When plugin is used, we already mark all exported methods
reachable. However, when the plugin and the host program share
a common package, an unexported method could also be reachable
from both the plugin and the host via interfaces. We need to mark
them as well.
Fixes#51621.
Change-Id: I1a70d3f96b66b803f2d0ab14d00ed0df276ea500
Reviewed-on: https://go-review.googlesource.com/c/go/+/393365
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
When building/using plugins on darwin, we need to use flat
namespace so the same symbol from the main executable and the
plugin can be resolved to the same address. Apparently, when using
flat namespace the dynamic linker can hang at forkExec when
resolving a lazy binding. Work around it by forcing early bindings.
Fixes#38824.
Change-Id: I983aa0a0960b15bf3f7871382e8231ee244655f4
Reviewed-on: https://go-review.googlesource.com/c/go/+/372798
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Though this was a problem for Go 1.17,
it appears not to be a problem on tip.
This reverts change made in CL 321349.
For #46239.
Change-Id: Ie4d6649fbabce3bb2c1cf04d97760ba6ceadaca5
Reviewed-on: https://go-review.googlesource.com/c/go/+/369752
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
This test is known to be broken on the darwin/arm64 builder.
Skip it while it's being investigated so it doesn't mask other failures.
For #46239.
Updates #43228.
Change-Id: I8fe57a0636bba84c3100337146dcb96cc264e524
Reviewed-on: https://go-review.googlesource.com/c/go/+/321349
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Some uses of crosscall2 did not work on ppc64le and probably
aix-ppc64. In particular, if there was a main program compiled
with -buildmode=pie and used a plugin which invoked crosscall2,
then failures could occur due to R2 getting set incorrectly along the
way. The problem was due to R2 being saved on the caller's
stack; it is now saved on the crosscall2 stack. More details can be
found in the issue.
This adds a testcase where the main program is built with pie
and the plugin invokes crosscall2.
This also changes the save of the CR bits from MOVD to MOVW as
it should be.
Fixes#43228
Change-Id: Ib5673e25a2ec5ee46bf9a1ffb0cb1f3ef5449086
Reviewed-on: https://go-review.googlesource.com/c/go/+/319489
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Heschi Kreinick <heschi@google.com>
tests that run commands should log their actions in a
shell-pasteable way.
Change-Id: Ifeee88397047ef5a76925c5f30c213e83e535038
Reviewed-on: https://go-review.googlesource.com/c/go/+/309770
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Update references missed in CL 263142.
For #41190
Change-Id: I778760a6a69bd0440fec0848bdef539c9ccb4ee1
GitHub-Last-Rev: dda42b09ff
GitHub-Pull-Request: golang/go#42874
Reviewed-on: https://go-review.googlesource.com/c/go/+/273946
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Zhang <cherryyz@google.com>
Static tmps are private to a package, but with plugins a package
can be shared among multiple DSOs. They need to have a consistent
view of the static tmps, especially for writable ones. So export
them. (Read-only static tmps have the same values anyway, so it
doesn't matter. Also Mach-O doesn't support dynamically exporting
read-only symbols anyway.)
Fixes#44956.
Change-Id: I921e25b7ab73cd5d5347800eccdb7931e3448779
Reviewed-on: https://go-review.googlesource.com/c/go/+/301793
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
When using plugins, a type (whose value) may be pass to a plugin
and get converted to interface there, or vice versa. We need to
treat the type as potentially converted to interface, and retain
its methods.
Should fix#44586.
Change-Id: I80dd35e68baedaa852a317543ccd78d94628d13b
Reviewed-on: https://go-review.googlesource.com/c/go/+/296709
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Plugin exports symbols as interfaces. Mark their types as used in
interfaces, so their methods will be kept alive by the linker.
Fixes#42579.
Change-Id: If1b5aacc21510c20c25f88bb131bca61db6f1d56
Reviewed-on: https://go-review.googlesource.com/c/go/+/269819
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
It turns out that the relative-path support never worked in the first
place.
It had been masked by the fact that we ~never invoke overlayDir with
an absolute path, which caused filepath.Rel to always return an error,
and overlayDir to always fall back to absolute paths.
Since the absolute paths seem to be working fine (and are simpler),
let's stick with those. As far as I can recall, the relative paths
were only a space optimization anyway.
Updates #28387
Updates #30316
Change-Id: Ie8cd28f3c41ca6497ace2799f4193d7f5dde7a37
Reviewed-on: https://go-review.googlesource.com/c/go/+/208481
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
One of the 'go build' commands executed by this test passed the '-i'
flag, which caused the 'go' command to attempt to install transitive
standard-library dependencies to GOROOT/pkg/$GOOS_$GOARCH_dynlink.
That failed if GOROOT/pkg was not writable (for example, if GOROOT was
owned by the root user, but the user running the test was not root).
As far as I can tell the '-i' flag is not necessary in this test.
Prior to the introduction of the build cache it may have been an
optimization, but now that the build cache is required the '-i' flag
only adds extra work.
Updates #30316
Change-Id: Ib60080a008c1941aa92b5bdd5a194d89fd6202aa
Reviewed-on: https://go-review.googlesource.com/c/go/+/208120
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The problem causing the assert in #21647 are fixed at this point,
along with various other linker issues with plugin + Darwin. With
this in mind, remove the "-ldflags=-w" workaround for plugin mode on
Darwin and re-enable the appropriate tests misc/cgo/testplugin
Fixes#21647.
Fixes#27502.
Change-Id: I5b662987b138b06cfc9e1f9f6d804cf682bd501a
Reviewed-on: https://go-review.googlesource.com/c/go/+/206198
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
These tests take 20 seconds each to rebuild the entire world
in their respective modes. That's too much for short mode,
including all.bash on developer machines.
Keep doing it on builders and if someone runs 'go test' by hand
in that directory.
For #26473.
Change-Id: I3dc6955bc3aa7a20fd170efcde72a7d19b37bdbf
Reviewed-on: https://go-review.googlesource.com/c/go/+/177417
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Split TestMain into two functions so that we can defer cleanups.
Updates #30500
Change-Id: I4a5c7ddb8218a8bd056c8733c3cb9feb895e77a0
Reviewed-on: https://go-review.googlesource.com/c/164859
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
I hope that this will fix the tests on iOS, but 'gomote create' isn't
giving me an instance I can test with. (Please patch and test before
approving.)
Updates #15919
Updates #30228
Change-Id: I1b7cd30d5b127a1ad3243b329fa005d229f69a24
Reviewed-on: https://go-review.googlesource.com/c/163726
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Elias Naur <mail@eliasnaur.com>
For some reason on darwin the linker still can't add debug sections to
plugins. Executables importing "plugin" do have them, however.
Because of issue 25841, plugins on darwin would likely have bad debug
info anyway so, for now, this isn't a great loss.
This disables the check for debug sections in plugins for darwin only.
Updates #27502
Change-Id: Ib8f62dac1e485006b0c2b3ba04f86d733db5ee9a
Reviewed-on: https://go-review.googlesource.com/133435
Reviewed-by: Brad Fitzpatrick <bradfitz@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>
When using plugins with goroutines calling cgo, we hit a case where
an intermittent SIGSEGV occurs when referencing an address that is based
on r2 (TOC address). When the failure can be generated in gdb, the
contents of r2 is wrong even though the value in the current stack's
slot for r2 is correct. So that means it somehow switched to start
running the code in this function without passing through the beginning
of the function which had the correct value of r2 and stored it there.
It was noted that in runtime.gogo when the state is restored from
gobuf, r2 is not restored from its slot on the stack. Adding the
instruction to restore r2 prevents the SIGSEGV.
This adds a testcase under testplugin which reproduces the problem if
the program is run multiple times. The team who reported this problem
has verified it fixes the issue on their larger, more complex
application.
Fixes#25756
Change-Id: I6028b6f1f8775d5c23f4ebb57ae273330a28eb8f
Reviewed-on: https://go-review.googlesource.com/117515
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When there are plugins, there may not be a unique copy of runtime
functions like goexit, mcall, etc. So identifying them by entry
address is problematic. Instead, keep track of each special function
using a field in the symbol table. That way, multiple copies of
the same runtime function will be treated identically.
Fixes#24351Fixes#23133
Change-Id: Iea3232df8a6af68509769d9ca618f530cc0f84fd
Reviewed-on: https://go-review.googlesource.com/100739
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixed by CL 76025 yesterday, without realizing it:
the testshared and testplugin builds of separate iface_i
packages were colliding incorrectly in the cache.
Including the build directory fixes that.
Fixes#22571.
Change-Id: Id8193781c67c3150823dc1f48eae781dfe3702fb
Reviewed-on: https://go-review.googlesource.com/76371
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This CL adds caching of successful test results, keyed by the
action ID of the test binary and its command line arguments.
Suppose you run:
go test -short std
<edit a typo in a comment in math/big/float.go>
go test -short std
Before this CL, the second go test would re-run all the tests
for the std packages. Now, the second go test will use the cached
result immediately (without any compile or link steps) for any
packages that do not transitively import math/big, and then
it will, after compiling math/big and seeing that the .a file didn't
change, reuse the cached test results for the remaining packages
without any additional compile or link steps.
Suppose that instead of editing a typo you made a substantive
change to one function, but you left the others (including their
line numbers) unchanged. Then the second go test will re-link
any of the tests that transitively depend on math/big, but it still
will not re-run the tests, because the link will result in the same
test binary as the first run.
The only cacheable test arguments are:
-cpu
-list
-parallel
-run
-short
-v
Using any other test flag disables the cache for that run.
The suggested argument to mean "turn off the cache" is -count=1
(asking "please run this 1 time, not 0").
There's an open question about re-running tests when inputs
like environment variables and input files change. For now we
will assume that users will bypass the test cache when they
need to do so, using -count=1 or "go test" with no arguments.
This CL documents the new cache but also documents the
previously-undocumented distinction between "go test" with
no arguments (now called "local directory mode") and with
arguments (now called "package list mode"). It also cleans up
a minor detail of package list mode buffering that used to change
whether test binary stderr was sent to go command stderr based
on details like exactly how many packages were listed or
how many CPUs the host system had. Clearly the file descriptor
receiving output should not depend on those, so package list mode
now consistently merges all output to stdout, where before it
mostly did that but not always.
Fixes#11193.
Change-Id: I120edef347b9ddd5b10e247bfd5bd768db9c2182
Reviewed-on: https://go-review.googlesource.com/75631
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Both the linker and the plugin package were inconsistent
about when they applied the path encoding defined in
objabi.PathToPrefix. As a result, only some symbols from
a package path that required encoding were being found.
So always encoding the path.
Fixes#22295
Change-Id: Ife86c79ca20b2e9307008ed83885e193d32b7dc4
Reviewed-on: https://go-review.googlesource.com/72390
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Running test.bash goes from 30s to 10s on a linux workstation.
(The coming pkg cache work in cmd/go would presumably do the same thing,
but this makes all.bash faster today.)
Change-Id: I8c9b0400071a412fce55b386e939906bb1c1d84d
Reviewed-on: https://go-review.googlesource.com/72330
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently we look to see if the main.main symbol address is in the
module data text range. This requires access to the main.main
symbol, which usually the runtime has, but does not when building
a plugin.
To avoid a dynamic relocation to main.main (which I haven't worked
out how to have the linker generate on darwin), stop using the
symbol. Instead record a boolean in the moduledata if the module
has the main function.
Fixes#22175
Change-Id: If313a118f17ab499d0a760bbc2519771ed654530
Reviewed-on: https://go-review.googlesource.com/69370
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Moves type symbol name mangling out of the object reader
and into a separate pass. Requires some care, as changing
the name of a type may require dealing with duplicate
symbols for the first time.
Disables DWARF for both plugins and programs that use plugin.Open,
because type manging is currently incompatible with the go.info.*
symbol generator in cmd/link. (It relies on the symbol names to
find type information.) A future fix for this would be moving the
go.info.* generation into the compiler, with the logic we use
for generating the type.* symbols.
Fixes#19529
Change-Id: I75615f8bdda86ff9e767e536d9aa36e15c194098
Reviewed-on: https://go-review.googlesource.com/67312
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The noopt builder sets GO_GCFLAGS when building the standard library.
Set it when building plugins to ensure the -shared packages built for it
have the same inlining in the export data (and thus the same package
version).
Tested locally with GO_GCFLAGS="-N -l" ./all.bash
Fixes#17937
Change-Id: Id037cfbf4af744c05c47bdc58eea60a5dba69533
Reviewed-on: https://go-review.googlesource.com/62511
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
1. remove broken verification
The runtime check assumes that no-pcln symbol entry have zero value,
but the linker emit no entries if the symbol is no-pcln.
As a result, if there are no-pcln symbols at the very end of pcln
table, it will panic.
2. correct condition of export
Handle special chracters in pluginpath correcty.
Export "go.itab.*", so different plugins can share the same itab.
Fixes#18190
Change-Id: Ia4f9c51d83ce8488a9470520f1ee9432802cfc1d
Reviewed-on: https://go-review.googlesource.com/61091
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Along the way, track bad modules. Make sure they don't end up on
the active modules list, and aren't accidentally reprocessed as
new plugins.
Fixes#19004
Change-Id: I8a5e7bb11f572f7b657a97d521a7f84822a35c07
Reviewed-on: https://go-review.googlesource.com/61171
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It is common to have multiple plugins built from ephemeral
source files all with the same name:
# generate main.go
go build -buildmode=plugin -o=p1.so main.go
# rm main.go, generate new main.go
go build -buildmode=plugin -o=p2.so main.go
...
These different plugins currently have the same build ID,
and hence the same package path. This means only one can be
loaded.
To remove this restriction, this commit adds the contents of the
main package source files to the plugin hash.
Fixes#19358
Change-Id: Icd42024b085feb29c09c2771aaecb85f8b528dd3
Reviewed-on: https://go-review.googlesource.com/61170
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When compiling a plugin, package main gets a new name so as not to
conflict with the main package in the host binary, or any other
plugins. It is already defined by cmd/go, and used by cmd/link when
filling out the "" package placeholder in symbols.
With this CL, the plugin-specific name for main is also passed to
cmd/compile's -p flag. This is used to fill out the pkgpath field
of types, and ensures that two types defined in two different plugin
mains with the same name will not be mistaken for one another at
runtime.
Fixes#21386
Change-Id: I8a646d8d7451caff533fe0007343ea8b8e1704ed
Reviewed-on: https://go-review.googlesource.com/60910
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Prevent a crash if the same type in two plugins had a recursive
definition, either by referring to a pointer to itself or a map existing
with the type as a value type (which creates a recursive definition
through the overflow bucket type).
Fixes#19258
Change-Id: Iac1cbda4c5b6e8edd5e6859a4d5da3bad539a9c6
Reviewed-on: https://go-review.googlesource.com/40292
Run-TryBot: Todd Neal <todd@tneal.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
We already do this for shared libraries. Do it for plugins also.
Suggestions on how to test this would be welcome.
I'd like to get this in for 1.8. It could lead to mysterious
hangs when using plugins.
Fixes#18676
Change-Id: I03209b096149090b9ba171c834c5e59087ed0f92
Reviewed-on: https://go-review.googlesource.com/35117
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Make sure that the same type and itab generated in two
different plugins are actually the same thing.
See also CL 35115
Change-Id: I0c1ecb039d7e2bf5a601d58dfa162a435ae4ef76
Reviewed-on: https://go-review.googlesource.com/35116
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Explicitly filter any C-only cgo functions out of pclntable,
which allows them to be duplicated with the host binary.
Updates #18190.
Change-Id: I50d8706777a6133b3e95f696bc0bc586b84faa9e
Reviewed-on: https://go-review.googlesource.com/34199
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The pclntable contains pointers to functions. If the function symbol
is exported in a plugin, and there is a matching symbol in the host
binary, then the pclntable of a plugin ends up pointing at the
function in the host module.
This doesn't work because the traceback code expects the pointer to
be in the same module space as the PC value.
So don't export functions that might overlap with the host binary.
This way the pointer stays in its module.
Updates #18190
Change-Id: Ifb77605b35fb0a1e7edeecfd22b1e335ed4bb392
Reviewed-on: https://go-review.googlesource.com/34196
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
To generate the correct section offset the shared code path for
R_CALL, R_PCREL, and R_GOTPCREL on darwin when externally linking
walks up the symbol heirarchy adding the differences. This is fine,
except in the case where we are generating a GOT lookup, because
the topmost symbol is left in r.Xsym instead of the symbol we are
looking up. So all funcsym GOT lookups were looking up the outer
"go.func.*" symbol.
Fix this by separating out the R_GOTPCREL code path.
For #17828 (and may fix it).
Change-Id: I2c9f4d135e77c17270aa064d8c876dc6d485d659
Reviewed-on: https://go-review.googlesource.com/33211
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In plugins and every program that opens a plugin, include a hash of
every imported package.
There are two versions of each hash: one local and one exported.
As the program starts and plugins are loaded, the first exported
symbol for each package becomes the canonical version.
Any subsequent plugin's local package hash symbol has to match the
canonical version.
Fixes#17832
Change-Id: I4e62c8e1729d322e14b1673bada40fa7a74ea8bc
Reviewed-on: https://go-review.googlesource.com/33161
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The exported symbol for a plugin can be the only reference to a
type in a program. In particular, "var F func()" will have
the type *func(), which is uncommon.
Fixes#17140
Change-Id: Ide2104edbf087565f5377374057ae54e0c00c57e
Reviewed-on: https://go-review.googlesource.com/29692
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
A plugin with no exported symbols is still potentially very useful.
Its init functions are called on load, and it so it can have visible
side effects.
Fixes#17681
Change-Id: Icdca31f48e5ab13c99020a2ef724f3de47dcd74b
Reviewed-on: https://go-review.googlesource.com/32437
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
