Ian Lance Taylor [Sun, 20 Jul 2014 19:25:24 +0000 (12:25 -0700)]
test: avoid "declared but not used" errors in shift1.go
I'm improving gccgo's detection of variables that are only set
but not used, and it triggers additional errors on this code.
The new gccgo errors are correct; gc seems to suppress them
due to the other, expected, errors. This change uses the
variables so that no compiler will complain.
cmd/gc: do not mark PC as pointer on stack
GC thinks that it's an invalid pointer on plan9:
http://build.golang.org/log/f7da638a20544ef7f45e81f23fdbc4875044c296
These benchmarks are important for performance. When compiling the stdlib:
* 77.1% of the calls to sgen (copyfat) are for 16 bytes; another 8.7% are for 24 bytes. (The next most common is 32 bytes, at 5.7%.)
* Over half the calls to clearfat are for 16 or 24 bytes.
encoding/gob: remove unnecessary receivers
Encoder compilation must be enc-independent,
because the resulting program is reused across
different encoders.
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/115860043
This code will cause gcc issuing warnings about unused variable.
This commit use offset of the second return value of
Packages.structType to detect whether the gcc struct is empty,
and if it's directly invoke the C function instead of writing an
unused code.
LGTM=dave, minux
R=golang-codereviews, iant, minux, dave
CC=golang-codereviews
https://golang.org/cl/109640045
This code will cause gcc issuing warnings about unused variable.
This commit use offset of the second return value of
Packages.structType to detect whether the gcc struct is empty,
and if it's directly invoke the C function instead of writing an
unused code.
LGTM=dave, minux
R=golang-codereviews, iant, minux, dave
CC=golang-codereviews
https://golang.org/cl/109640045
««« original CL description
runtime: stack allocator, separate from mallocgc
In order to move malloc to Go, we need to have a
separate stack allocator. If we run out of stack
during malloc, malloc will not be available
to allocate a new stack.
Stacks are the last remaining FlagNoGC objects in the
GC heap. Once they are out, we can get rid of the
distinction between the allocated/blockboundary bits.
(This will be in a separate change.)
runtime: improve select benchmarks
1. Add select on sync channels benchmark.
2. Make channels in BenchmarkSelectNonblock shared.
With GOMAXPROCS=1 it is the same, but with GOMAXPROCS>1
it becomes a more interesting benchmark.
Previously we had a bitmap to check whether or not a byte
appears in a string should be replaced. But we don't actually
need a separate bitmap for that purpose. Removing the bitmap
makes the code simpler.
os: Separate windows from posix. Implement windows support.
path/filepath: Use the same implementation as other platforms
syscall: Add/rework new APIs for Windows
"archive/tar: reuse temporary buffer in writeHeader" introduced a
change which was supposed to help lower the number of allocations from
512 bytes for every call to writeHeader. This change broke the writing
of PAX headers.
writeHeader calls writePAXHeader and writePAXHeader calls writeHeader
again. writeHeader will end up writing the PAX header twice.
example broken header:
PaxHeaders.4007/NetLock_Arany_=Class_Gold=_Ftanstvny.crt0000000000000000000000000000007112301216634021512 xustar0000000000000000
PaxHeaders.4007/NetLock_Arany_=Class_Gold=_Ftanstvny.crt0000000000000000000000000000007112301216634021512 xustar0000000000000000
example correct header:
PaxHeaders.4290/NetLock_Arany_=Class_Gold=_Ftanstvny.crt0000000000000000000000000000007112301216634021516 xustar0000000000000000 0100644000000000000000000000270412301216634007250 0ustar0000000000000000
This commit adds a dedicated buffer for pax headers to the Writer
struct. This change increases the size of the struct by 512 bytes, but
allows tar/writer to avoid allocating 512 bytes for all written
headers and it avoids allocating 512 more bytes for pax headers.
As written, the ! applies before the &1.
This would crash writing out missing pcdata tables
if we ever used non-contiguous IDs in a function.
We don't, but fix anyway.
Keith Randall [Wed, 16 Jul 2014 21:16:19 +0000 (14:16 -0700)]
runtime: convert map implementation to Go.
It's a bit slower, but not painfully so. There is still room for
improvement (saving space so we can use nosplit, and removing the
requirement for hash/eq stubs).
Rob Pike [Wed, 16 Jul 2014 18:26:50 +0000 (18:26 +0000)]
cmd/ld: use count, not upper bound, in type of array
DWARF says only one is necessary.
The count is preferable because it admits 0-length arrays.
Update debug/dwarf to handle either form.
runtime: make a test more robust
The issue is discovered during testing of a change to runtime.
Even if it is unlikely to happen, the comment can safe an hour
next person who hits it.
runtime: refactor routines for stopping, running goroutine from m
This CL adds 'dropg', which is called to drop the association
between m and its current goroutine, and it makes schedule
handle locked goroutines correctly, instead of requiring all
callers of schedule to do that.
The effect is that if you want to take over an m for, say,
garbage collection work while still allowing the current g
to run on some other m, you can do an mcall to a function
that is:
// dissociate gp
dropg();
gp->status = Gwaiting; // for ready
// put gp on run queue for others to find
runtime·ready(gp);
/* ... do other work here ... */
// done with m, let it run goroutines again
schedule();
Before this CL, the dropg() body had to be written explicitly,
and the check for lockedg before schedule had to be
written explicitly too, both of which make the code a bit
more fragile than it needs to be.
Robert Griesemer [Mon, 14 Jul 2014 22:08:09 +0000 (15:08 -0700)]
spec: permit "for range x" (no index variables)
This is a fully backward-compatible language change.
There are not a lot of cases in the std library, but
there are some. Arguably this makes the syntax a bit
more regular - any trailing index variable that is _
can be left away, and there's some analogy to type
switches where the temporary can be left away.
Implementation-wise the change should be trivial as
it can be done completely syntactically. For instance,
the respective change in go/parser is a dozen lines
(see https://golang.org/cl/112970044 ).
Fixes #6102.
LGTM=iant, r, rsc
R=r, rsc, iant, ken
CC=golang-codereviews
https://golang.org/cl/104680043
Rob Pike [Fri, 11 Jul 2014 15:16:00 +0000 (15:16 +0000)]
ld: change DWARF output for structs
The debug/dwarf package cannot parse the format generated here,
but the format can be changed so it does.
After this edit, tweaking the expression defining the offset
of a struct field, the dwarf package can parse the tables (again?).
Pietro Gagliardi [Thu, 10 Jul 2014 19:44:40 +0000 (12:44 -0700)]
debug/elf: add (*File).DynamicSymbols, ErrNoSymbols, and tests for (*File).Symbols and (*File).DynamicSymbols, and formalize symbol order.
Added a complement to (*File).Symbols for the dynamic symbol table.
Would be useful, for instance, if seraching for certain shared objects
compatible with certain libraries (for instance, LADSPA requires an
exported symbol "ladspa_descriptor").
Added a variable ErrNoSymbols that canonicalizes a return from
(*File).Symbols and (*File).DyanmicSymbols if the file has no symbols.
Added tests for both (*File).Symbols and (*File).DynamicSymbols;
there was never a test for (*File).Symbols at all. A small C program using
libelf, included in the test data, was used to produce the golden
symbols to compare against.
As part of the requirements for testing, (*File).Symbols and (*File).DynamicSymbols now document the order in which the symbol tables are returned (in the order the symbols appear in the file).
runtime: grow heap by 64K instead of 128K
When we've switched to 8K pages,
heap started to grow by 128K instead of 64K,
because it was implicitly assuming that pages are 4K.
Fix that and make the code more robust.
debug/plan9obj, cmd/addr2line: on Plan 9 use a.out header
size instead of abusing text symbol
cmd/addr2line needs to know the virtual address of the start
of the text segment (load address plus header size). For
this, it used the text symbol added by the linker. This is
wrong on amd64. Header size is 40 bytes, not 32 like on 386
and arm. Function alignment is 16 bytes causing text to be
at 0x200030.
debug/plan9obj now exports both the load address and the
header size; cmd/addr2line uses this new information and
doesn't rely on text anymore.
NetlinkRIB is currently allocating a page sized slice of bytes in a
for loop and it's also calling Getpagesize() in the same for loop.
This CL changes NetlinkRIB to preallocate the page sized slice of
bytes before reaching the for loop. This reduces memory allocations
and lowers the number of calls to Getpagesize() to 1 per NetlinkRIB
call.
This CL reduces the allocated memory from 141.5 MB down to 52 MB in
a test.
LGTM=crawshaw, dave
R=dave, dsymonds, crawshaw
CC=bradfitz, dsymonds, golang-codereviews
https://golang.org/cl/110920043
After this change, the panic is replaced by a message:
$ go build -o out ...doesntexist
warning: "...doesntexist" matched no packages
no packages to build
The motivation to return 1 exit error code is to allow -o flag
to be used to guarantee that the output binary is written to
when exit status is 0. If someone uses an import path pattern
to specify a single package and suddenly that matches no packages,
it's better to return exit code 1 instead of silently doing nothing.
This is consistent with the case when -o flag is given and multiple
packages are matched.
It's also somewhat consistent with the current behavior with the
panic, except that gave return code 2. But it's similar in
that it's also non-zero (indicating failure).
I've changed the language to be similar to output of go test
when an import path pattern matches no packages (it also has a return status of
1):
$ go test ...doesntexist
warning: "...doesntexist" matched no packages
no packages to test