146 Commits

Author SHA1 Message Date
Jeff R. Allen
d7ac9bb992 cmd/compile: do not write slices/strings > 2g
The linker will refuse to work on objects larger than
2e9 bytes (see issue #9862 for why).

With this change, the compiler gives a useful error
message explaining this, instead of leaving it to the
linker to give a cryptic message later.

Fixes #1700.

Change-Id: I3933ce08ef846721ece7405bdba81dff644cb004
Reviewed-on: https://go-review.googlesource.com/74330
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-11-09 18:50:22 +00:00
Joe Tsai
08f19bbde1 go/printer: forbid empty line before first comment in block
To improve readability when exported fields are removed,
forbid the printer from emitting an empty line before the first comment
in a const, var, or type block.
Also, when printing the "Has filtered or unexported fields." message,
add an empty line before it to separate the message from the struct
or interfact contents.

Before the change:
<<<
type NamedArg struct {

        // Name is the name of the parameter placeholder.
        //
        // If empty, the ordinal position in the argument list will be
        // used.
        //
        // Name must omit any symbol prefix.
        Name string

        // Value is the value of the parameter.
        // It may be assigned the same value types as the query
        // arguments.
        Value interface{}
        // contains filtered or unexported fields
}
>>>

After the change:
<<<
type NamedArg struct {
        // Name is the name of the parameter placeholder.
        //
        // If empty, the ordinal position in the argument list will be
        // used.
        //
        // Name must omit any symbol prefix.
        Name string

        // Value is the value of the parameter.
        // It may be assigned the same value types as the query
        // arguments.
        Value interface{}

        // contains filtered or unexported fields
}
>>>

Fixes #18264

Change-Id: I9fe17ca39cf92fcdfea55064bd2eaa784ce48c88
Reviewed-on: https://go-review.googlesource.com/71990
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-11-02 18:17:22 +00:00
Alessandro Arzilli
018642d6cf compile, link: remove base address selector from DWARF range lists
Dsymutil, an utility used on macOS when externally linking executables,
does not support base address selector entries in debug_ranges.

To work around this deficiency this commit removes base address
selectors from debug_ranges and emits instead a list composed only of
compile unit relative addresses.

A new type of relocation is introduced, R_ADDRCUOFF, similar to
R_ADDROFF, that relocates an address to its offset from the low_pc of
the symbol's compile unit.

Fixes #21945

Change-Id: Ie991f9bc1afda2b49ac5d734eb41c37d3a37e554
Reviewed-on: https://go-review.googlesource.com/72371
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2017-11-01 14:35:30 +00:00
Daniel Martí
7cb3e4fb1d all: unindent some if bodies by exiting early
All of these had a return or break in the else body, so flipping the
condition means we can unindent and simplify.

Change-Id: If93e97504480d18a0dac3f2c8ffe57ab8bcb929c
Reviewed-on: https://go-review.googlesource.com/74190
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-31 20:07:46 +00:00
Than McIntosh
b52b77cb95 cmd/compile, cmd/link: support for DWARF file reference relocations
New relocation flavor R_DWARFFILEREF, to be applied to DWARF attribute
values that correspond to file references (ex: DW_AT_decl_file,
DW_AT_call_file). The LSym for this relocation is the file itself; the
linker replaces the relocation target with the index of the specified
file in the line table's file section.

Note: for testing purposes this patch changes the DWARF function
subprogram DIE abbrev to include DW_AT_decl_file (allowed by DWARF
but not especially useful) so as to have a way to test this
functionality. This attribute will be removed once there are other
file reference attributes (coming as part of inlining support).

Change-Id: Icf676beb60fcc33f06d78e747ef717532daaa3ba
Reviewed-on: https://go-review.googlesource.com/73330
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2017-10-27 17:53:52 +00:00
David Crawshaw
6355d6c7e2 cmd/link, plugin: always encode path
Both the linker and the plugin package were inconsistent
about when they applied the path encoding defined in
objabi.PathToPrefix. As a result, only some symbols from
a package path that required encoding were being found.

So always encoding the path.

Fixes #22295

Change-Id: Ife86c79ca20b2e9307008ed83885e193d32b7dc4
Reviewed-on: https://go-review.googlesource.com/72390
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-26 15:08:37 +00:00
Michael Hudson-Doyle
1b8987f1a7 cmd/link: replace SSUB with an attribute bit
There is some stuff I don't understand very well involved in SSUB, better words
for the documentation gratefully accepted.

As this is the last use of a bit in SMASK, kill that off too.

Change-Id: Iddff1c9b2af02c9dfb12ac8e668d004e4642f997
Reviewed-on: https://go-review.googlesource.com/42026
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-10-24 23:06:28 +00:00
David Crawshaw
38cfeb9cb5 cmd/link: move Headtype global to ctxt
For #22095

Change-Id: Idcfdfe8a94db8626392658bb93429454238f648a
Reviewed-on: https://go-review.googlesource.com/70835
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-21 00:51:14 +00:00
David Crawshaw
d05f82a11a cmd/link: move Iself global to ctxt
For #22095

Change-Id: Iba3dffc782cecc15ea0e90a971a2734729984945
Reviewed-on: https://go-review.googlesource.com/70834
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-20 23:41:16 +00:00
David Crawshaw
6738c494ad cmd/link: move FlagLinkshared global to ctxt
For #22095

Change-Id: Ica6b3391541fe5a0355620d7c4a5107cf53eee82
Reviewed-on: https://go-review.googlesource.com/70833
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-20 23:40:56 +00:00
Michael Hudson-Doyle
1341104ae2 cmd/link: replace SHIDDEN bit in SymKind with a bit of Attribute
This is https://go-review.googlesource.com/42025 but with some more fixes --
hidden symbols implicitly passed "Type == 0 || Type == SXREF" checks. (This
sort of thing is part of why I wanted to make this change)

Change-Id: I2273ee98570fd7f2dd8a799c692a2083c014235e
Reviewed-on: https://go-review.googlesource.com/42330
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-16 06:40:13 +00:00
Heschi Kreinick
a0402b6bf8 cmd/link: suppress unnecessary DWARF relocs that confuse dsymutil
During Mach-O linking, dsymutil takes the DWARF from individual object
files and combines it into a debug archive. Because it's content-aware,
it doesn't need our help to do its job. Nonetheless, it does try to
honor relocations that are present in its input.

When dsymutil encounters a relocation, it uses the value of that
relocation as an index into the debug map to find its final location.
When it does that, it's assuming that the value is an address in the
object file. But DWARF references are section-relative. So when it
processes a relocation for a DWARF reference, it gets confused,
and if the value happens to match the address of a function or
data symbol, it will rewrite it incorrectly.

Since the relocations don't help, and can hurt, drop them when
externally linking a Mach-O binary.

Fixes #22068

Change-Id: I8ec36da626575d9f6c8d0e7a0b76eab8ba22d62c
Reviewed-on: https://go-review.googlesource.com/68330
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-10-12 18:51:54 +00:00
David Crawshaw
f7ad3a04f9 cmd/link: move ldmacho to its own package
For #22095

Change-Id: I660080279692b74669c45f42c28cccff71bd33b5
Reviewed-on: https://go-review.googlesource.com/68930
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-10-06 22:01:22 +00:00
David Crawshaw
2e8545531e cmd/link: move build/link mode globals into ctxt
Replace Buildmode with BuildMode and Linkmode with LinkMode.

For #22095

Change-Id: I51a6f5719d107727bca29ec8e68e3e9d87e31e33
Reviewed-on: https://go-review.googlesource.com/68334
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-10-06 13:49:11 +00:00
Marvin Stenger
90d71fe99e all: revert "all: prefer strings.IndexByte over strings.Index"
This reverts https://golang.org/cl/65930.

Fixes #22148

Change-Id: Ie0712621ed89c43bef94417fc32de9af77607760
Reviewed-on: https://go-review.googlesource.com/68430
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-05 23:19:10 +00:00
David Crawshaw
475d92ba4d cmd/link: put symbol data types in new package
For #22095

Change-Id: I07c288208d94dabae164c2ca0a067402a8e5c2e6
Reviewed-on: https://go-review.googlesource.com/68331
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-05 10:50:18 +00:00
David Crawshaw
0346664421 cmd/link: convert symbol Add* functions to methods
Also reduce the passed context from *Link to *sys.Arch, so fewer
data dependencies need to be wired through all the code dealing
with symbols.

For #22095

Change-Id: I50969405d6562c5152bd1a3c443b72413e9b70bc
Reviewed-on: https://go-review.googlesource.com/67313
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-04 12:22:30 +00:00
David Crawshaw
273b657b4e cmd/link: support -X values for main.* in plugins
Fixes #19418

Change-Id: I98205f40c1915cd68a5d20438469ba06f1efb160
Reviewed-on: https://go-review.googlesource.com/67432
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-04 00:46:06 +00:00
David Crawshaw
5fe9bbcf63 cmd/link: remove coutbuf global variable
Begin passing coutbuf by as a parameter. To make the initial plumbing
pass easier, it is also a field in the standard ctxt parameter.

Consolidate the byte writing functions into the OutBuf object.
The result is less architecture-dependent initialization.

To avoid plumbing out everywhere we want to report an error, move
handling of out file deletion to an AtExit function.

For #22095

Change-Id: I0863695241562e0662ae3669666c7922b8c846f9
Reviewed-on: https://go-review.googlesource.com/67318
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-04 00:37:27 +00:00
David Crawshaw
5d95de2072 cmd/link: remove SysArch global variable
For #22095

Change-Id: I9d1f0d93f8fd701a24af826dc903eea2bc235de2
Reviewed-on: https://go-review.googlesource.com/67317
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-03 23:32:02 +00:00
Dave Cheney
ed815d0038 cmd/link/internal/ld: reduce the scope of some local declarations
Move some local declarations closer to their use, reducing their
respective lifetimes. Spotted while reviewing CL 67318.

Change-Id: I68db67fe8530344d95e50efb6587bc724e1171f5
Reviewed-on: https://go-review.googlesource.com/67370
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-10-01 22:00:18 +00:00
Marvin Stenger
f22ba1f247 all: prefer strings.IndexByte over strings.Index
strings.IndexByte was introduced in go1.2 and it can be used
effectively wherever the second argument to strings.Index is
exactly one byte long.

This avoids generating unnecessary string symbols and saves
a few calls to strings.Index.

Change-Id: I1ab5edb7c4ee9058084cfa57cbcc267c2597e793
Reviewed-on: https://go-review.googlesource.com/65930
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-25 17:35:41 +00:00
Hiroshi Ioka
410b73728f cmd/link: remove windows-specific kludges from Adddynrel
Adddynrel does nothing on windows. We can make code don't call Adddynrel
on windows in the first place.

Change-Id: I376cc36d44a5df18bda13be57e3916ca3062f181
Reviewed-on: https://go-review.googlesource.com/62611
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2017-09-10 23:19:52 +00:00
Hiroshi Ioka
f58c48f834 cmd/link: extract windows-specific code from dynrelocsym
No functional changes.

Change-Id: Ib31bb3f01b515aac6428ec61e0ef02b269623890
Reviewed-on: https://go-review.googlesource.com/62470
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-09-09 07:06:23 +00:00
Hiroshi Ioka
0c4d035ca8 cmd/link: refactor *reloc
* use bool instead of int if it's adequate.
* remove blank lines.

Change-Id: Ic4a5644a33ed9fc7ce388ef8ba15f1732446fcfc
Reviewed-on: https://go-review.googlesource.com/59375
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-28 05:42:48 +00:00
Hiroshi Ioka
37b04c9062 cmd/link: fix debug message
Change-Id: I6cb0ed9b726da34106ba239b57e2da732a8e1b71
Reviewed-on: https://go-review.googlesource.com/50730
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Avelino <t@avelino.xxx>
2017-08-25 22:49:00 +00:00
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
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
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
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
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
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
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 a69222d949bcc2c4453248ee233b63b75d79967e.

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
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
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
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
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
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 c8b889cc4824f4dbd64a51a3f7b5b6dce4b87ed2.

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
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
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
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
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