1
0
mirror of https://github.com/golang/go synced 2024-11-13 20:00:23 -07:00
Commit Graph

562 Commits

Author SHA1 Message Date
Hiroshi Ioka
2763672ecb cmd/link: show native relocation type name in error messages
Change-Id: I7f7b1e7ef832d53a93562b08ae914d023247c2c0
Reviewed-on: https://go-review.googlesource.com/56312
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-17 23:41:25 +00:00
Hiroshi Ioka
064ae118c1 cmd/link: correct runtime/cgo detection for -linkshared
Current code detect runtime/cgo iff the package or sub packages imports
runtime/cgo directly. However, when we are using linkshared, imported
shared libraries might have already included runtime/cgo.
This CL handles later case by looking an actual runtime/cgo symbol.

Change-Id: I35e7dfdb5e1a939eafc95a0259ee1af9782bc864
Reviewed-on: https://go-review.googlesource.com/56310
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-17 01:12:30 +00:00
David du Colombier
8127dbf76a cmd/link: skip TestFieldOverlap on Plan 9
TestSizes has been added in CL 50170. This test is
failing on Plan 9 because executables don't have
a DWARF symbol table.

Fixes #21480.

Change-Id: I51079abdc18ad944617bdbcfe2dad970a0cea0f2
Reviewed-on: https://go-review.googlesource.com/56210
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-16 19:04:00 +00:00
Keith Randall
e70fae8a64 cmd/link: fix bad dwarf for sudog<T>
The DWARF entries for type-specific sudog entries used the
channel value type instead of a pointer-to-value type for the elem field.

Fixes #21094

R=go1.10

Change-Id: I3f63a5664f42b571f729931309f2c9f6f38ab031
Reviewed-on: https://go-review.googlesource.com/50170
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-16 16:22:20 +00:00
Alex Brainman
a9257b6b69 cmd/link: delete shNames
Change-Id: Ie5d12ba4105fec17551637d066d0dffd508f74a4
Reviewed-on: https://go-review.googlesource.com/55261
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-16 05:13:18 +00:00
Alex Brainman
6aa386686c cmd/link: delete addpesection
Change-Id: Iee9db172d28d4d372fa617907078a494e764bf12
Reviewed-on: https://go-review.googlesource.com/55260
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-16 05:12:11 +00:00
Alex Brainman
babc5b1dd6 cmd/link: use peSection everywhere
Change-Id: I4d4e8452b9b9e628f3ea8b2b727ad63ec2a1dd31
Reviewed-on: https://go-review.googlesource.com/55259
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-16 05:11:09 +00:00
Alex Brainman
2c2b172377 cmd/link: add peSection
Change-Id: Id3aeeaeaacf5f079fb2ddad579f2f209b7fc0e06
Reviewed-on: https://go-review.googlesource.com/55258
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-16 05:10:22 +00:00
Alex Brainman
20832e6d4b cmd/link: introduce and use peFile and peStringTable
Change-Id: Icd13b32d35cde474c9292227471f916a64af88eb
Reviewed-on: https://go-review.googlesource.com/55257
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-16 05:09:08 +00:00
David du Colombier
583a941d4e cmd/link: skip TestSizes on Plan 9
TestSizes has been added in CL 55551. This test is
failing on Plan 9 because executables don't have
a DWARF symbol table.

Fixes #21453.

Change-Id: I560611b49aea5417e8c5ac0cec6c7882bd9f8335
Reviewed-on: https://go-review.googlesource.com/55692
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
2017-08-15 10:10:42 +00:00
Russ Cox
ef6978b218 cmd/link: implement R_X86_64_PC64 relocations
Change-Id: I1d7bd5cff7350a4e0f78b8efc8406e79c74732d1
Reviewed-on: https://go-review.googlesource.com/55370
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-15 04:20:44 +00:00
Hiroshi Ioka
1ee701e857 cmd/link: improve error message
ld.SymKind and objabi.RelocType have string representations,
which is human friendly. Prefer to use it.

Change-Id: I458ee0ca5866be0db8462c36cd053561a8206c95
Reviewed-on: https://go-review.googlesource.com/55253
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-15 00:28:27 +00:00
Hiroshi Ioka
90ffc40e4f cmd/link: correct Mach-O file flag
Only set MH_NOUNDEFS if there are no undefined symbols.
Doesn't seem to matter, but may as well do it right.

Change-Id: I6c472e000578346c28cf0e10f24f870e3a0de628
Reviewed-on: https://go-review.googlesource.com/55310
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-15 00:13:10 +00:00
Keith Randall
f4abbc0e61 cmd/link,compile: Provide size for func types
They are currently not given a size, which makes the DWARF reader
very confused. Particularly things like [4]func() get a size of -4, not 32.

Fixes #21097

Change-Id: I01e754134d82fbbe6567e3c7847a4843792a3776
Reviewed-on: https://go-review.googlesource.com/55551
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-14 23:53:27 +00:00
Hiroshi Ioka
1f8433c66a cmd/link: don't link the same dylib multiple times
Also, unexport Machoadddynlib

n=`go test -c crypto/x509 && otool -l x509.test | grep libSystem | wc -l`

Before this CL, n = 3.
After this CL, n = 1.

on my environment.

Change-Id: Ic7b8157435cc85086404860dc6c84eb0aecc5d19
Reviewed-on: https://go-review.googlesource.com/44771
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Avelino <t@avelino.xxx>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-14 18:48:28 +00:00
Hiroshi Ioka
b7c600d6ba cmd/go, cmd/link: enable buildmode=pie on darwin/amd64
Change some configurations to enable the feature. Also add the test.
This CL doesn't include internal linking support which is tentatively
disabled due to #18968. We could do that another day.

Fixes #21220

Change-Id: I601d2d78446d36332acc70be0d5b9461ac635208
Reviewed-on: https://go-review.googlesource.com/54790
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-14 18:45:21 +00:00
Hiroshi Ioka
5b43bbe63b cmd/link: prefer to use constants in macho.go
We might want to replace some linker's feature by debug/macho in future.
This CL gathers information of required constants.

Change-Id: Iea14abdb32709a4f5404a17874f9c925d29ba999
Reviewed-on: https://go-review.googlesource.com/55252
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-14 05:28:38 +00:00
Hiroshi Ioka
6424c40c22 cmd/link: don't emit default entry symbol in some situations
Also, fix comment.

Change-Id: Ieb7ba21f34730dc51ab45a652d225e4145d4b861
Reviewed-on: https://go-review.googlesource.com/54870
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-14 05:28:22 +00:00
Hiroshi Ioka
342d25fc05 cmd/link: remove redundant switch stmt
Change-Id: I5c4f8dc1e174b3438ef4fb509fac78d6e1b292c9
Reviewed-on: https://go-review.googlesource.com/54791
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Avelino <t@avelino.xxx>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-14 04:44:35 +00:00
Austin Clements
6f6a9398e2 Merge remote-tracking branch 'origin/dev.debug' into master
Change-Id: I85df2745af666b533f4f6f1d06f7c8e137590b5b
2017-08-11 12:17:43 -04:00
Hiroshi Ioka
d02647242d cmd/link: check magic header
Change-Id: I84b0e1d86728a76bc6a87fee4accf6fc43d87006
Reviewed-on: https://go-review.googlesource.com/54814
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-08-11 01:51:34 +00:00
Lynn Boger
3e7abf82e3 cmd/go,cmd/link: support buildmode c-shared on ppc64le
This change enables buildmode c-shared on ppc64le.

A bug was fixed in runtime/rt0_linux_ppc64le.s that was necessary to
make this work.  In _rt0_ppc64le_linux_lib, there is code to store
the value of r2 onto the caller's stack.  However, if this file
is compiled using a build mode that maintains the TOC address in
r2, then instructions will be inserted at the beginning of this
function to generate the r2 value for the callee, not the caller.
That means the r2 value for the callee is stored onto the caller's
stack.  If caller and callee don't have the same r2 values, then
the caller will restore the wrong r2 value after it returns.  This
situation can happen when using dlopen since the caller of this
function will be in ld64.so and will definitely have a different
TOC.

Updates #20756

Change-Id: I6e165e0d0716e73721bbbcc520e8302e4856e3ba
Reviewed-on: https://go-review.googlesource.com/53890
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-09 17:11:38 +00:00
Heschi Kreinick
4c54a047c6 [dev.debug] cmd/compile: better DWARF with optimizations on
Debuggers use DWARF information to find local variables on the
stack and in registers. Prior to this CL, the DWARF information for
functions claimed that all variables were on the stack at all times.
That's incorrect when optimizations are enabled, and results in
debuggers showing data that is out of date or complete gibberish.

After this CL, the compiler is capable of representing variable
locations more accurately, and attempts to do so. Due to limitations of
the SSA backend, it's not possible to be completely correct.

There are a number of problems in the current design. One of the easier
to understand is that variable names currently must be attached to an
SSA value, but not all assignments in the source code actually result
in machine code. For example:

  type myint int
  var a int
  b := myint(int)
and
  b := (*uint64)(unsafe.Pointer(a))

don't generate machine code because the underlying representation is the
same, so the correct value of b will not be set when the user would
expect.

Generating the more precise debug information is behind a flag,
dwarflocationlists. Because of the issues described above, setting the
flag may not make the debugging experience much better, and may actually
make it worse in cases where the variable actually is on the stack and
the more complicated analysis doesn't realize it.

A number of changes are included:
- Add a new pseudo-instruction, RegKill, which indicates that the value
in the register has been clobbered.
- Adjust regalloc to emit RegKills in the right places. Significantly,
this means that phis are mixed with StoreReg and RegKills after
regalloc.
- Track variable decomposition in ssa.LocalSlots.
- After the SSA backend is done, analyze the result and build location
lists for each LocalSlot.
- After assembly is done, update the location lists with the assembled
PC offsets, recompose variables, and build DWARF location lists. Emit the
list as a new linker symbol, one per function.
- In the linker, aggregate the location lists into a .debug_loc section.

TODO:
- currently disabled for non-X86/AMD64 because there are no data tables.

go build -toolexec 'toolstash -cmp' -a std succeeds.

With -dwarflocationlists false:
before: f02812195637909ff675782c0b46836a8ff01976
after:  06f61e8112a42ac34fb80e0c818b3cdb84a5e7ec
benchstat -geomean  /tmp/220352263 /tmp/621364410
completed   15 of   15, estimated time remaining 0s (eta 3:52PM)
name        old time/op       new time/op       delta
Template          199ms ± 3%        198ms ± 2%     ~     (p=0.400 n=15+14)
Unicode          96.6ms ± 5%       96.4ms ± 5%     ~     (p=0.838 n=15+15)
GoTypes           653ms ± 2%        647ms ± 2%     ~     (p=0.102 n=15+14)
Flate             133ms ± 6%        129ms ± 3%   -2.62%  (p=0.041 n=15+15)
GoParser          164ms ± 5%        159ms ± 3%   -3.05%  (p=0.000 n=15+15)
Reflect           428ms ± 4%        422ms ± 3%     ~     (p=0.156 n=15+13)
Tar               123ms ±10%        124ms ± 8%     ~     (p=0.461 n=15+15)
XML               228ms ± 3%        224ms ± 3%   -1.57%  (p=0.045 n=15+15)
[Geo mean]        206ms             377ms       +82.86%

name        old user-time/op  new user-time/op  delta
Template          292ms ±10%        301ms ±12%     ~     (p=0.189 n=15+15)
Unicode           166ms ±37%        158ms ±14%     ~     (p=0.418 n=15+14)
GoTypes           962ms ± 6%        963ms ± 7%     ~     (p=0.976 n=15+15)
Flate             207ms ±19%        200ms ±14%     ~     (p=0.345 n=14+15)
GoParser          246ms ±22%        240ms ±15%     ~     (p=0.587 n=15+15)
Reflect           611ms ±13%        587ms ±14%     ~     (p=0.085 n=15+13)
Tar               211ms ±12%        217ms ±14%     ~     (p=0.355 n=14+15)
XML               335ms ±15%        320ms ±18%     ~     (p=0.169 n=15+15)
[Geo mean]        317ms             583ms       +83.72%

name        old alloc/op      new alloc/op      delta
Template         40.2MB ± 0%       40.2MB ± 0%   -0.15%  (p=0.000 n=14+15)
Unicode          29.2MB ± 0%       29.3MB ± 0%     ~     (p=0.624 n=15+15)
GoTypes           114MB ± 0%        114MB ± 0%   -0.15%  (p=0.000 n=15+14)
Flate            25.7MB ± 0%       25.6MB ± 0%   -0.18%  (p=0.000 n=13+15)
GoParser         32.2MB ± 0%       32.2MB ± 0%   -0.14%  (p=0.003 n=15+15)
Reflect          77.8MB ± 0%       77.9MB ± 0%     ~     (p=0.061 n=15+15)
Tar              27.1MB ± 0%       27.0MB ± 0%   -0.11%  (p=0.029 n=15+15)
XML              42.7MB ± 0%       42.5MB ± 0%   -0.29%  (p=0.000 n=15+15)
[Geo mean]       42.1MB            75.0MB       +78.05%

name        old allocs/op     new allocs/op     delta
Template           402k ± 1%         398k ± 0%   -0.91%  (p=0.000 n=15+15)
Unicode            344k ± 1%         344k ± 0%     ~     (p=0.715 n=15+14)
GoTypes           1.18M ± 0%        1.17M ± 0%   -0.91%  (p=0.000 n=15+14)
Flate              243k ± 0%         240k ± 1%   -1.05%  (p=0.000 n=13+15)
GoParser           327k ± 1%         324k ± 1%   -0.96%  (p=0.000 n=15+15)
Reflect            984k ± 1%         982k ± 0%     ~     (p=0.050 n=15+15)
Tar                261k ± 1%         259k ± 1%   -0.77%  (p=0.000 n=15+15)
XML                411k ± 0%         404k ± 1%   -1.55%  (p=0.000 n=15+15)
[Geo mean]         439k              755k       +72.01%

name        old text-bytes    new text-bytes    delta
HelloSize         694kB ± 0%        694kB ± 0%   -0.00%  (p=0.000 n=15+15)

name        old data-bytes    new data-bytes    delta
HelloSize        5.55kB ± 0%       5.55kB ± 0%     ~     (all equal)

name        old bss-bytes     new bss-bytes     delta
HelloSize         133kB ± 0%        133kB ± 0%     ~     (all equal)

name        old exe-bytes     new exe-bytes     delta
HelloSize        1.04MB ± 0%       1.04MB ± 0%     ~     (all equal)

Change-Id: I991fc553ef175db46bb23b2128317bbd48de70d8
Reviewed-on: https://go-review.googlesource.com/41770
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-07-27 20:19:44 +00:00
Heschi Kreinick
59fe2fbfe5 [dev.debug] cmd/link: let the linker combine .debug_ranges, remove globals
The linker is pretty good at combining a bunch of symbols into a
section, so let it do .debug_ranges the normal way. Along the way,
remove a bunch of globals that were only used by one function that would
only be called once per invocation.

Change-Id: I1a528a438b193c41e7c444e8830516b07f11affc
Reviewed-on: https://go-review.googlesource.com/43890
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-07-26 18:39:50 +00:00
Ian Lance Taylor
6bb88fc280 cmd/link: use full link, not compile, to test for -no-?pie
This avoids an error from clang when using -nopie during compilation,
and permits us to check that the entire build succeeds.

Updates #21042

Change-Id: I2e6c7d5c97a85c223ed3288622bbb58ce33b8774
Reviewed-on: https://go-review.googlesource.com/50874
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-07-24 17:50:57 +00:00
Ian Lance Taylor
9e859d5e9c cmd/go, cmd/link: if -no-pie doesn't work, try -nopie
GCC says -no-pie, clang says -nopie.

Fixes #21042

Change-Id: Iadc83ea7a48ea0debc5064c1ee8da4ebff752044
Reviewed-on: https://go-review.googlesource.com/49710
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-07-20 18:52:06 +00:00
Austin Clements
c2c07c7989 runtime: always use 2MB stacks on 64-bit Windows
Currently, Windows stacks are either 128kB or 2MB depending on whether
the binary uses cgo. This is because we assume that Go system stacks
and the small amount of C code invoked by the standard library can
operate within smaller stacks, but general Windows C code assumes
larger stacks.

However, it's easy to call into arbitrary C code using the syscall
package on Windows without ever importing cgo into a binary. Such
binaries need larger system stacks even though they don't use cgo.

Fix this on 64-bit by increasing the system stack size to 2MB always.
This only costs address space, which is free enough on 64-bit to not
worry about. We keep (for now) the existing heuristic on 32-bit, where
address space comes at more of a premium.

Updates #20975.

Change-Id: Iaaaa9a2fcbadc825cddc797aaaea8d34ef8debf2
Reviewed-on: https://go-review.googlesource.com/49331
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2017-07-18 14:35:35 +00:00
Michael Pratt
123fd4640a cmd/link: skip R_ADDR relocs in .rela.plt for internal PIE
ld.addpltsym adds an R_X86_64_JMP_SLOT dynamic relocation to .rela.plt
and uses Addaddrplus to reference the GOT in Elf64_Rela.r_offset.

Addaddrplus results in an R_ADDR relocation, which here we transform
into an R_X86_64_64 dynamic relocation. This is wrong for several
reasons:

1. .rela.plt is not a writable, relro section. It is mapped read-only,
   causing the dynamic linker to segfault when it tried to handle the
   relocation. This was the immediate cause of internal PIE cgo
   crashes.

2. Relocations targetting other reloc sections are, as far as I can
   tell, undefined behavior in the ELF spec and are unlikely to be a
   good idea.

3. Even if the relocation did work, it isn't what we want. The
   relocation, if successfully handled, would have put an absolute
   address as the JMP_SLOT offset, but it should be the offset from the
   beginning of the binary, just like any other relocation. What we want
   is a statically resolved R_ADDR relocation, just as is used below for
   the R_X86_64_64 relocation.

Skipping the .rela.plt allows reloc() to handle these R_ADDR
relocations.

With this CL, internal PIE cgo binaries work.

Updates #18968

Change-Id: Ie74e6fe249e88150baa0e340b1cb128cf7f28673
Reviewed-on: https://go-review.googlesource.com/47837
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-07-09 19:23:41 +00:00
Lynn Boger
738739f565 cmd/link: implement trampolines for ppc64le with ext linking
When using golang on ppc64le there have been issues
when building executables that generate extremely large text
sections.  This is due to the call instruction and the limitation
on the offset field, which is smaller than most platforms.  If the
size of the call target offset is too big for the offset field in
the call instruction, then link errors can occur.

The original solution to this problem in golang was to split the
text section when it became too large, allowing the external (GNU)
linker to insert the necessary stub to handle the long call.  That
worked fine until the another size limit for the program size was hit,
where a plt_branch was created instead of a long branch.  In that case
the plt_branch code sequence expects r2 to contain the address of the
TOC, but when golang creates dynamic executables by default
(-buildmode=exe) r2 does not always contain the address of the TOC
and as a result when building programs that reach this extremely
large size, a runtime SEGV or SIGILL can occur due to branching to a bad
address.

When using internal linking, trampolines are generated to handle the
long calls but the text sections are not split.  With this change,
text sections will still be split approrpriately with external linking
but if the buildmode being used does not maintain r2 as the TOC
addresses, then trampolines will be created for those calls.

Fixes #20497

Change-Id: If5400b0f86c2c08e106b332be6db0b259b07d93d
Reviewed-on: https://go-review.googlesource.com/45130
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-06-14 14:12:11 +00:00
Russ Cox
4f2269edbd cmd/link: add -importcfg to specify import resolution
Adds the ability to specify the file location of each imported package,
like in the -importcfg added to cmd/compile in a related CL.
In effect, -importcfg is a generalization of and supersedes -installsuffix
and -L. Of course, those flags will continue to be supported, for
compatibility with other tools.

Having this flag in Go 1.9 will let us try some experiments involving
package management without needing guinea pigs to build a custom
Go toolchain.

This flag also helps with #14271 at some later point.

For #20579.

Change-Id: Ie4c171bcd3aa2faa446ac340e36516f2f9853882
Reviewed-on: https://go-review.googlesource.com/44851
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-06-06 19:49:58 +00:00
Russ Cox
51711d1429 cmd/link: fix accidentally-quadratic library loading
Programs built from N libraries required O(N²) time to do the
deduplication checks, even if there were never any duplicates.
In most programs N is small enough not to worry, but this may
affect large programs.

Noticed by inspection, not any specific bug report.

Fixes #20578.

Change-Id: Ic4108f1058be39da990a79b1e0b8ce95fde44cef
Reviewed-on: https://go-review.googlesource.com/44852
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-06-05 19:56:34 +00:00
Dmitry Savintsev
4c86f7bd49 cmd/link: fix left-over reference to reflect.c
Replaced ../gc/reflect.c with
cmd/compile/internal/gc/reflect.go.

Fixes #20525

Change-Id: Ibafd36ea446ace5c677df27873a4bbf716a0a9bc
Reviewed-on: https://go-review.googlesource.com/44376
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-05-30 01:10:56 +00:00
Heschi Kreinick
b74f01d76f cmd/internal/dwarf: update to DWARF4, emit frame_base
In preparation for CL 41770, upgrade .debug_info to DWARF4, and emit
DW_AT_frame_base on subprograms. This should make no semantic
difference.

Also fix a long-standing bug/inconsistency in puttattr: it didn't
add the addend to ref_addrs. Previously this didn't matter because it
was only used for types, but now it's used for section offsets into
symbols that have multiple entries.

RELNOTE=yes

Change-Id: Ib10654ac92edfa29c5167c44133648151d70cf76
Reviewed-on: https://go-review.googlesource.com/44210
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2017-05-26 21:29:21 +00:00
Alessandro Arzilli
2ad41a3090 cmd/compile: output DWARF lexical blocks for local variables
Change compiler and linker to emit DWARF lexical blocks in .debug_info
section when compiling with -N -l.

Version of debug_info is updated from DWARF v2 to DWARF v3 since
version 2 does not allow lexical blocks with discontinuous PC ranges.

Remaining open problems:
- scope information is removed from inlined functions
- variables records do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, even before its declaration.

Updates #6913.
Updates #12899.

Change-Id: Idc6808788512ea20e7e45bcf782453acb416fb49
Reviewed-on: https://go-review.googlesource.com/40095
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-05-18 23:10:50 +00:00
Alex Brainman
b5e964cc1c cmd/link: make sure that runtime.epclntab lives in .text section
Second attempt to fix #14710.

CL 35272 already tried to fix this issue. But CL 35272 assumed
that runtime.epclntab type is STEXT, while it is actually SRODATA.

This CL uses Symbol.Sect.Seg to determine if symbol is part
of Segtext or Segdata.

Fixes #14710

Change-Id: Ic6b6f657555c87a64d2bc36cc4c07ab0591d00c4
Reviewed-on: https://go-review.googlesource.com/42390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-05-18 05:32:41 +00:00
Alex Brainman
1d44c4e378 cmd/link: actually generate .debug_gdb_scripts section on windows
Adjust finddebugruntimepath to look for runtime/debug.go file
instead of runtime/runtime.go. This actually finds runtime.GOMAXPROCS
in every Go executable (including windows).

I also included "-Wl,-T,fix_debug_gdb_scripts.ld" parameter to gcc
invocation on windows to work around gcc bug (see #20183 for details).

This CL only fixes windows -buildmode=exe, buildmode=c-archive
is still broken.

Thanks to Egon Elbre and Nick Clifton for investigation.

Fixes #20183
Fixes #20218

Change-Id: I5369a4db3913226aef3d9bd6317446856b0a1c34
Reviewed-on: https://go-review.googlesource.com/43331
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-05-15 06:16:19 +00:00
Josh Bleecher Snyder
201fd16568 cmd/link: set Fieldtrack symbol type to SDATA
Fixes #20316

Change-Id: I2553ad9a82dfcb30f020c2a3e37b868111425a20
Reviewed-on: https://go-review.googlesource.com/43151
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-05-10 19:24:29 +00:00
David Chase
41d0bbdc16 cmd/link: include DW_AT_producer in .debug_info
This can make life easier for Delve (and other debuggers),
and can help them with bug reports.

Sample producer field (from objdump):
<48> DW_AT_producer : Go cmd/compile devel +8a59dbf41a Mon May 8 16:02:44 2017 -0400

Change-Id: I0605843c959b53a60a25a3b870aa8755bf5d5b13
Reviewed-on: https://go-review.googlesource.com/33588
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-05-10 14:47:41 +00:00
Ian Lance Taylor
5331e7e9df cmd/internal/obj, cmd/link: fix st_other field on PPC64
In PPC64 ELF files, the st_other field indicates the number of
prologue instructions between the global and local entry points.
We add the instructions in the compiler and assembler if -shared is used.
We were assuming that the instructions were present when building a
c-archive or PIE or doing dynamic linking, on the assumption that those
are the cases where the go tool would be building with -shared.
That assumption fails when using some other tool, such as Bazel,
that does not necessarily use -shared in exactly the same way.

This CL records in the object file whether a symbol was compiled
with -shared (this will be the same for all symbols in a given compilation)
and uses that information when setting the st_other field.

Fixes #20290.

Change-Id: Ib2b77e16aef38824871102e3c244fcf04a86c6ea
Reviewed-on: https://go-review.googlesource.com/43051
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-05-09 23:36:51 +00:00
Elias Naur
45d42fdcea cmd/link/internal/ld: don't link with -no_pie on darwin/arm64
Ever since CL 33301 linking darwin/arm64 excutables has resulted in
warnings like:

ld: warning: -no_pie ignored for arm64

Remove -no_pie on darwin/arm64.

Change-Id: I9f7685351fa8cce29795283e1a24fc7a6753d698
Reviewed-on: https://go-review.googlesource.com/42815
Run-TryBot: Elias Naur <elias.naur@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-07 19:12:26 +00:00
Kevin Burke
9058b9ae49 os, cmd/link: fix typos
Also switch "stating" to "statting" to describe applying os.Stat to
a resource; the former is more confusable than the latter.

Change-Id: I9d8e3506bd383f8f1479c05948c03b8c633dc4af
Reviewed-on: https://go-review.googlesource.com/42855
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-05-07 18:13:02 +00:00
Egon Elbre
e94b9d4143 cmd/link/internal/ld: fix external linking on windows
gcc on windows writes invalid location for .debug_gdb_scripts
which causes the executable loading to fail.

Fixes #20183

Change-Id: I5134013bc926b44a55b528f66ab79555855d1f4d
Reviewed-on: https://go-review.googlesource.com/42651
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-06 06:11:31 +00:00
Carlos Eduardo Seo
09b71d563a cmd/internal/obj/ppc64, cmd/link/internal/ppc64: Change function alignment to 16
The Power processor manual states that "Branches not from the last instruction
of an aligned quadword and not to the first instruction of an aligned quadword
cause inefficiencies in the IBuffer". This changes the function alignment from 8
to 16 bytes to comply with that.

Fixes #18963

Change-Id: Ibce9bf8302110a86c6ab05948569af9ffdfcf4bb
Reviewed-on: https://go-review.googlesource.com/36390
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
2017-05-05 19:03:05 +00:00
David Crawshaw
27a10f7da7 cmd/link: stop passing unused read_only_relocs
The external darwin linker has been printing:

	ld: warning: -read_only_relocs cannot be used with x86_64

for a long time. Now that it is printed by CL 33301, we may as
well get rid of it.

Fixes #20246

Change-Id: I1147cf1ff197fdfda228a1349f13627bcf9fc72f
Reviewed-on: https://go-review.googlesource.com/42730
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-05-05 11:35:58 +00:00
Alex Brainman
507f4d5f48 cmd/link: do not read .bss sections in ldpe
For .bss section symbol ldelf does not set P (raw symbol data).
Make ldpe do the same.

Change-Id: Ib3d558456f505ee568d0972465fa9b08b5794a87
Reviewed-on: https://go-review.googlesource.com/42631
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-05 01:00:11 +00:00
Ian Lance Taylor
39c07ce9e5 cmd/link: set ELF CPIC bit in mips64 objects
We already set it for mips32 objects. The native ELF linker warns when
linking PIC objects with non-PIC objects. Our objects are PIC, but we
were not marking them as such.

Fixes #20243.

Change-Id: Ifab131200b263e4c72cf81f7b131a65ac02a13a9
Reviewed-on: https://go-review.googlesource.com/42710
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-04 20:35:56 +00:00
Shenghou Ma
4d7a5edb7e cmd/link/internal/ld: always show output from external linker
Fixes #17935.

Change-Id: I49b0f6cee29ea76ed62b8faa5d6d1f51be41bf84
Reviewed-on: https://go-review.googlesource.com/33301
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-05-03 15:01:06 +00:00
Josh Bleecher Snyder
18fb670e5e cmd/internal/obj: fix LSym.Type during compilation, not linking
Prior to this CL, the compiler and assembler
were sloppy about the LSym.Type for LSyms
containing static data.

The linker then fixed this up, converting
Sxxx and SBSS to SDATA, and SNOPTRBSS to SNOPTRDATA
if it noticed that the symbol had associated data.

It is preferable to just get this right in cmd/compile
and cmd/asm, because it removes an unnecessary traversal
of the symbol table from the linker (see #14624).
Do this by touching up the LSym.Type fixes in
LSym.prepwrite and Link.Globl.

I have confirmed by instrumenting the linker
that the now-eliminated code paths were unreached.
And an additional check in the object file writing code
will help preserve that invariant.

There was a case in the Windows linker,
with internal linking and cgo,
where we were generating SNOPTRBSS symbols with data.
For now, convert those at the site at which they occur
into SNOPTRDATA, just like they were.

Does not pass toolstash-check,
but does generate identical linked binaries.

No compiler performance changes.

Change-Id: I77b071ab103685ff8e042cee9abb864385488872
Reviewed-on: https://go-review.googlesource.com/40864
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2017-05-02 00:21:33 +00:00
Michael Hudson-Doyle
164f99e584 Revert "cmd/link: replace SHIDDEN bit in SymKind with a bit of Attribute"
This reverts commit a69222d949.

Reason for revert: broke ppc64le

Change-Id: I57d275177e90f036caf7dbade9669b8121dfa437
Reviewed-on: https://go-review.googlesource.com/42194
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2017-05-01 00:56:40 +00:00
Michael Hudson-Doyle
a69222d949 cmd/link: replace SHIDDEN bit in SymKind with a bit of Attribute
Change-Id: I02dab81393cc9339895f0076df41a652aded5b60
Reviewed-on: https://go-review.googlesource.com/42025
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-30 23:28:47 +00:00
Michael Hudson-Doyle
3bcb481aa3 cmd/link: rename AttrHidden to AttrNotInSymbolTable
I want to move the SHIDDEN type bit into Attribute, but AttrHidden is already
there and means something completely different, so rename it. (I'll give the
SHIDDEN bit a better name when it moves too).

Change-Id: I075403d9542b7626d4c1f6db9094329c4181aad3
Reviewed-on: https://go-review.googlesource.com/42024
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-30 23:28:29 +00:00
Michael Hudson-Doyle
f72534ab6a cmd/link: document the various Attribute values
Change-Id: I11c14111b6c72eab5fc11e9e28cd8b37ad99b401
Reviewed-on: https://go-review.googlesource.com/42019
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-30 23:27:46 +00:00
Michael Hudson-Doyle
e29ea14100 cmd/link/internal/ld: unexport ReadOnly and RelROMap
Change-Id: I08e33b92dd8a22e28ec15aa5753904aa8e1c71f5
Reviewed-on: https://go-review.googlesource.com/42031
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-28 20:02:50 +00:00
Michael Hudson-Doyle
4aca8b00ff cmd/internal/objabi: shrink SymType down to a uint8
Now that it only takes small values.

Change-Id: I08086d392529d8775b470d65afc2475f8d0e7f4a
Reviewed-on: https://go-review.googlesource.com/42030
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-28 20:02:20 +00:00
Michael Hudson-Doyle
d2a9545178 cmd/internal: remove SymKind values that are only checked for, never set
Change-Id: Id152767c033c12966e9e12ae303b99f38776f919
Reviewed-on: https://go-review.googlesource.com/40987
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-28 20:01:54 +00:00
Michael Hudson-Doyle
be2ee2a4b4 cmd/internal/objabi, cmd/link: move linker-only symkind values into linker
Many (most!) of the values of objapi.SymKind are used only in the linker, so
this creates a separate cmd/link/internal/ld.SymKind type, removes most values
from SymKind and maps one to the other when reading object files in the linker.

Two of the remaining objapi.SymKind values are only checked for, never set and
so will never be actually found but I wanted to keep this to the most
mechanical change possible.

Change-Id: I4bbc5aed6713cab3e8de732e6e288eb77be0474c
Reviewed-on: https://go-review.googlesource.com/40985
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-27 21:56:12 +00:00
Hana Kim
b1868cf107 dwarf: add marker for embedded fields in dwarf
Currently, the following two codes generate the identical dwarf info
for type Foo.

prog 1)
type Foo struct {
   Bar
}

prog 2)
type Foo struct {
   Bar Bar
}

This change adds a go-specific attribute DW_AT_go_embedded_field
to annotate each member entry. Its absence or false value indicates
the corresponding member is not an embedded field.

Update #20037

Change-Id: Ibcbd2714f3e4d97c7b523d7398f29ab2301cc897
Reviewed-on: https://go-review.googlesource.com/41873
Reviewed-by: David Chase <drchase@google.com>
2017-04-27 19:57:02 +00:00
Matthew Dempsky
06e5749f01 cmd/link: cleanup after IntSize->PtrSize conversion
Passes toolstash-check -all.

Updates #19954.

Change-Id: Ic162306eed105912491bf1df47e32c32653f824c
Reviewed-on: https://go-review.googlesource.com/41490
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-23 02:07:16 +00:00
Matthew Dempsky
c87520c598 cmd: remove IntSize and Widthint
Use PtrSize and Widthptr instead. CL prepared mostly with sed and
uniq.

Passes toolstash-check -all.

Fixes #19954.

Change-Id: I09371bd7128672885cb8bc4e7f534ad56a88d755
Reviewed-on: https://go-review.googlesource.com/40506
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-22 17:43:43 +00:00
Dave Cheney
d728be70f4 cmd/link/internal/ld: remove C style gotos from ldelf
ld.ldelf contained a mixture of normal and C style, goto bad, error
handling. The use of goto requires many variables to be declared well
before their use which inhibited further refactoring to this method.

This CL removes the gotos in this function. Future CLs will address
remainder of the C style function scoped declarations in this function.

Change-Id: Ib9def495209a2f8deb11dcf30ee954bca95390c6
Reviewed-on: https://go-review.googlesource.com/41172
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-20 01:37:08 +00:00
Todd Neal
dc444418d9 cmd/internal: remove duplicate pathToPrefix function
goobj.importPathToPrefix is 3x faster than gc.pathToPrefix so rename and
move it to cmd/internal/objabi which is already imported by both goobj and
gc.

Change-Id: I10eda5bce95ef6d5d888818c5c47258c2833ea45
Reviewed-on: https://go-review.googlesource.com/40875
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-19 11:47:45 +00:00
Matthew Dempsky
1e3570ac86 cmd/internal/objabi: extract shared functionality from obj
Now only cmd/asm and cmd/compile depend on cmd/internal/obj. Changing
the assembler backends no longer requires reinstalling cmd/link or
cmd/addr2line.

There's also now one canonical definition of the object file format in
cmd/internal/objabi/doc.go, with a warning to update all three
implementations.

objabi is still something of a grab bag of unrelated code (e.g., flag
and environment variable handling probably belong in a separate "tool"
package), but this is still progress.

Fixes #15165.
Fixes #20026.

Change-Id: Ic4b92fac7d0d35438e0d20c9579aad4085c5534c
Reviewed-on: https://go-review.googlesource.com/40972
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-19 00:00:09 +00:00
Michael Hudson-Doyle
743fe0697d cmd/link: replace Segment's linked list of Sections with a slice
Just noticed this in passing.

Change-Id: I58fa828ef58598209ed4cbe4abc6f9f02ffc4844
Reviewed-on: https://go-review.googlesource.com/40896
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-18 21:24:32 +00:00
Josh Bleecher Snyder
da15fe6870 cmd/internal/obj: rework gclocals handling
The compiler handled gcargs and gclocals LSyms unusually.
It generated placeholder symbols (makefuncdatasym),
filled them in, and then renamed them for content-addressability.
This is an important binary size optimization;
the same locals information occurs over and over.

This CL continues to treat these LSyms unusually,
but in a slightly more explicit way,
and importantly for concurrent compilation,
in a way that does not require concurrent
modification of Ctxt.Hash.

Instead of creating gcargs and gclocals in the usual way,
by creating a types.Sym and then an obj.LSym,
we add them directly to obj.FuncInfo,
initialize them in obj.InitTextSym,
and deduplicate and add them to ctxt.Data at the end.
Then the backend's job is simply to fill them in
and rename them appropriately.

Updates #15756

name       old alloc/op      new alloc/op      delta
Template        38.8MB ± 0%       38.7MB ± 0%  -0.22%  (p=0.016 n=5+5)
Unicode         29.8MB ± 0%       29.8MB ± 0%    ~     (p=0.690 n=5+5)
GoTypes          113MB ± 0%        113MB ± 0%  -0.24%  (p=0.008 n=5+5)
SSA             1.25GB ± 0%       1.24GB ± 0%  -0.39%  (p=0.008 n=5+5)
Flate           25.3MB ± 0%       25.2MB ± 0%  -0.43%  (p=0.008 n=5+5)
GoParser        31.7MB ± 0%       31.7MB ± 0%  -0.22%  (p=0.008 n=5+5)
Reflect         78.2MB ± 0%       77.6MB ± 0%  -0.80%  (p=0.008 n=5+5)
Tar             26.6MB ± 0%       26.3MB ± 0%  -0.85%  (p=0.008 n=5+5)
XML             42.4MB ± 0%       41.9MB ± 0%  -1.04%  (p=0.008 n=5+5)

name       old allocs/op     new allocs/op     delta
Template          378k ± 0%         377k ± 1%    ~     (p=0.151 n=5+5)
Unicode           321k ± 1%         321k ± 0%    ~     (p=0.841 n=5+5)
GoTypes          1.14M ± 0%        1.14M ± 0%  -0.47%  (p=0.016 n=5+5)
SSA              9.71M ± 0%        9.67M ± 0%  -0.33%  (p=0.008 n=5+5)
Flate             233k ± 1%         232k ± 1%    ~     (p=0.151 n=5+5)
GoParser          316k ± 0%         315k ± 0%  -0.49%  (p=0.016 n=5+5)
Reflect           979k ± 0%         972k ± 0%  -0.75%  (p=0.008 n=5+5)
Tar               250k ± 0%         247k ± 1%  -0.92%  (p=0.008 n=5+5)
XML               392k ± 1%         389k ± 0%  -0.67%  (p=0.008 n=5+5)

Change-Id: Idc36186ca9d2f8214b5f7720bbc27b6bb22fdc48
Reviewed-on: https://go-review.googlesource.com/40697
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-18 02:13:32 +00:00
Michael Hudson-Doyle
533ed967c6 cmd/link: only include the version info and export data in ABI hash
Previously the "ABI hash" for a package (used to determine if a loaded shared
library has the ABI expected by its loader) was the hash of the entire
__.PKGDEF file. But that means it depends on the build ID generated by the go
tool for the package, which means that if a file is added (even a .c or .h
file!) to the package, the ABI changes, perhaps uncessarily.

Fixes #19920

Change-Id: If919481e1a03afb350c8a9c7a0666bb90ee90270
Reviewed-on: https://go-review.googlesource.com/40401
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-17 22:02:01 +00:00
David du Colombier
746441f97f cmd/link: skip TestRuntimeTypeDIEs on Plan 9
TestRuntimeTypeDIEs has been added in CL 38350. This
test is failing on Plan 9 because executables don't
have a DWARF symbol table.

Fixes #19944.

Change-Id: I121875bfd5f9f02ed668f8fb0686a0edffa2a99d
Reviewed-on: https://go-review.googlesource.com/40452
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-12 18:16:41 +00:00
Alessandro Arzilli
073247f11f cmd/link: export specialized variants of runtime._type to debug_info
The reflect package can be used to create new types at runtime, these
types will have runtime._type entries describing them but no entry in
debug_info (obviously).

A debugger that wanted to print the value of variables with such types
will have to read the runtime._type directly, however the
"specializations" of runtime._type (runtime.slicetype, runtime.maptype,
etc) are not exported to debug_info, besides runtime.interfacetype.

All those types (i.e. runtime.slicetype, runtime.maptype, etc) should
be exported to debug_info so that debuggers don't have to hard-code
their description.

Fixes #19602

Change-Id: I086d523a4421a4ed964e16bc3c2274319a98b45b
Reviewed-on: https://go-review.googlesource.com/38350
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2017-04-12 13:25:45 +00:00
Joel Sing
9417c022c6 cmd/link,runtime/cgo: enable PT_TLS generation on OpenBSD
OpenBSD 6.0 and later have support for PT_TLS in ld.so(1). Now that OpenBSD
6.1 has been released, OpenBSD 5.9 is no longer officially supported and Go
can start generating PT_TLS for OpenBSD cgo binaries. This also allows us
to remove the workarounds in the OpenBSD cgo runtime.

This change also removes the environ and progname exports - these are now
provided directly by ld.so(1) itself.

Fixes #19932

Change-Id: I42e75ef9feb5dcd4696add5233497e3cbc48ad52
Reviewed-on: https://go-review.googlesource.com/40331
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-11 16:33:16 +00:00
Josh Bleecher Snyder
3cf1ce40bd Revert "cmd/compile: output DWARF lexical blocks for local variables"
This reverts commit c8b889cc48.

Reason for revert: broke noopt build, compiler performance regression, new Curfn uses

Let's fix those and then try this again.

Change-Id: Icc3cad1365d04cac8fd09da9dbb0bbf55c13ef44
Reviewed-on: https://go-review.googlesource.com/39991
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 19:52:26 +00:00
Alessandro Arzilli
c8b889cc48 cmd/compile: output DWARF lexical blocks for local variables
Change compiler and linker to emit DWARF lexical blocks in debug_info.
Version of debug_info is updated from DWARF v.2 to DWARF v.3 since version 2
does not allow lexical blocks with discontinuous ranges.

Second attempt at https://go-review.googlesource.com/#/c/29591/

Remaining open problems:
- scope information is removed from inlined functions
- variables in debug_info do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, before its declaration.

Updates golang/go#12899, golang/go#6913

Change-Id: I0e260a45b564d14a87b88974eb16c5387cb410a5
Reviewed-on: https://go-review.googlesource.com/36879
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-07 18:15:06 +00:00
Cherry Zhang
a1cedf0842 cmd/link: canonicalize the "package" of dupok text symbols
Dupok symbols may be defined in multiple packages. Its associated
package is chosen sort of arbitrarily (the first containing package
that the linker loads). Canonicalize its package to the package
with which it will be laid down in text, which is the first package
in dependency order that defines the symbol. So later passes (for
example, trampoline insertion pass) know that the dupok symbol
is laid down along with the package.

Fixes #19764.

Change-Id: I7cbc7474ff3016d5069c8b7be04af934abab8bc3
Reviewed-on: https://go-review.googlesource.com/39150
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: David Chase <drchase@google.com>
2017-04-02 03:25:02 +00:00
Alex Brainman
361af94d5d cmd/internal/obj, cmd/link: remove Hwindowsgui everywhere
Hwindowsgui has the same meaning as Hwindows - build PE
executable. So use Hwindows everywhere.

Change-Id: I2cae5777f17c7bc3a043dfcd014c1620cc35fc20
Reviewed-on: https://go-review.googlesource.com/38761
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-30 22:51:43 +00:00
Alex Brainman
4e3a1e409a cmd/link/internal/ld: introduce and use windowsgui variable
cmd/link -H flag is stored in variable of type
cmd/internal/obj.HeadType. The HeadType type from cmd/internal/obj
accepts Hwindows and Hwindowsgui values, but these values have
same meaning - build PE executable, except for 2 places in
cmd/link/internal/ld package.

This CL introduces code to store cmd/link "windowsgui" -H flag
in cmd/link/internal/ld, so cmd/internal/obj.Hwindowsgui can be
removed in the next CL.

This CL also includes 2 changes to code where distinction
between Hwindows and Hwindowsgui is important.

Change-Id: Ie5ee1f374e50c834652a037f2770118d56c21a2a
Reviewed-on: https://go-review.googlesource.com/38760
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-30 22:51:19 +00:00
Josh Bleecher Snyder
94c62efe9c cmd/link: skip TestDWARF when cgo is disabled
While we're here, fix a Skip/Skipf error I noticed.

Fixes #19796.

Change-Id: I59b1f5b5ea727fc314acfee8445b3de0b5af1e46
Reviewed-on: https://go-review.googlesource.com/38992
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-30 22:32:33 +00:00
David du Colombier
ed6f2978a2 cmd/link: skip TestDWARF on Plan 9
TestDWARF has been added in CL 38855. This test is
failing on Plan 9 because executables don't have
a DWARF symbol table.

Fixes #19793.

Change-Id: I7fc547a7c877b58cc4ff6b4eb5b14852e8b4668b
Reviewed-on: https://go-review.googlesource.com/38931
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-30 20:24:19 +00:00
Russ Cox
18e77673d8 cmd/link: emit a mach-o dwarf segment that dsymutil will accept
Right now, at least with Xcode 8.3, we invoke dsymutil and dutifully
copy what it produces back into the binary, but it has actually dropped
all the DWARF information that we wanted, because it didn't like
the look of go.o.

Make it like the look of go.o.

DWARF is tested in other ways, but typically indirectly and not for cgo programs.
Add a direct test, and one that exercises cgo.
This detects missing dwarf information in cgo-using binaries on macOS,
at least with Xcode 8.3, and possibly earlier versions as well.

Fixes #19772.

Change-Id: I0082e52c0bc8fc4e289770ec3dc02f39fd61e743
Reviewed-on: https://go-review.googlesource.com/38855
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-03-30 17:31:50 +00:00
Russ Cox
b28f2f7399 cmd/link: make mach-o dwarf segment properly aligned
Without this, the load fails during kernel exec, which results in the
mysterious and completely uninformative "Killed: 9" error.

It appears that the stars (or at least the inputs) were properly aligned
with earlier versions of Xcode so that this happened accidentally.
Make it happen on purpose.

Gregory Man bisected the breakage to this change in LLVM,
which fits the theory nicely:
https://github.com/llvm-mirror/llvm/commit/9a41e59c

Fixes #19734.

Change-Id: Ice67a09af2de29d3c0d5e3fcde6a769580897c95
Reviewed-on: https://go-review.googlesource.com/38854
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-03-30 12:29:18 +00:00
Russ Cox
23dc3633ca cmd/link: disable mach-o dwarf munging with -w (in addition to -s)
Might as well provide a way around the mach-o munging
that doesn't require stripping all symbols.
After all, -w does mean no DWARF.

For #11887, #19734, and anyone else that needs to disable
this code path without losing the symbol table.

Change-Id: I254b7539f97fb9211fa90f446264b383e7f3980f
Reviewed-on: https://go-review.googlesource.com/38853
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-03-30 12:28:11 +00:00
Russ Cox
371c83b594 cmd/link: do not pass -s through to host linker on macOS
This keeps the host linker from printing
ld: warning: option -s is obsolete and being ignored

Fixes #19775.

Change-Id: I18dd4e4b3f59cbf35dad770fd65e6baea5a7347f
Reviewed-on: https://go-review.googlesource.com/38851
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-30 02:45:45 +00:00
Cherry Zhang
15b37655bc cmd/link: on PPC64, put plt stubs at beginning of Textp
Put call stubs at the beginning (instead of the end). So the
trampoline pass knows the addresses of the stubs, and it can
insert trampolines when necessary.

Fixes #19425.

Change-Id: I1e06529ef837a6130df58917315610d45a6819ca
Reviewed-on: https://go-review.googlesource.com/38131
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
2017-03-15 16:19:27 +00:00
Matthew Dempsky
d343478295 cmd/link: eliminate markextra
This appears to be leftover from when instruction selection happened
in the linker. Many of the morestackX functions listed don't even
exist anymore.

Now that we select instructions within the compiler and assembler,
normal deadcode elimination mechanisms should suffice for these
symbols.

Change-Id: I2cb1e435101392e7c983957c4acfbbcc87a5ca7d
Reviewed-on: https://go-review.googlesource.com/38077
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-12 11:05:10 +00:00
Alex Brainman
d3f5e36917 cmd/link: use IMAGE_SYM_CLASS_STATIC for local symbols
Sometimes asm code in 2 different packages name its global
symbols with the same name. When these symbols are passed
to gcc, it refuses to link them thinking they are duplicate.
Mark these symbols with IMAGE_SYM_CLASS_STATIC.

Fixes #19198.

Change-Id: Ia5f59ede47354a2b48ce60b7d406c9f097ff2000
Reviewed-on: https://go-review.googlesource.com/37810
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-07 03:26:47 +00:00
Matthew Dempsky
7c84dc79fd cmd/internal/obj, cmd/link: bump magic string to go19ld
golang.org/cl/37231 changed the object file format, but forgot to bump
the version string.

Change-Id: I8351ec8ed55e65479006e7c0df20254d0e31015f
Reviewed-on: https://go-review.googlesource.com/37798
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-06 19:13:57 +00:00
Josh Bleecher Snyder
57e038615d cmd/internal/src: cache prefixed filenames
CL 37234 introduced string concatenation into some hot code. 
This CL does that work earlier and caches the result.

Updates #19386

Performance impact vs master:

name       old time/op      new time/op      delta
Template        223ms ± 5%       216ms ± 5%   -2.98%  (p=0.001 n=20+20)
Unicode        98.7ms ± 4%      99.0ms ± 4%     ~     (p=0.749 n=20+19)
GoTypes         631ms ± 4%       626ms ± 4%     ~     (p=0.253 n=20+20)
Compiler        2.91s ± 1%       2.87s ± 3%   -1.11%  (p=0.005 n=18+20)
SSA             4.48s ± 2%       4.36s ± 2%   -2.77%  (p=0.000 n=20+20)
Flate           130ms ± 2%       129ms ± 6%     ~     (p=0.428 n=19+20)
GoParser        160ms ± 4%       157ms ± 3%   -1.62%  (p=0.005 n=20+18)
Reflect         395ms ± 2%       394ms ± 4%     ~     (p=0.445 n=20+20)
Tar             120ms ± 5%       118ms ± 6%     ~     (p=0.101 n=19+20)
XML             224ms ± 3%       223ms ± 3%     ~     (p=0.544 n=19+19)

name       old user-ns/op   new user-ns/op   delta
Template   291user-ms ± 5%  265user-ms ± 5%   -9.02%  (p=0.000 n=20+19)
Unicode    140user-ms ± 3%  139user-ms ± 8%     ~     (p=0.904 n=20+20)
GoTypes    844user-ms ± 3%  849user-ms ± 3%     ~     (p=0.251 n=20+18)
Compiler   4.06user-s ± 5%  3.98user-s ± 2%     ~     (p=0.056 n=20+20)
SSA        6.89user-s ± 5%  6.50user-s ± 3%   -5.61%  (p=0.000 n=20+20)
Flate      164user-ms ± 5%  163user-ms ± 4%     ~     (p=0.365 n=20+19)
GoParser   206user-ms ± 6%  204user-ms ± 4%     ~     (p=0.534 n=20+18)
Reflect    501user-ms ± 4%  505user-ms ± 5%     ~     (p=0.383 n=20+20)
Tar        151user-ms ± 3%  152user-ms ± 7%     ~     (p=0.798 n=17+20)
XML        283user-ms ± 7%  280user-ms ± 5%     ~     (p=0.301 n=20+20)

name       old alloc/op     new alloc/op     delta
Template       42.5MB ± 0%      40.2MB ± 0%   -5.59%  (p=0.000 n=20+20)
Unicode        31.7MB ± 0%      31.0MB ± 0%   -2.19%  (p=0.000 n=20+18)
GoTypes         124MB ± 0%       117MB ± 0%   -5.90%  (p=0.000 n=20+20)
Compiler        533MB ± 0%       490MB ± 0%   -8.07%  (p=0.000 n=20+20)
SSA             989MB ± 0%       893MB ± 0%   -9.74%  (p=0.000 n=20+20)
Flate          27.8MB ± 0%      26.1MB ± 0%   -5.92%  (p=0.000 n=20+20)
GoParser       34.3MB ± 0%      32.1MB ± 0%   -6.43%  (p=0.000 n=19+20)
Reflect        84.6MB ± 0%      81.4MB ± 0%   -3.84%  (p=0.000 n=20+20)
Tar            28.8MB ± 0%      27.7MB ± 0%   -3.89%  (p=0.000 n=20+20)
XML            47.2MB ± 0%      44.2MB ± 0%   -6.45%  (p=0.000 n=20+19)

name       old allocs/op    new allocs/op    delta
Template         420k ± 1%        381k ± 1%   -9.35%  (p=0.000 n=20+20)
Unicode          338k ± 1%        324k ± 1%   -4.29%  (p=0.000 n=20+19)
GoTypes         1.28M ± 0%       1.15M ± 0%  -10.30%  (p=0.000 n=20+20)
Compiler        5.06M ± 0%       4.41M ± 0%  -12.92%  (p=0.000 n=20+20)
SSA             9.14M ± 0%       7.91M ± 0%  -13.46%  (p=0.000 n=19+20)
Flate            267k ± 0%        241k ± 1%   -9.53%  (p=0.000 n=20+20)
GoParser         347k ± 1%        312k ± 0%  -10.15%  (p=0.000 n=19+20)
Reflect         1.07M ± 0%       1.00M ± 0%   -6.86%  (p=0.000 n=20+20)
Tar              274k ± 1%        256k ± 1%   -6.73%  (p=0.000 n=20+20)
XML              448k ± 0%        398k ± 0%  -11.17%  (p=0.000 n=20+18)


Performance impact when applied together with CL 37234
atop CL 37234's parent commit (i.e. as if it were
a part of CL 37234), to show that this commit
makes CL 37234 completely performance-neutral:

name       old time/op      new time/op      delta
Template        222ms ±14%       222ms ±14%    ~     (p=1.000 n=14+15)
Unicode         104ms ±18%       106ms ±18%    ~     (p=0.650 n=13+14)
GoTypes         653ms ± 7%       638ms ± 5%    ~     (p=0.145 n=14+12)
Compiler        3.10s ± 1%       3.13s ±10%    ~     (p=1.000 n=2+2)
SSA             4.73s ±11%       4.68s ±11%    ~     (p=0.567 n=15+15)
Flate           136ms ± 4%       133ms ± 7%    ~     (p=0.231 n=12+14)
GoParser        163ms ±11%       169ms ±10%    ~     (p=0.352 n=14+14)
Reflect         415ms ±15%       423ms ±20%    ~     (p=0.715 n=15+14)
Tar             133ms ±17%       130ms ±23%    ~     (p=0.252 n=14+15)
XML             236ms ±16%       235ms ±14%    ~     (p=0.874 n=14+14)

name       old user-ns/op   new user-ns/op   delta
Template   271user-ms ±10%  271user-ms ±10%    ~     (p=0.780 n=14+15)
Unicode    143user-ms ± 5%  146user-ms ±11%    ~     (p=0.432 n=12+14)
GoTypes    864user-ms ± 5%  866user-ms ± 9%    ~     (p=0.905 n=14+13)
Compiler   4.17user-s ± 1%  4.26user-s ± 7%    ~     (p=1.000 n=2+2)
SSA        6.79user-s ± 8%  6.79user-s ± 6%    ~     (p=0.902 n=15+15)
Flate      169user-ms ± 8%  164user-ms ± 5%  -3.13%  (p=0.014 n=14+14)
GoParser   212user-ms ± 7%  217user-ms ±22%    ~     (p=1.000 n=13+15)
Reflect    521user-ms ± 7%  533user-ms ±15%    ~     (p=0.511 n=14+14)
Tar        165user-ms ±17%  161user-ms ±15%    ~     (p=0.345 n=15+15)
XML        294user-ms ±11%  292user-ms ±10%    ~     (p=0.839 n=14+14)

name       old alloc/op     new alloc/op     delta
Template       39.9MB ± 0%      39.9MB ± 0%    ~     (p=0.621 n=15+14)
Unicode        31.0MB ± 0%      31.0MB ± 0%    ~     (p=0.098 n=13+15)
GoTypes         117MB ± 0%       117MB ± 0%    ~     (p=0.775 n=15+15)
Compiler        488MB ± 0%       488MB ± 0%    ~     (p=0.333 n=2+2)
SSA             892MB ± 0%       892MB ± 0%  +0.03%  (p=0.000 n=15+15)
Flate          26.1MB ± 0%      26.1MB ± 0%    ~     (p=0.098 n=15+15)
GoParser       31.8MB ± 0%      31.8MB ± 0%    ~     (p=0.525 n=15+13)
Reflect        81.2MB ± 0%      81.2MB ± 0%  +0.06%  (p=0.001 n=12+14)
Tar            27.5MB ± 0%      27.5MB ± 0%    ~     (p=0.595 n=15+15)
XML            44.1MB ± 0%      44.1MB ± 0%    ~     (p=0.486 n=15+15)

name       old allocs/op    new allocs/op    delta
Template         378k ± 1%        378k ± 0%    ~     (p=0.949 n=15+14)
Unicode          324k ± 0%        324k ± 1%    ~     (p=0.057 n=14+15)
GoTypes         1.15M ± 0%       1.15M ± 0%    ~     (p=0.461 n=15+15)
Compiler        4.39M ± 0%       4.39M ± 0%    ~     (p=0.333 n=2+2)
SSA             7.90M ± 0%       7.90M ± 0%  +0.06%  (p=0.008 n=15+15)
Flate            240k ± 1%        241k ± 0%    ~     (p=0.233 n=15+15)
GoParser         309k ± 1%        309k ± 0%    ~     (p=0.867 n=15+12)
Reflect         1.00M ± 0%       1.00M ± 0%    ~     (p=0.139 n=12+15)
Tar              254k ± 1%        253k ± 1%    ~     (p=0.345 n=15+15)
XML              398k ± 0%        397k ± 1%    ~     (p=0.267 n=15+15)


Change-Id: Ic999a0f456a371c99eebba0f9747263a13836e33
Reviewed-on: https://go-review.googlesource.com/37766
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-04 18:19:06 +00:00
David Lazar
301149b9e4 cmd/internal/obj: avoid duplicate file name symbols
The meaning of Version=1 was overloaded: it was reserved for file name
symbols (to avoid conflicts with non-file name symbols), but was also
used to mean "give me a fresh version number for this symbol."

With the new inlining tree, the same file name symbol can appear in
multiple entries, but each one would become a distinct symbol with its
own version number.

Now, we avoid duplicating symbols by using Version=0 for file name
symbols and we avoid conflicts with other symbols by prefixing the
symbol name with "gofile..".

Change-Id: I8d0374053b8cdb6a9ca7fb71871b69b4dd369a9c
Reviewed-on: https://go-review.googlesource.com/37234
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2017-03-03 21:29:36 +00:00
David Lazar
699175a11a cmd/compile,link: generate PC-value tables with inlining information
In order to generate accurate tracebacks, the runtime needs to know the
inlined call stack for a given PC. This creates two tables per function
for this purpose. The first table is the inlining tree (stored in the
function's funcdata), which has a node containing the file, line, and
function name for every inlined call. The second table is a PC-value
table that maps each PC to a node in the inlining tree (or -1 if the PC
is not the result of inlining).

To give the appearance that inlining hasn't happened, the runtime also
needs the original source position information of inlined AST nodes.
Previously the compiler plastered over the line numbers of inlined AST
nodes with the line number of the call. This meant that the PC-line
table mapped each PC to line number of the outermost call in its inlined
call stack, with no way to access the innermost line number.

Now the compiler retains line numbers of inlined AST nodes and writes
the innermost source position information to the PC-line and PC-file
tables. Some tools and tests expect to see outermost line numbers, so we
provide the OutermostLine function for displaying line info.

To keep track of the inlined call stack for an AST node, we extend the
src.PosBase type with an index into a global inlining tree. Every time
the compiler inlines a call, it creates a node in the global inlining
tree for the call, and writes its index to the PosBase of every inlined
AST node. The parent of this node is the inlining tree index of the
call. -1 signifies no parent.

For each function, the compiler creates a local inlining tree and a
PC-value table mapping each PC to an index in the local tree.  These are
written to an object file, which is read by the linker.  The linker
re-encodes these tables compactly by deduplicating function names and
file names.

This change increases the size of binaries by 4-5%. For example, this is
how the go1 benchmark binary is impacted by this change:

section             old bytes   new bytes   delta
.text               3.49M ± 0%  3.49M ± 0%   +0.06%
.rodata             1.12M ± 0%  1.21M ± 0%   +8.21%
.gopclntab          1.50M ± 0%  1.68M ± 0%  +11.89%
.debug_line          338k ± 0%   435k ± 0%  +28.78%
Total               9.21M ± 0%  9.58M ± 0%   +4.01%

Updates #19348.

Change-Id: Ic4f180c3b516018138236b0c35e0218270d957d3
Reviewed-on: https://go-review.googlesource.com/37231
Run-TryBot: David Lazar <lazard@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2017-03-03 21:29:30 +00:00
Alex Brainman
29f061960d cmd/link: write dwarf sections
Also stop skipping TestExternalLinkerDWARF and
TestDefaultLinkerDWARF.

Fixes #10776.

Change-Id: Ia596a684132e3cdee59ce5539293eedc1752fe5a
Reviewed-on: https://go-review.googlesource.com/36983
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-03-01 04:51:03 +00:00
Alex Brainman
aada49038c cmd/link: write dwarf relocations
For #10776.

Change-Id: I11dd441d8e5d6316889ffa8418df8b58c57c677d
Reviewed-on: https://go-review.googlesource.com/36982
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-03-01 04:49:29 +00:00
Bill O'Farrell
a6b480bc07 cmd/go: implement -buildmode=plugin for s390x
Simple change to allow plugins for linux on s390x

Change-Id: I5c262ab81aac10d1dcb03381a48e5b9694b7a87a
Reviewed-on: https://go-review.googlesource.com/37451
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-02-25 14:31:10 +00:00
Alex Brainman
b32170abdf cmd/link: simplify peemitreloc
No functional changes.

For #10776.

Change-Id: If9a5ef832af116c5802b06a38e0c050d7363f2d5
Reviewed-on: https://go-review.googlesource.com/36981
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-02-21 06:11:39 +00:00
Alex Brainman
d0a978f5b5 cmd/link: reorder pe sections
dwarf writing code assumes that dwarf sections follow
.data and .bss, not .ctors. Make pe section writing code
match that assumption.

For #10776.

Change-Id: I128c3ad125f7d0db19e922f165704a054b2af7ba
Reviewed-on: https://go-review.googlesource.com/36980
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-02-21 06:11:17 +00:00
Alex Brainman
6db4d92e4c cmd/link: do not add __image_base__ and _image_base__ if external linker
The symbols get in a way when using external linker. They are
not associated with a section. And linker fails when
generating relocations for them.

__image_base__ and _image_base__ have been added long time ago.
I do not think they are needed anymore. If I delete them, all
tests still PASS. I tried going back to the commit that added
them to see if I can reproduce original error, but I cannot
build it. I don't have hg version of go repo, and my gcc is
complaining about cc source code.

I wasted too much time with this, so I decided to leave them only
for internal linker. That is what they were originally added for.

For #10776.

Change-Id: Ibb72b04f3864947c782f964a7badc69f4b074e25
Reviewed-on: https://go-review.googlesource.com/36979
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-02-21 06:10:51 +00:00
Alex Brainman
b660a4b04d cmd/link: add all pe section names to pe symbol table
dwarf relocations refer to dwarf section symbols, so dwarf
section symbols must be present in pe symbol table before we
write dwarf relocations.

.ctors pe section already refer to .text symbol.

Write all pe section name symbols into symbol table, so we
can use them whenever we need them.

This CL also simplified some code.

For #10776.

Change-Id: I9b8c680ea75904af90c797a06bbb1f4df19e34b6
Reviewed-on: https://go-review.googlesource.com/36978
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-21 05:52:04 +00:00
Alex Brainman
e9abf1a716 cmd/link: introduce shNames
Introduce a slice that keeps long pe section names as we add them.
It will be used later to output pe symbol table and dwarf relocations.

For #10776.

Change-Id: I02f808a456393659db2354031baf1d4f9e0b2d61
Reviewed-on: https://go-review.googlesource.com/36977
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-21 05:41:43 +00:00
Alex Brainman
a7e2556255 cmd/link: set VirtualAddress to 0 for external linker
This is what gcc does when it generates object files.
And pecoff.doc says: "for simplicity, compilers should
 set this to zero". It is easier to count everything,
when it starts from 0. Make go linker do the same.

For #10776.

Change-Id: Iffa4b3ad86160624ed34adf1c6ba13feba34c658
Reviewed-on: https://go-review.googlesource.com/36976
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-21 01:05:55 +00:00
Alex Brainman
0ad247c6f0 cmd/link: delay calculating pe file parameters after Linkmode is set
For #10776.

Change-Id: Id64a7e35c7cdcd9be16cbe3358402fa379090e36
Reviewed-on: https://go-review.googlesource.com/36975
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-16 04:35:36 +00:00
Alex Brainman
e31144f128 cmd/link: set pe section and file alignment to 0 during external linking
This is what gcc does when it generates object files.
And it is easier to count everything, when it starts from 0.
Make go linker do the same.

gcc also does not output IMAGE_OPTIONAL_HEADER or
PE64_IMAGE_OPTIONAL_HEADER for object files.
Perhaps we should do the same, but not in this CL.

For #10776.

Change-Id: I9789c337648623b6cfaa7d18d1ac9cef32e180dc
Reviewed-on: https://go-review.googlesource.com/36974
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-02-16 04:33:17 +00:00
Daniel Martí
99df7c9caa cmd/link, crypto/tls: don't use append loops
Change-Id: Ib47e295e8646b769c30fd81e5c7f20f964df163e
Reviewed-on: https://go-review.googlesource.com/36335
Reviewed-by: Filippo Valsorda <hi@filippo.io>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-07 16:42:32 +00:00
David Crawshaw
ab067cde34 cmd/link: use external linking for PIE by default
Now `go test -buildmode=pie std -short` passes on linux/amd64.

Updates #18968

Change-Id: Ide21877713e00edc64c1700c950016d6bff8de0e
Reviewed-on: https://go-review.googlesource.com/36417
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-06 23:04:46 +00:00
Alex Brainman
c7a7c5a9b4 cmd/link: do not prefix external symbols with underscore on windows/386/cgo
CL 18057 added underscore to most external pe symbols
on windows/386/cgo. The CL changed runtime.epclntab and
runtime.pclntab pe symbols into _runtime.pclntab and
_runtime.epclntab, and now cmd/nm cannot find them.
Revert correspondent CL 18057 changes, because most pe
symbols do not need underscore prefix.

This CL also removes code that added obj.SHOSTOBJ symbols
explicitly, because each of those was also added via
genasmsym call. These created duplicate pe symbols (like
_GetProcAddress@8 and __GetProcAddress@8), and external
linker would complain.

This CL adds new test in cmd/nm to verify go programs
built with cgo.

Fixes #18416

Change-Id: I68b1be8fb631d95ec69bd485c77c79604fb23f26
Reviewed-on: https://go-review.googlesource.com/35076
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-04 05:56:45 +00:00