Commit graph

236 commits

Author SHA1 Message Date
Cherry Mui
e3f7816f0e cmd/link: remove name expansion logic
Now both the compiler and the assembler require the -p flag and
emit full package path in symbol names, we no longer need to do
the name expansion in the linker. Delete it.

Change-Id: I771d4d97987a0a17414881b52806d600ef4cc351
Reviewed-on: https://go-review.googlesource.com/c/go/+/404300
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>
2022-05-12 18:45:57 +00:00
Cherry Mui
df08c9a821 cmd/link: preserve symbol attributes when cloning to external
There are some symbol attributes that are encoded in the object
file. Currently, they are lost when cloning a symbol to external.
Copy them over.

Also delete CopyAttributes as it is no longer called anywhere.

Change-Id: I1497e3223a641704bf35aa3e904dd0eda2f8ec3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/400574
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2022-04-15 19:02:54 +00:00
Russ Cox
19309779ac all: gofmt main repo
[This CL is part of a sequence implementing the proposal #51082.
The design doc is at https://go.dev/s/godocfmt-design.]

Run the updated gofmt, which reformats doc comments,
on the main repository. Vendored files are excluded.

For #51082.

Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407
Reviewed-on: https://go-review.googlesource.com/c/go/+/384268
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-11 16:34:30 +00:00
Russ Cox
690ac4071f all: remove trailing blank doc comment lines
A future change to gofmt will rewrite

	// Doc comment.
	//
	func f()

to

	// Doc comment.
	func f()

Apply that change preemptively to all doc comments.

For #51082.

Change-Id: I4023e16cfb0729b64a8590f071cd92f17343081d
Reviewed-on: https://go-review.googlesource.com/c/go/+/384259
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-01 18:18:07 +00:00
Russ Cox
7d87ccc860 all: fix various doc comment formatting nits
A run of lines that are indented with any number of spaces or tabs
format as a <pre> block. This commit fixes various doc comments
that format badly according to that (standard) rule.

For example, consider:

	// - List item.
	//   Second line.
	// - Another item.

Because the - lines are unindented, this is actually two paragraphs
separated by a one-line <pre> block. This CL rewrites it to:

	//  - List item.
	//    Second line.
	//  - Another item.

Today, that will format as a single <pre> block.
In a future release, we hope to format it as a bulleted list.

Various other minor fixes as well, all in preparation for reformatting.

For #51082.

Change-Id: I95cf06040d4186830e571cd50148be3bf8daf189
Reviewed-on: https://go-review.googlesource.com/c/go/+/384257
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-01 18:18:01 +00:00
Cherry Mui
77680a0644 cmd/link: simplify content hashed symbol handling
Symbol's content hash used to depend on package path expansion in
symbol names, so we have special logic handling hashed symbols
when path expansion is needed. As we required -p in the compiler
the symbol names are now fully expanded. Remove that logic.

Change-Id: I888574f63ea3789455d96468a6abd500e0958230
Reviewed-on: https://go-review.googlesource.com/c/go/+/394218
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-22 19:39:12 +00:00
Cherry Mui
e853464055 cmd/compile, cmd/link: produce unlinkable object when compile without -p
CL 391014 requires the compiler to be invoked with the -p flag, to
specify the package path. People are used to run "go tool compile"
from the command line with the -p flag. This is mostly for simple
testing, or debugging the compiler. The produced object file is
almost never intended to be linked.

This CL makes the compiler allow "go tool compile" without the -p
flag again. It will produce an unlinkable object. If the linker
sees such an object it will error out.

Change-Id: I7bdb162c3cad61dadd5c456d903b92493a3df20f
Reviewed-on: https://go-review.googlesource.com/c/go/+/394217
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-22 19:38:35 +00:00
Cherry Mui
42d2d5e2b5 cmd/link: delete oReader.flags
Same information is provided from the fields of the embedded
goobj.Reader, and are accessed through it. Delete the flags field.

Change-Id: I7a4f5dca054e567443d719b2931fceff231d6efc
Reviewed-on: https://go-review.googlesource.com/c/go/+/394216
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>
2022-03-22 14:16:25 +00:00
Keith Randall
f92c8f07ac cmd/link: escape % characters in symbols when reporting errors
Generic function symbols sometimes have % in them, like:

    main.B2[%2eshape.string_0].m2·f

Which confuses this code because it doesn't esacpe % when
using this string as a format string, instead of a format argument.

Or could we get rid of the . -> %2e rewrite somehow?
I think it comes from LinkString.

Change-Id: I3275501f44cf30485e9d4577e0dfa77996d4939e
Reviewed-on: https://go-review.googlesource.com/c/go/+/357837
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
2021-10-25 20:41:00 +00:00
Cherry Mui
e180e2c27c cmd/internal/goobj, cmd/link: remove funcdataoff
FUNCDATA is always a symbol reference with 0 offset. Assert the
offset is 0 and remove funcdataoff.

Change-Id: I326815365c9db5aeef6b869df5d78a9957bc16a6
Reviewed-on: https://go-review.googlesource.com/c/go/+/352894
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-09-29 13:53:55 +00:00
Cherry Mui
587b3c1192 cmd/link: access pcdata via aux symbols
Pcdata are now separate aux symbols. Read them from aux, instead
of using funcinfo.

Now we can remove pcdata fields from funcinfo.

Change-Id: Ie65e3962edecc0f39127a5f6963dc59d1f141e67
Reviewed-on: https://go-review.googlesource.com/c/go/+/352893
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-09-29 13:53:07 +00:00
Keith Randall
a80cbc25bd runtime: elide instantiated types in tracebacks
They tend to be things like ".shape.int" which are noisy, if not
otherwise confusing.

It would be nice to somehow print the real instantiations here, but that
requires keeping track of the dictionary argument so the instantiating
types could be found. One day, maybe, but not today.

Fixes #48578

Change-Id: I0968d24e110b6d47c9468c45372a6979575a8d29
Reviewed-on: https://go-review.googlesource.com/c/go/+/352118
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
2021-09-27 19:29:58 +00:00
Cherry Mui
55d22f7490 cmd/link: remove ABI aliases
It is now gone.

Change-Id: I59f68b324af706476695de2f291dd3aa5734e192
Reviewed-on: https://go-review.googlesource.com/c/go/+/351332
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-09-22 15:49:52 +00:00
Cherry Mui
98989f2a74 cmd/compile, cmd/link: avoid ABI aliases
In the past we introduced ABI aliases, in preparation for ABI
wrappers. Now that we have ABI wrappers implemented, we don't
need ABI aliases. If ABI wrappers are not enabled, ABI0 and
ABIInternal are actually identical, so we can resolve symbol
references without distinguish them. This CL does so by
normalizing ABIInternal to ABI0 at link time. This way, we no
longer need to generate ABI aliases.

This CL doesn't clean up everything related to ABI aliases, which
will be done in followup CLs.

Change-Id: I5b5db43370d29b8ad153078c70a853e3263ae6f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/351271
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-09-22 13:50:24 +00:00
Alessandro Arzilli
6268468e02 cmd/link: generate DIE for types referenced only through dictionaries
Generate debug_info entries for types that are only referenced through
dictionaries.

Change-Id: Ic36c2e6d9588ec6746793bb213c2dc0e17a8a850
Reviewed-on: https://go-review.googlesource.com/c/go/+/350532
Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Trust: Dan Scales <danscales@google.com>
Trust: David Chase <drchase@google.com>
2021-09-20 18:31:54 +00:00
Tao Qingyun
4957976b1a cmd/link: make npkgsyms meaningful
npkgsyms always equals 1 currently.

Change-Id: Ie88bc273beaace12ec7432054ca7c151396e8e35
GitHub-Last-Rev: c5d3b12b88
GitHub-Pull-Request: golang/go#46988
Reviewed-on: https://go-review.googlesource.com/c/go/+/331929
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
2021-09-03 22:56:58 +00:00
Than McIntosh
49402bee36 cmd/{compile,link}: fix bug in map.zero handling
In CL 326211 a change was made to switch "go.map.zero" symbols from
non-pkg DUPOK symbols to hashed symbols. The intent of this change was
ensure that in cases where there are multiple competing go.map.zero
symbols feeding into a link, the largest map.zero symbol is selected.
The change was buggy, however, and resulted in duplicate symbols in
the final binary (see bug cited below for details). This duplication
was relatively benign for linux/ELF, but causes duplicate definition
errors on Windows.

This patch switches "go.map.zero" symbols back from hashed symbols to
non-pkg DUPOK symbols, and updates the relevant code in the loader to
ensure that we do the right thing when there are multiple competing
DUPOK symbols with different sizes.

Fixes #47185.

Change-Id: I8aeb910c65827f5380144d07646006ba553c9251
Reviewed-on: https://go-review.googlesource.com/c/go/+/334930
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-07-19 13:27:46 +00:00
Than McIntosh
07ca28d529 cmd/link: fix bug in -strictdups checking of BSS symbols
The linker's -strictdups debugging option was not properly checking
for cases where you have two dupok BSS symbols with different length
(the check examined data length and content, but not symbol size).

Updates #46653.

Change-Id: I3844f25ef76dd6e4a84ffd5caed5d19a1b1a57c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/326210
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-06-09 02:18:24 +00:00
Cherry Zhang
053fe2f485 cmd/link: emit better error for duplicated definition
Print the packages where the duplicates come from.

Change-Id: Ib3dc9aa0a3f5ddd97b03744be6d01d4bfcb33996
Reviewed-on: https://go-review.googlesource.com/c/go/+/315949
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>
2021-05-01 19:17:47 +00:00
Cherry Zhang
d80da19fc9 cmd/link: update comment for PLT/GOT helper functions
PLT and GOT are used more than on PE. Update the comment.

Change-Id: Iaddb326680a7709a1442675a38c021331be32472
Reviewed-on: https://go-review.googlesource.com/c/go/+/314929
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-04-29 14:06:55 +00:00
Russ Cox
59ceb985c7 cmd/link: make Loader.SymName not crash
Even if not presented with a valid symbol, recover gracefully,
so that debug prints do not crash.

Change-Id: I06bbe4bec5f90b79b4830e772a7fc3d7c919df1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/312036
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-04-23 21:43:02 +00:00
Austin Clements
69262d4871 cmd/compile,cmd/link: resolve cgo symbols to the correct Go ABI
Currently, Go functions exported to cgo have some confusion around
ABIs that leads to crashes. The cmd/cgo-generated C code references an
exported Go wrapper function (which calls the underlying exported user
function). The linker resolves this reference to the ABI0 entry-point
to that Go wrapper function because all host object references are
currently assumed to be to version 0 of a symbol. This gets passed via
crosscall2 and winds its way to cgocallbackg1, which puts this ABI0
entry-point into a function value and calls it. Unfortunately,
function values always use the ABIInternal calling convention, so
calling this ABI0 entry-point goes poorly.

Fix this by threading definition ABIs through the cgo export mechanism
so the linker can resolve host object references (which have no
concept of multiple ABIs) to the correct Go symbol. This involves a
few pieces:

- The compiler extends the cgo_export_{static,dynamic} directives that
  get passed on to the linker with symbol definition ABIs.

- The linker parses the ABIs in the cgo_export_{static,dynamic}
  directives to look up the right symbol to apply export attributes to
  and put in the dynexp list.

- For internal linking, the linker's Loader structure tracks the right
  symbol (in particular the right ABI) to resolve host object
  references to, and we use this in all of the host object loaders.

- For external linking, we mangle only the non-ABIInternal symbols
  now, so the external linker is able to resolve the correct reference
  from host objects to Go symbols.

Updates #40724.

Change-Id: I70a0b1610596768c3f473745fa1a3e630afbf1a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/309341
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-04-13 20:07:47 +00:00
Tao Qingyun
a78b12aea7 cmd/link: remove unnecessary attrReachable test
Change-Id: I5a6fde3ce57be1760cc8c92910fe77beb8b9c655
GitHub-Last-Rev: 0b2f3cb3a8
GitHub-Pull-Request: golang/go#45259
Reviewed-on: https://go-review.googlesource.com/c/go/+/305169
Reviewed-by: Than McIntosh <thanm@google.com>
Trust: David Chase <drchase@google.com>
2021-04-02 12:44:37 +00:00
Ian Lance Taylor
f82ce7fb23 cmd/link: improve nonexistent package error message
Change-Id: I207541efa6a34bc21e7a00584376622b59e2bf6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/302749
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2021-03-17 21:48:40 +00:00
Cherry Zhang
414fa8c35e cmd/internal/objabi: use a separate bit to mark weak relocation
Instead of using two relocation types R_XXX and R_WEAKXXX, use a
separate bit, R_WEAK, to mark weak relocations. This makes it
easier to add more weak relocation types.

Change-Id: Iec4195c2aefa65f59e464c83018246e17cd08173
Reviewed-on: https://go-review.googlesource.com/c/go/+/268478
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-03-05 23:58:34 +00:00
Cherry Zhang
f901ea701d cmd/internal/goobj: store relocation type as uint16
Currently, relocation type is stored as uint8 in object files, as
Go relocations do not exceed 255. In the linker, however, it is
used as a 16-bit type, because external relocations can exceed
255. The linker has to store the extra byte in a side table. This
complicates many things.

Just store it as uint16 in object files. This simplifies things,
with a small cost of increasing the object file sizes.

               before      after
hello.o         1672        1678
runtime.a    7927784     8056194

Change-Id: I313cf44ad0b8b3b76e35055ae55d911ff35e3158
Reviewed-on: https://go-review.googlesource.com/c/go/+/268477
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>
2021-03-05 23:34:43 +00:00
John Bampton
6ba4a300d8 docs: fix spelling
Change-Id: Ib689e5793d9cb372e759c4f34af71f004010c822
GitHub-Last-Rev: d63798388e
GitHub-Pull-Request: golang/go#44259
Reviewed-on: https://go-review.googlesource.com/c/go/+/291949
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Robert Griesemer <gri@golang.org>
2021-02-24 04:11:43 +00:00
Russ Cox
4dd77bdc91 cmd/asm, cmd/link, runtime: introduce FuncInfo flag bits
The runtime traceback code has its own definition of which functions
mark the top frame of a stack, separate from the TOPFRAME bits that
exist in the assembly and are passed along in DWARF information.
It's error-prone and redundant to have two different sources of truth.
This CL provides the actual TOPFRAME bits to the runtime, so that
the runtime can use those bits instead of reinventing its own category.

This CL also adds a new bit, SPWRITE, which marks functions that
write directly to SP (anything but adding and subtracting constants).
Such functions must stop a traceback, because the traceback has no
way to rederive the SP on entry. Again, the runtime has its own definition
which is mostly correct, but also missing some functions. During ordinary
goroutine context switches, such functions do not appear on the stack,
so the incompleteness in the runtime usually doesn't matter.
But profiling signals can arrive at any moment, and the runtime may
crash during traceback if it attempts to unwind an SP-writing frame
and gets out-of-sync with the actual stack. The runtime contains code
to try to detect likely candidates but again it is incomplete.
Deriving the SPWRITE bit automatically from the actual assembly code
provides the complete truth, and passing it to the runtime lets the
runtime use it.

This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.
This CL is, however, not windows/arm64-specific.
It is cleanup meant to make the port (and future ports) easier.

Change-Id: I227f53b23ac5b3dabfcc5e8ee3f00df4e113cf58
Reviewed-on: https://go-review.googlesource.com/c/go/+/288800
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-02-19 00:02:30 +00:00
Cherry Zhang
59703d53e2 [dev.regabi] cmd/link: stop using ABI aliases if wrapper is enabled
If ABI wrappers are enabled, we should not see ABI aliases at
link time. Stop resolving them. One exception is shared linkage,
where we still use ABI aliases as we don't always know the ABI
for symbols from shared libraries.

Change-Id: Ia89a788094382adeb4c4ef9b0312aa6e8c2f79ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/290032
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
2021-02-10 15:40:37 +00:00
Than McIntosh
8e5778ed70 cmd/link: report error if builtin referenced but not defined
When the compiler refers to a runtime builtin, it emits an indexed
symbol reference in the object file via predetermined/preassigned ID
within the PkgIdxBuiltin pseudo-package. At link time when the loader
encounters these references, it redirects them to the corresponding
defined symbol in the runtime package. This redirection process
currently assumes that if a runtime builtin is referenced, we'll
always have a definition for it. This assumption holds in most cases,
however for the builtins "runtime.racefuncenter" and
"runtime.racefuncexit", we'll only see definitions if the runtime
package we're linking against was built with "-race".

In the bug in question, build passes "-gcflags=-race" during
compilation of the main package, but doesn't pass "-race" directly to
'go build', and as a result the final link combines a
race-instrumented main with a non-race runtime; this results in R_CALL
relocations with zero-valued target symbols, resulting in a panic
during stack checking.

This patch changes the loader's resolve method to detect situations
where we're asking for builtin "runtime.X", but the runtime package
read in doesn't contain a definition for X.

Fixes #42396.

Change-Id: Iafd38bd3b0f7f462868d120ccd4d7d1b88b27436
Reviewed-on: https://go-review.googlesource.com/c/go/+/267881
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-11-05 22:14:40 +00:00
Cherry Zhang
627959eb04 cmd/link: support cgo internal/linking on darwin/arm64
Cgo programs work as well. Still not enabled by default for now.

Enable internal linking tests.

Updates #38485.

Change-Id: I8324a5c263fba221eb4e67d71207ca84fa241e6c
Reviewed-on: https://go-review.googlesource.com/c/go/+/263637
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>
2020-10-20 02:25:52 +00:00
Joel Sing
15eaa870e1 cmd/link: add support for external linking on linux/riscv64
Fixes #36739

Change-Id: Id7573b343786360c72524f9f27d2a8f08d379cf3
Reviewed-on: https://go-review.googlesource.com/c/go/+/243517
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-18 08:30:18 +00:00
Jeremy Faller
91e4d2d57b [dev.link] Merge branch 'master' into dev.link
2 conflicts, that make sense.
	src/cmd/internal/obj/objfile.go
	src/cmd/link/internal/loader/loader.go

Change-Id: Ib224e2d248cb568fa1e888af79dd908b2f5e05ff
2020-09-30 18:00:58 -04:00
Cherry Zhang
66770f4b1d cmd/compile: mark type namedata symbols content-addressable
Type namedata symbols are for type/field/method names and package
paths. We can use content-addressable symbol mechanism for them.

Change-Id: I923fda17b7094c7a0e46aad7c450622eb3826294
Reviewed-on: https://go-review.googlesource.com/c/go/+/257960
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>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-09-29 17:25:24 +00:00
Cherry Zhang
af18bce87c cmd/link: consider interface conversions only in reachable code
The linker prunes methods that are not directly reachable if the
receiver type is never converted to interface. Currently, this
"never" is too strong: it is invalidated even if the interface
conversion is in an unreachable function. This CL improves it by
only considering interface conversions in reachable code. To do
that, we introduce a marker relocation R_USEIFACE, which marks
the target symbol as UsedInIface if the source symbol is reached.

binary size    before      after
cmd/compile   18897528   18887400
cmd/go        13607372   13470652

Change-Id: I66c6b69eeff9ae02d84d2e6f2bc7f1b29dd53910
Reviewed-on: https://go-review.googlesource.com/c/go/+/256797
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-09-28 21:30:01 +00:00
Cherry Zhang
3ab22052fb [dev.link] all: merge branch 'master' into dev.link
Clean merge.

Change-Id: Ib773b0bc00fd99d494f9331c3613bcc8285e48e3
2020-09-11 12:07:44 -04:00
Cherry Zhang
83ed734df0 cmd/link: pre-resolve package reference
Pre-resolve package index references, so it doesn't need to do a
map lookup in every cross-package symbol reference resolution. It
increases the memory usage very slightly (O(# imported packages)).

Change-Id: Ia76c97ac51f1c2c2d5ea7ae34853850ec69ef0a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/253604
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-09-09 15:15:33 +00:00
Jeremy Faller
5402d40d5b [dev.link] cmd/link: fix memory growth on dev.link
CL 247399 caused memory growth in the linker. Fix this by adjusting how
we preallocate the number of symbols we'll need.

cmd/compile (Darwin), alloc/op:
Loadlib_GC                   33.5MB ± 0%    27.3MB ± 0%

Change-Id: I34997329ea4412716114df97fc9dad6ad0c171ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/249024
Run-TryBot: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-09-03 15:50:46 +00:00
Jeremy Faller
5387cdcb24 [dev.link] cmd/link, cmd/compile: create content addressable pcdata syms
Switch pcdata over to content addressable symbols. This is the last
step before removing these from pclntab_old.

No meaningful benchmarks changes come from this work.

Change-Id: I3f74f3d6026a278babe437c8010e22992c92bd89
Reviewed-on: https://go-review.googlesource.com/c/go/+/247399
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-08-13 16:47:08 +00:00
Cherry Zhang
27e3778793 [dev.link] cmd: remove "2", another round
Rename the goobj2 package to goobj.

Change-Id: Iff97b5575cbac45ac44de96b6bd9d555b9a4a12a
Reviewed-on: https://go-review.googlesource.com/c/go/+/246444
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2020-08-11 18:32:23 +00:00
Jeremy Faller
9bdaf99966 [dev.link] use per package filenames to build pclntab
In order to prevent renumbering of filenames in pclntab generation, use
the per-package file list (previously only used for DWARF generation) as
file-indices. This is the largest step to eliminate renumbering of
filenames in pclntab.

Note, this is probably not the final state of the file table within the
object file. In this form, the linker loads all filenames for all
objects. I'll move to storing the filenames as regular string
symbols,and defaulting all string symbols to using the larger hash value
to make generation of pcln simplest, and most memory friendly.

Change-Id: I23daafa3f4b4535076e23100200ae0e7163aafe0
Reviewed-on: https://go-review.googlesource.com/c/go/+/245485
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2020-08-10 16:55:06 +00:00
Cherry Zhang
db924fd99e [dev.link] cmd/compile, cmd/link: generate itablink at link time
Currently, at compile time, for each itab symbol, we create an
"itablink" symbol which holds solely the address of the itab
symbol. At link time, all the itablink symbols are grouped
together to form the itablinks slice.

This CL removes the itablink symbols, and directly generate the
itablinks slice in the linker. This removes a number of symbols,
which are dupOK and generally have long names. And also removes
a special handling of itablink symbols in the deadcode pass which
iterates through all symbols.

Change-Id: I475c3c8899e9fbeec9abc7647b1e4a69aa5c3c5a
Reviewed-on: https://go-review.googlesource.com/c/go/+/245901
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-08-03 21:13:25 +00:00
Cherry Zhang
f204ca3051 [dev.link] cmd/link: drop hash maps after loading
The hash maps are used to deduplicate hashed symbols. Once we
loaded all the symbols, we no longer need the hash maps. Drop
them.

Linking cmd/compile,

name         old live-B     new live-B     delta
Loadlib_GC      13.1M ± 0%     11.3M ± 0%   -13.62%  (p=0.008 n=5+5)

Change-Id: I4bb1f84e1111a56d9e777cd6a68f7d974b60e321
Reviewed-on: https://go-review.googlesource.com/c/go/+/245721
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-08-03 21:12:56 +00:00
Cherry Zhang
cecb7a1cf3 [dev.link] cmd/compile, cmd/link: make itab symbols content-addressable
Extend the content-addressable symbol mechanism to itab symbols.
Itab symbols require global uniqueness (as at run time we compare
pointers), so it needs to be reliably deduplicated. Currently the
content hash depends on symbol name expansion, so we can only do
this when all Go packages are built with know package paths. Fall
back to checking names if any Go package is built with unknown
package path.

Change-Id: Icf5e8873755050c20e5fc6549f6de1c883254c89
Reviewed-on: https://go-review.googlesource.com/c/go/+/245719
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-08-03 21:12:28 +00:00
Cherry Zhang
69748f0ce4 [dev.link] cmd/compile, cmd/link: reference type symbol of defined type by index
The type descriptor symbol of a defined (named) type (and pointer
to it) is defined only in the package that defines the type. It
is not dupOK, unlike other type descriptors. So it can be
referenced by index. Currently it is referenced by name for
cross-package references, because the index is not exported and
so not known to the referencing package.

This CL passes the index through the export data, so the symbol
can be referenced by index, and does not need to be looked up by
name. This also makes such symbol references consistent: it is
referenced by index within the defining package and also cross-
package, which makes it easier for content hashing (in later CLs).

One complication is that we need to set flags on referenced
symbols (specifically, the UsedInIface flag). Before, they are
non-package refs, which naturally carry flags in the object file.
For indexed refs, we currently don't put their flags in the
object file. Introduce a new block for this.

Change-Id: I8126f8e318ac4e6609eb2ac136201fd6c264c256
Reviewed-on: https://go-review.googlesource.com/c/go/+/245718
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-08-03 21:11:33 +00:00
Jeremy Faller
89cf569a45 [dev.link] move FuncID creation into the compiler/assembler
Leaving creation of the funcID till the linker requires the linker to
load the function and file names into memory. Moving these into the
compiler/assembler prevents this.

This work is a step towards moving all func metadata into the compiler.

Change-Id: Iebffdc5a909adbd03ac263fde3f4c3d492fb1eac
Reviewed-on: https://go-review.googlesource.com/c/go/+/244024
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
2020-08-03 17:56:50 +00:00
Cherry Zhang
847b9be3f6 [dev.link] cmd/link: make symbol attribute setting more reliable
For dupOK symbols, their attributes should be OR'd. Most of the
attributes are expected to be set consistently across multiple
definitions, but UsedInIface must be OR'd, and for alignment we
need to pick the largest one. Currently the attributes are not
always OR'd, depending on addSym returning true or false. This
doesn't cause any real problem, but it would be a problem if we
make type descriptor symbols content-addressable.

This CL removes the second result of addSym, and lets preloadSyms
always set the attributes. Also removes the alignment handling on
addSym, handles it in preloadSyms only.

Change-Id: I06b3f0adb733f6681956ea9ef54736baa86ae7bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/245720
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-07-31 21:02:26 +00:00
Jeremy Faller
6ac9914383 [dev.link] create runtime.funcnametab
Move the function names out of runtime.pclntab_old, creating
runtime.funcnametab.  There is an unfortunate artifact in this change in
that calculating the funcID still requires loading the name. Future work
will likely pull this out and put it into the object file Funcs.

ls -l cmd/compile (darwin):
  before: 18524016
  after:  18519952

The difference in size can be attributed to alignment in pclntab_old.

Change-Id: Ibcbb230d4632178f8fcd0667165f5335786381f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/243223
Reviewed-by: Austin Clements <austin@google.com>
2020-07-31 13:55:07 +00:00
Cherry Zhang
4a92371291 [dev.link] cmd/link: remove "2", another round
Rename Reloc2 to Reloc, At2 to At, Aux2 to Aux.

Change-Id: Ic98d83c080e8cd80fbe1837c8f0aa134033508ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/245578
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-07-30 16:37:23 +00:00
Cherry Zhang
80b287fd28 [dev.link] cmd/link: remove loader.Reloc
We have Reloc and Reloc2. Reloc2 is the better approach and most
code uses Reloc2. There are still uses of Reloc. This CL migrates
them to Reloc2, and removes Reloc.

Change-Id: Id5f6a6019e1e044add682d05e70ebb1548ec58d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/245577
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-07-30 16:37:04 +00:00