Author: Fangrui Song Date: 2020-02-27T10:59:15-08:00 New Revision: e705da06e22b12ee5d75076a2a1ae7b479a566e1
URL: https://github.com/llvm/llvm-project/commit/e705da06e22b12ee5d75076a2a1ae7b479a566e1 DIFF: https://github.com/llvm/llvm-project/commit/e705da06e22b12ee5d75076a2a1ae7b479a566e1.diff LOG: [lld][ELF] Add some release notes Reviewed By: hans Differential Revision: https://reviews.llvm.org/D75216 Added: Modified: lld/docs/ReleaseNotes.rst Removed: ################################################################################ diff --git a/lld/docs/ReleaseNotes.rst b/lld/docs/ReleaseNotes.rst index 5be348bb1894..7d8599cf1734 100644 --- a/lld/docs/ReleaseNotes.rst +++ b/lld/docs/ReleaseNotes.rst @@ -35,8 +35,60 @@ ELF Improvements * Relax MIPS ``jalr``and ``jr`` instructions marked by the ``R_MIPS_JALR`` relocation. +* For certain "undefined symbol" errors, a definition with a close spelling will be suggested. + (`D67039 <https://reviews.llvm.org/D67039>`_) +* ``extern "C"`` is suggested if an undefined reference is mangled(unmangled) while there + is a likely unmangled(mangled) definition. + (`D69592 <https://reviews.llvm.org/D69592>`_ `D69650 <https://reviews.llvm.org/D69650>`_) +* New ``-z noseparate-code``, ``-z separate-code`` and ``-z separate-loadable-segments``. + ``-z noseparate-code`` is the default, which can reduce sizes of linked binaries by up to + 3 times maxpagesize. + (`D64903 <https://reviews.llvm.org/D64903>`_ `D67481 <https://reviews.llvm.org/D67481>`_) +* ``-z force-bti`` and ``-z pac-plt`` are added for AArch64 Branch Target Identification and Pointer Authentication. + (`D62609 <https://reviews.llvm.org/D62609>`_) +* ``--fix-cortex-a8`` is added to fix erratum 657417. + (`D67284 <https://reviews.llvm.org/D67284>`_) +* ``-z force-ibt`` and ``-z shstk`` are added for Intel Control-flow Enforcement Technology. + (`D59780 <https://reviews.llvm.org/D59780>`_) +* ``PT_GNU_PROPERTY`` is added to help loaders locate the ``.note.gnu.property`` section. + It may be used by a future Linux kernel. + (`D70961 <https://reviews.llvm.org/D70961>`_) +* For ``--compress-debug-sections=zlib``, ``-O0`` and ``-O1`` enable compression level 1 + while ``-O2`` enables compression level 6. ``-O1`` (default) is faster than before. + (`D70658 <https://reviews.llvm.org/D70658>`_) +* Range extension thunks with addends are implemented for AArch64, PowerPC32 and PowerPC64. + (`D70637 <https://reviews.llvm.org/D70637>`_ `D70937 <https://reviews.llvm.org/D70937>`_ + `D73424 <https://reviews.llvm.org/D73424>`_) +* ``R_RISCV_ALIGN`` will be errored because linker relaxation for RISC-V is not supported. + Pass ``-mno-relax`` to disable ``R_RISCV_ALIGN``. + (`D71820 <https://reviews.llvm.org/D71820>`_) +* The ARM port will no longer insert interworking thunks for non STT_FUNC symbols. + (`D73474 <https://reviews.llvm.org/D73474>`_) +* The quality of PowerPC32 port has been greatly improved (canonical PLT, copy + relocations, non-preemptible IFUNC, range extension thunks with addends). + It can link FreeBSD 13.0 userland. +* The PowerPC64 port supports non-preemptible IFUNC. + (`D71509 <https://reviews.llvm.org/D71509>`_) +* lld creates a RO PT_LOAD and a RX PT_LOAD without a linker script. + lld creates a unified RX PT_LOAD with a linker script. + A future release will eliminate this diff erence and use a RO PT_LOAD and a RX PT_LOAD by default. + The linker script case will require ``--no-rosegment`` to restore the current behavior. +* GNU style compressed debug sections ``.zdebug`` (obsoleted by ``SHF_COMPRESSED``) + are supported for input files, but not for the output. + A future release may drop ``.zdebug`` support. + +Breaking changes +---------------- -* Reduced size of linked MIPS binaries. +* ``-Ttext=$base`` (base is usually 0) is no longer supported. + If PT_PHDR is needed, use ``--image-base=$base`` instead. + If PT_PHDR is not needed, use a linker script with `.text 0 : { *(.text*) }` as the first + output section description. + See https://bugs.llvm.org/show_bug.cgi?id=44715 for more information. + (`D67325 <https://reviews.llvm.org/D67325>`_) +* ``-Ttext-segment`` is no longer supported. Its meaning was diff erent from GNU ld's and + could cause subtle bugs. + (`D70468 <https://reviews.llvm.org/D70468>`_) COFF Improvements ----------------- _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits