tree 4bdd72e88d7e913152139f7d9767a781d5f3a823
parent a92fe49002e8f0a348265fef12d9ee4af50b4f77
author Tess Strickland <sstrickl@google.com> 1626161965 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1626161965 +0000

[vm] Delay symbol table creation further.

Create all symbol table-related sections after all other sections, right
before section re-ordering. Also remove the need to keep fields in the
Elf object for most of these sections, only keeping fields for the
static symbol table and the dynamic table, which handles updates
and finalization for the dynamic symbol table.

Reworks symbols so that they are stored in a growable array in the
symbol table instead of as separately allocated objects. Since this
disallows constant fields in Symbol objects due to the need for a copy
constructor, initialize the offset of symbols with the section-relative
offset. This can be adjusted to a snapshot-relative offset after
section memory offsets are computed.

Instead of updating indices and offsets by individually looking up
symbols via their name, just create a map from section indices to new
section indices (for index updates) or to memory offsets (for offset
adjustment) and iterate over all the symbols, applying the map
appropriately.

Move non-PT_LOAD, non-PT_PHDR segment creation into
OrderSectionsAndCreateSegments.

TEST=Refactoring, so existing ELF-based tests.

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-dwarf-linux-product-x64-try
Change-Id: Ic22f1bf3ab0b00ff3e73c431f92209526e787927
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/206220
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>