I thought that only non-static symbols need TOC, but apparently
this is not true. We need to use versioned .TOC. symbols.
Partially fix AIX build. There is still another problem, but this
gets us a bit farther in make.bash.
Change-Id: I40ba4a4dd27da0fc6ab26e4a54ff76bd2930aef1
Reviewed-on: https://go-review.googlesource.com/c/go/+/223379
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Use a different mechanism to access relocations from the object
files, and use it in the stack bounds check pass. This shows some
speedup.
(linking cmd/compile)
Dostkcheck 76.9ms ± 1% 55.1ms ± 1% -28.36% (p=0.008 n=5+5)
Change-Id: I2ac42da515dccd64719fb557ffff6cdc69e4319b
Reviewed-on: https://go-review.googlesource.com/c/go/+/222240
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
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>
dodata is a pile of dependencies on *Link. Pull some of these
dependencies out, and tighten up the visibility on the functions.
Change-Id: Id213f19ae7b63dd246ddb47b77ffde99f615aa80
Reviewed-on: https://go-review.googlesource.com/c/go/+/222061
Reviewed-by: Than McIntosh <thanm@google.com>
Implement a TODO in CL 220059, now that CL 220985 is in.
Change-Id: I7273a7b9e1e7c0b916780571c9c954da21366429
Reviewed-on: https://go-review.googlesource.com/c/go/+/222239
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
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>
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>
This CL converts the stack bound check pass to use the loader and
new symbol representation.
Change-Id: I0e4c102909db20dc2d5a367379146728862e53cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/220059
Reviewed-by: Than McIntosh <thanm@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>
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>
This CL implements windows version of -buildmode=pie code in both
cmd/go and cmd/link.
Windows executables built with -buildmode=pie set (unlike the one
built with -buildmode=exe) will have extra .reloc PE section, and
will have no IMAGE_FILE_RELOCS_STRIPPED flag set. They will also
have IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE flag set, and
IMAGE_DLLCHARACTERISTICS_HIGH_ENTROPY_VA flag set for windows/amd64.
Both cgo and non-cgo versions are implemented. And TestBuildmodePIE
is extended to test both cgo and non-cgo versions on windows and
linux.
This CL used some code from CLs 152759 and 203602.
RELNOTE=yes
Fixes#27144
Updates #35192
Change-Id: I1249e4ffbd79bd4277efefb56db321c390c0f76f
Reviewed-on: https://go-review.googlesource.com/c/go/+/214397
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The bootstrapping process (make.bash) on all other platforms use
internal linking. This change brings android/arm64 in line, fixing the
scary warning on our self-hosted Corellium builders:
warning: unable to find runtime/cgo.a
The linkmode default is changed to internal for all Android programs,
but in practice that won't matter outside our builders: using Go with
Android apps requires buildmode=c-shared which uses linkmode external.
Fixes#31343
Updates #31819
Change-Id: I3b3ada5ed69a7989e6d8e5960bbebf5e1c22aada
Reviewed-on: https://go-review.googlesource.com/c/go/+/207299
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
It was needed for the old softfloat implementation, which has
long gone.
Change-Id: Ib8d53689209a3b003d62f84c7c6047d8ec5df859
Reviewed-on: https://go-review.googlesource.com/c/go/+/220719
Reviewed-by: Than McIntosh <thanm@google.com>
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>
With unique global indices, MakeSymbolUpdater will not change the
symbol's index. So no need to return a new index.
Change-Id: I5b4fd6a0167cc74476880bbf4382c524ecde7721
Reviewed-on: https://go-review.googlesource.com/c/go/+/219227
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>
Currently, the loader adds defined package symbols and
non-package symbols to the global index space object by object.
This CL changes it to add all the defined package symbols first,
then all the non-package symbols. The advantage of doing this is
that when adding package symbols, by definition they cannot be
dup to each other, so we don't need to do a name lookup when
adding them.
We still add them to the lookup table (for now), since they may
still be referenced by name (e.g. through linkname). This CL is
also a prerequisite if we want to move to not adding package
symbols to the lookup table entirely (e.g. by using
pre-generated in-file lookup table).
Also update some comments to reflect the current state.
Change-Id: Ib757e070b48a9ef6215e47dc3421fc5c055b746c
Reviewed-on: https://go-review.googlesource.com/c/go/+/219078
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Now that we have local-global index mappings, just use that for
symbol reference resolution.
Change-Id: I6bc5405853fe040ff21b624ccd8da7965d66ec8c
Reviewed-on: https://go-review.googlesource.com/c/go/+/217065
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>
No real reason to keep the old code around as the new stuff is working
just fine.
Change-Id: I5e886f8274344738663a0ead181c5d58d9f5a45f
Reviewed-on: https://go-review.googlesource.com/c/go/+/215997
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Switch the linker's Link.linksetup method to work with loader.Sym
instead of sym.Symbols. Currently enabled when the new ELF host object
loader is turned on.
Change-Id: I336cc9f36166767baac574455531e195b6f1ac57
Reviewed-on: https://go-review.googlesource.com/c/go/+/213423
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>
This is a rewrite of the ELF host object loader to use just the Loader
interfaces for symbol creation, without constructing sym.Symbols. At
the moment this is gated under the temporary linker command line
option "-newldelf". This version is able to get through all.bash
on linux/amd64.
Change-Id: I99f41368f75b0df9e35ef3c2cf2a702b732540c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/210779
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Add SymbolBuilder helper type -- this type provides a set of methods
intended to make it easy to manipulate the content of a symbol (type,
relocations, data, etc).
Change-Id: I579bf8d04650e66d33a9780a6c2347a576c94c6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/210178
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Pushing the wavefront forward requires a single source of truth for
symbols. This CL removes sym.Symbols from the loader for host object
loaders, allowing us to have the single source of truth for symbols be
the loader, not some strange combination of sym.Symbols and the loader.
Change-Id: Ib8ff0117ebe6040fade346047535ff342d781081
Reviewed-on: https://go-review.googlesource.com/c/go/+/209217
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>
The NDK is switching to ldd, and will stop including the gold linker.
Change-Id: If74168017c9874134b34010906ab1d94001528b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/206840
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
There are more cleanups to do, but I want to keep this CL mostly
a pure deletion.
Change-Id: I30f4891a2ea54545fd6b83041746ab65895537e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/206558
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
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>
The -Wl,-headerpad, -Wl,-no_pie, -Wl,-pagezero_size flags are
incompatible with the bitcode-related flags used for iOS.
We already omitted the flags on darwin/arm and darwin/arm64; this change
omits the flags on all platforms != macOS so that building for the iOS
simulator works.
Updates #32963
Change-Id: Ic9af0daf01608f5ae0f70858e3045e399de7e95b
Reviewed-on: https://go-review.googlesource.com/c/go/+/205340
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
When linking a Go archive, if the archiver invocation is the very last
thing that needs to happen in the link (no "atexit" cleanups required
remove the locally created tmpdir) then call syscall.Exec to invoke
the archiver command instead of the usual exec.Command. This has the
effect of reducing peak memory use for the linker overall, since we
don't be holding onto all of the linker's live memory while the
archiver is running.
Change-Id: Ibbe22d8d67a70cc2a4f91c68aab56d19fb77c393
Reviewed-on: https://go-review.googlesource.com/c/go/+/203821
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
We used to pass -no_pie to external linker on darwin/arm, which
is incompatible with -fembed-bitcode. CL 201358 attempted to
remove the -no_pie flag, but it resulted the darwin linker to
complain about absolute addressing in TEXT segment.
On darwin/arm, we already get away from absolute addressing in
the TEXT section. The complained absolute addressing is in
RODATA, which was embedded in the TEXT segment. This CL moves
RODATA to the DATA segment, like what we already did on ARM64
and on AMD64 in c-archive/c-shared buildmodes for the same reason.
So there is no absolute addressing in the TEXT segment, which
allows us to remove -no_pie flag.
Fixes#35252.
Updates #32963.
Change-Id: Id6e3a594cb066d257d4f58fadb4a3ee4672529f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/205060
Reviewed-by: Elias Naur <mail@eliasnaur.com>
Currently in the linker we load internal packges first, then the
main package, and then load imported packages following the
dependency graph. As a result, packages are loaded mostly in the
dependency order, except the internal packages. The global symbol
indices are assigned the same way.
By loading the internal packages at the end, the packages are
loaded in the dependency order, so are the global indices. This
way, a relocation edge is mostly either within a packge or a
forward edge from a smaller index to a larger one. This allows
us to use a min-heap work queue in the deadcode pass, to achieve
better spatial locality (in the next CL).
Change-Id: I01fa9b3cf0c9e9e66006040f6378a51fd78f0f39
Reviewed-on: https://go-review.googlesource.com/c/go/+/204437
Reviewed-by: Jeremy Faller <jeremy@golang.org>
In newobj mode, cgo attributes are typically set later, as we
create sym.Symbols later. But when internal cgo linking, the
host object loaders still work with sym.Symbols, and the cgo
attributes need to be set for them to work properly. Therefore,
set them early. This will cause creating some Symbols eagerly,
but they are mostly host object symbols and will need to be
created anyway.
Now all cgo internal linking tests pass on ELF systems.
Change-Id: I023a4df4429acc8ebf5e185f62e6809198497a78
Reviewed-on: https://go-review.googlesource.com/c/go/+/204857
Reviewed-by: Than McIntosh <thanm@google.com>
