Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

proposal: spec: binary integer literals #19308

Closed
EddieRingle opened this issue Feb 27, 2017 · 91 comments
Closed

proposal: spec: binary integer literals #19308

EddieRingle opened this issue Feb 27, 2017 · 91 comments

Comments

@EddieRingle
Copy link

@EddieRingle EddieRingle commented Feb 27, 2017

Currently, Go supports octal and hexadecimal integer literals in addition to the standard decimal literals you'd expect. In an effort to round out this group, I propose adding binary integer literals as well. They would come in the form as a new prefix to integer literals: 0b or 0B.

Initial Disclaimer

This was my first dive into the Go source code and primarily a learning experience for me to get my feet wet submitting changes and what-not. That being said, I appreciate any and all criticism, comments, and suggestions.

The "Why": Prior Art

Binary literals exist or have appeared in mainstream languages as well, including:

All of the above cases have settled on a convention of using 0b or 0B to prefix binary literals, suggesting that this would be a fairly comfortable and sensible choice for Go as well, avoiding needless invention and providing similarity for programmers coming from these other aforementioned languages.

The "Why": Continued

I managed to find some earlier discussions relating to this, albeit this was after I had already implemented the feature and it has more to do with changing the octal syntax than specifically relating to binary literals. But #12711 (comment) from @griesemer does mention that "both the 'o' for octal and 'b' for binary notation were also discussed in the design of Go. It's simply not enough bang for the buck." However, I don't see this as a good argument against adding something so simple to the language. Especially considering the fact that nowadays more and more languages have adopted the syntax for binary literals, it seems the earlier Go design decisions might need to be looked at under new light.

Example usage

const (
    SOME_MASK   = 0b00001111
    SOME_FLAG_A = 0b00000001
    SOME_FLAG_B = 0b00000010
    SOME_FLAG_C = 0b00000100
    SOME_FLAG_D = 0b00001000
)

Implementation

As I stated this was more of a learning experience for me, I already have changes that implement this feature ready:

CL-37502 spec: specify syntax for binary integer literals
CL-37503 cmd/compile/internal/syntax: scan binary literals
CL-37504 go/scanner: scan binary integer literals
CL-37505 strconv: support parsing binary integer literals
CL-37506 test: extend int_lit with binary literal usages

@bradfitz bradfitz added this to the Proposal milestone Feb 27, 2017
@bradfitz bradfitz added the Proposal label Feb 27, 2017
@griesemer
Copy link
Contributor

@griesemer griesemer commented Feb 27, 2017

This has come up before. There is a significant amount of work involved in rolling this out, making the compiler and spec changes is trivial. But there's a lot of libraries that should also be made consistent (strconv, math/big, etc.).

If we make a change in this direction, it should be more thorough and support arbitrary bases. I am against this as is.

@EddieRingle
Copy link
Author

@EddieRingle EddieRingle commented Feb 27, 2017

@griesemer Yes, the changes I'm about to submit also modifies strconv (to my understanding, it's actually required to support this change).

@EddieRingle
Copy link
Author

@EddieRingle EddieRingle commented Feb 27, 2017

@griesemer I disagree however that any change should support arbitrary bases or otherwise no change be made at all. From prior reading, it sounds like that would be a good goal for Go2; this is simply polishing Go1 with syntax developers of other languages might expect when using Go. (i.e. Base-2 is a common enough case, probably more common than octal; base-14 or what-have-you is less-so.)

@gopherbot
Copy link

@gopherbot gopherbot commented Feb 27, 2017

CL https://golang.org/cl/37503 mentions this issue.

@gopherbot
Copy link

@gopherbot gopherbot commented Feb 27, 2017

CL https://golang.org/cl/37504 mentions this issue.

@gopherbot
Copy link

@gopherbot gopherbot commented Feb 27, 2017

CL https://golang.org/cl/37502 mentions this issue.

@gopherbot
Copy link

@gopherbot gopherbot commented Feb 27, 2017

CL https://golang.org/cl/37505 mentions this issue.

@gopherbot
Copy link

@gopherbot gopherbot commented Feb 27, 2017

CL https://golang.org/cl/37506 mentions this issue.

@ALTree
Copy link
Member

@ALTree ALTree commented Feb 27, 2017

However, I don't see this as a good argument against adding something so simple to the language.

It's not a particularly strong argument in favour of adding them, either.

IMHO you'll need to expand the "why" section explaining exactly what advantages supporting binary literals will bring to people writing go code.

I don't find them particularly useful; hex is a much more readable and compact format for literals that have a "bit-level meaning".

You gave an 'usage example', but it's not very compelling. I would write those constants using 0xfs and shifts for the others.

@griesemer
Copy link
Contributor

@griesemer griesemer commented Feb 27, 2017

@EddieRingle This proposal has not been discussed widely nor has it been accepted. Please do not spam us with code reviews. The Go Team has enough to do with work that's actually important.

It is clear to everybody that adding a simple feature to the language is trivial. It's also clear that plenty of people would like this feature (I myself would have liked it sometime). But that said, just because one can, is not an argument that one should. Any however small and simple addition to a language has long-term costs. If we accept this, it will become even more difficult in the future to have a more general mechanism, and we need to remain backward compatible.

Let's wait and see what other people say before jumping the gun. Thanks.

@bradfitz
Copy link
Contributor

@bradfitz bradfitz commented Feb 27, 2017

Reminder of our no-me-too policy: https://golang.org/wiki/NoMeToo

Opinions without constructive content can be expressed using Github's emoji reactions.

@EddieRingle
Copy link
Author

@EddieRingle EddieRingle commented Feb 27, 2017

@ALTree

IMHO you'll need to expand the "why" section explaining exactly what advantages supporting binary literals will bring to people writing go code.

I don't find them particularly useful; hex is a much more readable and compact format for literals that have a "bit-level meaning", IMO.

I'd argue the opposite, actually. Hex is more compact in many cases, yes, but binary literals would be an exact "bit-level" representation and therefore as readable as you could get.

@griesemer

This proposal has not been discussed widely nor has it been accepted. Please do not spam us with code reviews. The Go Team has enough to do with work that's actually important.

Apologies. It was originally a single change but since it seems like the Go policy is to break up commits based on the area of codebase affected, that's how I ended up splitting them up. I wasn't aware the bot would make individual comments here for every change. I wouldn't be so cold as to call it spamming you, however, nor imply that any effort I put in using my free time is unimportant.

Any however small and simple addition to a language has long-term costs. If we accept this, it will become even more difficult in the future to have a more general mechanism, and we need to remain backward compatible.

Like was mentioned before, the general-purpose route (which I would prefer, as well) would also encourage the deprecation/removal of the existing (confusing) octal syntax, no? The feeling I got was that the general-purpose syntax (2r0010 or 2x0010 for base-2, for example) was invention meant for Go2, where breaking changes would be welcome anyway.

Putting a potential Go2 aside, to address the statement that "if we accept this, it will become even more difficult in the future to have a more general mechanism": I just don't see how this is true. Adding the binary literal prefix would be orthogonal to an alternative, general-purpose syntax, especially the one you described in #12711 (in fact, that syntax conflicts directly with hexadecimal literals, but would not with this proposed binary literal syntax). They would exist side-by-side just as the general-purpose syntax would with the existing octal, hex, and decimal literals.

@cespare
Copy link
Contributor

@cespare cespare commented Feb 27, 2017

Apologies. It was originally a single change but since it seems like the Go policy is to break up commits based on the area of codebase affected, that's how I ended up splitting them up. I wasn't aware the bot would make individual comments here for every change. I wouldn't be so cold as to call it spamming you, however, nor imply that any effort I put in using my free time is unimportant.

It's not just that the bot sends mail about CLs, it's that each mailed CL is a request for a Go reviewer to spend time reviewing it.

@wedow
Copy link

@wedow wedow commented Feb 27, 2017

The 0b syntax is nice because it's familiar but if the true goal is simply to add binary literals to the language, I would much prefer the generic solution over the familiar.

Is there any technical reason the generic option can't be implemented prior to 2.0? I've had a number of cases lately where binary literals would have been preferred over hex and it would be nice to have that option in 1.9 or 1.10 instead of waiting (possibly many years) until 2.0.

@ianlancetaylor
Copy link
Contributor

@ianlancetaylor ianlancetaylor commented Feb 27, 2017

@wedow I think it would help to see specific real cases where binary literals are useful. Please share the cases where binary literals would be helpful. Thanks.

@dr2chase
Copy link
Contributor

@dr2chase dr2chase commented Feb 27, 2017

I don't see "should support arbitrary bases" as a worthwhile objection. It adds complexity/cost for little or not additional benefit. Over all the years I've been hacking, the would-be-useful bases I've heard of people wanting to use are 2, 8, 10, 12, and 16, and possibly 64 (we have base64 encoding, after all).

@rsc rsc changed the title proposal: Binary integer literals proposal: spec: binary integer literals Feb 27, 2017
@AndreasBackx
Copy link

@AndreasBackx AndreasBackx commented Feb 27, 2017

Let's look at why the aforementioned languages have moved forward and added support for binary literals. Let's start with C++14 as it is the first one on the list. What were the points James Dennett, then Google employee, brought forward?

Use of an 0b/0B prefix for binary literals is an existing GCC extension (also supported by Clang), and is the same syntax as Java 7, Python, and D.

Why would this particular point benefit Go?

Familiarity with the language.

Many developers move from programming language to programming language. Correct me if I'm wrong, but we all try what we know from one language in another one. You could in a way say that Go's familiarity with C and C++ attracted those kinds of developers who wanted a particular feature like GC, but didn't like other languages. This is one of the reason's the company I currently intern for has chosen to move to Go.

Besides experienced developers, let's also have a look what the benefit is of familiarity for beginner developers. Let's also take the use case of flags that @EddieRingle mentioned. Explaining to a complete beginner how flags work is a lot harder when you have to explain it in octal or hexadecimal as it requires the person to learn those as well.

Lastly I would like to add here that the purpose of every language (at least that's what I hope) is to write clean code. And I think that is something we all agree on regardless. When looking over someone else's code, it is immediately clear without any explanation that when having a list of binary literal constants, that those are flags. That same thing is a lot less straightforward when using hexadecimal or octal. Below is a comparison.

// Hexadecimal
const (
    MASK          = 0x1E
    DEFAULT_COLOR = 0x00
    BOLD          = 0x01
    UNDERLINE     = 0x02
    FLASHING_TEXT = 0x04
    NO_CHANGE     = 0x08
)

// Octal
const (
    MASK          = 036
    DEFAULT_COLOR = 00
    BOLD          = 01
    UNDERLINE     = 02
    FLASHING_TEXT = 04
    NO_CHANGE     = 010
)

// Binary
const (
    MASK          = 0b11110
    DEFAULT_COLOR = 0b00000
    BOLD          = 0b00001
    UNDERLINE     = 0b00010
    FLASHING_TEXT = 0b00100
    NO_CHANGE     = 0b01000
)

I do think that no thought needs to be given to the fact that the last constants are used for flags. These are also very few flags, so keep in mind that this definitely adds up when having more flags. The first constant 0x1E can definitely turn some heads when it's declared without context. Using binary literals alone may indicate that a variable might be used as a flag.

The referred C++ PDF further refers to the aforementioned languages for support. So let's look at those next. I have found the (original?) proposal by Derek Foster in 2009 for binary literals in JDK. Source

The first thing it questions, which I completely agree with, is why there is an octal representation in the JDK, but there is no binary representation in the JDK. In the past few years I have never thought to myself: "Oh, octals would make my code cleaner!" This however refers to the previous point I made: familiarity. There is one thing it however adds to my previously made point:

When the data being dealt with is fundamentally bit-oriented, however, using hexadecimal to represent ranges of bits requires an extra degree of translation for the programmer, and this can often become a source of errors. [...] then a programmer coding to that specification must translate each such value from its binary representation into hexadecimal. [...] In most cases, programmers do these translations in their heads, and HOPEFULLY get them right. however, errors can easily creep in, and re-verifying the results is not straightforward enough to be done frequently.

Hexadecimal and octal notation used primarily in hardware instead of binary can result in human errors. In the comparison I gave previously, I checked what I did with my head by entering what I thought was octal into Google which confirmed my answers. I am automatically sure of my case when I write it in binary, but am not when I write it in hexadecimal or octal. And no matter how many times you do this a day, it makes it harder to write code because you have to think of the binary form in your head and while doing so it is possible to make errors.

To dig deeper into the question to why there is an octal notation, but no binary notation I have another question to ask which was also asked by Derek Foster, the author of the binary literal proposal for the JDK: "Why did Go chose to use the 0 prefix for octal notations?" @griesemer commented that we should not jump the gun when implementing new features:

Let's wait and see what other people say before jumping the gun. Thanks.

But hasn't Go jumped the gun when implementing the octal notation? If its argument was "because other languages do it", then why can't that argument not be used for binary literals? If it wasn't, then what was the reason that the 0 prefix for octal notations made it into the language when it confuses people?

Someone might incorrectly think that "0b1" represented the same value as hexadecimal number "0xB1". However, note that this problem has existed for octal/decimal for many years (confusion between "050" and "50") and does not seem to be a major issue.

- Derek Foster

There don't seem to be more points in favour of binary literals because it is something we all refer to in our heads. This is why I feel proposals for other languages have been brief like this one. It however is not a reason to shut it down so quickly.

@randall77
Copy link
Contributor

@randall77 randall77 commented Feb 27, 2017

Here's another option, which seems clearer to me than any of the integer constants.

// Shifts
const (
    MASK          = 0x1e
    DEFAULT_COLOR = 0
    BOLD          = 1<<0
    UNDERLINE     = 1<<1
    FLASHING_TEXT = 1<<2
    NO_CHANGE     = 1<<3
)

(And shouldn't mask be 0xf, not 0x1e?)

I'm mildly against adding binary constants, at least in Go 1. I'd be for adding them in Go 2, though. The reason for the difference is that if for whatever reason someone is stuck at Go 1.8, when Go 1.9 comes out with binary constants, if one of the (transitive) imports of that person's code uses binary constants, then they can no longer build their project using Go 1.8. They would have to vendor or upgrade. There's a definite cost to adding a forward-incompatible feature which should weigh against its utility.

I do agree that I don't see any need for bases not in {2,8,10,16}. The case for octal seems particularly shaky, I'd be for removing octal in Go 2.

@AndreasBackx
Copy link

@AndreasBackx AndreasBackx commented Feb 27, 2017

@randall77 I disagree that shifting looks cleaner. In my head I'm still representing them as binary numbers and probably always will. It would make it easier to remove that calculation I do in my head.

(And shouldn't mask be 0xf, not 0x1e?)

The name MASK was merely taken from the JDK proposal and is not really in line with the other constants. But it does show that 0x1E and hexadecimals already cause confusion.

I can understand the point you're trying to make wanting to move it to Go 2. But I disagree that we should have to support projects that downgrade their Go version from 1.9 to 1.8. It would make languages changes a nightmare to deal with. I do however not know how Go looks at this, it would be most wise to follow what compatibility Go has in mind.

I wholeheartedly support your position on removing octal in Go 2.

@griesemer
Copy link
Contributor

@griesemer griesemer commented Feb 27, 2017

I just reread my previous comment (specifically, "The Go Team has enough to do with work that's actually important."). I want to apologize for this statement which was a rather offensive formulation of what I actually meant to say. So let me try again, elaborating a bit more and hopefully finding the right tone this time:

We do appreciate proposals that are well substantiated and, if necessary, come with prototype implementations. That said, the Go proposal process is light-weight on purpose, and no extra work is required by the proposer unless requested or necessary to understand the proposal. Sending change lists that are not requested and/or don't fix an issue is counter-productive since somebody will have to take the time and look at them (if only to postpone or close them). A better approach, if one does want to prototype/write the code ahead of time, is to link to the changes elsewhere (for instance, a private GitHub commit). This will leave the Go Team and external contributors the choice: They can decide to look at that code if they want to, or otherwise focus on higher-priority items. Thanks.

@EddieRingle
Copy link
Author

@EddieRingle EddieRingle commented Feb 27, 2017

@griesemer Gotcha, I understand and that makes sense. I assumed the Go team treated their Gerrit like AOSP does theirs, and figured my changes could exist there while this was discussed. Linking to a branch here on GitHub is less work anyway, so it's a win-win, I guess. :)

I actually did the work first since my main goal was to hack on the compiler. It was after the fact that I decided to submit it as a proposal.

@ianlancetaylor
Copy link
Contributor

@ianlancetaylor ianlancetaylor commented Feb 27, 2017

@AndreasBackx The leading 0 for octal in Go was discussed in issue #151. See also #12711.

@ALTree
Copy link
Member

@ALTree ALTree commented Feb 27, 2017

When defining 1-set-bit constants, shifting is more readable than 0b00001000..00 for the simple reason that in the shift version you don't need to count a bunch of zeros on the screen just to understand which bit is set; you just read the shift value.

0b100000000000000000000000 vs 1 << 23

@driusan
Copy link

@driusan driusan commented Feb 27, 2017

As far as real world usage goes, a common variable length integer encoding method is to use the high bit for "read more". I've had to use it to extract git packfiles. Here's the code to extract the lower bits in various bases:

b & 127
b & 0x1f
b & 0177
b & 0b01111111

I personally think that the binary version more clearly shows the intent.

@bamiaux
Copy link

@bamiaux bamiaux commented Feb 28, 2017

You still have the shift option mentioned previously
If you think it's not readable, use an helper function

b & ^(^0 << 7)
b & mask(7)
@RalphCorderoy
Copy link

@RalphCorderoy RalphCorderoy commented Feb 28, 2017

@AndreasBackx, 1<<12 is more clear than 0b0001000000000000 because I don't have to count all those zeroes. It's apparent it's a mask because the 12 falls between 11 and 13, or uses iota. When having to match an arbitrary pattern, e.g. masking bits from an instruction word, then hex is better because a programmer used to dealing with bits can read 0xae and "see" 10101110 by virtue of knowing 0xa, ten, is 1010, mnemonic ten-ten, just as one learns times tables, 65 is ASCII A, etc. Hex is a more dense representation that's easier to parse for the human reader.

@randall77, aren't 0644, 02775, etc., a bit tedious without octal? That's why it's still kicking about.

@randall77
Copy link
Contributor

@randall77 randall77 commented Feb 28, 2017

@RalphCorderoy : yes, it seems to me that octal survives for the sole reason of constructing an os.FileMode.
0664 = 6<<6 + 6<<3 + 4, which isn't too tedious. It would be better if os provided symbolic constants to make this easier, or at least clearer.

nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
This CL introduces go/scanner support for the new binary and octal integer
literals, hexadecimal floats, and digit separators for all number literals.
The new code is closely mirroring the respective code for number literals in
cmd/compile/internal/syntax/scanner.go.

R=Go1.13

Updates golang#12711.
Updates golang#19308.
Updates golang#28493.
Updates golang#29008.

Change-Id: I5315c6aaa7cfc41a618296be20e3acd5114d6b3c
Reviewed-on: https://go-review.googlesource.com/c/159997
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
R=Go1.13

Updates golang#12711.
Updates golang#19308.
Updates golang#28493.
Updates golang#29008.

Change-Id: Icd25aa7f6e18ed671ea6cf2b1b292899daf4b1a5
Reviewed-on: https://go-review.googlesource.com/c/160018
Reviewed-by: Russ Cox <rsc@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
This CL introduces go/constant support for the new binary and octal integer
literals, hexadecimal floats, and digit separators for all number literals.

R=Go1.13

Updates golang#12711.
Updates golang#19308.
Updates golang#28493.
Updates golang#29008.

Change-Id: I7a55f91b8b6373ae6d98ba923b626d33c5552946
Reviewed-on: https://go-review.googlesource.com/c/160239
Reviewed-by: Russ Cox <rsc@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
This CL ensures that go/types can now handle the new
Go 2 number literals. The relevant changes enabling
them in go/types were made in go/constant in the CL
https://golang.org/cl/160239.

R=Go1.13

Updates golang#12711.
Updates golang#19308.
Updates golang#28493.
Updates golang#29008.

Change-Id: I45c1387198fac94769ac59c5301d86b4e1a1ff98
Reviewed-on: https://go-review.googlesource.com/c/160240
Reviewed-by: Russ Cox <rsc@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
Rewrite non-decimal number prefixes to always use a lower-case base
("0X" -> "0x", etc.), and rewrite exponents to use a lower-case 'e'
or 'p'. Leave hexadecimal digits and 0-octals alone.

Comparing the best time of 3 runs of `time go test -run All` with
the time for a gofmt that doesn't do the rewrite shows no increase
in runtime for this bulk gofmt application (in fact on my machine
I see a small decline, probably due to cache effects).

R=Go1.13

Updates golang#12711.
Updates golang#19308.
Updates golang#29008.

Change-Id: I9c6ebed2ffa0a6a001c59412a73382090955f5a9
Reviewed-on: https://go-review.googlesource.com/c/160184
Reviewed-by: Ian Lance Taylor <iant@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
This CL introduces text/scanner support for the new binary and octal integer
literals, hexadecimal floats, and digit separators for all number literals.
The new code is closely mirroring the respective code for number literals in
cmd/compile/internal/syntax/scanner.go.

Uniformly use the term "invalid" rather than "illegal" in error messages
to match the respective error messages in the other scanners directly.

R=Go1.13

Updates golang#12711.
Updates golang#19308.
Updates golang#28493.
Updates golang#29008.

Change-Id: I2f291de13ba5afc0e530cd8326e6bf4c3858ebac
Reviewed-on: https://go-review.googlesource.com/c/161199
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 20, 2019
This CL modifies ParseInt and ParseUint to recognize
0b and 0o as binary and octal base prefixes when base == 0.

See golang.org/design/19308-number-literals for background.

For golang#19308.
For golang#12711.

Change-Id: I8efe067f415aa517bdefbff7e230d3fa1694d530
Reviewed-on: https://go-review.googlesource.com/c/160244
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
@gopherbot
Copy link

@gopherbot gopherbot commented Feb 20, 2019

Change https://golang.org/cl/163079 mentions this issue: text/scanner: don't liberally consume (invalid) floats or underbars

gopherbot pushed a commit that referenced this issue Feb 20, 2019
This is a follow-up on https://golang.org/cl/161199 which introduced
the new Go 2 number literals to text/scanner.

That change introduced a bug by allowing decimal and hexadecimal floats
to be consumed even if the scanner was not configured to accept floats.

This CL changes the code to not consume a radix dot '.' or exponent
unless the scanner is configured to accept floats.

This CL also introduces a new mode "AllowNumberbars" which controls
whether underbars '_' are permitted as digit separators in numbers
or not.

There is a possibility that we may need to refine text/scanner
further (e.g., the Float mode now includes hexadecimal floats
which it didn't recognize before). We're very early in the cycle,
so let's see how it goes.

RELNOTE=yes

Updates #12711.
Updates #19308.
Updates #28493.
Updates #29008.

Fixes #30320.

Change-Id: I6481d314f0384e09ef6803ffad38dc529b1e89a3
Reviewed-on: https://go-review.googlesource.com/c/163079
Reviewed-by: Ian Lance Taylor <iant@golang.org>
nebulabox added a commit to nebulabox/go that referenced this issue Feb 21, 2019
This is a follow-up on https://golang.org/cl/161199 which introduced
the new Go 2 number literals to text/scanner.

That change introduced a bug by allowing decimal and hexadecimal floats
to be consumed even if the scanner was not configured to accept floats.

This CL changes the code to not consume a radix dot '.' or exponent
unless the scanner is configured to accept floats.

This CL also introduces a new mode "AllowNumberbars" which controls
whether underbars '_' are permitted as digit separators in numbers
or not.

There is a possibility that we may need to refine text/scanner
further (e.g., the Float mode now includes hexadecimal floats
which it didn't recognize before). We're very early in the cycle,
so let's see how it goes.

RELNOTE=yes

Updates golang#12711.
Updates golang#19308.
Updates golang#28493.
Updates golang#29008.

Fixes golang#30320.

Change-Id: I6481d314f0384e09ef6803ffad38dc529b1e89a3
Reviewed-on: https://go-review.googlesource.com/c/163079
Reviewed-by: Ian Lance Taylor <iant@golang.org>
gopherbot pushed a commit that referenced this issue Feb 26, 2019
This CL modifies fmt's printer to implement %#b and %O
to emit leading 0b and 0o prefixes on binary and octal.
(%#o is already taken and emits "0377"; %O emits "0o377".)

See golang.org/design/19308-number-literals for background.

For #19308.
For #12711.
Vet update is #29986.

Change-Id: I7c38a4484c48a03abe9f6d45c7d981c7c314f583
Reviewed-on: https://go-review.googlesource.com/c/160246
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
gopherbot pushed a commit that referenced this issue Feb 26, 2019
This CL updates fmt's scanner to accept the new number syntaxes:

 - Hexadecimal floating-point values.
 - Digit-separating underscores.
 - Leading 0b and 0o prefixes.

See golang.org/design/19308-number-literals for background.

For #12711.
For #19308.
For #28493.
For #29008.

Change-Id: I5582af5c94059c781e6cf4e862441d3df3006adf
Reviewed-on: https://go-review.googlesource.com/c/160247
Reviewed-by: Robert Griesemer <gri@golang.org>
gopherbot pushed a commit that referenced this issue Feb 26, 2019
This CL updates text/template's scanner to accept the
new number syntaxes:

 - Hexadecimal floating-point values.
 - Digit-separating underscores.
 - Leading 0b and 0o prefixes.

See golang.org/design/19308-number-literals for background.

For #12711.
For #19308.
For #28493.
For #29008.

Change-Id: I68c16ea35c3f506701063781388de72bafee6b8d
Reviewed-on: https://go-review.googlesource.com/c/160248
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
gopherbot pushed a commit that referenced this issue Feb 26, 2019
Matching fmt, %#b now prints an 0b prefix,
and %O prints octal with an 0o prefix.

See golang.org/design/19308-number-literals for background.

For #19308.
For #12711.

Change-Id: I139c5a9a1dfae15415621601edfa13c6a5f19cfc
Reviewed-on: https://go-review.googlesource.com/c/160250
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
gopherbot pushed a commit that referenced this issue Mar 12, 2019
This CL documents the new binary and octal integer literals,
hexadecimal floats, generalized imaginary literals and digit
separators for all number literals in the spec.

Added empty lines between abutting paragraphs in some places
(a more thorough cleanup can be done in a separate CL).

A minor detail: A single 0 was considered an octal zero per the
syntax (decimal integer literals always started with a non-zero
digit). The new octal literal syntax allows 0o and 0O prefixes
and when keeping the respective octal_lit syntax symmetric with
all the others (binary_lit, hex_lit), a single 0 is not automatically
part of it anymore. Rather than complicating the new octal_lit syntax
to include 0 as before, it is simpler (and more natural) to accept
a single 0 as part of a decimal_lit. This is purely a notational
change.

R=Go1.13

Updates #12711.
Updates #19308.
Updates #28493.
Updates #29008.

Change-Id: Ib9fdc6e781f6031cceeed37aaed9d05c7141adec
Reviewed-on: https://go-review.googlesource.com/c/go/+/161098
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
@gopherbot
Copy link

@gopherbot gopherbot commented Apr 24, 2019

Change https://golang.org/cl/173663 mentions this issue: unicode/utf8: use binary literals

gopherbot pushed a commit that referenced this issue Apr 24, 2019
We were using hex literals and had the binary literal in a comment.
When I was working with this code, I always referred to the comment.
That's an indicator that we should just use the binary literal directly.

Updates #19308

Change-Id: I2279cb8efb4ae5f2e1558c15979058ab09eb4f6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/173663
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
@gopherbot
Copy link

@gopherbot gopherbot commented May 2, 2019

Change https://golang.org/cl/174897 mentions this issue: cmd/compile: disable Go1.13 language features for -lang=go1.12 and below

gopherbot pushed a commit that referenced this issue May 2, 2019
Fixes   #31747.
Updates #19308.
Updates #12711.
Updates #29008.
Updates #28493.
Updates #19113.

Change-Id: I76d2fdbc7698cc4e0f31b7ae24cbb4d28afbb6a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/174897
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
@rsc
Copy link
Contributor

@rsc rsc commented May 7, 2019

As a reminder, we introduced a new process for these Go 2-related language changes in our blog post blog.golang.org/go2-here-we-come. The Go 1.13 development cycle is now over and it’s time for the final decision.

The feedback on the Go 2 number literal changes has been strongly positive, with very few negative voices. These changes modernize and harmonize Go’s number literal syntax without adding significant complexity to the language: There is now a uniform prefix notation for the three common non-decimal number bases, which matches the notation used in other modern programming languages. The introduction of hexadecimal floating-point literals addresses a pain point for people concerning themselves with numeric code. The suffix “i” may now be used with any (non-imaginary) number literal to create an imaginary constant in a uniform way. And finally, underscores may be used to split longer literals into groups of digits for improved readability.

Proposal accepted for Go 1.13. Closing because the changes have landed.

- rsc for proposal review

@rsc rsc closed this May 7, 2019
Kiku-Reise added a commit to Kiku-Reise/go that referenced this issue May 16, 2019
fix (#1)
* cmd/compile: add unsigned divisibility rules

"Division by invariant integers using multiplication" paper
by Granlund and Montgomery contains a method for directly computing
divisibility (x%c == 0 for c constant) by means of the modular inverse.
The method is further elaborated in "Hacker's Delight" by Warren Section 10-17

This general rule can compute divisibilty by one multiplication and a compare
for odd divisors and an additional rotate for even divisors.

To apply the divisibility rule, we must take into account
the rules to rewrite x%c = x-((x/c)*c) and (x/c) for c constant on the first
optimization pass "opt".  This complicates the matching as we want to match
only in the cases where the result of (x/c) is not also available.
So, we must match on the expanded form of (x/c) in the expression x == c*(x/c)
in the "late opt" pass after common subexpresion elimination.

Note, that if there is an intermediate opt pass introduced in the future we
could simplify these rules by delaying the magic division rewrite to "late opt"
and matching directly on (x/c) in the intermediate opt pass.

Additional rules to lower the generic RotateLeft* ops were also applied.

On amd64, the divisibility check is 25-50% faster.

name                     old time/op  new time/op  delta
DivconstI64-4            2.08ns ± 0%  2.08ns ± 1%     ~     (p=0.881 n=5+5)
DivisibleconstI64-4      2.67ns ± 0%  2.67ns ± 1%     ~     (p=1.000 n=5+5)
DivisibleWDivconstI64-4  2.67ns ± 0%  2.67ns ± 0%     ~     (p=0.683 n=5+5)
DivconstU64-4            2.08ns ± 1%  2.08ns ± 1%     ~     (p=1.000 n=5+5)
DivisibleconstU64-4      2.77ns ± 1%  1.55ns ± 2%  -43.90%  (p=0.008 n=5+5)
DivisibleWDivconstU64-4  2.99ns ± 1%  2.99ns ± 1%     ~     (p=1.000 n=5+5)
DivconstI32-4            1.53ns ± 2%  1.53ns ± 0%     ~     (p=1.000 n=5+5)
DivisibleconstI32-4      2.23ns ± 0%  2.25ns ± 3%     ~     (p=0.167 n=5+5)
DivisibleWDivconstI32-4  2.27ns ± 1%  2.27ns ± 1%     ~     (p=0.429 n=5+5)
DivconstU32-4            1.78ns ± 0%  1.78ns ± 1%     ~     (p=1.000 n=4+5)
DivisibleconstU32-4      2.52ns ± 2%  1.26ns ± 0%  -49.96%  (p=0.000 n=5+4)
DivisibleWDivconstU32-4  2.63ns ± 0%  2.85ns ±10%   +8.29%  (p=0.016 n=4+5)
DivconstI16-4            1.54ns ± 0%  1.54ns ± 0%     ~     (p=0.333 n=4+5)
DivisibleconstI16-4      2.10ns ± 0%  2.10ns ± 1%     ~     (p=0.571 n=4+5)
DivisibleWDivconstI16-4  2.22ns ± 0%  2.23ns ± 1%     ~     (p=0.556 n=4+5)
DivconstU16-4            1.09ns ± 0%  1.01ns ± 1%   -7.74%  (p=0.000 n=4+5)
DivisibleconstU16-4      1.83ns ± 0%  1.26ns ± 0%  -31.52%  (p=0.008 n=5+5)
DivisibleWDivconstU16-4  1.88ns ± 0%  1.89ns ± 1%     ~     (p=0.365 n=5+5)
DivconstI8-4             1.54ns ± 1%  1.54ns ± 1%     ~     (p=1.000 n=5+5)
DivisibleconstI8-4       2.10ns ± 0%  2.11ns ± 0%     ~     (p=0.238 n=5+4)
DivisibleWDivconstI8-4   2.22ns ± 0%  2.23ns ± 2%     ~     (p=0.762 n=5+5)
DivconstU8-4             0.92ns ± 1%  0.94ns ± 1%   +2.65%  (p=0.008 n=5+5)
DivisibleconstU8-4       1.66ns ± 0%  1.26ns ± 1%  -24.28%  (p=0.008 n=5+5)
DivisibleWDivconstU8-4   1.79ns ± 0%  1.80ns ± 1%     ~     (p=0.079 n=4+5)

A follow-up change will address the signed division case.

Updates #30282

Change-Id: I7e995f167179aa5c76bb10fbcbeb49c520943403
Reviewed-on: https://go-review.googlesource.com/c/go/+/168037
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

* cmd/link/internal/ld: consolidate macho platform setup

Determine the macho platform once and use that the two places that
need it. This makes it easier to add a third platform check for a
follow-up change.

Updates #31447

Change-Id: I522a5fface647ab8e608f816c5832d531534df7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/174198
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

* cmd/link/internal/ld,syscall: drop $INODE64 suffixes on simulators

Some libc functions are suffixed with "$INODE64" on macOS.
Unfortunately, the iOS simulator doesn't have the suffixes, so we can't
use GOARCH to distinguish the two platform.

Add linker support for adding the suffix, using the macho platform
to determine whether it is needed.

While here, add the correct suffix for fdopendir on 386. It's
"$INODE64$UNIX2003", believe it or not. Without the suffix,

GOARCH=386 go test -short syscall

crashes on my Mojave machine.

Fixes #31447

Change-Id: I9bd3de40ece7df62f744bc24cd00909e56b00b78
Reviewed-on: https://go-review.googlesource.com/c/go/+/174199
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

* cmd/link/internal/ld,syscall: replace getfsstat64 with getfsstat

getfsstat64 is deprecated but not yet caught by the App Store checks.
Use the supported getfsstat$INODE64 form instead to ensure forward
compatibility.

Change-Id: I0d97e8a8b254debb3de1cfcb3778dbed3702c249
Reviewed-on: https://go-review.googlesource.com/c/go/+/174200
Run-TryBot: Elias Naur <mail@eliasnaur.com>
Reviewed-by: Keith Randall <khr@golang.org>

* cmd/go/internal/renameio: use ERROR_ACCESS_DENIED to check for errors

CL 172418 added code to check for "Access is denied" error.
But "Access is denied" error will be spelled differently on
non-English version of Windows.

Check if error is ERROR_ACCESS_DENIED instead.

Updates #31247

Change-Id: I7b1633013d563f7c06c1f12a9be75122106834f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/174123
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

* syscall: allow setting security attributes on processes

This allows creating processes that can only be debugged/accessed by
certain tokens, according to a particular security descriptor. We
already had everything ready for this but just neglected to pass through
the value from the user-accessible SysProcAttr.

Change-Id: I4a3fcc9f5078aa0058b26c103355c984093ae03f
Reviewed-on: https://go-review.googlesource.com/c/go/+/174197
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

* runtime: remove spurious register loads for openbsd/amd64 kqueue

The kqueue system call takes no arguments, hence there should be no need
to zero the registers used for the first syscall arguments.

Change-Id: Ia79b2d4f4d568bb6795cb885e1464cf1fc2bf7c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/174128
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>

* cmd/compile: intrinsify math/bits.Add64 for ppc64x

This change creates an intrinsic for Add64 for ppc64x and adds a
testcase for it.

name               old time/op  new time/op  delta
Add64-160          1.90ns ±40%  2.29ns ± 0%     ~     (p=0.119 n=5+5)
Add64multiple-160  6.69ns ± 2%  2.45ns ± 4%  -63.47%  (p=0.016 n=4+5)

Change-Id: I9abe6fb023fdf62eea3c9b46a1820f60bb0a7f97
Reviewed-on: https://go-review.googlesource.com/c/go/+/173758
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>

* runtime: whitelist debugCall32..debugCall65536 in debugCallCheck

Whitelists functions debugCall32 through debugCall65536 in
runtime.debugCallCheck so that any instruction inside those functions
is considered a safe point.
This is useful for implementing nested function calls.

For example when evaluating:

	f(g(x))

The debugger should:

1. initiate the call to 'f' until the entry point of 'f',
2. complete the call to 'g(x)'
3. copy the return value of 'g(x)' in the arguments of 'f'
4. complete the call to 'f'

Similarly for:

	f().amethod()

The debugger should initiate the call to '.amethod()', then initiate
and complete the call to f(), copy the return value to the arguments
of '.amethod()' and finish its call.
However in this example, unlike the other example, it may be
impossible to determine the entry point of '.amethod()' until after
'f()' is evaluated, which means that the call to 'f()' needs to be
initiated while stopped inside a debugCall... function.

Change-Id: I575c23542709cedb1a171d63576f7e11069c7674
Reviewed-on: https://go-review.googlesource.com/c/go/+/161137
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

* strconv: Document ParseFloat's special cases

Updates #30990

Change-Id: I968fb13251ab3796328089046a3f0fc5c7eb9df9
Reviewed-on: https://go-review.googlesource.com/c/go/+/174204
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/go: implement Go checksum database support

This CL adds support for consulting the Go checksum database
when downloading a module that is not already listed in go.sum.
The overall system is described at golang.org/design/25530-sumdb,
and this CL implements the functionality described specifically in
golang.org/design/25530-sumdb#command-client.

Although the eventual plan is to set GOPROXY and GOSUMDB to
default to a Google-run proxy serving the public Go ecosystem,
this CL leaves them off by default.

Fixes #30601.

Change-Id: Ie46140f93c6cc2d85573fbce0878a258819ff44d
Reviewed-on: https://go-review.googlesource.com/c/go/+/173951
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* encoding/json: add a Fuzz function

Adds a sample Fuzz test function to package encoding/json following the
guidelines defined in #31309, based on
https://github.com/dvyukov/go-fuzz-corpus/blob/master/json/json.go

Fixes #31309
Updates #19109

Change-Id: I5fe04d9a5f41c0de339f8518dae30896ec14e356
Reviewed-on: https://go-review.googlesource.com/c/go/+/174058
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* all: remove a few unused parameters

I recently modified tabwriter to reduce the number of defers due to
flush calls. However, I forgot to notice that the new function
flushNoDefers can no longer return an error, due to the lack of the
defer.

In crypto/tls, hashForServerKeyExchange never returned a non-nil error,
so simplify the code.

Finally, in go/types and net we can find a few trivially unused
parameters, so remove them.

Change-Id: I54c8de83fbc944df432453b55c93008d7e810e61
Reviewed-on: https://go-review.googlesource.com/c/go/+/174131
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>

* net/http: remove "number:" from Response.Status string

The behavior of Value.String method on non-string JavaScript types has
changed after CL 169757.

Update the implementation of Transport.RoundTrip method to construct the
Response.Status string without relying on result.Get("status").String(),
since that now returns strings like "<number: 200>" instead of "200".

Fixes #31736

Change-Id: I27b3e6cc95aa65fd1918b1400e88478a154aad12
Reviewed-on: https://go-review.googlesource.com/c/go/+/174218
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Richard Musiol <neelance@gmail.com>

* cmd/link/internal/s390x: fix s390x build

Fix breakage from CL 173437

Change-Id: If218ffaa1259fbdee641143ffbe4b38030c373b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/174278
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

* net: correct docs of KeepAlive field in Dialer type

KeepAlive field used to report the wording "keep-alive period"
which may be misleading. This field does not represent the whole
TCP keepalive time, that is the inactivity period upon which one
endpoint starts probing the other end. But it acctually specifies
the keepalive interval, that is the time between two keepalive
probes.

Fixes #29089

Change-Id: If99b38ba108830d0e5fe527171a2f5c96a3bcde7
Reviewed-on: https://go-review.googlesource.com/c/go/+/155960
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* misc/wasm: fix command line arguments containing multi-byte characters

Command line arguments containing multi-byte characters were causing
go_js_wasm_exec to crash (RangeError: Source is too large), because
their byte length was not handled correctly. This change fixes the bug.

Fixes #31645.

Change-Id: I7860ebf5b12da37d9d0f43d4b6a22d326a90edaf
Reviewed-on: https://go-review.googlesource.com/c/go/+/173877
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* runtime: initialise cpu.HWCap on openbsd/arm64

OpenBSD does not provide auxv, however we still need to initialise cpu.HWCap.
For now initialise it to the bare minimum, until some form of CPU capability
detection is implemented or becomes available - see issue #31746.

Updates #31656

Change-Id: I68c3c069319fe60dc873f46def2a67c9f3d937d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/174129
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* runtime: support all as parameter in gdb goroutine commands.

For example, can use `goroutine all bt` to dump all goroutines'
information.

Change-Id: I51b547c2b837913e4bdabf0f45b28f09250a3e34
GitHub-Last-Rev: d04dcd4f581f97e35ee45969a864f1270d79e49b
GitHub-Pull-Request: golang/go#26283
Reviewed-on: https://go-review.googlesource.com/c/go/+/122589
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: David Chase <drchase@google.com>

* os/exec: always set SYSTEMROOT on Windows if not listed in Cmd.Env

Fixes #25210

Change-Id: If27b61776154dae9b9b67bf4e4f5faa785d98105
Reviewed-on: https://go-review.googlesource.com/c/go/+/174318
Reviewed-by: Ian Lance Taylor <iant@golang.org>

* runtime/cgo: ignore missing Info.plist files on iOS

When running Go programs on Corellium virtual iPhones, the Info.plist
files might not exist. Ignore the error.

Updates #31722

Change-Id: Id2e315c09346b69dda9e10cf29fb5dba6743aac4
Reviewed-on: https://go-review.googlesource.com/c/go/+/174202
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* syscall: don't return EINVAL on zero Chmod mode on Windows

Fixes #20858

Change-Id: I45c397795426aaa276b20f5cbeb80270c95b920c
Reviewed-on: https://go-review.googlesource.com/c/go/+/174320
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* testing: delay flag registration; move to an Init function

Any code that imports the testing package forces the testing flags to be
defined, even in non-test binaries. People work around this today by
defining a copy of the testing.TB interface just to avoid importing
testing.

Fix this by moving flag registration into a new function, testing.Init.
Delay calling Init until the testing binary begins to run, in
testing.MainStart.

Init is exported for cases where users need the testing flags to be
defined outside of a "go test" context. In particular, this may be
needed where testing.Benchmark is called outside of a test.

Fixes #21051

Change-Id: Ib7e02459e693c26ae1ba71bbae7d455a91118ee3
Reviewed-on: https://go-review.googlesource.com/c/go/+/173722
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* runtime: make mmap return 0 instead of -1 on aix/ppc64

Most of the platforms are returning 0 instead of -1 when mmap syscalls
is failing. This patch corrects it for AIX in order to fix
TestMmapErrorSign and to improve AIX compatibility.

Change-Id: I1dad88d0e69163ad55c504b2b4a997892fd876cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/174297
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

* cmd/go: add XCOFF format handler for go version

Change-Id: Ib102ae95acfd89fc3c9942a4ec82c74362f62045
Reviewed-on: https://go-review.googlesource.com/c/go/+/174299
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

* runtime: account for callbacks in checkdead on Windows

When a callback runs on a different thread in Windows, as in the
runtime package test TestCallbackInAnotherThread, it will use the
extra M. That can cause the test in checkdead to fail incorrectly.
Check whether there actually is an extra M before expecting it.

I think this is a general problem unrelated to timers. I think the test
was passing previously because the timer goroutine was using an M.
But I haven't proved that. This change seems correct, and it avoids
the test failure when using the new timers on Windows.

Updates #27707

Change-Id: Ieb31c04ff0354d6fae7e173b59bcfadb8b0464cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/174037
Reviewed-by: Keith Randall <khr@golang.org>

* cmd,runtime: enable cgo for openbsd/arm64

Updates #31656.

Change-Id: Ide6f829282fcdf20c67998b766a201a6a92c3035
Reviewed-on: https://go-review.googlesource.com/c/go/+/174132
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

* cmd/compile: evaluate map initializers incrementally

For the code:

m := map[int]int {
  a(): b(),
  c(): d(),
  e(): f(),
}

We used to do:

t1 := a()
t2 := b()
t3 := c()
t4 := d()
t5 := e()
t6 := f()
m := map[int]int{}
m[t1] = t2
m[t3] = t4
m[t5] = t6

After this CL we do:

m := map[int]int{}
t1 := a()
t2 := b()
m[t1] = t2
t3 := c()
t4 := d()
m[t3] = t4
t5 := e()
t6 := f()
m[t5] = t6

Ordering the initialization this way limits the lifetime of the
temporaries involved.  In particular, for large maps the number of
simultaneously live temporaries goes from ~2*len(m) to ~2. This change
makes the compiler (regalloc, mostly) a lot happier. The compiler runs
faster and uses a lot less memory.

For #26546, changes compile time of a big map from 8 sec to 0.5 sec.

Fixes #26552

Update #26546

Change-Id: Ib7d202dead3feaf493a464779fd9611c63fcc25f
Reviewed-on: https://go-review.googlesource.com/c/go/+/174417
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

* cmd/go: add test of $GONOPROXY, $GONOSUMDB behavior

Change-Id: I8a4917ce14ea22d5991226e485d43a9c9312950e
Reviewed-on: https://go-review.googlesource.com/c/go/+/174219
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

* encoding/json: fix Unmarshal hang on recursive pointers

indirect walks down v until it gets to a non-pointer. But it does not
handle the case when v is a pointer to itself, like in:

	var v interface{}
	v = &v
	Unmarshal(b, v)

So just stop immediately if we see v is a pointer to itself.

Fixes #31740

Change-Id: Ie396264119e24d70284cd9bf76dcb2050babb069
Reviewed-on: https://go-review.googlesource.com/c/go/+/174337
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* runtime: do not use heap arena hints on wasm

The address space of WebAssembly's linear memory is contiguous, so
requesting specific addresses is not supported. Do not use heap arena
hints so we do not have unused memory ranges.

This fixes go1 benchmarks on wasm which ran out of memory since
https://golang.org/cl/170950.

Change-Id: I70115b18dbe43abe16dd5f57996343d97bf94760
Reviewed-on: https://go-review.googlesource.com/c/go/+/174203
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

* cmd/internal/obj/wasm: cache SP in a local

We use Wasm global variables extensively for simulating
registers, especially SP. V8 does not handle global variables
efficiently.

This CL reduces global variable accesses by caching the global SP
in a local variable in each function. The local cache is set on
function entry and updated after each call (where the stack could
have moved). Within a function, the SP access will use the local
variable.

Supersedes https://golang.org/cl/173979.

Running on Chrome Version 73.0.3683.103 on darwin/amd64:

name                   old time/op    new time/op     delta
BinaryTree17              15.3s ± 2%      14.5s ± 3%   -5.20%  (p=0.000 n=9+10)
Fannkuch11                8.91s ± 2%      9.48s ± 2%   +6.41%  (p=0.000 n=9+10)
FmtFprintfEmpty           197ns ± 5%      165ns ± 3%  -16.09%  (p=0.000 n=9+8)
FmtFprintfString          354ns ± 8%      325ns ± 7%   -8.33%  (p=0.001 n=10+10)
FmtFprintfInt             400ns ± 4%      368ns ± 6%   -8.01%  (p=0.000 n=10+10)
FmtFprintfIntInt          618ns ± 3%      587ns ± 6%   -4.97%  (p=0.001 n=10+10)
FmtFprintfPrefixedInt     637ns ± 4%      606ns ± 4%   -4.88%  (p=0.000 n=10+10)
FmtFprintfFloat           965ns ± 7%      898ns ± 4%   -6.97%  (p=0.000 n=10+10)
FmtManyArgs              2.34µs ± 1%     2.24µs ± 3%   -4.40%  (p=0.000 n=9+10)
GobDecode                29.8ms ± 3%     28.8ms ± 6%   -3.60%  (p=0.006 n=9+10)
GobEncode                20.5ms ± 8%     17.6ms ± 3%  -14.32%  (p=0.000 n=10+10)
Gzip                      714ms ± 3%      718ms ± 8%     ~     (p=0.971 n=10+10)
Gunzip                    148ms ± 3%      136ms ± 3%   -7.99%  (p=0.000 n=10+9)
HTTPClientServer          219µs ± 3%      215µs ± 4%     ~     (p=0.190 n=10+10)
JSONEncode               35.1ms ± 2%     31.8ms ±13%   -9.52%  (p=0.002 n=10+10)
JSONDecode                220ms ± 3%      207ms ± 5%   -5.87%  (p=0.000 n=10+10)
Mandelbrot200            5.22ms ± 1%     5.11ms ± 4%   -2.11%  (p=0.027 n=8+10)
GoParse                  17.2ms ± 6%     16.1ms ± 5%   -6.63%  (p=0.000 n=10+9)
RegexpMatchEasy0_32       375ns ± 3%      340ns ± 3%   -9.25%  (p=0.000 n=10+10)
RegexpMatchEasy0_1K      2.70µs ± 3%     2.65µs ± 4%     ~     (p=0.118 n=10+10)
RegexpMatchEasy1_32       341ns ± 2%      305ns ± 4%  -10.62%  (p=0.000 n=9+10)
RegexpMatchEasy1_1K      3.20µs ± 3%     2.99µs ± 3%   -6.35%  (p=0.000 n=10+10)
RegexpMatchMedium_32      520ns ± 3%      501ns ± 4%   -3.64%  (p=0.002 n=9+10)
RegexpMatchMedium_1K      145µs ± 7%      128µs ± 3%  -11.57%  (p=0.000 n=9+10)
RegexpMatchHard_32       7.88µs ± 3%     7.01µs ± 5%  -10.97%  (p=0.000 n=10+10)
RegexpMatchHard_1K        237µs ± 5%      207µs ± 4%  -12.71%  (p=0.000 n=9+10)
Revcomp                   2.34s ± 1%      2.31s ± 5%     ~     (p=0.230 n=7+10)
Template                  261ms ± 7%      246ms ± 5%   -5.93%  (p=0.007 n=10+10)
TimeParse                1.47µs ± 3%     1.39µs ± 5%   -5.75%  (p=0.000 n=9+10)
TimeFormat               1.52µs ± 3%     1.43µs ± 4%   -6.42%  (p=0.000 n=8+10)

name                   old speed      new speed       delta
GobDecode              25.7MB/s ± 3%   26.7MB/s ± 5%   +3.77%  (p=0.006 n=9+10)
GobEncode              37.5MB/s ± 8%   43.7MB/s ± 3%  +16.61%  (p=0.000 n=10+10)
Gzip                   27.2MB/s ± 3%   27.0MB/s ± 7%     ~     (p=0.971 n=10+10)
Gunzip                  131MB/s ± 3%    142MB/s ± 5%   +8.07%  (p=0.000 n=10+10)
JSONEncode             55.2MB/s ± 2%   61.2MB/s ±12%  +10.80%  (p=0.002 n=10+10)
JSONDecode             8.84MB/s ± 3%   9.39MB/s ± 5%   +6.28%  (p=0.000 n=10+10)
GoParse                3.37MB/s ± 6%   3.61MB/s ± 5%   +7.09%  (p=0.000 n=10+9)
RegexpMatchEasy0_32    85.3MB/s ± 3%   94.0MB/s ± 3%  +10.20%  (p=0.000 n=10+10)
RegexpMatchEasy0_1K     379MB/s ± 3%    387MB/s ± 4%     ~     (p=0.123 n=10+10)
RegexpMatchEasy1_32    93.9MB/s ± 2%  105.1MB/s ± 4%  +11.96%  (p=0.000 n=9+10)
RegexpMatchEasy1_1K     320MB/s ± 3%    342MB/s ± 3%   +6.79%  (p=0.000 n=10+10)
RegexpMatchMedium_32   1.92MB/s ± 2%   2.00MB/s ± 3%   +3.94%  (p=0.001 n=9+10)
RegexpMatchMedium_1K   7.09MB/s ± 6%   8.01MB/s ± 3%  +13.00%  (p=0.000 n=9+10)
RegexpMatchHard_32     4.06MB/s ± 3%   4.56MB/s ± 5%  +12.38%  (p=0.000 n=10+10)
RegexpMatchHard_1K     4.32MB/s ± 4%   4.96MB/s ± 4%  +14.60%  (p=0.000 n=9+10)
Revcomp                 109MB/s ± 1%    110MB/s ± 5%     ~     (p=0.219 n=7+10)
Template               7.44MB/s ± 8%   7.91MB/s ± 5%   +6.30%  (p=0.007 n=10+10)

Change-Id: I5828cf6b23ce104c02addc2642aba48dd6c48aab
Reviewed-on: https://go-review.googlesource.com/c/go/+/174062
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

* cmd/go/internal/modfetch: fix concurrent read/write race in modfetch

On Windows systems, the failure rate for cmd/go's TestScript/mod_concurrent
is somewhere around 3-10% without this change. With the change, I have yet
to see a failure.

Fixes #31744.

Change-Id: Ib321ebb9556dd8438086cf329dfa083a9e051732
Reviewed-on: https://go-review.googlesource.com/c/go/+/174439
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* encoding/csv: add a Fuzz function

Adds a sample Fuzz test function to package encoding/csv based on
https://github.com/dvyukov/go-fuzz-corpus/blob/master/csv/main.go

Updates #19109
Updates #31309

Change-Id: Ieb0cb6caa1df72dbb7e29df4bdeed0bfa91187d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/174302
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/go: say to confirm import path when it's not found

Fixes #31366.

Change-Id: Ief26f53e7fe94bedb7db79d3d7130c4cdcec4281
Reviewed-on: https://go-review.googlesource.com/c/go/+/174179
Run-TryBot: Jay Conrod <jayconrod@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* html: add a Fuzz function

Adds a sample Fuzz test function to package html based on
https://github.com/dvyukov/go-fuzz-corpus/blob/master/stdhtml/main.go

Updates #19109
Updates #31309

Change-Id: I8c49fff8f70fc8a8813daf1abf0044752003adbb
Reviewed-on: https://go-review.googlesource.com/c/go/+/174301
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/dist: disable cgo for darwin/386

Fixes #31751

Change-Id: Id002f14557a34accc3597cb1b9a42e838a027da4
Reviewed-on: https://go-review.googlesource.com/c/go/+/174497
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* runtime: implement pthread functions for darwin/arm64

They were not needed when Go only produced binaries with cgo suppport.
Now that Go is about to run self-hosted on iOS we do need these.

Updates #31722

Change-Id: If233aa2b31edc7b1c2dcac68974f9fba0604f9a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/174300
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

* cmd/link: add .go.buildinfo in XCOFF symbol table

.go.buildinfo must be added to the symbol table on AIX. Otherwise, ld
won't be able to handle its relocations.

This patch also make ".data" the default section for all symbols inside
the data segment.

Change-Id: I83ac2bf1050e0ef6ef9c96ff793efd4ddc8e98d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/174298
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* all: add new GOOS=illumos, split out of GOOS=solaris

Like GOOS=android which implies the "linux" build tag, GOOS=illumos
implies the "solaris" build tag. This lets the existing ecosystem of
packages still work on illumos, but still permits packages to start
differentiating between solaris and illumos.

Fixes #20603

Change-Id: I8f4eabf1a66060538dca15d7658c1fbc6c826622
Reviewed-on: https://go-review.googlesource.com/c/go/+/174457
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* runtime: fix data sizes for res_search results

The return values are 32 bit, not 64 bit.

I don't think this would be the cause of any problems, but
it can't hurt to fix it.

Change-Id: Icdd50606360ab9d74070271f9d1721d5fe640bc7
Reviewed-on: https://go-review.googlesource.com/c/go/+/174518
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/go/internal/modcmd: allow mod download without go.mod

Fixes #29522

Change-Id: I48f3a945d24c23c7c7ef5c7f1fe5046b6b2898e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/157937
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

* all: refer to map elements as elements instead of values

The spec carefully and consistently uses "key" and "element"
as map terminology. The implementation, not so much.

This change attempts to make the implementation consistently
hew to the spec's terminology. Beyond consistency, this has
the advantage of avoid some confusion and naming collisions,
since v and value are very generic and commonly used terms.

I believe that I found all everything, but there are a lot of
non-obvious places for these to hide, and grepping for them is hard.
Hopefully this change changes enough of them that we will start using
elem going forward. Any remaining hidden cases can be removed ad hoc
as they are discovered.

The only externally-facing part of this change is in package reflect,
where there is a minor doc change and a function parameter name change.

Updates #27167

Change-Id: I2f2d78f16c360dc39007b9966d5c2046a29d3701
Reviewed-on: https://go-review.googlesource.com/c/go/+/174523
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* encoding/gob: adding missing fuzz skip to one of the fuzz tests

It's slow & often times out randomly on longtest builders. Not useful.

Fixes #31517

Change-Id: Icedbb0c94fbe43d04e8b47d5785ac61c5e2d8750
Reviewed-on: https://go-review.googlesource.com/c/go/+/174522
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/dist: set the default external linker on platforms without gcc

The go tool already sets -extld to the appropriate compiler. This
CL changes cmd/dist to do the same, to fix bootstrapping on platforms
that only have clang (Android and iOS).

Updates #31722

Change-Id: I8a4fd227f85a768053a8946198eab68bbbdf9ae5
Reviewed-on: https://go-review.googlesource.com/c/go/+/174305
Run-TryBot: Elias Naur <mail@eliasnaur.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/dist: detect GOHOSTARCH on iOS

cmd/dist defaults to GOHOSTARCH=amd64 on darwin because no other
darwin host could build Go. With the upcoming self-hosted iOS
builders, GOHOSTARCH=arm64 is also possible.

Updates #31722

Change-Id: I9af47d9f8c57ea45475ce498acefbfe6bf4815b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/174306
Run-TryBot: Elias Naur <mail@eliasnaur.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/go: derive executable name from package path in 'go run'

Change name of temporary executable on go run . to directory name.
Fixes #31571

Change-Id: I0a0ce74154e76205bb43805c95bd7fb8fd2dfd01
GitHub-Last-Rev: e0964983e18a1d45b55f7098c7489059708c7e5e
GitHub-Pull-Request: golang/go#31614
Reviewed-on: https://go-review.googlesource.com/c/go/+/173297
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

* time: look for zoneinfo.zip in GOROOT

The zoneinfo.zip file will be in the $GOROOT in self-hsoted builds
on iOS.

Updates #31722

Change-Id: I991fae92e3dc50581b099a2d8901aed36ecc7cef
Reviewed-on: https://go-review.googlesource.com/c/go/+/174310
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/go: query modules in parallel

Refactor modload.QueryPackage and modload.QueryPattern to share code.

Fine-tune error reporting and make it consistent between QueryPackage and QueryPattern.

Expand tests for pattern errors.

Update a TODO in modget/get.go and add a test case that demonstrates it.

Updates #26232

Change-Id: I900ca8de338ef9a51b7f85ed93d8bcf837621646
Reviewed-on: https://go-review.googlesource.com/c/go/+/173017
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

* net/http: make Server return 501 for unsupported transfer-encodings

Ensures that our HTTP/1.X Server properly responds
with a 501 Unimplemented as mandated by the spec at
RFC 7230 Section 3.3.1, which says:
    A server that receives a request message with a
    transfer coding it does not understand SHOULD
    respond with 501 (Unimplemented).

Fixes #30710

Change-Id: I096904e6df053cd1e4b551774cc27523ff3d09f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/167017
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/go,cmd/internal/sys,cmd/link: skip Go build ids for externally linked tools

cmd/go already skips build ids on Android where buildmode=pie is
forced. Expand the check to all externally linked tools.

Necessary for self-hosted iOS builds where PIE is not forced but
external linking is.

Updates #31722

Change-Id: Iad796a9411a37eb0c44d365b70a3c5907537e461
Reviewed-on: https://go-review.googlesource.com/c/go/+/174307
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

* cmd/go/internal/modfetch/codehost: disable fetch of server-resolved commit hash

We cannot rely on the server to filter out the refs we don't want
(we only want refs/heads/* and refs/tags/*), so do not give it
the full hash.

Fixes #31191.

Change-Id: If1208c35954228aa6e8734f8d5f1725d0ec79c87
Reviewed-on: https://go-review.googlesource.com/c/go/+/174517
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/compile: remove dynamic entry handling from sinit/maplit

The order pass now handles all the dynamic entries.

Update #26552

Followup to CL 174417

Change-Id: Ie924cadb0e0ba36c423868f654f13040100b44c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/174498
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

* os: fix tests on self-hosted Go builds

Updates #31722

Change-Id: I467bb2539f993fad642abf96388a58a263fbe007
Reviewed-on: https://go-review.googlesource.com/c/go/+/174311
Run-TryBot: Elias Naur <mail@eliasnaur.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/asm: reject BSWAPW on amd64

Since BSWAP operation on 16-bit registers is undefined,
forbid the usage of BSWAPW. Users should rely on XCHGB instead.

This behavior is consistent with what GAS does.

Fixes #29167

Change-Id: I3b31e3dd2acfd039f7564a1c17e6068617bcde8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/174312
Run-TryBot: Iskander Sharipov <quasilyte@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/compile: fix line numbers for index panics

In the statement x = a[i], the index panic should appear to come from
the line number of the '['. Previous to this CL we sometimes used the
line number of the '=' instead.

Fixes #29504

Change-Id: Ie718fd303c1ac2aee33e88d52c9ba9bcf220dea1
Reviewed-on: https://go-review.googlesource.com/c/go/+/174617
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/compile: add signed divisibility rules

"Division by invariant integers using multiplication" paper
by Granlund and Montgomery contains a method for directly computing
divisibility (x%c == 0 for c constant) by means of the modular inverse.
The method is further elaborated in "Hacker's Delight" by Warren Section 10-17

This general rule can compute divisibilty by one multiplication, and add
and a compare for odd divisors and an additional rotate for even divisors.

To apply the divisibility rule, we must take into account
the rules to rewrite x%c = x-((x/c)*c) and (x/c) for c constant on the first
optimization pass "opt".  This complicates the matching as we want to match
only in the cases where the result of (x/c) is not also needed.
So, we must match on the expanded form of (x/c) in the expression x == c*(x/c)
in the "late opt" pass after common subexpresion elimination.

Note, that if there is an intermediate opt pass introduced in the future we
could simplify these rules by delaying the magic division rewrite to "late opt"
and matching directly on (x/c) in the intermediate opt pass.

On amd64, the divisibility check is 30-45% faster.

name                     old time/op  new time/op  delta`
DivisiblePow2constI64-4  0.83ns ± 1%  0.82ns ± 0%     ~     (p=0.079 n=5+4)
DivisibleconstI64-4      2.68ns ± 1%  1.87ns ± 0%  -30.33%  (p=0.000 n=5+4)
DivisibleWDivconstI64-4  2.69ns ± 1%  2.71ns ± 3%     ~     (p=1.000 n=5+5)
DivisiblePow2constI32-4  1.15ns ± 1%  1.15ns ± 0%     ~     (p=0.238 n=5+4)
DivisibleconstI32-4      2.24ns ± 1%  1.20ns ± 0%  -46.48%  (p=0.016 n=5+4)
DivisibleWDivconstI32-4  2.27ns ± 1%  2.27ns ± 1%     ~     (p=0.683 n=5+5)
DivisiblePow2constI16-4  0.81ns ± 1%  0.82ns ± 1%     ~     (p=0.135 n=5+5)
DivisibleconstI16-4      2.11ns ± 2%  1.20ns ± 1%  -42.99%  (p=0.008 n=5+5)
DivisibleWDivconstI16-4  2.23ns ± 0%  2.27ns ± 2%   +1.79%  (p=0.029 n=4+4)
DivisiblePow2constI8-4   0.81ns ± 1%  0.81ns ± 1%     ~     (p=0.286 n=5+5)
DivisibleconstI8-4       2.13ns ± 3%  1.19ns ± 1%  -43.84%  (p=0.008 n=5+5)
DivisibleWDivconstI8-4   2.23ns ± 1%  2.25ns ± 1%     ~     (p=0.183 n=5+5)

Fixes #30282
Fixes #15806

Change-Id: Id20d78263a4fdfe0509229ae4dfa2fede83fc1d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/173998
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

* cmd/go: make get -u upgrade only modules providing packages

Currently, 'go get -u' upgrades modules matching command line
arguments and any modules they transitively require. 'go get -u' with
no positional arguments upgrades all modules transitively required by
the main module. This usually adds a large number of indirect
requirements, which is surprising to users.

With this change, 'go get' will load packages specified by
its arguments using a similar process to other commands
('go build', etc). Only modules providing packages will be upgraded.

'go get -u' now upgrades modules providing packages transitively
imported by the command-line arguments. 'go get -u' without arguments
will only upgrade modules needed by the package in the current
directory.

'go get -m' will load all packages within a module. 'go get -m -u'
without arguments will upgrade modules needed by the main module. It
is equivalent to 'go get -u all'. Neither command will upgrade modules
that are required but not used.

Note that 'go get -m' and 'go get -d' both download modules in order
to load packages.

Fixes #26902

Change-Id: I2bad686b3ca8c9de985a81fb42b16a36bb4cc3ea
Reviewed-on: https://go-review.googlesource.com/c/go/+/174099
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

* syscall: on wasm, do not use typed array asynchronously

The underlying buffer of a typed array becomes invalid as soon as we
grow the WebAssembly memory, which can happen at any time while Go code
runs. This is a known limitation, see https://golang.org/cl/155778.

As a consequence, using a typed array with one of the asynchronous
read/write operations of Node.js' fs module is dangerous, since it may
become invalid while the asynchronous operation has not finished yet.
The result of this situation is most likely undefined.

I am not aware of any nice solution to this issue, so this change adds
a workaround of using an additional typed array which is not backed by
WebAssembly memory and copying the bytes between the two typed arrays.

Maybe WebAssembly will come up with a better solution in the future.

Fixes #31702.

Change-Id: Iafc2a0fa03c81db414520bd45a1a17c00080b61e
Reviewed-on: https://go-review.googlesource.com/c/go/+/174304
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

* net/http: add Transport.ReadBufferSize and WriteBufferSize

Previously transport was using the hardcoded bufio.defaultBufSize
(4096), limiting throughput and increasing cpu usage when uploading or
downloading large files.

Add options to allow users to configure the buffer sizes as needed.

I tested the maximum benefit of this change by uploading data from
/dev/zero to a server discarding the bytes. Here is an example upload
using the default buffer size:

$ time ./upload 10 https://localhost:8000/
Uploaded 10.00g in 25.13 seconds (407.49m/s)

real	0m25.135s
user	0m5.167s
sys	0m11.643s

With this change, using 128k buffer size:

$ time ./upload 10 https://localhost:8000/
Uploaded 10.00g in 7.93 seconds (1291.51m/s)

real	0m7.935s
user	0m4.517s
sys	0m2.603s

In real world usage the difference will be smaller, depending on the
local and remote storage and the network.

See https://github.com/nirs/http-bench for more info.

Fixes #22618

Change-Id: Iac99ed839c7b95d6dc66602ba8fe1fc5b500c47c
Reviewed-on: https://go-review.googlesource.com/c/go/+/76410
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* net/http: make Transport.MaxConnsPerHost work for HTTP/2

Treat HTTP/2 connections as an ongoing persistent connection. When we
are told there is no cached connections, cleanup the associated
connection and host connection count.

Fixes #27753

Change-Id: I6b7bd915fc7819617cb5d3b35e46e225c75eda29
Reviewed-on: https://go-review.googlesource.com/c/go/+/140357
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* internal/cpu: add detection for the new ECDSA and EDDSA capabilities on s390x

This CL will check for the Message-Security-Assist Extension 9 facility
which enables the KDSA instruction.

Change-Id: I659aac09726e0999ec652ef1f5983072c8131a48
Reviewed-on: https://go-review.googlesource.com/c/go/+/174529
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* net: set DNSError.IsTemporary from addrinfoErrno errors

Today it is not possible (AFAICT) to detect if a DNSError if of type EAI_AGAIN, i.e. if it is something temporary that should be retried. This information is available inside addrinfoErrno but when the DNSError is created this information is lost.

This PR fixes this so that the addinfoErrno.Temporary information is added to DNSError as well. With that a user who gets a DNSError can check now is its a temporary error (for errors that resulted from a addrinfoErrno this is EAI_AGAIN).

Change-Id: I64badb2ebd904e41fc2e0755416f7f32560534d8
GitHub-Last-Rev: ced7238a6597039fb23f36f372bd1cf33d60d4a6
GitHub-Pull-Request: golang/go#31676
Reviewed-on: https://go-review.googlesource.com/c/go/+/174557
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* os,time: fix tests on iOS

When fixing tests for for self-hosted iOS builds, I
broke hosted builds.

Updates #31722

Change-Id: Id4e7d234fbd86cb2d29d320d75f4441efd663d12
Reviewed-on: https://go-review.googlesource.com/c/go/+/174698
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* test: enable more memcombine tests for ppc64le

This enables more of the testcases in memcombine for ppc64le,
and adds more detail to some existing.

Change-Id: Ic522a1175bed682b546909c96f9ea758f8db247c
Reviewed-on: https://go-review.googlesource.com/c/go/+/174737
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* runtime: change the span allocation policy to first-fit

This change modifies the treap implementation to be address-ordered
instead of size-ordered, and further augments it so it may be used for
allocation. It then modifies the find method to implement a first-fit
allocation policy.

This change to the treap implementation consequently makes it so that
spans are scavenged in highest-address-first order without any
additional changes to the scavenging code. Because the treap itself is
now address ordered, and the scavenging code iterates over it in
reverse, the highest address is now chosen instead of the largest span.

This change also renames the now wrongly-named "scavengeLargest" method
on mheap to just "scavengeLocked" and also fixes up logic in that method
which made assumptions about size.

For #30333.

Change-Id: I94b6f3209211cc1bfdc8cdaea04152a232cfbbb4
Reviewed-on: https://go-review.googlesource.com/c/go/+/164101
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

* go/internal/gccgoimporter: skip new test with aliases with old gccgo

Add the issue31540 test to the list of tests that needs to be skipped
with old copies of gccgo. Along the way, add an explicit field to the
importer test struct that can be used to tag the test (as opposed to
having special cases by name in the test routine), so as to make it
easier to remember to tag testcases correctly.

Fixes #31764.

Change-Id: Ib9d98fea2df8ce0b51e5a886fb2c4acd6db490ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/174738
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/compile/internal/ppc64: improve naming for ginsnop2

This is a follow up from a review comment at the end of the last
Go release, to provide a more meaningful name for ginsnop2.

Updates #30475

Change-Id: Ice9efd763bf2204a9e8c55ae230d3e8a80210108
Reviewed-on: https://go-review.googlesource.com/c/go/+/174757
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

* index/suffixarray: add 32-bit implementation

The original index/suffixarray used 32-bit ints on 64-bit machines,
because that's what 'int' meant in Go at the time. When we changed
the meaning of int, that doubled the space overhead of suffix arrays
for all uses, even though the vast majority of them describe less
than 2 GB of text.

The space overhead of a suffix array compared to the text is not
insignificant: there's a big difference for many uses between 4X and 8X.

This CL adjusts names in qsufsort.go so that a global search and
replace s/32/64/g produces a working 64-bit implementation,
and then it modifies suffixarray.go to choose between the 32-bit
and 64-bit implementation as appropriate depending on the input size.
The 64-bit implementation is generated by 'go generate'.

This CL also restructures the benchmarks, to test different
input sizes, different input texts, and 32-bit vs 64-bit.

The serialized form uses varint-encoded numbers and is unchanged,
so on-disk suffix arrays written by older versions of Go will be
readable by this version, and vice versa.

The 32-bit version runs a up to 17% faster than the 64-bit version
on real inputs, but more importantly it uses 50% less memory.

I have a followup CL that also implements a faster algorithm
on top of these improvements, but these are a good first step.

name                                  64-bit speed   32-bit speed    delta
New/text=opticks/size=100K/bits=*-12  4.44MB/s ± 0%  4.64MB/s ± 0%   +4.41%  (p=0.008 n=5+5)
New/text=opticks/size=500K/bits=*-12  3.70MB/s ± 1%  3.82MB/s ± 0%   +3.30%  (p=0.008 n=5+5)
New/text=go/size=100K/bits=*-12       4.40MB/s ± 0%  4.61MB/s ± 0%   +4.82%  (p=0.008 n=5+5)
New/text=go/size=500K/bits=*-12       3.66MB/s ± 0%  3.77MB/s ± 0%   +3.01%  (p=0.016 n=4+5)
New/text=go/size=1M/bits=*-12         3.29MB/s ± 0%  3.55MB/s ± 0%   +7.90%  (p=0.016 n=5+4)
New/text=go/size=5M/bits=*-12         2.25MB/s ± 1%  2.65MB/s ± 0%  +17.81%  (p=0.008 n=5+5)
New/text=go/size=10M/bits=*-12        1.82MB/s ± 0%  2.09MB/s ± 1%  +14.36%  (p=0.008 n=5+5)
New/text=go/size=50M/bits=*-12        1.35MB/s ± 0%  1.51MB/s ± 1%  +12.33%  (p=0.008 n=5+5)
New/text=zero/size=100K/bits=*-12     3.42MB/s ± 0%  3.32MB/s ± 0%   -2.74%  (p=0.000 n=5+4)
New/text=zero/size=500K/bits=*-12     3.00MB/s ± 1%  2.97MB/s ± 0%   -1.13%  (p=0.016 n=5+4)
New/text=zero/size=1M/bits=*-12       2.81MB/s ± 0%  2.78MB/s ± 2%     ~     (p=0.167 n=5+5)
New/text=zero/size=5M/bits=*-12       2.46MB/s ± 0%  2.53MB/s ± 0%   +3.18%  (p=0.008 n=5+5)
New/text=zero/size=10M/bits=*-12      2.35MB/s ± 0%  2.42MB/s ± 0%   +2.98%  (p=0.016 n=4+5)
New/text=zero/size=50M/bits=*-12      2.12MB/s ± 0%  2.18MB/s ± 0%   +3.02%  (p=0.008 n=5+5)
New/text=rand/size=100K/bits=*-12     6.98MB/s ± 0%  7.22MB/s ± 0%   +3.38%  (p=0.016 n=4+5)
New/text=rand/size=500K/bits=*-12     5.53MB/s ± 0%  5.64MB/s ± 0%   +1.92%  (p=0.008 n=5+5)
New/text=rand/size=1M/bits=*-12       4.62MB/s ± 1%  5.06MB/s ± 0%   +9.61%  (p=0.008 n=5+5)
New/text=rand/size=5M/bits=*-12       3.09MB/s ± 0%  3.43MB/s ± 0%  +10.94%  (p=0.016 n=4+5)
New/text=rand/size=10M/bits=*-12      2.68MB/s ± 0%  2.95MB/s ± 0%  +10.39%  (p=0.008 n=5+5)
New/text=rand/size=50M/bits=*-12      1.92MB/s ± 0%  2.06MB/s ± 1%   +7.41%  (p=0.008 n=5+5)
SaveRestore/bits=*-12                  243MB/s ± 1%   259MB/s ± 0%   +6.68%  (p=0.000 n=9+10)

name                               64-bit alloc/op  32-bit alloc/op  delta
New/text=opticks/size=100K/bits=*-12    1.62MB ± 0%    0.81MB ± 0%  -50.00%  (p=0.000 n=5+4)
New/text=opticks/size=500K/bits=*-12    8.07MB ± 0%    4.04MB ± 0%  -49.89%  (p=0.008 n=5+5)
New/text=go/size=100K/bits=*-12         1.62MB ± 0%    0.81MB ± 0%  -50.00%  (p=0.008 n=5+5)
New/text=go/size=500K/bits=*-12         8.07MB ± 0%    4.04MB ± 0%  -49.89%  (p=0.029 n=4+4)
New/text=go/size=1M/bits=*-12           16.1MB ± 0%     8.1MB ± 0%  -49.95%  (p=0.008 n=5+5)
New/text=go/size=5M/bits=*-12           80.3MB ± 0%    40.2MB ± 0%     ~     (p=0.079 n=4+5)
New/text=go/size=10M/bits=*-12           160MB ± 0%      80MB ± 0%  -50.00%  (p=0.008 n=5+5)
New/text=go/size=50M/bits=*-12           805MB ± 0%     402MB ± 0%  -50.06%  (p=0.029 n=4+4)
New/text=zero/size=100K/bits=*-12       3.02MB ± 0%    1.46MB ± 0%     ~     (p=0.079 n=4+5)
New/text=zero/size=500K/bits=*-12       19.7MB ± 0%     8.7MB ± 0%  -55.98%  (p=0.008 n=5+5)
New/text=zero/size=1M/bits=*-12         39.0MB ± 0%    19.7MB ± 0%  -49.60%  (p=0.000 n=5+4)
New/text=zero/size=5M/bits=*-12          169MB ± 0%      85MB ± 0%  -49.46%  (p=0.029 n=4+4)
New/text=zero/size=10M/bits=*-12         333MB ± 0%     169MB ± 0%  -49.43%  (p=0.000 n=5+4)
New/text=zero/size=50M/bits=*-12        1.63GB ± 0%    0.74GB ± 0%  -54.61%  (p=0.008 n=5+5)
New/text=rand/size=100K/bits=*-12       1.61MB ± 0%    0.81MB ± 0%  -50.00%  (p=0.000 n=5+4)
New/text=rand/size=500K/bits=*-12       8.07MB ± 0%    4.04MB ± 0%  -49.89%  (p=0.000 n=5+4)
New/text=rand/size=1M/bits=*-12         16.1MB ± 0%     8.1MB ± 0%  -49.95%  (p=0.029 n=4+4)
New/text=rand/size=5M/bits=*-12         80.7MB ± 0%    40.3MB ± 0%  -50.06%  (p=0.008 n=5+5)
New/text=rand/size=10M/bits=*-12         161MB ± 0%      81MB ± 0%  -50.03%  (p=0.008 n=5+5)
New/text=rand/size=50M/bits=*-12         806MB ± 0%     403MB ± 0%  -50.00%  (p=0.016 n=4+5)
SaveRestore/bits=*-12                   9.47MB ± 0%    5.28MB ± 0%  -44.29%  (p=0.000 n=9+8)

https://perf.golang.org/search?q=upload:20190126.1+|+bits:64+vs+bits:32

Fixes #6816.

Change-Id: Ied2fbea519a202ecc43719debcd233344ce38847
Reviewed-on: https://go-review.googlesource.com/c/go/+/174097
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* runtime: look for idle p to run current goroutine when switching to GC or traceReader

This repairs one of the several causes of pauses uncovered
by a GC microbenchmark.  A pause can occur when a goroutine's
quantum expires "at the same time" a GC is needed.  The
current M switches to running a GC worker, which means that
the amount of available work has expanded by one.  The GC
worker, however, does not call ready, and does not itself
conditionally wake a P (a "normal" thread would do this).

This is also true if M switches to a traceReader.

This is problem 4 in this list:
https://github.com/golang/go/issues/27732#issuecomment-423301252

Updates #27732.

Change-Id: I6905365cac8504cde6faab2420f4421536551f0b
Reviewed-on: https://go-review.googlesource.com/c/go/+/146817
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

* cmd/go/internal/modfetch/codehost: fix pseudoversions for non-semver tags and tags on other branches

Pseudoversion determination depends in part on the results from gitRepo.RecentTag, which currently invokes:

git describe --first-parent --always --abbrev=0 --match <prefix>v[0-9]*.[0-9]*.[0-9]* --tags <rev>

The comment at https://github.com/golang/go/issues/27171#issuecomment-470134255 describes some problems with the current approach.

One problem is Docker and other repos can have tags that are not valid semver tags but that still match a glob pattern of v[0-9]*.[0-9]*.[0-9]* which are found by 'git describe' but then rejected by cmd/go, and hence those repos currently can end up with v0.0.0 pseudoversions instead of finding a proper semver tag to use as input to building a pseudoversion  (when then causes problems when the v0.0.0 pseudoversion is fed into MVS). An example problematic tag is a date-based tag such as 'v18.06.16', which matches the glob pattern, but is not a valid semver tag (due to the leading 0 in '06').

Issues #31673, #31287, and #27171 also describe problems where the '--first-parent' argument to 'git describe' cause the current approach to miss relevant semver tags that were created on a separate branch and then subsequently merged to master.

In #27171, Bryan described the base tag that is supposed to be used for pseudoversions as:

"It is intended to be the semantically-latest tag that appears on any commit that is a (transitive) parent of the commit with the given hash, regardless of branches. (The pseudo-version is supposed to sort after every version — tagged or otherwise — that came before it, but before the next tag that a human might plausibly want to apply to the branch.)"

This CL solves the glob problem and tags-on-other-branches problem more directly than the current approach: this CL gets the full list of tags that have been merged into the specific revision of interest, and then sorts and filters the results in cmd/go to select the semantically-latest valid semver tag.

Fixes #31673
Fixes #31287
Updates #27171

Change-Id: I7c3e6b46b2b21dd60562cf2893b6bd2afaae61d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/174061
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

* cmd/go/internal/get: fix strayed verbose output on stdout

Fixes #31768

Change-Id: I3cc0ebc4be34d7c2d2d4fd655bfd0c2515ff3021
Reviewed-on: https://go-review.googlesource.com/c/go/+/174739
Reviewed-by: Jay Conrod <jayconrod@google.com>
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/dist: only build exec wrappers when cross compiling

Updates #31722

Change-Id: Ib44b46e628e364fff6eacda2b26541db2f0a4261
Reviewed-on: https://go-review.googlesource.com/c/go/+/174701
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* misc/cgo/testcarchive: skip TestExtar on self-hosted iOS

iOS cannot (directly) run shell scripts.

Updates #31722

Change-Id: I69473e9339c50a77338d391c73b4e146bce3fa89
Reviewed-on: https://go-review.googlesource.com/c/go/+/174700
Run-TryBot: Elias Naur <mail@eliasnaur.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* strings, bytes: add ToValidUTF8

The newly added functions create a copy of their input with all bytes in
invalid UTF-8 byte sequences mapped to the UTF-8 byte sequence
given as replacement parameter.

Fixes #25805

Change-Id: Iaf65f65b40c0581c6bb000f1590408d6628321d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/142003
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/go: sort vendor/modules.txt package lists

Right now they are in a deterministic order
but one that depends on the shape of the import graph.
Sort them instead.

Change-Id: Ia0c076a0d6677a511e52acf01f38353e9895dec2
Reviewed-on: https://go-review.googlesource.com/c/go/+/174527
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/compile: fix maplit init panics for dynamic entry

golang.org/cl/174498 removes dynamic map entry handling in maplit, by
filtering the static entry only. It panics if it see a dynamic entry.
It relies on order to remove all dynamic entries.

But after recursively call order on the statics, some static entries
become dynamic, e.g OCONVIFACE node:

	type i interface {
		j()
	}
	type s struct{}

	func (s) j() {}

	type foo map[string]i

	var f = foo{
		"1": s{},
	}

To fix it, we recursively call order on each static entry, if it changed
to dynamic, put entry to dynamic then.

Fixes #31777

Change-Id: I1004190ac8f2d1eaa4beb6beab989db74099b025
Reviewed-on: https://go-review.googlesource.com/c/go/+/174777
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* cmd/go/internal/web: fix log message

The web package is now used for proxy fetches, so its logs shouldn't
start with "Parsing meta tags".

Change-Id: I22a7dce09e3a681544ee4b860f93c63336e547ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/174740
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/compile: disable Go1.13 language features for -lang=go1.12 and below

Fixes   #31747.
Updates #19308.
Updates #12711.
Updates #29008.
Updates #28493.
Updates #19113.

Change-Id: I76d2fdbc7698cc4e0f31b7ae24cbb4d28afbb6a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/174897
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

* errors: fix comment referencing the Wrapper interface

The Unwrap function performs a type assertion looking for the Wrapper
interface. The method of that interface is called Unwrap but the
interface itself is called Wrapper.

Change-Id: Ie3bf296f93b773d36015bcab2a0e6585d39783c7
GitHub-Last-Rev: 32b1a0c2f8bf8f3eaebf6de252571d82313e86e0
GitHub-Pull-Request: golang/go#31794
Reviewed-on: https://go-review.googlesource.com/c/go/+/174917
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* doc/go1.13: start doc, note macOS, FreeBSD deprecations

For #23011.
For #27619.

Change-Id: Id1f280993ecdfb07a7420926ca1c0f5b7872afbb
Reviewed-on: https://go-review.googlesource.com/c/go/+/174521
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/compile: remove outdate TODO in inl.go

Mid-stack inlining is enable now, see #19348, but we still can not
remove the special case for runtime.heapBits.nextArena, because
runtime.heapBits.next is too complex to be inlined
(cost 96 exceeds budget 80).

Change-Id: I04ea86509074afdc83a3f70d68b8a1a8829763d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/174839
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/go: make modconv test more robust

Change-Id: I3e75201c56779eda1bcd725691c72d384da56f73
Reviewed-on: https://go-review.googlesource.com/c/go/+/174840
Run-TryBot: Baokun Lee <nototon@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

* cmd/go/internal/modload: make 'list -u' consider current pseudoversion

As pointed out by thepudds in #30634, the 'list -u' documentation states that the current version should be considered for upgrade:
The -u flag adds information about available upgrades. When the latest version of a given module is newer than the current one, list -u sets the Module's Update field to information about the newer module.

In go 1.12.4 (and current tip), an older version will be suggested as upgrade to a newer pseudo version.

Updates: #30634

Change-Id: If2c8887198884b8e7ccb3a604908065aa1f1878a
Reviewed-on: https://go-review.googlesource.com/c/go/+/174206
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

* cmd/dist: don't generate exec wrappers for compatible cross compiles

This change will allow android/arm64 hosts to build for android/arm,
and likewise for iOS.

Updates #31722

Change-Id: Id410bd112abbab585ebb13b61fe4d3a38a1a81fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/174705
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

* cmd/link: support PIE mode with internal link on linux arm64

This CL improves internal link to provide basic support for cgo and PIE:
1, add support for GOT, PLT and GOTPLT.
2, add support for following ELF relocation types which have been used by std
   packages:
     R_AARCH64_ADR_GOT_PAGE
     R_AARCH64_LD64_GOT_LO12_NC
     R_AARCH64_ADR_PREL_PG_HI21
     R_AARCH64_ADD_ABS_LO12_NC
     R_AARCH64_LDST8_ABS_LO12_NC
     R_AARCH64_LDST32_ABS_LO12_NC
     R_AARCH64_LDST64_ABS_LO12_NC
     R_AARCH64_JUMP26
     R_AARCH64_ABS64
     R_AARCH64_PREL32
     R_AARCH64_PREL64

With this change, Go toolchain can be built in internal linking mode, and
pure Go programs can be built with PIE mode in internal linking mode on arm64.

Updates #10373
The prototype of this CL is contributed by Wei Xiao <wei.xiao@arm.com>

Change-Id: I2253923c69e855fd1524d54def309a961dce6247
Reviewed-on: https://go-review.googlesource.com/c/go/+/163579
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>

* sort: simplify bootstrap

We compile package sort as part of the compiler bootstrap,
to make sure the compiler uses a consistent sort algorithm
no matter what version of Go it is compiled against.
(This matters for elements that compare "equal" but are distinguishab…
@gopherbot
Copy link

@gopherbot gopherbot commented Aug 10, 2019

Change https://golang.org/cl/189718 mentions this issue: compiler: support new numeric literal syntax

gopherbot pushed a commit to golang/gofrontend that referenced this issue Aug 17, 2019
Support 0b, 0o, and hex floats.

Tested against test/literal2.go in the gc repo.

Updates golang/go#12711
Updates golang/go#19308
Updates golang/go#28493
Updates golang/go#29008

Change-Id: I2ab01255f529880a2bd8603107e3e1ae03a7a3e5
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/189718
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
jpf91 pushed a commit to D-Programming-GDC/gcc that referenced this issue Aug 18, 2019
    
    Support 0b, 0o, and hex floats.
    
    Tested against test/literal2.go in the gc repo.
    
    Updates golang/go#12711
    Updates golang/go#19308
    Updates golang/go#28493
    Updates golang/go#29008
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/189718


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@274614 138bc75d-0d04-0410-961f-82ee72b054a4
@golang golang locked and limited conversation to collaborators Aug 9, 2020
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Projects
None yet
Linked pull requests

Successfully merging a pull request may close this issue.

None yet
You can’t perform that action at this time.