Add in the hooks to SymbolBuilder and to the loader to allow
the linker to make modifications to a non-external symbol (e.g.
a sym whose index is less than loader.extStart).
The basic idea is to manufacture a new external symbol with the same
name and version, then import the old symbol's content (type, data,
relocations, etc) into the payload struct for the new symbol, and
finally redirect the name lookup tables to target the new sym for the
specified name/version.
This change is needed in order to convert over the host object loaders
to avoid use of sym.Symbol.
Change-Id: I79cd42b23794e830bbdbcbcd2c500c35c351f01f
Reviewed-on: https://go-review.googlesource.com/c/go/+/211897
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Add SymbolBuilder helper type -- this type provides a set of methods
intended to make it easy to manipulate the content of a symbol (type,
relocations, data, etc).
Change-Id: I579bf8d04650e66d33a9780a6c2347a576c94c6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/210178
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Add a mechanism for recording symbol alignment for external symbols
under the new loader scheme. Alignments is stored in a side table,
since most symbols don't wind up needing an alignment other than zero.
Change-Id: I97092481412c15eac9b9f4c29b5c273f53759562
Reviewed-on: https://go-review.googlesource.com/c/go/+/210177
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Add a new loader method SymSortSub that sorts the sub-symbols
of a given outer symbol (designed to be compatible with the
existing sym.Symbol method).
Change-Id: Icd6627b2e6d04524d657e712cfd39fda0e0e080b
Reviewed-on: https://go-review.googlesource.com/c/go/+/211297
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 a loader mechanism for recording outer/sub relationships between
symbols without falling back on sym.Symbol. Also includes a new
"PrependSub" method that provides a way to chain a sub-symbol only the
list of an outer symbol (a common operation when manipulating
outer/sub relationships in the linker).
Change-Id: I70c72356945ceec2bacdcdc25bcc352bfb6765a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/210777
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>
Add loader methods SymValue() and SetSymValue() to get/set the
value of a symbol by global index.
Change-Id: Ifc71480fc34c719ad00506d0828edf36c1a57119
Reviewed-on: https://go-review.googlesource.com/c/go/+/211302
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>
Add in a collection of new loader interfaces for getting/setting
symbol attributes, e.g. properties that would normally be part of the
sym.Symbol "Attr" field. This change also moves references to the
loaders 'reachable' bitmap behind a pair of loader methods, so that we
a consistent way of accessing symbol attributes overall. It is worth
noting that not every symbol attribute is backed by a bitmap; for some
infrequently used attributes, a map[Sym]struct{} is used instead.
Change-Id: I0010c9cd928d41b4bb6cdf45db4581e11c3c5db3
Reviewed-on: https://go-review.googlesource.com/c/go/+/210778
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>
Create loader infrastructure for constructing the payloads of external
symbols from scratch, as opposed to passing in a sym.Symbol object
containing the payload.
The general idea is that clients can use the loader to create new
external Sym's using loader.AddExtSym, and then can add
relocations/data to the new sym with symbol builder interfaces (to be
provided in an subsequent patch), as opposed to having to use
sym.Symbol.
This change preserves compatibility with the old way of doing things
(passing in sym.Symbol) via a new loader.InstallSym method. If a
client invokes this method for a specific Sym, then the loader keeps
track of this fact and uses the sym.Symbol as the backing store instead.
Also included is a small unit test for the new interfaces -- not clear
whether this really needs to be kept around long term... it was mainly
useful during initial bringup.
Change-Id: If8ab15df7b64636e56b317155dfe6d7cdfe23b71
Reviewed-on: https://go-review.googlesource.com/c/go/+/207606
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>
