Some versions of clang generate DWARF 4-format attributes
even when using -gdwarf-2. We don't care much about the
values, but we do need to be able to parse past them.
This fixes a bug in Go 1.2 rc2 reported via private mail using
a near-tip version of clang.
R=golang-dev, iant, dvyukov
CC=golang-dev
https://golang.org/cl/18460043
This flag was added in January 2010, in CL 181102, to fix issue 497.
(Numbers were just shorter back then.) The fix was for OS X machines
and the llvm-gcc frontend.
In July 2011 we had to change the way we get enum values, because
there were no flags available to force Xcode's llvm-gcc to include the
enum names and values in DWARF debug output.
We now use clang, not llvm-gcc, on OS X machines.
Earlier versions of clang printed a warning about not knowing the flag.
Newer versions of clang now make that an error.
That is:
- The flag was added for OS X machines.
- The flag is no longer necessary on OS X machines.
- The flag now breaks some OS X machines.
Remove it.
I have run the original program from issue 497 successfully
without the flag on both OS X and Linux machines.
Fixes#6678.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/18850043
The case can happen when starttheworld is calling acquirep
to get things moving again and acquirep gets preempted.
The stack trace is in golang.org/issue/6644.
It is difficult to build a short test case for this, but
the person who reported issue 6644 confirms that this
solves the problem.
Fixes#6644.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/18740044
Encoded query strings are always sorted by key; the example wasn't.
R=golang-dev, dsymonds, minux.ma, bradfitz
CC=golang-dev
https://golang.org/cl/16430043
singleStringReplacer had a bug where if a string was replaced
at the beginning and no output had yet been produced into the
temp buffer before matching ended, an invalid nil check (used
as a proxy for having matched anything) meant it always
returned its input.
Fixes#6659
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/16880043
The routines in this file are dregs from a very early copy of the math API.
There are no Go prototypes and no non-amd64 implementations.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/15750046
The code was requiring that all constraints be met, but it should be
satisfied by meeting *any* of them.
R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/15570044
Despite SHA256 support being required for TLS 1.2 handshakes, some
servers are aborting handshakes that don't offer SHA1 support.
This change adds support for signing TLS 1.2 ServerKeyExchange messages
with SHA1. It does not add support for signing TLS 1.2 client
certificates with SHA1 as that would require the handshake to be
buffered.
Fixes#6618.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/15650043
The old approach to determining whether "name" was a type, constant,
or expression was to compile the C program
name;
and scan the errors and warnings generated by the compiler.
This requires looking for specific substrings in the errors and warnings,
which ties the implementation to specific compiler versions.
As compilers change their errors or drop warnings, cgo breaks.
This happens slowly but it does happen.
Clang in particular (now required on OS X) has a significant churn rate.
The new approach compiles a slightly more complex program
that is either valid C or not valid C depending on what kind of
thing "name" is. It uses only the presence or absence of an error
message on a particular line, not the error text itself. The program is:
// error if and only if name is undeclared
void f1(void) { typeof(name) *x; }
// error if and only if name is not a type
void f2(void) { name *x; }
// error if and only if name is not an integer constant
void f3(void) { enum { x = (name)*1 }; }
I had not been planning to do this until Go 1.3, because it is a
non-trivial change, but it fixes a real Xcode 5 problem in Go 1.2,
and the new code is easier to understand than the old code.
It should be significantly more robust.
Fixes#6596.
Fixes#6612.
R=golang-dev, r, james, iant
CC=golang-dev
https://golang.org/cl/15070043
Nomemprof seems to be unneeded now, there is no recursion.
If the recursion will be re-introduced, it will break loudly by deadlocking.
Fixes#6566.
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/14695044
Only add a slash to path if it's a separator between
a host and path.
Fixes#6609
R=golang-dev, dsymonds, r
CC=golang-dev
https://golang.org/cl/14815043
New test added in CL 14611045 causes a deadlock when
running the tests with -cpu=n,n because the fakedb
driver always waits when opening a new connection after
running TestConnectionLeak. Reset its state after.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/14780043
CL 10726044 introduced a race condition which causes connections
to be leaked under certain circumstances. If SetMaxOpenConns is
used, the application eventually deadlocks. Otherwise, the number
of open connections just keep growing indefinitely.
Fixes#6593
R=golang-dev, bradfitz, tad.glines, bketelsen
CC=golang-dev
https://golang.org/cl/14611045
Add a check at the end of every test to make sure
there are no leaked connections after running a test.
Avoid incorrectly decrementing the number of open connections
when the driver connection ends up it a bad state (numOpen was
decremented twice).
Prevent leaking a Rows struct (which ends up leaking a
connection) in Row.Scan() when a *RawBytes destination is
improperly used.
Close the Rows struct in TestRowsColumns.
Update #6593
R=golang-dev, bradfitz, dave
CC=golang-dev
https://golang.org/cl/14642044
The preamble may want to #define some special symbols
and then #include <sys/types.h> itself. The builtin prolog
also #includes <sys/types.h>, which would break such a
preamble (because the second #include will be a no-op).
The use of sys/types.h in the builtin prolog is new since Go 1.1,
so this should preserve the semantics of more existing cgo
code than we would otherwise.
It also fixes src/pkg/syscall/mkall.sh's use of go tool cgo -godefs
on some Linux systems.
Thanks to fullung@ for identifying the problem.
Fixes#6558.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/14684044
Ensure that clang always exits with a non-zero status by
giving it something that it always warns about (the statement "1;").
Fixes#6128.
R=golang-dev, iant, minux.ma
CC=golang-dev
https://golang.org/cl/14702043
make use of $USER or %USERNAME% to determine the current user.
Fixes#6578.
R=golang-dev, bradfitz, alex.brainman
CC=golang-dev
https://golang.org/cl/14649043
Also add the action's object directory to the list of
directories we use to find SWIG shared libraries.
Fixes#6521.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/14369043
Fixes a bug in cgo on OS X using clang.
See golang.org/issue/6472 for details.
Fixes#6472.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/14575043
Also tweak the package document, putting in section headings and
adding a sentence about intended use.
Fixes#4925.
R=golang-dev, iant, adg, ugorji
CC=golang-dev
https://golang.org/cl/14519044
Instead of adding an -march=armv5t flag to the gcc command
line, the same effect is obtained with an ".arch armv5t"
pseudo op in the assembly file that uses armv5t instructions.
R=golang-dev, iant, dave
CC=golang-dev
https://golang.org/cl/14511044
All of the currently supported platforms have a working user
implementation and do not use stubs. As a result, enable the tests
on all platforms rather than whitelisting.
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/14454044
If an iterator is started while a map is in the middle of a grow,
and the map has NaN keys, then those keys might get returned by
the iterator more than once. This fix makes the evacuation decision
deterministic and repeatable for NaN keys so each one gets returned
only once.
R=golang-dev, r, khr, iant
CC=golang-dev
https://golang.org/cl/14367043
Failure occurred when using reflect.Call to pass a func value
following a non-pointer value.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/14186043
Explain for those unfamiliar with twos-complement arithmetic how to
implement negation of signed positive constant.
Fixes#6408.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/14267044
Changing from 4 kB to 8 kB brings significant improvement
on a variety of the Go 1 benchmarks, on both amd64
and 386 systems.
Significant runtime reductions:
amd64 386
GoParse -14% -1%
GobDecode -12% -20%
GobEncode -64% -1%
JSONDecode -9% -4%
JSONEncode -15% -5%
Template -17% -14%
In the longer term, khr's new stacks will avoid needing to
make this decision at all, but for Go 1.2 this is a reasonable
stopgap that makes performance significantly better.
Demand paging should mean that if the second 4 kB is not
used, it will not be brought into memory, so the change
should not adversely affect resident set size.
The same argument could justify bumping as high as 64 kB
on 64-bit machines, but there are diminishing returns
after 8 kB, and using 8 kB limits the possible unintended
memory overheads we are not aware of.
Benchmark graphs at
http://swtch.com/~rsc/gostackamd64.htmlhttp://swtch.com/~rsc/gostack386.html
Full data at
http://swtch.com/~rsc/gostack.zip
R=golang-dev, khr, dave, bradfitz, dvyukov
CC=golang-dev
https://golang.org/cl/14317043
Add the -installsuffix flag to gc and {5,6,8}l, which overrides -race
for the suffix if both are supplied.
Pass this flag from the go tool for build and install.
R=rsc
CC=golang-dev
https://golang.org/cl/14246044
It is not possible to use (there is no declaration in package syscall),
and no one seems to care.
Alex Brainman may bring this back properly for Go 1.3.
Fixes#6338.
R=golang-dev, r, alex.brainman
CC=golang-dev
https://golang.org/cl/14287043
RawMessage is useful and mildly non-obvious.
Given the frequency with which RawMessage questions
show up on golang-nuts, and get answered with an example,
I suspect adding an example to the docs might help.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/14190044
Not scanning the stack by frames means we are reintroducing
a few false positives into the collection. Run the finalizer registration
in its own goroutine so that stack is guaranteed to be out of
consideration in a later collection.
This is working around a regression from yesterday's tip, but
it's not a regression from Go 1.1.
R=golang-dev
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/14290043
Ticket 13740047 updated the documented TLS version to 1.2.
This also updates the RFC refered to.
R=golang-dev
CC=golang-dev, rsc
https://golang.org/cl/14029043
Added a new $GO_DISTFLAGS to make.bash, and while we're here,
added mention $CXX in make.bash (CL 13704044).
Fixes#6448.
Update #3564
We can pass GO_DISTFLAGS=-s from misc/dist to make.bash so that
it will build a statically linked toolchain.
(Note: OS X doesn't have the concept of static linking, so don't
pass GO_DISTFLAGS=-s for OS X builds)
R=adg, rsc, iant
CC=golang-dev
https://golang.org/cl/13887043
Currently, the directories generaed by includeArgs can have the "_race"
suffix added if invoked with -race flag, but ignores -installsuffix if
set.
R=adg, rsc
CC=golang-dev
https://golang.org/cl/14174043
Fixes#5537.
To avoid `go install -v race std` replacing cmd/cgo with a race enabled version and another package trying to build a cgo enabled package, always build cmd/cgo race enabled before doing the rest of the build.
R=remyoudompheng, rsc, dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/14071044
The argument slice was kept hidden from the garbage collector
by destroying its referent in an unsafe.Pointer to uintptr
conversion. This change preserves the unsafe.Pointer referent
and only performs an unsafe.Pointer to uintptr conversions
within expressions that construct new unsafe.Pointer values.
R=golang-dev, khr, rsc
CC=golang-dev
https://golang.org/cl/14008043
AES-GCM cipher suites are only defined for TLS 1.2, although there's
nothing really version specific about them. However, development
versions of NSS (meaning Firefox and Chrome) have an issue where
they'll advertise TLS 1.2-only cipher suites in a TLS 1.1 ClientHello
but then balk when the server selects one.
This change causes Go clients not to advertise TLS 1.2 cipher suites
unless TLS 1.2 is being used, and prevents servers from selecting them
unless TLS 1.2 has been negotiated.
https://code.google.com/p/chromium/issues/detail?id=297151https://bugzilla.mozilla.org/show_bug.cgi?id=919677
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13573047
Use the symbol prefixes with the prologue functions when using
gccgo.
Use an & when referring to a function declared as a variable.
Fix the malloc prologue function.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13878043
After text/template.Parse, all the templates may have changed, so
we need to set them all back to their unescaped state. The code
did this but (mea culpa) forgot to set the Tree field of the html/template
struct.
Since the Tree is reset during escaping, this only matters if an error
arises during escaping and we want to print a message.
Fixes#6459.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13877043
If Slice3 is set, the expression is
a 3-index slice expression (2 colons).
Required for type-checking.
Backward-compatible API extension.
R=r, rsc
CC=golang-dev
https://golang.org/cl/13826050
Since CL 38bf89161a72 raw socket tests are not executed
on windows builders. This change re-enable them again.
It will attempt to run raw socket tests only if user
is permitted to create raw socket by OS.
Fixes#6392
R=golang-dev
CC=golang-dev, mikioh.mikioh, rsc
https://golang.org/cl/13422044
newTypeEncoder (called once per type and then cached) was
looking at the first value seen of that type's addressability
and caching the encoder decision. If the first value seen was
addressable and a future one wasn't, it would panic.
Instead, introduce a new wrapper encoder type that checks
CanAddr at runtime.
Fixes#6458
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13839045
Makes build unnecessarily slower. Will fix the parser instead.
««« original CL description
runtime/pprof: run TestGoroutineSwitch for longer
Short test now takes about 0.5 second here.
Fixes#6417.
The failure was also seen on our builders.
R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/13321048
»»»
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13720048
In an indexed verb such as %[3]d, if the index is out of range, don't
skip processing the rest of the verbs. The bug was that the bad
index set a bit for the whole format instead of just the verb.
Ok for 1.2 because this is a bug in a 1.2 feature.
Fixes#6434
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/13632058
Date header indicated that it contained GMT time,
however it actually sent local time. Fixed by
converting time to UTC.
Also fixes incorrect comment in appendTime().
Regression since CL 9432046.
R=golang-dev, dave, bradfitz
CC=golang-dev
https://golang.org/cl/13386047
Short test now takes about 0.5 second here.
Fixes#6417.
The failure was also seen on our builders.
R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/13321048
The line number alone does not help when the line is
case '~', '*', '(', ')', '[', ']', '{', '}', '?', ':', ';', ',', '*', '%', '^', '!', '=', '<', '>', '+', '-', '&', '|':
R=ken2
CC=golang-dev
https://golang.org/cl/13431046
If a fault happens in malloc, inevitably the next thing that happens
is a deadlock trying to allocate the panic value that says the fault
happened. Stop doing that, two ways.
First, reject panic in malloc just as we reject panic in garbage collection.
Second, runtime.panicstring was using an error implementation
backed by a Go string, so the interface held an allocated *string.
Since the actual errors are C strings, define a new error
implementation backed by a C char*, which needs no indirection
and therefore no allocation.
This second fix will avoid allocation for errors like nil panic derefs
or division by zero, so it is worth doing even though the first fix
should take care of faults during malloc.
Update #6419
R=golang-dev, dvyukov, dave
CC=golang-dev
https://golang.org/cl/13774043
Keeping pointers from the pre-walk phase confuses
the race detection instrumentation.
Fixes#6418.
R=golang-dev, dvyukov, r
CC=golang-dev
https://golang.org/cl/13368057
This is a framework for docs on the subject more than it is
actual docs.
The section header in go/doc.go just says "C", not "C/C++,"
because otherwise godoc doesn't recognize the line as a
section header.
Fixes#5473.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13280050
This eliminates ~75% of the nil checks being emitted,
on all architectures. We can do better, but we need
a bit more general support from the compiler, and
I don't want to do that so close to Go 1.2.
What's here is simple but effective and safe.
A few small code generation cleanups were required
to make the analysis consistent on all systems about
which nil checks are omitted, at least in the test.
Fixes#6019.
R=ken2
CC=golang-dev
https://golang.org/cl/13334052
47ec7a68b1a2 added support for ECDSA ciphersuites but didn't alter the
cipher suite selection to take that into account. Thus Go servers could
try and select an ECDSA cipher suite while only having an RSA
certificate, leading to connection failures.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13239053
In particular document that the Go tool will look for certain
file extensions and compile with them with either the C or the
C++ compiler.
Fixes#6393.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13733043
This interface is required to use the PCDATA interface
implemented in Go 1.2. While initially entirely private, the
FUNCDATA side of the interface has been made public. This
change completes the FUNCDATA/PCDATA interface.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13735043
Hide container symbols like text and etext so that
the individual pieces inside are shown instead.
For example, if text and main.init have the same
address, it was a toss-up which name was printed.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13722046
The code for call site-specific pointer bitmaps was not ready in time,
but the zeroing required without it is too expensive to use by default.
We will have to wait for precise collection of stack frames until Go 1.3.
The precise collection can be re-enabled by
GOEXPERIMENT=precisestack ./all.bash
but that will not be the default for a Go 1.2 build.
Fixes#6087.
R=golang-dev, jeremyjackins, dan.kortschak, r
CC=golang-dev
https://golang.org/cl/13677045
With TLS 1.2, when sending client certificates the code was omitting
the new (in TLS 1.2) signature and hash fields.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13413050
The uint64 divide function calls _mul64x32 to do a 64x32-bit multiply
and then compares the result against the 64-bit numerator.
If the result is bigger than the numerator, must use the slow path.
Unfortunately, the 64x32 produces a 96-bit product, and only the
low 64 bits were being used in the comparison. Return all 96 bits,
the bottom 64 via the original uint64* pointer, and the top 32
as the function's return value.
Fixes 386 build (broken by ARM division tests).
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13722044
This CL is required for all.bat to work out of the box on
my Windows 8 laptop.
These tests either require the firewall to be turned off
or require the user to be in the Administrators group.
I don't know which.
Alex may follow up with a refinement of the test to
allow them to run if the user is in the Administrators
group.
Fixes#6392.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13421049
Because we can, and because it otherwise might crash
the program if we think we're out of memory.
Fixes#6390.
R=golang-dev, iant, minux.ma
CC=golang-dev
https://golang.org/cl/13345048
The implementation of division in the 5 toolchain is a bit too magical.
Hide the magic from the traceback routines.
Also add a test for the results of the software divide routine.
Fixes#5805.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13239052
The kernel implementation of the fast system call path,
the one invoked by the SYSCALL instruction, is broken for
restarting system calls. A C program demonstrating this is below.
Change the system calls to use INT $0x80 instead, because
that (perhaps slightly slower) system call path actually works.
I filed http://www.freebsd.org/cgi/query-pr.cgi?pr=182161.
The C program demonstrating that it is FreeBSD's fault is below.
It reports the same "Bad address" failures from wait.
#include <sys/time.h>
#include <sys/signal.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
static void handler(int);
static void* looper(void*);
int
main(void)
{
int i;
struct sigaction sa;
pthread_cond_t cond;
pthread_mutex_t mu;
memset(&sa, 0, sizeof sa);
sa.sa_handler = handler;
sa.sa_flags = SA_RESTART;
memset(&sa.sa_mask, 0xff, sizeof sa.sa_mask);
sigaction(SIGCHLD, &sa, 0);
for(i=0; i<2; i++)
pthread_create(0, 0, looper, 0);
pthread_mutex_init(&mu, 0);
pthread_mutex_lock(&mu);
pthread_cond_init(&cond, 0);
for(;;)
pthread_cond_wait(&cond, &mu);
return 0;
}
static void
handler(int sig)
{
}
int
mywait4(int pid, int *stat, int options, struct rusage *rusage)
{
int result;
asm("movq %%rcx, %%r10; syscall"
: "=a" (result)
: "a" (7),
"D" (pid),
"S" (stat),
"d" (options),
"c" (rusage));
}
static void*
looper(void *v)
{
int pid, stat, out;
struct rusage rusage;
for(;;) {
if((pid = fork()) == 0)
_exit(0);
out = mywait4(pid, &stat, 0, &rusage);
if(out != pid) {
printf("wait4 returned %d\n", out);
}
}
}
Fixes#6372.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13582047
Previously, fields of type chan or func caused an error.
Now we just treat them like unexported fields and ignore them.
This makes it easier to guarantee long-term compatibilty since
a substructure from another package cannot break gob
encoding by adding a func or chan field.
Fixes#6071
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13693043
The test 'gp == m->curg' is not valid on Windows,
because the goroutine being profiled is not from the
current m.
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13718043
Fake types describing the internal structure of hashmaps are
generated for use by precise GC.
Generating hash and eq functions for these fake types slows down
the build and wastes space: the go tool binary size is 13MB
instead of 12MB, and the package size on amd64 is 48.7MB instead
of 45.3MB.
R=golang-dev, daniel.morsing, r, khr, rsc, iant
CC=golang-dev
https://golang.org/cl/13698043
Because profiling signals can arrive at any time, we must
handle the case where a profiling signal arrives halfway
through a goroutine switch. Luckily, although there is much
to think through, very little needs to change.
Fixes#6000.
Fixes#6015.
R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/13421048
Fixes#6355.
zerrors_linux_{386,amd64,arm}.go were regenerated using mkerrors.sh but I opted to add the three TC.*FLUSH lines by hand to keep the diff smaller and avoid problems with the API checker.
I'll check freebsd and darwin, could I ask for help with net/open bsd.
R=mikioh.mikioh, jsing, minux.ma, bradfitz
CC=golang-dev
https://golang.org/cl/13660043
It's too late to change this behavior: it breaks templates with minimized JavaScript.
Makes me sad because this common error can never be caught: "{foo}}".
Three cheers for compatibility.
(Leave in a fix to a broken test.)
R=golang-dev, dsymonds, rsc
CC=golang-dev
https://golang.org/cl/13689043
This reverts CL 13261048. I have just learned that these are
no longer supported on code.google.com (that is, it is impossible
to create them), so there is little reason to add support in
Go 1.2.
Update #5408
R=golang-dev, dave, r
CC=golang-dev
https://golang.org/cl/13317046
Bug #1:
Issue 5406 identified an interesting case:
defer iface.M()
may end up calling a wrapper that copies an indirect receiver
from the iface value and then calls the real M method. That's
two calls down, not just one, and so recover() == nil always
in the real M method, even during a panic.
[For the purposes of this entire discussion, a wrapper's
implementation is a function containing an ordinary call, not
the optimized tail call form that is somtimes possible. The
tail call does not create a second frame, so it is already
handled correctly.]
Fix this bug by introducing g->panicwrap, which counts the
number of bytes on current stack segment that are due to
wrapper calls that should not count against the recover
check. All wrapper functions must now adjust g->panicwrap up
on entry and back down on exit. This adds slightly to their
expense; on the x86 it is a single instruction at entry and
exit; on the ARM it is three. However, the alternative is to
make a call to recover depend on being able to walk the stack,
which I very much want to avoid. We have enough problems
walking the stack for garbage collection and profiling.
Also, if performance is critical in a specific case, it is already
faster to use a pointer receiver and avoid this kind of wrapper
entirely.
Bug #2:
The old code, which did not consider the possibility of two
calls, already contained a check to see if the call had split
its stack and so the panic-created segment was one behind the
current segment. In the wrapper case, both of the two calls
might split their stacks, so the panic-created segment can be
two behind the current segment.
Fix this by propagating the Stktop.panic flag forward during
stack splits instead of looking backward during recover.
Fixes#5406.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13367052
The public key serialization from CreateCertificate is factored out to be
used in MarshalPKIXPublicKey.
Testcode with one P224 ECDSA keypair has been added.
R=golang-dev, agl
CC=agl, golang-dev
https://golang.org/cl/13427044
It was simply a missing error case: when scanning plain text
outside of an action, a right delimiter should be an error.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/13468045
Reduces a number of trials but it still can detect memory leak
when we make blunders in runtime-integarted network poller work,
like just forgetting to call runtime_pollClose in code paths.
Also disables the test on windows/386.
R=alex.brainman, r
CC=golang-dev
https://golang.org/cl/13022046
Pull the stack split generation into its own function.
This will make an upcoming change to fix recover
easier to digest.
R=ken2
CC=golang-dev
https://golang.org/cl/13611044
There is no reason to do this, and it's more work.
««« original CL description
net: make channel-based semaphore depend on receive, not send
R=r, dvyukov
CC=golang-dev
https://golang.org/cl/13348045
»»»
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13632047
There is a cleaner, simpler way.
««« original CL description
cmd/5g, cmd/6g, cmd/8g: faster compilation
Replace linked list walk with memset.
This reduces CPU time taken by 'go install -a std' by ~10%.
Before:
real user sys
0m23.561s 0m16.625s 0m5.848s
0m23.766s 0m16.624s 0m5.846s
0m23.742s 0m16.621s 0m5.868s
after:
0m22.714s 0m14.858s 0m6.138s
0m22.644s 0m14.875s 0m6.120s
0m22.604s 0m14.854s 0m6.081s
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13084043
»»»
TBR=dvyukov
CC=golang-dev
https://golang.org/cl/13352049
Asking about runtime/cgo when CgoEnabled=false now correctly
returns an error from build.Import (specifically, NoGoError), because
there are no buildable Go files in that directory.
The API tool was depending on it returning a package with no Go
files instead. Correct that assumption.
Fixes all.bash on local machines.
(Dashboard appears not to be running the api tool at all.)
Update #6124
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13385046
It was never going to last.
««« original CL description
cmd/api: break the builds
There is some question about whether the api tool is
running on Windows (see issue 6124), and now I'm
starting to question whether it runs on any of the builders,
since both darwin/amd64 and linux/amd64 are crashing for me
in the api tool due to a recent cgo-related change, and yet
the dashboard is happy.
If the dashboard is still happy after this CL, we have a problem.
Update #6124
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13632053
»»»
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13474045
There is some question about whether the api tool is
running on Windows (see issue 6124), and now I'm
starting to question whether it runs on any of the builders,
since both darwin/amd64 and linux/amd64 are crashing for me
in the api tool due to a recent cgo-related change, and yet
the dashboard is happy.
If the dashboard is still happy after this CL, we have a problem.
Update #6124
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13632053
args is useful for printing tracebacks.
frame is not necessary anymore, but we might some day
get back to functions where the frame size does not vary
by program counter, and if so we'll need it. Avoid needing
to introduce a new struct format later by keeping it now.
Fixes#5907.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13632051
The old test for "no Go files" was p.Name == "", meaning we never
saw a Go package statement. That test fails if there are cgo files
that we parsed (and recorded the package name) but then chose
not to use (because cgo is not available).
Test the actual file lists instead.
Fixes#6078.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13661043
The units example is nice but is covered by the Lucent
license, which may be a concern for some people making a
commercial source code distribution of Go.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13283045
The various throwing > 0 finish a change started
in a previous CL, which sets throwing = -1 to mean
"don't show the internals". That gets set during the
"all goroutines are asleep - deadlock!" crash, and it
should also be set during any other expected crash
that does not indicate a problem within the runtime.
Most runtime.throw do indicate a problem within the
runtime, however, so we should be able to enumerate
the ones that should be silent. The goroutine sleeping
deadlock is the only one I can think of.
Update #5139
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13662043
Otherwise, if panic starts running deferred functions,
the code that panicked appears to be calling those
functions directly, which is not the case and can be
confusing.
For example:
main.Two()
/Users/rsc/x.go:12 +0x2a
runtime.panic(0x20dc0, 0x2100cc010)
/Users/rsc/g/go/src/pkg/runtime/panic.c:248 +0x106
main.One()
/Users/rsc/x.go:8 +0x55
This makes clear(er) that main.Two is being called during
a panic, not as a direct call from main.One.
Fixes#5832.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13302051
getaddrinfo is supposed to set errno when it returns
EAI_SYSTEM, but sometimes it does not.
Fixes#6232.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13532045
This allows us to make two changes:
1. Force the argument type to be size_t, even on broken
systems that declare malloc to take a ulong.
2. Call runtime.throw if malloc fails.
(That is, the program crashes; it does not panic.)
Fixes#3403.
Fixes#5926.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13413047
This CL adds minimal support of Happy Eyeballs-like TCP connection
setup to Dialer API. Happy Eyeballs and derivation techniques are
described in the following:
- Happy Eyeballs: Success with Dual-Stack Hosts
http://tools.ietf.org/html/rfc6555
- Analysing Dual Stack Behaviour and IPv6 Quality
http://www.potaroo.net/presentations/2012-04-17-dual-stack-quality.pdf
Usually, the techniques consist of three components below.
- DNS query racers, that run A and AAAA queries in parallel or series
- A short list of destination addresses
- TCP SYN racers, that run IPv4 and IPv6 transport in parallel or series
This CL implements only the latter two. The existing DNS query
component gathers together A and AAAA records in series, so we don't
touch it here. This CL just uses extended resolveInternetAddr and makes
it possible to run multiple Dial racers in parallel.
For example, when the given destination is a DNS name and the name has
multiple address family A and AAAA records, and it happens on the TCP
wildcard network "tcp" with DualStack=true like the following:
(&net.Dialer{DualStack: true}).Dial("tcp", "www.example.com:80")
The function will return a first established connection either TCP over
IPv4 or TCP over IPv6, and close the other connection internally.
Fixes#3610.
Fixes#5267.
Benchmark results on freebsd/amd64 virtual machine, tip vs. tip+12416043:
benchmark old ns/op new ns/op delta
BenchmarkTCP4OneShot 50696 52141 +2.85%
BenchmarkTCP4OneShotTimeout 65775 66426 +0.99%
BenchmarkTCP4Persistent 10986 10457 -4.82%
BenchmarkTCP4PersistentTimeout 11207 10445 -6.80%
BenchmarkTCP6OneShot 62009 63718 +2.76%
BenchmarkTCP6OneShotTimeout 78351 79138 +1.00%
BenchmarkTCP6Persistent 14695 14659 -0.24%
BenchmarkTCP6PersistentTimeout 15032 14646 -2.57%
BenchmarkTCP4ConcurrentReadWrite 7215 6217 -13.83%
BenchmarkTCP6ConcurrentReadWrite 7528 7493 -0.46%
benchmark old allocs new allocs delta
BenchmarkTCP4OneShot 36 36 0.00%
BenchmarkTCP4OneShotTimeout 36 36 0.00%
BenchmarkTCP4Persistent 0 0 n/a%
BenchmarkTCP4PersistentTimeout 0 0 n/a%
BenchmarkTCP6OneShot 37 37 0.00%
BenchmarkTCP6OneShotTimeout 37 37 0.00%
BenchmarkTCP6Persistent 0 0 n/a%
BenchmarkTCP6PersistentTimeout 0 0 n/a%
BenchmarkTCP4ConcurrentReadWrite 0 0 n/a%
BenchmarkTCP6ConcurrentReadWrite 0 0 n/a%
benchmark old bytes new bytes delta
BenchmarkTCP4OneShot 2500 2503 0.12%
BenchmarkTCP4OneShotTimeout 2508 2505 -0.12%
BenchmarkTCP4Persistent 0 0 n/a%
BenchmarkTCP4PersistentTimeout 0 0 n/a%
BenchmarkTCP6OneShot 2713 2707 -0.22%
BenchmarkTCP6OneShotTimeout 2722 2720 -0.07%
BenchmarkTCP6Persistent 0 0 n/a%
BenchmarkTCP6PersistentTimeout 0 0 n/a%
BenchmarkTCP4ConcurrentReadWrite 0 0 n/a%
BenchmarkTCP6ConcurrentReadWrite 0 0 n/a%
R=golang-dev, bradfitz, nightlyone, rsc
CC=golang-dev
https://golang.org/cl/12416043
For example, if the pattern is m... there is
no need to look in directories not beginning with m.
Fixes#5214.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/13253049
Add coverage for some uncovered bytes methods. The increase in actual coverage is disapointing small.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13651044
The scan starts at the directory we care about and works
backward to the GOPATH root. The error should say the
original directory name, not the name of the GOPATH root.
Fixes#6175.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13366050
The entry for LEAL/LEAQ in these optabs was listed as having
two data bytes in the y array. In fact they had and expect no data
bytes. However, the general loop expects to be able to look at at
least one data byte, to make sure it is not 0x0f. So give them each
a single data byte set to 0 (not 0x0f).
Since the MOV instructions have the largest optab cases, this
requires growing the size of the data array.
Clang found this bug because the general o->op[z] == 0x0f
test was using z == 22, which was out of bounds.
In practice the next byte in memory was probably not 0x0f
so it wasn't truly broken. But might as well be clean.
Update #5764
R=ken2
CC=golang-dev
https://golang.org/cl/13241050
Fixes cpu subtype check when using external linker which sets the CPU_SUBTYPE_LIB64 bit (1<<31).
Fixes#6197.
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/13248046
For example, if an x_test.go file contains a syntax error,
b.test fails with an error message. But it wasn't printing
the same FAIL line that a build failure later would print.
This makes all the test failures that happen (once we
decide to start running tests) consistently say FAIL.
Fixes#4701.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13431044
A package main binary (that is, a command) being installed
does not mean we can skip the build of the package archive
during a test.
Fixes#3417.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13462046
It was lost when the generic "Notes" support went in.
Had to change the test setup, because it precluded even
being able test multi-line comments, much less multi-paragraph
comments.
Now 'godoc sync/atomic' works correctly again.
Fixes#6135.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13427045
Remove test of whether SWIG shared library is older than
sources--should be covered by test of package file anyhow.
Fixes#5739.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13352046
If using other gdb python scripts loaded before Go's gdb-runtime.py
and that have a different init prototype:
Traceback (most recent call last):
File "/usr/lib/go/src/pkg/runtime/runtime-gdb.py", line 446, in <module>
k()
TypeError: __init__() takes exactly 3 arguments (1 given)
The problem is that gdb keeps all python scripts in the same namespace,
so vars() contains them. To avoid that, load helpers one by one.
R=iant, rsc
CC=gobot, golang-dev
https://golang.org/cl/9752044
Various compilers complain about the macro expansion not
being used. I fixed a few yesterday. More today.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13643044
Before CL 7065067 calling Next on an element returned either the
next/prev element or nil was returned. After the CL if an element
was not part of a list e.Next() and e.Prev() will panic. This CL
returns to the documented behavior, that Next/Prev returns the
next/prev list element or nil.
Fixes#6349.
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/13234051
Bug3486 tried to walk the entire file tree, but other tests might
be creating and removing files in that tree. In particular, package os
creates and removes files in the os directory, and issue 5863
reports failures due to seeing those files appear and then disappear.
Change the test to walk just the test tree, which should not be
changing.
Fixes#5863.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13467045
This will bring in the C++ standard library without requiring
any special #cgo LDFLAGS options.
When using gccgo, just add -lstdc++ to link line; this should
do no harm if it is not needed.
No tests, since we don't want to assume a C++ compiler.
Update #5629
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/13394045
If you thought gcc -ansi -pedantic was pedantic, just wait
until you meet clang -fsanitize=undefined.
I think this addresses all the reported "errors", but we'll
need another run to be sure.
all.bash still passes.
Update #5764
Dave, can you please try again?
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13334049
The code in question is trying to print a nice error message
when a Go EABI binary runs on an OABI machine.
Unfortunately, the only way to do that is to use
ARM Thumb instructions, which we otherwise don't use.
There exist ARM EABI machines that do not support Thumb.
We could run on them if not for this OABI check, so disable it.
Fixes#5685.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13234050
Cannot happen when using the go command, but help
people running commands by hand or with other tools.
Fixes#5888.
R=ken2
CC=golang-dev
https://golang.org/cl/13324048
The huffmanDecoder struct appears to be intented for reuse by calling init a
second time with a second sequence of code lengths. Unfortunately, it can
currently panic if the second sequence of code lengths has a minimum value
greater than 10 due to failure to reinitialize the links table.
This change prevents the panic by resetting the huffmanDecoder struct back to
the struct's zero value at the beginning of the init method if the
huffmanDecoder is being reused (determined by checking if min has been set to a
non-zero value).
Fixes#6255.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13230043
Currently lots of sys allocations are not accounted in any of XxxSys,
including GC bitmap, spans table, GC roots blocks, GC finalizer blocks,
iface table, netpoll descriptors and more. Up to ~20% can unaccounted.
This change introduces 2 new stats: GCSys and OtherSys for GC metadata
and all other misc allocations, respectively.
Also ensures that all XxxSys indeed sum up to Sys. All sys memory allocation
functions require the stat for accounting, so that it's impossible to miss something.
Also fix updating of mcache_sys/inuse, they were not updated after deallocation.
test/bench/garbage/parser before:
Sys 670064344
HeapSys 610271232
StackSys 65536
MSpanSys 14204928
MCacheSys 16384
BuckHashSys 1439992
after:
Sys 670064344
HeapSys 610271232
StackSys 65536
MSpanSys 14188544
MCacheSys 16384
BuckHashSys 3194304
GCSys 39198688
OtherSys 3129656
Fixes#5799.
R=rsc, dave, alex.brainman
CC=golang-dev
https://golang.org/cl/12946043
For some long filenames the USTAR-split code does not work
correctly. It is wrongly assumed that the path would not be too long,
but it is.
The user visible result was that a filename was split, but it still
caused an error.
The cause was a wrongly calculated nlen. In addition I noticed that
at this place it is also seems necessary to check if the prefix will
fit in the 155 chars available for the prefix.
R=dsymonds, rsc
CC=golang-dev
https://golang.org/cl/13300046
Old example referenced global var from multiSorter.Sort and ignored it's argument.
Changed one of example calls to actually pass slice to sort.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13551044
* Sort imports by import path, then import name, then comment. Currently, gofmt sorts only by import path.
* If two imports have the same import path and import name, and one of them has no comment, remove the import with no comment. (See the discussion at issue 4414.)
Based on @rsc's https://golang.org/cl/7231070/Fixes#4414.
R=gri, rsc
CC=golang-dev
https://golang.org/cl/12837044
This message was helpful for pre-Go 1 users updating to Go 1.
That time is past. Now the message is confusing because it
depends on knowing what pre-Go 1 looked like.
Update #4697.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13335051
Make sure we never pass a timer into timerproc with
a negative duration since it will cause other timers
to never expire.
Fixes#5321.
R=golang-dev, minux.ma, remyoudompheng, mikioh.mikioh, r, bradfitz, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/9035047
But keep their case for ease of searching.
They were added recently. We don't want them part of go1.2's API.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13569044
cmd/cc: bv.c imports libc.h twice
When using the Plan 9 compiler, the invocation
#include <../ld/textflag.h>
works for the toolchain, but not for the MACH library.
Module cmd/cc/bv.c includes libc.h and "cc.h", which in
turn also includes libc.h. In the Plan 9 context, this
causes a number of duplicate definitions.
R=golang-dev, rsc, r
CC=golang-dev
https://golang.org/cl/13303047
Flushing after every token negates the point of buffering. A different approach is required.
««« original CL description
encoding/xml: flush buffer after encoding token
R=rsc, bradfitz, adg
CC=golang-dev
https://golang.org/cl/13004046
»»»
R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/13515043
This should have been part of revision 16731:cdedb129e020, but
I missed it. This fixes printing local variables when doing
an external link.
No test because we aren't doing any debug info testing yet.
Fixes#5719.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13464046
DeepEqual caches addresses of compared values
each time it visits addressable values. This is
more expensive than actually comparing them in
the common case of large slices of bytes or integers.
Also add a fast path for slices with identical
underlying array.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13000044
The underlying parse tree is visible in text/template, so it should be visible here.
Done by copying the underlying *parse.Tree up to the top level of the struct, and then making sure it's kept up to date.
Fixes#6318.
R=mikesamuel
CC=golang-dev
https://golang.org/cl/13479044
Based on an old suggestion by rsc, it compares the second
and following arguments to the first.
Unfortunately the code cannot be as pretty as rsc's original
because it doesn't require identical types.
R=golang-dev, dsymonds, adg
CC=golang-dev
https://golang.org/cl/13509046
This CL makes resolveInternetAddr return a list of addresses that
contain a pair of different address family IP addresses if possible,
but doesn't contain any API behavioral changes yet. A simple IP
address selection mechanism for Resolve{TCP,UDP,IP}Addr and Dial API
still prefers IPv4.
This is in preparation for TCP connection setup with fast failover on
dual IP stack node as described in RFC 6555.
Update #3610
Update #5267
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13374043
Update #4805
Add the ability to set an open connection limit.
Fixed case where the Conn finalCloser was being called with db.mu locked.
Added separate benchmarks for each path for Exec and Query.
Replaced slice based idle pool with list based idle pool.
R=bradfitz
CC=golang-dev
https://golang.org/cl/10726044
This change allows people who want to parse or set odd X.509 extensions
to do so without having to add support for them all to the package.
I tried to make it so that only a single member: Extensions would be
needed. However, that would mean detecting when the caller had altered
the contents of it so that parsing and marshaling a certificate
wouldn't ignore all changes to the other members. This ended up being
messy, thus the current design where there are two members: one for
reading and another for writing.
As crypto/x509 adds support for more extensions in the future, the raw
extensions will still be in Extensions for older code that expects it
there. Also, future extensions will be overridden by any raw extensions
added to ExtraExtensions by code that was written before support was
added.
R=golang-dev, r
CC=golang-dev, jpsugar
https://golang.org/cl/12056043
Also introduce BGET2/4, BPUT2/4 as they are widely used.
Slightly improve BGETC/BPUTC implementation.
This gives ~5% CPU time improvement on go install -a -p1 std.
Before:
real user sys
0m23.561s 0m16.625s 0m5.848s
0m23.766s 0m16.624s 0m5.846s
0m23.742s 0m16.621s 0m5.868s
after:
0m22.999s 0m15.841s 0m5.889s
0m22.845s 0m15.808s 0m5.850s
0m22.889s 0m15.832s 0m5.848s
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/12745047
image/color package into their own package. They require some non-
trivial init-time code (interface conversions, currently 40KiB of text)
that would otherwise burden any Go program that imported image/color.
R=r
CC=golang-dev
https://golang.org/cl/13256046
This CL adds a new type addrList that will carry a short list of IP
addresses to dial helper functions in the upcoming CLs.
This is in preparation for TCP connection setup with fast failover on
dual IP stack node as described in RFC 6555.
Update #3610
Update #5267
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13241046
Breaks build, and has a race.
««« original CL description
database/sql: add SetMaxOpenConns
Update #4805
Add the ability to set an open connection limit.
Fixed case where the Conn finalCloser was being called with db.mu locked.
Added seperate benchmarks for each path for Exec and Query.
Replaced slice based idle pool with list based idle pool.
R=bradfitz
CC=golang-dev
https://golang.org/cl/10726044
»»»
R=golang-dev
CC=golang-dev
https://golang.org/cl/13252046
Update #4805
Add the ability to set an open connection limit.
Fixed case where the Conn finalCloser was being called with db.mu locked.
Added seperate benchmarks for each path for Exec and Query.
Replaced slice based idle pool with list based idle pool.
R=bradfitz
CC=golang-dev
https://golang.org/cl/10726044
This CL adds the netaddr interface that will carry a single network
endpoint address or a short list of IP addresses to dial helper
functions in the upcoming CLs.
This is in preparation for TCP connection setup with fast failover on
dual IP stack node as described in RFC 6555.
Update #3610
Update #5267
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13368044
This replaces the mcall frame with the badmcall frame instead of
leaving the mcall frame on the stack and adding the badmcall frame.
Because mcall is no longer on the stack, traceback will now report what
called mcall, which is what we would like to see in this situation.
R=golang-dev, cshapiro
CC=golang-dev
https://golang.org/cl/13012044
Minor. Saw this in a profile at few percent of CPU and was
curious what it was. Improves overall regexp benchmarks
anywhere from 0 to 3%, but they're a pain to run. You need to
run them in isolation for long runs to get stable numbers.
benchmark old ns/op new ns/op delta
BenchmarkEmptyOpContext 537 473 -11.92%
R=golang-dev, crawshaw
CC=golang-dev
https://golang.org/cl/13407043
AES-GCM is the only current TLS ciphersuite that doesn't have
cryptographic weaknesses (RC4), nor major construction issues (CBC mode
ciphers) and has some deployment (i.e. not-CCM).
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13249044
I noticed that this one benchmark in particular was very
noisy. Looking into it, I saw that the table was wrong
and inconsistent with the lines above and below.
R=golang-dev, crawshaw
CC=golang-dev
https://golang.org/cl/13393045
When searching for an allocated bit, flushptrbuf would search
backward in the bitmap word containing the bit of pointer
being looked-up before searching the span. This extra check
was not replicated in markonly which, instead, after not
finding an allocated bit for a pointer would directly look in
the span.
Using statistics generated from godoc, before this change span
lookups were, on average, more common than word lookups. It
was common for markonly to consult spans for one third of its
pointer lookups. With this change in place, what were
previously span lookups are overwhelmingly become by the word
lookups making the total number of span lookups a relatively
small fraction of the whole.
This change also introduces some statistics gathering about
lookups guarded by the CollectStats enum.
R=golang-dev, khr
CC=golang-dev
https://golang.org/cl/13311043
#pragma textflag and #pragma dataflag directives.
Update dataflag directives to use symbols instead of integer constants.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13310043
