Include the null import descriptor in the import directory size and derive
the IAT directory RVA from the first import descriptor of the start of
the .idata contribution.
Collapse COMDAT leader symbol patching to a single raw-symbol write path
and make the same-object versus cross-object symlink handling explicit.
Preserve public symbol offsets for ICF folds while avoiding cross-object
section number rewrites.
Fold section definition and contributions collection into a worker-count
task with barriers around the serial merge. Share section filtering
between both phases and keep zero-size COMDATs so offset-zero symbols
still map to a section.
Parse /DEF, /GUARD, and /SECTION switches, including DEF
handling for NAME/LIBRARY, BASE, VERSION, HEAPSIZE, STACKSIZE, EXPORTS,
and SECTIONS.
Store section directives in linker config and apply them consistently
when gathering object sections when pushing/searching image sections.
Pull load-config symbols for /GUARD without setting GUARD_CF until guard
tables are emitted.
Add coverage for DEF file parity, section directives, and guard
load-config handling.
Previously, COMDAT symlinks were assigned as each object batch was loaded.
Weak symbol replacement could later change the selected leader, leaving
objects from earlier passes with stale COMDAT leader refs. Library search
does not need symlinks to be valid, so solve this by doing a single sweep
assignment of COMDAT leaders after a fixed point is found.
Log and skip section contributions that fail to map into the linked image.
Keep a file-range-to-section-number map so compact file ranges produce the
correct DBI section numbers.
Add identical COMDAT folding using a color-refinement over foldable
read-only sections. Hash section contents, relocation targets, and target
colors until partitions stabilize, then redirect folded COMDAT symlinks
and discard duplicate sections.
Honor .llvm_addrsig via /LLVM_ADDRSIG so address-significant sections
are not folded, keep separate color space for code, unwind info, and
MSVC vftables, and update COMDAT symbol/section mapping after folding.
Add linker tests covering function folding, relocation-sensitive folds,
alignment, color-space separation, symlink chains, .llvm_addrsig,
pdata/xdata, and C++ ICF cases.
Nikita SmithandRyan Fleury