llvmPackages: git -> 21.0.0, init 20.1.0-rc1

pkgs/development/compilers/llvm/20/compiler-rt/libc-free.patch

@@ -0,0 +1,68 @@
+From 5eaae2daff7722ee01eee239e131ee1f62643abe Mon Sep 17 00:00:00 2001
+From: Peter Waller <[email protected]>
+Date: Wed, 5 Feb 2025 19:46:15 +0000
+Subject: [PATCH] [compiler-rt][AArch64] Enable libc-free builtins Linux build
+
+Without this change, libc++abi.so.1.0 fails to link with:
+
+```
+error: undefined sybol: __aarch64_sme_accessible
+```
+
+This symbol is provided by baremetal libc's such as newlib.
+
+In order to compile a libc with compiler-rt, it is necessary first to
+build a compiler-rt with no dependency on libc to acquire the builtins.
+The intended linux test requires getauxval which is provided by libc.
+
+To that end, there are examples in the wild of building a compiler-rt
+without libc by specifying -DCOMPILER_RT_BAREMETAL_BUILD=ON.
+On Linux, this gives a builtins build with (almost) no libc dependencies.
+
+See for example:
+
+https://github.com/NixOS/nixpkgs/blob/d7fe3bcaca37e79d8b3cbde4dd69edeafbd35313/pkgs/development/compilers/llvm/common/compiler-rt/default.nix#L116-L118
+
+```
+  ] ++ lib.optionals (!haveLibc || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+```
+
+The above specifies that a !haveLibc build sets
+`-DCOMPILER_RT_BAREMETAL_BUILD`, which is done for example in a `pkgsLLVM` build.
+
+AIUI, acquiring such a builtins build of compiler-rt is necessary to build a
+pure LLVM toolchain, since builtins are required to build libc (and
+libcxx is required to build a full compiler-rt).
+
+The effect of falling back to unimplemented is that this early-stage
+builtins build is incapable of doing function multiversioning tests and
+falls back to behaving as-if the feature is unavailable.
+
+This behaviour changed in
+https://github.com/llvm/llvm-project/pull/119414, which introduced a
+subtle change in semantics in the removal of
+compiler-rt/lib/builtins/aarch64/sme-abi-init.c (definition of getauxval
+macro, which was bracketed by `#if defined(__linux__)`) vs the new
+definition which does not test for linux.
+
+The proposed change is reinstating things as they were before #119414.
+---
+ compiler-rt/lib/builtins/cpu_model/aarch64.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/builtins/cpu_model/aarch64.c b/lib/builtins/cpu_model/aarch64.c
+index 4082fd62ea11a25..50438bcc7ddd885 100644
+--- a/lib/builtins/cpu_model/aarch64.c
++++ b/lib/builtins/cpu_model/aarch64.c
+@@ -80,7 +80,7 @@ struct {
+ #include "aarch64/fmv/getauxval.inc"
+ #elif defined(_WIN32)
+ #include "aarch64/fmv/windows.inc"
+-#elif defined(ENABLE_BAREMETAL_AARCH64_FMV)
++#elif defined(ENABLE_BAREMETAL_AARCH64_FMV) && !defined(__linux__)
+ #include "aarch64/fmv/baremetal.inc"
+ #else
+ #include "aarch64/fmv/unimplemented.inc"
+

pkgs/development/compilers/llvm/20/llvm/gnu-install-dirs.patch

@@ -0,0 +1,139 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index c9ff3696e22d..bd96aab5e237 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -1133,9 +1133,9 @@ if (NOT TENSORFLOW_AOT_PATH STREQUAL "")
+   add_subdirectory(${TENSORFLOW_AOT_PATH}/xla_aot_runtime_src
+     ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/tf_runtime)
+   install(TARGETS tf_xla_runtime EXPORT LLVMExports
+-    ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT tf_xla_runtime)
++    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT tf_xla_runtime)
+   install(TARGETS tf_xla_runtime EXPORT LLVMDevelopmentExports
+-    ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT tf_xla_runtime)
++    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT tf_xla_runtime)
+   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS tf_xla_runtime)
+   # Once we add more modules, we should handle this more automatically.
+   if (DEFINED LLVM_OVERRIDE_MODEL_HEADER_INLINERSIZEMODEL)
+diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
+index baf47677b247..81954240a9bf 100644
+--- a/cmake/modules/AddLLVM.cmake
++++ b/cmake/modules/AddLLVM.cmake
+@@ -974,8 +974,8 @@ macro(add_llvm_library name)
+       endif()
+       install(TARGETS ${name}
+               ${export_to_llvmexports}
+-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
++              LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
++              ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+               RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT ${name})
+
+       if (NOT LLVM_ENABLE_IDE)
+@@ -2243,7 +2243,7 @@ function(llvm_install_library_symlink name dest type)
+     set(LLVM_LINK_OR_COPY copy)
+   endif()
+
+-  set(output_dir lib${LLVM_LIBDIR_SUFFIX})
++  set(output_dir ${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   if(WIN32 AND "${type}" STREQUAL "SHARED")
+     set(output_dir "${CMAKE_INSTALL_BINDIR}")
+   endif()
+@@ -2519,16 +2519,37 @@ function(llvm_setup_rpath name)
+
+   if (APPLE)
+     set(_install_name_dir INSTALL_NAME_DIR "@rpath")
+-    set(_install_rpath "@loader_path/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
++    set(_install_rpath ${extra_libdir})
+   elseif(${CMAKE_SYSTEM_NAME} MATCHES "AIX" AND BUILD_SHARED_LIBS)
+     # $ORIGIN is not interpreted at link time by aix ld.
+     # Since BUILD_SHARED_LIBS is only recommended for use by developers,
+     # hardcode the rpath to build/install lib dir first in this mode.
+     # FIXME: update this when there is better solution.
+-    set(_install_rpath "${LLVM_LIBRARY_OUTPUT_INTDIR}" "${CMAKE_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
++    set(_install_rpath "${LLVM_LIBRARY_OUTPUT_INTDIR}" "${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+   elseif(UNIX)
++    # Note that we add `extra_libdir` (aka `LLVM_LIBRARY_DIR` in our case) back
++    # to `_install_rpath` here.
++    #
++    # In nixpkgs we do not build and install LLVM alongside rdeps of LLVM (i.e.
++    # clang); instead LLVM is its own package and thus lands at its own nix
++    # store path. This makes it so that the default relative rpath (`../lib/`)
++    # does not point at the LLVM shared objects.
++    #
++    # More discussion here:
++    #   - https://github.com/NixOS/nixpkgs/pull/235624#discussion_r1220150329
++    #   - https://reviews.llvm.org/D146918 (16.0.5+)
++    #
++    # Note that we leave `extra_libdir` in `_build_rpath`: without FHS there is
++    # no potential that this will result in us pulling in the "wrong" LLVM.
++    # Adding this to the build rpath means we aren't forced to use
++    # `installCheckPhase` instead of `checkPhase` (i.e. binaries in the build
++    # dir, pre-install, will have the right rpath for LLVM).
++    #
++    # As noted in the differential above, an alternative solution is to have
++    # all rdeps of nixpkgs' LLVM (that use the AddLLVM.cmake machinery) set
++    # `CMAKE_INSTALL_RPATH`.
+     set(_build_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}")
++    set(_install_rpath ${extra_libdir})
+     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
+       set_property(TARGET ${name} APPEND_STRING PROPERTY
+                    LINK_FLAGS " -Wl,-z,origin ")
+diff --git a/cmake/modules/AddOCaml.cmake b/cmake/modules/AddOCaml.cmake
+index 2d9116b08a52..2dd7cad4ec66 100644
+--- a/cmake/modules/AddOCaml.cmake
++++ b/cmake/modules/AddOCaml.cmake
+@@ -147,9 +147,9 @@ function(add_ocaml_library name)
+   endforeach()
+
+   if( APPLE )
+-    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
++    set(ocaml_rpath ${LLVM_LIBRARY_DIR})
+   elseif( UNIX )
+-    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
++    set(ocaml_rpath ${LLVM_LIBRARY_DIR})
+   endif()
+   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
+
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index ef4cfa3acdb5..7478e157a7c2 100644
+--- a/cmake/modules/CMakeLists.txt
++++ b/cmake/modules/CMakeLists.txt
+@@ -130,7 +130,7 @@ set(LLVM_CONFIG_INCLUDE_DIRS
+   )
+ list(REMOVE_DUPLICATES LLVM_CONFIG_INCLUDE_DIRS)
+
+-extend_path(LLVM_CONFIG_LIBRARY_DIR "\${LLVM_INSTALL_PREFIX}" "lib\${LLVM_LIBDIR_SUFFIX}")
++extend_path(LLVM_CONFIG_LIBRARY_DIR "\${LLVM_INSTALL_PREFIX}" "${CMAKE_INSTALL_LIBDIR}\${LLVM_LIBDIR_SUFFIX}")
+ set(LLVM_CONFIG_LIBRARY_DIRS
+   "${LLVM_CONFIG_LIBRARY_DIR}"
+   # FIXME: Should there be other entries here?
+diff --git a/tools/llvm-config/BuildVariables.inc.in b/tools/llvm-config/BuildVariables.inc.in
+index 370005cd8d7d..7e790bc52111 100644
+--- a/tools/llvm-config/BuildVariables.inc.in
++++ b/tools/llvm-config/BuildVariables.inc.in
+@@ -23,6 +23,7 @@
+ #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
+ #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
+ #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
++#define LLVM_INSTALL_LIBDIR "@CMAKE_INSTALL_LIBDIR@"
+ #define LLVM_INSTALL_INCLUDEDIR "@CMAKE_INSTALL_INCLUDEDIR@"
+ #define LLVM_INSTALL_PACKAGE_DIR "@LLVM_INSTALL_PACKAGE_DIR@"
+ #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
+diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
+index d5b76b1bb6c1..1dbdb2a8f10d 100644
+--- a/tools/llvm-config/llvm-config.cpp
++++ b/tools/llvm-config/llvm-config.cpp
+@@ -366,7 +366,11 @@ int main(int argc, char **argv) {
+       sys::fs::make_absolute(ActivePrefix, Path);
+       ActiveBinDir = std::string(Path);
+     }
+-    ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
++    {
++      SmallString<256> Path(LLVM_INSTALL_LIBDIR LLVM_LIBDIR_SUFFIX);
++      sys::fs::make_absolute(ActivePrefix, Path);
++      ActiveLibDir = std::string(Path);
++    }
+     {
+       SmallString<256> Path(LLVM_INSTALL_PACKAGE_DIR);
+       sys::fs::make_absolute(ActivePrefix, Path);

pkgs/development/compilers/llvm/20/llvm/orcjit.patch

@@ -0,0 +1,53 @@
+From 03d6f704d07aa3650a2f59be6f7802a8735460c3 Mon Sep 17 00:00:00 2001
+From: Lang Hames <[email protected]>
+Date: Wed, 29 Jan 2025 03:58:29 +0000
+Subject: [PATCH] [ORC][LLI] Remove redundant eh-frame registration plugin
+ construction from lli.
+
+As of d0052ebbe2e the setUpGenericLLVMIRPlatform function will automatically
+add an instance of the EHFrameRegistrationPlugin (for LLJIT instances whose
+object linking layers are ObjectLinkingLayers, not RTDyldObjectLinkingLayers).
+
+This commit removes the redundant plugin creation in the object linking
+layer constructor function in lli.cpp to prevent duplicate registration of
+eh-frames, which is likely the cause of recent bot failures, e.g.
+https://lab.llvm.org/buildbot/#/builders/108/builds/8685.
+
+(cherry picked from commit 9052b37ab1aa67a039b34356f37236fecc42bac2)
+---
+ llvm/tools/lli/lli.cpp | 14 ++++----------
+ 1 file changed, 4 insertions(+), 10 deletions(-)
+
+diff --git a/llvm/tools/lli/lli.cpp b/tools/lli/lli.cpp
+index 448660a539a0b0..19246f03941673 100644
+--- a/llvm/tools/lli/lli.cpp
++++ b/tools/lli/lli.cpp
+@@ -27,9 +27,7 @@
+ #include "llvm/ExecutionEngine/Orc/AbsoluteSymbols.h"
+ #include "llvm/ExecutionEngine/Orc/DebugUtils.h"
+ #include "llvm/ExecutionEngine/Orc/Debugging/DebuggerSupport.h"
+-#include "llvm/ExecutionEngine/Orc/EHFrameRegistrationPlugin.h"
+ #include "llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h"
+-#include "llvm/ExecutionEngine/Orc/EPCEHFrameRegistrar.h"
+ #include "llvm/ExecutionEngine/Orc/EPCGenericRTDyldMemoryManager.h"
+ #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
+ #include "llvm/ExecutionEngine/Orc/IRPartitionLayer.h"
+@@ -1033,14 +1031,10 @@ int runOrcJIT(const char *ProgName) {
+     Builder.getJITTargetMachineBuilder()
+         ->setRelocationModel(Reloc::PIC_)
+         .setCodeModel(CodeModel::Small);
+-    Builder.setObjectLinkingLayerCreator([&P](orc::ExecutionSession &ES,
+-                                              const Triple &TT) {
+-      auto L = std::make_unique<orc::ObjectLinkingLayer>(ES);
+-      if (P != LLJITPlatform::ExecutorNative)
+-        L->addPlugin(std::make_unique<orc::EHFrameRegistrationPlugin>(
+-            ES, ExitOnErr(orc::EPCEHFrameRegistrar::Create(ES))));
+-      return L;
+-    });
++    Builder.setObjectLinkingLayerCreator(
++        [&](orc::ExecutionSession &ES, const Triple &TT) {
++          return std::make_unique<orc::ObjectLinkingLayer>(ES);
++        });
+   }
+
+   auto J = ExitOnErr(Builder.create());

pkgs/development/compilers/llvm/common/default.nix

@@ -123,8 +123,13 @@ let
                 }
               ];
               "llvm/gnu-install-dirs.patch" = [
+                {
+                  after = "20";
+                  path = ../20;
+                }
                 {
                   after = "18";
+                  before = "20";
                   path = ../18;
                 }
               ];
@@ -494,7 +499,12 @@ let
                   hash = "sha256-EX+PYGicK73lsL/J0kSZ4S5y1/NHIclBddhsnV6NPPI=";
                   stripLen = 1;
                 })
-              ];
+              ]
+          ++
+            lib.optional (lib.versions.major metadata.release_version == "20")
+              # Fix OrcJIT
+              # PR: https://github.com/llvm/llvm-project/pull/125431
+              (metadata.getVersionFile "llvm/orcjit.patch");
         pollyPatches =
           [ (metadata.getVersionFile "llvm/gnu-install-dirs-polly.patch") ]
           ++ lib.optional (lib.versionAtLeast metadata.release_version "15")
@@ -1076,7 +1086,12 @@ let
           url = "https://github.com/llvm/llvm-project/pull/99837/commits/14ae0a660a38e1feb151928a14f35ff0f4487351.patch";
           hash = "sha256-JykABCaNNhYhZQxCvKiBn54DZ5ZguksgCHnpdwWF2no=";
           relative = "compiler-rt";
-        });
+        })
+        # Fixes baremetal
+        # PR: https://github.com/llvm/llvm-project/pull/125922
+        ++ lib.optional (lib.versionAtLeast metadata.release_version "20") (
+          metadata.getVersionFile "compiler-rt/libc-free.patch"
+        );
     in
     (
       {

pkgs/development/compilers/llvm/common/libc/default.nix

@@ -31,7 +31,7 @@ let
       stdenv.override {
         cc = stdenv.cc.override {
           nixSupport = stdenv.cc.nixSupport // {
-            cc-cflags = lib.remove "-lunwind" stdenv.cc.nixSupport.cc-cflags;
+            cc-cflags = lib.remove "-lunwind" (stdenv.cc.nixSupport.cc-cflags or [ ]);
           };
         };
       }
@@ -58,8 +58,8 @@ stdenv'.mkDerivation (finalAttrs: {
   outputs = [ "out" ] ++ (lib.optional isFullBuild "dev");
 
   postUnpack = lib.optionalString isFullBuild ''
-    patchShebangs $sourceRoot/../$pname/hdrgen/yaml_to_classes.py
-    chmod +x $sourceRoot/../$pname/hdrgen/yaml_to_classes.py
+    patchShebangs $sourceRoot/../$pname/utils/hdrgen/main.py
+    chmod +x $sourceRoot/../$pname/utils/hdrgen/main.py
   '';
 
   prePatch = ''

pkgs/development/compilers/llvm/default.nix

@@ -30,10 +30,11 @@ let
     "17.0.6".officialRelease.sha256 = "sha256-8MEDLLhocshmxoEBRSKlJ/GzJ8nfuzQ8qn0X/vLA+ag=";
     "18.1.8".officialRelease.sha256 = "sha256-iiZKMRo/WxJaBXct9GdAcAT3cz9d9pnAcO1mmR6oPNE=";
     "19.1.6".officialRelease.sha256 = "sha256-LD4nIjZTSZJtbgW6tZopbTF5Mq0Tenj2gbuPXhtOeUI=";
-    "20.0.0-git".gitRelease = {
-      rev = "6383a12e3b4339fa4743bb97da4d51dea6d2e2ea";
-      rev-version = "20.0.0-unstable-2025-01-25";
-      sha256 = "sha256-LMew+lFm+HrR5iwFDnoXA6B2LiU/pVqsy1YrP9xr5GU=";
+    "20.1.0-rc1".officialRelease.sha256 = "sha256-yOczbperlR20+iLoao9g0CR+Ml2mjTCx1cqP/9WOhME=";
+    "21.0.0-git".gitRelease = {
+      rev = "312055d1da169f043e65b35fcd62d6d685700114";
+      rev-version = "21.0.0-unstable-2025-02-01";
+      sha256 = "sha256-V14ypUGn7GxzchmKjoSH2oiHDUQa07b4bQWjjRpQKCo=";
     };
   } // llvmVersions;
 

pkgs/top-level/aliases.nix

@@ -1595,7 +1595,7 @@ mapAliases {
   openbsdCross = openbsd; # Added 2024-09-06
 
   # LLVM packages for (integration) testing that should not be used inside Nixpkgs:
-  llvmPackages_latest = llvmPackages_19;
+  llvmPackages_latest = llvmPackages_20;
 
   /* If these are in the scope of all-packages.nix, they cause collisions
     between mixed versions of qt. See:

pkgs/top-level/all-packages.nix

@@ -6434,6 +6434,13 @@ with pkgs;
     lldb_19 = llvmPackages_19.lldb;
     llvm_19 = llvmPackages_19.llvm;
     bolt_19 = llvmPackages_19.bolt;
+
+    llvmPackages_20 = llvmPackagesSet."20";
+    clang_20 = llvmPackages_20.clang;
+    lld_20 = llvmPackages_20.lld;
+    lldb_20 = llvmPackages_20.lldb;
+    llvm_20 = llvmPackages_20.llvm;
+    bolt_20 = llvmPackages_20.bolt;
   }) llvmPackages_12
     llvmPackages_13
     llvmPackages_14
@@ -6450,7 +6457,13 @@ with pkgs;
     lld_19
     lldb_19
     llvm_19
-    bolt_19;
+    bolt_19
+    llvmPackages_20
+    clang_20
+    lld_20
+    lldb_20
+    llvm_20
+    bolt_20;
 
   lorri = callPackage ../tools/misc/lorri {
     inherit (darwin.apple_sdk.frameworks) CoreServices Security;
@@ -8983,8 +8996,7 @@ with pkgs;
     else if name == "wasilibc" then targetPackages.wasilibc or wasilibc
     else if name == "relibc" then targetPackages.relibc or relibc
     else if name == "llvm" then
-      # Use llvmPackages_git until LLVM 20 is the default.
-      targetPackages.llvmPackages_git.libc or llvmPackages_git.libc
+      targetPackages.llvmPackages_20.libc or llvmPackages_20.libc
     else throw "Unknown libc ${name}";
 
   libcCross =