In a testing situation, it's possible for a local http
server to panic and the test exit without the stack trace
ever being printed.
Fixes#2480.
R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/5414048
This will be nicer to the automatic tools.
It requires a few more assembly stubs
but fewer Go files.
There are a few instances where it looks like
there are new blobs of code, but they are just
being copied out of deleted files.
There is no new code here.
Suppose you have a portable implementation for Sin
and a 386-specific assembly one. The old way to
do this was to write three files
sin_decl.go
func Sin(x float64) float64 // declaration only
sin_386.s
assembly implementation
sin_port.go
func Sin(x float64) float64 { ... } // pure-Go impl
and then link in either sin_decl.go+sin_386.s or
just sin_port.go. The Makefile actually did the magic
of linking in only the _port.go files for those without
assembly and only the _decl.go files for those with
assembly, or at least some of that magic.
The biggest problem with this, beyond being hard
to explain to the build system, is that once you do
explain it to the build system, godoc knows which
of sin_port.go or sin_decl.go are involved on a given
architecture, and it (correctly) ignores the other.
That means you have to put identical doc comments
in both files.
The new approach, which is more like what we did
in the later packages math/big and sync/atomic,
is to have
sin.go
func Sin(x float64) float64 // decl only
func sin(x float64) float64 {...} // pure-Go impl
sin_386.s
// assembly for Sin (ignores sin)
sin_amd64.s
// assembly for Sin: jmp sin
sin_arm.s
// assembly for Sin: jmp sin
Once we abandon Makefiles we can put all the assembly
stubs in one source file, so the number of files will
actually go down.
Chris asked whether the branches cost anything.
Given that they are branching to pure-Go implementations
that are not typically known for their speed, the single
direct branch is not going to be noticeable. That is,
it's on the slow path.
An alternative would have been to preserve the old
"only write assembly files when there's an implementation"
and still have just one copy of the declaration of Sin
(and thus one doc comment) by doing:
sin.go
func Sin(x float64) float64 { return sin(x) }
sin_decl.go
func sin(x float64) float64 // declaration only
sin_386.s
// assembly for sin
sin_port.go
func sin(x float64) float64 { portable code }
In this version everyone would link in sin.go and
then either sin_decl.go+sin_386.s or sin_port.go.
This has an extra function call on all paths, including
the "fast path" to get to assembly, and it triples the
number of Go files involved compared to what I did
in this CL. On the other hand you don't have to
write assembly stubs. After starting down this path
I decided that the assembly stubs were the easier
approach.
As for generating the assembly stubs on the fly, much
of the goal here is to eliminate magic from the build
process, so that zero-configuration tools like goinstall
or the new go tool can handle this package.
R=golang-dev, r, cw, iant, r
CC=golang-dev
https://golang.org/cl/5488057
Example:
PACKAGE
package utf8
import "unicode/utf8"
Package utf8 implements functions and constants to support text
encoded in UTF-8. This package calls a Unicode character a rune for
brevity.
CONSTANTS
const (
RuneError = unicode.ReplacementChar // the "error" Rune or "replacement character".
RuneSelf = 0x80 // characters below Runeself are represented as themselves in a single byte.
UTFMax = 4 // maximum number of bytes of a UTF-8 encoded Unicode character.
)
Numbers fundamental to the encoding.
FUNCTIONS
func DecodeLastRune(p []byte) (r rune, size int)
DecodeLastRune unpacks the last UTF-8 encoding in p and returns the
rune and its width in bytes.
func DecodeLastRuneInString(s string) (r rune, size int)
DecodeLastRuneInString is like DecodeLastRune but its input is a
string.
func DecodeRune(p []byte) (r rune, size int)
DecodeRune unpacks the first UTF-8 encoding in p and returns the rune
and its width in bytes.
func DecodeRuneInString(s string) (r rune, size int)
DecodeRuneInString is like DecodeRune but its input is a string.
func EncodeRune(p []byte, r rune) int
EncodeRune writes into p (which must be large enough) the UTF-8
encoding of the rune. It returns the number of bytes written.
func FullRune(p []byte) bool
FullRune reports whether the bytes in p begin with a full UTF-8
encoding of a rune. An invalid encoding is considered a full Rune
since it will convert as a width-1 error rune.
func FullRuneInString(s string) bool
FullRuneInString is like FullRune but its input is a string.
func RuneCount(p []byte) int
RuneCount returns the number of runes in p. Erroneous and short
encodings are treated as single runes of width 1 byte.
func RuneCountInString(s string) (n int)
RuneCountInString is like RuneCount but its input is a string.
func RuneLen(r rune) int
RuneLen returns the number of bytes required to encode the rune.
func RuneStart(b byte) bool
RuneStart reports whether the byte could be the first byte of an
encoded rune. Second and subsequent bytes always have the top two
bits set to 10.
func Valid(p []byte) bool
Valid reports whether p consists entirely of valid UTF-8-encoded
runes.
func ValidString(s string) bool
ValidString reports whether s consists entirely of valid UTF-8-encoded
runes.
TYPES
type String struct {
// contains filtered or unexported fields
}
String wraps a regular string with a small structure that provides
more efficient indexing by code point index, as opposed to byte index.
Scanning incrementally forwards or backwards is O(1) per index
operation (although not as fast a range clause going forwards).
Random access is O(N) in the length of the string, but the overhead is
less than always scanning from the beginning. If the string is ASCII,
random access is O(1). Unlike the built-in string type, String has
internal mutable state and is not thread-safe.
func NewString(contents string) *String
NewString returns a new UTF-8 string with the provided contents.
func (s *String) At(i int) rune
At returns the rune with index i in the String. The sequence of runes
is the same as iterating over the contents with a "for range" clause.
func (s *String) Init(contents string) *String
Init initializes an existing String to hold the provided contents.
It returns a pointer to the initialized String.
func (s *String) IsASCII() bool
IsASCII returns a boolean indicating whether the String contains only
ASCII bytes.
func (s *String) RuneCount() int
RuneCount returns the number of runes (Unicode code points) in the
String.
func (s *String) Slice(i, j int) string
Slice returns the string sliced at rune positions [i:j].
func (s *String) String() string
String returns the contents of the String. This method also means the
String is directly printable by fmt.Print.
Fixes#2479.
R=golang-dev, dsymonds, mattn.jp, r, gri, r
CC=golang-dev
https://golang.org/cl/5472051
To allow these types as map keys, we must fill in
equal and hash functions in their algorithm tables.
Structs or arrays that are "just memory", like [2]int,
can and do continue to use the AMEM algorithm.
Structs or arrays that contain special values like
strings or interface values use generated functions
for both equal and hash.
The runtime helper func runtime.equal(t, x, y) bool handles
the general equality case for x == y and calls out to
the equal implementation in the algorithm table.
For short values (<= 4 struct fields or array elements),
the sequence of elementwise comparisons is inlined
instead of calling runtime.equal.
R=ken, mpimenov
CC=golang-dev
https://golang.org/cl/5451105
I had to move readFile into sys_$GOOS.go
since syscall.Open takes only two arguments
on Plan 9.
R=lucio.dere, rsc, alex.brainman
CC=golang-dev
https://golang.org/cl/5447061
Made te and td arrays into variables te0-3 and td0-3,
which improves performance from 7000ns/op to 5800.
R=rsc, rogpeppe, agl
CC=golang-dev
https://golang.org/cl/5449077
syscall_windows.go contains a small demo, which calls the obsolete
syscall.Errstr function.
R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/5475044
Acosh, Asinh, Atanh, Ceil, Floor, Trunc, Mod and Remainder affected. These changes add some non-finite arguments and results (and -0.0 results).
R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/5469046
Although FIPS 186-3 says that we should truncate the hashes, at least
one other library (libgcrypt) doesn't. This means that it's impossible
to interoperate with code using gcrypt if we enforce the truncation
inside of crypto/dsa.
This change shouldn't actually affect anything because nearly
everybody pairs DSA with SHA1, which doesn't need to be truncated in
either case.
R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/5471043
The values have been generated only for the i386 and amd64 architectures.
R=golang-dev, mikioh.mikioh, dsymonds
CC=bradfitz, dsymonds, golang-dev
https://golang.org/cl/5452060
