Explain wrapping and how to use Is and As in the package doc.
Explain "chain" in Is and As.
Updates #33364.
Change-Id: Ic06362106dbd129e33dd47e63176ee5355492086
Reviewed-on: https://go-review.googlesource.com/c/go/+/188737
Reviewed-by: Rob Pike <r@golang.org>
A brief description at the top the Standard Library section of the
changes to support error wrapping.
Fixes#33365.
Change-Id: Id5a3b2fe148d9bfb949f2cfc9e5d8a1613a0e219
Reviewed-on: https://go-review.googlesource.com/c/go/+/188798
Reviewed-by: Ian Lance Taylor <iant@golang.org>
CL 188817 improved the error message for a nonexistent version in a dependency.
This CL locks in that improvement in a regression test.
Fixes#33474
Change-Id: I6246b4995adee966f24eaebe491d35830aea8370
Reviewed-on: https://go-review.googlesource.com/c/go/+/188977
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Based on original fix from Mark Glines in golang.org/cl/186737
Fixes#31861
Change-Id: Ibd583a3aa8f8b8eefade998aa2ac757b55140937
Reviewed-on: https://go-review.googlesource.com/c/go/+/188957
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The two methods act the same, so make their documentation similar so
that people don't think they act differently.
Change-Id: If224692ef50870faf855d789380a614d1e724132
Reviewed-on: https://go-review.googlesource.com/c/go/+/188137
Reviewed-by: Rob Pike <r@golang.org>
CL #163058 moves interpretation of platform-specific errors to the
syscall package. Package syscall errors implement an Is method which
os.IsPermission etc. consult. This results in an unintended semantic
change to the os package predicate functions: The following program
now prints 'true' where it used to print 'false':
package main
import "os"
type myError struct{ error }
func (e myError) Is(target error) bool { return target == os.ErrPermission }
func main() { println(os.IsPermission(myError{})) }
Change the os package error predicate functions to only examine syscall
errors, avoiding this semantic change.
This CL does retain one minor semantic change: On Plan9, os.IsPermission
used to return true for any error with text containing the string
"permission denied". It now only returns true for a syscall.ErrorString
containing that text.
Change-Id: I6b512b1de6ced46c2f1cc8d264fa2495ae7bf9f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/188817
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The compiler can crash if the compiled code tries to
unconditionally read from a nil pointer. This should cause
the generated binary to panic, not the compiler.
Fixes#33438
Change-Id: Ic8fa89646d6968e2cc4e27da0ad9286662f8bc49
Reviewed-on: https://go-review.googlesource.com/c/go/+/188760
Reviewed-by: Austin Clements <austin@google.com>
Documents the work from:
* CL 163599
* CL 163737
which now uses the Request.Body's io.ReaderFrom implementation,
if available, and permits system level optimizations such as
"sendfile" to be used to transmit/upload the Body, which greatly
speeds up file uploads.
Updates #33396
Change-Id: I7b8315c4b3e57ad47bb9be2b0c838857875d4bd5
Reviewed-on: https://go-review.googlesource.com/c/go/+/188457
Reviewed-by: Andrew Bonventre <andybons@golang.org>
It is unclear whether the current definition of os.IsTimeout is
desirable or not. Drop ErrTimeout for now so we can consider adding it
(or some other error) in a future release with a corrected definition.
Fixes#33411
Change-Id: I8b880da7d22afc343a08339eb5f0efd1075ecafe
Reviewed-on: https://go-review.googlesource.com/c/go/+/188758
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The Effective Go document references the crypto/cipher Block
interface, but the parameters' names are swapped. This change
alignes them to the crypto definition, to avoid confusion.
Fixes#33432
Change-Id: I8b9aac4dc6af3eec968bbc8f3ee5366b99016fcc
Reviewed-on: https://go-review.googlesource.com/c/go/+/188797
Reviewed-by: Ian Lance Taylor <iant@golang.org>
There's a race here with fork/exec, enable the close-on-exec flag
for the new file descriptor.
Fixes#33405
Change-Id: If95bae97a52b7026a930bb3427e47bae3b0032ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/188537
Run-TryBot: Baokun Lee <nototon@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
As discussed in
https://github.com/golang/go/issues/32463#issuecomment-506833421
the classification of deadline-based timeouts as "temporary" errors is a
historical accident. I/O timeouts used to be duration-based, so they
really were temporary--retrying a timed-out operation could succeed. Now
that they're deadline-based, timeouts aren't temporary unless you reset
the deadline.
Drop ErrTemporary from Go 1.13, since its definition is wrong. We'll
consider putting it back in Go 1.14 with a clear definition and
deprecate net.OpError.Temporary.
Fixes#32463
Change-Id: I70cda664590d8872541e17409a5780da76920891
Reviewed-on: https://go-review.googlesource.com/c/go/+/188398
Reviewed-by: Jonathan Amsterdam <jba@google.com>
We shouldn't mask to desired registers if we haven't masked out all the
forbidden registers yet. In this path we haven't masked out the nospill
registers yet. If the resulting mask contains only nospill registers, then
allocReg fails.
This can only happen on resultNotInArgs-marked instructions, which exist
only on the ARM64, MIPS, MIPS64, and PPC64 ports.
Maybe there's a better way to handle resultNotInArgs instructions.
But for 1.13, this is a low-risk fix.
Fixes#33355
Change-Id: I1082f78f798d1371bde65c58cc265540480e4fa4
Reviewed-on: https://go-review.googlesource.com/c/go/+/188178
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Also add other gccgo options.
This ports CL 45695 and CL 48592 from the gofrontend repo to the gc repo.
CL 45695 (partial entry, other parts out of date and not ported):
cmd/go: gccgo: consistent results
Pass the -fdebug-prefix-map and -gno-record-gcc-switches compiler
options to gccgo to generate consistent results.
CL 48592:
cmd/go: use gccSupportsFlag for -fsplit-stack
Don't assume that all (or only) 386/amd64 compilers support
-fsplit-stack.
Fixes#33108
Change-Id: I61f9e5a67e4fb059f26750e97621d27afa566ec2
Reviewed-on: https://go-review.googlesource.com/c/go/+/187824
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
In preparation for the forthcoming spec changes for #6977.
While at it, modernize existing File example that dates
back all the way to commit 18c5b488a3.
Change-Id: Id10e4df0513e3de15bd58867222923eefa9473ea
Reviewed-on: https://go-review.googlesource.com/c/go/+/187978
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Request.PostForm gets populated with form data for PATCH, POST, or PUT
http verbs.
Change-Id: I33065aa78a8470c4e9490aac830aa6f5963c61cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/187821
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
ioutil.WriteFile always truncates the destination file to 0 before
writing, which is inappropriate for unsynchronized, idempotent,
fixed-size files such as the cache entry files here.
Instead, truncate the file only after writing it, so that a second
write will never (even temporarily!) remove the contents of a
preceding write.
Fixes#29667
Change-Id: I16a53ce79d8a23d23580511cb6abd062f54b65ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/188157
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Currently when we coalesce memory we make a sysHugePage call
(MADV_HUGEPAGE) to ensure freed and coalesced huge pages are treated as
such so the scavenger's assumptions about performance are more in line
with reality.
Unfortunately we do it way too often because we do it if there was any
change to the huge page count for the span we're coalescing into, not
taking into account that it could coalesce with its neighbors and not
actually create a new huge page.
This change makes it so that it only calls sysHugePage if the original
huge page counts between the span to be coalesced into and its neighbors
do not add up (i.e. a new huge page was created due to alignment). Calls
to sysHugePage will now happen much less frequently, as intended.
Updates #32828.
Change-Id: Ia175919cb79b730a658250425f97189e27d7fda3
Reviewed-on: https://go-review.googlesource.com/c/go/+/186926
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This change adds physHugePageShift which is defined such that
1 << physHugePageShift == physHugePageSize. The purpose of this variable
is to avoid doing expensive divisions in key functions, such as
(*mspan).hugePages.
This change also does a sweep of any place we might do a division or mod
operation with physHugePageSize and turns it into bit shifts and other
bitwise operations.
Finally, this change adds a check to mallocinit which ensures that
physHugePageSize is always a power of two. osinit might choose to ignore
non-powers-of-two for the value and replace it with zero, but mallocinit
will fail if it's not a power of two (or zero). It also derives
physHugePageShift from physHugePageSize.
This change helps improve the performance of most applications because
of how often (*mspan).hugePages is called.
Updates #32828.
Change-Id: I1a6db113d52d563f59ae8fd4f0e130858859e68f
Reviewed-on: https://go-review.googlesource.com/c/go/+/186598
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This is intended to help clear up confusion around the usage of the
Title and ToTitle functions. It includes a link to define title case
to distinguish it from upper case. It also includes an additional
example for the ToTitle function to showcase the difference in behavior
between it and the Title function.
Fixes#33302
Change-Id: I44e62962fb04d0d22966a39eda3a2d16de7a2291
Reviewed-on: https://go-review.googlesource.com/c/go/+/187825
Reviewed-by: Rob Pike <r@golang.org>
Overflow of the comparison caused very large (>=1<<32) allocations to
sometimes not get sampled at all. Use uintptr so the comparison will
never overflow.
Fixes#33342
Tested on the example in 33342. I don't want to check a test in that
needs that much memory, however.
Change-Id: I51fe77a9117affed8094da93c0bc5f445ac2d3d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/188017
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Also, reorder packages so the list is in alphabetical order.
Fixes#32914.
Change-Id: Ifa504cb7e48df31ba6dc0e5756148430b59fa139
Reviewed-on: https://go-review.googlesource.com/c/go/+/187797
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Spotted while seeing CL 187818 in master.
Change-Id: Ic3f42558f6833fc35580b2b2a15f2c5aba5713c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/187822
Reviewed-by: Ian Lance Taylor <iant@golang.org>
As noticed while mentoring at Gophercon, a common mistake for
beginners is that, after they install git-codereview, it's not
found by git because they haven't put GOPATH/bin in their
environment.
Change-Id: I885cee0f532a4069d1a17ea27365d54965ecca22
Reviewed-on: https://go-review.googlesource.com/c/go/+/187818
Reviewed-by: Katie Hockman <katie@golang.org>
Document that *os.File is subject to resource limits
for concurrent operations. We aren't documenting
a specific number of concurrent operations because that
number is OS/system dependent. This limit comes from:
internal/poll/fd_mutex.go
where we use 20 bits to count locks.
Fixes#32544
Change-Id: I7d305d4aaba5b2dbc6f1ab8c447117fde5e31a66
Reviewed-on: https://go-review.googlesource.com/c/go/+/181841
Reviewed-by: Rob Pike <r@golang.org>
This reverts CL 176098.
Reason for revert: added complexity, but did not completely fix the
underlying problem. A complete solution would not be worth the
complexity, and as a partial solution this is probably not worth the
complexity either.
Updates #31859
Change-Id: Ifd34c292fd1b811c60afe3c339e5edd3f37190c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/186817
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Caleb Spare <cespare@gmail.com>
Currently, GODEBUG=sbrk=1 mode aligns allocations by their type's
alignment. You would think this would be the right thing to do, but
because 64-bit fields are only 4-byte aligned right now (see #599),
this can cause a 64-bit field of an allocated object to be 4-byte
aligned, but not 8-byte aligned. If there is an atomic access to that
unaligned 64-bit field, it will crash.
This doesn't happen in normal allocation mode because the
size-segregated allocation and the current size classes will cause any
types larger than 8 bytes to be 8 byte aligned.
We fix this by making sbrk=1 mode use alignment based on the type's
size rather than its declared alignment. This matches how the tiny
allocator aligns allocations.
This was tested with
GOARCH=386 GODEBUG=sbrk=1 go test sync/atomic
This crashes with an unaligned access before this change, and passes
with this change.
This should be reverted when/if we fix#599.
Fixes#33159.
Change-Id: Ifc52c72c6b99c5d370476685271baa43ad907565
Reviewed-on: https://go-review.googlesource.com/c/go/+/186919
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
'go test' uses the Root field to determine the set of files that
invalidate test results, and there is no other sensible meaning of
“root” for code within a module.
Fixes#29111
Change-Id: Icf1be90a26d22665613e42cb968087b63c36e74c
Reviewed-on: https://go-review.googlesource.com/c/go/+/154100
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
