Add Go frontend, libgo library, and Go testsuite.

gcc/:
	* gcc.c (default_compilers): Add entry for ".go".
	* common.opt: Add -static-libgo as a driver option.
	* doc/install.texi (Configuration): Mention libgo as an option for
	--enable-shared.  Mention go as an option for --enable-languages.
	* doc/invoke.texi (Overall Options): Mention .go as a file name
	suffix.  Mention go as a -x option.
	* doc/frontends.texi (G++ and GCC): Mention Go as a supported
	language.
	* doc/sourcebuild.texi (Top Level): Mention libgo.
	* doc/standards.texi (Standards): Add section on Go language.
	Move references for other languages into their own section.
	* doc/contrib.texi (Contributors): Mention that I contributed the
	Go frontend.
gcc/testsuite/:
	* lib/go.exp: New file.
	* lib/go-dg.exp: New file.
	* lib/go-torture.exp: New file.
	* lib/target-supports.exp (check_compile): Match // Go.

From-SVN: r167407

1 files changed, 693 insertions, 0 deletions

diff --git a/libgo/go/http/request.go b/libgo/go/http/request.go
new file mode 100644
index 0000000..b886899
--- /dev/null
+++ b/libgo/go/http/request.go
@@ -0,0 +1,693 @@
+// Copyright 2009 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.
+
+// HTTP Request reading and parsing.
+
+// The http package implements parsing of HTTP requests, replies,
+// and URLs and provides an extensible HTTP server and a basic
+// HTTP client.
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"container/vector"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime"
+	"mime/multipart"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	maxLineLength  = 4096 // assumed <= bufio.defaultBufSize
+	maxValueLength = 4096
+	maxHeaderLines = 1024
+	chunkSize      = 4 << 10 // 4 KB chunks
+)
+
+// HTTP request parsing errors.
+type ProtocolError struct {
+	os.ErrorString
+}
+
+var (
+	ErrLineTooLong          = &ProtocolError{"header line too long"}
+	ErrHeaderTooLong        = &ProtocolError{"header too long"}
+	ErrShortBody            = &ProtocolError{"entity body too short"}
+	ErrNotSupported         = &ProtocolError{"feature not supported"}
+	ErrUnexpectedTrailer    = &ProtocolError{"trailer header without chunked transfer encoding"}
+	ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"}
+	ErrNotMultipart         = &ProtocolError{"request Content-Type isn't multipart/form-data"}
+	ErrMissingBoundary      = &ProtocolError{"no multipart boundary param Content-Type"}
+)
+
+type badStringError struct {
+	what string
+	str  string
+}
+
+func (e *badStringError) String() string { return fmt.Sprintf("%s %q", e.what, e.str) }
+
+var reqExcludeHeader = map[string]bool{
+	"Host":              true,
+	"User-Agent":        true,
+	"Referer":           true,
+	"Content-Length":    true,
+	"Transfer-Encoding": true,
+	"Trailer":           true,
+}
+
+// A Request represents a parsed HTTP request header.
+type Request struct {
+	Method     string // GET, POST, PUT, etc.
+	RawURL     string // The raw URL given in the request.
+	URL        *URL   // Parsed URL.
+	Proto      string // "HTTP/1.0"
+	ProtoMajor int    // 1
+	ProtoMinor int    // 0
+
+	// A header maps request lines to their values.
+	// If the header says
+	//
+	//	accept-encoding: gzip, deflate
+	//	Accept-Language: en-us
+	//	Connection: keep-alive
+	//
+	// then
+	//
+	//	Header = map[string]string{
+	//		"Accept-Encoding": "gzip, deflate",
+	//		"Accept-Language": "en-us",
+	//		"Connection": "keep-alive",
+	//	}
+	//
+	// HTTP defines that header names are case-insensitive.
+	// The request parser implements this by canonicalizing the
+	// name, making the first character and any characters
+	// following a hyphen uppercase and the rest lowercase.
+	Header map[string]string
+
+	// The message body.
+	Body io.ReadCloser
+
+	// ContentLength records the length of the associated content.
+	// The value -1 indicates that the length is unknown.
+	// Values >= 0 indicate that the given number of bytes may be read from Body.
+	ContentLength int64
+
+	// TransferEncoding lists the transfer encodings from outermost to innermost.
+	// An empty list denotes the "identity" encoding.
+	TransferEncoding []string
+
+	// Whether to close the connection after replying to this request.
+	Close bool
+
+	// The host on which the URL is sought.
+	// Per RFC 2616, this is either the value of the Host: header
+	// or the host name given in the URL itself.
+	Host string
+
+	// The referring URL, if sent in the request.
+	//
+	// Referer is misspelled as in the request itself,
+	// a mistake from the earliest days of HTTP.
+	// This value can also be fetched from the Header map
+	// as Header["Referer"]; the benefit of making it
+	// available as a structure field is that the compiler
+	// can diagnose programs that use the alternate
+	// (correct English) spelling req.Referrer but cannot
+	// diagnose programs that use Header["Referrer"].
+	Referer string
+
+	// The User-Agent: header string, if sent in the request.
+	UserAgent string
+
+	// The parsed form. Only available after ParseForm is called.
+	Form map[string][]string
+
+	// Trailer maps trailer keys to values.  Like for Header, if the
+	// response has multiple trailer lines with the same key, they will be
+	// concatenated, delimited by commas.
+	Trailer map[string]string
+}
+
+// ProtoAtLeast returns whether the HTTP protocol used
+// in the request is at least major.minor.
+func (r *Request) ProtoAtLeast(major, minor int) bool {
+	return r.ProtoMajor > major ||
+		r.ProtoMajor == major && r.ProtoMinor >= minor
+}
+
+// MultipartReader returns a MIME multipart reader if this is a
+// multipart/form-data POST request, else returns nil and an error.
+func (r *Request) MultipartReader() (multipart.Reader, os.Error) {
+	v, ok := r.Header["Content-Type"]
+	if !ok {
+		return nil, ErrNotMultipart
+	}
+	d, params := mime.ParseMediaType(v)
+	if d != "multipart/form-data" {
+		return nil, ErrNotMultipart
+	}
+	boundary, ok := params["boundary"]
+	if !ok {
+		return nil, ErrMissingBoundary
+	}
+	return multipart.NewReader(r.Body, boundary), nil
+}
+
+// Return value if nonempty, def otherwise.
+func valueOrDefault(value, def string) string {
+	if value != "" {
+		return value
+	}
+	return def
+}
+
+const defaultUserAgent = "Go http package"
+
+// Write writes an HTTP/1.1 request -- header and body -- in wire format.
+// This method consults the following fields of req:
+//	Host
+//	RawURL, if non-empty, or else URL
+//	Method (defaults to "GET")
+//	UserAgent (defaults to defaultUserAgent)
+//	Referer
+//	Header
+//	Body
+//
+// If Body is present, Write forces "Transfer-Encoding: chunked" as a header
+// and then closes Body when finished sending it.
+func (req *Request) Write(w io.Writer) os.Error {
+	host := req.Host
+	if host == "" {
+		host = req.URL.Host
+	}
+
+	uri := req.RawURL
+	if uri == "" {
+		uri = valueOrDefault(urlEscape(req.URL.Path, encodePath), "/")
+		if req.URL.RawQuery != "" {
+			uri += "?" + req.URL.RawQuery
+		}
+	}
+
+	fmt.Fprintf(w, "%s %s HTTP/1.1\r\n", valueOrDefault(req.Method, "GET"), uri)
+
+	// Header lines
+	fmt.Fprintf(w, "Host: %s\r\n", host)
+	fmt.Fprintf(w, "User-Agent: %s\r\n", valueOrDefault(req.UserAgent, defaultUserAgent))
+	if req.Referer != "" {
+		fmt.Fprintf(w, "Referer: %s\r\n", req.Referer)
+	}
+
+	// Process Body,ContentLength,Close,Trailer
+	tw, err := newTransferWriter(req)
+	if err != nil {
+		return err
+	}
+	err = tw.WriteHeader(w)
+	if err != nil {
+		return err
+	}
+
+	// TODO: split long values?  (If so, should share code with Conn.Write)
+	// TODO: if Header includes values for Host, User-Agent, or Referer, this
+	// may conflict with the User-Agent or Referer headers we add manually.
+	// One solution would be to remove the Host, UserAgent, and Referer fields
+	// from Request, and introduce Request methods along the lines of
+	// Response.{GetHeader,AddHeader} and string constants for "Host",
+	// "User-Agent" and "Referer".
+	err = writeSortedKeyValue(w, req.Header, reqExcludeHeader)
+	if err != nil {
+		return err
+	}
+
+	io.WriteString(w, "\r\n")
+
+	// Write body and trailer
+	err = tw.WriteBody(w)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Read a line of bytes (up to \n) from b.
+// Give up if the line exceeds maxLineLength.
+// The returned bytes are a pointer into storage in
+// the bufio, so they are only valid until the next bufio read.
+func readLineBytes(b *bufio.Reader) (p []byte, err os.Error) {
+	if p, err = b.ReadSlice('\n'); err != nil {
+		// We always know when EOF is coming.
+		// If the caller asked for a line, there should be a line.
+		if err == os.EOF {
+			err = io.ErrUnexpectedEOF
+		} else if err == bufio.ErrBufferFull {
+			err = ErrLineTooLong
+		}
+		return nil, err
+	}
+	if len(p) >= maxLineLength {
+		return nil, ErrLineTooLong
+	}
+
+	// Chop off trailing white space.
+	var i int
+	for i = len(p); i > 0; i-- {
+		if c := p[i-1]; c != ' ' && c != '\r' && c != '\t' && c != '\n' {
+			break
+		}
+	}
+	return p[0:i], nil
+}
+
+// readLineBytes, but convert the bytes into a string.
+func readLine(b *bufio.Reader) (s string, err os.Error) {
+	p, e := readLineBytes(b)
+	if e != nil {
+		return "", e
+	}
+	return string(p), nil
+}
+
+var colon = []byte{':'}
+
+// Read a key/value pair from b.
+// A key/value has the form Key: Value\r\n
+// and the Value can continue on multiple lines if each continuation line
+// starts with a space.
+func readKeyValue(b *bufio.Reader) (key, value string, err os.Error) {
+	line, e := readLineBytes(b)
+	if e != nil {
+		return "", "", e
+	}
+	if len(line) == 0 {
+		return "", "", nil
+	}
+
+	// Scan first line for colon.
+	i := bytes.Index(line, colon)
+	if i < 0 {
+		goto Malformed
+	}
+
+	key = string(line[0:i])
+	if strings.Contains(key, " ") {
+		// Key field has space - no good.
+		goto Malformed
+	}
+
+	// Skip initial space before value.
+	for i++; i < len(line); i++ {
+		if line[i] != ' ' {
+			break
+		}
+	}
+	value = string(line[i:])
+
+	// Look for extension lines, which must begin with space.
+	for {
+		c, e := b.ReadByte()
+		if c != ' ' {
+			if e != os.EOF {
+				b.UnreadByte()
+			}
+			break
+		}
+
+		// Eat leading space.
+		for c == ' ' {
+			if c, e = b.ReadByte(); e != nil {
+				if e == os.EOF {
+					e = io.ErrUnexpectedEOF
+				}
+				return "", "", e
+			}
+		}
+		b.UnreadByte()
+
+		// Read the rest of the line and add to value.
+		if line, e = readLineBytes(b); e != nil {
+			return "", "", e
+		}
+		value += " " + string(line)
+
+		if len(value) >= maxValueLength {
+			return "", "", &badStringError{"value too long for key", key}
+		}
+	}
+	return key, value, nil
+
+Malformed:
+	return "", "", &badStringError{"malformed header line", string(line)}
+}
+
+// Convert decimal at s[i:len(s)] to integer,
+// returning value, string position where the digits stopped,
+// and whether there was a valid number (digits, not too big).
+func atoi(s string, i int) (n, i1 int, ok bool) {
+	const Big = 1000000
+	if i >= len(s) || s[i] < '0' || s[i] > '9' {
+		return 0, 0, false
+	}
+	n = 0
+	for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+		n = n*10 + int(s[i]-'0')
+		if n > Big {
+			return 0, 0, false
+		}
+	}
+	return n, i, true
+}
+
+// Parse HTTP version: "HTTP/1.2" -> (1, 2, true).
+func parseHTTPVersion(vers string) (int, int, bool) {
+	if len(vers) < 5 || vers[0:5] != "HTTP/" {
+		return 0, 0, false
+	}
+	major, i, ok := atoi(vers, 5)
+	if !ok || i >= len(vers) || vers[i] != '.' {
+		return 0, 0, false
+	}
+	var minor int
+	minor, i, ok = atoi(vers, i+1)
+	if !ok || i != len(vers) {
+		return 0, 0, false
+	}
+	return major, minor, true
+}
+
+// CanonicalHeaderKey returns the canonical format of the
+// HTTP header key s.  The canonicalization converts the first
+// letter and any letter following a hyphen to upper case;
+// the rest are converted to lowercase.  For example, the
+// canonical key for "accept-encoding" is "Accept-Encoding".
+func CanonicalHeaderKey(s string) string {
+	// canonicalize: first letter upper case
+	// and upper case after each dash.
+	// (Host, User-Agent, If-Modified-Since).
+	// HTTP headers are ASCII only, so no Unicode issues.
+	var a []byte
+	upper := true
+	for i := 0; i < len(s); i++ {
+		v := s[i]
+		if upper && 'a' <= v && v <= 'z' {
+			if a == nil {
+				a = []byte(s)
+			}
+			a[i] = v + 'A' - 'a'
+		}
+		if !upper && 'A' <= v && v <= 'Z' {
+			if a == nil {
+				a = []byte(s)
+			}
+			a[i] = v + 'a' - 'A'
+		}
+		upper = false
+		if v == '-' {
+			upper = true
+		}
+	}
+	if a != nil {
+		return string(a)
+	}
+	return s
+}
+
+type chunkedReader struct {
+	r   *bufio.Reader
+	n   uint64 // unread bytes in chunk
+	err os.Error
+}
+
+func newChunkedReader(r *bufio.Reader) *chunkedReader {
+	return &chunkedReader{r: r}
+}
+
+func (cr *chunkedReader) beginChunk() {
+	// chunk-size CRLF
+	var line string
+	line, cr.err = readLine(cr.r)
+	if cr.err != nil {
+		return
+	}
+	cr.n, cr.err = strconv.Btoui64(line, 16)
+	if cr.err != nil {
+		return
+	}
+	if cr.n == 0 {
+		// trailer CRLF
+		for {
+			line, cr.err = readLine(cr.r)
+			if cr.err != nil {
+				return
+			}
+			if line == "" {
+				break
+			}
+		}
+		cr.err = os.EOF
+	}
+}
+
+func (cr *chunkedReader) Read(b []uint8) (n int, err os.Error) {
+	if cr.err != nil {
+		return 0, cr.err
+	}
+	if cr.n == 0 {
+		cr.beginChunk()
+		if cr.err != nil {
+			return 0, cr.err
+		}
+	}
+	if uint64(len(b)) > cr.n {
+		b = b[0:cr.n]
+	}
+	n, cr.err = cr.r.Read(b)
+	cr.n -= uint64(n)
+	if cr.n == 0 && cr.err == nil {
+		// end of chunk (CRLF)
+		b := make([]byte, 2)
+		if _, cr.err = io.ReadFull(cr.r, b); cr.err == nil {
+			if b[0] != '\r' || b[1] != '\n' {
+				cr.err = os.NewError("malformed chunked encoding")
+			}
+		}
+	}
+	return n, cr.err
+}
+
+// ReadRequest reads and parses a request from b.
+func ReadRequest(b *bufio.Reader) (req *Request, err os.Error) {
+	req = new(Request)
+
+	// First line: GET /index.html HTTP/1.0
+	var s string
+	if s, err = readLine(b); err != nil {
+		return nil, err
+	}
+
+	var f []string
+	if f = strings.Split(s, " ", 3); len(f) < 3 {
+		return nil, &badStringError{"malformed HTTP request", s}
+	}
+	req.Method, req.RawURL, req.Proto = f[0], f[1], f[2]
+	var ok bool
+	if req.ProtoMajor, req.ProtoMinor, ok = parseHTTPVersion(req.Proto); !ok {
+		return nil, &badStringError{"malformed HTTP version", req.Proto}
+	}
+
+	if req.URL, err = ParseURL(req.RawURL); err != nil {
+		return nil, err
+	}
+
+	// Subsequent lines: Key: value.
+	nheader := 0
+	req.Header = make(map[string]string)
+	for {
+		var key, value string
+		if key, value, err = readKeyValue(b); err != nil {
+			return nil, err
+		}
+		if key == "" {
+			break
+		}
+		if nheader++; nheader >= maxHeaderLines {
+			return nil, ErrHeaderTooLong
+		}
+
+		key = CanonicalHeaderKey(key)
+
+		// RFC 2616 says that if you send the same header key
+		// multiple times, it has to be semantically equivalent
+		// to concatenating the values separated by commas.
+		oldvalue, present := req.Header[key]
+		if present {
+			req.Header[key] = oldvalue + "," + value
+		} else {
+			req.Header[key] = value
+		}
+	}
+
+	// RFC2616: Must treat
+	//	GET /index.html HTTP/1.1
+	//	Host: www.google.com
+	// and
+	//	GET http://www.google.com/index.html HTTP/1.1
+	//	Host: doesntmatter
+	// the same.  In the second case, any Host line is ignored.
+	req.Host = req.URL.Host
+	if req.Host == "" {
+		req.Host = req.Header["Host"]
+	}
+	req.Header["Host"] = "", false
+
+	fixPragmaCacheControl(req.Header)
+
+	// Pull out useful fields as a convenience to clients.
+	req.Referer = req.Header["Referer"]
+	req.Header["Referer"] = "", false
+
+	req.UserAgent = req.Header["User-Agent"]
+	req.Header["User-Agent"] = "", false
+
+	// TODO: Parse specific header values:
+	//	Accept
+	//	Accept-Encoding
+	//	Accept-Language
+	//	Authorization
+	//	Cache-Control
+	//	Connection
+	//	Date
+	//	Expect
+	//	From
+	//	If-Match
+	//	If-Modified-Since
+	//	If-None-Match
+	//	If-Range
+	//	If-Unmodified-Since
+	//	Max-Forwards
+	//	Proxy-Authorization
+	//	Referer [sic]
+	//	TE (transfer-codings)
+	//	Trailer
+	//	Transfer-Encoding
+	//	Upgrade
+	//	User-Agent
+	//	Via
+	//	Warning
+
+	err = readTransfer(req, b)
+	if err != nil {
+		return nil, err
+	}
+
+	return req, nil
+}
+
+// ParseQuery parses the URL-encoded query string and returns
+// a map listing the values specified for each key.
+// ParseQuery always returns a non-nil map containing all the
+// valid query parameters found; err describes the first decoding error
+// encountered, if any.
+func ParseQuery(query string) (m map[string][]string, err os.Error) {
+	m = make(map[string][]string)
+	err = parseQuery(m, query)
+	return
+}
+
+func parseQuery(m map[string][]string, query string) (err os.Error) {
+	for _, kv := range strings.Split(query, "&", -1) {
+		if len(kv) == 0 {
+			continue
+		}
+		kvPair := strings.Split(kv, "=", 2)
+
+		var key, value string
+		var e os.Error
+		key, e = URLUnescape(kvPair[0])
+		if e == nil && len(kvPair) > 1 {
+			value, e = URLUnescape(kvPair[1])
+		}
+		if e != nil {
+			err = e
+			continue
+		}
+		vec := vector.StringVector(m[key])
+		vec.Push(value)
+		m[key] = vec
+	}
+	return err
+}
+
+// ParseForm parses the request body as a form for POST requests, or the raw query for GET requests.
+// It is idempotent.
+func (r *Request) ParseForm() (err os.Error) {
+	if r.Form != nil {
+		return
+	}
+
+	r.Form = make(map[string][]string)
+	if r.URL != nil {
+		err = parseQuery(r.Form, r.URL.RawQuery)
+	}
+	if r.Method == "POST" {
+		if r.Body == nil {
+			return os.ErrorString("missing form body")
+		}
+		ct := r.Header["Content-Type"]
+		switch strings.Split(ct, ";", 2)[0] {
+		case "text/plain", "application/x-www-form-urlencoded", "":
+			b, e := ioutil.ReadAll(r.Body)
+			if e != nil {
+				if err == nil {
+					err = e
+				}
+				break
+			}
+			e = parseQuery(r.Form, string(b))
+			if err == nil {
+				err = e
+			}
+		// TODO(dsymonds): Handle multipart/form-data
+		default:
+			return &badStringError{"unknown Content-Type", ct}
+		}
+	}
+	return err
+}
+
+// FormValue returns the first value for the named component of the query.
+// FormValue calls ParseForm if necessary.
+func (r *Request) FormValue(key string) string {
+	if r.Form == nil {
+		r.ParseForm()
+	}
+	if vs := r.Form[key]; len(vs) > 0 {
+		return vs[0]
+	}
+	return ""
+}
+
+func (r *Request) expectsContinue() bool {
+	expectation, ok := r.Header["Expect"]
+	return ok && strings.ToLower(expectation) == "100-continue"
+}
+
+func (r *Request) wantsHttp10KeepAlive() bool {
+	if r.ProtoMajor != 1 || r.ProtoMinor != 0 {
+		return false
+	}
+	value, exists := r.Header["Connection"]
+	if !exists {
+		return false
+	}
+	return strings.Contains(strings.ToLower(value), "keep-alive")
+}