Keep track of the outargs size needed at each call.
Compute the size of the outargs section of the stack frame. It's just
the max of the outargs size at all the callsites in the function.
Keith Randall [Tue, 14 Jul 2015 06:52:59 +0000 (23:52 -0700)]
[dev.ssa] cmd/compile/internal/ssa: ensure Phi ops are scheduled first
Phi ops should always be scheduled first. They have the semantics
of all happening simultaneously at the start of the block. The regalloc
phase assumes all the phis will appear first.
[dev.ssa] cmd/compile/ssa: handle nested dead blocks
removePredecessor can change which blocks are live.
However, it cannot remove dead blocks from the function's
slice of blocks because removePredecessor may have been
called from within a function doing a walk of the blocks.
CL 11879 did not handle this correctly and broke the build.
To fix this, mark the block as dead but leave its actual
removal for a deadcode pass. Blocks that are dead must have
no successors, predecessors, values, or control values,
so they will generally be ignored by other passes.
To be safe, we add a deadcode pass after the opt pass,
which is the only other pass that calls removePredecessor.
Two alternatives that I considered and discarded:
(1) Make all call sites aware of the fact that removePrecessor
might make arbitrary changes to the list of blocks. This
will needlessly complicate callers.
(2) Handle the things that can go wrong in practice when
we encounter a dead-but-not-removed block. CL 11930 takes
this approach (and the tests are stolen from that CL).
However, this is just patching over the problem.
Todd Neal [Fri, 26 Jun 2015 04:13:57 +0000 (23:13 -0500)]
[dev.ssa] cmd/compile/ssa: dominator tests and benchmarks
This change has some tests verifying functionality and an assortment of
benchmarks of various block lists. It modifies NewBlock to allocate in
contiguous blocks improving the performance of intersect() for extremely
large graphs by 30-40%.
The removal of if false { ... } blocks in the opt
pass exposed that removePredecessor needed
to do more cleaning, on pain of failing later
consistency checks.
Change-Id: I45d4ff7e1f7f1486fdd99f867867ce6ea006a288
Reviewed-on: https://go-review.googlesource.com/11879 Reviewed-by: Keith Randall <khr@golang.org>
Alan Donovan [Tue, 30 Jun 2015 19:07:20 +0000 (15:07 -0400)]
go/types: change {Type,Object,Selection}String to accept a Qualifier function
The optional Qualifier function determines what prefix to attach to
package-level names, enabling clients to qualify packages in different
ways, for example, using only the package name instead of its complete
path, or using the locally appropriate name for package given a set of
(possibly renaming) imports.
Prior to this change, clients wanting this behavior had to copy
hundreds of lines of complex printing logic.
Fun fact: (*types.Package).Path and (*types.Package).Name are valid
Qualifier functions.
We provide the RelativeTo helper function to create Qualifiers so that
the old behavior remains a one-liner.
Fixes golang/go#11133
This CL is a copy of https://go-review.googlesource.com/#/c/11692/
to the golang.org/x/tools repository.
Change-Id: I26d0f3644d077a26bfe350989f9c545f018eefbf
Reviewed-on: https://go-review.googlesource.com/11790 Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Russ Cox [Mon, 29 Jun 2015 17:50:30 +0000 (13:50 -0400)]
cmd/compile: allow linker to drop string headers when not needed
Compiling a simple file containing a slice of 100,000 strings,
the size of the resulting binary dropped from 5,896,224 bytes
to 3,495,968 bytes, which is the expected 2,400,000 bytes,
give or take.
Brad Fitzpatrick [Tue, 30 Jun 2015 16:22:41 +0000 (09:22 -0700)]
net/textproto: don't treat spaces as hyphens in header keys
This was originally done in https://codereview.appspot.com/5690059
(Feb 2012) to deal with bad response headers coming back from webcams,
but it presents a potential security problem with HTTP request
smuggling for request headers containing "Content Length" instead of
"Content-Length".
Part of overall HTTP hardening for request smuggling. See RFC 7230.
Dmitry Vyukov [Tue, 30 Jun 2015 12:09:41 +0000 (14:09 +0200)]
cmd/trace: sort procs
If you have more than 10 procs, then currently they are sorted alphabetically as
0, 10, 11, ..., 19, 2, 20, ...
Assign explicit order to procs so that they are sorted numerically.
Russ Cox [Tue, 30 Jun 2015 15:28:29 +0000 (11:28 -0400)]
net/url: only record RawPath when it is needed
RawPath is a hint to the desired encoding of Path.
It is ignored when it is not a valid encoding of Path,
such as when Path has been changed but RawPath has not.
It is not ignored but also not useful when it matches
the url package's natural choice of encoding.
In this latter case, set it to the empty string.
This should help drive home the point that clients
cannot in general depend on it being present and
that they should use the EncodedPath method instead.
This also reduces the impact of the change on tests,
especially tests that use reflect.DeepEqual on parsed URLs.
Roger Peppe [Mon, 29 Jun 2015 11:36:48 +0000 (12:36 +0100)]
encoding/xml: fix xmlns= behavior
When an xmlns="..." attribute was explicitly generated,
it was being ignored because the name space on the
attribute was assumed to have been explicitly set (to the empty
name space) and it's not possible to have an element in the
empty name space when there is a non-empty name space set.
We fix this by recording when a default name space has been
explicitly set and setting the name space of the element to that
so printer.defineNS can do its work correctly.
We do not attempt to add our own xmlns="..." attribute
when one is explicitly set.
We also add tests for EncodeElement, as that's the only way
to attain coverage of some of the changed behaviour.
Some other test coverage is also increased, although
more work remains to be done in this area.
This change was jointly developed with Martin Hilton (mhilton on github).
Aaron Jacobs [Mon, 29 Jun 2015 00:07:31 +0000 (10:07 +1000)]
net/http: add a Request.Cancel channel.
This allows for "race free" cancellation, in the sense discussed in
issue #11013: in contrast to Transport.CancelRequest, the cancellation
will not be lost if the user cancels before the request is put into the
transport's internal map.
Russ Cox [Mon, 29 Jun 2015 15:53:51 +0000 (11:53 -0400)]
path/filepath: document and test behavior of SkipDir on files
This behavior is not what we might have designed from the start,
but it has been present since Go 1. Rather than make a visible
behavioral change that might cause programs to work differently
in Go ≤1.4 vs Go ≥1.5, document what SkipDir on a non-directory
has always meant. If code doesn't want this meaning, it is easy
enough not to return SkipDir on non-directories.
Russ Cox [Mon, 29 Jun 2015 17:12:10 +0000 (13:12 -0400)]
cmd/link: fix -s with external linking
This code used to only be run for ELF, with the predictable
result that using -s with external linking broke on Windows and OS X.
Moving it here should fix Windows and does fix OS X.
CL 10835 also claims to fix the crash on Windows.
I don't know whether it does so correctly, but regardless,
this CL should make that one a no-op.
Fixes #10254.
Change-Id: I2e7b45ab0c28568ddbb1b50581dcc157ae0e7ffe
Reviewed-on: https://go-review.googlesource.com/11695 Reviewed-by: David Crawshaw <crawshaw@golang.org>
Adam Langley [Sat, 27 Jun 2015 21:50:39 +0000 (14:50 -0700)]
crypto/rsa: check for primes ≤ 1 in Validate
Change 7c7126cfeb82894229b9c3d5109e4b04e6cfde0c removed the primality
checking in Validate to save CPU time. That check happened to be
filtering out private keys with primes that were zero or one. Without
that filtering, such primes cause a panic when trying to use such a
private key.
This change specifically checks for and rejects primes ≤ 1 in Validate.
Russ Cox [Mon, 29 Jun 2015 02:26:35 +0000 (22:26 -0400)]
cmd/link: record missing pcdata tables correctly
The old code was recording the current table output offset,
so the table from the next function would be used instead of
the runtime realizing that there was no table at all.
Add debug constant in runtime to check this for every function
at startup. It's too expensive to do that by default, but we can
do the last five functions. The end of the table is usually where
the C symbols end up, so that's where the problems typically are.
Austin Clements [Fri, 26 Jun 2015 17:56:58 +0000 (13:56 -0400)]
runtime: reset mark state before checkmark and gctrace=2 mark
Currently we fail to reset the live heap accounting state before the
checkmark mark and before the gctrace=2 extra mark. As a result, if
either are enabled, at the end of GC it thinks there are 0 bytes of
live heap, which causes the GC controller to initiate a new GC
immediately, regardless of the true heap size.
Fix this by factoring this state reset into a function and calling it
before all three possible marks.
This function should be merged with gcResetGState, but doing so
requires some additional cleanup, so it will wait for after the
freeze. Filed #11427 for this cleanup.
Austin Clements [Mon, 22 Jun 2015 14:24:50 +0000 (10:24 -0400)]
runtime: don't free stack spans during GC
Memory for stacks is manually managed by the runtime and, currently
(with one exception) we free stack spans immediately when the last
stack on a span is freed. However, the garbage collector assumes that
spans can never transition from non-free to free during scan or mark.
This disagreement makes it possible for the garbage collector to mark
uninitialized objects and is blocking us from re-enabling the bad
pointer test in the garbage collector (issue #9880).
For example, the following sequence will result in marking an
uninitialized object:
1. scanobject loads a pointer slot out of the object it's scanning.
This happens to be one of the special pointers from the heap into a
stack. Call the pointer p and suppose it points into X's stack.
2. X, running on another thread, grows its stack and frees its old
stack.
3. The old stack happens to be large or was the last stack in its
span, so X frees this span, setting it to state _MSpanFree.
4. The span gets reused as a heap span.
5. scanobject calls heapBitsForObject, which loads the span containing
p, which is now in state _MSpanInUse, but doesn't necessarily have
an object at p. The not-object at p gets marked, and at this point
all sorts of things can go wrong.
We already have a partial solution to this. When shrinking a stack, we
put the old stack on a queue to be freed at the end of garbage
collection. This was done to address exactly this problem, but wasn't
a complete solution.
This commit generalizes this solution to both shrinking and growing
stacks. For stacks that fit in the stack pool, we simply don't free
the span, even if its reference count reaches zero. It's fine to reuse
the span for other stacks, and this enables that. At the end of GC, we
sweep for cached stack spans with a zero reference count and free
them. For larger stacks, we simply queue the stack span to be freed at
the end of GC. Ideally, we would reuse these large stack spans the way
we can small stack spans, but that's a more invasive change that will
have to wait until after the freeze.
Austin Clements [Thu, 25 Jun 2015 16:24:44 +0000 (12:24 -0400)]
runtime: remove unused _GCsweep state
We don't use this state. _GCoff means we're sweeping in the
background. This makes it clear in the next commit that _GCoff and
only _GCoff means sweeping.
Russ Cox [Mon, 29 Jun 2015 03:04:05 +0000 (23:04 -0400)]
cmd/cgo: fix a problem with 'go build -compiler gccgo'
Port of https://golang.org/cl/154360045 to Git.
Original author is Xia Bin <snyh@snyh.org> (already a contributor).
Fixes #8945.
Change-Id: I28bcaf3348794202ca59fbc3466bd7b9670030e4
Reviewed-on: https://go-review.googlesource.com/11658 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Austin Clements [Wed, 24 Jun 2015 21:13:24 +0000 (17:13 -0400)]
runtime: always clear stack barriers on G exit
Currently the runtime fails to clear a G's stack barriers in gfput if
the G's stack allocation is _FixedStack bytes. This causes the runtime
to panic if the following sequence of events happens:
1) The runtime installs stack barriers on a G.
2) The G exits by calling runtime.Goexit. Since this does not
necessarily return through the stack barriers installed on the G,
there may still be untriggered stack barriers left on the G's stack
in recorded in g.stkbar.
3) The runtime calls gfput to add the exiting G to the free pool. If
the G's stack allocation is _FixedStack bytes, we fail to clear
g.stkbar.
4) A new G starts and allocates the G that was just added to the free
pool.
5) The new G begins to execute and overwrites the stack slots that had
stack barriers in them.
6) The garbage collector enters mark termination, attempts to remove
stack barriers from the new G, and finds that they've been
overwritten.
Fix this by clearing the stack barriers in gfput in the case where it
reuses the stack.
Rob Pike [Sat, 27 Jun 2015 01:07:30 +0000 (11:07 +1000)]
fmt: restore padding for %x on byte slices and strings
Also improve the documentation. A prior fix in this release
changed the properties for empty strings and slices, incorrectly.
Previous behavior is now restored and better documented.
Add lots of tests.
The behavior is that when using a string-like format (%s %q %x %X)
a byte slice is equivalent to a string, and printed as a unit. The padding
applies to the entire object. (The space and sharp flags apply
elementwise.)
Brad Fitzpatrick [Sat, 27 Jun 2015 03:51:13 +0000 (20:51 -0700)]
net/http: fix now-flaky TransportAndServerSharedBodyRace test
TestTransportAndServerSharedBodyRace got flaky after
issue #9662 was fixed by https://golang.org/cl/11412, which made
servers hang up on clients when a Handler stopped reading its body
early.
This test was affected by a race between the the two goroutines in the
test both only reading part of the request, which was an unnecessary
detail for what the test was trying to test (concurrent Read/Close
races on an *http.body)
Also remove an unused remnant from an old test from which this one was
derived. And make the test not deadlock when it fails. (which was why
the test was showing up as 2m timeouts on the dashboard)
[dev.ssa] cmd/compile/ssa: refine type equality in cse
The correct way to compare gc.Types is Eqtype,
rather than pointer equality.
Introduce an Equal method for ssa.Type to allow
us to use it.
In the cse pass, use a type's string to build
the coarse partition, and then use Type.Equal
during refinement.
This lets the cse pass do a better job.
In the ~20% of the standard library that SSA
can compile, the number of common subexpressions
recognized by the cse pass increases from
27,550 to 32,199 (+17%). The number of nil checks
eliminated increases from 75 to 115 (+50%).
Change-Id: I0bdbfcf613ca6bc2ec987eb19b6b1217b51f3008
Reviewed-on: https://go-review.googlesource.com/11451 Reviewed-by: Keith Randall <khr@golang.org>
Keith Randall [Sat, 27 Jun 2015 19:57:06 +0000 (12:57 -0700)]
cmd/link/internal/ld: exclude only real container symbols from symtab
It looks like the test for whether symbols contain subsymbols is wrong.
In particular, symbols in C libraries are mistakenly considered container
symbols.
Fix the test so only symbols which actually have a subsymbol
are excluded from the symtab. When linking cgo programs the list
of containers is small, something like:
Adam Langley [Sun, 14 Jun 2015 17:48:13 +0000 (10:48 -0700)]
encoding/asn1: be stricter by reserialising parsed times.
The time package does normalisation of times: for example day zero is
converted to the last day of the previous month and the 31st of February
is moved into March etc. This makes the ASN.1 parsing a little
worryingly lax.
This change causes the parser to reserialise parsed times to ensure that
they round-trip correctly and thus were not normalised.
Alex Brainman [Fri, 22 May 2015 00:58:57 +0000 (10:58 +1000)]
runtime: store syscall parameters in m not on stack
Stack can move during callback, so libcall struct cannot be stored on stack.
asmstdcall updates return values and errno in libcall struct parameter, but
these could be at different location when callback returns.
Store these in m, so they are not affected by GC.