Austin Clements [Wed, 19 Nov 2014 19:56:49 +0000 (14:56 -0500)]
[dev.cc] runtime: add explicit siginfo.si_addr field
struct siginfo_t's si_addr field is part of a union.
Previously, we represented this union in Go using an opaque
byte array and accessed the si_addr field using unsafe (and
wrong on 386 and arm!) pointer arithmetic. Since si_addr is
the only field we use from this union, this replaces the
opaque byte array with an explicit declaration of the si_addr
field and accesses it directly.
Austin Clements [Wed, 19 Nov 2014 19:24:41 +0000 (14:24 -0500)]
[dev.cc] runtime: decode power64 branch instructions the way the CPU does
Previously, this used the top 8 bits of an instruction as a
sort-of opcode and ignored the top two bits of the relative
PC. This worked because these jumps are always negative and
never big enough for the top two bits of the relative PC (also
the bottom 2 bits of the sort-of opcode) to be anything other
than 0b11, but the code is confusing because it doesn't match
the actual structure of the instruction.
Instead, use the real 6 bit opcode and use all 24 bits of
relative PC.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/179960043
Austin Clements [Wed, 19 Nov 2014 16:30:58 +0000 (11:30 -0500)]
[dev.cc] runtime: allow more address bits in lfstack on Power64
Previously, lfstack assumed Linux limited user space addresses
to 43 bits on Power64 based on a paper from 2001. It turns
out the limit is now 46 bits, so lfstack was truncating
pointers.
Raise the limit to 48 bits (for some future proofing and to
make it match amd64) and add a self-test that will fail in a
useful way if ever unpack(pack(x)) != x.
With this change, dev.cc passes all.bash on power64le.
Austin Clements [Tue, 18 Nov 2014 20:18:52 +0000 (15:18 -0500)]
[dev.cc] 9a: make RET a synonym for RETURN; use "g" instead of "R30"
Previously, 9a was the only assembler that had a different
name for RET, causing unnecessary friction in simple files
that otherwise assembled on all architectures. Add RET so
these work on 9a.
This also renames "R30" to "g" to avoid unintentionally
clobbering g in assembly code. This parallels a change made
to 5a.
Russ Cox [Tue, 18 Nov 2014 17:07:50 +0000 (12:07 -0500)]
[dev.cc] runtime: generate GOOS- and GOARCH-specific files with go generate
Eventually I'd like almost everything cmd/dist generates
to be done with 'go generate' and checked in, to simplify
the bootstrap process. The only thing cmd/dist really needs
to do is write things like the current experiment info and
the current version.
This is a first step toward that. It replaces the _NaCl etc
constants with generated ones goos_nacl, goos_darwin,
goarch_386, and so on.
LGTM=dave, austin
R=austin, dave, bradfitz
CC=golang-codereviews, iant, r
https://golang.org/cl/174290043
David du Colombier [Sun, 16 Nov 2014 21:55:07 +0000 (22:55 +0100)]
[dev.cc] cmd/8g: work around "out of fixed registers" on Plan 9
This change works around the "out of fixed registers"
issue with the Plan 9 C compiler on 386, introduced by
the Bits change to uint64 in CL 169060043.
The purpose of this CL is to be able to properly
follow the conversion of the Plan 9 runtime to Go
on the Plan 9 builders.
This CL could be reverted once the Go compilers will
be converted to Go.
Thanks to Nick Owens for investigating this issue.
Dave Cheney [Sat, 15 Nov 2014 02:27:05 +0000 (13:27 +1100)]
[dev.cc] runtime: fix _sfloat thunk
* _sfloat dispatches to runtime._sfloat2 with the Go calling convention, so the seecond argument is a [15]uint32, not a *[15]uint32.
* adjust _sfloat2 to return the new pc in 68(R13) as expected.
David du Colombier [Fri, 14 Nov 2014 21:57:33 +0000 (22:57 +0100)]
[dev.cc] liblink: fix warnings on Plan 9
warning: src/liblink/asm9.c:501 set and not used: bflag
warning: src/liblink/list9.c:259 format mismatch .5lux INT, arg 4
warning: src/liblink/list9.c:261 format mismatch .5lux INT, arg 3
warning: src/liblink/list9.c:319 more arguments than format VLONG
warning: src/liblink/obj9.c:222 set and not used: autoffset
Austin Clements [Fri, 14 Nov 2014 18:58:31 +0000 (13:58 -0500)]
[dev.power64] 6g,9g: formatters for Prog and Addr details
The pretty printers for these make it hard to understand
what's actually in the fields of these structures. These
"ugly printers" show exactly what's in each field, which can
be useful for understanding and debugging code.
Austin Clements [Fri, 14 Nov 2014 17:08:46 +0000 (12:08 -0500)]
[dev.power64] liblink: generate dnames[5689] for D_* constants
This is more complicated than the other enums because the D_*
enums are full of explicit initializers and repeated values.
This tries its best. (This will get much cleaner once we
tease these constants apart better.)
Austin Clements [Fri, 14 Nov 2014 16:56:31 +0000 (11:56 -0500)]
[dev.power64] 5g,6g,8g,9g: debug prints for regopt pass 6 and paint2
Theses were very helpful in understanding the regions and
register selection when porting regopt to 9g. Add them to the
other compilers (and improve 9g's successor debug print).
Austin Clements [Thu, 13 Nov 2014 18:34:20 +0000 (13:34 -0500)]
[dev.power64] 6g,8g: remove unnecessary and incorrect reg use scanning
Previously, the 6g and 8g registerizers scanned for used
registers beyond the end of a region being considered for
registerization. This ancient artifact was copied from the C
compilers, where it was probably necessary to track implicitly
used registers. In the Go compilers it's harmless (because it
can only over-restrict the set of available registers), but no
longer necessary because the Go compilers correctly track
register use/set information. The consequences of this extra
scan were (at least) that 1) we would not consider allocating
the AX register if there was a deferproc call in the future
because deferproc uses AX as a return register, so we see the
use of AX, but don't track that AX is set by the CALL, and 2)
we could not consider allocating the DX register if there was
a MUL in the future because MUL implicitly sets DX and (thanks
to an abuse of copyu in this code) we would also consider DX
used.
This commit fixes these problems by nuking this code.
Russ Cox [Wed, 12 Nov 2014 19:54:31 +0000 (14:54 -0500)]
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack
Scalararg and ptrarg are not "signal safe".
Go code filling them out can be interrupted by a signal,
and then the signal handler runs, and if it also ends up
in Go code that uses scalararg or ptrarg, now the old
values have been smashed.
For the pieces of code that do need to run in a signal handler,
we introduced onM_signalok, which is really just onM
except that the _signalok is meant to convey that the caller
asserts that scalarg and ptrarg will be restored to their old
values after the call (instead of the usual behavior, zeroing them).
Scalararg and ptrarg are also untyped and therefore error-prone.
Go code can always pass a closure instead of using scalararg
and ptrarg; they were only really necessary for C code.
And there's no more C code.
For all these reasons, delete scalararg and ptrarg, converting
the few remaining references to use closures.
Once those are gone, there is no need for a distinction between
onM and onM_signalok, so replace both with a single function
equivalent to the current onM_signalok (that is, it can be called
on any of the curg, g0, and gsignal stacks).
The name onM and the phrase 'm stack' are misnomers,
because on most system an M has two system stacks:
the main thread stack and the signal handling stack.
Correct the misnomer by naming the replacement function systemstack.
Fix a few references to "M stack" in code.
The main motivation for this change is to eliminate scalararg/ptrarg.
Rick and I have already seen them cause problems because
the calling sequence m.ptrarg[0] = p is a heap pointer assignment,
so it gets a write barrier. The write barrier also uses onM, so it has
all the same problems as if it were being invoked by a signal handler.
We worked around this by saving and restoring the old values
and by calling onM_signalok, but there's no point in keeping this nice
home for bugs around any longer.
This CL also changes funcline to return the file name as a result
instead of filling in a passed-in *string. (The *string signature is
left over from when the code was written in and called from C.)
That's arguably an unrelated change, except that once I had done
the ptrarg/scalararg/onM cleanup I started getting false positives
about the *string argument escaping (not allowed in package runtime).
The compiler is wrong, but the easiest fix is to write the code like
Go code instead of like C code. I am a bit worried that the compiler
is wrong because of some use of uninitialized memory in the escape
analysis. If that's the reason, it will go away when we convert the
compiler to Go. (And if not, we'll debug it the next time.)
Russ Cox [Tue, 11 Nov 2014 22:05:55 +0000 (17:05 -0500)]
[dev.cc] runtime: convert signal handlers from C to Go
This code overused macros and could not be
converted automatically. Instead a new sigctxt
type had to be defined for each os/arch combination,
with a common (implicit) interface used by the
arch-specific signal handler code.
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
Russ Cox [Tue, 11 Nov 2014 06:29:05 +0000 (01:29 -0500)]
[dev.cc] cmd/dist: adjust for build process without cmd/cc
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
- Remove references to C compiler directories.
- Remove generation of special header files.
- Remove generation of Go source files from C declarations.
- Compile Go sources before rest of package (was after),
so that Go compiler can write go_asm.h for use in assembly.
- Move TLS information from cmd/dist (was embedding in output)
to src/runtime/go_tls.h, which it can be maintained directly.
LGTM=r
R=r, dave
CC=austin, golang-codereviews, iant, khr
https://golang.org/cl/172960043
Russ Cox [Tue, 11 Nov 2014 06:28:26 +0000 (01:28 -0500)]
[dev.cc] liblink: resolve bss vs other conflict regardless of order found
If the linker finds the same name given a BSS and a non-BSS
symbol, the assumption is that the non-BSS symbol is the
true one, and the BSS symbol is just the best Go can do toward
an "extern" declaration. This has always been the case,
as long as the object files were read in the right order.
The old code worked when the BSS symbol is found before
the non-BSS symbol. This CL adds equivalent logic for when
the non-BSS symbol is found before the BSS symbol.
This comes up when Go must refer to symbols defined in
host object files.
Russ Cox [Tue, 11 Nov 2014 06:27:55 +0000 (01:27 -0500)]
[dev.cc] cmd/go: adjust go, cgo builds & disable cc
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
Make gcToolchain.cc return an error (no C compiler!).
Adjust expectations of cgo, now that cgo does not write any C files
(no C compiler!).
For packages with .s files, invoke Go compiler with -asmhdr go_asm.h
so that assembly files can use it. This applies to all packages but is only
needed today by package runtime.
Russ Cox [Tue, 11 Nov 2014 06:27:30 +0000 (01:27 -0500)]
[dev.cc] cmd/gc: changes for removing runtime C code
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
export.c, lex.c:
Add -asmhdr flag to write assembly header file with struct
field offsets and const values. cmd/dist used to construct this
file by interpreting output from the C compiler.
Generate it from the Go definitions instead.
Also, generate the form we need directly, instead of relying
on cmd/dist for reprocessing.
lex.c, obj.c:
If the C compiler accepted #pragma cgo_xxx, recognize
a directive //go:cgo_xxx instead. The effect is the same as
in the C compiler: accumulate text into a buffer and emit in the
output file, where the linker will find and use it.
lex.c, obj.c:
Accept //go:linkname to control the external symbol name
used for a particular top-level Go variable. This makes it
possible to refer to C symbol names but also symbols from
other packages. It has always been possible to do this from
C and assembly. To drive home the point that this should not
be done lightly, require import "unsafe" in any file containing
//go:linkname.
plive.c, reflect.c, subr.c:
Hard-code that interfaces contain only pointers.
This means code handling multiword values in the garbage
collector and the stack copier can be deleted instead of being
converted. This change is already present in the dev.garbage
branch.
Russ Cox [Tue, 11 Nov 2014 06:23:19 +0000 (01:23 -0500)]
[dev.cc] cmd/cgo: generate only Go source files
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
We changed cgo to write the actual function wrappers in Go
for Go 1.4. The only code left in C output files was the definitions
for pointers to C data and the #pragma cgo directives.
Write both of those to Go outputs instead, using the new
compiler directives introduced in CL 169360043.
Russ Cox [Mon, 10 Nov 2014 02:14:36 +0000 (21:14 -0500)]
[dev.cc] create new branch
This branch is for work on converting the remaining C code in
package runtime to Go and then deleting the cc, 5c, 6c, and 8c
directories. It is targeted to land at the beginning of the 1.5 cycle.
The conversion will proceed one GOOS/GOARCH combination
at a time; red lines on the dashboard are expected and okay.
Once Linux and OS X are converted, help with other systems
will be most welcome.
Adam Langley [Sun, 9 Nov 2014 01:12:23 +0000 (17:12 -0800)]
lib/codereview: fix with more recent hg revisions.
I've Mercurial version 3.2 and hg submit fails with:
File "/home/agl/devel/go/lib/codereview/codereview.py", line 3567, in get_hg_status
ret = hg_commands.status(fui, self.repo, *[], **{'rev': [rev], 'copies': True})
File "/usr/lib/python2.7/site-packages/mercurial/commands.py", line 5714, in status
fm = ui.formatter('status', opts)
File "/home/agl/devel/go/lib/codereview/codereview.py", line 3464, in formatter
return plainformatter(self, topic, opts)
File "/usr/lib/python2.7/site-packages/mercurial/formatter.py", line 57, in __init__
if ui.debugflag:
AttributeError: 'FakeMercurialUI' object has no attribute 'debugflag'
This change dumbly adds a boolean debugflag and that seems to work.
Austin Clements [Fri, 7 Nov 2014 15:43:55 +0000 (10:43 -0500)]
[dev.power64] 5g: fix mistaken bit-wise AND in regopt
Replace a bit-wise AND with a logical one. This happened to
work before because bany returns 0 or 1, but the intent here
is clearly logical (and this makes 5g match with 6g and 8g).
Russ Cox [Fri, 7 Nov 2014 00:56:55 +0000 (19:56 -0500)]
cmd/objdump, cmd/pprof: factor disassembly into cmd/internal/objfile
Moving so that new Go 1.4 pprof can use it.
The old 'GNU objdump workalike' mode for 'go tool objdump'
is now gone, as are the tests for that mode. It was used only
by pre-Go 1.4 pprof. You can still specify an address range on
the command line; you just get the same output format as
you do when dumping the entire binary (without an address
limitation).