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Commit Graph

562 Commits

Author SHA1 Message Date
David Crawshaw
dd0a128a02 cmd/link: make rddataBufMax a const
Change-Id: I1ece7463d35efba0e8d2b1e61727dd25283ff720
Reviewed-on: https://go-review.googlesource.com/20059
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-01 18:08:02 +00:00
Shahar Kohanim
d3b00a8cc4 cmd/link: batch writing of bytes
In best of 10, linking cmd/go shows a ~10% improvement.

tip:              real  0m1.152s user  0m1.005s
this:             real  0m1.065s user  0m0.924s

Change-Id: I303a20b94332feaedc1033c453247a0e4c05c843
Reviewed-on: https://go-review.googlesource.com/19978
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-02-29 23:54:19 +00:00
David Crawshaw
07ccc21295 cmd/link: skip allocation when reading symbol name
The object file reader in cmd/link reads the symbol name into a scratch
[]byte, converts it to a string, and then does a substring replacement.
Instead, this CL does the replacement on the []byte into the scratch
space and then creates the final string.

Linking godoc without DWARF, best of ten, shows a ~10% improvement.

tip:           real 0m1.099s user 0m1.541s
this:          real 0m0.990s user 0m1.280s

This is part of an attempt to make suffixarray string deduping
come out as a wash, but it's not there yet:

cl/19987:      real 0m1.335s user 0m1.794s
cl/19987+this: real 0m1.225s user 0m1.540s

Change-Id: Idf061fdfbd7f08aa3a1f5933d3f111fdd1659210
Reviewed-on: https://go-review.googlesource.com/20025
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-29 19:30:48 +00:00
David Crawshaw
6d0b551931 cmd/link: track offset instead of using seek
The Cpos function is used frequently (at least once per symbol) and
it is implemented with the seek syscall. Instead, track current
output offset and use it.

Building the godoc binary with DWARF, best of ten:

tip:  real 0m1.287s user 0m1.573s
this: real 0m1.208s user 0m1.555s

Change-Id: I068148695cd6b4d32cd145db25e59e6f6bae6945
Reviewed-on: https://go-review.googlesource.com/20055
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-29 19:14:20 +00:00
David Crawshaw
36f25a7e7b cmd/link: allocate small []byte reads together
Reduces number of memory allocations by 12%:

Before: 1816664
After:  1581591

Small speed improvement.

Change-Id: I61281fb852e8e31851a350e3ae756676705024a4
Reviewed-on: https://go-review.googlesource.com/20027
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-29 18:45:35 +00:00
Shahar Kohanim
8096881927 cmd/link: batch allocations of Lsym
Reduces best of 10 linking of cmd/go by ~5%

Change-Id: If673b877ee12595dae517d7eb48430451e5cadba
Reviewed-on: https://go-review.googlesource.com/20060
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-29 17:32:11 +00:00
Shahar Kohanim
e0b04fa508 cmd/link: Preallocate Lsym map
Preallocate ~2MB for Lsym map (size calculation from http://play.golang.org/p/9L7F5naXRr).
Reduces best of 10 link time of cmd/go by ~4%.
On cmd/go max resident size unaffected, on println hello world max resident size grows by 4mb from 18mb->22mb. Performance improves in both cases.

tip:  real  0m1.283s user  0m1.502s sys 0m0.144s
this: real  0m1.341s user  0m1.598s sys 0m0.136s

Change-Id: I4a95e45fe552f1f64f53e868421b9f45a34f8b96
Reviewed-on: https://go-review.googlesource.com/19979
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-02-29 17:30:13 +00:00
Matthew Dempsky
67dbde0d71 cmd: stop looking for __.(GO)?SYMDEF entries in archives
The Go toolchain stopped creating them before Go 1.3, so no point in
worrying about them today.

History:

- Git commit 250a091 added cmd/ar, which wrote Plan 9 __.SYMDEF
entries into archive files.

- golang.org/cl/6500117 renamed __.SYMDEF to __.GOSYMDEF.  (Notably,
the commit message suggests users need to use Go nm to read symbols,
but even back then the toolchain did nothing with __.(GO)?SYMDEF files
except skip over them.)

- golang.org/cl/42880043 added the -pack flag to cmd/gc to directly
produce archives by the Go compiler, and did not write __.GOSYMDEF
entries.

- golang.org/cl/52310044 rewrote cmd/pack in Go, and removed support
for producing __.GOSYMDEF entries.

Change-Id: I255edf40d0d3690e3447e488039fcdef73c6d6b1
Reviewed-on: https://go-review.googlesource.com/19924
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-26 20:26:17 +00:00
David Crawshaw
30f93f0994 cmd/compile: remove rtype.ptrToThis
Simplifies some code as ptrToThis was unreliable under dynamic
linking. Now the same type lookup is used regardless of execution
mode.

A synthetic relocation, R_USETYPE, is introduced to make sure the
linker includes *T on use of T, if *T is carrying methods.

Changes the heap dump format. Anything reading the format needs to
look at the last bool of a type of an interface value to determine
if the type should be the pointer-to type.

Reduces binary size of cmd/go by 0.2%.
For #6853.

Change-Id: I79fcb19a97402bdb0193f3c7f6d94ddf061ee7b2
Reviewed-on: https://go-review.googlesource.com/19695
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-25 17:47:42 +00:00
Martin Möhrmann
fdd0179bb1 all: fix typos and spelling
Change-Id: Icd06d99c42b8299fd931c7da821e1f418684d913
Reviewed-on: https://go-review.googlesource.com/19829
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-24 18:42:29 +00:00
David Crawshaw
a858931200 cmd/compile: embed type string header in rtype
Reduces binary size of cmd/go by 1%.

For #6853.

Change-Id: I6f2992a4dd3699db1b532ab08683e82741b9c2e4
Reviewed-on: https://go-review.googlesource.com/19692
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-24 17:12:15 +00:00
David Crawshaw
41eb5ca089 cmd/link: typo in error message
Change-Id: Ideeef320d6a01a10c89524b6d895a64210a60f64
Reviewed-on: https://go-review.googlesource.com/19693
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-20 20:16:17 +00:00
Russ Cox
51b624e6a2 cmd/link: remove alternate -X flag spelling
The Go 1.6 release notes say we'll remove the “-X name value” form
(in favor of the “-X name=value” form) in Go 1.7.
Do that.

Also establish the doc/go1.7.txt file.

Change-Id: Ie4565a6bc5dbcf155181754d8d92bfbb23c75338
Reviewed-on: https://go-review.googlesource.com/19614
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-02-19 01:35:25 +00:00
Rhys Hiltner
98cc8b4cf2 cmd/link/internal/ld: remove unused call to os.Getwd
This call to os.Getwd (or getwd) has been part of the linker since the C
implementation in 7d507dc6e6. It stopped being used in 26438d4d80, and
survived the conversion to Go in 1f9dbb60ef.

Its return value goes unused (the linker gets the value for AT_comp_dir in
dwarf.go), remove it.

Change-Id: I3d4594813bb4ee0a6af31a36e19d99ec4b863677
Reviewed-on: https://go-review.googlesource.com/19655
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-18 22:34:29 +00:00
Damien Neil
5bbb98df09 cmd/go, cmd/link: make builds deterministic
Add the following flags when supported by the compiler:
  -gno-record-gcc-switches
  -fdebug-prefix-map=$WORK=/tmp/go-build

Add an empty NAME symbol to the ELF .symtab. GNU ld will add a NAME
symbol when one is not present; including one of our own prevents it
from adding a reference to the link tempdir.

Fixes #13247 for compilers that support -fdebug-prefix-map. (gcc, clang
in the near future.)

Change-Id: I221c71fc59cd23ee8c99bcc038793ff4623c9ffc
Reviewed-on: https://go-review.googlesource.com/19363
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>
2016-02-18 20:56:29 +00:00
Ryan Brown
68aa7fb636 cmd/link: fix padding for dwarf aranges on 32 bit platforms.
Fixes #14278

Change-Id: I6a0c1370d595f0573ff0eb933450b1eea41f4bb3
Reviewed-on: https://go-review.googlesource.com/19452
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-02-12 19:13:11 +00:00
Richard Miller
bd7e084d7d cmd/link: correct byte ordering in plan9_arm object header
Fields in Plan 9 object headers are big-endian, on all architectures.

Change-Id: If95ad29750b776338178d660646568bf26a4abda
Reviewed-on: https://go-review.googlesource.com/18964
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-27 15:52:44 +00:00
Ian Lance Taylor
1aab7b9626 cmd/link: add -extar option to set ar program for c-archive
People who want to use -buildmode=c-archive in unusual cross-compilation
setups will need something like this.  It could also be done via (yet
another) environment variable but I use -extar by analogy with the
existing -extld.

Change-Id: I354cfabc4c470603affd13cd946997b3a24c0e6c
Reviewed-on: https://go-review.googlesource.com/18913
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-01-26 18:52:36 +00:00
Michael Hudson-Doyle
cd9fc3ebfb cmd/link: allow symbols from .a files to override those from .so files
https://golang.org/s/execmodes defines rules for how multiple codes of a go
package work when they end up in the address space of a single process, but
currently the linker blows up in this situation. Fix that by loading all .a
files before any .so files and ignoring duplicate symbols found when loading
shared libraries.

I know this is very very late for 1.6 but at least it should clearly not have
any effect when shared libraries are not in use.

Change-Id: I512ac912937e7502ff58eb5628b658ecce3c38e5
Reviewed-on: https://go-review.googlesource.com/18714
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2016-01-20 19:53:53 +00:00
OneOfOne
5e7110b92b cmd/link: fix elf64phdr to allow using upx (and other broken ELF loaders).
The linker already applies the fix for elf32, so this just extends it to elf64.

Inspired by https://github.com/pwaller/goupx

Fixes #13974

Change-Id: I65d92b5be9590657060a0e8e80ff5b86ba40017f
Reviewed-on: https://go-review.googlesource.com/18690
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-01-19 18:01:33 +00:00
Russ Cox
4a0eee2faa cmd/link: add LC_VERSION_MIN_MACOSX to linkmode=internal OS X binaries
This makes lldb willing to debug them.
The minimum version is hard-coded at OS X 10.7,
because that is the minimum that Go requires.
For more control over the version, users can
use linkmode=external and pass the relevant flags to the host linker.

Fixes #12941.

Change-Id: I20027be8aa034d07dd2a3326828f75170afe905f
Reviewed-on: https://go-review.googlesource.com/18588
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-01-13 19:06:40 +00:00
Joe Sylve
9efc46f1cb cmd/go: -buildmode=c-shared should work on darwin/386
* Enable c-shared buildmode on darwin/386
* dyld does not support text relocation on i386. Add -read_only_relocs suppress flag to linker

Fixes #13904

Change-Id: I9adbd20d3f36ce9bbccf1bffb746b391780d088f
Reviewed-on: https://go-review.googlesource.com/18500
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-13 18:24:38 +00:00
Austin Clements
fdf9b3c994 runtime: increase assumed stack size in externalthreadhandler
On Windows, externalthreadhandler currently sets the assumed stack
size for the profiler thread and the ctrlhandler threads to 8KB. The
actual stack size is determined by the SizeOfStackReserve field in the
binary set by the linker, which is currently at least 64KB (and
typically 128KB).

It turns out the profiler thread is running within a few words of the
8KB-(stack guard) bound set by externalthreadhandler. If it overflows
this bound, morestack crashes unceremoniously with an access
violation, which we then fail to handle, causing the whole process to
exit without explanation.

To avoid this problem and give us some breathing room, increase the
assumed stack size in externalthreadhandler to 32KB (there's some
unknown amount of stack already in use, so it's not safe to increase
this all the way to the reserve size).

We also document the relationships between externalthreadhandler and
SizeOfStackReserve to make this more obvious in the future.

Change-Id: I2f9f9c0892076d78e09827022ff0f2bedd9680a9
Reviewed-on: https://go-review.googlesource.com/18304
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Minux Ma <minux@golang.org>
2016-01-07 19:40:32 +00:00
Russ Cox
83746fd55a cmd/link: use current GOROOT for source file paths for standard library
This CL changes the source file information in the
standard library's .a files to say "$GOROOT/src/runtime/chan.go"
(with a literal "$GOROOT") instead of spelling out the actual directory.
The linker then substitutes the actual $GOROOT (or $GOROOT_FINAL)
as appropriate.

If people download a binary distribution to an alternate location,
following the instructions at https://golang.org/doc/install#install,
the code before this CL would end up with source paths pointing to
/usr/local/go no matter where the actual sources were.
Now the source paths for built binaries will point to the actual sources
(hopefully).

The source line information in distributed binaries is not affected:
those will still say /usr/local/go. But binaries people build themselves
(their own programs, not the go distribution programs) will be correct.

Fixing this path also fixes the lookup of the runtime-gdb.py file.

Fixes #5533.

Change-Id: I03729baae3fbd8cd636e016275ee5ad2606e4663
Reviewed-on: https://go-review.googlesource.com/18200
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-01-04 20:09:57 +00:00
Russ Cox
c7b1ef9918 cmd/link: reject non-package main toplevel.a file, remove dead code
The test for non-package main top-level inputs is done while parsing
the export data. Issue #13468 happened because we were not parsing
the export data when using compiler-generated archives
(that is, when using go tool compile -pack).

Fix this by parsing the export data even for archives.

However, that turns up a different problem: the export data check
reports (one assumes spurious) skew errors now, because it has
not been run since Go 1.2.
(Go 1.3 was the first release to use go tool compile -pack.)

Since the code hasn't run since Go 1.2, it can't be that important.
Since it doesn't work today, just delete it.

Figuring out how to make this code work with Robert's export
format was one of the largest remaining TODOs for that format.
Now we don't have to.

Fixes #13468 and makes the world a better place.

Change-Id: I40a4b284cf140d49d48b714bd80762d6889acdb9
Reviewed-on: https://go-review.googlesource.com/17976
Reviewed-by: Robert Griesemer <gri@golang.org>
2015-12-17 20:59:51 +00:00
Didier Spezia
77328b8d12 cmd/link: clean up dwarf.go
Try to remove the most visible artefacts resulting from the
C to Go translation. It includes:

- refactoring the find function to eliminate goto and variable declarations
- removing useless variables still having a _ = xxx
- decreasing the number of upfront variable declarations

No semantic changes.

Change-Id: I84d981c48b2d9e22e6b9db5f2a703c80c60249ba
Reviewed-on: https://go-review.googlesource.com/15681
Reviewed-by: Russ Cox <rsc@golang.org>
2015-12-05 04:13:18 +00:00
Ian Lance Taylor
f1b919574c cmd/link: support R_PPC_REL32 relocation
This relocation is found in libgcc.a in the .eh_frame, and therefore
needs to be handled when doing an internal link.

Fixes #13375.

Change-Id: Idd9e8178e08851a101b43261a30939bcfaf394f9
Reviewed-on: https://go-review.googlesource.com/17173
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2015-11-24 00:02:06 +00:00
Hyang-Ah Hana Kim
bda885511d cmd: allow buildmode=c-shared for android/386
Update golang/go#9327.

Change-Id: Iab7dad31cf6b9f9347c3f34faebb67ecb38b17fc
Reviewed-on: https://go-review.googlesource.com/16701
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-20 14:55:35 +00:00
Hyang-Ah Hana Kim
cbc55971e2 cmd/go, cmd/link: enable -buildmode=c-shared on linux/386
All the heavy lifting was done by Michael Hudson-Doyle.

Change-Id: I176f15581055078854c2ad9a5807c4dcf0f8d8c5
Reviewed-on: https://go-review.googlesource.com/17074
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-11-20 03:49:13 +00:00
Michael Hudson-Doyle
09d7de8d61 cmd/link, runtime: call addmoduledata when dynamically linking on linux/386
Change-Id: If1faa2bba28a4e9a8061693173797c4114a7d699
Reviewed-on: https://go-review.googlesource.com/16387
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-19 00:22:56 +00:00
Michael Hudson-Doyle
342f17eaf7 cmd/internal/obj/x86, cmd/link: enable access to global data via GOT when -dynlink on 386
Change-Id: I97504a11291ee60e656efb7704e37387e864d74f
Reviewed-on: https://go-review.googlesource.com/16385
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-18 21:27:45 +00:00
Russ Cox
6bf794a36d cmd/link: link go.o first
Does not fix #12327 but nicer anyway.

Change-Id: I4ad730a4ca833d76957b7571895b3a08a6a530d4
Reviewed-on: https://go-review.googlesource.com/16964
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-18 19:00:45 +00:00
Ian Lance Taylor
8d2f60f8a8 cmd/link: add -libgcc option
An internal link may need the C compiler support library, libgcc.a.  Add
a -libgcc option to set the name of the compiler support library.  If
-libgcc is not used, run the compiler to find it.  Permit -libgcc=none
to skip using libgcc at all and hope for the best.

Change cmd/dist to not copy libgcc into the distribution.  Add tests to
ensure that all the standard packages that use cgo can be linked in
internal mode without using libgcc.  This ensures that somebody with a
Go installation without a C compiler can build programs.

Change-Id: I8ba35fb87ab0dd20e5cc0166b5f4145b04ce52a4
Reviewed-on: https://go-review.googlesource.com/16993
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-11-18 02:04:10 +00:00
Michael Hudson-Doyle
3bf61fb2e5 cmd/internal/obj/x86, cmd/link/internal/x86: support IE model TLS on linux/386
This includes the first parts of the general approach to PIC: load PC into CX
whenever it is needed. This is going to lead to large binaries and poor
performance but it's a start and easy to get right.

Change-Id: Ic8bf1d0a74284cca0d94a68cf75024e8ab063b4e
Reviewed-on: https://go-review.googlesource.com/16383
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-18 01:57:01 +00:00
Michael Hudson-Doyle
4bae454d68 cmd/link: work around arm64 linker bugs with GOT relocations against local symbols
Change-Id: Ie14530c57720f1af1960ab77686b860e906058c6
Reviewed-on: https://go-review.googlesource.com/16582
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-15 23:40:59 +00:00
Michael Hudson-Doyle
3534e2bef4 cmd/internal/obj, cmd/link: access global data via a GOT in -dynlink mode on arm64
Change-Id: I6ca9406207e40c7c2c661075ccfe57b6600235cf
Reviewed-on: https://go-review.googlesource.com/13997
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-15 23:40:22 +00:00
Ian Lance Taylor
754f707f5f cmd/link, cmd/go, cmd/dist: use copy of libgcc.a for internal linking
Change the linker to use a copy of the C compiler support library,
libgcc.a, when doing internal linking.  This will be used to satisfy any
undefined symbols referenced by host objects.

Change the dist tool to copy the support library into a new directory
tree under GOROOT/pkg/libgcc.  This ensures that libgcc is available
even when building Go programs on a system that has no C compiler.  The
C compiler is required when building the Go installation in the first
place, but is not required thereafter.

Change the go tool to not link libgcc into cgo objects.

Correct the linker handling of a weak symbol in an ELF input object to
not always create a new symbol, but to use an existing symbol if there
is one; this is necessary on freebsd-amd64, where libgcc contains a weak
definition of compilerrt_abort_impl.

Fixes #9510.

Change-Id: I1ab28182263238d9bcaf6a42804e5da2a87d8778
Reviewed-on: https://go-review.googlesource.com/16741
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-14 18:56:17 +00:00
David Crawshaw
9958a7b563 Revert "cmd/internal/obj/arm64, cmd/link: use two instructions rather than three for loads from memory"
This reverts commit 3a9bc571b0.

Breaks darwin/arm64.

Change-Id: Ib958beacabca48020a6a47332fbdec99d994060b
Reviewed-on: https://go-review.googlesource.com/16906
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2015-11-13 11:40:10 +00:00
Michael Hudson-Doyle
1ccefcd1b8 cmd/link, runtime: implement & call addmoduledata on ppc64le
Change-Id: I3980d82c7df95e69522c3d2c90311f89c6fef0e1
Reviewed-on: https://go-review.googlesource.com/15972
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-13 00:51:45 +00:00
Michael Hudson-Doyle
2ac993107f cmd/internal/obj, cmd/link: access global data via GOT when dynlinking on ppc64le
Change-Id: I79c60241df6c785f35371e70c777a7bd6e93571c
Reviewed-on: https://go-review.googlesource.com/15968
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-13 00:25:21 +00:00
Michael Hudson-Doyle
9a476028c0 cmd/go, cmd/link: enable -buildmode=shared on linux/ppc64le
Change-Id: Ifba76413b8aa78a221385bf505b92a3a5fbc3d24
Reviewed-on: https://go-review.googlesource.com/16713
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-11-12 23:58:52 +00:00
Michael Hudson-Doyle
a35c85c0cc cmd/internal/obj, runtime: implement IE model TLS on ppc64le
This requires changing the tls access code to match the patterns documented in
the ABI documentation or the system linker will "optimize" it into ridiculousness.

With this change, -buildmode=pie works, although as it is tested in testshared,
the tests are not run yet.

Change-Id: I1efa6687af0a5b8db3385b10f6542a49056b2eb3
Reviewed-on: https://go-review.googlesource.com/15971
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-12 23:50:27 +00:00
Michael Hudson-Doyle
bd329d47d9 cmd/internal/obj, cmd/link: generate position independent loads of static data
Change-Id: I0a8448c2b69f5cfa6f099d772f5eb3412f853045
Reviewed-on: https://go-review.googlesource.com/15969
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-12 23:33:12 +00:00
Michael Hudson-Doyle
368d548417 cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC
The PowerPC ISA does not have a PC-relative load instruction, which poses
obvious challenges when generating position-independent code. The way the ELFv2
ABI addresses this is to specify that r2 points to a per "module" (shared
library or executable) TOC pointer. Maintaining this pointer requires
cooperation between codegen and the system linker:

 * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer.
 * A call to a function that *might* have to go via a PLT stub must be followed
   by a nop instruction that the system linker can replace with "ld r1, 24(r1)"
   to restore the TOC pointer (only when dynamically linking Go code).
 * When calling a function via a function pointer, the address of the function
   must be in r12, and the first couple of instructions (the "global entry
   point") of the called function use this to derive the address of the TOC
   for the module it is in.
 * When calling a function that is implemented in the same module, the system
   linker adjusts the call to skip over the instructions mentioned above (the
   "local entry point"), assuming that r2 is already correctly set.

So this changeset adds the global entry point instructions, sets the metadata so
the system linker knows where the local entry point is, inserts code to save the
TOC pointer at 24(r1), adds a nop after any call not known to be local and copes
with the odd non-local code transfer in the runtime (e.g. the stuff around
jmpdefer). It does not actually compile PIC yet.

Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854
Reviewed-on: https://go-review.googlesource.com/15967
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-12 23:18:58 +00:00
Michael Hudson-Doyle
c83c806535 cmd/internal/obj, cmd/link, runtime: use a larger stack frame on ppc64
The larger stack frames causes the nosplit stack to overflow so the next change
increases the stackguard.

Change-Id: Ib2b4f24f0649eb1d13e3a58d265f13d1b6cc9bf9
Reviewed-on: https://go-review.googlesource.com/15964
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-12 22:32:37 +00:00
Yao Zhang
053c75411f cmd/link: added support for mips64{,le}
Only internal linking without cgo is supported for now.

Change-Id: Ie6074a8ff3ec13605b72028f2d60758034f87185
Reviewed-on: https://go-review.googlesource.com/14444
Reviewed-by: Minux Ma <minux@golang.org>
2015-11-12 04:44:00 +00:00
Michael Hudson-Doyle
cf125a36d5 cmd/link: fix size of filetab slice
The linker writes the number of file symbols (Nhistfile) to the filetab slice
and then Nhistfile offsets -- which means the slice contains Nhistfile+1
entries, not just Nhistfile.

I think this bug has been around since at least 1.4 but it's easier to trigger
with shared libraries and a tiny binary that only has a couple of functions in
it -- try go install -buildmode=shared std && go run -linkshared test/fixedbugs/issue4388.go.

Change-Id: I6c0f01f1e607b9b2b96872e37ffce81281911504
Reviewed-on: https://go-review.googlesource.com/16342
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-11 23:17:25 +00:00
Hyang-Ah Hana Kim
05c4c6e2f4 cmd,runtime: TLS setup for android/386
Same ugly hack as https://go-review.googlesource.com/15991.

Update golang/go#9327.

Change-Id: I58284e83268a15de95eabc833c3e01bf1e3faa2e
Reviewed-on: https://go-review.googlesource.com/16678
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-11 21:59:24 +00:00
Michael Hudson-Doyle
c155e59062 cmd/link: enable external linking on ppc64
Change-Id: Iffe8ccb55b2c555b2cb8c168cebfbfd5892212df
Reviewed-on: https://go-review.googlesource.com/14236
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-10 01:47:41 +00:00
Michael Hudson-Doyle
4e3deae96d cmd/link, runtime: arm64 implementation of addmoduledata
Change-Id: I62fb5b20d7caa51b77560a4bfb74a39f17089805
Reviewed-on: https://go-review.googlesource.com/13999
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-10 01:24:25 +00:00
Michael Hudson-Doyle
712ffc0861 cmd/link: look at the R_AARCH64_RELATIVE relocs to find the gcdata on arm64
Change-Id: I5a1864a27ad917aa65c8e65a133f6cc0a980d05f
Reviewed-on: https://go-review.googlesource.com/13998
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-09 22:52:48 +00:00
Michael Hudson-Doyle
3a9bc571b0 cmd/internal/obj/arm64, cmd/link: use two instructions rather than three for loads from memory
Reduces size of godoc .text section by about 75k (or 1.4%).

Change-Id: I65850aa569aefbddd6cb07c6ae1addcc39cab6a5
Reviewed-on: https://go-review.googlesource.com/13993
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-09 22:03:11 +00:00
Michael Hudson-Doyle
1b4d28f8cf cmd/link, runtime: arm implementation of addmoduledata
Change-Id: I3975e10c2445e23c2798a7203a877ff2de3427c7
Reviewed-on: https://go-review.googlesource.com/14189
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-08 21:46:17 +00:00
Michael Hudson-Doyle
2ffdbd7ce4 cmd/go, cmd/link: allow -buildmode=pie on linux/ppc64le
Change-Id: I0d0abbb9503c3a3c35d846fc0379836b2c483dea
Reviewed-on: https://go-review.googlesource.com/15962
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-11-08 20:31:26 +00:00
Michael Hudson-Doyle
5e1d0fcbed cmd/internal/obj, cmd/link: handle the fact that a few store/loads on ppc64 are DS form
Change-Id: I4fe1af48ec1cd8a23e2f7f2a0257dc989ff7aced
Reviewed-on: https://go-review.googlesource.com/14235
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-08 19:35:47 +00:00
Tamir Duberstein
bb20266c9d cmd/internal/ld: skip dwarf output if dsymutil no-ops
Fixes #11994.

Change-Id: Icee6ffa6e3a9d15b68b4ae9b2716d65ecbdba73a
Reviewed-on: https://go-review.googlesource.com/16702
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-08 19:33:35 +00:00
Ian Lance Taylor
26263354a3 cmd/link: don't warn about unnamed symbols in .debug_str section
They reportedly occur with LLVM 3.7 on FreeBSD ARM.

Fixes #13139.

Change-Id: Ia7d053a8662696b1984e81fbd1d908c951c35a98
Reviewed-on: https://go-review.googlesource.com/16667
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-11-06 05:23:30 +00:00
Michael Hudson-Doyle
ebafc80eba cmd/link: remove duplicate symtab entry for global functions
golang.org/cl/16436 added a local symbol for every global function, but also
added a duplicate entry for the global symbol. Surprisingly this hasn't caused
any noticeable problems, but it's still wrong.

Change-Id: Icd3906760f8aaf7bef31ffd4f2d866d73d36dc2c
Reviewed-on: https://go-review.googlesource.com/16581
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-02 23:07:12 +00:00
David Crawshaw
cf73357e37 cmd/link: concurrent obj copy for external linking
Change-Id: I630ae29ecb39252642883398cc51d49133c6f3d7
Reviewed-on: https://go-review.googlesource.com/16451
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-11-02 17:52:55 +00:00
Ian Lance Taylor
914db9f060 cmd/link: support new 386/amd64 relocations
The GNU binutils recently picked up support for new 386/amd64
relocations.  Add support for them in the Go linker when doing an
internal link.

The 386 relocation R_386_GOT32X was proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I .  It can
be treated as identical to the R_386_GOT32 relocation.

The amd64 relocations R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were
proposed in
https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0 .  They
can both be treated as identical to the R_X86_64_GOTPCREL relocation.

The purpose of the new relocations is to permit additional linker
relaxations in some cases.  We do not attempt to support those cases.

While we're at it, remove the unused and in some cases out of date
_COUNT names from ld/elf.go.

Fixes #13114.

Change-Id: I34ef07f6fcd00cdd2996038ecf46bb77a49e968b
Reviewed-on: https://go-review.googlesource.com/16529
Reviewed-by: Minux Ma <minux@golang.org>
2015-10-31 23:22:58 +00:00
Quentin Perez
70119accdf cmd/link/internal/ld: fix extra arguments Errorf
lib.go:1309
lib.go:1313
lib.go:1317
lib.go:1325

Change-Id: Ic3d3282d836c28f8bdeb5ce52fb7c018450871b9
Reviewed-on: https://go-review.googlesource.com/16473
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-30 17:23:13 +00:00
Michael Hudson-Doyle
c9b8cab16c cmd/internal/obj, cmd/link, runtime: handle TLS more like a platform linker on ppc64
On ppc64x, the thread pointer, held in R13, points 0x7000 bytes past where
thread-local storage begins (presumably to maximize the amount of storage that
can be accessed with a 16-bit signed displacement). The relocations used to
indicate thread-local storage to the platform linker account for this, so to be
able to support external linking we need to change things so the linker applies
this offset instead of the runtime assembly.

Change-Id: I2556c249ab2d802cae62c44b2b4c5b44787d7059
Reviewed-on: https://go-review.googlesource.com/14233
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2015-10-29 22:24:29 +00:00
Michael Hudson-Doyle
d821ae2a9e cmd/internal/obj, cmd/link: simplify ppc64 archreloc now that the original value is passed to it
And get rid of the stupid game of encoding the instruction in the addend.

Change-Id: Ib4de7515196cbc1e63b4261b01931cf02a44c1e6
Reviewed-on: https://go-review.googlesource.com/14055
Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-29 20:46:23 +00:00
Michael Hudson-Doyle
51586aadfb cmd/compile, cmd/go, cmd/link: enable -buildmode=shared and related flags on linux/arm64
Change-Id: Ibddbbf6f4a5bd336a8b234d40fad0fcea574cd6e
Reviewed-on: https://go-review.googlesource.com/13994
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-29 19:27:47 +00:00
Michael Hudson-Doyle
c34fb3cfc6 cmd/link: always resolve functions locally when linking dynamically
When dynamically linking, we want references to functions defined
in this module to always be to the function object, not to the
PLT. We force this by writing an additional local symbol for
every global function symbol and making all relocations against
the global symbol refer to this local symbol instead. This is
approximately equivalent to the ELF linker -Bsymbolic-functions
option, but that is buggy on several platforms.

Change-Id: Ie6983eb4d1947f8543736fd349f9a90df3cce91a
Reviewed-on: https://go-review.googlesource.com/16436
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-29 19:19:07 +00:00
David Crawshaw
ab7e82ef3b cmd/go: buildmode=c-shared support for linux/arm64
Change-Id: Ic826dc25b5203b2e9fc253d6fe997e4b41de3789
Reviewed-on: https://go-review.googlesource.com/16453
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-29 16:25:37 +00:00
Hyang-Ah Hana Kim
dfc8649854 runtime, cmd: TLS setup for android/amd64.
Android linker does not handle TLS for us. We set up the TLS slot
for g, as darwin/386,amd64 handle instead. This is disgusting and
fragile. We will eventually fix this ugly hack by taking advantage
of the recent TLS IE model implementation. (Instead of referencing
an GOT entry, make the code sequence look into the TLS variable that
holds the offset.)

The TLS slot for g in android/amd64 assumes a fixed offset from %fs.
See runtime/cgo/gcc_android_amd64.c for details.

For golang/go#10743

Change-Id: I1a3fc207946c665515f79026a56ea19134ede2dd
Reviewed-on: https://go-review.googlesource.com/15991
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-10-28 20:54:28 +00:00
Michael Hudson-Doyle
80d9106487 cmd/internal/obj, cmd/link: support inital-exec TLS on arm64
Change-Id: Iaf9159a68fa395245bc20ccb4a2a377f89371a7e
Reviewed-on: https://go-review.googlesource.com/13996
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-10-28 19:51:28 +00:00
Michael Hudson-Doyle
72180c3b82 cmd/internal/obj, cmd/link, runtime: native-ish support for tls on arm64
Fixes #10560

Change-Id: Iedffd9c236c4fbb386c3afc52c5a1457f96ef122
Reviewed-on: https://go-review.googlesource.com/13991
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-10-28 19:51:05 +00:00
Michael Hudson-Doyle
6736cb0df1 cmd/link: remove unused field LSym.Hash
Change-Id: Idc5c4a69919a8ed9d76d4a9cfd9827fb5c59dd11
Reviewed-on: https://go-review.googlesource.com/16389
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-28 04:28:38 +00:00
Michael Hudson-Doyle
3ae4dc8a75 cmd/compile, cmd/go, cmd/link: enable -buildmode=shared and related flags on linux/386
Change-Id: If3417135ca474468a480b08cf46334fda28f79b4
Reviewed-on: https://go-review.googlesource.com/16345
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-28 01:21:54 +00:00
David Crawshaw
b7e4de4b1e cmd/go, cmd/link: -buildmode=pie for linux/amd64
Depends on external linking right now. I have no immediate use for
this, but wanted to check how hard it is to support as android/amd64
is coming and it will require PIE.

Change-Id: I65c6b19159f40db4c79cf312cd0368c2b2527bfd
Reviewed-on: https://go-review.googlesource.com/16072
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-23 19:51:55 +00:00
Robert Griesemer
28ef4c38c8 cmd/link/internal/ld: export data may be marked with $$ or $$B
Preparation for dealing with binary export format. Accept $$B
as marker for export data. For now, skip that data if found.

Change-Id: I464ba22aaedcf349725379d91070fc900d93b7a2
Reviewed-on: https://go-review.googlesource.com/16222
Reviewed-by: Chris Manghane <cmang@golang.org>
2015-10-22 18:06:08 +00:00
Ian Lance Taylor
7b4b96f248 cmd/link: add -msan option
The -msan option causes the linker to link against the runtime/msan
package in order to use the C/C++ memory sanitizer.

This CL passes tests but is not usable by itself.  The actual
runtime/msan package, and support for -msan in the go tool and the
compiler, and tests, are in separate CLs.

Change-Id: I02c097393b98c5b80e40ee3dbc167a8b4d23efe0
Reviewed-on: https://go-review.googlesource.com/16161
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-10-21 14:40:07 +00:00
Matthew Dempsky
d4a7ea1b71 runtime: add stringStructOf helper function
Instead of open-coding conversions from *string to unsafe.Pointer then
to *stringStruct, add a helper function to add some type safety.
Bonus: This caught two **string values being converted to
*stringStruct in heapdump.go.

While here, get rid of the redundant _string type, but add in a
stringStructDWARF type used for generating DWARF debug info.

Change-Id: I8882f8cca66ac45190270f82019a5d85db023bd2
Reviewed-on: https://go-review.googlesource.com/16131
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-20 23:13:27 +00:00
Michael Hudson-Doyle
d66f6c2c86 cmd/link: centralize knowledge of size of fixed part of stack
Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). Part 2b of
preparing for that is to have all the code in the linker that needs to know
this size of this call a function to find out.

Change-Id: I246363840096db22e44beabbe38b61d60c1f31ad
Reviewed-on: https://go-review.googlesource.com/15675
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-19 20:28:16 +00:00
David Crawshaw
26205cb3c0 cmd/link: PIE executables for android/arm
For #10807

Change-Id: Ied826d06cb622edf6413b6f2cdcc46987ab0b05a
Reviewed-on: https://go-review.googlesource.com/16054
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-19 17:41:39 +00:00
Michael Hudson-Doyle
69a99ccc62 cmd/link: always disable lazy PLT resolution when dynamically linking Go
Go cannot allow lazy PLT resolution when calling between Go functions because
the lazy resolution can use more stack than is available. Lazy resolution is
disabled by passing -z now to the system linker, but unfortunately was only
passed when linking to a Go shared library. That sounds fine, but the shared
library containing the runtime is not linked to any other Go shared library but
calls main.init and main.main via a PLT, and before this fix this did use lazy
resolution. (For some reason this never caused a problem on intel, but it
breaks on ppc64le). Fortunately the fix is very simple: always pass -z now to
the system linker when dynamically linking Go.

Change-Id: I7806d40aac80dcd1e56b95864d1cfeb1c42614e2
Reviewed-on: https://go-review.googlesource.com/15870
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-17 01:01:42 +00:00
Ian Lance Taylor
a0c7f57903 cmd/link: remove -W option
The -W option has not worked since Go 1.3.  It is not documented.  When
it did work, it generated useful output, but it was for human viewing;
there was no reason to write a script that passes the -W option, so it's
unlikely that anybody is using it today.

Change-Id: I4769f1ffd308a48324a866592eb7fd79a4cdee54
Reviewed-on: https://go-review.googlesource.com/15701
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-10-09 21:30:44 +00:00
Ian Lance Taylor
bd7de94d7f cmd/link: pass -Wl,-z,nodelete when creating an ELF shared library
Go shared libraries do not support dlclose, and there is no likelihood
that they will suppose dlclose in the future.  Set the DF_1_NODELETE
flag to tell the dynamic linker to not attempt to remove them from
memory.  This makes the shared library act as though every call to
dlopen passed the RTLD_NODELETE flag.

Fixes #12582.
Update #11100.
Update #12873.

Change-Id: Id4b6e90a1b54e2e6fc8355b5fb22c5978fc762b4
Reviewed-on: https://go-review.googlesource.com/15605
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2015-10-08 19:51:29 +00:00
Michael Hudson-Doyle
a5cb76243a cmd/internal/obj, cmd/link, runtime: lots of TLS cleanup
It's particularly nice to get rid of the android special cases in the linker.

Change-Id: I516363af7ce8a6b2f196fe49cb8887ac787a6dad
Reviewed-on: https://go-review.googlesource.com/14197
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-08 00:21:30 +00:00
Michael Hudson-Doyle
3e6334e2e0 cmd/link: set the ELF headers of ARM executables that use cgo correctly
It is generally expected that the ELF flags of a dynamically linked executable
and the libraries it links against match. Go's linker currently always produces
executables with flags that do not declare a float abi (hard, soft) at all, but
when cgo is involved it is unlikely that this matches the system libraries
being linked against -- really the decision about ABI is made by the C compiler
during the invocation of cgo.

This change is basically a port of the code from binutils that parses the
".ARM.attributes" section to check for the tag that declares that the code is
built for the hard-float ABI.

Fixes #7094

Change-Id: I737c8f3b5ed4af545cfc3e86722d03eb83083402
Reviewed-on: https://go-review.googlesource.com/14860
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-10-06 07:05:51 +00:00
David Crawshaw
47ccf96a95 runtime: darwin/386 entrypoint for c-archive
Change-Id: Ic22597b5e2824cffe9598cb9b506af3426c285fd
Reviewed-on: https://go-review.googlesource.com/12412
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-10-02 11:45:52 +00:00
Marvin Stenger
550b7ccf77 cmd/link/internal/ld: removed some uses of stringsCompare
Only one use of stringsCompare is left. Cannot simply be replaced by
strings.Compare for bootstrapping reasons I guess.
Moving the function away from util.go to the actual destination data.go
also would not help much. So I left this one unchanged for readability and convenience.

Change-Id: I60d22fec0be8f8c47c80586436f9a550af59194e
Reviewed-on: https://go-review.googlesource.com/14953
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-09-24 15:05:04 +00:00
Michael Hudson-Doyle
9a6a8a0586 cmd/link: fix addition of -Wl,-z,relro
Not sure how I managed to do this, or get it past review.

Change-Id: I141b97ef8e09dcc9c910c45493a584a3dced2b28
Reviewed-on: https://go-review.googlesource.com/14634
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-09-16 21:16:13 +00:00
Michael Hudson-Doyle
b0344e9fd5 cmd/internal/obj, cmd/link, runtime: a saner model for TLS on arm
this leaves lots of cruft behind, will delete that soon

Change-Id: I12d6b6192f89bcdd89b2b0873774bd3458373b8a
Reviewed-on: https://go-review.googlesource.com/14196
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-09-10 19:49:13 +00:00
Michael Hudson-Doyle
f7b66fffc5 cmd/dist, cmd/link: force external linking for shared libs on arm
Also run testcshared.

Fixes #12425

Change-Id: I5baea8d772d3462f945aab96260b4197dbb20c0a
Reviewed-on: https://go-review.googlesource.com/14143
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-09 01:42:22 +00:00
Michael Hudson-Doyle
5cbca8d84b cmd/internal/ld: put read-only relocated data into .data.rel.ro when making a shared object
Currently Go produces shared libraries that cannot be shared between processes
because they have relocations against the text segment (not text section). This
fixes this by moving some data to sections with magic names recognized by the
static linker.

The change in genasmsym to add STYPELINK to the switch should fix things on
darwin/arm64.

Fixes #10914
Updates #9210

Change-Id: Iab4a6678dd04cec6114e683caac5cf31b1063309
Reviewed-on: https://go-review.googlesource.com/14306
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-08 23:34:16 +00:00
Michael Hudson-Doyle
69a143e388 cmd/internal/obj: remove dead code and small cleanups
Change-Id: I88fa0cc245a2141af04acced8716e08b1133abd1
Reviewed-on: https://go-review.googlesource.com/14350
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-08 21:04:43 +00:00
Shawn Walker-Salas
4f74de1e4d cmd/go: fix Go buildid reading on Solaris
TestNoteReading fails on Solaris with linkmode=external due to some
assumptions made about how ELF .note sections are written by some
linkers.

On current versions of Solaris and older derivatives, SHF_ALLOC is
intentionally ignored for .note sections unless the .note section is
assigned to the text segment via a mapfile.  Also, if .note sections
are assigned to the text segment, no PT_NOTE program header will be
created thwarting Go's attempts at attempting to quickly find the
.note.

Furthermore, Go assumes that the relevant note segment will be placed
early in the file while the Solaris linker currently places the note
segment last in the file, additionally thwarting Go's optimisation
attempts that read only the first 16KB of the file to find the
buildid.

The fix is to detect when the note section is outside of the first
16KB of the file and then fallback to additionally reading that
section of the file.  This way, in future versions of Solaris when
this linking behaviour is changed, the fast path will always succeed
and we'll only be slower if it fails; likewise, any other linker that
does this will also just work.

Fixes #12178

Change-Id: I61c1dc3f744ae3ad63938386d2ace8a432c0efe1
Reviewed-on: https://go-review.googlesource.com/14210
Run-TryBot: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
2015-09-04 20:01:09 +00:00
Dave Cheney
e49b2460a4 Revert "cmd/internal/ld: put read-only relocated data into .data.rel.ro when making a shared object"
This reverts commit 2c2cbb69c8.

Broke darwin/arm64

Change-Id: Ibd2dea475d6ce6a8b4b40e2da19a83fc0514025d
Reviewed-on: https://go-review.googlesource.com/14301
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-04 19:47:36 +00:00
Shenghou Ma
821e124c24 cmd/link/internal/ld: align PE .text section to 32-byte when external linking
Some symbols, for example, masks requires 16-byte alignment, and
they are placed in the text section. Before this change, the text
section is only aligned to 4-byte, and it's making masks unaligned.

Fixes #12415.

Change-Id: I7767778d1b4f7d3e74c2719a02848350782a4160
Reviewed-on: https://go-review.googlesource.com/14166
Run-TryBot: Minux Ma <minux@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-04 05:27:02 +00:00
Michael Hudson-Doyle
2c2cbb69c8 cmd/internal/ld: put read-only relocated data into .data.rel.ro when making a shared object
Currently Go produces shared libraries that cannot be shared between processes
because they have relocations against the text segment (not text section). This
fixes this by moving some data to sections with magic names recognized by the
static linker.

Fixes #10914
Updates #9210

Change-Id: I7178daadc0ae87953d5a084aa3d580f4e3b46d47
Reviewed-on: https://go-review.googlesource.com/10300
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-04 05:25:10 +00:00
Michael Hudson-Doyle
06da8fd84a cmd/link: only embed runtime.goarm in the module that contains the runtime package
And do it properly so freebsd and nacl still work.

Change-Id: I6f9f30e93ceae6dee59215ed608c6a158bdbdbb0
Reviewed-on: https://go-review.googlesource.com/14280
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-09-04 02:20:47 +00:00
Michael Hudson-Doyle
c788a8e05d Revert "cmd/link: only embed runtime.goarm in the module that contains the runtime package"
This reverts commit bf99d8f843.

Change-Id: Id4374ed35802cfbfe11e015ccd9526d3497dc8cc
Reviewed-on: https://go-review.googlesource.com/14239
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-09-03 21:20:53 +00:00
Michael Hudson-Doyle
bf99d8f843 cmd/link: only embed runtime.goarm in the module that contains the runtime package
Change-Id: Ia18984343ca4ced3671d967ff9a5b0e32874430c
Reviewed-on: https://go-review.googlesource.com/14220
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-09-03 16:22:21 +00:00
Michael Hudson-Doyle
9e6ba37b86 cmd/internal/obj: some platform independent bits of proper toolchain support for thread local storage
Also simplifies some silliness around making the .tbss section wrt internal
vs external linking. The "make TLS make sense" project has quite a few more
steps to go.

Issue #11270

Change-Id: Ia4fa135cb22d916728ead95bdbc0ebc1ae06f05c
Reviewed-on: https://go-review.googlesource.com/13990
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-09-03 14:06:07 +00:00
Michael Hudson-Doyle
e92d0d82e0 cmd/link: remove some dead code
Change-Id: I125a12a2cb7e792f357e4d841f55c0bed2971dce
Reviewed-on: https://go-review.googlesource.com/14140
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-09-01 16:28:49 +00:00
Michael Hudson-Doyle
af799d94f9 cmd/link: pass value being relocated to archreloc
And clean up the mess on arm64 (the mess on arm is too confusing).

See issue #10050

Change-Id: I2ce813fe8646d4e818eb660612a7e4b2bb04de4c
Reviewed-on: https://go-review.googlesource.com/13884
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-08-31 00:07:59 +00:00
Michael Hudson-Doyle
af78482d6b cmd/compile, cmd/link, reflect, runtime: remove type.zero field
No longer used after previous hashmap change.

Change-Id: I558470f872281e84a78406132df4e391d077b833
Reviewed-on: https://go-review.googlesource.com/13785
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-08-26 00:28:17 +00:00
Michael Hudson-Doyle
7f9e443d9c cmd/link: call moduledata symbols "local.moduledata" if they are created by the linker
This was always a bit confusing, but it also fixes a problem: runtime.firstmoduledata
was always overridden in the linker to be a local symbol but cmd/internal/obj had
already rewritten code accessing it to access it via the GOT. This works on amd64, but
causes link failures on other platforms (e.g. arm64).

Change-Id: I9b8153af74b4d0f092211d63a000d15818f39773
Reviewed-on: https://go-review.googlesource.com/13786
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-08-25 23:48:12 +00:00
Russ Cox
8ce80ce87d cmd/link: make -a output not crash
Fixes #12107.

Change-Id: I62f1b6ac9fb6f2cfa3472253dc1c6f7b7d2a6faf
Reviewed-on: https://go-review.googlesource.com/13448
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-08-11 19:12:59 +00:00
Russ Cox
66cb5cd530 cmd/link: increase ELFRESERVE to a full page
Etcd and kubernetes have hit this.
See  https://bugzilla.redhat.com/show_bug.cgi?id=1248071

Change-Id: I6231013efa0a19ee74f7ebacd1024adb368af83a
Reviewed-on: https://go-review.googlesource.com/12951
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-31 02:18:35 +00:00
Russ Cox
767e065809 cmd/link: fix nosplit stack overflow checks
The nosplit stack overflow checks were confused about morestack.
The comment about not having correct SP information at the call
to morestack was true, but that was a real bug, not something to
work around. I fixed that problem in CL 12144. With that fixed,
no need to special-case morestack in the way done here.

This cleanup and simplification of the code was the first step
to fixing a bug that happened when I started working on the
arm64 frame size adjustments, but the cleanup was sufficient
to make the bug go away.

For #9880.

Change-Id: I16b69a5c16b6b8cb4090295d3029c42d606e3b9b
Reviewed-on: https://go-review.googlesource.com/12846
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 21:36:16 +00:00
Ian Lance Taylor
ad84f84cb4 cmd/link: don't generate .exe extension for external Windows link
On Windows, gcc -o foo will generate foo.exe.  Prevent that from
happening by adding a final '.' if necessary so that GCC thinks that
the file already has an extension.

Also remove the initial output file when doing an external link, and
use mayberemoveoutfile, not os.Remove, when building an archive
(otherwise we will do the wrong thing for -buildmode=c-archive -o
/dev/null).

I didn't add a test, as it requires using cgo and -o on Windows.

Fixes #11725.

Change-Id: I6ea12437bb6b4b9b8ee5c3b52d83509fa2437b2d
Reviewed-on: https://go-review.googlesource.com/12243
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-23 17:49:44 +00:00
Russ Cox
5659964d67 cmd/link: write combined dwarf file to same directory as output file
Fixes #11681.

Change-Id: I679d71ed25ac585af7d43611be01c1a0c4807871
Reviewed-on: https://go-review.googlesource.com/12554
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-23 03:52:20 +00:00
Russ Cox
0acecb7164 cmd/link: elide individual gcbits symbols
Same as we do for string symbols.

Fixes #11583.

Change-Id: Ia9264f6faf486697d987051b7f9851d37d8ad381
Reviewed-on: https://go-review.googlesource.com/12531
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-22 20:27:24 +00:00
Ian Lance Taylor
e9fcd6ed2b cmd/link: if -B option was used, pass it to the external linker
Fixes #10607.

Change-Id: Ib294cf65b07103b60f62b86b21ff2d07b25136fe
Reviewed-on: https://go-review.googlesource.com/12242
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-21 03:57:55 +00:00
Brad Fitzpatrick
2ae77376f7 all: link to https instead of http
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.

I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.

Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
2015-07-11 14:36:33 +00:00
Matthew Dempsky
1082e2390e cmd/link/internal/ld: stricter object file decoding
Instead of silently truncating integers to their expected range, check
that they're within range and emit errors if not.  Intended to help
narrow down the cause of issue #11617.

Change-Id: Ia7b577270f8438ca7479262702371e26277f1ea7
Reviewed-on: https://go-review.googlesource.com/12050
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-10 22:01:54 +00:00
Russ Cox
6f80e5edf4 cmd/link: reject data size > 2 GB
We can't address more than this on amd64 anyway.

Fixes #9862.

Change-Id: Ifb1abae558e2e1ee2dc953a76995f3f08c60b1df
Reviewed-on: https://go-review.googlesource.com/11715
Reviewed-by: Austin Clements <austin@google.com>
2015-06-30 19:40:39 +00:00
Russ Cox
69f0d4c6be cmd/link: detect -X setting non-string variable
Fixes #9621.

Change-Id: Ib9c6001378364af899f57fd4b89fb23af2042923
Reviewed-on: https://go-review.googlesource.com/11694
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-06-29 20:28:36 +00:00
Russ Cox
34846aef78 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>
2015-06-29 19:49:38 +00:00
Russ Cox
434e0bc0a0 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.

Fixes #10747.
Fixes #11396.

Change-Id: I13592e78017969fc22979fa902e19e1b151d41b1
Reviewed-on: https://go-review.googlesource.com/11657
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
2015-06-29 16:07:14 +00:00
Keith Randall
214c7a2c43 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:

container _/home/khr/sandbox/symtab/misc/cgo/test(.text)<74>
container _/home/khr/sandbox/symtab/misc/cgo/test/issue8828(.text)<75>
container _/home/khr/sandbox/symtab/misc/cgo/test/issue9026(.text)<76>
container runtime/cgo(.text)<77>

I'm not sure this is the right fix.  In particular I can't reproduce
the original problem.  Anyone have a repro they can try and see if
this fix works?

Fixes #10747
Fixes #11396

Change-Id: Id8b016389d33348b4a791fdcba0f9db8ae71ebf3
Reviewed-on: https://go-review.googlesource.com/11652
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-29 02:54:09 +00:00
David Crawshaw
58578de0dc cmd/link: no dwarf on darwin/arm
Partial revert of cl/10284 to get -buildmode=c-archive working for
darwin/arm.

Manually tested with iostest.bash while builder is offline.

Change-Id: I98e4e209765666e320e680e11151fce59e2afde9
Reviewed-on: https://go-review.googlesource.com/11306
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
2015-06-27 21:32:38 +00:00
Srdjan Petrovic
cc6554f750 cmd/link/internal/ld, cmd/go: -buildmode=c-shared support for darwin/amd64
All of the heavy-lifting was done by minux@, with his external-linking support
for darwin/arm64: golang.org/cl/8781

Change-Id: I7c9fbc19246f418c065c92fb2c13c00026ff0f82
Reviewed-on: https://go-review.googlesource.com/11127
Run-TryBot: Srdjan Petrovic <spetrovic@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-19 20:28:01 +00:00
Shenghou Ma
3925a7c5db all: switch to the new deprecation convention
While we're at it, move some misplaced comment blocks around.

Change-Id: I1847d7f1ca1dbb8e5de737203c4ed6c66e112508
Reviewed-on: https://go-review.googlesource.com/10188
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-18 19:16:23 +00:00
Michael Hudson-Doyle
a5f57d7950 cmd/link: when reading symbols from a shared library, allow duplicates when they are both in bss
This makes the behaviour match what happens when duplicate symbols are read
from regular object files and fixes errors about cgoAlwaysFalse when linking
an executable that uses cgo against a shared library.

Change-Id: Ibb8cd8fe3f7813cde504b7483f1e857868d7e063
Reviewed-on: https://go-review.googlesource.com/11117
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-16 22:33:36 +00:00
Ainar Garipov
7f9f70e5b6 all: fix misprints in comments
These were found by grepping the comments from the go code and feeding
the output to aspell.

Change-Id: Id734d6c8d1938ec3c36bd94a4dbbad577e3ad395
Reviewed-on: https://go-review.googlesource.com/10941
Reviewed-by: Aamir Khan <syst3m.w0rm@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-06-11 14:18:57 +00:00
Alex Brainman
ab08f79af3 cmd/link: stop linker crashing with -s flag on windows
Update #10254

Change-Id: I3ddd26607813ca629e3ab62abf87dc5ab453e36f
Reviewed-on: https://go-review.googlesource.com/10835
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-10 06:49:23 +00:00
Hyang-Ah (Hana) Kim
c9778ec302 cmd/link/internal/ld: include table of contents of c-archive output.
Change-Id: If11621985c0a5a1f2133cdc974f37fd944b93e5e
Reviewed-on: https://go-review.googlesource.com/10808
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-09 00:55:11 +00:00
Russ Cox
aefa6cd1f9 cmd/link: delete dead flags
Also fix the interaction between -buildmode and -shared.
It's okay for -shared to change the default build mode,
but it's not okay for it to silently override an explicit -buildmode=exe.

Change-Id: Id40f93d140cddf75b19e262b3ba4856ee09a07ba
Reviewed-on: https://go-review.googlesource.com/10315
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-06-05 04:55:53 +00:00
Russ Cox
12795c02f3 cmd/link: deprecate -X name value in favor of -X name=value
People invoking the linker directly already have to change their scripts
to use the new "go tool link", so this is a good time to make the -X flag
behave like all other Go flags and take just a single argument.

The old syntax will continue to be accepted (it is rewritten into the new
syntax before flag parsing). Maybe some day we will be able to retire it.

Even if we never retire the old syntax, having the new syntax at least
makes the rewriting much less of a kludge.

Change-Id: I91e8df94f4c22b2186e81d7f1016b8767d777eac
Reviewed-on: https://go-review.googlesource.com/10310
Reviewed-by: Rob Pike <r@golang.org>
2015-06-05 04:55:41 +00:00
Russ Cox
630930c35e cmd/compile, cmd/link: add docs
These are the Go 1.4 docs but refreshed for Go 1.5.
The most sigificant change is that all references to the Plan 9 toolchain are gone.
The tools no longer bear any meaningful resemblance.

Change-Id: I44f5cadb832a982323d7fee0b77673e55d761b35
Reviewed-on: https://go-review.googlesource.com/10298
Reviewed-by: Rob Pike <r@golang.org>
2015-06-05 04:42:35 +00:00
Russ Cox
9ae3c560b9 cmd/link: implement -buildid for non-ELF binaries
Non-ELF binary formats are much less flexible and typically do not
have a good place to store the build ID.

We store it as raw bytes at the beginning of the text segment.

The only system I know of that will be upset about this is NaCl,
and NaCl is an ELF system and does not use this.

For #11048.

Change-Id: Iaa7ace703c4cf36392e752eea9b55e2ce49e9826
Reviewed-on: https://go-review.googlesource.com/10708
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-05 04:06:46 +00:00
Russ Cox
ac1f48e2f6 cmd/link: add -buildid flag to write Go build ID to ELF output, same as cmd/compile
Other binary formats to follow.

Using our own note instead of the GNU build ID note because
we are not the GNU project, and I can't guarantee that the semantics
of our note and the semantics of the GNU note will match forever.
(Also they don't match today.)

For #11048.

Change-Id: Iec7e5a2e49d52b6d3a51b0aface2de7c77a45491
Reviewed-on: https://go-review.googlesource.com/10706
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-05 04:02:26 +00:00
Russ Cox
a2c50ece2b cmd/link: add -h flag, for debugging, same as cmd/compile
Change-Id: I3c9b05879fe0b6e94b63e9b65e4411ba2a917134
Reviewed-on: https://go-review.googlesource.com/10705
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-05 04:00:11 +00:00
Russ Cox
7e27625e25 cmd/go, cmd/link: use "Go" not "GO" as ELF note identifier
Change-Id: I038e892725836ab7718f7638e8ad5712953f2cb5
Reviewed-on: https://go-review.googlesource.com/10704
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-05 03:59:46 +00:00
Josh Bleecher Snyder
ca19e55f9a cmd/link: make stkcheck more flexible
stkcheck is flow-insensitive: It processes calls in PC order.
Since morestack was always the first call in a function,
it was a safe, conservative approximation to simply adjust stack
space as we went, recognizing morestack when it showed up.

Subsequent CLS will rearrange the function prologue;
morestack may no longer be the first call in a function.

Introducing flow-sensitivity to stkcheck would allow this,
and possibly allow a smaller stackguard.
It is also a high risk change and possibly expensive.

Instead, assume that all calls to morestack occur as
part of the function prologue, no matter where they
are located in the program text.

Updates #10587.

Change-Id: I4dcdd4256a980fc4bc433a68a10989ff57f7034f
Reviewed-on: https://go-review.googlesource.com/10496
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-06-04 03:14:23 +00:00
Russ Cox
c345f7ff95 cmd/go: make test.bash pass again
Fixes #8809.

Change-Id: Id443fd406e9c611d5dfabc71a98eb71d1cc0972c
Reviewed-on: https://go-review.googlesource.com/9150
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-06-03 20:33:30 +00:00
Ryan Brown
5ee552815c cmd/link/internal/ld: Skip combining dwarf for darwin/arm.
Change-Id: I3a6df0a76d57db7cb6910f4179a6ce380f219a37
Reviewed-on: https://go-review.googlesource.com/10442
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-28 12:04:35 +00:00
Michael Hudson-Doyle
c949cff6a7 cmd/internal/ld: do not depend on local symbols to read a type's gcdata
We already read the address of a gcmask/gcprog out of the type data, but I
didn't know how many bytes to read. But it turns out that it's easy to
calculate, so change to do that. This means that we no longer depend on the
local symbols being present, allowing me to strip the shared libraries for
distribution and make them a lot smaller.

As a bonus, this makes LSym another 24 bytes smaller, down to 296 bytes now.

Change-Id: I379d359e28d63afae6753efd23efdf1fbb716992
Reviewed-on: https://go-review.googlesource.com/10377
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-27 14:11:16 +00:00
Michael Hudson-Doyle
bcc1870fcf cmd/internal/ld: store the libraries a shared library was linked against in a note
The motivation for this is the innocuous looking test case that is added. This
creates a stack exe -> libdep2.so -> libdep.so -> libruntime.so. The problem
comes from the fact that a function from libdep.so gets inlined all the way
into exe. This (unsurprisingly) means that the object file for exe references
symbols from libdep.so, which means that -ldep needs to be passed when linking
exe and it isn't. The fix is simply to pass it -- there is no harm in passing
it when it's not needed.

The thing is, it's not clear at all in the current code to see how the linker
can know that libdep2 is linked against libdep. It could look through the
DT_NEEDED entries in libdep2 and try to guess which are Go libraries, but it
feels better to be explicit. So this adds another SHT_NOTE section that lists
the shared libraries a shared library was linked against, and makes sure the
complete set of depended upon shared libraries is passed to the external
linker.

Change-Id: I79aa6f98b4db4721d657a7eb7b7f062269bf49e2
Reviewed-on: https://go-review.googlesource.com/10376
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-27 13:25:32 +00:00
Michael Hudson-Doyle
65518032b9 cmd/link/internal/ld: put abi hash into a note
This makes for a more stable API for tools (including cmd/link itself) to
extract the abi hash from a shared library and makes it possible at all for a
library that has had the local symbol table removed.

The existing note-writing code only supports writing notes into the very start
of the object file so they are easy to find in core dumps. This doesn't apply
to the "go" notes and means that all notes have to fit into a fixed size
budget. That's annoying now we have more notes (and the next CL will add
another one) so this does a little bit of work to make adding notes that do not
have to go at the start of the file easier and moves the writing of the package
list note over to that mechanism, which lets me revert a hack that increased
the size budget mentioned above for -buildmode=shared builds.

Change-Id: I6077a68d395c8a2bc43dec8506e73c71ef77d9b9
Reviewed-on: https://go-review.googlesource.com/10375
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-27 04:48:29 +00:00
Michael Hudson-Doyle
cf2736c4c5 cmd/link: replace interface{} fields with concrete types
The LSym.Section and Section.Elfsect fields were defined as interface{} but
always had the same concrete type (*Section and *ElfShdr respectively) so just
define them with that type. Reduces size of LSym from 328 to 320 bytes and
reduces best-of-10 maxresident size from 246028k to 238036k when linking
libstd.so.

Change-Id: Ie7112c53e4c2c7ce5fe233b81372aa5633f572e8
Reviewed-on: https://go-review.googlesource.com/10410
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-27 04:03:32 +00:00
Ian Lance Taylor
b2f95a167a cmd/link/internal/amd64: -buildmode=c-archive forces external link mode
At some point this code should probably move to cmd/link/internal/ld,
but at least for now just handle c-archive like c-shared.

Change-Id: Ic17656529cb0fe189a37f15e670350ab13bb5276
Reviewed-on: https://go-review.googlesource.com/10385
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-05-26 21:49:45 +00:00
Ian Lance Taylor
714291f2d8 cmd/link/internal/ld: if -v, display external linker output
It can be useful when debugging to be able to see what the external
linker is doing even when it succeeds.  In particular this permits
passing -v to the external linker to see precisely what it is doing.

Change-Id: Ifed441912d97bbebea20303fdb899e140b380215
Reviewed-on: https://go-review.googlesource.com/10363
Reviewed-by: Minux Ma <minux@golang.org>
2015-05-26 03:59:14 +00:00
Russ Cox
cf932cd897 all: retire architecture letter in file names, public API
This CL removes the remaining visible uses of the "architecture letter" concept.
(They are no longer in tool names nor in source directory names.)

Because the architecture letter concept is now gone, delete GOCHAR
from "go env" output, and change go/build.ArchChar to return an
error always.

The architecture letter is still used in the compiler and linker sources
as a clumsy architecture enumeration, but that use is not visible to
Go users and can be cleaned up separately.

Change-Id: I4d97a38f372003fb610c9c5241bea440d9dbeb8d
Reviewed-on: https://go-review.googlesource.com/10289
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:32:17 +00:00
Russ Cox
17eba6e6b7 cmd/compile, cmd/link: create from 5g, 5l, etc
Trivial merging of 5g, 6g, ... into go tool compile,
and similarlly 5l, 6l, ... into go tool link.
The files compile/main.go and link/main.go are new.
Everything else in those directories is a move followed by
change of imports and package name.

This CL breaks the build. Manual fixups are in the next CL.

See golang-dev thread titled "go tool compile, etc" for background.

Change-Id: Id35ff5a5859ad9037c61275d637b1bd51df6828b
Reviewed-on: https://go-review.googlesource.com/10287
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:31:51 +00:00
Russ Cox
2a141dedc4 cmd/link: move to cmd/newlink
In preparation for making the current linker cmd/link.
If cmd/newlink is ever completed, it can be moved back.

See golang-dev thread titled "go tool compile, etc" for background.

Change-Id: I4029580f470038240c5181a37ea4202ba971f9ef
Reviewed-on: https://go-review.googlesource.com/10286
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:31:40 +00:00
Michael Hudson-Doyle
68f5570032 cmd/link, cmd/internal/goobj: update constants, regenerate testdata
The constants in cmd/internal/goobj had gone stale (we had three copies of
these constants, working on reducing that was what got me to noticing this).

Some of the changes to link.hello.darwin.amd64 are the change from absolute
to %rip-relative addressing, a change which happened quite a while ago...

Depends on http://golang.org/cl/9113.

Fixes #10501.

Change-Id: Iaa1511f458a32228c2df2ccd0076bb9ae212a035
Reviewed-on: https://go-review.googlesource.com/9105
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-04-22 20:32:16 +00:00
Russ Cox
3e7d4f11c0 debug/goobj: move to cmd/internal/goobj
debug/goobj is not ready to be published but it is
needed for the various binary-reading commands.
Move to cmd/internal/goobj.

(The Go 1.3 release branch deleted it, but that's not
an option anymore due to the command dependencies.
The API is still not vetted nor terribly well designed.)

LGTM=adg, dsymonds
R=adg, dsymonds
CC=golang-codereviews
https://golang.org/cl/174250043
2014-11-16 20:52:45 -05:00
Matthew Dempsky
2c110a11e0 cmd/{ld,link,objdump}, runtime, debug/gosym: move linker-defined symbols into runtime package
Fixes #8092.

LGTM=rsc
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/126790043
2014-08-27 20:15:05 -04:00
Matthew Dempsky
2a679f8e3a cmd/link: fix testdata generation
Fixes #8494.

LGTM=rsc
R=golang-codereviews, gobot, rsc, evankroske
CC=golang-codereviews
https://golang.org/cl/123040043
2014-08-24 20:31:16 -04:00
Rob Pike
8bca148a3e all: copy cmd/ld/textflag.h into pkg/GOOS_GOARCH
The file is used by assembly code to define symbols like NOSPLIT.
Having it hidden inside the cmd directory makes it hard to access
outside the standard repository.
Solution: As with a couple of other files used by cgo, copy the
file into the pkg directory and add a -I argument to the assembler
to access it. Thus one can write just
        #include "textflag.h"
in .s files.

The names in runtime are not updated because in the boot sequence the
file has not been copied yet when runtime is built. All other .s files
in the repository are updated.

Changes to doc/asm.html, src/cmd/dist/build.c, and src/cmd/go/build.go
are hand-made. The rest are just the renaming done by a global
substitution. (Yay sam).

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/128050043
2014-08-12 17:04:45 -07:00
Matthew Dempsky
eae9fee3bf cmd/link: fix zig-zag decoding
The >>1 shift needs to happen before converting to int32, otherwise
large values will decode with an incorrect sign bit.

The <<31 shift can happen before or after, but before is consistent
with liblink and the go12symtab doc.

Bug demo at http://play.golang.org/p/jLrhPUakIu

LGTM=rsc
R=golang-codereviews, minux, rsc
CC=golang-codereviews
https://golang.org/cl/119630043
2014-08-11 13:53:38 -04:00
Robert Hencke
d46134830f src: fix issues found by go vet std
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/96850043
2014-04-26 19:54:48 -07:00
Russ Cox
5e8c922625 liblink, cmd/ld: reenable nosplit checking and test
The new code is adapted from the Go 1.2 nosplit code,
but it does not have the bug reported in issue 7623:

g% go run nosplit.go
g% go1.2 run nosplit.go
BUG
rejected incorrectly:
        main 0 call f; f 120

        linker output:
        # _/tmp/go-test-nosplit021064539
        main.main: nosplit stack overflow
                120	guaranteed after split check in main.main
                112	on entry to main.f
                -8	after main.f uses 120

g%

Fixes #6931.
Fixes #7623.

LGTM=iant
R=golang-codereviews, iant, ality
CC=golang-codereviews, r
https://golang.org/cl/88190043
2014-04-16 22:08:00 -04:00
Russ Cox
cc08d9232c liblink: add leaf bit to object file format
Without the leaf bit, the linker cannot record
the correct frame size in the symbol table, and
then stack traces get mangled. (Only for ARM.)

Fixes #7338.
Fixes #7347.

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/88550043
2014-04-16 17:11:44 -04:00
Russ Cox
8d39e55c65 liblink: remove arch-specific constants from file format
The relocation and automatic variable types were using
arch-specific numbers. Introduce portable enumerations
instead.

To the best of my knowledge, these are the only arch-specific
bits left in the new object file format.

Remove now, before Go 1.3, because file formats are forever.

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/87670044
2014-04-14 15:54:20 -04:00
Russ Cox
0e8de61d73 liblink, cmd/link: add version number to object file
There are changes we know we want to make, but not before Go 1.3
Add a version number so that we can make them more easily later.

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/87670043
2014-04-14 13:20:51 -04:00
Rick Arnold
86ac618145 cmd/link: change cloneProg to return the cloned value
The code was returning the original value rather than the cloned value
resulting in the tests not being repeatable.

Fixes #7111.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/65720045
2014-02-18 17:59:44 -08:00
Nigel Tao
d2f61cc660 cmd/link: fix comment typo.
LGTM=dsymonds
R=dsymonds
CC=golang-codereviews
https://golang.org/cl/64100045
2014-02-18 13:04:59 +11:00
Russ Cox
2a2a3baac4 cmd/link: add testdata/pclntab.6 (fix build)
Sorry, "hg status" hides .6 files by default.
We should probably fix that.

TBR=iant
CC=golang-codereviews
https://golang.org/cl/55290043
2014-01-21 17:12:30 -05:00
Russ Cox
a453f28c70 cmd/link: pclntab generation
R=iant
CC=golang-codereviews
https://golang.org/cl/53820043
2014-01-21 13:47:47 -05:00
Russ Cox
6e8b4920c1 cmd/link: fix build
The golden file for link.hello.darwin.amd64
was a little ahead of the checked-in code.

R=iant
TBR=iant
CC=golang-codereviews
https://golang.org/cl/51870043
2014-01-13 23:20:53 -05:00
Russ Cox
7dcc652f10 cmd/link: implement dead code removal
R=iant
CC=golang-codereviews
https://golang.org/cl/51470043
2014-01-13 23:08:10 -05:00
Russ Cox
7cecac3cbb cmd/link: implement and test automatic symbols
Related changes included in this CL:

 - Add explicit start symbol to Prog.
 - Add omitRuntime bool to Prog.
 - Introduce p.Packages[""] to hold automatic symbols
 - Add SymOrder to Prog to preserve symbol order.
 - Add layout test (and fix bug that was putting everything in text section).

R=iant
CC=golang-codereviews
https://golang.org/cl/51260045
2014-01-13 23:07:57 -05:00
Russ Cox
9c1aa658bf cmd/link: replace golden binary files with hex dumps
The hex dumps will diff better, and I hope they will avoid
a repeat of http://bugs.debian.org/716853.

The CL will probably show the testdata diffs as "binary",
but in fact the binary versions are being replaced by
textual hex dumps (output of hexdump -C).

R=iant
CC=golang-codereviews
https://golang.org/cl/51000044
2014-01-13 23:07:40 -05:00
Russ Cox
8449863d31 cmd/link: Mach-O (OS X) file formatter
See CL 48870044 for basic structure.

R=iant
CC=golang-codereviews
https://golang.org/cl/48910043
2014-01-09 19:29:29 -05:00
Russ Cox
146897b031 cmd/link: intial skeleton of linker written in Go
R=iant
CC=golang-codereviews
https://golang.org/cl/48870044
2014-01-09 19:29:10 -05:00