Add a new loader.Loader.ReadAuxSyms method that returns a slice
containing the ids of the aux symbols for a specified global symbol.
This is similar to the new interface recently added that allows you to
get back a slice of relocations (as opposed to making calls into the
loader for each one). This was idea suggested by Cherry. Compilebench
numbers:
name old time/op new time/op delta
LinkCompiler 1.63s ± 9% 1.57s ± 7% -3.84% (p=0.006 n=20+20)
LinkWithoutDebugCompiler 1.15s ±11% 1.11s ±11% ~ (p=0.108 n=20+20)
name old user-time/op new user-time/op delta
LinkCompiler 1.99s ± 8% 2.00s ±12% ~ (p=0.751 n=19+19)
LinkWithoutDebugCompiler 1.14s ±11% 1.19s ±21% ~ (p=0.183 n=20+20)
Change-Id: Iab6cbe18419aaa61d9cadb3f626a4515c71f2686
Reviewed-on: https://go-review.googlesource.com/c/go/+/203501
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Do a better job of reading relocations in the new deadcode pass.
Specifically, during method type processing, read relocations for the
symbol we're working on into a slice, and then pass the slice to
helper functions, as opposed to rereading relocs at each stage.
Change-Id: I95e3737ae91bb09b4da8e6ee68112ec255ceb0fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/201722
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Change the new loader to keep a note of the set of "go.itablink.*"
symbols (using a small map), and add a method that clients can use to
query whether a given global index corresponds to a "go.itablink.*"
sym. This eliminates one instance of raw symbol name reading/matching
during new deadcode, which should produce a minor speedup.
Change-Id: I5915773a3f33c16099ccd68592dbba783d909bc9
Reviewed-on: https://go-review.googlesource.com/c/go/+/201400
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Add a flag bit to mark symbols in the new object file as containing Go
type information. The use of a flag eliminates the need to do symbol
name matching as part of the new dead code elimination pass, which
should produce a minor speedup.
Change-Id: Iec8700e1139e2c4e310644c0766379865d2d6f82
Reviewed-on: https://go-review.googlesource.com/c/go/+/201399
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This CL adds basic shared library support in newobj mode. This is
not complete -- there are still tests in misc/cgo/testshared
failing. But at least a simple program works, and some tests
there pass.
Add the mechanism of loading external symbols with contents.
(Before, external symbols are always contentless.) This may
potentially be also used for other host objects.
Change-Id: I68dbf71e7949cc01ebf37ea159084e798ae16925
Reviewed-on: https://go-review.googlesource.com/c/go/+/201537
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Third change of several to update the loader API to reflect the final
consensus version of the loader API as described in Cherry's doc.
This piece:
- move objfile.Loader into its own separate package, and update
clients accordingly.
This includes a few minor cleanups, including converting a couple
of loader-related functions to methods, and privatizing some of the
loader methods such as ToGlobal/ToLocal.
Change-Id: Iae20585751a45491d8b19dcffc096aadae6bbfc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/200998
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Use the auxiliary symbol mechanism to connect the text symbol and
its associated DWARF symbols. This way, the linker can track the
DWARF symbols from the text symbol, without looking up special
names.
Currently, in the linker this is only used in the deadcode pass
to track which DWARF symbols are used and need to load. Later
passes still use name lookup for now.
Change-Id: I2fe49f3b1f0ecc1472ae8aa93907cff740022d8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/199801
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
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
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
When reflect.Type.Method is called, all exported methods from a
reachable type need to be conservatively live. When such a
function is called, the compiler sets an attribute to the
function, and the linker needs to check that attribute. Implement
this in the index-based deadcode pass.
Unify symbol flags and FuncInfo flags to make things simpler. In
particular, the deadcode pass can check the reflectMethod
attribute without reading in and decoding FuncInfo.
Change-Id: Ibb21e172f2996e899c6efa5551a29d0eca62df67
Reviewed-on: https://go-review.googlesource.com/c/go/+/200099
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This essentially replicates the logic of live method tracking and
type symbol decoding, rewritten to operate on indices instead of
Symbols.
TODO: the special handling of reflect.Type.Method has not been
implemented.
TODO: the symbol name is used too much. It ought to be a better
way to do it.
Change-Id: I860ee7a506c00833902e4870d15aea698a705dd9
Reviewed-on: https://go-review.googlesource.com/c/go/+/199078
Reviewed-by: Than McIntosh <thanm@google.com>
Update the new deadcode pass to use the revised loader interface
for querying relocations. Remove some of the previous loader relocation
methods, since they are no longer used.
Change-Id: I08cec4c05793a17698b2674068f64837a5bf4477
Reviewed-on: https://go-review.googlesource.com/c/go/+/200718
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
