PR for llvm/llvm-project#56840

clang/lib/Driver/ToolChains/Gnu.cpp

@@ -631,6 +631,16 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
 
+      // LLVM support for atomics on 32-bit SPARC V8+ is incomplete, so
+      // forcibly link with libatomic as a workaround.
+      // TODO: Issue #41880 and D118021.
+      if (getToolChain().getTriple().getArch() == llvm::Triple::sparc) {
+        CmdArgs.push_back("--push-state");
+        CmdArgs.push_back("--as-needed");
+        CmdArgs.push_back("-latomic");
+        CmdArgs.push_back("--pop-state");
+      }
+
       if (WantPthread && !isAndroid)
         CmdArgs.push_back("-lpthread");
 

clang/test/Driver/linux-ld.c

@@ -1007,6 +1007,7 @@
 // CHECK-SPARCV8: "{{.*}}ld{{(.exe)?}}"
 // CHECK-SPARCV8: "-m" "elf32_sparc"
 // CHECK-SPARCV8: "-dynamic-linker" "{{(/usr/sparc-unknown-linux-gnu)?}}/lib/ld-linux.so.2"
+// CHECK-SPARCV8: "--push-state" "--as-needed" "-latomic" "--pop-state"
 //
 // RUN: %clang -### %s -no-pie 2>&1 \
 // RUN:     --target=sparcel-unknown-linux-gnu \
@@ -1021,6 +1022,7 @@
 // CHECK-SPARCV9: "{{.*}}ld{{(.exe)?}}"
 // CHECK-SPARCV9: "-m" "elf64_sparc"
 // CHECK-SPARCV9: "-dynamic-linker" "{{(/usr/sparcv9-unknown-linux-gnu)?}}/lib{{(64)?}}/ld-linux.so.2"
+// CHECK-SPARCV9-NOT: "-latomic"
 
 // Test linker invocation on Android.
 // RUN: %clang -### %s -no-pie 2>&1 \

lld/docs/ReleaseNotes.rst

@@ -71,6 +71,117 @@ MachO Improvements
   (`D129540 <https://reviews.llvm.org/D129540>`_,
   `D122258 <https://reviews.llvm.org/D122258>`_)
 
+New flags
+#########
+
+* ``-load_hidden`` and ``-hidden-l`` are now supported.
+  (`D130473 <https://reviews.llvm.org/D130473>`_,
+  `D130529 <https://reviews.llvm.org/D130529>`_)
+* ``-alias`` is now supported. (`D129938 <https://reviews.llvm.org/D129938>`_)
+* ``-no_exported_symbols`` and  ``-exported_symbols_list <empty file>`` are now
+  supported. (`D127562 <https://reviews.llvm.org/D127562>`_)
+* ``-w`` -- to suppress warnings -- is now supported.
+  (`D127564 <https://reviews.llvm.org/D127564>`_)
+* ``-non_global_symbols_strip_list``, ``-non_global_symbols_no_strip_list``, and
+  ``-x`` are now supported. (`D126046 <https://reviews.llvm.org/D126046>`_)
+* ``--icf=safe`` is now supported.
+  (`D128938 <https://reviews.llvm.org/D128938>`_,
+  `D123752 <https://reviews.llvm.org/D123752>`_)
+* ``-why_live`` is now supported.
+  (`D120377 <https://reviews.llvm.org/D120377>`_)
+* ``-pagezero_size`` is now supported.
+  (`D118724 <https://reviews.llvm.org/D118724>`_)
+
+Improvements
+############
+
+* Linker optimization hints are now supported.
+  (`D129427 <https://reviews.llvm.org/D129427>`_,
+  `D129059 <https://reviews.llvm.org/D129059>`_,
+  `D128942 <https://reviews.llvm.org/D128942>`_,
+  `D128093 <https://reviews.llvm.org/D128093>`_)
+* Rebase opcodes are now encoded more compactly.
+  (`D130180 <https://reviews.llvm.org/D130180>`_,
+  `D128798 <https://reviews.llvm.org/D128798>`_)
+* C-strings are now aligned more compactly.
+  (`D121342 <https://reviews.llvm.org/D121342>`_)
+* ``--deduplicate-literals`` (and ``--icf={safe,all}``) now fold the
+  ``__cfstring`` section.
+  (`D130134  <https://reviews.llvm.org/D130134>`_,
+  `D120137 <https://reviews.llvm.org/D120137>`_)
+* ICF now folds the ``__objc_classrefs`` section.
+  (`D121053 <https://reviews.llvm.org/D121053>`_)
+* ICF now folds functions with identical LSDAs.
+  (`D129830 <https://reviews.llvm.org/D129830>`_)
+* STABS entries for folded functions are now omitted.
+  (`D123252 <https://reviews.llvm.org/D123252>`_)
+* ``__objc_imageinfo`` sections are now folded.
+  (`D130125 <https://reviews.llvm.org/D130125>`_)
+* Dylibs with ``LC_DYLD_EXPORTS_TRIE`` can now be read.
+  (`D129430 <https://reviews.llvm.org/D129430>`_)
+* Writing zippered dylibs is now supported.
+  (`D124887 <https://reviews.llvm.org/D124887>`_)
+* C-string literals are now included in the mapfile.
+  (`D118077 <https://reviews.llvm.org/D118077>`_)
+* Symbol names in several more diagnostics are now demangled.
+  (`D130490 <https://reviews.llvm.org/D130490>`_,
+  `D127110 <https://reviews.llvm.org/D127110>`_,
+  `D125732 <https://reviews.llvm.org/D125732>`_)
+* Source information is now included in symbol error messages.
+  (`D128425 <https://reviews.llvm.org/D128425>`_,
+  `D128184 <https://reviews.llvm.org/D128184>`_)
+* Numerous other improvements were made to diagnostic messages.
+  (`D127753 <https://reviews.llvm.org/D127753>`_,
+  `D127696 <https://reviews.llvm.org/D127696>`_,
+  `D127670 <https://reviews.llvm.org/D127670>`_,
+  `D118903 <https://reviews.llvm.org/D118903>`_,
+  `D118798 <https://reviews.llvm.org/D118798>`_)
+* Many performance and memory improvements were made.
+  (`D130000 <https://reviews.llvm.org/D130000>`_,
+  `D128298 <https://reviews.llvm.org/D128298>`_,
+  `D128290 <https://reviews.llvm.org/D128290>`_,
+  `D126800 <https://reviews.llvm.org/D126800>`_,
+  `D126785 <https://reviews.llvm.org/D126785>`_,
+  `D121052 <https://reviews.llvm.org/D121052>`_)
+* Order files and call graph sorting can now be used together.
+  (`D117354 <https://reviews.llvm.org/D117354>`_)
+* Give LTO more precise symbol resolutions, which allows optimizations to be
+  more effective.
+  (`D119506 <https://reviews.llvm.org/D119506>`_,
+  `D119372 <https://reviews.llvm.org/D119372>`_,
+  `D119767 <https://reviews.llvm.org/D119767>`_)
+* Added partial support for linking object files built with DTrace probes.
+  (`D129062 <https://reviews.llvm.org/D129062>`_)
+
+Fixes
+#####
+
+* Programs using Swift linked with the 14.0 SDK but an older deployment target
+  no longer crash at startup when running on older iOS versions. This is because
+  we now correctly support ``$ld$previous`` symbols that contain an explicit
+  symbol name. (`D130725 <https://reviews.llvm.org/D130725>`_)
+* Match ld64's behavior when an archive is specified both via
+  ``LC_LINKER_OPTION`` and via the command line.
+  (`D129556 <https://reviews.llvm.org/D129556>`_)
+* ``-ObjC`` now correctly loads archives with Swift sections.
+  (`D125250 <https://reviews.llvm.org/D125250>`_)
+* ``-lto_object_path`` now accepts a filename (instead of just a directory
+  name.) (`D129705 <https://reviews.llvm.org/D129705>`_)
+* The ``LC_UUID`` hash now includes the output file's name.
+  (`D122843 <https://reviews.llvm.org/D122843>`_)
+* ``-flat_namespace`` now correctly makes all extern symbols in a dylib
+  interposable. (`D119294 <https://reviews.llvm.org/D119294>`_)
+* Fixed compact unwind output when linking on 32-bit hosts.
+  (`D129363 <https://reviews.llvm.org/D129363>`_)
+* Exporting private symbols no longer triggers an assertion.
+  (`D124143 <https://reviews.llvm.org/D124143>`_)
+* MacOS-only ``.tbd`` files are now supported when targeting Catalyst.
+  (`D124336 <https://reviews.llvm.org/D124336>`_)
+* Thunk symbols now have local visibility, avoiding false duplicate symbol
+  errors. (`D122624 <https://reviews.llvm.org/D122624>`_)
+* Fixed handling of relocatable object files within frameworks.
+  (`D114841 <https://reviews.llvm.org/D114841>`_)
+
 WebAssembly Improvements
 ------------------------