$(GOARCH)_test.*
//
// Exceptions:
// if GOOS=android, then files with GOOS=linux are also matched.
// if GOOS=illumos, then files with GOOS=solaris are also matched.
// if GOOS=ios, then files with GOOS=darwin are also matched.
func (ctxt *Context) goodOSArchFile(name string, allTags map[string]bool) bool {
if dot := strings.Index(name, "."); dot != -1 {
name = name[:dot]
}
// Before Go 1.4, a file called "linux.go" would be equivalent to having a
// build tag "linux" in that file. For Go 1.4 and beyond, we require this
// auto-tagging to apply only to files with a non-empty prefix, so
// "foo_linux.go" is tagged but "linux.go" is not. This allows new operating
// systems, such as android, to arrive without breaking existing code with
// innocuous source code in "android.go". The easiest fix: cut everything
// in the name before the initial _.
i := strings.Index(name, "_")
if i < 0 {
return true
}
name = name[i:] // ignore everything before first _
l := strings.Split(name, "_")
if n := len(l); n > 0 && l[n-1] == "test" {
l = l[:n-1]
}
n := len(l)
if n >= 2 && knownOS[l[n-2]] && knownArch[l[n-1]] {
return ctxt.matchTag(l[n-1], allTags) && ctxt.matchTag(l[n-2], allTags)
}
if n >= 1 && (knownOS[l[n-1]] || knownArch[l[n-1]]) {
return ctxt.matchTag(l[n-1], allTags)
}
return true
}
var knownOS = make(map[string]bool)
var knownArch = make(map[string]bool)
func init() {
for _, v := range strings.Fields(goosList) {
knownOS[v] = true
}
for _, v := range strings.Fields(goarchList) {
knownArch[v] = true
}
}
// ToolDir is the directory containing build tools.
var ToolDir = getToolDir()
// IsLocalImport reports whether the import path is
// a local import path, like ".", "..", "./foo", or "../foo".
func IsLocalImport(path string) bool {
return path == "." || path == ".." ||
strings.HasPrefix(path, "./") || strings.HasPrefix(path, "../")
}
// ArchChar returns "?" and an error.
// In earlier versions of Go, the returned string was used to derive
// the compiler and linker tool names, the default object file suffix,
// and the default linker output name. As of Go 1.5, those strings
// no longer vary by architecture; they are compile, link, .o, and a.out, respectively.
func ArchChar(goarch string) (string, error) {
return "?", errors.New("architecture letter no longer used")
}