R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5570056

        In order to allow buildscript.sh to generate buildscripts for all
        $GOOS/$GOARCH combinations, we have to generate dummy files for cmd/go.
        Fixes #2586.

R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/5557050

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5574056

Fixes #2759.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5570053

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5575049

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5569054

R=rsc, imkrasin
CC=golang-dev
https://golang.org/cl/5569048

Also, add an explicit error type when the right hand side is an unexported
function.

R=golang-dev, gri, rogpeppe, agl, rsc
CC=golang-dev
https://golang.org/cl/5564048

Fixes #2700.

R=rsc
CC=golang-dev
https://golang.org/cl/5574046

Includes gofix module. The only case not covered should be
xml.Unmarshal, since it remains with a similar interface, and
would require introspecting the type of its first argument
better.

Fixes #2626.

R=golang-dev, rsc, gustavo
CC=golang-dev
https://golang.org/cl/5574053

CL 5572043 removed the last uses of this field.
The information is readily available from Type.Decl.

R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/5570049

R=nigeltao, christoph, rsc, r, tux21b
CC=golang-dev
https://golang.org/cl/5573048

Also: remove an unused template variable declaration.

R=adg
CC=golang-dev
https://golang.org/cl/5572043

The bitLen function currently shifts out blocks of 8 bits at a time.
This change replaces this sorta-linear algorithm with a log(N)
one (shift out 16 bits, then 8, then 4, then 2, then 1).
I left the start of it linear at 16 bits at a time so that
the function continues to work with 32 or 64 bit values
without any funkiness.
The algorithm is similar to several of the nlz ("number of
leading zeros") algorithms from "Hacker's Delight" or the
"bit twiddling hacks" pages.

Doesn't make a big difference to the existing benchmarks, but
I'm using the code in a different context that calls bitLen
much more often, so it seemed worthwhile making the existing
codebase faster so that it's a better building block.

Microbenchmark results on a 64-bit Macbook Pro using 6g from weekly.2012-01-20:

benchmark                old ns/op    new ns/op    delta
big.BenchmarkBitLen0             4            6  +50.12%
big.BenchmarkBitLen1             4            6  +33.91%
big.BenchmarkBitLen2             6            6   +3.05%
big.BenchmarkBitLen3             7            6  -19.05%
big.BenchmarkBitLen4             9            6  -30.19%
big.BenchmarkBitLen5            11            6  -42.23%
big.BenchmarkBitLen8            16            6  -61.78%
big.BenchmarkBitLen9             5            6  +18.29%
big.BenchmarkBitLen16           18            7  -60.99%
big.BenchmarkBitLen17            7            6   -4.64%
big.BenchmarkBitLen31           19            7  -62.49%

On an ARM machine (with the previous weekly):

benchmark                old ns/op    new ns/op    delta
big.BenchmarkBitLen0            37           50  +36.56%
big.BenchmarkBitLen1            59           51  -13.69%
big.BenchmarkBitLen2            74           59  -20.40%
big.BenchmarkBitLen3            92           60  -34.89%
big.BenchmarkBitLen4           110           59  -46.09%
big.BenchmarkBitLen5           127           60  -52.68%
big.BenchmarkBitLen8           181           59  -67.24%
big.BenchmarkBitLen9            78           60  -23.05%
big.BenchmarkBitLen16          199           69  -65.13%
big.BenchmarkBitLen17           91           70  -23.17%
big.BenchmarkBitLen31          210           95  -54.43%

R=golang-dev, dave, edsrzf, gri
CC=golang-dev
https://golang.org/cl/5570044

This avoids the need for a custom Makefile.

R=gri
CC=golang-dev
https://golang.org/cl/5575045

TBR=r
CC=golang-dev
https://golang.org/cl/5571050

Move error information into Package struct, so that
a package can be returned even if a dependency failed
to load or did not exist.  This makes it possible to run
'go fix' or 'go fmt' on packages with broken dependencies
or missing imports.  It also enables go get -fix.
The new go list -e flag lets go list process those package
errors as normal data.

Change p.Doc to be first sentence of package doc, not
entire package doc.  Makes go list -json or
go list -f '{{.ImportPath}} {{.Doc}}' much more reasonable.

The go tool now depends on http, which means also
net and crypto/tls, both of which use cgo.  Trying to
make the build scripts that build the go tool understand
and handle cgo is too much work.  Instead, we build
a stripped down version of the go tool, compiled as go_bootstrap,
that substitutes an error stub for the usual HTTP code.
The buildscript builds go_bootstrap, go_bootstrap builds
the standard packages and commands, including the full
including-HTTP-support go tool, and then go_bootstrap
gets deleted.

Also handle the case where the buildscript needs updating
during all.bash: if it fails but a go command can be found on
the current $PATH, try to regenerate it.  This gracefully
handles situations like adding a new file to a package
used by the go tool.

R=r, adg
CC=golang-dev
https://golang.org/cl/5553059

This lets the client of go/build specify additional tags that
can be recognized in a // +build directive.  For example,
a build for a custom environment like App Engine might
include "appengine" in the BuildTags list, so that packages
can be written with some files saying

        // +build appengine   (build only on app engine)

or

        // +build !appengine  (build only when NOT on app engine)

App Engine here is just a hypothetical context.  I plan to use
this in the cmd/go sources to distinguish the bootstrap version
of cmd/go (which will not use networking) from the full version
using a custom tag.  It might also be useful in App Engine.

Also, delete Build and Script, which we did not end up using for
cmd/go and which never got turned on for real in goinstall.

R=r, adg
CC=golang-dev
https://golang.org/cl/5554079

R=ken2
CC=golang-dev
https://golang.org/cl/5573047

        Fixes #2454.

R=rsc, mikioh.mikioh, golang-dev, iant, iant
CC=golang-dev
https://golang.org/cl/5557068

Golden files have extension .d.golden where d is the mode value (0 or 1 for now)
(i.e., testdata/file.out is now testdata/file.0.golden, and there is a new file
testdata/file.1.golden for each testcase)

R=rsc
CC=golang-dev
https://golang.org/cl/5573046

for map iteration.  New code makes table output predictable and fixes
bug.

R=rsc, r
CC=golang-dev
https://golang.org/cl/5573044

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5562047

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5571046

Google contributor.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/5554084

So it's not included in the package by the go tool.

R=iant, fullung, rsc
CC=golang-dev
https://golang.org/cl/5563049

Document that indirection through a nil pointer will panic.
Explain function invocation.
This section will need more work, but it's a start.

Fixes #1865.
Fixes #2252.

R=rsc, iant, r
CC=golang-dev
https://golang.org/cl/5532114

R=adg, rsc, r
CC=golang-dev
https://golang.org/cl/5562051

Fixes #2674.

R=rsc
CC=golang-dev
https://golang.org/cl/5574045

Fixes #2582

R=rsc
CC=golang-dev
https://golang.org/cl/5574044

R=rsc
CC=golang-dev
https://golang.org/cl/5555071

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5561060

R=rsc, nigeltao
CC=golang-dev
https://golang.org/cl/5561056

R=rsc
CC=golang-dev
https://golang.org/cl/5555070

iant's idea.

Fixes #2745.

R=iant, dsymonds
CC=golang-dev
https://golang.org/cl/5536085

Invaluable when changing template files.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5571044

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5564045

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5564046

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5571043

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5569043