| .. If you want to modify sections/contents permanently, you should modify both |
| ReleaseNotes.rst and ReleaseNotesTemplate.txt. |
| |
| =========================== |
| lld |release| Release Notes |
| =========================== |
| |
| .. contents:: |
| :local: |
| |
| .. only:: PreRelease |
| |
| .. warning:: |
| These are in-progress notes for the upcoming LLVM |release| release. |
| Release notes for previous releases can be found on |
| `the Download Page <https://releases.llvm.org/download.html>`_. |
| |
| Introduction |
| ============ |
| |
| This document contains the release notes for the lld linker, release |release|. |
| Here we describe the status of lld, including major improvements |
| from the previous release. All lld releases may be downloaded |
| from the `LLVM releases web site <https://llvm.org/releases/>`_. |
| |
| Non-comprehensive list of changes in this release |
| ================================================= |
| |
| ELF Improvements |
| ---------------- |
| |
| * Added ``--print-gc-sections=<file>`` to redirect garbage collection section |
| listing to a file, avoiding contamination of stdout with other linker output. |
| (`#159706 <https://github.com/llvm/llvm-project/pull/159706>`_) |
| * Added ``VersionNode`` lexer state for better version script parsing. |
| This brings the lexer behavior closer to GNU ld. |
| (`#174530 <https://github.com/llvm/llvm-project/pull/174530>`_) |
| * Unversioned undefined symbols now use version index 0, aligning with |
| GNU ld 2.46 behavior. |
| (`#168189 <https://github.com/llvm/llvm-project/pull/168189>`_) |
| * ``.data.rel.ro.hot`` and ``.data.rel.ro.unlikely`` are now recognized as |
| RELRO sections, allowing profile-guided static data partitioning. |
| (`#148920 <https://github.com/llvm/llvm-project/pull/148920>`_) |
| * DTLTO now supports archive members and bitcode members of thin archives. |
| (`#157043 <https://github.com/llvm/llvm-project/pull/157043>`_) |
| * For DTLTO, ``--thinlto-remote-compiler-prepend-arg=<arg>`` has been added to |
| prepend an argument to the remote compiler's command line. |
| (`#162456 <https://github.com/llvm/llvm-project/pull/162456>`_) |
| * Balanced Partitioning (BP) section ordering now skips input sections with |
| null data, and filters out section symbols. |
| (`#149265 <https://github.com/llvm/llvm-project/pull/149265>`_) |
| (`#151685 <https://github.com/llvm/llvm-project/pull/151685>`_) |
| * For AArch64, fixed a crash when using ``--fix-cortex-a53-843419`` with |
| synthetic sections and improved handling when patched code is far from |
| the short jump. |
| (`#170495 <https://github.com/llvm/llvm-project/pull/170495>`_) |
| * For AArch64, added support for the ``R_AARCH64_FUNCINIT64`` dynamic |
| relocation type for relocating word-sized data using the return value |
| of a function. |
| (`#156564 <https://github.com/llvm/llvm-project/pull/156564>`_) |
| * For AArch64, added support for the ``R_AARCH64_PATCHINST`` relocation type |
| to support deactivation symbols. |
| (`#133534 <https://github.com/llvm/llvm-project/pull/133534>`_) |
| * For AArch64, added support for reading AArch64 Build Attributes and |
| converting them into GNU Properties. |
| (`#147970 <https://github.com/llvm/llvm-project/pull/147970>`_) |
| * For ARM, fixed incorrect veneer generation for wraparound branches at |
| the high end of the 32-bit address space branching to the low end. |
| (`#165263 <https://github.com/llvm/llvm-project/pull/165263>`_) |
| * For LoongArch, ``-r`` now synthesizes ``R_LARCH_ALIGN`` at input section |
| start to preserve alignment information. |
| (`#153935 <https://github.com/llvm/llvm-project/pull/153935>`_) |
| * For LoongArch, added relocation types for LA32R/LA32S. |
| (`#172618 <https://github.com/llvm/llvm-project/pull/172618>`_) |
| (`#176312 <https://github.com/llvm/llvm-project/pull/176312>`_) |
| * For RISC-V, added infrastructure for handling vendor-specific relocations. |
| (`#159987 <https://github.com/llvm/llvm-project/pull/159987>`_) |
| * For RISC-V, added support for statically resolved vendor-specific relocations. |
| (`#169273 <https://github.com/llvm/llvm-project/pull/169273>`_) |
| * For RISC-V, ``-r`` now synthesizes ``R_RISCV_ALIGN`` at input section start |
| to preserve alignment information during two-stage linking. |
| (`#151639 <https://github.com/llvm/llvm-project/pull/151639>`_) |
| |
| Breaking changes |
| ---------------- |
| |
| COFF Improvements |
| ----------------- |
| |
| * Added ``-prefetch-inputs`` to improve link times by asynchronously loading input files in RAM. |
| This will dampen the effect of input file I/O latency on link times. |
| However this flag can have an adverse effect when linking a large number of inputs files, or if all |
| inputs do not fit in RAM at once. For those cases, linking might be a bit slower since the inputs |
| will be streamed into RAM upfront, only to be evicted later by swapping. |
| (`#169224 <https://github.com/llvm/llvm-project/pull/169224>`_) |
| * Added ``/sectionlayout:@<file>`` to specify custom output section ordering. |
| (`#152779 <https://github.com/llvm/llvm-project/pull/152779>`_) |
| * Added ``/nodbgdirmerge`` to emit the debug directory section in ``.cvinfo`` |
| instead of merging it to ``.rdata``. |
| (`#159235 <https://github.com/llvm/llvm-project/pull/159235>`_) |
| * Added ``-fat-lto-objects`` to support FatLTO. Without ``-fat-lto-objects`` or |
| with ``-fat-lto-objects:no``, LLD will link LLVM FatLTO objects using the |
| relocatable object file. |
| (`#165529 <https://github.com/llvm/llvm-project/pull/165529>`_) |
| * Added ``/linkreprofullpathrsp`` to print the full path to each object |
| passed to the link line to a file. This is used in particular when linking |
| Arm64X binaries. |
| (`#174971 <https://github.com/llvm/llvm-project/pull/174971>`_) |
| * Added CET flags: ``/cetcompatstrict``, ``/cetipvalidationrelaxed``, |
| ``/cetdynamicapisinproc``, and ``/hotpatchcompatible``. |
| (`#150761 <https://github.com/llvm/llvm-project/pull/150761>`_) |
| * Added support for ARM64X same-address thunks. |
| (`#151255 <https://github.com/llvm/llvm-project/pull/151255>`_) |
| * Added more ``--time-trace`` tags for ThinLTO linking. |
| (`#156471 <https://github.com/llvm/llvm-project/pull/156471>`_) |
| * ``/summary`` now works when ``/debug`` isn't provided. |
| (`#157476 <https://github.com/llvm/llvm-project/pull/157476>`_) |
| * ``/summary`` now displays the size of all consumed inputs. |
| (`#157284 <https://github.com/llvm/llvm-project/pull/157284>`_) |
| * For DTLTO, ``-thinlto-remote-compiler-prepend-arg:<arg>`` has been added to |
| prepend an argument to the remote compiler's command line. |
| (`#162456 <https://github.com/llvm/llvm-project/pull/162456>`_) |
| * Loop and SLP vectorize options are now passed to the LTO backend. |
| (`#173041 <https://github.com/llvm/llvm-project/pull/173041>`_) |
| * Deduplicate common chunks when linking COFF files. |
| (`#162553 <https://github.com/llvm/llvm-project/pull/162553>`_) |
| * Discard ``.llvmbc`` and ``.llvmcmd`` sections. |
| (`#150897 <https://github.com/llvm/llvm-project/pull/150897>`_) |
| * Prevent emitting relocations for discarded weak wrapped symbols. |
| (`#156214 <https://github.com/llvm/llvm-project/pull/156214>`_) |
| |
| MinGW Improvements |
| ------------------ |
| |
| * Added ``--fat-lto-objects`` flag. |
| (`#174962 <https://github.com/llvm/llvm-project/pull/174962>`_) |
| * Handle ``-m mipspe`` for MIPS. |
| (`#157742 <https://github.com/llvm/llvm-project/pull/157742>`_) |
| * Fixed implicit DLL entry point for MinGW. |
| (`#171680 <https://github.com/llvm/llvm-project/pull/171680>`_) |
| |
| MachO Improvements |
| ------------------ |
| |
| * Added ``--read-workers=<N>`` for multi-threaded preload of input files |
| into memory, significantly reducing link times for large projects. |
| (`#147134 <https://github.com/llvm/llvm-project/pull/147134>`_) |
| * Added ``--separate-cstring-literal-sections`` to emit cstring literals |
| into sections defined by their section name. |
| (`#158720 <https://github.com/llvm/llvm-project/pull/158720>`_) |
| * Added ``--tail-merge-strings`` to enable tail merging of cstrings. |
| (`#161262 <https://github.com/llvm/llvm-project/pull/161262>`_) |
| * Added ``--lto-emit-llvm`` command line option. |
| * Added ``--slop-scale`` flag for adjusting slop scale. |
| (`#164295 <https://github.com/llvm/llvm-project/pull/164295>`_) |
| * Added support for section branch relocations, including the 1-byte form. |
| (`#169062 <https://github.com/llvm/llvm-project/pull/169062>`_) |
| * Enabled Linker Optimization Hints pass for arm64_32. |
| (`#148964 <https://github.com/llvm/llvm-project/pull/148964>`_) |
| * Read cstring order for non-deduped sections. |
| (`#161879 <https://github.com/llvm/llvm-project/pull/161879>`_) |
| * Allow independent override of weak symbols aliased via ``.set``. |
| (`#167825 <https://github.com/llvm/llvm-project/pull/167825>`_) |
| * Fixed segfault while processing malformed object file. |
| (`#167025 <https://github.com/llvm/llvm-project/pull/167025>`_) |
| * Fixed infinite recursion when parsing corrupted export tries. |
| (`#152569 <https://github.com/llvm/llvm-project/pull/152569>`_) |
| * Error out gracefully when offset is outside literal section. |
| (`#164660 <https://github.com/llvm/llvm-project/pull/164660>`_) |
| * Process OSO prefix only textually in both input and output. |
| (`#152063 <https://github.com/llvm/llvm-project/pull/152063>`_) |
| |
| WebAssembly Improvements |
| ------------------------ |
| |
| * ``--stack-first`` is now the default. Use ``--no-stack-first`` for the |
| old behavior. |
| (`#166998 <https://github.com/llvm/llvm-project/pull/166998>`_) |
| * ``--import-memory`` can now take a single name (imports from default module). |
| (`#160409 <https://github.com/llvm/llvm-project/pull/160409>`_) |
| * ``-r`` now forces ``-Bstatic``. |
| (`#108264 <https://github.com/llvm/llvm-project/pull/108264>`_) |
| * LTO now uses PIC reloc model with dynamic imports. |
| (`#165342 <https://github.com/llvm/llvm-project/pull/165342>`_) |
| * Honor command line reloc model during LTO. |
| (`#164838 <https://github.com/llvm/llvm-project/pull/164838>`_) |
| * Fixed visibility of ``__stack_pointer`` global. |
| (`#161284 <https://github.com/llvm/llvm-project/pull/161284>`_) |
| * Fixed check for exporting mutable globals. |
| (`#160787 <https://github.com/llvm/llvm-project/pull/160787>`_) |
| * Fixed check for implicitly exported mutable globals. |
| (`#160966 <https://github.com/llvm/llvm-project/pull/160966>`_) |
| * Don't export deps for unused stub symbols. |
| (`#173422 <https://github.com/llvm/llvm-project/pull/173422>`_) |
| * Fixed SEGFAULT when importing wrapped symbol. |
| (`#169656 <https://github.com/llvm/llvm-project/pull/169656>`_) |
| * Error on unexpected relocation types in ``-pie``/``-shared`` data sections. |
| (`#162117 <https://github.com/llvm/llvm-project/pull/162117>`_) |
| |
| Fixes |
| ##### |
