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>
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
Flip back to the old object files for Go 1.14.
Change-Id: I4ad499460fb7156b63fc63e9c6ea4f7099e20af2
Reviewed-on: https://go-review.googlesource.com/c/go/+/204098
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@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>
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>
Switch the default to new object files.
Internal linking cgo is disabled for now, as it does not work yet
in newobj mode.
Shared libraries are also broken.
Disable some tests that are known broken for now.
Change-Id: I8ca74793423861d607a2aa7b0d89a4f4d4ca7671
Reviewed-on: https://go-review.googlesource.com/c/go/+/200161
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
If the new object file format is used, now we load full symbol
contents after the deadcode pass, for reachable symbols only.
We still load some informations early, like relocations and the
contents of type symbols, which are used in the deadcode pass.
If we rewrite deadcode to use index directly, we could delay more
of the loading (to sym.Symbol), and perhaps delay the creation of
sym.Symbol.
TODO: internal linking with host objects doesn't work yet.
Change-Id: I7d4880e8f150e8709ffac277e62191623440e4cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/197258
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This is in preparation of delaying loading symbol content to
after dead code elimination.
Change-Id: Ia4ce82d9a42cc1a76c82f6d0eb9a54b0325ee3ba
Reviewed-on: https://go-review.googlesource.com/c/go/+/197061
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Parse new object file format in the linker. At least we can link
a hello-world program.
Add a basic "loader", which handles symbol references in the
object file.
- mapping between local and global indices
- resolve by-name references
(TODO: the overwrite logic isn't implemented yet)
Currently we still create sym.Symbol rather early, and, after all
the object files are loaded and indexed references are resolved,
add all symbols to sym.Symbols.
The code here is probably not going in the final version. This
is basically only for debugging purposes -- to make sure the
writer and the reader work as expected.
Change-Id: I895aeea68326fabdb7e5aa1371b8cac7211a09dd
Reviewed-on: https://go-review.googlesource.com/c/go/+/196032
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
compilebench depends on the legacy heap profile format to read the
allocation stats of build tools. We're adding a benchmark for the
linker to compilebench, so we need the linker to emit the heap profile
in the legacy format.
This is the linker equivalent of CL 35484, which did this for the
compiler.
Change-Id: I16ad60c4f0fd80b4b6d608a5677ebe04e1fb5e5a
Reviewed-on: https://go-review.googlesource.com/c/go/+/176057
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
It is useful to be able to dig the Go version out of a binary,
even a stripped binary. rsc.io/goversion does this for x86
binaries by disassembling the binary to find runtime/proc.go's
startup-time reference to runtime.buildVersion's address.
That approach is quite fragile: the implementation doesn't
work for non-x86 and must be updated as the generated
code changes.
rsc.io/goversion finds the module version string by looking
for random 16-byte framing around the actual string.
This is less fragile but fairly kludgy and requires scanning
the entire data segment.
cmd/buildid finds the build ID by looking for an ELF note
or else falling back to scanning the beginning of the text
segment for a magic string. This has proved quite reliable
and doesn't require scanning much of the binary.
This CL makes it possible to find the Go and module versions
using a scan more like the build ID scan: a symbol early in
the writable data segment starts with a magic number and
then has pointers to the two string variables.
Setting up for "go version <binary>".
For #31624.
Change-Id: I78ea8c52fe1686b5cc5a829ca5f198104d10ebf0
Reviewed-on: https://go-review.googlesource.com/c/go/+/173342
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Move the phase of applying relocations later, after the sections
and segments are written to the mmap'd output region. Then apply
relocations directly in the output region, instead of the input.
So the input slices we read in don't need to be modified.
This is in preparation for mmap'ing input files read-only.
Change-Id: If9c80657b4469da36aec5a9ab6acf664f5af8fa0
Reviewed-on: https://go-review.googlesource.com/c/go/+/170739
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
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>
Use mmap for writing most of the output file content,
specifically, the sections and segments. After layout, we
already know the sizes and file offsets for the sections and
segments. So we can just write the bytes by copying to a mmap'd
backing store.
The writing of the output file is split into two parts. The first
part writes the sections and segments to the mmap'd region. The
second part writes some extra content, for which we don't know
the size, so we use direct file IO.
This is in preparation for mmap'ing input files read-only.
Change-Id: I9f3b4616a9f96bfd5c940d74c50aacd6d330f7d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/170738
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
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>
Introduce a new linker command line option "-strictdups", which
enables sanity checking of "ok to duplicate" symbols, especially
DWARF info symbols. Acceptable values are 0 (no checking) 1 (issue
warnings) and 2 (issue a fatal error checks fail).
Currently if we read a DWARF symbol (such as "go.info.PKG.FUNCTION")
from one object file, and then encounter the same symbol later on
while reading another object file, we simply discard the second one
and move on with the link, since the two should in theory be
identical.
If as a result of a compiler bug we wind up with symbols that are not
identical, this tends to (silently) result in incorrect DWARF
generation, which may or may not be discovered depending on who is
consuming the DWARF and what's being done with it.
When this option is turned on, at the point where a duplicate
symbol is detected in the object file reader, we check to make sure
that the length/contents of the symbol are the same as the previously
read symbol, and print a descriptive warning (or error) if not.
For the time being this can be used for one-off testing to find
problems; at some point it would be nice if we can enable it by
default.
Updates #30908.
Change-Id: I64c4e07c326b4572db674ff17c93307e2eec607c
Reviewed-on: https://go-review.googlesource.com/c/go/+/168410
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
FlagDataAddr is a vestige from git commit 0cafb9e (2008;
no Gerrit CL number).
It was never used but unfortunately setting it would
cause a spurious warning:
warning: -D<value> is ignored because of -R0x1000
yet if -R was unset e.g. -R=0, the linker would crash
with a divide by zero runtime panic.
Fixes#28921
Change-Id: Ia910399bc269337a9a860f3a26cd48fae6e62724
Reviewed-on: https://go-review.googlesource.com/c/151021
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit adds AIX operating system to cmd/link package for ppc64
architecture.
Updates: #25893
Change-Id: I349e0a2658c31919b72117b62c4c9935c9af07c0
Reviewed-on: https://go-review.googlesource.com/c/138730
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
.rel symbol type is sym.SELFROSECT, and that makes .rel written
into .rdata section. But .rel stores code - jump table used for
external C functions. So we have to mark whole .rdata section
as executable (IMAGE_SCN_MEM_EXECUTE), because of .rel presence
in it.
Move .rel into .text section, and make .rdata section non executable.
I also had to move code that adjusted the size of .rel symbol
before calling textaddress, otherwise textaddress would not
calculate size of .text section correctly.
Fixes#25926
Change-Id: I4962f5de7b367410154c8709adfcd8472de9ac1a
Reviewed-on: https://go-review.googlesource.com/c/125455
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Splits part of dwarfgeneratedebugsyms into a new function,
dwarfGenerateDebugInfo which is called between deadcode elimination
and type name mangling.
This function takes care of collecting and processing the DIEs for
all functions and package-level variables and also generates DIEs
for all types used in the program.
Fixes#23733
Change-Id: I75ef0608fbed2dffc3be7a477f1b03e7e740ec61
Reviewed-on: https://go-review.googlesource.com/111237
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Moves type name mangling after deadcode elimination. The motivation for
doing this is to create a space between deadcode elimination and type name
mangling where DWARF generation for types and variables can exist, to fix
issue #23733.
Change-Id: I9db8ecc0f4efe3df6c1e4025f02642fd452f9a39
Reviewed-on: https://go-review.googlesource.com/111236
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The sym.Symbol 'Reachparent' field is used only when field tracking
is enabled. So as to use less memory for the common case where
field tracking is not enabled, remove this field and use a side
table stored in the context to achieve the same functionality.
Updates #26186
Change-Id: Idc5f8b0aa323689d4d51dddb5d1b0341a37bb7d2
Reviewed-on: https://go-review.googlesource.com/121915
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We want to compress DWARF even on macOS, but the native toolchain isn't
going to understand it. Add a flag that can be used to disable
compression, then add Darwin to the whitelist used during internal
linking.
Unlike GNU ld, the Darwin linker doesn't have a handy linker flag to do
compression. But since we're already doing surgery to put the DWARF in
the output executable in the first place, compressing it at the same
time isn't unduly difficult. This does have the slightly odd effect of
compressing some Apple proprietary debug sections, which absolutely
nothing will understand. Leaving them uncompressed didn't make much
sense, though, since I doubt they're useful without (say) __debug_info.
Updates #11799
Change-Id: Ie00b0215c630a798c59d009a641e2d13f0e7ea01
Reviewed-on: https://go-review.googlesource.com/120155
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Forked from CL 111895.
The trickiest part of this is that the binary layout code (blk,
elfshbits, and various other things) assumes a constant offset between
symbols' and sections' file locations and their virtual addresses.
Compression, of course, breaks this constant offset. But we need to
assign virtual addresses to everything before compression in order to
resolve relocations before compression. As a result, compression needs
to re-compute the "address" of the DWARF sections and symbols based on
their compressed size. Luckily, these are at the end of the file, so
this doesn't perturb any other sections or symbols. (And there is, of
course, a surprising amount of code that assumes the DWARF segment
comes last, so what's one more place?)
Relevant benchmarks:
name old time/op new time/op delta
StdCmd 10.3s ± 2% 10.8s ± 1% +5.43% (p=0.000 n=30+30)
name old text-bytes new text-bytes delta
HelloSize 746kB ± 0% 746kB ± 0% ~ (all equal)
CmdGoSize 8.41MB ± 0% 8.41MB ± 0% ~ (all equal)
[Geo mean] 2.50MB 2.50MB +0.00%
name old data-bytes new data-bytes delta
HelloSize 10.6kB ± 0% 10.6kB ± 0% ~ (all equal)
CmdGoSize 252kB ± 0% 252kB ± 0% ~ (all equal)
[Geo mean] 51.5kB 51.5kB +0.00%
name old bss-bytes new bss-bytes delta
HelloSize 125kB ± 0% 125kB ± 0% ~ (all equal)
CmdGoSize 145kB ± 0% 145kB ± 0% ~ (all equal)
[Geo mean] 135kB 135kB +0.00%
name old exe-bytes new exe-bytes delta
HelloSize 1.60MB ± 0% 1.05MB ± 0% -34.39% (p=0.000 n=30+30)
CmdGoSize 16.5MB ± 0% 11.3MB ± 0% -31.76% (p=0.000 n=30+30)
[Geo mean] 5.14MB 3.44MB -33.08%
Fixes#11799.
Updates #6853.
Change-Id: I64197afe4c01a237523a943088051ee056331c6f
Reviewed-on: https://go-review.googlesource.com/118276
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently these two forms of layout are done in a single pass. This
makes it difficult to compress DWARF sections because that must be
done after relocations are applied, which must happen after virtual
address layout, but we can't layout the file until we've compressed
the DWARF sections.
Fix this by separating the two layout steps. In the process, we can
also unify the copy-pasted code in Link.address to compute file
offsets, which currently has some unnecessary variation.
Unlike the current file offset computation, which depends on virtual
addresses, the new computation only uses file offsets and sizes. This
will let us compress the file representation of a segment and create
the file layout based on its on-disk size rather than its original
in-memory size.
Tested by comparing the test binary for the "strings" package on all
supported GOOS/GOARCH combinations. All binaries are identical
(except, of course, their build IDs).
This is a second attempt at CL 111682.
For #11799.
Fixes#25863.
Change-Id: If09f28771bb4d78dd392fd58b8d7c9d5f22b0b9e
Reviewed-on: https://go-review.googlesource.com/118716
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently these two forms of layout are done in a single pass. This
makes it difficult to compress DWARF sections because that must be
done after relocations are applied, which must happen after virtual
address layout, but we can't layout the file until we've compressed
the DWARF sections.
Fix this by separating the two layout steps. In the process, we can
also unify the copy-pasted code in Link.address to compute file
offsets. Currently, each instance of this is slightly different, but
there's no reason for it to be. For example, we don't perform
PEFILEALIGN alignment on Segrodata or Selreltodata even when HeadType
== Hwindows, but it turns out it doesn't matter whether you do or
don't because these segments simply don't exist on Windows. Hence, in
the unified code path, we do this alignment for all segments.
Likewise, there are two ways of computing Fileoff:
seg.Vaddr - prev.Vaddr + prev.Fileoff
and
prev.Fileoff + uint64(Rnd(int64(prev.Filelen), int64(*FlagRound)))
At the moment, these always have the same value, but the latter will
continue to work after we start compressing sections on disk.
Tested by comparing test binaries for all packages in std before and
after this change for GOOS={linux,windows,darwin,plan9}. All binaries
are identical.
For #11799.
Change-Id: If09f28771bb4d78dd392fd58b8d7c9d5f22b0b9f
Reviewed-on: https://go-review.googlesource.com/111682
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If go toolchain is not built with GOEXPERIMENT=fieldtrack,
skip fieldtrack pass in the linker as it does full symtab traversal.
For linking "hello world" example from net/http:
name old time/op new time/op delta
Linker-4 530ms ± 2% 525ms ± 2% -1.03% (p=0.028 n=17+19)
Fixes#20318
Updates #14624
Change-Id: I99336513db77d13f95f47d27339d76f01c42a5da
Reviewed-on: https://go-review.googlesource.com/113635
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
s/Thearch/thearch/
This reduces the amount of exported global variables,
which in turn could make it easier to refactor them later.
Also updated somewhat vague comment about ld.Thearch.
There is no need for Thearch to be exported as Archinit is
called by ld.Main.
Updates #22095
Change-Id: I266b291f6eac0165f70c51964738206e066cea08
Reviewed-on: https://go-review.googlesource.com/103878
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Suppose you build the Go toolchain in directory A,
move the whole thing to directory B, and then use
it from B to build a new program hello.exe, and then
run hello.exe, and hello.exe crashes with a stack
trace into the standard library.
Long ago, you'd have seen hello.exe print file names
in the A directory tree, even though the files had moved
to the B directory tree. About two years ago we changed
the compiler to write down these files with the name
"$GOROOT" (that literal string) instead of A, so that the
final link from B could replace "$GOROOT" with B,
so that hello.exe's crash would show the correct source
file paths in the stack trace. (golang.org/cl/18200)
Now suppose that you do the same thing but hello.exe
doesn't crash: it prints fmt.Println(runtime.GOROOT()).
And you run hello.exe after clearing $GOROOT from the
environment.
Long ago, you'd have seen hello.exe print A instead of B.
Before this CL, you'd still see hello.exe print A instead of B.
This case is the one instance where a moved toolchain
still divulges its origin. Not anymore. After this CL, hello.exe
will print B, because the linker sets runtime/internal/sys.DefaultGoroot
with the effective GOROOT from link time.
This makes the default result of runtime.GOROOT once again
match the file names recorded in the binary, after two years
of divergence.
With that cleared up, we can reintroduce GOROOT into the
link action ID and also reenable TestExecutableGOROOT/RelocatedExe.
When $GOROOT_FINAL is set during link, it is used
in preference to $GOROOT, as always, but it was easier
to explain the behavior above without introducing that
complication.
Fixes#22155.
Fixes#20284.
Fixes#22475.
Change-Id: Ifdaeb77fd4678fdb337cf59ee25b2cd873ec1016
Reviewed-on: https://go-review.googlesource.com/86835
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The linker has been applying -X options before loading symbols,
meaning that when it sees -X y=z it creates a symbol named y
and initializes its string data to z. The symbol named y is marked
"DUPOK" so that when the actual packages are loaded, no error is
emitted when the real y is seen. The predefined y's data is used
instead of whatever the real y says.
If we define -X y=z and we never load y, then the predefined symbol
is dropped during dead code elimination, but not in shared library
builds. Shared library builds must include all symbols, so we have to
be more careful about not defining symbols that wouldn't have
appeared anyway.
To be more careful, save the -X settings until after all the symbols
are loaded from the packages, and then apply the string changes
to whatever symbols are known (but ignore the ones that were not
loaded at all). This ends up being simpler anyway, since it doesn't
depend on DUPOK magic.
Makes CL 86835 safe.
Fixes#23273.
Change-Id: Ib4c9b2d5eafa97c5a8114401dbec0134c76be54f
Reviewed-on: https://go-review.googlesource.com/86915
Run-TryBot: Russ Cox <rsc@golang.org>
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For #22095
Change-Id: Idcfdfe8a94db8626392658bb93429454238f648a
Reviewed-on: https://go-review.googlesource.com/70835
Run-TryBot: David Crawshaw <crawshaw@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #22095
Change-Id: Iba3dffc782cecc15ea0e90a971a2734729984945
Reviewed-on: https://go-review.googlesource.com/70834
Run-TryBot: David Crawshaw <crawshaw@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
Also add -V=full to print a unique identifier of the specific tool being invoked.
This will be used for content-based staleness.
Also sort and clean up a few of the flag doc comments.
Change-Id: I786fe50be0b8e5f77af809d8d2dab721185c2abd
Reviewed-on: https://go-review.googlesource.com/68590
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
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>
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For #22095
Change-Id: I9d1f0d93f8fd701a24af826dc903eea2bc235de2
Reviewed-on: https://go-review.googlesource.com/67317
Run-TryBot: David Crawshaw <crawshaw@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
Adds the ability to specify the file location of each imported package,
like in the -importcfg added to cmd/compile in a related CL.
In effect, -importcfg is a generalization of and supersedes -installsuffix
and -L. Of course, those flags will continue to be supported, for
compatibility with other tools.
Having this flag in Go 1.9 will let us try some experiments involving
package management without needing guinea pigs to build a custom
Go toolchain.
This flag also helps with #14271 at some later point.
For #20579.
Change-Id: Ie4c171bcd3aa2faa446ac340e36516f2f9853882
Reviewed-on: https://go-review.googlesource.com/44851
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
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Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
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>
cmd/link -H flag is stored in variable of type
cmd/internal/obj.HeadType. The HeadType type from cmd/internal/obj
accepts Hwindows and Hwindowsgui values, but these values have
same meaning - build PE executable, except for 2 places in
cmd/link/internal/ld package.
This CL introduces code to store cmd/link "windowsgui" -H flag
in cmd/link/internal/ld, so cmd/internal/obj.Hwindowsgui can be
removed in the next CL.
This CL also includes 2 changes to code where distinction
between Hwindows and Hwindowsgui is important.
Change-Id: Ie5ee1f374e50c834652a037f2770118d56c21a2a
Reviewed-on: https://go-review.googlesource.com/38760
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Plumb the import path of a plugin package through to the linker, and
use it as the prefix on the exported symbol names.
Before this we used the basename of the plugin file as the prefix,
which could conflict and result in multiple loaded plugins sharing
symbols that are distinct.
Fixes#17155Fixes#17579
Change-Id: I7ce966ca82d04e8507c0bcb8ea4ad946809b1ef5
Reviewed-on: https://go-review.googlesource.com/32355
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Instead of generating typelink symbols in the compiler
mark types that should have typelinks with a flag.
The linker detects this flag and adds the marked types
to the typelink table.
name old s/op new s/op delta
LinkCmdCompile 0.27 ± 6% 0.25 ± 6% -6.93% (p=0.000 n=97+98)
LinkCmdGo 0.30 ± 5% 0.29 ±10% -4.22% (p=0.000 n=97+99)
name old MaxRSS new MaxRSS delta
LinkCmdCompile 112k ± 3% 106k ± 2% -4.85% (p=0.000 n=100+100)
LinkCmdGo 107k ± 3% 103k ± 3% -3.00% (p=0.000 n=100+100)
Change-Id: Ic95dd4b0101e90c1fa262c9c6c03a2028d6b3623
Reviewed-on: https://go-review.googlesource.com/31772
Run-TryBot: Shahar Kohanim <skohanim@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
ARM direct CALL/JMP instruction has 24 bit offset, which can only
encodes jumps within +/-32M. When the target is too far, the top
bits get truncated and the program jumps wild.
This CL detects too-far jumps and automatically insert trampolines,
currently only internal linking on ARM.
It is necessary to make the following changes to the linker:
- Resolve direct jump relocs when assigning addresses to functions.
this allows trampoline insertion without moving all code that
already laid down.
- Lay down packages in dependency order, so that when resolving a
inter-package direct jump reloc, the target address is already
known. Intra-package jumps are assumed never too far.
- a linker flag -debugtramp is added for debugging trampolines:
"-debugtramp=1 -v" prints trampoline debug message
"-debugtramp=2" forces all inter-package jump to use
trampolines (currently ARM only)
"-debugtramp=2 -v" does both
- Some data structures are changed for bookkeeping.
On ARM, pseudo DIV/DIVU/MOD/MODU instructions now clobber R8
(unfortunate). In the standard library there is no ARM assembly
code that uses these instructions, and the compiler no longer emits
them (CL 29390).
all.bash passes with -debugtramp=2, except a disassembly test (this
is unavoidable as we changed the instruction).
TBD: debug info of trampolines?
Fixes#17028.
Change-Id: Idcce347ea7e0af77c4079041a160b2f6e114b474
Reviewed-on: https://go-review.googlesource.com/29397
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This CL gives Linkmode a type, switches it to the standard flag
handling mechanism, and deduplicates some logic.
There is a semantic change in this CL. Previously if a link was
invoked explicitly with -linkmode=internal, any condition that forced
external linking would silently override this and use external
linking. Instead it now fails with a reason why. I believe this is an
improvement, but will change it back if there's disagreement.
Fixes#12848
Change-Id: Ic80e341fff65ecfdd2b6fdd6079674cc7210fc5f
Reviewed-on: https://go-review.googlesource.com/28971
Run-TryBot: David Crawshaw <crawshaw@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
This CL contains several linker changes to support creating plugins.
It collects the exported plugin symbols provided by the compiler and
includes them in the moduledata.
It treats a binary as being dynamically linked if it imports the plugin
package. This lets the dynamic linker de-duplicate symbols.
Change-Id: I099b6f38dda26306eba5c41dbe7862f5a5918d95
Reviewed-on: https://go-review.googlesource.com/27820
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
As cmd/internal/obj is coordinating the definition of GOOS, GOARCH,
etc across the compiler and linker, turn its functions into globals
and use them everywhere.
Change-Id: I5db5addda3c6b6435c37fd5581c7c3d9a561f492
Reviewed-on: https://go-review.googlesource.com/28854
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
