Russ Cox [Wed, 7 Nov 2012 20:15:21 +0000 (15:15 -0500)]
cmd/gc: fix escape analysis bug
The code assumed that the only choices were EscNone, EscScope, and EscHeap,
so that it makes sense to set EscScope only if the current setting is EscNone.
Now that we have the many variants of EscReturn, this logic is false, and it was
causing important EscScopes to be ignored in favor of EscReturn.
Dmitriy Vyukov [Wed, 7 Nov 2012 19:59:09 +0000 (23:59 +0400)]
runtime/race: add Windows support
This is copy of https://golang.org/cl/6810080
but sent from another account (dvyukov@gmail.com is not in CONTRIBUTORS).
Roger Peppe [Wed, 7 Nov 2012 15:16:34 +0000 (15:16 +0000)]
crypto/x509: fix DecryptPEMBlock
The current implement can fail when the
block size is not a multiple of 8 bytes.
This CL makes it work, and also checks that the
data is in fact a multiple of the block size.
Russ Cox [Wed, 7 Nov 2012 14:59:19 +0000 (09:59 -0500)]
cmd/gc: annotate local variables with unique ids for inlining
Avoids problems with local declarations shadowing other names.
We write a more explicit form than the incoming program, so there
may be additional type annotations. For example:
int := "hello"
j := 2
would normally turn into
var int string = "hello"
var j int = 2
but the int variable shadows the int type in the second line.
This CL marks all local variables with a per-function sequence number,
so that this would instead be:
Dmitriy Vyukov [Wed, 7 Nov 2012 08:48:58 +0000 (12:48 +0400)]
runtime/race: lazily allocate shadow memory
Currently race detector runtime maps shadow memory eagerly at process startup.
It works poorly on Windows, because Windows requires reservation in swap file
(especially problematic if several Go program runs at the same, each consuming GBs
of memory).
With this change race detector maps shadow memory lazily, so Go runtime must notify
about all new heap memory.
It will help with Windows port, but also eliminates scary 16TB virtual mememory
consumption in top output (which sometimes confuses some monitoring scripts).
Dmitriy Vyukov [Wed, 7 Nov 2012 08:06:27 +0000 (12:06 +0400)]
cmd/gc: racewalk: do not double function calls
Current racewalk transformation looks like:
x := <-makeChan().c
\/\/\/\/\/\/\/\/\/
runtime.raceread(&makeChan().c)
x := <-makeChan().c
and so makeChan() is called twice.
With this CL the transformation looks like:
x := <-makeChan().c
\/\/\/\/\/\/\/\/\/
chan *tmp = &(makeChan().c)
raceread(&*tmp)
x := <-(*tmp)
Fixes #4245.
Péter Surányi [Tue, 6 Nov 2012 20:59:21 +0000 (04:59 +0800)]
cmd/godoc: initialize filesystem and metadata for -url
Unlike when using -http, godoc -url didn't initialize the "filesystem"
and metadata that are used when generating responses. This CL adds this
initialization, so that -url provides the same results as an HTTP
request when using -http.
Dmitriy Vyukov [Tue, 6 Nov 2012 16:54:22 +0000 (20:54 +0400)]
runtime: mark race instrumentation callbacks as nosplitstack
It speedups the race detector somewhat, but also prevents
getcallerpc() from obtaining lessstack().
Dmitriy Vyukov [Tue, 6 Nov 2012 16:11:16 +0000 (20:11 +0400)]
runtime: fix deadlock in parallel for test
The deadlock occurs when another goroutine requests GC
during the test. When wait=true the test expects physical parallelism,
that is, that P goroutines are all active at the same time.
If GC is requested, then part of the goroutines are not scheduled,
so other goroutines deadlock.
With wait=false, goroutines finish parallel for w/o waiting for all
other goroutines.
Fixes #3954.
Dmitriy Vyukov [Tue, 6 Nov 2012 08:09:40 +0000 (12:09 +0400)]
runtime: disable parallel for tests under race detector.
The race detector does not understand ParFor synchronization, because it's implemented in C.
If run with -cpu=2 currently race detector says:
WARNING: DATA RACE
Read by goroutine 5:
runtime_test.TestParForParallel()
src/pkg/runtime/parfor_test.go:118 +0x2e0
testing.tRunner()
src/pkg/testing/testing.go:301 +0x8f
Previous write by goroutine 6:
runtime_test.func·024()
src/pkg/runtime/parfor_test.go:111 +0x52
Rob Pike [Fri, 2 Nov 2012 23:17:34 +0000 (16:17 -0700)]
sort: make return value for 'not found' clearer in docs
It was well-defined but easy to miss that the return value for
"not found" is len(input) not -1 as many expect.
Rémy Oudompheng [Fri, 2 Nov 2012 06:50:59 +0000 (07:50 +0100)]
cmd/5g, cmd/6g: fix out of registers with array indexing.
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.
Russ Cox [Fri, 2 Nov 2012 04:17:21 +0000 (00:17 -0400)]
cmd/gc, cmd/ld: struct field tracking
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
Dmitriy Vyukov [Thu, 1 Nov 2012 18:56:04 +0000 (22:56 +0400)]
cmd/gc: racewalk: fix a bunch of minor issues
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 _.
Robert Griesemer [Thu, 1 Nov 2012 18:23:27 +0000 (11:23 -0700)]
exp/types/staging: filling in more blanks
- 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).
Ian Lance Taylor [Thu, 1 Nov 2012 18:13:50 +0000 (11:13 -0700)]
cmd/go: fixes to gccgo support
* 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.
Dmitriy Vyukov [Thu, 1 Nov 2012 18:11:12 +0000 (22:11 +0400)]
cmd/gc: racewalk: fix instrumentation of ninit lists
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.
Robert Griesemer [Thu, 1 Nov 2012 17:13:48 +0000 (10:13 -0700)]
spec: clarify returns, defer statements, and panics
This is an attempt at making the interaction between
these three constructs clearer. Specifically:
- return statements terminate a function, execute deferred
functions, return to the caller, and then execution
continues after the call
- panic calls terminate a function, execute deferred
functions, return to the caller, and then re-panic
- deferred functions are executed before a function _returns_
to its caller
The hope is that with this change it becomes clear when a
deferred function is executed (when a function returns),
and when it is not (when a program exits).
Nigel Tao [Thu, 1 Nov 2012 00:46:06 +0000 (11:46 +1100)]
image/png: degrade gracefully for palette index values that aren't
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));