Compiling expressions like:
s[s[s[s[s[s[s[s[s[s[s[s[i]]]]]]]]]]]]
make 5g and 6g run out of registers. Such expressions can arise
if a slice is used to represent a permutation and the user wants
to iterate it.
This is due to the usual problem of allocating registers before
going down the expression tree, instead of allocating them in a
postfix way.
The functions cgenr and agenr (that generate a value to a newly
allocated register instead of an existing location), are either
introduced or modified when they already existed to allocate
the new register as late as possible, and sudoaddable is disabled
for OINDEX nodes so that igen/agenr is used instead.
Update #4207.
R=dave, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6733055
This is an experiment in static analysis of Go programs
to understand which struct fields a program might use.
It is not part of the Go language specification, it must
be enabled explicitly when building the toolchain,
and it may be removed at any time.
After building the toolchain with GOEXPERIMENT=fieldtrack,
a specific field can be marked for tracking by including
`go:"track"` in the field tag:
package pkg
type T struct {
F int `go:"track"`
G int // untracked
}
To simplify usage, only named struct types can have
tracked fields, and only exported fields can be tracked.
The implementation works by making each function begin
with a sequence of no-op USEFIELD instructions declaring
which tracked fields are accessed by a specific function.
After the linker's dead code elimination removes unused
functions, the fields referred to by the remaining
USEFIELD instructions are the ones reported as used by
the binary.
The -k option to the linker specifies the fully qualified
symbol name (such as my/pkg.list) of a string variable that
should be initialized with the field tracking information
for the program. The field tracking string is a sequence
of lines, each terminated by a \n and describing a single
tracked field referred to by the program. Each line is made
up of one or more tab-separated fields. The first field is
the name of the tracked field, fully qualified, as in
"my/pkg.T.F". Subsequent fields give a shortest path of
reverse references from that field to a global variable or
function, corresponding to one way in which the program
might reach that field.
A common source of false positives in field tracking is
types with large method sets, because a reference to the
type descriptor carries with it references to all methods.
To address this problem, the CL also introduces a comment
annotation
//go:nointerface
that marks an upcoming method declaration as unavailable
for use in satisfying interfaces, both statically and
dynamically. Such a method is also invisible to package
reflect.
Again, all of this is disabled by default. It only turns on
if you have GOEXPERIMENT=fieldtrack set during make.bash.
R=iant, ken
CC=golang-dev
https://golang.org/cl/6749064
The only code change is in exp/gotype/gotype.go.
The latest reviewed version of exp/types is now
exp/types/staging.
First step toward replacing exp/types with
exp/types/staging.
R=iant
CC=golang-dev
https://golang.org/cl/6819071
1. Prepend racefuncenter() to fn->enter -- fn->enter can contain new() calls,
and we want them to be in the scope of the function.
2. Dump fn->enter and fn->exit.
3. Add TODO that OTYPESW expression can contain interesting memory accesses.
4. Ignore only _ names instead of all names starting with _.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6822048
- simplified assignment checking by removing duplicate code
- implemented field lookup (methods, structs, embedded fields)
- importing methods (not just parsing them)
- type-checking functions and methods
- typechecking more statements (inc/dec, select, return)
- tracing support for easier debugging
- handling nil more correctly (comparisons)
- initial support for [...]T{} arrays
- initial support for method expressions
- lots of bug fixes
All packages under pkg/go as well as pkg/exp/types typecheck
now with pkg/exp/gotype applied to them; i.e., a significant
amount of typechecking works now (several statements are not
implemented yet, but handling statements is almost trivial in
comparison with typechecking expressions).
R=rsc
CC=golang-dev
https://golang.org/cl/6768063
Use wrapper functions to tell scheduler what we are doing.
With this patch, and a separate patch to the go tool, all the
cgo tests pass with gccgo.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6812058
* Use -fgo-pkgpath and -gccgopkgpath rather than -fgo-prefix
and -gccgoprefix.
* Define GOPKGPATH when compiling .c or .s files for gccgo.
* Use -fgo-relative-import-path.
* Produce .o files for gccgo, not .[568] files.
* Pass -E when linking if using cgo.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6820064
The idea is to (1) process ninit of all nodes,
and (2) put instrumentation of ninit into the nodes themselves (not the top-level statement ninit).
Fixes#4304.
R=golang-dev, rsc
CC=golang-dev, lvd
https://golang.org/cl/6818049
When local declarations needed unexported types, these could
be missing in the export data.
Fixes build with -gcflags -lll, except for exp/gotype.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6813067
This should make the compiler emit errors specific to the bounds checking instead of overflow errors on the underlying types.
Updates #4232.
R=rsc
CC=golang-dev
https://golang.org/cl/6783054
Incorrect cast was causing panics when
calling String() on dnsMsg with dnsRR_A
answers.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6818043
Plan 9 and Go's lib9/fmt disagree on whether %#x includes the 0x prefix
when printing 0, because ANSI C gave bad advice long ago.
Avoiding that case makes binaries compiled on different systems compatible.
R=ken2
CC=akumar, golang-dev
https://golang.org/cl/6814066
defined by the PLTE chunk. Such pixels decode to opaque black,
which matches what libpng does.
Fixes#4319.
On my reading, the PNG spec isn't clear whether palette index values
outside of those defined by the PLTE chunk is an error, and if not,
what to do.
Libpng 1.5.3 falls back to opaque black. png_set_PLTE says:
/* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
* of num_palette entries, in case of an invalid PNG file that has
* too-large sample values.
*/
png_ptr->palette = (png_colorp)png_calloc(png_ptr,
PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color));
ImageMagick 6.5.7 returns an error:
$ convert -version
Version: ImageMagick 6.5.7-8 2012-08-17 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2009 ImageMagick Studio LLC
Features: OpenMP
$ convert packetloss.png x.bmp
convert: Invalid colormap index `packetloss.png' @ image.c/SyncImage/3849.
R=r
CC=golang-dev
https://golang.org/cl/6822065
Tailorings are represented by removing and reinserting entries from a linked list.
After all tailorings are done, missing weights are computed and verified.
This implementation assumes that entries that are used in expansions are not
reinserted at a later point. This considerably simplifies the implementation.
R=r
CC=golang-dev
https://golang.org/cl/6739052
incremental comparisons. Instead, processing is now done directly on colElems.
As a result, the size of the weights array is now reduced by 75%.
Details:
- Primary value of type 1 colElem is shifted by 1 bit so that primaries
of all types can be compared without shifting.
- Quaternary values are now stored in the colElem itself. This is possible
as quaternary values other than 0 or maxQuaternary are only needed when other
values are ignored.
- Simplified processWeights by removing cases that are needed for ICU but not
for us (our CJK primary values fit in a single value).
R=r
CC=golang-dev
https://golang.org/cl/6817054
It is common to close network connection while another goroutine is
blocked reading on another goroutine. This sequence corresponds to
windows calls to WSARecv to start io, followed by GetQueuedCompletionStatus
that blocks until io completes, and, finally, closesocket called from
another thread. We were expecting that closesocket would unblock
GetQueuedCompletionStatus, and it does, but not always
(http://code.google.com/p/go/issues/detail?id=4170#c5). Also that sequence
results in connection is being reset.
This CL inserts CancelIo between GetQueuedCompletionStatus and closesocket,
and waits for both WSARecv and GetQueuedCompletionStatus to complete before
proceeding to closesocket. This seems to fix both connection resets and
issue 4170. It also makes windows code behave similar to unix version.
Unfortunately, CancelIo needs to be called on the same thread as WSARecv.
So we have to employ strategy we use for connections with deadlines to
every connection now. It means, there are 2 unavoidable thread switches
for every io. Some newer versions of windows have new CancelIoEx api that
doesn't have these drawbacks, and this CL uses this capability when available.
As time goes by, we should have less of CancelIo and more of CancelIoEx
systems. Computers with CancelIoEx are also not affected by issue 4195 anymore.
Fixes#3710Fixes#3746Fixes#4170
Partial fix for issue 4195
R=golang-dev, mikioh.mikioh, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6604072
compiler_rt introduces a weak and hidden symbol compilerrt_abort_impl
into our pre-linked _all.o object, we have to handle it.
Fixes#4273.
R=iant, rsc, r
CC=golang-dev
https://golang.org/cl/6783050
Feature extraction was tested before, but not the final diffs.
This CL breaks function main into a smaller main + testable
compareAPI.
No functional changes.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/6820057
On 6g/linux:
benchmark old ns/op new ns/op delta
BenchmarkFDCT 4606 4241 -7.92%
BenchmarkIDCT 4187 3923 -6.31%
BenchmarkDecodeBaseline 3154864 3170224 +0.49%
BenchmarkDecodeProgressive 4072812 4017132 -1.37%
BenchmarkEncode 39406920 34596760 -12.21%
Stack requirements before (from 'go tool 6g -S'):
(scan.go:37) TEXT (*decoder).processSOS+0(SB),$1352-32
(writer.go:448) TEXT (*encoder).writeSOS+0(SB),$5344-24
after:
(scan.go:37) TEXT (*decoder).processSOS+0(SB),$1064-32
(writer.go:448) TEXT (*encoder).writeSOS+0(SB),$2520-24
Also, in encoder.writeSOS, re-use the yBlock scratch buffer for Cb and
Cr. This reduces the stack requirement slightly, but also avoids an
unlucky coincidence where a BenchmarkEncode stack split lands between
encoder.writeByte and bufio.Writer.WriteByte, which occurs very often
during Huffman encoding and is otherwise disasterous for the final
benchmark number. FWIW, the yBlock re-use *without* the s/int/int32/
change does not have a noticable effect on the benchmarks.
R=r
CC=golang-dev, rsc
https://golang.org/cl/6823043
Fix the problem with no cookie handling when sending
other than GET or HEAD request through
(*Client) Do(*Request) (*Resposne, error).
https://code.google.com/p/go/issues/detail?id=3985
Adds a function (*Client) send(*Request) (*Reponse, error):
- sets cookies from CookieJar to request,
- sends request
- parses a reply cookies and updates CookieJar
Fixes#3985
R=bradfitz
CC=gobot, golang-dev
https://golang.org/cl/6653049
Previously we converted a time to UTC *and* serialized the timezone of
the original time. With this change, we serialize a UTCTime in the
original timezone.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6817048
- make sure dclcontext == PAUTO only in function bodies
- introduce PDISCARD to discard declarations in bodies of repeated imports
- skip printing initializing OAS'es in export mode, assuming they only occur after ODCL's
- remove ODCL and the initializing OAS from inl.c:ishairy
- fix confused use of ->typecheck in typecheckinl: it's about the ->inl, not about the fn.
- debuging aids: print ntype on ONAMEs too and -Emm instead of -Ell.
fixes#2812
R=rsc
CC=golang-dev
https://golang.org/cl/6800043
includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054
adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie them to escretval
R=rsc, bradfitz
CC=dave, gobot, golang-dev, iant, rsc
https://golang.org/cl/6741044
Before this patch the test would close the file descriptor but
not the os.File. When the os.File was GC'ed, the finalizer
would close the file descriptor again. That would cause
problems if the same file descriptor were returned by a later
call to open in another test.
On my system:
> GOGC=30 go test
--- FAIL: TestPassFD (0.04 seconds)
passfd_test.go:62: FileConn: dup: bad file descriptor
FAIL
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6776053
setAddr was showing up in profiles due to string concatenation construction the os.File name field. netFD.sysfile's Name() is never used, except in dup() so I believe it is safe to avoid this allocation.
R=mikioh.mikioh, rsc
CC=golang-dev
https://golang.org/cl/6742058
- Allow secondary values below the default value in second form. This is
to support before tags for secondary values, as used by Chinese.
- Eliminate collation elements that are guaranteed to be immaterial
after a weight increment.
R=r
CC=golang-dev
https://golang.org/cl/6739051
includes step 0: synthesize outparams, from 6600044
step 1: give outparams loopdepth 0 and verify unchanged results
step 2: generate esc:$mask tags, but still tie to sink if a param has mask != 0
next step: use in esccall (and ORETURN with implicit OAS2FUNC) to avoid tying to sink
R=rsc
CC=golang-dev
https://golang.org/cl/6610054
in typecheck and walk, conversion from OAS2RECV to OAS2
and to OSELRECV2 duplicated the ->rlist->n to ->right
thereby destroying the strict tree-ness of the AST (up to
ONAMES) of course. Several recursions in esc.c and inl.c
and probably elsewhere assume nodes of the tree aren't duplicated.
rather than defensively code around this, i'd rather assert
these cases away and fix their cause.
(this was tripped in 6741044)
R=rsc
CC=golang-dev
https://golang.org/cl/6750043
It's common to use the go list command in shell scripts, but
currently it's awkward to print a string slice from the Package
type in a way that's easily parseable by the shell. For example:
go list -f '{{range .Deps}}{{.}}
{{end}}'
(and even that prints an unwanted new line at the end|).
To make this easier, this CL adds a "join" function to the
format template.
go list -f '{{join .Deps "\n"}}'
R=rsc, dsymonds, minux.ma, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6680044
Previously, multi-byte characters were not allowed. Also certain single-byte
characters, such as '-', were disallowed.
Fixes#3813.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6641052
I just realized that there is no good place for adding
exposed function or method tests because server, unicast
and multicast_test.go do test complicated multiple test
objects, platform behaviros, protocol behaviors and API,
at the same time. Perhaps splitting them into per test
object might be better, so this CL provides tests focused
on API.
R=rsc
CC=gobot, golang-dev
https://golang.org/cl/6501057
Someone new to the language may not know the connection between ints and arrays, which was the only thing that the previous error told you anything about.
Fixes#4256.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6739048
PauseNs is a circular buffer of recent pause times, and the
most recent one is at [((NumGC-1)+256)%256].
Also fix comments cross-linking the Go and C definition of
various structs.
R=golang-dev, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/6657047
