Commit graph

171 commits

Author SHA1 Message Date
Than McIntosh
da9f383ca1 [dev.link] cmd/link: set direct fn address in dwarf gen where possible
If we are internal linking a static executable, and address assignment
has happened, then when emitting some parts of DWARF we can just emit
a function address directly instead of generating a relocation. For
external linking or other build modes, we are generating a relocatable
binary so we still need to emit relocations.

This CL inspired by Cherry's similar CL for pclntab at
https://go-review.googlesource.com/c/go/+/228478.

Change-Id: Ib03fbe2dd72d0ba746bf46015e0f2d6c3f3d53ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/228537
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-16 15:40:34 +00:00
Than McIntosh
eed3ef581b [dev.link] cmd/link: hoist dwarfGenerateDebugSyms out of dodata()
Hoist dwarfGenerateDebugSyms call up out of dodata to before
loadlibfull. This required a couple of small tweaks to the
loader and to loadlibfull.

Change-Id: I48ffb450d2e48b9e55775b73a6debcd27dbb7b9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/228221
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-14 19:36:56 +00:00
Cherry Zhang
5072c166a1 [dev.link] cmd/link: return package path in SymFile
SymFile, derived from sym.Symbol.File, is supposed to return the
package path, instead of the file name (arguably the name is
confusing). Make it so, and rename it to SymPkg.

Change-Id: I67bcd12f67cea271f2a2ce3c5724e5d228f5b2f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/227481
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-04-08 15:28:34 +00:00
Cherry Zhang
0e0ee115c5 [dev.link] cmd/link: unify Relocs.Count and len(rs)
The Count field in Relocs type is always equal to len(rs). Unify
them.

Change-Id: Ic77288ea58b61a98482b218e051d81047d0ddd88
Reviewed-on: https://go-review.googlesource.com/c/go/+/226717
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-31 23:02:36 +00:00
Cherry Zhang
6e3bde5f30 [dev.link] cmd/link: store external relocations in Reloc2 format
Store external relocations in (almost) the same format as the Go
objects, so we can handle them more uniformly.

There is a small speedup:

(linking cmd/compile)
Deadcode        67.8ms ± 3%    61.1ms ± 3%   -9.94%  (p=0.008 n=5+5)
Dostkcheck      41.2ms ± 2%    38.8ms ± 3%   -5.99%  (p=0.008 n=5+5)

Change-Id: I8616e10b26235904201d6c9465f5ae32a49c9949
Reviewed-on: https://go-review.googlesource.com/c/go/+/226365
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-31 23:02:16 +00:00
Cherry Zhang
b1a19f3cc7 [dev.link] cmd/link: convert doxcoff to new style
Change-Id: Ic1e4ed6c14e049b1ba2f7c00f986433ab7ebe932
Reviewed-on: https://go-review.googlesource.com/c/go/+/225202
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-03-25 15:20:40 +00:00
Than McIntosh
3fa98a0436 [dev.link] cmd/link: minor tweaks to PropagateLoaderChangesToSymbols
Update PropagateLoaderChangesToSymbols so that it no longer requires
a sym.Symbols pointer. The intent is to generalize it a little to
allow it to be used in more than just linker Dwarf generation.

Change-Id: I9bddc5d39839eacd9113c945bb59d2873c0b088c
Reviewed-on: https://go-review.googlesource.com/c/go/+/224381
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-03-25 12:22:56 +00:00
Than McIntosh
0dff5b0b9e [dev.link] cmd/compile, cmd/link: move away from DWARF file renumbering
This patch moves the compiler and linker away from the current scheme
used to generate file references in DWARF subprogram dies.

Up until now the scheme has been to have the compiler emit a special
relocation on a DIE file reference that points to the file symbol in
question. The linker then reads this relocation and updates the addend
to the index of the appropriate file in the line table of the
compilation unit of the DIE (the linker emits the comp unit file
table, so it knows at that point what number use). The drawback of
this scheme is that it requires a lot of relocation processing.

With this patch, we switch to having the compiler emit the file index
directly, and then have the linker use the compiler-generated file
table to emit the line table file section (no renumbering, no
relocations, etc).

Change-Id: Id4fbe67b28a64200a083e3c5ea358dbe091ec917
Reviewed-on: https://go-review.googlesource.com/c/go/+/223318
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-20 16:19:22 +00:00
Than McIntosh
673a02a235 [dev.link] cmd/compile, cmd/link: move DWARF info sym to anonymous aux data
Switch the primary subprogram die DWARF symbol emitted by the compiler
from named+dupOK to anonymous aux. This should help performance wise
by not having to add these symbols to the linker's symbol name lookup
tables.

Change-Id: Idf66662b8bf60b3dee9a55e6cd5137b24a9f5ab6
Reviewed-on: https://go-review.googlesource.com/c/go/+/223669
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-20 16:19:15 +00:00
Cherry Zhang
626c89bfa3 [dev.link] cmd/link: remove AddExtSym
They used to be different at some point, but now AddExtSym and
LookupOrCreateSym are identical. Remove one.

Change-Id: I299444d987e32a7f43915b3c1bbcc5ae906e9b6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/223977
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-03-18 22:26:24 +00:00
Cherry Zhang
61a0b0d624 [dev.link] cmd/link: use new relocation accessors in DWARF generation
This gives some speedup and reduces some allocations:

(linking cmd/compile)
DwarfGenerateDebugInfo    63.2ms ± 3%    41.7ms ± 3%  -34.04%  (p=0.008 n=5+5)

DwarfGenerateDebugInfo    20.0MB ± 0%    10.1MB ± 0%  -49.62%  (p=0.008 n=5+5)

There are code that modify relocations, which are still using
the earlier loader.Reloc slice for now.

Change-Id: I3359ba305bf82cc882ae3c0f548d6ccfc8add789
Reviewed-on: https://go-review.googlesource.com/c/go/+/223663
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-03-16 17:33:50 +00:00
Than McIntosh
8634642f9a [dev.link] cmd/link: demote dwarf {range,loc} sub-symbols to aux
When the compiler emits DWARF for a function F, in addition to the
text symbol for F, it emits a set of sibling or child symbols that
carry the various DWARF bits for F (for example, go.info.F,
go.ranges.F, go.loc.F, and so on).

Prior to the linker modernization work, name lookup was the way you
made your way from a function symbol to one of its child DWARF
symbols. We now have a new mechanism (aux symbols), so there is really
no need for the DWARF sub-symbols to be named or to be dupok.

This patch converts DWARF "range" and "loc" sub-symbols to be pure aux
syms: unnamed, and connected to their parent text symbol only via aux
data. This should presumably have performance benefits in that we add
fewer symbols to the linker lookup tables.

Other related DWARF sub-symbols (ex: go.line.*) will be handled in a
subsequent patch.

Change-Id: Iae3ec2d42452962d4afc1df4a1bd89ccdeadc6e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/222673
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-12 18:56:09 +00:00
Than McIntosh
a6ae6d35e6 [dev.link] cmd/link: remove unnecessary file processing from writelines
The linker DWARF-gen's line table writing routine contains a loop that
walks all abstract function DIEs looking for files that aren't
referenced in concrete function DIEs. Turns out this loop is no longer
necessary, most likely because the compiler emits an explicit DWARF
file table into the object file.

This patch removes the offending loop. This is a prelude to some
additional work that will hopefully get rid of file renumbering in
writelines altogether (still WIP).

Change-Id: I3b3a9acce1bae7dda878ab6de2d3436de302712e
Reviewed-on: https://go-review.googlesource.com/c/go/+/223145
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-12 18:36:55 +00:00
Than McIntosh
b0b185c5fa [dev.link] cmd/link: remove patchDWARFName from the linker
Remove the various bits of code in the linker that patch DWARF name
attributes (rewrite "". to packagepath).

Change-Id: I29a38d680d411ccf1c1eeb760f2d15fc8ec22d90
Reviewed-on: https://go-review.googlesource.com/c/go/+/222719
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-10 18:59:18 +00:00
Than McIntosh
cdc1b19513 [dev.link] cmd/link: remove legacy DWARF gen code
Remove the temporary "-newdw2" linker command line option, along with
the remainder of the legacy sym.Symbol based DWARF generation code.

Change-Id: I86c0581dd021cd4e2209ca9bc45f34037d42323c
Reviewed-on: https://go-review.googlesource.com/c/go/+/222766
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-10 17:49:39 +00:00
Than McIntosh
69d9664f18 [dev.link] cmd/link: use shared reloc slice in writelines method
Move to a shared/reused slice of loader.Reloc's in a couple of places
in the linker's DWARF writelines method, as opposed to allocating a
new slice each time. Small performance improvement.

Change-Id: I06c64cf7ca00162d24d9421f1d6405c8808ebb83
Reviewed-on: https://go-review.googlesource.com/c/go/+/222758
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-10 17:19:08 +00:00
Than McIntosh
efbab6dc7d [dev.link] cmd/link: fix up stray references to legacy "newdie" function
In a couple of places in the DWARF type generation code there were
calls to the older sym.Symbol "newdie" funtion as opposed to the
loader.Sym based method. This patch converts these to method calls.

Change-Id: I202957464b7c37063ff74e834ed7b76d1dc5bcdf
Reviewed-on: https://go-review.googlesource.com/c/go/+/222757
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-10 17:18:55 +00:00
Than McIntosh
24064a302c [dev.link] cmd/link: check for dwarf enabled in loadlibfull
Check dwarfEnabled before invoking dwarfConvertSymbols (not needed if
we're not doing dwarf gen).

Change-Id: Id7ea7d11c13524705d305596bf1468d4858216b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/222157
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-03-10 14:17:13 +00:00
Than McIntosh
0c41a37c6c [dev.link] cmd/link: convert second phase of DWARF-gen to use loader
This converts the second portion of DWARF-gen (dwarfGenerateDebugSyms
function and friends) to use the loader, as opposed to sym.Symbols.

Second phase is invoked as part of dodata(), which is fairly far along
in the linker, meaning that the "converted to loader.Symbol" wavefront
has not yet reached that point.

To account for this, the patch contains some shim code that runs
initially to copy back things from sym.Symbols into the loader
(notable symbol values), and then a second hook to be code after
dwarf-gen is complete to that copies the results back into the
appropriate sym.Symbols. This code is obviously temporary, but needed
for the time being.

Change-Id: I9b830b08b16480a1a5230cb52b592db1c550af18
Reviewed-on: https://go-review.googlesource.com/c/go/+/220987
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-03-05 16:50:21 +00:00
Than McIntosh
85d62a91ee [dev.link] cmd/link: fix up ctxt.Textp2 handling in AssignTextSymbolOrder
Change the loader method AssignTextSymbolOrder to return a slice of
all reachable textp symbols, since it will be needed in second-phase
DWARF gen.

Change-Id: Iaf16ee9cf0d5266aeb0d3df596e8117263b35d8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/220985
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-03-05 16:20:42 +00:00
Than McIntosh
b7d5346889 [dev.link] cmd/link: remove -newdw flag for phase 1 DWARF gen
Remove the "-newdw" command line option, a temporary placeholder/gate
for the first phase of new DWARF gen, along with some portions of the
sym.Symbol based DWARF type gen code. The remainder of the old code
will be removed in a subsequent patch.

Change-Id: I7870539f020fbf05d0345d3af2acf383fae94892
Reviewed-on: https://go-review.googlesource.com/c/go/+/220984
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-03-02 13:35:06 +00:00
Than McIntosh
48c79db07f [dev.link] cmd/link: simplify DWARF DIE symbol payload
Get rid of of the linker's dwSym struct (which wraps a loader.Loader
and a loader.Sym) in favor of just loader.Sym. This requires some minor
tweaks to the cmd/internal/dwarf interfaces.

Change-Id: Id3ffd7c41b2433ea04417040368700334bb0e611
Reviewed-on: https://go-review.googlesource.com/c/go/+/220982
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-02-27 20:26:16 +00:00
Than McIntosh
25f1b093fe [dev.link] cmd/link: convert DWARF type generation to use loader
Converts the portion of DWARF generation that deals with creation of
type DIEs and constant DIEs to use the new loader interfaces. Creation
of subprogram DIE and compilation unit DIE content still operates on
sym.Symbols at the moment, and happens much later in the linker.

The new code for type DIE generation is gated/guarded by the linker
flag "-newdw", which currently defaults to true. At some point in the
near future this flag should be removed, but it is handy for triage at
the moment.

This patch also includes shim code designed to run after loadlibfull()
that walks through the DIE chains and to converts loader.Sym
references back into sym.Symbol references for the remainder of the
compilation, since the second phase of DWARF has not yet been
converted.

Change-Id: I681a00fb8a1f3c37884a79b373d86411332e07c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/208230
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-02-19 21:15:12 +00:00
Ville Skyttä
440f7d6404 all: fix a bunch of misspellings
Change-Id: I5b909df0fd048cd66c5a27fca1b06466d3bcaac7
GitHub-Last-Rev: 778c5d2131
GitHub-Pull-Request: golang/go#35624
Reviewed-on: https://go-review.googlesource.com/c/go/+/207421
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-11-15 21:04:43 +00:00
Than McIntosh
795e8c2317 cmd/go: address DWARF linker issues with -buildmode=plugin on Darwin
Assorted fixups in the linker needed to enable turning back on
DWARF generation when building plugins for Darwin. Includes:

 - don't suppress import of runtime/cgo in the linker for
   Darwin if we are linking in plugin mode

 - in calcCompUnitRanges handle the case where we encounter
   linker-generated functions that have no associated Unit (and
   also have no DWARF)

 - generalize a guard in relocsym() include so as to avoid
   triggering a spurious error on go.info symbols in plugin mode

Updates #21647.
Updates #27502.

Change-Id: I317fea97bef2f3461e31498e63f9fd6d8b8f4b23
Reviewed-on: https://go-review.googlesource.com/c/go/+/182959
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
2019-11-11 17:37:48 +00:00
Than McIntosh
c0555a2a7a [dev.link] all: merge branch 'master' into dev.link
Fixed a couple of minor conflicts in lib.go and deadcode.go
relating to debug logging.

Change-Id: I58335fc42ab1f1f3409fd8354da4f26419e8fb22
2019-11-01 10:45:24 -04:00
nikita-vanyasin
c3e8a20a65 cmd/link/internal: eliminate all ld.Cputime() usages
Also a similar 'elapsed' function and its usages were deleted.

Fixes #19865.

Change-Id: Ib125365e69cf2eda60de64fa74290c8c7d1fd65a
Reviewed-on: https://go-review.googlesource.com/c/go/+/171730
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2019-10-26 05:40:14 +00:00
Cherry Zhang
c455e8878f [dev.link] cmd/link: change some decodetype functions to operate on bytes
Change some decodetype functions to operate on bytes nstead of
Symbol. This is in preparation of implementing live method
tracking in index-based deadcode pass, and reducing/eliminating
sym.Symbol in general.

Change-Id: Ia9809ad7b182884225e1bda577e8dbec0cd216c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/199077
Reviewed-by: Austin Clements <austin@google.com>
2019-10-09 21:05:54 +00:00
Than McIntosh
e72f002ed0 cmd/link: create DWARF types for autos based R_USETYPE relocs
Switch the linker over to use dummy R_USETYPE relocations on DWARF
subprogram DIEs as a means of insuring that DWARF types are created
for types of autotmp values used in live functions.

This change is part of a series intended to clean up handling of
autotmp types and remove use of autom's in the compiler and linker.

Updates #34554.

Change-Id: Ic74da6bd723ab7e4d8a16ad46e23228650d4b525
Reviewed-on: https://go-review.googlesource.com/c/go/+/197498
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2019-09-27 13:56:45 +00:00
Jeremy Faller
8506b7d42f cmd/link: switch linker over to new debug lines from compiler
This switches the linker over to using the new debug_lines data
generated in the compiler.

Change-Id: If8362d6fcea7db60aaebab670ed6f702ab1c4908
Reviewed-on: https://go-review.googlesource.com/c/go/+/191968
Run-TryBot: Jeremy Faller <jeremy@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-09-26 14:16:54 +00:00
Jeremy Faller
78a3734714 cmd/link: add notion of multiple compilation units per package
As we move the debug_line generation into the compiler, we need to
upgrade the notion of compilationUnit to not just be on a per package
basis.  That won't be the case as it will be impossible for all
compilationUnits to have the same set of files names used to build the
debug_lines table. (For example, assembled files in a package don't know
about any files but themselves, so the debug_lines table could only
reference themseves. As such, we need to break the 1:1 relationship
between compUnit and package.)

Change-Id: I2e517bb6c01de0115bbf777af828a2fe59c09ce8
Reviewed-on: https://go-review.googlesource.com/c/go/+/189618
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-09-24 21:33:10 +00:00
Jeremy Faller
8f816259ee cmd/link: make PCIter available to compiler
I'm branching this off cl/187117, and will be reworking that diff stack.

Testing: I've run go build -toolexec 'toolstash -cmp'

Change-Id: I922a97d0f25d52ea70cd974008a063d4e7af34a7
Reviewed-on: https://go-review.googlesource.com/c/go/+/188023
Reviewed-by: Austin Clements <austin@google.com>
2019-09-23 19:02:02 +00:00
David Chase
807761f334 cmd/link: revert/revise CL 98075 because LLDB is very picky now
This was originally

Revert "cmd/link: fix up debug_range for dsymutil (revert CL 72371)"

which has the effect of no longer using Base Address Selection
Entries in DWARF.  However, the build-time costs of that are
about 2%, so instead the hacky fixup that generated technically
incorrect DWARF was removed from the linker, and the choice
is instead made in the compiler, dependent on platform, but
also under control of a flag so that we can report this bug
against LLDB/dsymutil/dwarfdump (really, the LLVM dwarf
libraries).

This however does not solve #31188; debugging still fails,
but dwarfdump no longer complains.  There are at least two
LLDB bugs involved, and this change will at allow us
to report them without them being rejected because our
now-obsolete workaround for the first bug creates
not-quite-DWARF.

Updates #31188.

Change-Id: I5300c51ad202147bab7333329ebe961623d2b47d
Reviewed-on: https://go-review.googlesource.com/c/go/+/170638
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2019-04-23 20:52:23 +00:00
Cherry Zhang
248444d5eb cmd/link: apply DWARF relocations while doing compression
We are preparing for applying relocations to the output buffer.
However, for DWARF compression, relocations need to be applied
before compression, but we don't have an output buffer at that
time. We also cannot delay DWARF compression to when we mmap the
output file, because we need the size of the DWARF sections to
compute the file size.

Instead of applying all the relocations together, we apply
relocations in DWARF sections one symbol at a time, right before
it is writing out for compression. As the symbol content may be
in read-only memory (in the future), we use a temporary buffer
for applying the relocations, and immediately write it out.

If compression is not used, relocations are still applied all
together.

This is in preparation for mmap'ing input files read-only.

Change-Id: Iae6d2dd71313897d5054bcc458d3bb78075b30c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/171397
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 18:25:20 +00:00
Cherry Zhang
15a31bd9c8 cmd/link: apply R_DWARFFILEREF later
Apply R_DWARFFILEREF relocations later, along with other
relocations, so that we don't modify symbols' contents before
they are written to the output buffer.

This is in preparation for mmap'ing input files read-only.

Change-Id: I8e9ffb2f05acf8f198589b8770f277beb3847541
Reviewed-on: https://go-review.googlesource.com/c/go/+/170740
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 18:25:09 +00:00
Michael Munday
aafe257390 cmd/link, runtime: mark goexit as the top of the call stack
This CL adds a new attribute, TOPFRAME, which can be used to mark
functions that should be treated as being at the top of the call
stack. The function `runtime.goexit` has been marked this way on
architectures that use a link register.

This will stop programs that use DWARF to unwind the call stack
from unwinding past `runtime.goexit` on architectures that use a
link register. For example, it eliminates "corrupt stack?"
warnings when generating a backtrace that hits `runtime.goexit`
in GDB on s390x.

Similar code should be added for non-link-register architectures
(i.e. amd64, 386). They mark the top of the call stack slightly
differently to link register architectures so I haven't added
that code (they need to mark "rip" as undefined).

Fixes #24385.

Change-Id: I15b4c69ac75b491daa0acf0d981cb80eb06488de
Reviewed-on: https://go-review.googlesource.com/c/go/+/169726
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-15 13:17:28 +00:00
Josh Bleecher Snyder
6d64dd731b cmd/link: make Pciter more idiomatic
Rename it to PCIter and convert it to use methods.

Set pcscale once, during construction, to make call sites clearer.

Change some ints to bools.

Use a simple iteration termination condition,
instead of the cap comparison from the c2go translation.

Instead of requiring a Pcdata, which requires one caller
to synthesize a fake Pcdata, just ask for a byte slice.

Passes toolstash-check.

Change-Id: I811da0e929cf4a806bd6d70357ccf2911cd0c737
Reviewed-on: https://go-review.googlesource.com/c/go/+/171770
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-12 21:41:09 +00:00
Alessandro Arzilli
e29f74efb9 compile,link: export package name in debug_info
Add a new custom attribute to compile units containing the package name
of the package (i.e. the name after the 'package' keyword), so that
debuggers can know it when it's different from the last segment
of the package path.

Change-Id: Ieadaab6f47091aabf2f4dc42c8524452eaa6715b
Reviewed-on: https://go-review.googlesource.com/c/go/+/163677
Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2019-04-02 17:40:36 +00:00
Than McIntosh
cacab64555 cmd/link: change -strictdups checking to handle mix of flags
Update the recently-added '-strictdups' sanity checking to avoid
failing the link in cases where we have objects feeding into the link
with a mix of command line flags (and in particular some with "-N" and
some without). This scenario will trigger errors/warnings due to
inlinable functions and wrapper functions that have different sizes
due to presence or lack of optimization.

Update #31034.

Change-Id: I1dd9e37c2f9bea5da0ab82e32e6fc210aebf6a65
Reviewed-on: https://go-review.googlesource.com/c/go/+/169160
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-03-27 17:53:27 +00:00
Clément Chigot
0ff9df6b53 cmd: disable DWARF with old ld on aix/ppc64
DWARF relocations isn't working with some older ld, because of
-Wl,-bnoobjreorder which is needed on Go.
This commit checks ld's version and disable DWARF generation in cmd/link
if it's too old. Some tests must therefore be skipped.

Change-Id: I2e794c263eb0dfe0b42e7062fb80c26f086b44d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/164007
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-13 02:33:58 +00:00
Clément Chigot
3cf89e509b cmd/link: enable DWARF with external linker on aix/ppc64
In order to allow DWARF with ld, the symbol table is adapted.
In internal linkmode, each package is considered as a .FILE. However,
current version of ld is crashing on a few programs because of
relocations between DWARF symbols. Considering all packages as part of
one .FILE seems to bypass this bug.
As it might be fixed in a future release, the size of each package
in DWARF sections is still retrieved and can be used when it's fixed.
Moreover, it's improving internal linkmode which should have done it
anyway.

Change-Id: If3d023fe118b24b9f0f46d201a4849eee8d5e333
Reviewed-on: https://go-review.googlesource.com/c/go/+/164006
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-09 00:25:11 +00:00
Alessandro Arzilli
4d8a37a6d9 cmd/link: fix contents of debug_pubnames/debug_pubtypes
The contents of debug_pubnames and debug_pubtypes have been wrong since
Go 1.12.
CL golang.org/cl/137235 moved global variables DIE to their respective
compilation unit, unfortunately writepub can't emit correct sections
for anything but the first compilation unit.

This commit moves the code generating debug_pubnames and debug_pubtypes
inside writeinfo and fixes it.
Gets rid of a number of unnecessary relocations as well as a hack that
writeinfo used to communicate to writepub the size of each compilation
unit.

Fixes #30573

Change-Id: Ibdaa80c02746ae81661c2cfe1d218092c5ae9236
Reviewed-on: https://go-review.googlesource.com/c/go/+/165337
Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2019-03-06 23:18:15 +00:00
Clément Chigot
80f10965ee cmd/link, runtime: allow external linking for aix/ppc64
This commit adds external linking in cmd/link for aix/ppc64.
As relocations on .text data aren't possible on AIX, Segrelrodata is
used to move all these datas to .data section.

Change-Id: I4d1361c1fc9290e11e6f5560864460c76551dbeb
Reviewed-on: https://go-review.googlesource.com/c/go/+/164003
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-06 15:32:25 +00:00
Clément Chigot
ed2fce2d87 cmd/link: support dwarf64 when writing .debug_frame
Fixes #28558

Change-Id: I0ecd9c47fb017cf4bd44725a83a0016c7bb94633
Reviewed-on: https://go-review.googlesource.com/c/go/+/156478
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-03-06 05:24:22 +00:00
Austin Clements
8dba66dfeb cmd/link: fix isStmt DWARF info
When CL 147160 introduced function ABIs encoded as symbol versions in
the linker, it became slightly more complicated to look up derived
DWARF symbols. It fixed this by introducing a dwarfFuncSym function to
hide this logic, but missed one derived lookup that was done in the
object reader itself. As a result, we lost the isStmt tables from the
compiler, so every PC was marked as a statement in the DWARF info.

Fix this by moving this derived lookup out of the object reader and
into the DWARF code and calling dwarfFuncSym to get the correctly
versioned symbol.

Should fix the linux-amd64-longtest builder.

Updates #27539.

Change-Id: If40d5ba28bab1918ac4ad18fbb5103666b6d978b
Reviewed-on: https://go-review.googlesource.com/c/149605
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-11-14 22:01:38 +00:00
Austin Clements
14560da7e4 cmd/link: start file-local symbols at version 10
We're going to use the linker's symbol versions to track ABIs.
Currently, version 0 is used for global symbols and version > 0 is
used for file-local symbols. This CL reserves versions 0 to 9 for
global symbols with ABIs and uses version 10 and up for file-local
symbols. To make this clean, it also introduces a method on Symbol for
querying whether it's file-local.

For #27539.

Change-Id: Id3bc7369268f35128b14318a62e86335181a80e5
Reviewed-on: https://go-review.googlesource.com/c/146859
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2018-11-12 20:27:22 +00:00
Austin Clements
ec4ae29f52 cmd/link: abstract DWARF metadata symbol lookup
The compiler passes a lot of DWARF metadata about functions to the
linker via symbols whose names are derived from the function's own
symbol name. We look up these symbols in several places. This is about
to get slightly more complex as we introduce ABIs as symbol versions,
so abstract this lookup pattern into a helper function.

For #27539.

Change-Id: Ic71f6b5dc6608a5a5f5f515808981e6d6f5d728e
Reviewed-on: https://go-review.googlesource.com/c/146858
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2018-11-12 20:27:21 +00:00
Clément Chigot
75a0b9dbf3 cmd: add DWARF64 support for aix port
This commit adds support for DWARF 64bits which is needed for AIX
operating system.

It also adds the save of each compilation unit's size which will be
used during XCOFF generation in a following patch.

Updates: #25893

Change-Id: Icdd0a4dd02bc0a9f0df319c351fb1db944610015
Reviewed-on: https://go-review.googlesource.com/c/138729
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-10-24 13:36:43 +00:00
Alessandro Arzilli
ffbf479ae1 cmd/compile,cmd/link: remove statictmp variables from symbol table.
Removes statictmp variables from debug_info and the final symbol table.

Fixes #27800

Change-Id: I302c59a04bc3f460e7085fef241f937bbf30421d
Reviewed-on: https://go-review.googlesource.com/c/142577
Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2018-10-22 17:58:16 +00:00
Alessandro Arzilli
1c8943bd59 cmd/link: move DIE of global variables to their compile unit
The DIEs for global variables were all assigned to the first emitted
compile unit in debug_info, regardless of what it was. Move them
instead to their respective compile units.

Change-Id: If794fa0ba4702f5b959c6e8c16119b16e7ecf6d8
Reviewed-on: https://go-review.googlesource.com/137235
Reviewed-by: Than McIntosh <thanm@google.com>
2018-09-27 11:58:35 +00:00