obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

1 files changed, 620 insertions, 0 deletions

diff --git a/libgo/go/compress/flate/inflate.go b/libgo/go/compress/flate/inflate.go
new file mode 100644
index 000000000..7dc8cf93b
--- /dev/null
+++ b/libgo/go/compress/flate/inflate.go
@@ -0,0 +1,620 @@
+// 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.
+
+// The flate package implements the DEFLATE compressed data
+// format, described in RFC 1951.  The gzip and zlib packages
+// implement access to DEFLATE-based file formats.
+package flate
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"strconv"
+)
+
+const (
+	maxCodeLen = 16    // max length of Huffman code
+	maxHist    = 32768 // max history required
+	maxLit     = 286
+	maxDist    = 32
+	numCodes   = 19 // number of codes in Huffman meta-code
+)
+
+// A CorruptInputError reports the presence of corrupt input at a given offset.
+type CorruptInputError int64
+
+func (e CorruptInputError) String() string {
+	return "flate: corrupt input before offset " + strconv.Itoa64(int64(e))
+}
+
+// An InternalError reports an error in the flate code itself.
+type InternalError string
+
+func (e InternalError) String() string { return "flate: internal error: " + string(e) }
+
+// A ReadError reports an error encountered while reading input.
+type ReadError struct {
+	Offset int64    // byte offset where error occurred
+	Error  os.Error // error returned by underlying Read
+}
+
+func (e *ReadError) String() string {
+	return "flate: read error at offset " + strconv.Itoa64(e.Offset) + ": " + e.Error.String()
+}
+
+// A WriteError reports an error encountered while writing output.
+type WriteError struct {
+	Offset int64    // byte offset where error occurred
+	Error  os.Error // error returned by underlying Write
+}
+
+func (e *WriteError) String() string {
+	return "flate: write error at offset " + strconv.Itoa64(e.Offset) + ": " + e.Error.String()
+}
+
+// Huffman decoder is based on
+// J. Brian Connell, ``A Huffman-Shannon-Fano Code,''
+// Proceedings of the IEEE, 61(7) (July 1973), pp 1046-1047.
+type huffmanDecoder struct {
+	// min, max code length
+	min, max int
+
+	// limit[i] = largest code word of length i
+	// Given code v of length n,
+	// need more bits if v > limit[n].
+	limit [maxCodeLen + 1]int
+
+	// base[i] = smallest code word of length i - seq number
+	base [maxCodeLen + 1]int
+
+	// codes[seq number] = output code.
+	// Given code v of length n, value is
+	// codes[v - base[n]].
+	codes []int
+}
+
+// Initialize Huffman decoding tables from array of code lengths.
+func (h *huffmanDecoder) init(bits []int) bool {
+	// TODO(rsc): Return false sometimes.
+
+	// Count number of codes of each length,
+	// compute min and max length.
+	var count [maxCodeLen + 1]int
+	var min, max int
+	for _, n := range bits {
+		if n == 0 {
+			continue
+		}
+		if min == 0 || n < min {
+			min = n
+		}
+		if n > max {
+			max = n
+		}
+		count[n]++
+	}
+	if max == 0 {
+		return false
+	}
+
+	h.min = min
+	h.max = max
+
+	// For each code range, compute
+	// nextcode (first code of that length),
+	// limit (last code of that length), and
+	// base (offset from first code to sequence number).
+	code := 0
+	seq := 0
+	var nextcode [maxCodeLen]int
+	for i := min; i <= max; i++ {
+		n := count[i]
+		nextcode[i] = code
+		h.base[i] = code - seq
+		code += n
+		seq += n
+		h.limit[i] = code - 1
+		code <<= 1
+	}
+
+	// Make array mapping sequence numbers to codes.
+	if len(h.codes) < len(bits) {
+		h.codes = make([]int, len(bits))
+	}
+	for i, n := range bits {
+		if n == 0 {
+			continue
+		}
+		code := nextcode[n]
+		nextcode[n]++
+		seq := code - h.base[n]
+		h.codes[seq] = i
+	}
+	return true
+}
+
+// Hard-coded Huffman tables for DEFLATE algorithm.
+// See RFC 1951, section 3.2.6.
+var fixedHuffmanDecoder = huffmanDecoder{
+	7, 9,
+	[maxCodeLen + 1]int{7: 23, 199, 511},
+	[maxCodeLen + 1]int{7: 0, 24, 224},
+	[]int{
+		// length 7: 256-279
+		256, 257, 258, 259, 260, 261, 262,
+		263, 264, 265, 266, 267, 268, 269,
+		270, 271, 272, 273, 274, 275, 276,
+		277, 278, 279,
+
+		// length 8: 0-143
+		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
+		12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
+		22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+		32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
+		42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
+		52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
+		62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
+		72, 73, 74, 75, 76, 77, 78, 79, 80, 81,
+		82, 83, 84, 85, 86, 87, 88, 89, 90, 91,
+		92, 93, 94, 95, 96, 97, 98, 99, 100,
+		101, 102, 103, 104, 105, 106, 107, 108,
+		109, 110, 111, 112, 113, 114, 115, 116,
+		117, 118, 119, 120, 121, 122, 123, 124,
+		125, 126, 127, 128, 129, 130, 131, 132,
+		133, 134, 135, 136, 137, 138, 139, 140,
+		141, 142, 143,
+
+		// length 8: 280-287
+		280, 281, 282, 283, 284, 285, 286, 287,
+
+		// length 9: 144-255
+		144, 145, 146, 147, 148, 149, 150, 151,
+		152, 153, 154, 155, 156, 157, 158, 159,
+		160, 161, 162, 163, 164, 165, 166, 167,
+		168, 169, 170, 171, 172, 173, 174, 175,
+		176, 177, 178, 179, 180, 181, 182, 183,
+		184, 185, 186, 187, 188, 189, 190, 191,
+		192, 193, 194, 195, 196, 197, 198, 199,
+		200, 201, 202, 203, 204, 205, 206, 207,
+		208, 209, 210, 211, 212, 213, 214, 215,
+		216, 217, 218, 219, 220, 221, 222, 223,
+		224, 225, 226, 227, 228, 229, 230, 231,
+		232, 233, 234, 235, 236, 237, 238, 239,
+		240, 241, 242, 243, 244, 245, 246, 247,
+		248, 249, 250, 251, 252, 253, 254, 255,
+	},
+}
+
+// The actual read interface needed by NewReader.
+// If the passed in io.Reader does not also have ReadByte,
+// the NewReader will introduce its own buffering.
+type Reader interface {
+	io.Reader
+	ReadByte() (c byte, err os.Error)
+}
+
+// Decompress state.
+type decompressor struct {
+	// Input/output sources.
+	r       Reader
+	w       io.Writer
+	roffset int64
+	woffset int64
+
+	// Input bits, in top of b.
+	b  uint32
+	nb uint
+
+	// Huffman decoders for literal/length, distance.
+	h1, h2 huffmanDecoder
+
+	// Length arrays used to define Huffman codes.
+	bits     [maxLit + maxDist]int
+	codebits [numCodes]int
+
+	// Output history, buffer.
+	hist  [maxHist]byte
+	hp    int  // current output position in buffer
+	hw    int  // have written hist[0:hw] already
+	hfull bool // buffer has filled at least once
+
+	// Temporary buffer (avoids repeated allocation).
+	buf [4]byte
+}
+
+func (f *decompressor) inflate() (err os.Error) {
+	final := false
+	for err == nil && !final {
+		for f.nb < 1+2 {
+			if err = f.moreBits(); err != nil {
+				return
+			}
+		}
+		final = f.b&1 == 1
+		f.b >>= 1
+		typ := f.b & 3
+		f.b >>= 2
+		f.nb -= 1 + 2
+		switch typ {
+		case 0:
+			err = f.dataBlock()
+		case 1:
+			// compressed, fixed Huffman tables
+			err = f.decodeBlock(&fixedHuffmanDecoder, nil)
+		case 2:
+			// compressed, dynamic Huffman tables
+			if err = f.readHuffman(); err == nil {
+				err = f.decodeBlock(&f.h1, &f.h2)
+			}
+		default:
+			// 3 is reserved.
+			err = CorruptInputError(f.roffset)
+		}
+	}
+	return
+}
+
+// RFC 1951 section 3.2.7.
+// Compression with dynamic Huffman codes
+
+var codeOrder = [...]int{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}
+
+func (f *decompressor) readHuffman() os.Error {
+	// HLIT[5], HDIST[5], HCLEN[4].
+	for f.nb < 5+5+4 {
+		if err := f.moreBits(); err != nil {
+			return err
+		}
+	}
+	nlit := int(f.b&0x1F) + 257
+	f.b >>= 5
+	ndist := int(f.b&0x1F) + 1
+	f.b >>= 5
+	nclen := int(f.b&0xF) + 4
+	f.b >>= 4
+	f.nb -= 5 + 5 + 4
+
+	// (HCLEN+4)*3 bits: code lengths in the magic codeOrder order.
+	for i := 0; i < nclen; i++ {
+		for f.nb < 3 {
+			if err := f.moreBits(); err != nil {
+				return err
+			}
+		}
+		f.codebits[codeOrder[i]] = int(f.b & 0x7)
+		f.b >>= 3
+		f.nb -= 3
+	}
+	for i := nclen; i < len(codeOrder); i++ {
+		f.codebits[codeOrder[i]] = 0
+	}
+	if !f.h1.init(f.codebits[0:]) {
+		return CorruptInputError(f.roffset)
+	}
+
+	// HLIT + 257 code lengths, HDIST + 1 code lengths,
+	// using the code length Huffman code.
+	for i, n := 0, nlit+ndist; i < n; {
+		x, err := f.huffSym(&f.h1)
+		if err != nil {
+			return err
+		}
+		if x < 16 {
+			// Actual length.
+			f.bits[i] = x
+			i++
+			continue
+		}
+		// Repeat previous length or zero.
+		var rep int
+		var nb uint
+		var b int
+		switch x {
+		default:
+			return InternalError("unexpected length code")
+		case 16:
+			rep = 3
+			nb = 2
+			if i == 0 {
+				return CorruptInputError(f.roffset)
+			}
+			b = f.bits[i-1]
+		case 17:
+			rep = 3
+			nb = 3
+			b = 0
+		case 18:
+			rep = 11
+			nb = 7
+			b = 0
+		}
+		for f.nb < nb {
+			if err := f.moreBits(); err != nil {
+				return err
+			}
+		}
+		rep += int(f.b & uint32(1<<nb-1))
+		f.b >>= nb
+		f.nb -= nb
+		if i+rep > n {
+			return CorruptInputError(f.roffset)
+		}
+		for j := 0; j < rep; j++ {
+			f.bits[i] = b
+			i++
+		}
+	}
+
+	if !f.h1.init(f.bits[0:nlit]) || !f.h2.init(f.bits[nlit:nlit+ndist]) {
+		return CorruptInputError(f.roffset)
+	}
+
+	return nil
+}
+
+// Decode a single Huffman block from f.
+// hl and hd are the Huffman states for the lit/length values
+// and the distance values, respectively.  If hd == nil, using the
+// fixed distance encoding associated with fixed Huffman blocks.
+func (f *decompressor) decodeBlock(hl, hd *huffmanDecoder) os.Error {
+	for {
+		v, err := f.huffSym(hl)
+		if err != nil {
+			return err
+		}
+		var n uint // number of bits extra
+		var length int
+		switch {
+		case v < 256:
+			f.hist[f.hp] = byte(v)
+			f.hp++
+			if f.hp == len(f.hist) {
+				if err = f.flush(); err != nil {
+					return err
+				}
+			}
+			continue
+		case v == 256:
+			return nil
+		// otherwise, reference to older data
+		case v < 265:
+			length = v - (257 - 3)
+			n = 0
+		case v < 269:
+			length = v*2 - (265*2 - 11)
+			n = 1
+		case v < 273:
+			length = v*4 - (269*4 - 19)
+			n = 2
+		case v < 277:
+			length = v*8 - (273*8 - 35)
+			n = 3
+		case v < 281:
+			length = v*16 - (277*16 - 67)
+			n = 4
+		case v < 285:
+			length = v*32 - (281*32 - 131)
+			n = 5
+		default:
+			length = 258
+			n = 0
+		}
+		if n > 0 {
+			for f.nb < n {
+				if err = f.moreBits(); err != nil {
+					return err
+				}
+			}
+			length += int(f.b & uint32(1<<n-1))
+			f.b >>= n
+			f.nb -= n
+		}
+
+		var dist int
+		if hd == nil {
+			for f.nb < 5 {
+				if err = f.moreBits(); err != nil {
+					return err
+				}
+			}
+			dist = int(reverseByte[(f.b&0x1F)<<3])
+			f.b >>= 5
+			f.nb -= 5
+		} else {
+			if dist, err = f.huffSym(hd); err != nil {
+				return err
+			}
+		}
+
+		switch {
+		case dist < 4:
+			dist++
+		case dist >= 30:
+			return CorruptInputError(f.roffset)
+		default:
+			nb := uint(dist-2) >> 1
+			// have 1 bit in bottom of dist, need nb more.
+			extra := (dist & 1) << nb
+			for f.nb < nb {
+				if err = f.moreBits(); err != nil {
+					return err
+				}
+			}
+			extra |= int(f.b & uint32(1<<nb-1))
+			f.b >>= nb
+			f.nb -= nb
+			dist = 1<<(nb+1) + 1 + extra
+		}
+
+		// Copy history[-dist:-dist+length] into output.
+		if dist > len(f.hist) {
+			return InternalError("bad history distance")
+		}
+
+		// No check on length; encoding can be prescient.
+		if !f.hfull && dist > f.hp {
+			return CorruptInputError(f.roffset)
+		}
+
+		p := f.hp - dist
+		if p < 0 {
+			p += len(f.hist)
+		}
+		for i := 0; i < length; i++ {
+			f.hist[f.hp] = f.hist[p]
+			f.hp++
+			p++
+			if f.hp == len(f.hist) {
+				if err = f.flush(); err != nil {
+					return err
+				}
+			}
+			if p == len(f.hist) {
+				p = 0
+			}
+		}
+	}
+	panic("unreached")
+}
+
+// Copy a single uncompressed data block from input to output.
+func (f *decompressor) dataBlock() os.Error {
+	// Uncompressed.
+	// Discard current half-byte.
+	f.nb = 0
+	f.b = 0
+
+	// Length then ones-complement of length.
+	nr, err := io.ReadFull(f.r, f.buf[0:4])
+	f.roffset += int64(nr)
+	if err != nil {
+		return &ReadError{f.roffset, err}
+	}
+	n := int(f.buf[0]) | int(f.buf[1])<<8
+	nn := int(f.buf[2]) | int(f.buf[3])<<8
+	if uint16(nn) != uint16(^n) {
+		return CorruptInputError(f.roffset)
+	}
+
+	if n == 0 {
+		// 0-length block means sync
+		return f.flush()
+	}
+
+	// Read len bytes into history,
+	// writing as history fills.
+	for n > 0 {
+		m := len(f.hist) - f.hp
+		if m > n {
+			m = n
+		}
+		m, err := io.ReadFull(f.r, f.hist[f.hp:f.hp+m])
+		f.roffset += int64(m)
+		if err != nil {
+			return &ReadError{f.roffset, err}
+		}
+		n -= m
+		f.hp += m
+		if f.hp == len(f.hist) {
+			if err = f.flush(); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (f *decompressor) moreBits() os.Error {
+	c, err := f.r.ReadByte()
+	if err != nil {
+		if err == os.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return err
+	}
+	f.roffset++
+	f.b |= uint32(c) << f.nb
+	f.nb += 8
+	return nil
+}
+
+// Read the next Huffman-encoded symbol from f according to h.
+func (f *decompressor) huffSym(h *huffmanDecoder) (int, os.Error) {
+	for n := uint(h.min); n <= uint(h.max); n++ {
+		lim := h.limit[n]
+		if lim == -1 {
+			continue
+		}
+		for f.nb < n {
+			if err := f.moreBits(); err != nil {
+				return 0, err
+			}
+		}
+		v := int(f.b & uint32(1<<n-1))
+		v <<= 16 - n
+		v = int(reverseByte[v>>8]) | int(reverseByte[v&0xFF])<<8 // reverse bits
+		if v <= lim {
+			f.b >>= n
+			f.nb -= n
+			return h.codes[v-h.base[n]], nil
+		}
+	}
+	return 0, CorruptInputError(f.roffset)
+}
+
+// Flush any buffered output to the underlying writer.
+func (f *decompressor) flush() os.Error {
+	if f.hw == f.hp {
+		return nil
+	}
+	n, err := f.w.Write(f.hist[f.hw:f.hp])
+	if n != f.hp-f.hw && err == nil {
+		err = io.ErrShortWrite
+	}
+	if err != nil {
+		return &WriteError{f.woffset, err}
+	}
+	f.woffset += int64(f.hp - f.hw)
+	f.hw = f.hp
+	if f.hp == len(f.hist) {
+		f.hp = 0
+		f.hw = 0
+		f.hfull = true
+	}
+	return nil
+}
+
+func makeReader(r io.Reader) Reader {
+	if rr, ok := r.(Reader); ok {
+		return rr
+	}
+	return bufio.NewReader(r)
+}
+
+// decompress reads DEFLATE-compressed data from r and writes
+// the uncompressed data to w.
+func (f *decompressor) decompress(r io.Reader, w io.Writer) os.Error {
+	f.r = makeReader(r)
+	f.w = w
+	f.woffset = 0
+	if err := f.inflate(); err != nil {
+		return err
+	}
+	if err := f.flush(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// NewReader returns a new ReadCloser that can be used
+// to read the uncompressed version of r.  It is the caller's
+// responsibility to call Close on the ReadCloser when
+// finished reading.
+func NewReader(r io.Reader) io.ReadCloser {
+	var f decompressor
+	pr, pw := io.Pipe()
+	go func() { pw.CloseWithError(f.decompress(r, pw)) }()
+	return pr
+}