Expand the methods for the FuncInfo helper, to support reading the
contents of an object file FuncInfo aux symbol using the new style
(that is to say, incrementally and without allocating slices to hold
the various bits).
Change-Id: I953d72c4a53f98c840e6b25b08fd33dc4a833dd5
Reviewed-on: https://go-review.googlesource.com/c/go/+/227585
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Implement text address assignment and trampoline generation using
the loader.
Note: the trampoline insertion part doesn't actually work. It
also needs to propagate Aux symbols for external symbols in
LoadFull. But it won't be needed after converting pclntab
generation, so I'll leave it out for now. This could break
linking large binaries on PPC64 and ARM.
Change-Id: Ie46a35b25d7c027983dd877207cfa8f67c32530b
Reviewed-on: https://go-review.googlesource.com/c/go/+/227482
Reviewed-by: Than McIntosh <thanm@google.com>
SymFile, derived from sym.Symbol.File, is supposed to return the
package path, instead of the file name (arguably the name is
confusing). Make it so, and rename it to SymPkg.
Change-Id: I67bcd12f67cea271f2a2ce3c5724e5d228f5b2f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/227481
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Remove some extra sanity-checking code from the loader's RelocVariant
method, since it was yielding a slowdown of 1-2% linking kubernetes
hyperkube (once again a reminder that relocation processing is a very
performance-sensitive part of the linker).
Change-Id: Ifbc0662f3f96c5f54131103ce6f7439ecfb9b9dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/227477
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Add support to the loader for getting/setting the 'variant' property
of a symbol relocation. The variant property handles unusual or
infrequently used relocations that have both a type and a variant of
that type (this is needed for S390).
In the sym.Symbol world, a relocation variant is a field on the
'relocExt' extension that is part of sym.Reloc. In this new
implementation for the loader, reloc variants are stored in a side
table (a map) in the loader, and accessed via loader methods.
Change-Id: I62bf54ae7ff6d500c0ea8d2dbe759b2431087378
Reviewed-on: https://go-review.googlesource.com/c/go/+/227018
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This ports CL 226997 to the dev.link branch.
- The assembler part and old object file writing are unchanged.
- Changes to cmd/link are applied to cmd/oldlink.
- Add alignment field to new object files for the new linker.
Change-Id: Id00f323ae5bdd86b2709a702ee28bcaa9ba962f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/227025
Reviewed-by: Than McIntosh <thanm@google.com>
Along the line with Reloc and Aux, use new-style accessors for
the Sym type. They avoid reading unnecessary fields, and also
look nicer (to me).
Change-Id: Ie37c5149a6edb2184724b3dfa26952015e74c085
Reviewed-on: https://go-review.googlesource.com/c/go/+/226798
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
The Count field in Relocs type is always equal to len(rs). Unify
them.
Change-Id: Ic77288ea58b61a98482b218e051d81047d0ddd88
Reviewed-on: https://go-review.googlesource.com/c/go/+/226717
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Store external relocations in (almost) the same format as the Go
objects, so we can handle them more uniformly.
There is a small speedup:
(linking cmd/compile)
Deadcode 67.8ms ± 3% 61.1ms ± 3% -9.94% (p=0.008 n=5+5)
Dostkcheck 41.2ms ± 2% 38.8ms ± 3% -5.99% (p=0.008 n=5+5)
Change-Id: I8616e10b26235904201d6c9465f5ae32a49c9949
Reviewed-on: https://go-review.googlesource.com/c/go/+/226365
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add support for migrating over the symbol Dynid property
when converting loader.Sym symbols to sym.Symbol.
Change-Id: Icc3b91b4adcae6f2ede7d915bb674cc206025217
Reviewed-on: https://go-review.googlesource.com/c/go/+/226360
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This gives some small speedup:
(linking cmd/compile)
Loadlibfull 77.8ms ± 6% 68.6ms ± 5% -11.88% (p=0.008 n=5+5)
Also convert some Relocs.At to At2, which should have been done
earlier.
Change-Id: I2a66aeb5857234c6e645e1b23380149cffc8221f
Reviewed-on: https://go-review.googlesource.com/c/go/+/226363
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
When using the new(old) linker but an old(new) object file is
found, give a better error message.
Change-Id: I94786f1a4b527c15c4f5b00457eab60d215a72a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/225457
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Add accessor methods to get at the symbol {plt,got} value for
PE symbols. Fix a bug in the loaders SetPlt/SetGot methods.
Change-Id: I975bd6b86122622b206487c8798f8290ecd25a57
Reviewed-on: https://go-review.googlesource.com/c/go/+/225199
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Currently, in LoadFull we migrate a symbol's Value to sym.Symbol
only for external symbols. And symbol's Align is not migrated at
all. As we move LoadFull forward, there are already places where
we set symbol's Value and Align (e.g. in doelf). Migrate them
correctly.
Currently I think we only set them on external symbols, but as
we move forward I think we'll need to set them on Go symbols as
well.
Change-Id: I63e97e38fc08b653ba9faefe15697944faf21bed
Reviewed-on: https://go-review.googlesource.com/c/go/+/225658
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Rewrite setupdynexp to work with loader.Sym, and move the call to it
before the body of loadlibfull. After loadlibfull is complete,
construct the old *sym.Symbol version of dynexp, since not all all
clients that access this list are converted to the loader APIs.
Change-Id: I347d24958e2f3e2332fbe33f2eb6ec25cc126bdb
Reviewed-on: https://go-review.googlesource.com/c/go/+/224382
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Update PropagateLoaderChangesToSymbols so that it no longer requires
a sym.Symbols pointer. The intent is to generalize it a little to
allow it to be used in more than just linker Dwarf generation.
Change-Id: I9bddc5d39839eacd9113c945bb59d2873c0b088c
Reviewed-on: https://go-review.googlesource.com/c/go/+/224381
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
On AIX, when external linking, we need to change the function
names to start with a dot and make function descriptors with the
names without the dot. Currently this is done through symbol
renaming, which is not friendly for switching to the loader.
In this CL we use symbol's external name for this. This allows us
to get rid of symbol renaming.
Change-Id: If72602d17e96f0339fdac2e2321f1edfb292b5f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/224940
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Use symbol's Extname, instead of symbol renaming, for the mangled
names.
The old symbol Rename has an interesting logic of "merging"
symbols, when a symbol is renamed to the name of an existing
symbol. It turns out that this is needed for linking against
shared libraries, where the Go object has a reference to a symbol
with the original name, and the shared libary provides a symbol
under the mangled name. Implement this logic with the loader.
Change-Id: Ib95d7a9c93a52f8e02f4a51ac67240d6ebfc1c6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/224939
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Set the "local" attribute on object file loader symbols during preload,
as opposed to the current strategy of only propagating the local attr
when we convert to sym.Symbols.
Change-Id: I18965e2fdaa9a0b9315d95466d17d9f41aa40a45
Reviewed-on: https://go-review.googlesource.com/c/go/+/224379
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>
Add SymDynid and SetSymDynid methods to the loader. This symbol
property is currently backed by a map.
Change-Id: Iaf86b1d8aaa775fa102fadea30394eb8a670e0e2
Reviewed-on: https://go-review.googlesource.com/c/go/+/224378
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>
When fixing up relocations in PropagateLoaderChangesToSymbols, don't
reallocate the target sym.Symbol relocation slice if it already has
the desired size (this gets rid of some unneeded allocations).
Change-Id: I05287772c18cab861c2df805fa9497103fb00dcc
Reviewed-on: https://go-review.googlesource.com/c/go/+/224420
Reviewed-by: Jeremy Faller <jeremy@golang.org>
This patch moves the compiler and linker away from the current scheme
used to generate file references in DWARF subprogram dies.
Up until now the scheme has been to have the compiler emit a special
relocation on a DIE file reference that points to the file symbol in
question. The linker then reads this relocation and updates the addend
to the index of the appropriate file in the line table of the
compilation unit of the DIE (the linker emits the comp unit file
table, so it knows at that point what number use). The drawback of
this scheme is that it requires a lot of relocation processing.
With this patch, we switch to having the compiler emit the file index
directly, and then have the linker use the compiler-generated file
table to emit the line table file section (no renumbering, no
relocations, etc).
Change-Id: Id4fbe67b28a64200a083e3c5ea358dbe091ec917
Reviewed-on: https://go-review.googlesource.com/c/go/+/223318
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Switch the primary subprogram die DWARF symbol emitted by the compiler
from named+dupOK to anonymous aux. This should help performance wise
by not having to add these symbols to the linker's symbol name lookup
tables.
Change-Id: Idf66662b8bf60b3dee9a55e6cd5137b24a9f5ab6
Reviewed-on: https://go-review.googlesource.com/c/go/+/223669
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Minor cleanup of symbol attributes. Specifically:
- if a symbol originally begins life as an object file symbol,
then is converted to external in cloneToExternal, use the
previously recorded object file index for the sym to figure
out if it has read-only data (in the case that there is no
entry for it in the map in question).
- remove SetAttrShared; only the loader should be populating this
attribute at symbol creation (it never gets updated later)
- remove unused copyAttributes() method
- comment fixes
Change-Id: Iac7bc6ac310ec89bfe733ddc783970d2a8017478
Reviewed-on: https://go-review.googlesource.com/c/go/+/223667
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
They used to be different at some point, but now AddExtSym and
LookupOrCreateSym are identical. Remove one.
Change-Id: I299444d987e32a7f43915b3c1bbcc5ae906e9b6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/223977
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Following the previous CLs, do the same for aux symbols. This has
some small speedup:
(linking cmd/compile)
Dostkcheck 41.0ms ± 1% 38.6ms ± 1% -6.00% (p=0.008 n=5+5)
Change-Id: Id62b2fc9e4ef1be92e60e4c03faec0a953eee94e
Reviewed-on: https://go-review.googlesource.com/c/go/+/222303
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
In CL 222244, we store external relocations in the same format as
Go object files. In Go object file format, the relocation type is
a uint8. However, for external relocations the type may not
always fit in a uint8. Truncating it will result in a bad
relocation. Fix this by storing the external reloc type on the
side. (An alternative is to extend the Go object file format to
use a uint16, but it is not necessary for Go relocations and
will waste some binary size.)
Fix ARM build.
Change-Id: I343e240d38ee0e2cc91e0e7754d03b19b525a014
Reviewed-on: https://go-review.googlesource.com/c/go/+/223338
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
There is a small speedup:
(linking cmd/compile)
name old time/op new time/op delta
Deadcode 57.1ms ± 1% 53.5ms ± 1% -6.44% (p=0.008 n=5+5)
With this, we don't need a slice to read the relocations, reduce
some allocations.
name old alloc/op new alloc/op delta
Deadcode 4.16MB ± 0% 3.84MB ± 0% -7.85% (p=0.008 n=5+5)
Change-Id: Icd41c05682ba3f293a8cb9d2fe818e39d7276e5a
Reviewed-on: https://go-review.googlesource.com/c/go/+/222244
Reviewed-by: Than McIntosh <thanm@google.com>
Use a different mechanism to access relocations from the object
files, and use it in the stack bounds check pass. This shows some
speedup.
(linking cmd/compile)
Dostkcheck 76.9ms ± 1% 55.1ms ± 1% -28.36% (p=0.008 n=5+5)
Change-Id: I2ac42da515dccd64719fb557ffff6cdc69e4319b
Reviewed-on: https://go-review.googlesource.com/c/go/+/222240
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
When the compiler emits DWARF for a function F, in addition to the
text symbol for F, it emits a set of sibling or child symbols that
carry the various DWARF bits for F (for example, go.info.F,
go.ranges.F, go.loc.F, and so on).
Prior to the linker modernization work, name lookup was the way you
made your way from a function symbol to one of its child DWARF
symbols. We now have a new mechanism (aux symbols), so there is really
no need for the DWARF sub-symbols to be named or to be dupok.
This patch converts DWARF "range" and "loc" sub-symbols to be pure aux
syms: unnamed, and connected to their parent text symbol only via aux
data. This should presumably have performance benefits in that we add
fewer symbols to the linker lookup tables.
Other related DWARF sub-symbols (ex: go.line.*) will be handled in a
subsequent patch.
Change-Id: Iae3ec2d42452962d4afc1df4a1bd89ccdeadc6e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/222673
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Remove the various bits of code in the linker that patch DWARF name
attributes (rewrite "". to packagepath).
Change-Id: I29a38d680d411ccf1c1eeb760f2d15fc8ec22d90
Reviewed-on: https://go-review.googlesource.com/c/go/+/222719
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Remove a few lines of debugging trace output code left in
by accident when the final version of CL 220987 was submitted.
Change-Id: Ib84a4658194266597140a0e88a2f90f57f78cf53
Reviewed-on: https://go-review.googlesource.com/c/go/+/222299
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
This converts the second portion of DWARF-gen (dwarfGenerateDebugSyms
function and friends) to use the loader, as opposed to sym.Symbols.
Second phase is invoked as part of dodata(), which is fairly far along
in the linker, meaning that the "converted to loader.Symbol" wavefront
has not yet reached that point.
To account for this, the patch contains some shim code that runs
initially to copy back things from sym.Symbols into the loader
(notable symbol values), and then a second hook to be code after
dwarf-gen is complete to that copies the results back into the
appropriate sym.Symbols. This code is obviously temporary, but needed
for the time being.
Change-Id: I9b830b08b16480a1a5230cb52b592db1c550af18
Reviewed-on: https://go-review.googlesource.com/c/go/+/220987
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Remove references to the loader.Loader's "ocache" field, which is no
longer being used the way it was. Add in a new field for object index
to the oReader type.
Change-Id: Icae6c54dbbdbbfa63ab9de3e4dc09e10abd57ee3
Reviewed-on: https://go-review.googlesource.com/c/go/+/222063
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Add a new loader method PatchDWARFName to patch up live DWARF function
DIEs during DWARF generation. This is needed to handle subprogram DIE
symbols emitted by the assembler, which still embeds "". package
tokens into the data sections of these dies.
Note: this is expected to be a temporary hack, as we are going to
transition the assembler to do the patching itself when passed the
"-p" option (once this happens the plan is to toss all of the various
PatchDWARFName helpers).
Change-Id: Id689a751f08d7f4c096c4ac2f99991f9641959e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/220986
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
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
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
The type symbols were always loaded in LoadFull, as the old
sym.Symbol-based DWARF generation needs them to present. Now we
have converted the DWARF type generation pass, which uses the
loader symbols directly. No need to load the type symbols if they
are not live.
This reduces loaded symbols by ~18% for cmd/compile.
Change-Id: Ic1f6fcdff845f3c62784d05ad716b1742f249481
Reviewed-on: https://go-review.googlesource.com/c/go/+/222018
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Export loader's bitmap. As more things converted to new style,
I think it may be not uncommon to have bitmaps for symbols used
outside of the loader.
Change-Id: Ida68dac87988957a29985143121d781296820fcf
Reviewed-on: https://go-review.googlesource.com/c/go/+/220980
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Add accessors for fields of FuncInfo, so we don't have to read
the whole FuncInfo.
TODO: explore/experiment with an alternative idea -- splitting
FuncInfo to separate Aux symbols.
Change-Id: Ie4bc2613fd76d08fc63fd86956802920da63dd2f
Reviewed-on: https://go-review.googlesource.com/c/go/+/220979
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Move NoSplit flag from FuncInfo to symbol flag, so this can be
accessed easily without reading the FuncInfo.
The CFunc flag is never used. Remove.
Change-Id: I8bf4fcb2f209434bb90ccc4987a4c3f28f003323
Reviewed-on: https://go-review.googlesource.com/c/go/+/220058
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
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>
