Move more items into the dodata state object (including the "datsize"
variable used in allocateSections) and the Link ctxt pointer), so as
to prepare for follow-on refactorings. No change in functionality.
Change-Id: Ie2b1651c1ac9b89deb3f7692227dcd931240afa9
Reviewed-on: https://go-review.googlesource.com/c/go/+/228779
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>
Recreation of CL 228317.
The problem with that original CL was a late requested change,
reordering reloc and asmb, resulting in symbols having stale pointers to
their data. I've fixed this by preallocating the heap variable in OutBuf
for platforms w/o mmap.
Change-Id: Icdb392ac2c8d6518830f4c84cf422e78b8ab68c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/228782
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Begin refactoring dodata to try to convert it from a single giant blob
to something more hierarchical, with descriptive function names for
sub-parts.
Add a state object to hold things like "data" and "dataMaxAlign"
arrays that are used throughout dodata. Extract out the code that
allocates data symbols to sections into a separate method (this
method is still too big, probably needs to be refactored again).
No change in functionality.
Change-Id: I7b52dc2aff0356e7d4b5d6f629d907fd37d3082c
Reviewed-on: https://go-review.googlesource.com/c/go/+/228259
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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>
lib.Textp was used for text address assignment and trampoline
insertion. Now that it has been converted to using the loader,
no need to populate lib.Textp.
Port the logic of canonicalizing dupok symbol's package to the
loader.
unit.Textp was used for DWARF generation, which has also been
converted to using the loader.
Change-Id: I22d4dd30a52a29dd5b1b7b795d43a19f6215e4ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/228140
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
We split the output into blocks and write them in parallel. The
block boundary is placed at symbol boundary. In the case of outer
symbols and sub symbols, currently we may split an outer symbol
into two blocks. This will be bad, as the two blocks will have
overlapping address range, since outer symbol and its sub symbols
occupies the same address range.
Make sure we place block boundary only at top-level symbol
boundaries.
Fix boringcrypto build.
Change-Id: I56811d3969c65c6be97672d8e1f1ea36b2447465
Reviewed-on: https://go-review.googlesource.com/c/go/+/227957
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Don't emit an error for undefined symbol in trampoline
generation pass, which will be duplicate as we'll emit a better
one later.
Fix TestUndefinedRelocErrors on PPC64.
Change-Id: I964d4bd63ec4b4c6eb5d98caf68db93ce6488bf5
Reviewed-on: https://go-review.googlesource.com/c/go/+/227617
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Implement text address assignment and trampoline generation using
the loader.
Note: the trampoline insertion part doesn't actually work. It
also needs to propagate Aux symbols for external symbols in
LoadFull. But it won't be needed after converting pclntab
generation, so I'll leave it out for now. This could break
linking large binaries on PPC64 and ARM.
Change-Id: Ie46a35b25d7c027983dd877207cfa8f67c32530b
Reviewed-on: https://go-review.googlesource.com/c/go/+/227482
Reviewed-by: Than McIntosh <thanm@google.com>
This ports CL 226997 to the dev.link branch.
- The assembler part and old object file writing are unchanged.
- Changes to cmd/link are applied to cmd/oldlink.
- Add alignment field to new object files for the new linker.
Change-Id: Id00f323ae5bdd86b2709a702ee28bcaa9ba962f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/227025
Reviewed-by: Than McIntosh <thanm@google.com>
Make sure we never overrun the end address.
Should fix AIX build.
Change-Id: I9926387d4512ec8b4acc32b7f32cee2b2aca25b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/226718
Reviewed-by: Jeremy Faller <jeremy@golang.org>
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>
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>
Make sure we write the entire address range we are asked to write,
with no holes between the blocks or at the end.
Should fix NetBSD build.
Change-Id: I13b1f551377cbc4bcde3650417ac95cba62ff807
Reviewed-on: https://go-review.googlesource.com/c/go/+/226617
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Introduces a parallel OutBuf implementation, and POC on amd64. Due to
some of the weird behaviors I saw on MacOS (SIGBUS while calling msync),
I will wait for feedback to port to other architectures.
On my mac, sped up Asmb by ~78% for cmd/compile (below). Will likely
have an appreciable speedup on kubelet benchmark.
Asmb 39.1ms ±11% 8.5ms ±10% -78.17% (p=0.000 n=10+9)
TotalTime 596ms ± 2% 577ms ± 8% -3.07% (p=0.034 n=8+10)
Change-Id: Id2a2577c3f4da155d8dccc862897f43b941877ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/223742
Run-TryBot: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
On Solaris, in the runtime it defines the external name of
runtime.etext as _etext (runtime/os3_solaris.go:13). In CL 224939
we changed to put external names in the ELF symbol table more
consistently. In this case it will contain _etext but not
runtime.etext.
To be conservative, this CL defines both runtime.etext and _text
in the linker.
Change-Id: I79f196e87b655042be97b0fbbab02d0ebc8db2fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/225537
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
The lookup is only used for DWARF section symbols, for which we
can just link the symbols to the sections.
Change-Id: Id8426fbf59bab2528f57e28e2043e0b405656a9f
Reviewed-on: https://go-review.googlesource.com/c/go/+/225204
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
It is needed in Xcoffadddynrel. And it will be needed once we
move more things to new style (the sym.Symbol parameters will
also need to change).
Change-Id: Ie12683f9b44e21f1e6ea711bf2f4c5c32282e5b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/225203
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This change moves datap from global space into the link context. Rather
than having it exist in context, we could have it returned from dodata,
and pass it as a parameter, but it is used in awkward places in the
Arch functions. Easiest for now is just keeping it in the context, until
we more formally move it to slices of loader.Sym.
This is a largely non-functional change.
Change-Id: Ica93bd857c39913ad470a61c63bc8d21704d6308
Reviewed-on: https://go-review.googlesource.com/c/go/+/222664
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This is a non-functional change, just moving things around, making
dodata a more approachable piece of code.
Change-Id: I06fa047cbef2313040a31998fa8d242ccb2fedea
Reviewed-on: https://go-review.googlesource.com/c/go/+/222662
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
If the variable is not reachable, don't bother setting it.
The old behavior was to set it but not mark it reachable, nor the
string data it points to. This was changed in CL 219226, which
changed the variable and the string data to always reachable.
Typically it shouldn't matter much besides some waste of binary
size. But it does matter on AIX (crash in make.bash). I haven't
looked into why.
Fix AIX build.
Change-Id: I546a0c94ad77b10485ceb66e1288a408e2a2a3e2
Reviewed-on: https://go-review.googlesource.com/c/go/+/223380
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>
I tried a couple of different architectures (goroutine per symbol, 8
goroutines handling symbols from channels, and this architecture), and
this was the best. Another possible approach could be to divide up the
space of relocations, forgo the channels, and just pass slices to the
relocation routines, which would possibly be faster.
Reloc 13.9ms ± 5% 9.0ms ±10% -35.09% (p=0.000 n=8+9)
Change-Id: I5111220e855313fae4b89d64277759c4dc33b697
Reviewed-on: https://go-review.googlesource.com/c/go/+/220842
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This is the last step requried before relocsym can go parallel.
Change-Id: Id1c1c530c2b9277917208c3767eeb29e02c17a9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/220841
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Also correct a few places I hadn't switched over to Target from *Link
context.
Change-Id: I6de6b39723762de3fa5f8d12800085421aca76fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/220840
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
We need to propogate Target through the relocation functions.
Change-Id: I1192d54a20a34569fd13c1511d2b21ebf2d1272e
Reviewed-on: https://go-review.googlesource.com/c/go/+/220839
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
In an effort to make relocation application thread-safe remove another
dependence on context.
Change-Id: Ic53ea122cce72117fcebe56e386b710755f6eb68
Reviewed-on: https://go-review.googlesource.com/c/go/+/220838
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
In its current form, relocsym requires the Link context -- largely in a
readonly state. Rather than passing around such heavy-weight object to
the function, this CL separates out the link target. From here, the
number of touchpoints (and thread unsafe portions) of relocing symbols
can be mentally reasoned about.
(NB: My personal intent is to make this more universal -- passing only
the necessary variables/state to reloc functions. This is a taste to see
if we like this form.)
Change-Id: Id9177d03267fedf0bb572a9d61bc07b64309c3b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/220837
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Otherwise we leave a gap at the start of Segrelrodata equal to the
size of the read-only non-relro data, which causes -buildmode=pie
executables to be noticeably larger than -buildmode=exe executables.
Change-Id: I98956ef29d5b7a57ad8e633c823ac09d9ca36a45
Reviewed-on: https://go-review.googlesource.com/c/go/+/208897
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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>
Factor out the direct CALL identification code from objabi.IsDirectJump and
use this in two places that have separately maintained lists of reloc types.
Provide an objabi.IsDirectCallOrJump function that implements the original
behaviour of objabi.IsDirectJump.
Change-Id: I48131bae92b2938fd7822110d53df0b4ffb35766
Reviewed-on: https://go-review.googlesource.com/c/go/+/196577
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
In the dev.link branch we implemented the new object file format
and (part of) the linker improvements described in
https://golang.org/s/better-linker
The new object file is index-based and provides random access.
The linker maps the object files into read-only memory, and
access symbols on-demand using indices, as opposed to reading
all object files sequentially into the heap with the old format.
The linker carries symbol informations using indices (as opposed
to Symbol data structure). Symbols are created after the
reachability analysis, and only created for reachable symbols.
This reduces the linker's memory usage.
Linking cmd/compile, it creates ~25% fewer Symbols, and reduces
memory usage (inuse_space) by ~15%. (More results from Than.)
Currently, both the old and new object file formats are supported.
The old format is used by default. The new format can be turned
on by using the compiler/assembler/linker's -newobj flag. Note
that the flag needs to be specified consistently to all
compilations, i.e.
go build -gcflags=all=-newobj -asmflags=all=-newobj -ldflags=-newobj
Change-Id: Ia0e35306b5b9b5b19fdc7fa7c602d4ce36fa6abd
This CL adds experimental coverage instrumentation similar to what
github.com/dvyukov/go-fuzz produces in its -libfuzzer mode. The
coverage can be enabled by compiling with -d=libfuzzer. It's intended
to be used in conjunction with -buildmode=c-archive to produce an ELF
archive (.a) file that can be linked with libFuzzer. See #14565 for
example usage.
The coverage generates a unique 8-bit counter for each basic block in
the original source code, and emits an increment operation. These
counters are then collected into the __libfuzzer_extra_counters ELF
section for use by libFuzzer.
Updates #14565.
Change-Id: I239758cc0ceb9ca1220f2d9d3d23b9e761db9bf1
Reviewed-on: https://go-review.googlesource.com/c/go/+/202117
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
R_ADDRCUOFF refers to the offset from the start of the
compilation unit. Now that we could have multiple compilation
units per package, we should use the start of the compilation
unit, instead of the start of the package.
Change-Id: I3d6a3c5a5c47c9ccf88091ed05413ced826f9934
Reviewed-on: https://go-review.googlesource.com/c/go/+/204828
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Allows Go asm calls referencing a function in a .syso file to be
passed through to the external linker, that would have otherwise
raised a "relocation target X not defined" error in cmd/link.
Fixes#33139
Change-Id: I2a8eb6063ebcd05fac96f141acf7652cf9189766
Reviewed-on: https://go-review.googlesource.com/c/go/+/198798
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
This is part two if the nacl removal. Part 1 was CL 199499.
This CL removes amd64p32 support, which might be useful in the future
if we implement the x32 ABI. It also removes the nacl bits in the
toolchain, and some remaining nacl bits.
Updates #30439
Change-Id: I2475d5bb066d1b474e00e40d95b520e7c2e286e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/200077
Reviewed-by: Ian Lance Taylor <iant@golang.org>
