The Go 1.6 release notes say we'll remove the “-X name value” form
(in favor of the “-X name=value” form) in Go 1.7.
Do that.
Also establish the doc/go1.7.txt file.
Change-Id: Ie4565a6bc5dbcf155181754d8d92bfbb23c75338
Reviewed-on: https://go-review.googlesource.com/19614
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This call to os.Getwd (or getwd) has been part of the linker since the C
implementation in 7d507dc6e6. It stopped being used in 26438d4d80, and
survived the conversion to Go in 1f9dbb60ef.
Its return value goes unused (the linker gets the value for AT_comp_dir in
dwarf.go), remove it.
Change-Id: I3d4594813bb4ee0a6af31a36e19d99ec4b863677
Reviewed-on: https://go-review.googlesource.com/19655
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add the following flags when supported by the compiler:
-gno-record-gcc-switches
-fdebug-prefix-map=$WORK=/tmp/go-build
Add an empty NAME symbol to the ELF .symtab. GNU ld will add a NAME
symbol when one is not present; including one of our own prevents it
from adding a reference to the link tempdir.
Fixes#13247 for compilers that support -fdebug-prefix-map. (gcc, clang
in the near future.)
Change-Id: I221c71fc59cd23ee8c99bcc038793ff4623c9ffc
Reviewed-on: https://go-review.googlesource.com/19363
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>
Fields in Plan 9 object headers are big-endian, on all architectures.
Change-Id: If95ad29750b776338178d660646568bf26a4abda
Reviewed-on: https://go-review.googlesource.com/18964
Reviewed-by: Russ Cox <rsc@golang.org>
People who want to use -buildmode=c-archive in unusual cross-compilation
setups will need something like this. It could also be done via (yet
another) environment variable but I use -extar by analogy with the
existing -extld.
Change-Id: I354cfabc4c470603affd13cd946997b3a24c0e6c
Reviewed-on: https://go-review.googlesource.com/18913
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
https://golang.org/s/execmodes defines rules for how multiple codes of a go
package work when they end up in the address space of a single process, but
currently the linker blows up in this situation. Fix that by loading all .a
files before any .so files and ignoring duplicate symbols found when loading
shared libraries.
I know this is very very late for 1.6 but at least it should clearly not have
any effect when shared libraries are not in use.
Change-Id: I512ac912937e7502ff58eb5628b658ecce3c38e5
Reviewed-on: https://go-review.googlesource.com/18714
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
The linker already applies the fix for elf32, so this just extends it to elf64.
Inspired by https://github.com/pwaller/goupxFixes#13974
Change-Id: I65d92b5be9590657060a0e8e80ff5b86ba40017f
Reviewed-on: https://go-review.googlesource.com/18690
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This makes lldb willing to debug them.
The minimum version is hard-coded at OS X 10.7,
because that is the minimum that Go requires.
For more control over the version, users can
use linkmode=external and pass the relevant flags to the host linker.
Fixes#12941.
Change-Id: I20027be8aa034d07dd2a3326828f75170afe905f
Reviewed-on: https://go-review.googlesource.com/18588
Reviewed-by: Ian Lance Taylor <iant@golang.org>
* Enable c-shared buildmode on darwin/386
* dyld does not support text relocation on i386. Add -read_only_relocs suppress flag to linker
Fixes#13904
Change-Id: I9adbd20d3f36ce9bbccf1bffb746b391780d088f
Reviewed-on: https://go-review.googlesource.com/18500
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
On Windows, externalthreadhandler currently sets the assumed stack
size for the profiler thread and the ctrlhandler threads to 8KB. The
actual stack size is determined by the SizeOfStackReserve field in the
binary set by the linker, which is currently at least 64KB (and
typically 128KB).
It turns out the profiler thread is running within a few words of the
8KB-(stack guard) bound set by externalthreadhandler. If it overflows
this bound, morestack crashes unceremoniously with an access
violation, which we then fail to handle, causing the whole process to
exit without explanation.
To avoid this problem and give us some breathing room, increase the
assumed stack size in externalthreadhandler to 32KB (there's some
unknown amount of stack already in use, so it's not safe to increase
this all the way to the reserve size).
We also document the relationships between externalthreadhandler and
SizeOfStackReserve to make this more obvious in the future.
Change-Id: I2f9f9c0892076d78e09827022ff0f2bedd9680a9
Reviewed-on: https://go-review.googlesource.com/18304
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Minux Ma <minux@golang.org>
This CL changes the source file information in the
standard library's .a files to say "$GOROOT/src/runtime/chan.go"
(with a literal "$GOROOT") instead of spelling out the actual directory.
The linker then substitutes the actual $GOROOT (or $GOROOT_FINAL)
as appropriate.
If people download a binary distribution to an alternate location,
following the instructions at https://golang.org/doc/install#install,
the code before this CL would end up with source paths pointing to
/usr/local/go no matter where the actual sources were.
Now the source paths for built binaries will point to the actual sources
(hopefully).
The source line information in distributed binaries is not affected:
those will still say /usr/local/go. But binaries people build themselves
(their own programs, not the go distribution programs) will be correct.
Fixing this path also fixes the lookup of the runtime-gdb.py file.
Fixes#5533.
Change-Id: I03729baae3fbd8cd636e016275ee5ad2606e4663
Reviewed-on: https://go-review.googlesource.com/18200
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The test for non-package main top-level inputs is done while parsing
the export data. Issue #13468 happened because we were not parsing
the export data when using compiler-generated archives
(that is, when using go tool compile -pack).
Fix this by parsing the export data even for archives.
However, that turns up a different problem: the export data check
reports (one assumes spurious) skew errors now, because it has
not been run since Go 1.2.
(Go 1.3 was the first release to use go tool compile -pack.)
Since the code hasn't run since Go 1.2, it can't be that important.
Since it doesn't work today, just delete it.
Figuring out how to make this code work with Robert's export
format was one of the largest remaining TODOs for that format.
Now we don't have to.
Fixes#13468 and makes the world a better place.
Change-Id: I40a4b284cf140d49d48b714bd80762d6889acdb9
Reviewed-on: https://go-review.googlesource.com/17976
Reviewed-by: Robert Griesemer <gri@golang.org>
Try to remove the most visible artefacts resulting from the
C to Go translation. It includes:
- refactoring the find function to eliminate goto and variable declarations
- removing useless variables still having a _ = xxx
- decreasing the number of upfront variable declarations
No semantic changes.
Change-Id: I84d981c48b2d9e22e6b9db5f2a703c80c60249ba
Reviewed-on: https://go-review.googlesource.com/15681
Reviewed-by: Russ Cox <rsc@golang.org>
This relocation is found in libgcc.a in the .eh_frame, and therefore
needs to be handled when doing an internal link.
Fixes#13375.
Change-Id: Idd9e8178e08851a101b43261a30939bcfaf394f9
Reviewed-on: https://go-review.googlesource.com/17173
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
All the heavy lifting was done by Michael Hudson-Doyle.
Change-Id: I176f15581055078854c2ad9a5807c4dcf0f8d8c5
Reviewed-on: https://go-review.googlesource.com/17074
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Does not fix#12327 but nicer anyway.
Change-Id: I4ad730a4ca833d76957b7571895b3a08a6a530d4
Reviewed-on: https://go-review.googlesource.com/16964
Reviewed-by: Ian Lance Taylor <iant@golang.org>
An internal link may need the C compiler support library, libgcc.a. Add
a -libgcc option to set the name of the compiler support library. If
-libgcc is not used, run the compiler to find it. Permit -libgcc=none
to skip using libgcc at all and hope for the best.
Change cmd/dist to not copy libgcc into the distribution. Add tests to
ensure that all the standard packages that use cgo can be linked in
internal mode without using libgcc. This ensures that somebody with a
Go installation without a C compiler can build programs.
Change-Id: I8ba35fb87ab0dd20e5cc0166b5f4145b04ce52a4
Reviewed-on: https://go-review.googlesource.com/16993
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
This includes the first parts of the general approach to PIC: load PC into CX
whenever it is needed. This is going to lead to large binaries and poor
performance but it's a start and easy to get right.
Change-Id: Ic8bf1d0a74284cca0d94a68cf75024e8ab063b4e
Reviewed-on: https://go-review.googlesource.com/16383
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change the linker to use a copy of the C compiler support library,
libgcc.a, when doing internal linking. This will be used to satisfy any
undefined symbols referenced by host objects.
Change the dist tool to copy the support library into a new directory
tree under GOROOT/pkg/libgcc. This ensures that libgcc is available
even when building Go programs on a system that has no C compiler. The
C compiler is required when building the Go installation in the first
place, but is not required thereafter.
Change the go tool to not link libgcc into cgo objects.
Correct the linker handling of a weak symbol in an ELF input object to
not always create a new symbol, but to use an existing symbol if there
is one; this is necessary on freebsd-amd64, where libgcc contains a weak
definition of compilerrt_abort_impl.
Fixes#9510.
Change-Id: I1ab28182263238d9bcaf6a42804e5da2a87d8778
Reviewed-on: https://go-review.googlesource.com/16741
Reviewed-by: Russ Cox <rsc@golang.org>
This requires changing the tls access code to match the patterns documented in
the ABI documentation or the system linker will "optimize" it into ridiculousness.
With this change, -buildmode=pie works, although as it is tested in testshared,
the tests are not run yet.
Change-Id: I1efa6687af0a5b8db3385b10f6542a49056b2eb3
Reviewed-on: https://go-review.googlesource.com/15971
Reviewed-by: Russ Cox <rsc@golang.org>
The PowerPC ISA does not have a PC-relative load instruction, which poses
obvious challenges when generating position-independent code. The way the ELFv2
ABI addresses this is to specify that r2 points to a per "module" (shared
library or executable) TOC pointer. Maintaining this pointer requires
cooperation between codegen and the system linker:
* Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer.
* A call to a function that *might* have to go via a PLT stub must be followed
by a nop instruction that the system linker can replace with "ld r1, 24(r1)"
to restore the TOC pointer (only when dynamically linking Go code).
* When calling a function via a function pointer, the address of the function
must be in r12, and the first couple of instructions (the "global entry
point") of the called function use this to derive the address of the TOC
for the module it is in.
* When calling a function that is implemented in the same module, the system
linker adjusts the call to skip over the instructions mentioned above (the
"local entry point"), assuming that r2 is already correctly set.
So this changeset adds the global entry point instructions, sets the metadata so
the system linker knows where the local entry point is, inserts code to save the
TOC pointer at 24(r1), adds a nop after any call not known to be local and copes
with the odd non-local code transfer in the runtime (e.g. the stuff around
jmpdefer). It does not actually compile PIC yet.
Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854
Reviewed-on: https://go-review.googlesource.com/15967
Reviewed-by: Russ Cox <rsc@golang.org>
The larger stack frames causes the nosplit stack to overflow so the next change
increases the stackguard.
Change-Id: Ib2b4f24f0649eb1d13e3a58d265f13d1b6cc9bf9
Reviewed-on: https://go-review.googlesource.com/15964
Reviewed-by: Russ Cox <rsc@golang.org>
Only internal linking without cgo is supported for now.
Change-Id: Ie6074a8ff3ec13605b72028f2d60758034f87185
Reviewed-on: https://go-review.googlesource.com/14444
Reviewed-by: Minux Ma <minux@golang.org>
The linker writes the number of file symbols (Nhistfile) to the filetab slice
and then Nhistfile offsets -- which means the slice contains Nhistfile+1
entries, not just Nhistfile.
I think this bug has been around since at least 1.4 but it's easier to trigger
with shared libraries and a tiny binary that only has a couple of functions in
it -- try go install -buildmode=shared std && go run -linkshared test/fixedbugs/issue4388.go.
Change-Id: I6c0f01f1e607b9b2b96872e37ffce81281911504
Reviewed-on: https://go-review.googlesource.com/16342
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
They reportedly occur with LLVM 3.7 on FreeBSD ARM.
Fixes#13139.
Change-Id: Ia7d053a8662696b1984e81fbd1d908c951c35a98
Reviewed-on: https://go-review.googlesource.com/16667
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
golang.org/cl/16436 added a local symbol for every global function, but also
added a duplicate entry for the global symbol. Surprisingly this hasn't caused
any noticeable problems, but it's still wrong.
Change-Id: Icd3906760f8aaf7bef31ffd4f2d866d73d36dc2c
Reviewed-on: https://go-review.googlesource.com/16581
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The GNU binutils recently picked up support for new 386/amd64
relocations. Add support for them in the Go linker when doing an
internal link.
The 386 relocation R_386_GOT32X was proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I . It can
be treated as identical to the R_386_GOT32 relocation.
The amd64 relocations R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were
proposed in
https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0 . They
can both be treated as identical to the R_X86_64_GOTPCREL relocation.
The purpose of the new relocations is to permit additional linker
relaxations in some cases. We do not attempt to support those cases.
While we're at it, remove the unused and in some cases out of date
_COUNT names from ld/elf.go.
Fixes#13114.
Change-Id: I34ef07f6fcd00cdd2996038ecf46bb77a49e968b
Reviewed-on: https://go-review.googlesource.com/16529
Reviewed-by: Minux Ma <minux@golang.org>
