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Commit 38a03de6 authored by Russ Cox's avatar Russ Cox
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go/build: move code around 

Only copy+paste here.
Will make next code review's diffs a bit smaller.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5704050
parent 6e2ae0a1
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Inline Side-by-side
Showing with 716 additions and 720 deletions
src/pkg/go/build/build.go
View file @ 38a03de6
......@@ -2,10 +2,724 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package build provides tools for building Go packages.
// Package build gathers information about Go packages.
//
// Go Path
//
// TODO: Document GOPATH.
//
// Build Constraints
//
// A build constraint is a line comment beginning with the directive +build
// that lists the conditions under which a file should be included in the package.
// Constraints may appear in any kind of source file (not just Go), but
// they must be appear near the top of the file, preceded
// only by blank lines and other line comments.
//
// A build constraint is evaluated as the OR of space-separated options;
// each option evaluates as the AND of its comma-separated terms;
// and each term is an alphanumeric word or, preceded by !, its negation.
// That is, the build constraint:
//
// // +build linux,386 darwin,!cgo
//
// corresponds to the boolean formula:
//
// (linux AND 386) OR (darwin AND (NOT cgo))
//
// During a particular build, the following words are satisfied:
//
// - the target operating system, as spelled by runtime.GOOS
// - the target architecture, as spelled by runtime.GOARCH
// - "cgo", if ctxt.CgoEnabled is true
// - any additional words listed in ctxt.BuildTags
//
// If a file's name, after stripping the extension and a possible _test suffix,
// matches *_GOOS, *_GOARCH, or *_GOOS_GOARCH for any known operating
// system and architecture values, then the file is considered to have an implicit
// build constraint requiring those terms.
//
// To keep a file from being considered for the build:
//
// // +build ignore
//
// (any other unsatisfied word will work as well, but ``ignore'' is conventional.)
//
// To build a file only when using cgo, and only on Linux and OS X:
//
// // +build linux,cgo darwin,cgo
//
// Such a file is usually paired with another file implementing the
// default functionality for other systems, which in this case would
// carry the constraint:
//
// // +build !linux !darwin !cgo
//
// Naming a file dns_windows.go will cause it to be included only when
// building the package for Windows; similarly, math_386.s will be included
// only when building the package for 32-bit x86.
//
package build
import "errors"
import (
"bytes"
"errors"
"fmt"
"go/ast"
"go/parser"
"go/token"
"io/ioutil"
"log"
"os"
"path"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"unicode"
)
// A Context specifies the supporting context for a build.
type Context struct {
GOARCH string // target architecture
GOOS string // target operating system
CgoEnabled bool // whether cgo can be used
BuildTags []string // additional tags to recognize in +build lines
UseAllFiles bool // use files regardless of +build lines, file names
// By default, ScanDir uses the operating system's
// file system calls to read directories and files.
// Callers can override those calls to provide other
// ways to read data by setting ReadDir and ReadFile.
// ScanDir does not make any assumptions about the
// format of the strings dir and file: they can be
// slash-separated, backslash-separated, even URLs.
// ReadDir returns a slice of os.FileInfo, sorted by Name,
// describing the content of the named directory.
// The dir argument is the argument to ScanDir.
// If ReadDir is nil, ScanDir uses io.ReadDir.
ReadDir func(dir string) (fi []os.FileInfo, err error)
// ReadFile returns the content of the file named file
// in the directory named dir. The dir argument is the
// argument to ScanDir, and the file argument is the
// Name field from an os.FileInfo returned by ReadDir.
// The returned path is the full name of the file, to be
// used in error messages.
//
// If ReadFile is nil, ScanDir uses filepath.Join(dir, file)
// as the path and ioutil.ReadFile to read the data.
ReadFile func(dir, file string) (path string, content []byte, err error)
}
func (ctxt *Context) readDir(dir string) ([]os.FileInfo, error) {
if f := ctxt.ReadDir; f != nil {
return f(dir)
}
return ioutil.ReadDir(dir)
}
func (ctxt *Context) readFile(dir, file string) (string, []byte, error) {
if f := ctxt.ReadFile; f != nil {
return f(dir, file)
}
p := filepath.Join(dir, file)
content, err := ioutil.ReadFile(p)
return p, content, err
}
// The DefaultContext is the default Context for builds.
// It uses the GOARCH and GOOS environment variables
// if set, or else the compiled code's GOARCH and GOOS.
var DefaultContext Context = defaultContext()
var cgoEnabled = map[string]bool{
"darwin/386": true,
"darwin/amd64": true,
"linux/386": true,
"linux/amd64": true,
"freebsd/386": true,
"freebsd/amd64": true,
"windows/386": true,
"windows/amd64": true,
}
func defaultContext() Context {
var c Context
c.GOARCH = envOr("GOARCH", runtime.GOARCH)
c.GOOS = envOr("GOOS", runtime.GOOS)
s := os.Getenv("CGO_ENABLED")
switch s {
case "1":
c.CgoEnabled = true
case "0":
c.CgoEnabled = false
default:
c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
}
return c
}
func envOr(name, def string) string {
s := os.Getenv(name)
if s == "" {
return def
}
return s
}
type DirInfo struct {
Package string // Name of package in dir
PackageComment *ast.CommentGroup // Package comments from GoFiles
ImportPath string // Import path of package in dir
Imports []string // All packages imported by GoFiles
ImportPos map[string][]token.Position // Source code location of imports
// Source files
GoFiles []string // .go files in dir (excluding CgoFiles, TestGoFiles, XTestGoFiles)
HFiles []string // .h files in dir
CFiles []string // .c files in dir
SFiles []string // .s (and, when using cgo, .S files in dir)
CgoFiles []string // .go files that import "C"
// Cgo directives
CgoPkgConfig []string // Cgo pkg-config directives
CgoCFLAGS []string // Cgo CFLAGS directives
CgoLDFLAGS []string // Cgo LDFLAGS directives
// Test information
TestGoFiles []string // _test.go files in package
XTestGoFiles []string // _test.go files outside package
TestImports []string // All packages imported by (X)TestGoFiles
TestImportPos map[string][]token.Position
}
func (d *DirInfo) IsCommand() bool {
// TODO(rsc): This is at least a little bogus.
return d.Package == "main"
}
// ScanDir calls DefaultContext.ScanDir.
func ScanDir(dir string) (info *DirInfo, err error) {
return DefaultContext.ScanDir(dir)
}
// TODO(rsc): Move this comment to a more appropriate place.
// ScanDir returns a structure with details about the Go package
// found in the given directory.
//
// Most .go, .c, .h, and .s files in the directory are considered part
// of the package. The exceptions are:
//
// - .go files in package main (unless no other package is found)
// - .go files in package documentation
// - files starting with _ or .
// - files with build constraints not satisfied by the context
//
func (ctxt *Context) ScanDir(dir string) (info *DirInfo, err error) {
dirs, err := ctxt.readDir(dir)
if err != nil {
return nil, err
}
var Sfiles []string // files with ".S" (capital S)
var di DirInfo
var firstFile string
imported := make(map[string][]token.Position)
testImported := make(map[string][]token.Position)
fset := token.NewFileSet()
for _, d := range dirs {
if d.IsDir() {
continue
}
name := d.Name()
if strings.HasPrefix(name, "_") ||
strings.HasPrefix(name, ".") {
continue
}
if !ctxt.UseAllFiles && !ctxt.goodOSArchFile(name) {
continue
}
ext := path.Ext(name)
switch ext {
case ".go", ".c", ".s", ".h", ".S":
// tentatively okay
default:
// skip
continue
}
filename, data, err := ctxt.readFile(dir, name)
if err != nil {
return nil, err
}
// Look for +build comments to accept or reject the file.
if !ctxt.UseAllFiles && !ctxt.shouldBuild(data) {
continue
}
// Going to save the file. For non-Go files, can stop here.
switch ext {
case ".c":
di.CFiles = append(di.CFiles, name)
continue
case ".h":
di.HFiles = append(di.HFiles, name)
continue
case ".s":
di.SFiles = append(di.SFiles, name)
continue
case ".S":
Sfiles = append(Sfiles, name)
continue
}
pf, err := parser.ParseFile(fset, filename, data, parser.ImportsOnly|parser.ParseComments)
if err != nil {
return nil, err
}
pkg := string(pf.Name.Name)
if pkg == "documentation" {
continue
}
isTest := strings.HasSuffix(name, "_test.go")
if isTest && strings.HasSuffix(pkg, "_test") {
pkg = pkg[:len(pkg)-len("_test")]
}
if di.Package == "" {
di.Package = pkg
firstFile = name
} else if pkg != di.Package {
return nil, fmt.Errorf("%s: found packages %s (%s) and %s (%s)", dir, di.Package, firstFile, pkg, name)
}
if pf.Doc != nil {
if di.PackageComment != nil {
di.PackageComment.List = append(di.PackageComment.List, pf.Doc.List...)
} else {
di.PackageComment = pf.Doc
}
}
// Record imports and information about cgo.
isCgo := false
for _, decl := range pf.Decls {
d, ok := decl.(*ast.GenDecl)
if !ok {
continue
}
for _, dspec := range d.Specs {
spec, ok := dspec.(*ast.ImportSpec)
if !ok {
continue
}
quoted := string(spec.Path.Value)
path, err := strconv.Unquote(quoted)
if err != nil {
log.Panicf("%s: parser returned invalid quoted string: <%s>", filename, quoted)
}
if isTest {
testImported[path] = append(testImported[path], fset.Position(spec.Pos()))
} else {
imported[path] = append(imported[path], fset.Position(spec.Pos()))
}
if path == "C" {
if isTest {
return nil, fmt.Errorf("%s: use of cgo in test not supported", filename)
}
cg := spec.Doc
if cg == nil && len(d.Specs) == 1 {
cg = d.Doc
}
if cg != nil {
if err := ctxt.saveCgo(filename, &di, cg); err != nil {
return nil, err
}
}
isCgo = true
}
}
}
if isCgo {
if ctxt.CgoEnabled {
di.CgoFiles = append(di.CgoFiles, name)
}
} else if isTest {
if pkg == string(pf.Name.Name) {
di.TestGoFiles = append(di.TestGoFiles, name)
} else {
di.XTestGoFiles = append(di.XTestGoFiles, name)
}
} else {
di.GoFiles = append(di.GoFiles, name)
}
}
if di.Package == "" {
return nil, fmt.Errorf("%s: no Go source files", dir)
}
di.Imports = make([]string, len(imported))
di.ImportPos = imported
i := 0
for p := range imported {
di.Imports[i] = p
i++
}
di.TestImports = make([]string, len(testImported))
di.TestImportPos = testImported
i = 0
for p := range testImported {
di.TestImports[i] = p
i++
}
// add the .S files only if we are using cgo
// (which means gcc will compile them).
// The standard assemblers expect .s files.
if len(di.CgoFiles) > 0 {
di.SFiles = append(di.SFiles, Sfiles...)
sort.Strings(di.SFiles)
}
// File name lists are sorted because ReadDir sorts.
sort.Strings(di.Imports)
sort.Strings(di.TestImports)
return &di, nil
}
var slashslash = []byte("//")
// 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.
//
func (ctxt *Context) shouldBuild(content []byte) bool {
// Pass 1. Identify leading run of // comments and blank lines,
// which must be followed by a blank line.
end := 0
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 len(line) == 0 { // Blank line
end = cap(content) - cap(line) // &line[0] - &content[0]
continue
}
if !bytes.HasPrefix(line, slashslash) { // Not comment line
break
}
}
content = content[:end]
// Pass 2. Process each line in the run.
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, slashslash) {
line = bytes.TrimSpace(line[len(slashslash):])
if len(line) > 0 && line[0] == '+' {
// Looks like a comment +line.
f := strings.Fields(string(line))
if f[0] == "+build" {
ok := false
for _, tok := range f[1:] {
if ctxt.match(tok) {
ok = true
break
}
}
if !ok {
return false // this one doesn't match
}
}
}
}
}
return true // everything matches
}
// saveCgo saves the information from the #cgo lines in the import "C" comment.
// These lines set CFLAGS and LDFLAGS and pkg-config directives that affect
// the way cgo's C code is built.
//
// TODO(rsc): This duplicates code in cgo.
// Once the dust settles, remove this code from cgo.
func (ctxt *Context) saveCgo(filename string, di *DirInfo, 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.match(c) {
ok = true
break
}
}
if !ok {
continue
}
}
args, err := splitQuoted(argstr)
if err != nil {
return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
}
for _, arg := range args {
if !safeName(arg) {
return fmt.Errorf("%s: malformed #cgo argument: %s", filename, arg)
}
}
switch verb {
case "CFLAGS":
di.CgoCFLAGS = append(di.CgoCFLAGS, 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
}
var safeBytes = []byte("+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:")
func safeName(s string) bool {
if s == "" {
return false
}
for i := 0; i < len(s); i++ {
if c := s[i]; c < 0x80 && bytes.IndexByte(safeBytes, 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
}
// match returns true if the name is one of:
//
// $GOOS
// $GOARCH
// cgo (if cgo is enabled)
// !cgo (if cgo is disabled)
// tag (if tag is listed in ctxt.BuildTags)
// !tag (if tag is not listed in ctxt.BuildTags)
// a slash-separated list of any of these
//
func (ctxt *Context) match(name string) bool {
if name == "" {
return false
}
if i := strings.Index(name, ","); i >= 0 {
// comma-separated list
return ctxt.match(name[:i]) && ctxt.match(name[i+1:])
}
if strings.HasPrefix(name, "!!") { // bad syntax, reject always
return false
}
if strings.HasPrefix(name, "!") { // negation
return !ctxt.match(name[1:])
}
// Tags must be letters, digits, underscores.
// Unlike in Go identifiers, all digits is fine (e.g., "386").
for _, c := range name {
if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' {
return false
}
}
// special tags
if ctxt.CgoEnabled && name == "cgo" {
return true
}
if name == ctxt.GOOS || name == ctxt.GOARCH {
return true
}
// other tags
for _, tag := range ctxt.BuildTags {
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.*
//
func (ctxt *Context) goodOSArchFile(name string) bool {
if dot := strings.Index(name, "."); dot != -1 {
name = name[:dot]
}
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 l[n-2] == ctxt.GOOS && l[n-1] == ctxt.GOARCH
}
if n >= 1 && knownOS[l[n-1]] {
return l[n-1] == ctxt.GOOS
}
if n >= 1 && knownArch[l[n-1]] {
return l[n-1] == ctxt.GOARCH
}
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 = filepath.Join(runtime.GOROOT(), "pkg/tool/"+runtime.GOOS+"_"+runtime.GOARCH)
// isLocalPath returns whether the given path is local (/foo ./foo ../foo . ..)
// Windows paths that starts with drive letter (c:\foo c:foo) are considered local.
func isLocalPath(s string) bool {
const sep = string(filepath.Separator)
return s == "." || s == ".." ||
filepath.HasPrefix(s, sep) ||
filepath.HasPrefix(s, "."+sep) || filepath.HasPrefix(s, ".."+sep) ||
filepath.VolumeName(s) != ""
}
// ArchChar returns the architecture character for the given goarch.
// For example, ArchChar("amd64") returns "6".
......
src/pkg/go/build/dir.go deleted 100644 → 0
View file @ 6e2ae0a1
// 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/parser"
"go/token"
"io/ioutil"
"log"
"os"
"path"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"unicode"
)
// A Context specifies the supporting context for a build.
type Context struct {
GOARCH string // target architecture
GOOS string // target operating system
CgoEnabled bool // whether cgo can be used
BuildTags []string // additional tags to recognize in +build lines
UseAllFiles bool // use files regardless of +build lines, file names
// By default, ScanDir uses the operating system's
// file system calls to read directories and files.
// Callers can override those calls to provide other
// ways to read data by setting ReadDir and ReadFile.
// ScanDir does not make any assumptions about the
// format of the strings dir and file: they can be
// slash-separated, backslash-separated, even URLs.
// ReadDir returns a slice of os.FileInfo, sorted by Name,
// describing the content of the named directory.
// The dir argument is the argument to ScanDir.
// If ReadDir is nil, ScanDir uses io.ReadDir.
ReadDir func(dir string) (fi []os.FileInfo, err error)
// ReadFile returns the content of the file named file
// in the directory named dir. The dir argument is the
// argument to ScanDir, and the file argument is the
// Name field from an os.FileInfo returned by ReadDir.
// The returned path is the full name of the file, to be
// used in error messages.
//
// If ReadFile is nil, ScanDir uses filepath.Join(dir, file)
// as the path and ioutil.ReadFile to read the data.
ReadFile func(dir, file string) (path string, content []byte, err error)
}
func (ctxt *Context) readDir(dir string) ([]os.FileInfo, error) {
if f := ctxt.ReadDir; f != nil {
return f(dir)
}
return ioutil.ReadDir(dir)
}
func (ctxt *Context) readFile(dir, file string) (string, []byte, error) {
if f := ctxt.ReadFile; f != nil {
return f(dir, file)
}
p := filepath.Join(dir, file)
content, err := ioutil.ReadFile(p)
return p, content, err
}
// The DefaultContext is the default Context for builds.
// It uses the GOARCH and GOOS environment variables
// if set, or else the compiled code's GOARCH and GOOS.
var DefaultContext Context = defaultContext()
var cgoEnabled = map[string]bool{
"darwin/386": true,
"darwin/amd64": true,
"linux/386": true,
"linux/amd64": true,
"freebsd/386": true,
"freebsd/amd64": true,
"windows/386": true,
"windows/amd64": true,
}
func defaultContext() Context {
var c Context
c.GOARCH = envOr("GOARCH", runtime.GOARCH)
c.GOOS = envOr("GOOS", runtime.GOOS)
s := os.Getenv("CGO_ENABLED")
switch s {
case "1":
c.CgoEnabled = true
case "0":
c.CgoEnabled = false
default:
c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
}
return c
}
func envOr(name, def string) string {
s := os.Getenv(name)
if s == "" {
return def
}
return s
}
type DirInfo struct {
Package string // Name of package in dir
PackageComment *ast.CommentGroup // Package comments from GoFiles
ImportPath string // Import path of package in dir
Imports []string // All packages imported by GoFiles
ImportPos map[string][]token.Position // Source code location of imports
// Source files
GoFiles []string // .go files in dir (excluding CgoFiles, TestGoFiles, XTestGoFiles)
HFiles []string // .h files in dir
CFiles []string // .c files in dir
SFiles []string // .s (and, when using cgo, .S files in dir)
CgoFiles []string // .go files that import "C"
// Cgo directives
CgoPkgConfig []string // Cgo pkg-config directives
CgoCFLAGS []string // Cgo CFLAGS directives
CgoLDFLAGS []string // Cgo LDFLAGS directives
// Test information
TestGoFiles []string // _test.go files in package
XTestGoFiles []string // _test.go files outside package
TestImports []string // All packages imported by (X)TestGoFiles
TestImportPos map[string][]token.Position
}
func (d *DirInfo) IsCommand() bool {
// TODO(rsc): This is at least a little bogus.
return d.Package == "main"
}
// ScanDir calls DefaultContext.ScanDir.
func ScanDir(dir string) (info *DirInfo, err error) {
return DefaultContext.ScanDir(dir)
}
// TODO(rsc): Move this comment to a more appropriate place.
// ScanDir returns a structure with details about the Go package
// found in the given directory.
//
// Most .go, .c, .h, and .s files in the directory are considered part
// of the package. The exceptions are:
//
// - .go files in package main (unless no other package is found)
// - .go files in package documentation
// - files starting with _ or .
// - files with build constraints not satisfied by the context
//
// Build Constraints
//
// A build constraint is a line comment beginning with the directive +build
// that lists the conditions under which a file should be included in the package.
// Constraints may appear in any kind of source file (not just Go), but
// they must be appear near the top of the file, preceded
// only by blank lines and other line comments.
//
// A build constraint is evaluated as the OR of space-separated options;
// each option evaluates as the AND of its comma-separated terms;
// and each term is an alphanumeric word or, preceded by !, its negation.
// That is, the build constraint:
//
// // +build linux,386 darwin,!cgo
//
// corresponds to the boolean formula:
//
// (linux AND 386) OR (darwin AND (NOT cgo))
//
// During a particular build, the following words are satisfied:
//
// - the target operating system, as spelled by runtime.GOOS
// - the target architecture, as spelled by runtime.GOARCH
// - "cgo", if ctxt.CgoEnabled is true
// - any additional words listed in ctxt.BuildTags
//
// If a file's name, after stripping the extension and a possible _test suffix,
// matches *_GOOS, *_GOARCH, or *_GOOS_GOARCH for any known operating
// system and architecture values, then the file is considered to have an implicit
// build constraint requiring those terms.
//
// Examples
//
// To keep a file from being considered for the build:
//
// // +build ignore
//
// (any other unsatisfied word will work as well, but ``ignore'' is conventional.)
//
// To build a file only when using cgo, and only on Linux and OS X:
//
// // +build linux,cgo darwin,cgo
//
// Such a file is usually paired with another file implementing the
// default functionality for other systems, which in this case would
// carry the constraint:
//
// // +build !linux !darwin !cgo
//
// Naming a file dns_windows.go will cause it to be included only when
// building the package for Windows; similarly, math_386.s will be included
// only when building the package for 32-bit x86.
//
func (ctxt *Context) ScanDir(dir string) (info *DirInfo, err error) {
dirs, err := ctxt.readDir(dir)
if err != nil {
return nil, err
}
var Sfiles []string // files with ".S" (capital S)
var di DirInfo
var firstFile string
imported := make(map[string][]token.Position)
testImported := make(map[string][]token.Position)
fset := token.NewFileSet()
for _, d := range dirs {
if d.IsDir() {
continue
}
name := d.Name()
if strings.HasPrefix(name, "_") ||
strings.HasPrefix(name, ".") {
continue
}
if !ctxt.UseAllFiles && !ctxt.goodOSArchFile(name) {
continue
}
ext := path.Ext(name)
switch ext {
case ".go", ".c", ".s", ".h", ".S":
// tentatively okay
default:
// skip
continue
}
filename, data, err := ctxt.readFile(dir, name)
if err != nil {
return nil, err
}
// Look for +build comments to accept or reject the file.
if !ctxt.UseAllFiles && !ctxt.shouldBuild(data) {
continue
}
// Going to save the file. For non-Go files, can stop here.
switch ext {
case ".c":
di.CFiles = append(di.CFiles, name)
continue
case ".h":
di.HFiles = append(di.HFiles, name)
continue
case ".s":
di.SFiles = append(di.SFiles, name)
continue
case ".S":
Sfiles = append(Sfiles, name)
continue
}
pf, err := parser.ParseFile(fset, filename, data, parser.ImportsOnly|parser.ParseComments)
if err != nil {
return nil, err
}
pkg := string(pf.Name.Name)
if pkg == "documentation" {
continue
}
isTest := strings.HasSuffix(name, "_test.go")
if isTest && strings.HasSuffix(pkg, "_test") {
pkg = pkg[:len(pkg)-len("_test")]
}
if di.Package == "" {
di.Package = pkg
firstFile = name
} else if pkg != di.Package {
return nil, fmt.Errorf("%s: found packages %s (%s) and %s (%s)", dir, di.Package, firstFile, pkg, name)
}
if pf.Doc != nil {
if di.PackageComment != nil {
di.PackageComment.List = append(di.PackageComment.List, pf.Doc.List...)
} else {
di.PackageComment = pf.Doc
}
}
// Record imports and information about cgo.
isCgo := false
for _, decl := range pf.Decls {
d, ok := decl.(*ast.GenDecl)
if !ok {
continue
}
for _, dspec := range d.Specs {
spec, ok := dspec.(*ast.ImportSpec)
if !ok {
continue
}
quoted := string(spec.Path.Value)
path, err := strconv.Unquote(quoted)
if err != nil {
log.Panicf("%s: parser returned invalid quoted string: <%s>", filename, quoted)
}
if isTest {
testImported[path] = append(testImported[path], fset.Position(spec.Pos()))
} else {
imported[path] = append(imported[path], fset.Position(spec.Pos()))
}
if path == "C" {
if isTest {
return nil, fmt.Errorf("%s: use of cgo in test not supported", filename)
}
cg := spec.Doc
if cg == nil && len(d.Specs) == 1 {
cg = d.Doc
}
if cg != nil {
if err := ctxt.saveCgo(filename, &di, cg); err != nil {
return nil, err
}
}
isCgo = true
}
}
}
if isCgo {
if ctxt.CgoEnabled {
di.CgoFiles = append(di.CgoFiles, name)
}
} else if isTest {
if pkg == string(pf.Name.Name) {
di.TestGoFiles = append(di.TestGoFiles, name)
} else {
di.XTestGoFiles = append(di.XTestGoFiles, name)
}
} else {
di.GoFiles = append(di.GoFiles, name)
}
}
if di.Package == "" {
return nil, fmt.Errorf("%s: no Go source files", dir)
}
di.Imports = make([]string, len(imported))
di.ImportPos = imported
i := 0
for p := range imported {
di.Imports[i] = p
i++
}
di.TestImports = make([]string, len(testImported))
di.TestImportPos = testImported
i = 0
for p := range testImported {
di.TestImports[i] = p
i++
}
// add the .S files only if we are using cgo
// (which means gcc will compile them).
// The standard assemblers expect .s files.
if len(di.CgoFiles) > 0 {
di.SFiles = append(di.SFiles, Sfiles...)
sort.Strings(di.SFiles)
}
// File name lists are sorted because ReadDir sorts.
sort.Strings(di.Imports)
sort.Strings(di.TestImports)
return &di, nil
}
var slashslash = []byte("//")
// 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.
//
func (ctxt *Context) shouldBuild(content []byte) bool {
// Pass 1. Identify leading run of // comments and blank lines,
// which must be followed by a blank line.
end := 0
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 len(line) == 0 { // Blank line
end = cap(content) - cap(line) // &line[0] - &content[0]
continue
}
if !bytes.HasPrefix(line, slashslash) { // Not comment line
break
}
}
content = content[:end]
// Pass 2. Process each line in the run.
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, slashslash) {
line = bytes.TrimSpace(line[len(slashslash):])
if len(line) > 0 && line[0] == '+' {
// Looks like a comment +line.
f := strings.Fields(string(line))
if f[0] == "+build" {
ok := false
for _, tok := range f[1:] {
if ctxt.match(tok) {
ok = true
break
}
}
if !ok {
return false // this one doesn't match
}
}
}
}
}
return true // everything matches
}
// saveCgo saves the information from the #cgo lines in the import "C" comment.
// These lines set CFLAGS and LDFLAGS and pkg-config directives that affect
// the way cgo's C code is built.
//
// TODO(rsc): This duplicates code in cgo.
// Once the dust settles, remove this code from cgo.
func (ctxt *Context) saveCgo(filename string, di *DirInfo, 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.match(c) {
ok = true
break
}
}
if !ok {
continue
}
}
args, err := splitQuoted(argstr)
if err != nil {
return fmt.Errorf("%s: invalid #cgo line: %s", filename, orig)
}
for _, arg := range args {
if !safeName(arg) {
return fmt.Errorf("%s: malformed #cgo argument: %s", filename, arg)
}
}
switch verb {
case "CFLAGS":
di.CgoCFLAGS = append(di.CgoCFLAGS, 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
}
var safeBytes = []byte("+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:")
func safeName(s string) bool {
if s == "" {
return false
}
for i := 0; i < len(s); i++ {
if c := s[i]; c < 0x80 && bytes.IndexByte(safeBytes, 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
}
// match returns true if the name is one of:
//
// $GOOS
// $GOARCH
// cgo (if cgo is enabled)
// !cgo (if cgo is disabled)
// tag (if tag is listed in ctxt.BuildTags)
// !tag (if tag is not listed in ctxt.BuildTags)
// a slash-separated list of any of these
//
func (ctxt *Context) match(name string) bool {
if name == "" {
return false
}
if i := strings.Index(name, ","); i >= 0 {
// comma-separated list
return ctxt.match(name[:i]) && ctxt.match(name[i+1:])
}
if strings.HasPrefix(name, "!!") { // bad syntax, reject always
return false
}
if strings.HasPrefix(name, "!") { // negation
return !ctxt.match(name[1:])
}
// Tags must be letters, digits, underscores.
// Unlike in Go identifiers, all digits is fine (e.g., "386").
for _, c := range name {
if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' {
return false
}
}
// special tags
if ctxt.CgoEnabled && name == "cgo" {
return true
}
if name == ctxt.GOOS || name == ctxt.GOARCH {
return true
}
// other tags
for _, tag := range ctxt.BuildTags {
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.*
//
func (ctxt *Context) goodOSArchFile(name string) bool {
if dot := strings.Index(name, "."); dot != -1 {
name = name[:dot]
}
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 l[n-2] == ctxt.GOOS && l[n-1] == ctxt.GOARCH
}
if n >= 1 && knownOS[l[n-1]] {
return l[n-1] == ctxt.GOOS
}
if n >= 1 && knownArch[l[n-1]] {
return l[n-1] == ctxt.GOARCH
}
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
}
}
src/pkg/go/build/path.go
View file @ 38a03de6
......@@ -12,9 +12,6 @@ import (
"runtime"
)
// ToolDir is the directory containing build tools.
var ToolDir = filepath.Join(runtime.GOROOT(), "pkg/tool/"+runtime.GOOS+"_"+runtime.GOARCH)
// Path is a validated list of Trees derived from $GOROOT and $GOPATH at init.
var Path []*Tree
......@@ -128,16 +125,6 @@ func FindTree(path string) (tree *Tree, pkg string, err error) {
return
}
// isLocalPath returns whether the given path is local (/foo ./foo ../foo . ..)
// Windows paths that starts with drive letter (c:\foo c:foo) are considered local.
func isLocalPath(s string) bool {
const sep = string(filepath.Separator)
return s == "." || s == ".." ||
filepath.HasPrefix(s, sep) ||
filepath.HasPrefix(s, "."+sep) || filepath.HasPrefix(s, ".."+sep) ||
filepath.VolumeName(s) != ""
}
var (
// argument lists used by the build's gc and ld methods
gcImportArgs []string
......
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