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>
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Reviewed-by: Than McIntosh <thanm@google.com>
types2.Constraint() returns the top-level constraint type, including any
unions or other interface elements. Because of that, we needed to
add/fix some code in the type substituter and generic type instantiater
in the importer to deal with unions and non-method members of an
interface. Also, NewUnion was not correctly setting the HasTParam flag.
I also added a better error message when a symbol is not found in
(*deadcodePass).decodeIfaceMethod().
Change-Id: Id3668dc596dce63690fa05a9e5e42295b5e2bbb5
Reviewed-on: https://go-review.googlesource.com/c/go/+/340670
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
In the deadcode path we mark runtime.unreachableMethod symbol,
which is a special symbol used for redirecting unreachable
methods. Currently this code is conditioned on not -linkshared.
This is wrong. It should be marked with -linkshared mode as well.
In fact, -linkshared should only affect the entry symbol. Change
the code accordingly.
Change-Id: I252abf850212a930f275589ef0035a43e52cb9cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/319893
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Reviewed-by: Jeremy Faller <jeremy@golang.org>
The go/build package needs access to this configuration,
so move it into a new package available to the standard library.
Change-Id: I868a94148b52350c76116451f4ad9191246adcff
Reviewed-on: https://go-review.googlesource.com/c/go/+/310731
Trust: Russ Cox <rsc@golang.org>
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Reviewed-by: Jay Conrod <jayconrod@google.com>
Currently, setCgoAttr populates the cgo_export_{static,dynamic} maps
with symbol names of exported symbols, which are then re-looked-up by
deadcode and setupdynexp, which in turn puts the re-looked-up symbols
in ctxt.dynexp. setCgoAttr already looked up the Syms, so simplify all
of this by making setCgoAttr populate ctxt.dynexp directly and
eliminating the cgo_export_{static,dynamic} maps. Recording Syms
directly also sets us up to use correct symbol versions for these
exports, rather than just assuming version 0 for all lookups.
Since setupdynexp doesn't really do any "setting up" of dynexp any
more with this change, we fold the remaining logic from setupdynexp
directly into addexport, where it has better context anyway. This also
eliminates a sorting step, since we no longer do a non-deterministic
map iteration to build the dynexp slice.
For #40724.
Change-Id: I3e1a65165268da8c2bf50d7485f2624133433260
Reviewed-on: https://go-review.googlesource.com/c/go/+/309340
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Reviewed-by: Than McIntosh <thanm@google.com>
When converting a type T to a non-empty interface I, we build the
itab which contains the code pointers of the methods. Currently,
this brings those methods live (if the itab is live), even if the
interface method is never used. This CL changes the itab to use
weak references, so the methods can be pruned if not otherwise
live.
Fixes#42421.
Change-Id: Iee5de2ba11d603c5a102a2ba60440d839a7f9702
Reviewed-on: https://go-review.googlesource.com/c/go/+/268479
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This moves all remaining GOEXPERIMENT flags into the objabi.Experiment
struct, drops the "_enabled" from their name, and makes them all bool
typed.
We also drop DebugFlags.Fieldtrack because the previous CL shifted the
one test that used it to use GOEXPERIMENT instead.
Change-Id: I3406fe62b1c300bb4caeaffa6ca5ce56a70497fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/302389
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Reviewed-by: Matthew Dempsky <mdempsky@google.com>
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>
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Reviewed-by: Jeremy Faller <jeremy@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
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This matches the prints that deadcode prints later
as the algorithm progresses under -v=2.
It helps to see the initial conditions with -v=2 as well.
Change-Id: I06ae86fe9bd8314d003148f3d941832c9b10aef1
Reviewed-on: https://go-review.googlesource.com/c/go/+/288817
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
In the linker's deadcode pass we decode type symbols for
interface satisfaction analysis. When linking against Go shared
libraries, the type symbol may come from a shared library, so it
doesn't have data in the current module being linked, so we cannot
decode it. We already have code to skip DYNIMPORT symbols. However,
this doesn't actually work, because at that point the type symbols'
names haven't been mangled, whereas they may be mangled in the
shared library. So the symbol definition (in shared library) and
reference (in current module) haven't been connected.
Skip decoding type symbols of type Sxxx (along with DYNIMPORT)
when linkShared.
Note: we cannot skip all type symbols, as we still need to mark
unexported methods defined in the current module.
Fixes#44031.
Change-Id: I833d19a060c94edbd6fc448172358f9a7d760657
Reviewed-on: https://go-review.googlesource.com/c/go/+/288496
Trust: Cherry Zhang <cherryyz@google.com>
Trust: Than McIntosh <thanm@google.com>
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runtime.buildVersion and runtime.modinfo are referenced in the
.go.buildinfo section, therefore reachable. They should normally
be reachable from the runtime. Just make it explicit, in case.
Change-Id: I60ff3132e0bbb690f4a3cba8bb18735921fbe951
Reviewed-on: https://go-review.googlesource.com/c/go/+/261637
Trust: Cherry Zhang <cherryyz@google.com>
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Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Currently, in the linker's deadcode pass, when an interface type
is live, the linker thinks all its methods are live, and uses
them to match methods on concrete types. The interface method may
never be used, though.
This CL changes it to only keep used interface methods, for
matching concrete type methods. To do that, when an interface
method is used, the compiler generates a mark relocation. The
linker uses the marker relocations to mark used interface
methods, and only the used ones.
binary size before after
cmd/compile 18887400 18812200
cmd/go 13470652 13470492
Change-Id: I3cfd9df4a53783330ba87735853f2a0ec3c42802
Reviewed-on: https://go-review.googlesource.com/c/go/+/256798
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
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>
In CL 231397, we stopped marking symbols' GoType reachable in
general, but not when -linkshared. It was left as a TODO. This CL
addresses it.
The problem was that the type names are mangled in the shared
library, so we need to mangle the name consistently in the
executable as well (regardless of whether the symbol is reachable
or not), so that the GCProg generation code can find the
corresponding symbol from the shared library.
Change-Id: I1040747402929a983ec581109f1681a77893682e
Reviewed-on: https://go-review.googlesource.com/c/go/+/255964
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The linker prunes methods that are not directly reachable if the
receiver type is never converted to interface. A type can be
converted to interface using reflection through other types.
The linker already takes this into consideration but it missed
the case that the intermediate is a method descriptor. Handle
this case.
Change-Id: I590efc5da163c326db8d43583908a2ef67f65d9d
Reviewed-on: https://go-review.googlesource.com/c/go/+/255858
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Reviewed-by: Jeremy Faller <jeremy@golang.org>
In the deadcode pass, a type symbol may be marked twice, one
without UsedInIface, one with. For the second time, don't
update the Reachparent graph, so it only records the path of
the first time the symbol is reached. This ensures the
Reachparent graph is acyclic.
TODO: add a test. (This only affects GOEXPERIMENT=fieldtrack)
Change-Id: I68e8a1a69c3830bc8aee5df946151dc22dcb2b29
Reviewed-on: https://go-review.googlesource.com/c/go/+/254297
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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>
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>
Currently, a method of a reachable type is live if it matches a
method of a reachable interface. In fact, we only need to retain
the method if the type is actually converted to an interface. If
the type is never converted to an interface, there is no way to
call the method through an interface method call (but the type
descriptor could still be used, e.g. in calling
runtime.newobject).
A type can be used in an interface in two ways:
- directly converted to interface. (Any interface counts, as it
is possible to convert one interface to another.)
- obtained by reflection from a related type (e.g. obtaining an
interface of T from []T).
For the former, we let the compiler emit a marker on the type
descriptor symbol when it is converted to an interface. In the
linker, we only need to check methods of marked types.
For the latter, when the linker visits a marked type, it needs to
visit all its "child" types as marked (i.e. potentially could be
converted to interface).
This reduces binary size:
cmd/compile 18792016 18706096 (-0.5%)
cmd/go 14120572 13398948 (-5.1%)
Change-Id: I4465c7eeabf575f4dc84017214c610fa05ae31fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/237298
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Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Instead of using container/heap package, implement a simple
specialized heap algorithm for the work queue in the deadcode
pass, to avoid allocations and function pointer calls.
Linking cmd/compile,
name old time/op new time/op delta
Deadcode_GC 59.8ms ± 4% 42.2ms ± 4% -29.45% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
Deadcode_GC 3.53MB ± 0% 2.10MB ± 0% -40.57% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Deadcode_GC 187k ± 0% 8k ± 0% -95.48% (p=0.008 n=5+5)
Change-Id: Ibb21801d5b8e4a7eaf429856702e02720cd1772f
Reviewed-on: https://go-review.googlesource.com/c/go/+/236565
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Currently, in the deadcode pass, when checking whether a defined
method satisfies an interface, it compares the string
representation of the defined method and the interface method.
In fact, it can simply compare the method name and the type
descriptor (as we do in runtime). Make it so.
Change-Id: Ideb2b2410e5eedcd20ac31e3af41f5499fc90225
Reviewed-on: https://go-review.googlesource.com/c/go/+/236564
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Reviewed-by: Than McIntosh <thanm@google.com>
CL 231397 is submitted too fast... Expand the comment to make it
a little clearer.
Change-Id: Ica9737aa7b51f97320bab74457388dcab8188370
Reviewed-on: https://go-review.googlesource.com/c/go/+/231597
Reviewed-by: Austin Clements <austin@google.com>
A symbol being reachable doesn't imply its type descriptor is
needed. Don't mark it.
If the type is converted to interface somewhere in the program,
there will be an explicit use of the type descriptor, which
will make it marked.
A println("hello") program before and after
-rwxr-xr-x 1 cherryyz primarygroup 1259824 Apr 30 23:00 hello
-rwxr-xr-x 1 cherryyz primarygroup 1169680 Apr 30 23:10 hello
Updates #38782.
Updates #6853.
Change-Id: I88884c126ce75ba073f1ba059c4b892c87d2ac96
Reviewed-on: https://go-review.googlesource.com/c/go/+/231397
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Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
And remove "2" from some function names.
Change-Id: Ibf1089970d849a42f53976064ceb9ade20bf6eba
Reviewed-on: https://go-review.googlesource.com/c/go/+/231017
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It is no longer needed as we have converted the fieldtrack pass
to using the loader.
Also free loader.Reachparent after we are done with it.
Change-Id: Ibc4b29f282e1e4aea363a1b549755e31f84b0295
Reviewed-on: https://go-review.googlesource.com/c/go/+/229322
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deadcode's been completely replaced. Make its death official.
Change-Id: I85f1e3968463f216b8bce2fb7217c3b51641939f
Reviewed-on: https://go-review.googlesource.com/c/go/+/229002
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Reviewed-by: Cherry Zhang <cherryyz@google.com>
Currently we only check for reflect.Value.Method. And
reflect.Value.MethodByName is covered since it calls
reflect.Value.Method internally. But it is brittle to rely on
implementation detail of the reflect package. Check for
MethodByName explicitly.
Change-Id: Ifa8920e997524003dade03abc4fb3c4e64723643
Reviewed-on: https://go-review.googlesource.com/c/go/+/228881
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Update the comment to be in sync with the code.
Change-Id: I19586767a37347c4da1b4d3f7c6dc6cc2292a90f
Reviewed-on: https://go-review.googlesource.com/c/go/+/228877
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
lib.Textp was used for text address assignment and trampoline
insertion. Now that it has been converted to using the loader,
no need to populate lib.Textp.
Port the logic of canonicalizing dupok symbol's package to the
loader.
unit.Textp was used for DWARF generation, which has also been
converted to using the loader.
Change-Id: I22d4dd30a52a29dd5b1b7b795d43a19f6215e4ac
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Change the loader method AssignTextSymbolOrder to return a slice of
all reachable textp symbols, since it will be needed in second-phase
DWARF gen.
Change-Id: Iaf16ee9cf0d5266aeb0d3df596e8117263b35d8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/220985
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Reviewed-by: Jeremy Faller <jeremy@golang.org>
Converts the portion of DWARF generation that deals with creation of
type DIEs and constant DIEs to use the new loader interfaces. Creation
of subprogram DIE and compilation unit DIE content still operates on
sym.Symbols at the moment, and happens much later in the linker.
The new code for type DIE generation is gated/guarded by the linker
flag "-newdw", which currently defaults to true. At some point in the
near future this flag should be removed, but it is handy for triage at
the moment.
This patch also includes shim code designed to run after loadlibfull()
that walks through the DIE chains and to converts loader.Sym
references back into sym.Symbol references for the remainder of the
compilation, since the second phase of DWARF has not yet been
converted.
Change-Id: I681a00fb8a1f3c37884a79b373d86411332e07c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/208230
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
In sym.Library and sym.CompilationUnit there are slices of *sym.Symbol
pointer that hold text symbols contained in the unit lib. To support
DWARF generation with new loader, add equivalent slices that hold
loader.Sym values for functions in scope. This will be needed if at
some point we push the sym.Symbol creation "wavefront" beyond dwarf
gen.
This patch also insures that live host object symbols are added to the
context Textp2 slice, since they would not make it on otherwise.
[NB: not sure if this is the best way to do this.]
Change-Id: I4f440e12cebc525b1e37082ad39cf7338aeb6b99
Reviewed-on: https://go-review.googlesource.com/c/go/+/208231
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Reviewed-by: Jeremy Faller <jeremy@golang.org>
There are more cleanups to do, but I want to keep this CL mostly
a pure deletion.
Change-Id: I30f4891a2ea54545fd6b83041746ab65895537e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/206558
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Also a similar 'elapsed' function and its usages were deleted.
Fixes#19865.
Change-Id: Ib125365e69cf2eda60de64fa74290c8c7d1fd65a
Reviewed-on: https://go-review.googlesource.com/c/go/+/171730
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With the new object files, now we can run the deadcode pass on
indices instead of Symbol structs, so we can delay creating
Symbols after the deadcode pass. Then we only need to create
reachable symbols.
Not create Symbols in LoadNew and LoadRefs, and recombine
LoadReloc into LoadFull.
Split loadcgo into two parts: the first finds root symbols, the
second create Symbols and sets attributes. The first runs before
the deadcode pass, while the second runs after.
TODO: currently there are still symbols that are not marked
reachable but still used. This includes DWARF symbols, file
symbols, and type symbols that are referenced by DWARF symbols.
We still need to create them (conservatively).
Change-Id: I695779c9312be9d49ab1683957ac3e72e1f65a1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/199643
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Switch the deadcode pass to use indices instead of Symbol
structures when using new object file format. Delay loading
symbol relocations and contents fully after the deadcode pass.
The next step is not to create Symbol structures until deadcode
is done.
Method tracking logic hasn't been implemented. Currently, all
methods of a reachable type are live.
Change-Id: Iffcd06ff84e6e52bd9eb24d1220d94234d18ab6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/198199
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Reviewed-by: Than McIntosh <thanm@google.com>
Change some decodetype functions to operate on bytes nstead of
Symbol. This is in preparation of implementing live method
tracking in index-based deadcode pass, and reducing/eliminating
sym.Symbol in general.
Change-Id: Ia9809ad7b182884225e1bda577e8dbec0cd216c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/199077
Reviewed-by: Austin Clements <austin@google.com>
If the new object file format is used, now we load full symbol
contents after the deadcode pass, for reachable symbols only.
We still load some informations early, like relocations and the
contents of type symbols, which are used in the deadcode pass.
If we rewrite deadcode to use index directly, we could delay more
of the loading (to sym.Symbol), and perhaps delay the creation of
sym.Symbol.
TODO: internal linking with host objects doesn't work yet.
Change-Id: I7d4880e8f150e8709ffac277e62191623440e4cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/197258
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Currently we add all text symbols to ctxt.Textp at load time,
then the deadcode pass filters out unreachable ones. This CL
delays adding symbols to ctxt.Textp to the end of the deadcode
pass, where we only add reachable ones.
Change-Id: Ie83b2958f915c5aaa004b8c5ed1f1bc275f4d1db
Reviewed-on: https://go-review.googlesource.com/c/go/+/197257
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Remove linker reading and processing of automs (no longer needed, now
that the compiler is emitting R_USETYPE relocations on functions). So
as to avoid changing the object file format, the object still contains
a count of automs, but this count is required to be zero.
Updates #34554.
Change-Id: I10230e191057c5c5705541eeb06f747d5f73c42d
Reviewed-on: https://go-review.googlesource.com/c/go/+/197500
Reviewed-by: Jeremy Faller <jeremy@golang.org>
As we move the debug_line generation into the compiler, we need to
upgrade the notion of compilationUnit to not just be on a per package
basis. That won't be the case as it will be impossible for all
compilationUnits to have the same set of files names used to build the
debug_lines table. (For example, assembled files in a package don't know
about any files but themselves, so the debug_lines table could only
reference themseves. As such, we need to break the 1:1 relationship
between compUnit and package.)
Change-Id: I2e517bb6c01de0115bbf777af828a2fe59c09ce8
Reviewed-on: https://go-review.googlesource.com/c/go/+/189618
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Instead of writing an init function per package that does the same
thing for every package, just write that implementation once in the
runtime. Change the compiler to generate a data structure that encodes
the required initialization operations.
Reduces cmd/go binary size by 0.3%+. Most of the init code is gone,
including all the corresponding stack map info. The .inittask
structures that replace them are quite a bit smaller.
Most usefully to me, there is no longer an init function in every -S output.
(There is an .inittask global there, but it's much less distracting.)
After this CL we could change the name of the "init.ializers" function
back to just "init".
Update #6853
R=go1.13
Change-Id: Iec82b205cc52fe3ade4d36406933c97dbc9c01b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/161337
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Back when the linker did code generation after dead code elimination,
it had to know that references to runtime.read_tls_fallback could be
generated at code generation time (and never appear before that). Now
that code generation is done by the compiler, the references to
runtime.read_tls_fallback are obvious in the relocations, so the
linker no longer needs special knowledge of this symbol.
Change-Id: I9813a8478e85a6a13470b2d0528db53fd33fcfdf
Reviewed-on: https://go-review.googlesource.com/c/154601
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This implements compiler and linker support for separating the
function calling ABI into two ABIs: a stable and an internal ABI. At
the moment, the two ABIs are identical, but we'll be able to evolve
the internal ABI without breaking existing assembly code that depends
on the stable ABI for calling to and from Go.
The Go compiler generates internal ABI symbols for all Go functions.
It uses the symabis information produced by the assembler to create
ABI wrappers whenever it encounters a body-less Go function that's
defined in assembly or a Go function that's referenced from assembly.
Since the two ABIs are currently identical, for the moment this is
implemented using "ABI alias" symbols, which are just forwarding
references to the native ABI symbol for a function. This way there's
no actual code involved in the ABI wrapper, which is good because
we're not deriving any benefit from it right now. Once the ABIs
diverge, we can eliminate ABI aliases.
The linker represents these different ABIs internally as different
versions of the same symbol. This way, the linker keeps us honest,
since every symbol definition and reference also specifies its
version. The linker is responsible for resolving ABI aliases.
Fixes#27539.
Change-Id: I197c52ec9f8fc435db8f7a4259029b20f6d65e95
Reviewed-on: https://go-review.googlesource.com/c/147160
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Cherry Mui
Dan Scales
Russ Cox
Austin Clements
Tao Qingyun
Brad Fitzpatrick
Jeremy Faller
Than McIntosh
nikita-vanyasin
Keith Randall