This CL replays the following one CL from the rsc-go13nacl repo.
This is the last replay CL: after this CL the main repo will have
everything the rsc-go13nacl repo did. Changes made to the main
repo after the rsc-go13nacl repo branched off probably mean that
NaCl doesn't actually work after this CL, but all the code is now moved
over and just needs to be redebugged.
---
cmd/6l, cmd/8l, cmd/ld: support for Native Client
See golang.org/s/go13nacl for design overview.
This CL is publicly visible but not CC'ed to golang-dev,
to avoid distracting from the preparation of the Go 1.2
release.
This CL and the others will be checked into my rsc-go13nacl
clone repo for now, and I will send CLs against the main
repo early in the Go 1.3 development.
R≡khr
https://golang.org/cl/15750044
---
LGTM=bradfitz, dave, iant
R=dave, bradfitz, iant
CC=golang-codereviews
https://golang.org/cl/69040044
The "fat" referred to being used for multiword values only.
We're going to use it for non-fat values sometimes too.
No change other than the renaming.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63650043
We now use the %A, %D, %P, and %R routines from liblink
across the board.
Fixes#7178.
Fixes#7055.
LGTM=iant
R=golang-codereviews, gobot, rsc, dave, iant, remyoudompheng
CC=golang-codereviews
https://golang.org/cl/49170043
rsc suggested that we split the whole linker changes into three parts.
This is the first one, mostly dealing with adding Hsolaris.
LGTM=iant
R=golang-codereviews, iant, dave
CC=golang-codereviews
https://golang.org/cl/54210050
CL 56120043 fixed and cleaned up TLS on ARM after introducing liblink, but
left flag_shared broken. This CL restores the (unsupported) flag_shared
behaviour by simply rewriting access to $runtime.tlsgm(SB) with
runtime.tlsgm(SB), to compensate for the extra indirection when going from
the R_ARM_TLS_LE32 relocation to the R_ARM_TLS_IE32 relocation.
Also, remove unnecessary symbol lookup left after 56120043.
LGTM=iant
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/57000043
CL 56120043 fixed TLS handling on ARM after the introduction of
liblink but left older ARM processors broken.
Before liblink, the MRC instruction was replaced with a fallback
on older ARMs. CL 56120043 removed that, because the rewrite matched
bit patterns on the AWORD pseudo-instruction and could therefore change
unrelated AWORDs that happened to match.
This CL adds an AMRC instruction to encode both MRC and MCR previously
encoded as AWORDs. Then, in liblink, the AMRC instructions are either
rewritten to AWORD, or, on goarm < 7, replaced with a branch to the
fallback.
./all.bash completes successfully on an ARMv7 with either GOARM=7 or
GOARM=5. I have verified that the fallback is indeed present in both
runtime.save_gm and runtime.load_gm when GOARM=5 but not when GOARM=7.
If all goes well, this should fix the armv5 builders.
LGTM=iant
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/55540044
The addition of TLS to ARM rewrote the MRC instruction
differently depending on whether we were using internal
or external linking mode. That's clearly not okay, since we
don't know that during compilation, which is when we now
generate the code. Also, because the change did not introduce
a real MRC instruction but instead just macro-expanded it
in the assembler, liblink is rewriting a WORD instruction that
may actually be looking for that specific constant, which would
lead to very unexpected results. It was also using one value
that happened to be 8 where a different value that also
happened to be 8 belonged. So the code was correct for those
values but not correct in general, and very confusing.
Throw it all away.
Replace with the following. There is a linker-provided symbol
runtime.tlsgm with a value (address) set to the offset from the
hardware-provided TLS base register to the g and m storage.
Any reference to that name emits an appropriate TLS relocation
to be resolved by either the internal linker or the external linker,
depending on the link mode. The relocation has exactly the
semantics of the R_ARM_TLS_LE32 relocation, which is what
the external linker provides.
This symbol is only used in two routines, runtime.load_gm and
runtime.save_gm. In both cases it is now used like this:
MRC 15, 0, R0, C13, C0, 3 // fetch TLS base pointer
MOVW $runtime·tlsgm(SB), R2
ADD R2, R0 // now R0 points at thread-local g+m storage
It is likely that this change breaks the generation of shared libraries
on ARM, because the MOVW needs to be rewritten to use the global
offset table and a different relocation type. But let's get the supported
functionality working again before we worry about unsupported
functionality.
LGTM=dave, iant
R=iant, dave
CC=golang-codereviews
https://golang.org/cl/56120043
Now that liblink is compiled into the compilers and assemblers,
it must not refer to the "linkmode", since that is not known until
link time. This CL makes the ARM support no longer use linkmode,
which fixes a bug with cgo binaries that contain their own TLS
variables.
The x86 code must also remove linkmode; that is issue 7164.
Fixes#6992.
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/55160043
Many calls to symgrow pass a vlong value. Change the function
to not implicitly truncate, and to instead give an error if
the value is too large.
R=golang-codereviews, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/54010043
The %S and %N format verbs are used by cmd/gc to
represent Sym and Node structures, respectively.
In liblink, these two verbs are used only by the %D
format routine and never referenced externally.
This change will allow us to delete the duplicated
code for the %A, %D, %P, and %R format routines in
both the compiler and linker.
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/49720043
This restores the old behaviour, and makes it possible to
continue to use 6g and 6l directly, rather than the go tool,
with dot imports.
R=rsc
CC=golang-dev
https://golang.org/cl/43710043
- new object file reader/writer (liblink/objfile.c)
- remove old object file writing routines
- add pcdata iterator
- remove all trace of "line number stack" and "path fragments" from
object files, linker (!!!)
- dwarf now writes a single "compilation unit" instead of one per package
This CL disables the check for chains of no-split functions that
could overflow the stack red zone. A future CL will attack the problem
of reenabling that check (issue 6931).
This CL is just the liblink and cmd/ld changes.
There are minor associated adjustments in CL 37030045.
Each depends on the other.
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/39680043
- add buffered stdout to all tools and provide to link ctxt.
- avoid extra \n before ! in .6 files written by assemblers
(makes them match the C compilers).
- use linkwriteobj instead of linkouthist+linkwritefuncs.
- in assemblers and C compilers, record pc explicitly in Prog,
for use by liblink.
- in C compilers, preserve jump target links.
- in Go compilers (gsubr.c) attach gotype directly to
corresponding LSym* instead of rederiving from instruction stream.
- in Go compilers, emit just one definition for runtime.zerovalue
from each compilation.
This CL consists entirely of small adjustments.
The heavy lifting is in CL 39680043.
Each depends on the other.
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/37030045
There is an enormous amount of code moving around in this CL,
but the code is the same, and it is invoked in the same ways.
This CL is preparation for the new linker structure, not the new
structure itself.
The new library's definition is in include/link.h.
The main change is the use of a Link structure to hold all the
linker-relevant state, replacing the smattering of global variables.
The Link structure should both make it clearer which state must
be carried around and make it possible to parallelize more easily
later.
The main body of the linker has moved into the architecture-independent
cmd/ld directory. That includes the list of known header types, so the
distinction between Hplan9x32 and Hplan9x64 is removed (no other
header type distinguished 32- and 64-bit formats), and code for unused
formats such as ipaq kernels has been deleted.
The code being deleted from 5l, 6l, and 8l reappears in liblink or in ld.
Because multiple files are being merged in the liblink directory,
it is not possible to show the diffs nicely in hg.
The Prog and Addr structures have been unified into an
architecture-independent form and moved to link.h, where they will
be shared by all tools: the assemblers, the compilers, and the linkers.
The unification makes it possible to write architecture-independent
traversal of Prog lists, among other benefits.
The Sym structures cannot be unified: they are too fundamentally
different between the linker and the compilers. Instead, liblink defines
an LSym - a linker Sym - to be used in the Prog and Addr structures,
and the linker now refers exclusively to LSyms. The compilers will
keep using their own syms but will fill out the corresponding LSyms in
the Prog and Addr structures.
Although code from 5l, 6l, and 8l is now in a single library, the
code has been arranged so that only one architecture needs to
be linked into a particular program: 5l will not contain the code
needed for x86 instruction layout, for example.
The object file writing code in liblink/obj.c is from cmd/gc/obj.c.
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/35790044
