Fixes #7638

LGTM=rsc
R=rsc, adg, robert.hencke, bradfitz
CC=golang-codereviews
https://golang.org/cl/89280043

The code cannot have worked before, because it was
trying to use the old value in a range check for the new
type, which might have a different representation
(hence the 'internal compiler error').

Fixes #8073.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/98630045

fixes #8047

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/101800043

Fixes #7863

LGTM=rsc
R=rsc, ruiu
CC=golang-codereviews
https://golang.org/cl/98610045

Common mistake (at least for me) because hg etc. require the prefix
while the go command forbids it.

Before:
% go get http://code.google.com/p/go.text/unicode/norm
package http:/code.google.com/p/go.text/unicode/norm: unrecognized import path "http:/code.google.com/p/go.text/unicode/norm"

After:
% go get http://code.google.com/p/go.text/unicode/norm
package http:/code.google.com/p/go.text/unicode/norm: "http://" not allowed in import path

LGTM=ruiu, rsc
R=rsc, ruiu
CC=golang-codereviews
https://golang.org/cl/97630046

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/99440046

Update #8083

See discussion in https://groups.google.com/forum/#!topic/golang-dev/dh6Ra_xJomc

LGTM=khr
R=golang-codereviews, gobot, khr
CC=golang-codereviews
https://golang.org/cl/99440048

when deleting from a nil map.  See issue 8051.

LGTM=r
R=golang-codereviews, r, khr
CC=golang-codereviews
https://golang.org/cl/96540051

Fixes #6720.

LGTM=bradfitz
R=golang-codereviews, iant, bradfitz
CC=golang-codereviews
https://golang.org/cl/92340043

The spec was unclear about whether blank methods should be
permitted in interface types. gccgo permits at most one, gc
crashes if there are more than one, go/types permits at most
one.

Discussion:

Since method sets of non-interface types never contain methods
with blank names (blank methods are never declared), it is impossible
to satisfy an interface with a blank method.

It is possible to declare variables of assignable interface types
(but not necessarily identical types) containing blank methods, and
assign those variables to each other, but the values of those
variables can only be nil.

There appear to be two "reasonable" alternatives:

1) Permit at most one blank method (since method names must be unique),
and consider it part of the interface. This is what appears to happen
now, with corner-case bugs. Such interfaces can never be implemented.

2) Permit arbitrary many blank methods but ignore them. This appears
to be closer to the handling of blank identifiers in declarations.
However, an interface type literal is not a declaration (it's a type
literal). Also, for struct types, blank identifiers are not ignored;
so the analogy with declarations is flawed.

Both these alternatives don't seem to add any benefit and are likely
(if only slightly) more complicated to explain and implement than
disallowing blank methods in interfaces altogether.

Fixes #6604.

LGTM=r, rsc, iant
R=r, rsc, ken, iant
CC=golang-codereviews
https://golang.org/cl/99410046

The key property here is what the bit pattern represents,
not what its type is. Storing 5 into a pointer is the problem.
Storing a uintptr that holds pointer bits back into a pointer
is not as much of a problem, and not what we are claiming
the runtime will detect.

Longer discussion at
https://groups.google.com/d/msg/golang-nuts/dIGISmr9hw0/0jO4ce85Eh0J

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/98370045

This is a quick documentation change/clarification, as this
confused me before: in my own cgo-based projects, I currently have
identical #cgo directives in each relevant source file, and I notice
with go build -x that cgo is combining the directives, leading to
pkg-config invocations with the same package name (gtk+-3.0, in my
case) repeated several times, or on Mac OS X, LDFLAGS listing
-framework Foundation -framework AppKit multiple times. Since I am
about to add a CFLAGS as well, I checked the source to cmd/cgo and
go/build (where the work is actually done) to see if that still holds
true there. Hopefully other people who have made the same mistake I
have (I don't know if anyone has) can remove the excess declarations
now; this should make things slightly easier to manage as well.

LGTM=iant
R=golang-codereviews, gobot, iant
CC=golang-codereviews
https://golang.org/cl/91520046

Generated by addca.

R=gobot
CC=golang-codereviews
https://golang.org/cl/97660043

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/98460045

Update #8030

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/100620045

Ignore symbols that aren't text, data, or bss since they cause
problems when dissassembling instructions with small immediate
values.

Before:
        build.go:142    0x10ee  83ec50      SUBL $text/template/parse.autotmp_1293(SB), SP

After:
        build.go:142    0x10ee  83ec50      SUBL $0x50, SP

Fixes #7947.

LGTM=rsc
R=rsc, 0intro
CC=golang-codereviews
https://golang.org/cl/93520045

Noted by gri in CL 100660044 review but I missed them.

TBR=gri
CC=golang-codereviews
https://golang.org/cl/97570049

Add larger comment explaining testing methodology,
and derive tests arithmetically.

(These tests are checking rounding again; the derived
tests they replace were checking exact values.)

LGTM=r, gri
R=gri, r
CC=golang-codereviews
https://golang.org/cl/100660044

Passes the expanded test in CL 100660044,
which gives me some confidence that it
might be right.

(The old code failed by not considering all the
low bits.)

LGTM=r
R=golang-codereviews, r, bradfitz
CC=golang-codereviews, iant, khr
https://golang.org/cl/99410051

Rewrite formatFloat to be much simpler and clearer and
avoid the tricky interaction with padding.
The issue refers to complex but the problem is just floating-point.
The new tests added were incorrectly formatted before this fix.
Fixes #8064.

LGTM=jscrockett01, rsc
R=rsc, jscrockett01
CC=golang-codereviews
https://golang.org/cl/99420048

Fixes #8062.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/91610046

Fixes #7983.

LGTM=crawshaw
R=golang-codereviews, crawshaw
CC=golang-codereviews, rsc
https://golang.org/cl/96540044

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/95480045

These constants pass go/types constant conversions as well.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/91590047

Fixes #8061.

LGTM=crawshaw
R=golang-codereviews, crawshaw
CC=golang-codereviews
https://golang.org/cl/93520046

Patch from http://gnats.NetBSD.org/48811.

LGTM=iant
R=golang-codereviews, minux.ma, iant
CC=golang-codereviews, tk
https://golang.org/cl/94670047

Fixes #8032.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/95580043

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/100660043

The spec did not specify the order in which
init() functions are called. Specify that
they are called in source order since we have
now also specified the initialization order
of independent variables.

While technically a language change, no
existing code could have relied on this,
so this should not break anything.

Per suggestion from rsc.

LGTM=r, iant
R=rsc, iant, r, ken
CC=golang-codereviews
https://golang.org/cl/98420046

Fixes #8051

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/95560046

- split description of package initialization and
  program execution
- better grouping of concerns in section on package
  initialization
- more explicit definition of what constitues a
  dependency
- removed language about constant dependencies -
  they are computed at compile-time and not
  initialized at run-time
- clarified that independent variables are initialized
  in declaration order (rather than reference order)

Note that the last clarification is what distinguishes
gc and gccgo at the moment: gc uses reference order
(i.e., order in which variables are referenced in
initialization expressions), while gccgo uses declaration
order for independent variables.

Not a language change. But adopting this CL will
clarify what constitutes a dependency.

Fixes #6703.

LGTM=adonovan, r, iant, rsc
R=r, rsc, iant, ken, adonovan
CC=golang-codereviews
https://golang.org/cl/99020043

LGTM=gri
R=gri
CC=golang-codereviews
https://golang.org/cl/99420045

LGTM=minux.ma
R=adg, minux.ma
CC=golang-codereviews
https://golang.org/cl/95540045

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/93470043

Fixes #7701. (again, differently)

LGTM=rsc
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/94560043

TBR=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/98480043

This idea was rejected in CL 5731059. We should fix the
runtime docs instead.

««« original CL description
cmd/dist: reflect local changes to tree in goversion

runtime.Version() requires a trailing "+" when
tree had local modifications at time of build.

Fixes #7701

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/84040045

»»»

LGTM=rsc, mra
R=iant, rsc, mra
CC=golang-codereviews
https://golang.org/cl/100520043

- Don't export Prog structure.
- Remove ProgHeader and ExecTable structures.
- Add Magic, Bss and Entry fields in FileHeader.
- Replace ?_MAGIC variables with constants.
- Ignore final EOF from ReadAt.
- Improve documentation.

Fixes #7989.

LGTM=rsc
R=rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/91400044

Explain which files the go command looks at, and what they represent.
Fixes #6348.

LGTM=rsc
R=rsc, minux.ma
CC=golang-codereviews
https://golang.org/cl/96480043

Fixes #7958.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/91590044