The //go:linkname directive can be used to make a symbol accessible to
another package (when it wouldn't normally be). Sometimes you want to
do this without actually changing the symbol's object file symbol
name; for example, in gccgo this makes unexported symbols non-static,
and in gc this provides ABI0 wrappers for Go symbols so they can be
called from assembly in other packages. Currently, this results in
stutter like
//go:linkname entersyscall runtime.entersyscall
This CL makes the second argument to go:linkname optional for the case
where the intent is simply to expose the symbol rather than to rename
it in the object file.
Updates #31230.
Change-Id: Id06d9c4b2ec3d8e27f9b8a0d65212ab8048d734f
Reviewed-on: https://go-review.googlesource.com/c/go/+/179861
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Fixes#26533
Change-Id: I5a48d667d474f3f222f9055e51131561a0cf45b6
Reviewed-on: https://go-review.googlesource.com/c/138757
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The default language version is the current one.
For testing purposes, added a check that type aliases require version
go1.9. There is no consistent support for changes made before 1.12.
Updates #28221
Change-Id: Ia1ef63fff911d5fd29ef79d5fa4e20cfd945feb7
Reviewed-on: https://go-review.googlesource.com/c/144340
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Nowadays there are better ways to safely run untrusted Go programs, like
NaCl and gVisor.
Change-Id: I20c45f13a50dbcf35c343438b720eb93e7b4e13a
Reviewed-on: https://go-review.googlesource.com/c/142717
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This flag is experimental and the semantics may change
even after Go 1.7 is released. There are no changes to code
not using the flag.
The first part is for reading by future compiles.
The second part is for reading by the final link step.
Splitting the file this way allows distributed build systems
to ship the compile-input part only to compile steps and
the linker-input part only to linker steps.
The first part is basically just the export data,
and the second part is basically everything else.
The overall files still have the same broad structure,
so that existing tools will work with both halves.
It's just that various pieces are empty in the two halves.
This also copies the two bits of data the linker needed from
export data into the object header proper, so that the linker
doesn't need any export data at all. That eliminates a TODO
that was left for switching to the binary export data.
(Now the linker doesn't need to know about the switch.)
The default is still to write out a combined output file.
Nothing changes unless you pass -linkobj to the compiler.
There is no support in the go command for -linkobj,
since the go command doesn't copy objects around.
The expectation is that other build systems (like bazel, say)
might take advantage of this.
The header adjustment and the option for the split output
was intended as part of the zip archives, but the zip archives
have been cut from Go 1.7. Doing this to the current archives
both unblocks one step in the switch to binary export data
and enables alternate build systems to experiment with the
new flag using the Go 1.7 release.
Change-Id: I8b6eab25b8a22b0a266ba0ac6d31e594f3d117f3
Reviewed-on: https://go-review.googlesource.com/22500
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The -msan option causes the compiler to add instrumentation for the
C/C++ memory sanitizer. Every memory read/write will be preceded by
a call to msanread/msanwrite.
This CL passes tests but is not usable by itself. The actual
implementation of msanread/msanwrite in the runtime package, and support
for -msan in the go tool and the linker, and tests, will follow in
subsequent CLs.
Change-Id: I3d517fb3e6e65d9bf9433db070a420fd11f57816
Reviewed-on: https://go-review.googlesource.com/16160
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The -importmap option takes an argument of the form old=new
and specifies that import "old" should be interpreted as if it said
import "new". The option may be repeated to specify multiple mappings.
This option is here to support the go command's new -vendor flag.
Change-Id: I31b4ed4249b549982a720bf61bb230462b33c59b
Reviewed-on: https://go-review.googlesource.com/10922
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These are the Go 1.4 docs but refreshed for Go 1.5.
The most sigificant change is that all references to the Plan 9 toolchain are gone.
The tools no longer bear any meaningful resemblance.
Change-Id: I44f5cadb832a982323d7fee0b77673e55d761b35
Reviewed-on: https://go-review.googlesource.com/10298
Reviewed-by: Rob Pike <r@golang.org>
