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-rw-r--r--pkgs/development/compilers/llvm/12/default.nix47
-rw-r--r--pkgs/development/compilers/llvm/12/llvm/default.nix357
-rw-r--r--pkgs/development/compilers/llvm/13/default.nix42
-rw-r--r--pkgs/development/compilers/llvm/13/llvm/default.nix315
-rw-r--r--pkgs/development/compilers/llvm/14/default.nix23
-rw-r--r--pkgs/development/compilers/llvm/14/llvm/default.nix323
-rw-r--r--pkgs/development/compilers/llvm/15/default.nix59
-rw-r--r--pkgs/development/compilers/llvm/15/llvm/default.nix442
-rw-r--r--pkgs/development/compilers/llvm/16/default.nix52
-rw-r--r--pkgs/development/compilers/llvm/16/llvm/default.nix435
-rw-r--r--pkgs/development/compilers/llvm/17/default.nix52
-rw-r--r--pkgs/development/compilers/llvm/17/llvm/default.nix431
-rw-r--r--pkgs/development/compilers/llvm/18/default.nix52
-rw-r--r--pkgs/development/compilers/llvm/common/clang/default.nix6
-rw-r--r--pkgs/development/compilers/llvm/common/llvm/default.nix (renamed from pkgs/development/compilers/llvm/18/llvm/default.nix)334
-rw-r--r--pkgs/development/compilers/llvm/git/default.nix52
-rw-r--r--pkgs/development/compilers/llvm/git/llvm/default.nix435
17 files changed, 585 insertions, 2872 deletions
diff --git a/pkgs/development/compilers/llvm/12/default.nix b/pkgs/development/compilers/llvm/12/default.nix
index 45955dc5e1b36..82a9d63ab3300 100644
--- a/pkgs/development/compilers/llvm/12/default.nix
+++ b/pkgs/development/compilers/llvm/12/default.nix
@@ -58,7 +58,52 @@ let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      src = fetch "llvm" "1pzx9zrmd7r3481sbhwvkms68fwhffpp4mmz45dgrkjpyl2q96kx";
+      polly_src = fetch "polly" "1yfm9ixda4a2sx7ak5vswijx4ydk5lv1c1xh39xmd2kh299y4m12";
+      patches = [
+        # When cross-compiling we configure llvm-config-native with an approximation
+        # of the flags used for the normal LLVM build. To avoid the need for building
+        # a native libLLVM.so (which would fail) we force llvm-config to be linked
+        # statically against the necessary LLVM components always.
+        ../common/llvm/llvm-config-link-static.patch
+        # Fix llvm being miscompiled by some gccs. See llvm/llvm-project#49955
+        # Fix llvm being miscompiled by some gccs. See https://github.com/llvm/llvm-project/issues/49955
+        ./llvm/fix-llvm-issue-49955.patch
+
+        ./llvm/gnu-install-dirs.patch
+        # On older CPUs (e.g. Hydra/wendy) we'd be getting an error in this test.
+        (fetchpatch {
+          name = "uops-CMOV16rm-noreg.diff";
+          url = "https://github.com/llvm/llvm-project/commit/9e9f991ac033.diff";
+          sha256 = "sha256:12s8vr6ibri8b48h2z38f3afhwam10arfiqfy4yg37bmc054p5hi";
+          stripLen = 1;
+        })
+
+        # Fix musl build.
+        (fetchpatch {
+          url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+          relative = "llvm";
+          hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+        })
+
+        # Backport gcc-13 fixes with missing includes.
+        (fetchpatch {
+          name = "signals-gcc-13.patch";
+          url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
+          hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
+          stripLen = 1;
+        })
+        (fetchpatch {
+          name = "base64-gcc-13.patch";
+          url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
+          hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
+          stripLen = 1;
+        })
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/12/llvm/default.nix b/pkgs/development/compilers/llvm/12/llvm/default.nix
deleted file mode 100644
index 4745345a3f712..0000000000000
--- a/pkgs/development/compilers/llvm/12/llvm/default.nix
+++ /dev/null
@@ -1,357 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, fetch
-, fetchpatch
-, cmake
-, python3
-, libffi
-, enableGoldPlugin ? libbfd.hasPluginAPI
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? stdenv.isLinux && (!stdenv.isx86_32) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-# broken for the armv7l builder
-, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
-, enablePolly ? false
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in python3.withPackages checkDeps
-  else python3;
-
-in stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = fetch pname "1pzx9zrmd7r3481sbhwvkms68fwhffpp4mmz45dgrkjpyl2q96kx";
-  polly_src = fetch "polly" "1yfm9ixda4a2sx7ak5vswijx4ydk5lv1c1xh39xmd2kh299y4m12";
-
-  unpackPhase = ''
-    unpackFile $src
-    mv llvm-${release_version}* llvm
-    sourceRoot=$PWD/llvm
-  '' + optionalString enablePolly ''
-    unpackFile $polly_src
-    mv polly-* $sourceRoot/tools/polly
-  '';
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake python ]
-    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = optionals (stdenv.buildPlatform == stdenv.hostPlatform) [ ncurses ]
-    ++ [ zlib ];
-
-  patches = [
-    # When cross-compiling we configure llvm-config-native with an approximation
-    # of the flags used for the normal LLVM build. To avoid the need for building
-    # a native libLLVM.so (which would fail) we force llvm-config to be linked
-    # statically against the necessary LLVM components always.
-    ../../common/llvm/llvm-config-link-static.patch
-    # Fix llvm being miscompiled by some gccs. See llvm/llvm-project#49955
-    # Fix llvm being miscompiled by some gccs. See https://github.com/llvm/llvm-project/issues/49955
-    ./fix-llvm-issue-49955.patch
-
-    ./gnu-install-dirs.patch
-    # On older CPUs (e.g. Hydra/wendy) we'd be getting an error in this test.
-    (fetchpatch {
-      name = "uops-CMOV16rm-noreg.diff";
-      url = "https://github.com/llvm/llvm-project/commit/9e9f991ac033.diff";
-      sha256 = "sha256:12s8vr6ibri8b48h2z38f3afhwam10arfiqfy4yg37bmc054p5hi";
-      stripLen = 1;
-    })
-
-    # Fix musl build.
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
-      relative = "llvm";
-      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
-    })
-
-    # Backport gcc-13 fixes with missing includes.
-    (fetchpatch {
-      name = "signals-gcc-13.patch";
-      url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
-      hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
-      stripLen = 1;
-    })
-    (fetchpatch {
-      name = "base64-gcc-13.patch";
-      url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
-      hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
-      stripLen = 1;
-    })
-  ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    # TODO: Fix failing tests:
-    rm test/DebugInfo/X86/vla-multi.ll
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-objcopy/MachO/universal-object.test
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '' + ''
-    # Tweak tests to ignore namespace part of type to support
-    # gcc-12: https://gcc.gnu.org/PR103598.
-    # The change below mangles strings like:
-    #    CHECK-NEXT: Starting llvm::Function pass manager run.
-    # to:
-    #    CHECK-NEXT: Starting {{.*}}Function pass manager run.
-    for f in \
-      test/Other/new-pass-manager.ll \
-      test/Other/new-pm-O0-defaults.ll \
-      test/Other/new-pm-defaults.ll \
-      test/Other/new-pm-lto-defaults.ll \
-      test/Other/new-pm-thinlto-defaults.ll \
-      test/Other/pass-pipeline-parsing.ll \
-      test/Transforms/Inline/cgscc-incremental-invalidate.ll \
-      test/Transforms/Inline/clear-analyses.ll \
-      test/Transforms/LoopUnroll/unroll-loop-invalidation.ll \
-      test/Transforms/SCCP/ipsccp-preserve-analysis.ll \
-      test/Transforms/SCCP/preserve-analysis.ll \
-      test/Transforms/SROA/dead-inst.ll \
-      test/tools/gold/X86/new-pm.ll \
-      ; do
-      echo "PATCH: $f"
-      substituteInPlace $f \
-        --replace 'Starting llvm::' 'Starting {{.*}}' \
-        --replace 'Finished llvm::' 'Finished {{.*}}'
-    done
-  '' + ''
-    # gcc-13 fix
-    sed -i '/#include <string>/i#include <cstdint>' \
-      include/llvm/DebugInfo/Symbolize/DIPrinter.h
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
-    )
-  '';
-
-  # hacky fix: created binaries need to be run before installation
-  preBuild = ''
-    mkdir -p $out/
-    ln -sv $PWD/lib $out
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  hardeningDisable = [ "trivialautovarinit" ];
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals (enableGoldPlugin) [
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postBuild = ''
-    rm -fR $out
-  '';
-
-  preCheck = ''
-    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
-  '';
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  buildPhase = ''
-    make docs-llvm-man
-  '';
-
-  propagatedBuildInputs = [];
-
-  installPhase = ''
-    make -C docs install
-  '';
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})
diff --git a/pkgs/development/compilers/llvm/13/default.nix b/pkgs/development/compilers/llvm/13/default.nix
index 018fb0c638505..9348e19e6de39 100644
--- a/pkgs/development/compilers/llvm/13/default.nix
+++ b/pkgs/development/compilers/llvm/13/default.nix
@@ -84,7 +84,47 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        # When cross-compiling we configure llvm-config-native with an approximation
+        # of the flags used for the normal LLVM build. To avoid the need for building
+        # a native libLLVM.so (which would fail) we force llvm-config to be linked
+        # statically against the necessary LLVM components always.
+        ../common/llvm/llvm-config-link-static.patch
+
+        ./llvm/gnu-install-dirs.patch
+
+        # Fix random compiler crashes: https://bugs.llvm.org/show_bug.cgi?id=50611
+        (fetchpatch {
+          url = "https://raw.githubusercontent.com/archlinux/svntogit-packages/4764a4f8c920912a2bfd8b0eea57273acfe0d8a8/trunk/no-strict-aliasing-DwarfCompileUnit.patch";
+          sha256 = "18l6mrvm2vmwm77ckcnbjvh6ybvn72rhrb799d4qzwac4x2ifl7g";
+          stripLen = 1;
+        })
+
+        # Fix musl build.
+        (fetchpatch {
+          url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+          relative = "llvm";
+          hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+        })
+
+        # Backport gcc-13 fixes with missing includes.
+        (fetchpatch {
+          name = "signals-gcc-13.patch";
+          url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
+          hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
+          stripLen = 1;
+        })
+        (fetchpatch {
+          name = "base64-gcc-13.patch";
+          url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
+          hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
+          stripLen = 1;
+        })
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/13/llvm/default.nix b/pkgs/development/compilers/llvm/13/llvm/default.nix
deleted file mode 100644
index 58e742b9b41ea..0000000000000
--- a/pkgs/development/compilers/llvm/13/llvm/default.nix
+++ /dev/null
@@ -1,315 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, src
-, fetchpatch
-, cmake
-, python3
-, libffi
-, enableGoldPlugin ? libbfd.hasPluginAPI
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, which
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? stdenv.isLinux && (!stdenv.isx86_32) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-# broken for the armv7l builder
-, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
-, enablePolly ? false
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in python3.withPackages checkDeps
-  else python3;
-
-in stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  inherit src;
-  sourceRoot = "${src.name}/${pname}";
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake python ]
-    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = optionals (stdenv.hostPlatform == stdenv.buildPlatform) [ ncurses ]
-    ++ [ zlib ];
-
-  nativeCheckInputs = [ which ];
-
-  patches = [
-    # When cross-compiling we configure llvm-config-native with an approximation
-    # of the flags used for the normal LLVM build. To avoid the need for building
-    # a native libLLVM.so (which would fail) we force llvm-config to be linked
-    # statically against the necessary LLVM components always.
-    ../../common/llvm/llvm-config-link-static.patch
-
-    ./gnu-install-dirs.patch
-
-    # Fix random compiler crashes: https://bugs.llvm.org/show_bug.cgi?id=50611
-    (fetchpatch {
-      url = "https://raw.githubusercontent.com/archlinux/svntogit-packages/4764a4f8c920912a2bfd8b0eea57273acfe0d8a8/trunk/no-strict-aliasing-DwarfCompileUnit.patch";
-      sha256 = "18l6mrvm2vmwm77ckcnbjvh6ybvn72rhrb799d4qzwac4x2ifl7g";
-      stripLen = 1;
-    })
-
-    # Fix musl build.
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
-      relative = "llvm";
-      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
-    })
-
-    # Backport gcc-13 fixes with missing includes.
-    (fetchpatch {
-      name = "signals-gcc-13.patch";
-      url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
-      hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
-      stripLen = 1;
-    })
-    (fetchpatch {
-      name = "base64-gcc-13.patch";
-      url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
-      hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
-      stripLen = 1;
-    })
-  ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
-    )
-  '';
-
-  # hacky fix: created binaries need to be run before installation
-  preBuild = ''
-    mkdir -p $out/
-    ln -sv $PWD/lib $out
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  hardeningDisable = [ "trivialautovarinit" ];
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals (enableGoldPlugin) [
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postBuild = ''
-    rm -fR $out
-  '';
-
-  preCheck = ''
-    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
-  '';
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  buildPhase = ''
-    make docs-llvm-man
-  '';
-
-  propagatedBuildInputs = [];
-
-  installPhase = ''
-    make -C docs install
-  '';
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})
diff --git a/pkgs/development/compilers/llvm/14/default.nix b/pkgs/development/compilers/llvm/14/default.nix
index 588dc8fffefdd..f7368050d6149 100644
--- a/pkgs/development/compilers/llvm/14/default.nix
+++ b/pkgs/development/compilers/llvm/14/default.nix
@@ -1,6 +1,6 @@
 { lowPrio, newScope, pkgs, lib, stdenv, cmake
 , preLibcCrossHeaders
-, libxml2, python3, fetchFromGitHub, substitute, substituteAll, overrideCC, wrapCCWith, wrapBintoolsWith
+, libxml2, python3, fetchFromGitHub, substitute, substituteAll, fetchpatch, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
 , targetLlvm
@@ -80,7 +80,26 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        ./llvm/gnu-install-dirs.patch
+
+        # Fix musl build.
+        (fetchpatch {
+          url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+          relative = "llvm";
+          hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+        })
+        # fix RuntimeDyld usage on aarch64-linux (e.g. python312Packages.numba tests)
+        (fetchpatch {
+          url = "https://github.com/llvm/llvm-project/commit/2e1b838a889f9793d4bcd5dbfe10db9796b77143.patch";
+          relative = "llvm";
+          hash = "sha256-Ot45P/iwaR4hkcM3xtLwfryQNgHI6pv6ADjv98tgdZA=";
+        })
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/14/llvm/default.nix b/pkgs/development/compilers/llvm/14/llvm/default.nix
deleted file mode 100644
index 124d07e4bb2b1..0000000000000
--- a/pkgs/development/compilers/llvm/14/llvm/default.nix
+++ /dev/null
@@ -1,323 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, monorepoSrc
-, runCommand
-, fetchpatch
-, cmake
-, python3
-, libffi
-, enableGoldPlugin ? libbfd.hasPluginAPI
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, which
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? stdenv.isLinux && (!stdenv.isx86_32) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-# broken for the armv7l builder
-, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
-, enablePolly ? true
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in python3.withPackages checkDeps
-  else python3;
-
-in stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = runCommand "${pname}-src-${version}" {} (''
-    mkdir -p "$out"
-    cp -r ${monorepoSrc}/cmake "$out"
-    cp -r ${monorepoSrc}/${pname} "$out"
-    cp -r ${monorepoSrc}/third-party "$out"
-  '' + lib.optionalString enablePolly ''
-    chmod u+w "$out/${pname}/tools"
-    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
-  '');
-
-  sourceRoot = "${src.name}/${pname}";
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake python ]
-    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = [ ncurses zlib ];
-
-  nativeCheckInputs = [ which ];
-
-  patches = [
-    ./gnu-install-dirs.patch
-
-    # Fix musl build.
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
-      relative = "llvm";
-      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
-    })
-    # fix RuntimeDyld usage on aarch64-linux (e.g. python312Packages.numba tests)
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/2e1b838a889f9793d4bcd5dbfe10db9796b77143.patch";
-      relative = "llvm";
-      hash = "sha256-Ot45P/iwaR4hkcM3xtLwfryQNgHI6pv6ADjv98tgdZA=";
-    })
-  ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-dwarfdump/X86/prettyprint_types.s
-    rm test/tools/llvm-dwarfdump/X86/simplified-template-names.s
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + optionalString stdenv.hostPlatform.isRiscV ''
-    rm test/ExecutionEngine/frem.ll
-    rm test/ExecutionEngine/mov64zext32.ll
-    rm test/ExecutionEngine/test-interp-vec-arithm_float.ll
-    rm test/ExecutionEngine/test-interp-vec-arithm_int.ll
-    rm test/ExecutionEngine/test-interp-vec-logical.ll
-    rm test/ExecutionEngine/test-interp-vec-setcond-fp.ll
-    rm test/ExecutionEngine/test-interp-vec-setcond-int.ll
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "CrashRecoveryTest.cpp" ""
-    rm unittests/Support/CrashRecoveryTest.cpp
-    substituteInPlace unittests/ExecutionEngine/Orc/CMakeLists.txt \
-      --replace "OrcCAPITest.cpp" ""
-    rm unittests/ExecutionEngine/Orc/OrcCAPITest.cpp
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
-    )
-  '';
-
-  # hacky fix: created binaries need to be run before installation
-  preBuild = ''
-    mkdir -p $out/
-    ln -sv $PWD/lib $out
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  hardeningDisable = [ "trivialautovarinit" ];
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    "-DLLVM_LINK_LLVM_DYLIB=off"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals (enableGoldPlugin) [
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postBuild = ''
-    rm -fR $out
-  '';
-
-  preCheck = ''
-    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
-  '';
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  # For the update script:
-  passthru.monorepoSrc = monorepoSrc;
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  buildPhase = ''
-    make docs-llvm-man
-  '';
-
-  propagatedBuildInputs = [];
-
-  installPhase = ''
-    make -C docs install
-  '';
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})
diff --git a/pkgs/development/compilers/llvm/15/default.nix b/pkgs/development/compilers/llvm/15/default.nix
index bfcbe2b86e247..5003ef32d1ee0 100644
--- a/pkgs/development/compilers/llvm/15/default.nix
+++ b/pkgs/development/compilers/llvm/15/default.nix
@@ -86,7 +86,64 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        ./llvm/gnu-install-dirs.patch
+
+        # Running the tests involves invoking binaries (like `opt`) that depend on
+        # the LLVM dylibs and reference them by absolute install path (i.e. their
+        # nix store path).
+        #
+        # Because we have not yet run the install phase (we're running these tests
+        # as part of `checkPhase` instead of `installCheckPhase`) these absolute
+        # paths do not exist yet; to work around this we point the loader (`ld` on
+        # unix, `dyld` on macOS) at the `lib` directory which will later become this
+        # package's `lib` output.
+        #
+        # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
+        # dir but:
+        #   - this doesn't generalize well to other platforms; `lit` doesn't forward
+        #     `DYLD_LIBRARY_PATH` (macOS):
+        #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
+        #   - even if `lit` forwarded this env var, we actually cannot set
+        #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
+        #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
+        #     "protected processes" (i.e. the python interpreter that runs `lit`):
+        #     https://stackoverflow.com/a/35570229
+        #   - other LLVM subprojects deal with this issue by having their `lit`
+        #     configuration set these env vars for us; it makes sense to do the same
+        #     for LLVM:
+        #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
+        #
+        # !!! TODO: look into upstreaming this patch
+        ./llvm/llvm-lit-cfg-add-libs-to-dylib-path.patch
+
+        # `lit` has a mode where it executes run lines as a shell script which is
+        # constructs; this is problematic for macOS because it means that there's
+        # another process in between `lit` and the binaries being tested. As noted
+        # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
+        # tests fail with dyld errors.
+        #
+        # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
+        # present in the test configuration.
+        #
+        # It's not clear to me why this isn't an issue for LLVM developers running
+        # on macOS (nothing about this _seems_ nix specific)..
+        ./llvm/lit-shell-script-runner-set-dyld-library-path.patch
+
+        # Fix musl build.
+        (fetchpatch {
+          url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+          relative = "llvm";
+          hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+        })
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+
+        # Just like the `llvm-lit-cfg` patch, but for `polly`.
+        ./llvm/polly-lit-cfg-add-libs-to-dylib-path.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/15/llvm/default.nix b/pkgs/development/compilers/llvm/15/llvm/default.nix
deleted file mode 100644
index d7ebcbcf8b760..0000000000000
--- a/pkgs/development/compilers/llvm/15/llvm/default.nix
+++ /dev/null
@@ -1,442 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, monorepoSrc
-, runCommand
-, fetchpatch
-, cmake
-, darwin
-, ninja
-, python3
-, python3Packages
-, libffi
-, enableGoldPlugin ? libbfd.hasPluginAPI
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, which
-, sysctl
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? (!stdenv.isx86_32 /* TODO: why */) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-, enablePFM ? stdenv.isLinux /* PFM only supports Linux */
-  # broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-  # broken for the armv7l builder
-  && !stdenv.hostPlatform.isAarch
-, enablePolly ? true
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    # Note that we _explicitly_ ask for a python interpreter for our host
-    # platform here; the splicing that would ordinarily take care of this for
-    # us does not seem to work once we use `withPackages`.
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in pkgsBuildBuild.targetPackages.python3.withPackages checkDeps
-  else python3;
-
-in stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = runCommand "${pname}-src-${version}" {} (''
-    mkdir -p "$out"
-    cp -r ${monorepoSrc}/cmake "$out"
-    cp -r ${monorepoSrc}/${pname} "$out"
-    cp -r ${monorepoSrc}/third-party "$out"
-  '' + lib.optionalString enablePolly ''
-    chmod u+w "$out/${pname}/tools"
-    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
-  '');
-
-  sourceRoot = "${src.name}/${pname}";
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake ninja python ]
-    ++ optionals enableManpages [
-      # Note: we intentionally use `python3Packages` instead of `python3.pkgs`;
-      # splicing does *not* work with the latter. (TODO: fix)
-      python3Packages.sphinx python3Packages.recommonmark
-    ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = [ ncurses zlib ];
-
-  nativeCheckInputs = [
-    which
-  ] ++ lib.optional stdenv.isDarwin sysctl;
-
-  patches = [
-    ./gnu-install-dirs.patch
-
-    # Running the tests involves invoking binaries (like `opt`) that depend on
-    # the LLVM dylibs and reference them by absolute install path (i.e. their
-    # nix store path).
-    #
-    # Because we have not yet run the install phase (we're running these tests
-    # as part of `checkPhase` instead of `installCheckPhase`) these absolute
-    # paths do not exist yet; to work around this we point the loader (`ld` on
-    # unix, `dyld` on macOS) at the `lib` directory which will later become this
-    # package's `lib` output.
-    #
-    # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
-    # dir but:
-    #   - this doesn't generalize well to other platforms; `lit` doesn't forward
-    #     `DYLD_LIBRARY_PATH` (macOS):
-    #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
-    #   - even if `lit` forwarded this env var, we actually cannot set
-    #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
-    #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
-    #     "protected processes" (i.e. the python interpreter that runs `lit`):
-    #     https://stackoverflow.com/a/35570229
-    #   - other LLVM subprojects deal with this issue by having their `lit`
-    #     configuration set these env vars for us; it makes sense to do the same
-    #     for LLVM:
-    #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
-    #
-    # !!! TODO: look into upstreaming this patch
-    ./llvm-lit-cfg-add-libs-to-dylib-path.patch
-
-    # `lit` has a mode where it executes run lines as a shell script which is
-    # constructs; this is problematic for macOS because it means that there's
-    # another process in between `lit` and the binaries being tested. As noted
-    # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
-    # tests fail with dyld errors.
-    #
-    # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
-    # present in the test configuration.
-    #
-    # It's not clear to me why this isn't an issue for LLVM developers running
-    # on macOS (nothing about this _seems_ nix specific)..
-    ./lit-shell-script-runner-set-dyld-library-path.patch
-
-    # Fix musl build.
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
-      relative = "llvm";
-      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
-    })
-  ] ++ lib.optionals enablePolly [
-    ./gnu-install-dirs-polly.patch
-
-    # Just like the `llvm-lit-cfg` patch, but for `polly`.
-    ./polly-lit-cfg-add-libs-to-dylib-path.patch
-  ];
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-
-    # As of LLVM 15, marked as XFAIL on arm64 macOS but lit doesn't seem to pick
-    # this up: https://github.com/llvm/llvm-project/blob/c344d97a125b18f8fed0a64aace73c49a870e079/llvm/test/MC/ELF/cfi-version.ll#L7
-    rm test/MC/ELF/cfi-version.ll
-
-    # This test tries to call `sw_vers` by absolute path (`/usr/bin/sw_vers`)
-    # and thus fails under the sandbox:
-    substituteInPlace unittests/Support/Host.cpp \
-      --replace '/usr/bin/sw_vers' "${(builtins.toString darwin.DarwinTools) + "/bin/sw_vers" }"
-  '' + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86) ''
-    # This test tries to call the intrinsics `@llvm.roundeven.f32` and
-    # `@llvm.roundeven.f64` which seem to (incorrectly?) lower to `roundevenf`
-    # and `roundeven` on x86_64 macOS.
-    #
-    # However these functions are glibc specific so the test fails:
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundevenf.html
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundeven.html
-    #
-    # TODO(@rrbutani): this seems to run fine on `aarch64-darwin`, why does it
-    # pass there?
-    substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
-      --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
-      --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
-
-    # This test fails on darwin x86_64 because `sw_vers` reports a different
-    # macOS version than what LLVM finds by reading
-    # `/System/Library/CoreServices/SystemVersion.plist` (which is passed into
-    # the sandbox on macOS).
-    #
-    # The `sw_vers` provided by nixpkgs reports the macOS version associated
-    # with the `CoreFoundation` framework with which it was built. Because
-    # nixpkgs pins the SDK for `aarch64-darwin` and `x86_64-darwin` what
-    # `sw_vers` reports is not guaranteed to match the macOS version of the host
-    # that's building this derivation.
-    #
-    # Astute readers will note that we only _patch_ this test on aarch64-darwin
-    # (to use the nixpkgs provided `sw_vers`) instead of disabling it outright.
-    # So why does this test pass on aarch64?
-    #
-    # Well, it seems that `sw_vers` on aarch64 actually links against the _host_
-    # CoreFoundation framework instead of the nixpkgs provided one.
-    #
-    # Not entirely sure what the right fix is here. I'm assuming aarch64
-    # `sw_vers` doesn't intentionally link against the host `CoreFoundation`
-    # (still digging into how this ends up happening, will follow up) but that
-    # aside I think the more pertinent question is: should we be patching LLVM's
-    # macOS version detection logic to use `sw_vers` instead of reading host
-    # paths? This *is* a way in which details about builder machines can creep
-    # into the artifacts that are produced, affecting reproducibility, but it's
-    # not clear to me when/where/for what this even gets used in LLVM.
-    #
-    # TODO(@rrbutani): fix/follow-up
-    substituteInPlace unittests/Support/Host.cpp \
-      --replace "getMacOSHostVersion" "DISABLED_getMacOSHostVersion"
-
-    # This test fails with a `dysmutil` crash; have not yet dug into what's
-    # going on here (TODO(@rrbutani)).
-    rm test/tools/dsymutil/ARM/obfuscated.test
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
-    # timing-based tests are trouble
-    rm utils/lit/tests/googletest-timeout.py
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-dwarfdump/X86/prettyprint_types.s
-    rm test/tools/llvm-dwarfdump/X86/simplified-template-names.s
-
-    # !!! Note: these tests are removed in LLVM 16.
-    #
-    # See here for context: https://github.com/NixOS/nixpkgs/pull/194634#discussion_r999790443
-    rm test/CodeGen/RISCV/rv32zbp.ll
-    rm test/CodeGen/RISCV/rv64zbp.ll
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS="-svj''${NIX_BUILD_CORES} --no-progress-bar"
-    )
-  '';
-
-  # Defensive check: some paths (that we make symlinks to) depend on the release
-  # version, for example:
-  #  - https://github.com/llvm/llvm-project/blob/406bde9a15136254f2b10d9ef3a42033b3cb1b16/clang/lib/Headers/CMakeLists.txt#L185
-  #
-  # So we want to sure that the version in the source matches the release
-  # version we were given.
-  #
-  # We do this check here, in the LLVM build, because it happens early.
-  postConfigure = let
-    v = lib.versions;
-    major = v.major release_version;
-    minor = v.minor release_version;
-    patch = v.patch release_version;
-  in ''
-    # $1: part, $2: expected
-    check_version() {
-      part="''${1^^}"
-      part="$(cat include/llvm/Config/llvm-config.h  | grep "#define LLVM_VERSION_''${part} " | cut -d' ' -f3)"
-
-      if [[ "$part" != "$2" ]]; then
-        echo >&2 \
-          "mismatch in the $1 version! we have version ${release_version}" \
-          "and expected the $1 version to be '$2'; the source has '$part' instead"
-        exit 3
-      fi
-    }
-
-    check_version major ${major}
-    check_version minor ${minor}
-    check_version patch ${patch}
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  hardeningDisable = [ "trivialautovarinit" ];
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_PACKAGE_DIR=${placeholder "dev"}/lib/cmake/llvm"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    "-DLLVM_LINK_LLVM_DYLIB=off"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals (enableGoldPlugin) [
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  # For the update script:
-  passthru.monorepoSrc = monorepoSrc;
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  propagatedBuildInputs = [];
-
-  ninjaFlags = [ "docs-llvm-man" ];
-  installTargets = [ "install-docs-llvm-man" ];
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})
diff --git a/pkgs/development/compilers/llvm/16/default.nix b/pkgs/development/compilers/llvm/16/default.nix
index 5dd07d77cf8c6..79d5f8589044c 100644
--- a/pkgs/development/compilers/llvm/16/default.nix
+++ b/pkgs/development/compilers/llvm/16/default.nix
@@ -87,7 +87,57 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        ./llvm/gnu-install-dirs.patch
+
+        # Running the tests involves invoking binaries (like `opt`) that depend on
+        # the LLVM dylibs and reference them by absolute install path (i.e. their
+        # nix store path).
+        #
+        # Because we have not yet run the install phase (we're running these tests
+        # as part of `checkPhase` instead of `installCheckPhase`) these absolute
+        # paths do not exist yet; to work around this we point the loader (`ld` on
+        # unix, `dyld` on macOS) at the `lib` directory which will later become this
+        # package's `lib` output.
+        #
+        # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
+        # dir but:
+        #   - this doesn't generalize well to other platforms; `lit` doesn't forward
+        #     `DYLD_LIBRARY_PATH` (macOS):
+        #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
+        #   - even if `lit` forwarded this env var, we actually cannot set
+        #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
+        #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
+        #     "protected processes" (i.e. the python interpreter that runs `lit`):
+        #     https://stackoverflow.com/a/35570229
+        #   - other LLVM subprojects deal with this issue by having their `lit`
+        #     configuration set these env vars for us; it makes sense to do the same
+        #     for LLVM:
+        #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
+        #
+        # !!! TODO: look into upstreaming this patch
+        ./llvm/llvm-lit-cfg-add-libs-to-dylib-path.patch
+
+        # `lit` has a mode where it executes run lines as a shell script which is
+        # constructs; this is problematic for macOS because it means that there's
+        # another process in between `lit` and the binaries being tested. As noted
+        # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
+        # tests fail with dyld errors.
+        #
+        # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
+        # present in the test configuration.
+        #
+        # It's not clear to me why this isn't an issue for LLVM developers running
+        # on macOS (nothing about this _seems_ nix specific)..
+        ./llvm/lit-shell-script-runner-set-dyld-library-path.patch
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+
+        # Just like the `llvm-lit-cfg` patch, but for `polly`.
+        ./llvm/polly-lit-cfg-add-libs-to-dylib-path.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/16/llvm/default.nix b/pkgs/development/compilers/llvm/16/llvm/default.nix
deleted file mode 100644
index 0a8d877ba83c8..0000000000000
--- a/pkgs/development/compilers/llvm/16/llvm/default.nix
+++ /dev/null
@@ -1,435 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, monorepoSrc
-, runCommand
-, cmake
-, darwin
-, ninja
-, python3
-, python3Packages
-, libffi
-# TODO: Gold plugin on LLVM16 has a severe memory corruption bug: https://github.com/llvm/llvm-project/issues/61350.
-, enableGoldPlugin ? false
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, which
-, sysctl
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? (!stdenv.isx86_32 /* TODO: why */) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-, enablePFM ? stdenv.isLinux /* PFM only supports Linux */
-  # broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-  # broken for the armv7l builder
-  && !stdenv.hostPlatform.isAarch
-, enablePolly ? true
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    # Note that we _explicitly_ ask for a python interpreter for our host
-    # platform here; the splicing that would ordinarily take care of this for
-    # us does not seem to work once we use `withPackages`.
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in pkgsBuildBuild.targetPackages.python3.withPackages checkDeps
-  else python3;
-
-in
-  assert (lib.assertMsg (!enableGoldPlugin) "Gold plugin cannot be enabled on LLVM16 due to a upstream issue: https://github.com/llvm/llvm-project/issues/61350");
-  stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = runCommand "${pname}-src-${version}" {} (''
-    mkdir -p "$out"
-    cp -r ${monorepoSrc}/cmake "$out"
-    cp -r ${monorepoSrc}/${pname} "$out"
-    cp -r ${monorepoSrc}/third-party "$out"
-  '' + lib.optionalString enablePolly ''
-    chmod u+w "$out/${pname}/tools"
-    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
-  '');
-
-  sourceRoot = "${src.name}/${pname}";
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake ninja python ]
-    ++ optionals enableManpages [
-      # Note: we intentionally use `python3Packages` instead of `python3.pkgs`;
-      # splicing does *not* work with the latter. (TODO: fix)
-      python3Packages.sphinx python3Packages.recommonmark
-    ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = [ ncurses zlib ];
-
-  nativeCheckInputs = [
-    which
-  ] ++ lib.optional stdenv.isDarwin sysctl;
-
-  patches = [
-    ./gnu-install-dirs.patch
-
-    # Running the tests involves invoking binaries (like `opt`) that depend on
-    # the LLVM dylibs and reference them by absolute install path (i.e. their
-    # nix store path).
-    #
-    # Because we have not yet run the install phase (we're running these tests
-    # as part of `checkPhase` instead of `installCheckPhase`) these absolute
-    # paths do not exist yet; to work around this we point the loader (`ld` on
-    # unix, `dyld` on macOS) at the `lib` directory which will later become this
-    # package's `lib` output.
-    #
-    # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
-    # dir but:
-    #   - this doesn't generalize well to other platforms; `lit` doesn't forward
-    #     `DYLD_LIBRARY_PATH` (macOS):
-    #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
-    #   - even if `lit` forwarded this env var, we actually cannot set
-    #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
-    #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
-    #     "protected processes" (i.e. the python interpreter that runs `lit`):
-    #     https://stackoverflow.com/a/35570229
-    #   - other LLVM subprojects deal with this issue by having their `lit`
-    #     configuration set these env vars for us; it makes sense to do the same
-    #     for LLVM:
-    #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
-    #
-    # !!! TODO: look into upstreaming this patch
-    ./llvm-lit-cfg-add-libs-to-dylib-path.patch
-
-    # `lit` has a mode where it executes run lines as a shell script which is
-    # constructs; this is problematic for macOS because it means that there's
-    # another process in between `lit` and the binaries being tested. As noted
-    # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
-    # tests fail with dyld errors.
-    #
-    # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
-    # present in the test configuration.
-    #
-    # It's not clear to me why this isn't an issue for LLVM developers running
-    # on macOS (nothing about this _seems_ nix specific)..
-    ./lit-shell-script-runner-set-dyld-library-path.patch
-  ] ++ lib.optionals enablePolly [
-    ./gnu-install-dirs-polly.patch
-
-    # Just like the `llvm-lit-cfg` patch, but for `polly`.
-    ./polly-lit-cfg-add-libs-to-dylib-path.patch
-  ];
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-
-    # As of LLVM 15, marked as XFAIL on arm64 macOS but lit doesn't seem to pick
-    # this up: https://github.com/llvm/llvm-project/blob/c344d97a125b18f8fed0a64aace73c49a870e079/llvm/test/MC/ELF/cfi-version.ll#L7
-    rm test/MC/ELF/cfi-version.ll
-
-    # This test tries to call `sw_vers` by absolute path (`/usr/bin/sw_vers`)
-    # and thus fails under the sandbox:
-    substituteInPlace unittests/TargetParser/Host.cpp \
-      --replace '/usr/bin/sw_vers' "${(builtins.toString darwin.DarwinTools) + "/bin/sw_vers" }"
-
-    # This test tries to call the intrinsics `@llvm.roundeven.f32` and
-    # `@llvm.roundeven.f64` which seem to (incorrectly?) lower to `roundevenf`
-    # and `roundeven` on macOS.
-    #
-    # However these functions are glibc specific so the test fails:
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundevenf.html
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundeven.html
-    #
-    substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
-      --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
-      --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
-  '' + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86) ''
-    # This test fails on darwin x86_64 because `sw_vers` reports a different
-    # macOS version than what LLVM finds by reading
-    # `/System/Library/CoreServices/SystemVersion.plist` (which is passed into
-    # the sandbox on macOS).
-    #
-    # The `sw_vers` provided by nixpkgs reports the macOS version associated
-    # with the `CoreFoundation` framework with which it was built. Because
-    # nixpkgs pins the SDK for `aarch64-darwin` and `x86_64-darwin` what
-    # `sw_vers` reports is not guaranteed to match the macOS version of the host
-    # that's building this derivation.
-    #
-    # Astute readers will note that we only _patch_ this test on aarch64-darwin
-    # (to use the nixpkgs provided `sw_vers`) instead of disabling it outright.
-    # So why does this test pass on aarch64?
-    #
-    # Well, it seems that `sw_vers` on aarch64 actually links against the _host_
-    # CoreFoundation framework instead of the nixpkgs provided one.
-    #
-    # Not entirely sure what the right fix is here. I'm assuming aarch64
-    # `sw_vers` doesn't intentionally link against the host `CoreFoundation`
-    # (still digging into how this ends up happening, will follow up) but that
-    # aside I think the more pertinent question is: should we be patching LLVM's
-    # macOS version detection logic to use `sw_vers` instead of reading host
-    # paths? This *is* a way in which details about builder machines can creep
-    # into the artifacts that are produced, affecting reproducibility, but it's
-    # not clear to me when/where/for what this even gets used in LLVM.
-    #
-    # TODO(@rrbutani): fix/follow-up
-    substituteInPlace unittests/TargetParser/Host.cpp \
-      --replace "getMacOSHostVersion" "DISABLED_getMacOSHostVersion"
-
-    # This test fails with a `dysmutil` crash; have not yet dug into what's
-    # going on here (TODO(@rrbutani)).
-    rm test/tools/dsymutil/ARM/obfuscated.test
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
-
-    # Fails in the presence of anti-virus software or other intrusion-detection software that
-    # modifies the atime when run. See #284056.
-    rm test/tools/llvm-objcopy/ELF/strip-preserve-atime.test
-
-    # timing-based tests are trouble
-    rm utils/lit/tests/googletest-timeout.py
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-dwarfdump/X86/prettyprint_types.s
-    rm test/tools/llvm-dwarfdump/X86/simplified-template-names.s
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS="-svj''${NIX_BUILD_CORES} --no-progress-bar"
-    )
-  '';
-
-  # Defensive check: some paths (that we make symlinks to) depend on the release
-  # version, for example:
-  #  - https://github.com/llvm/llvm-project/blob/406bde9a15136254f2b10d9ef3a42033b3cb1b16/clang/lib/Headers/CMakeLists.txt#L185
-  #
-  # So we want to sure that the version in the source matches the release
-  # version we were given.
-  #
-  # We do this check here, in the LLVM build, because it happens early.
-  postConfigure = let
-    v = lib.versions;
-    major = v.major release_version;
-    minor = v.minor release_version;
-    patch = v.patch release_version;
-  in ''
-    # $1: part, $2: expected
-    check_version() {
-      part="''${1^^}"
-      part="$(cat include/llvm/Config/llvm-config.h  | grep "#define LLVM_VERSION_''${part} " | cut -d' ' -f3)"
-
-      if [[ "$part" != "$2" ]]; then
-        echo >&2 \
-          "mismatch in the $1 version! we have version ${release_version}" \
-          "and expected the $1 version to be '$2'; the source has '$part' instead"
-        exit 3
-      fi
-    }
-
-    check_version major ${major}
-    check_version minor ${minor}
-    check_version patch ${patch}
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  hardeningDisable = [ "trivialautovarinit" ];
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_PACKAGE_DIR=${placeholder "dev"}/lib/cmake/llvm"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    "-DLLVM_LINK_LLVM_DYLIB=off"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals enableGoldPlugin [
-    # For LLVMgold plugin
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  # For the update script:
-  passthru.monorepoSrc = monorepoSrc;
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  propagatedBuildInputs = [];
-
-  ninjaFlags = [ "docs-llvm-man" ];
-  installTargets = [ "install-docs-llvm-man" ];
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})
diff --git a/pkgs/development/compilers/llvm/17/default.nix b/pkgs/development/compilers/llvm/17/default.nix
index 9f4be2261b0cf..b4039540badf4 100644
--- a/pkgs/development/compilers/llvm/17/default.nix
+++ b/pkgs/development/compilers/llvm/17/default.nix
@@ -82,7 +82,57 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        ./llvm/gnu-install-dirs.patch
+
+        # Running the tests involves invoking binaries (like `opt`) that depend on
+        # the LLVM dylibs and reference them by absolute install path (i.e. their
+        # nix store path).
+        #
+        # Because we have not yet run the install phase (we're running these tests
+        # as part of `checkPhase` instead of `installCheckPhase`) these absolute
+        # paths do not exist yet; to work around this we point the loader (`ld` on
+        # unix, `dyld` on macOS) at the `lib` directory which will later become this
+        # package's `lib` output.
+        #
+        # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
+        # dir but:
+        #   - this doesn't generalize well to other platforms; `lit` doesn't forward
+        #     `DYLD_LIBRARY_PATH` (macOS):
+        #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
+        #   - even if `lit` forwarded this env var, we actually cannot set
+        #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
+        #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
+        #     "protected processes" (i.e. the python interpreter that runs `lit`):
+        #     https://stackoverflow.com/a/35570229
+        #   - other LLVM subprojects deal with this issue by having their `lit`
+        #     configuration set these env vars for us; it makes sense to do the same
+        #     for LLVM:
+        #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
+        #
+        # !!! TODO: look into upstreaming this patch
+        ./llvm/llvm-lit-cfg-add-libs-to-dylib-path.patch
+
+        # `lit` has a mode where it executes run lines as a shell script which is
+        # constructs; this is problematic for macOS because it means that there's
+        # another process in between `lit` and the binaries being tested. As noted
+        # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
+        # tests fail with dyld errors.
+        #
+        # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
+        # present in the test configuration.
+        #
+        # It's not clear to me why this isn't an issue for LLVM developers running
+        # on macOS (nothing about this _seems_ nix specific)..
+        ./llvm/lit-shell-script-runner-set-dyld-library-path.patch
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+
+        # Just like the `llvm-lit-cfg` patch, but for `polly`.
+        ./llvm/polly-lit-cfg-add-libs-to-dylib-path.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/17/llvm/default.nix b/pkgs/development/compilers/llvm/17/llvm/default.nix
deleted file mode 100644
index a045bea9f4728..0000000000000
--- a/pkgs/development/compilers/llvm/17/llvm/default.nix
+++ /dev/null
@@ -1,431 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, monorepoSrc
-, runCommand
-, cmake
-, darwin
-, ninja
-, python3
-, python3Packages
-, libffi
-, enableGoldPlugin ? libbfd.hasPluginAPI
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, which
-, sysctl
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? (!stdenv.isx86_32 /* TODO: why */) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-, enablePFM ? stdenv.isLinux /* PFM only supports Linux */
-  # broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-  # broken for the armv7l builder
-  && !stdenv.hostPlatform.isAarch
-, enablePolly ? true
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    # Note that we _explicitly_ ask for a python interpreter for our host
-    # platform here; the splicing that would ordinarily take care of this for
-    # us does not seem to work once we use `withPackages`.
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in pkgsBuildBuild.targetPackages.python3.withPackages checkDeps
-  else python3;
-
-in
-
-stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = runCommand "${pname}-src-${version}" {} (''
-    mkdir -p "$out"
-    cp -r ${monorepoSrc}/cmake "$out"
-    cp -r ${monorepoSrc}/${pname} "$out"
-    cp -r ${monorepoSrc}/third-party "$out"
-  '' + lib.optionalString enablePolly ''
-    chmod u+w "$out/${pname}/tools"
-    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
-  '');
-
-  sourceRoot = "${src.name}/${pname}";
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake ninja python ]
-    ++ optionals enableManpages [
-      # Note: we intentionally use `python3Packages` instead of `python3.pkgs`;
-      # splicing does *not* work with the latter. (TODO: fix)
-      python3Packages.sphinx python3Packages.recommonmark
-    ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = [ ncurses zlib ];
-
-  nativeCheckInputs = [
-    which
-  ] ++ lib.optional stdenv.isDarwin sysctl;
-
-  patches = [
-    ./gnu-install-dirs.patch
-
-    # Running the tests involves invoking binaries (like `opt`) that depend on
-    # the LLVM dylibs and reference them by absolute install path (i.e. their
-    # nix store path).
-    #
-    # Because we have not yet run the install phase (we're running these tests
-    # as part of `checkPhase` instead of `installCheckPhase`) these absolute
-    # paths do not exist yet; to work around this we point the loader (`ld` on
-    # unix, `dyld` on macOS) at the `lib` directory which will later become this
-    # package's `lib` output.
-    #
-    # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
-    # dir but:
-    #   - this doesn't generalize well to other platforms; `lit` doesn't forward
-    #     `DYLD_LIBRARY_PATH` (macOS):
-    #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
-    #   - even if `lit` forwarded this env var, we actually cannot set
-    #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
-    #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
-    #     "protected processes" (i.e. the python interpreter that runs `lit`):
-    #     https://stackoverflow.com/a/35570229
-    #   - other LLVM subprojects deal with this issue by having their `lit`
-    #     configuration set these env vars for us; it makes sense to do the same
-    #     for LLVM:
-    #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
-    #
-    # !!! TODO: look into upstreaming this patch
-    ./llvm-lit-cfg-add-libs-to-dylib-path.patch
-
-    # `lit` has a mode where it executes run lines as a shell script which is
-    # constructs; this is problematic for macOS because it means that there's
-    # another process in between `lit` and the binaries being tested. As noted
-    # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
-    # tests fail with dyld errors.
-    #
-    # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
-    # present in the test configuration.
-    #
-    # It's not clear to me why this isn't an issue for LLVM developers running
-    # on macOS (nothing about this _seems_ nix specific)..
-    ./lit-shell-script-runner-set-dyld-library-path.patch
-  ] ++ lib.optionals enablePolly [
-    ./gnu-install-dirs-polly.patch
-
-    # Just like the `llvm-lit-cfg` patch, but for `polly`.
-    ./polly-lit-cfg-add-libs-to-dylib-path.patch
-  ];
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-
-    # As of LLVM 15, marked as XFAIL on arm64 macOS but lit doesn't seem to pick
-    # this up: https://github.com/llvm/llvm-project/blob/c344d97a125b18f8fed0a64aace73c49a870e079/llvm/test/MC/ELF/cfi-version.ll#L7
-    rm test/MC/ELF/cfi-version.ll
-
-    # This test tries to call `sw_vers` by absolute path (`/usr/bin/sw_vers`)
-    # and thus fails under the sandbox:
-    substituteInPlace unittests/TargetParser/Host.cpp \
-      --replace '/usr/bin/sw_vers' "${(builtins.toString darwin.DarwinTools) + "/bin/sw_vers" }"
-
-    # This test tries to call the intrinsics `@llvm.roundeven.f32` and
-    # `@llvm.roundeven.f64` which seem to (incorrectly?) lower to `roundevenf`
-    # and `roundeven` on macOS.
-    #
-    # However these functions are glibc specific so the test fails:
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundevenf.html
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundeven.html
-    #
-    substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
-      --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
-      --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
-  '' + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86) ''
-    # This test fails on darwin x86_64 because `sw_vers` reports a different
-    # macOS version than what LLVM finds by reading
-    # `/System/Library/CoreServices/SystemVersion.plist` (which is passed into
-    # the sandbox on macOS).
-    #
-    # The `sw_vers` provided by nixpkgs reports the macOS version associated
-    # with the `CoreFoundation` framework with which it was built. Because
-    # nixpkgs pins the SDK for `aarch64-darwin` and `x86_64-darwin` what
-    # `sw_vers` reports is not guaranteed to match the macOS version of the host
-    # that's building this derivation.
-    #
-    # Astute readers will note that we only _patch_ this test on aarch64-darwin
-    # (to use the nixpkgs provided `sw_vers`) instead of disabling it outright.
-    # So why does this test pass on aarch64?
-    #
-    # Well, it seems that `sw_vers` on aarch64 actually links against the _host_
-    # CoreFoundation framework instead of the nixpkgs provided one.
-    #
-    # Not entirely sure what the right fix is here. I'm assuming aarch64
-    # `sw_vers` doesn't intentionally link against the host `CoreFoundation`
-    # (still digging into how this ends up happening, will follow up) but that
-    # aside I think the more pertinent question is: should we be patching LLVM's
-    # macOS version detection logic to use `sw_vers` instead of reading host
-    # paths? This *is* a way in which details about builder machines can creep
-    # into the artifacts that are produced, affecting reproducibility, but it's
-    # not clear to me when/where/for what this even gets used in LLVM.
-    #
-    # TODO(@rrbutani): fix/follow-up
-    substituteInPlace unittests/TargetParser/Host.cpp \
-      --replace "getMacOSHostVersion" "DISABLED_getMacOSHostVersion"
-
-    # This test fails with a `dysmutil` crash; have not yet dug into what's
-    # going on here (TODO(@rrbutani)).
-    rm test/tools/dsymutil/ARM/obfuscated.test
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
-
-    # Fails in the presence of anti-virus software or other intrusion-detection software that
-    # modifies the atime when run. See #284056.
-    rm test/tools/llvm-objcopy/ELF/strip-preserve-atime.test
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-dwarfdump/X86/prettyprint_types.s
-    rm test/tools/llvm-dwarfdump/X86/simplified-template-names.s
-    rm test/CodeGen/RISCV/attributes.ll
-    rm test/CodeGen/RISCV/xtheadmempair.ll
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS="-svj''${NIX_BUILD_CORES} --no-progress-bar"
-    )
-  '';
-
-  # Defensive check: some paths (that we make symlinks to) depend on the release
-  # version, for example:
-  #  - https://github.com/llvm/llvm-project/blob/406bde9a15136254f2b10d9ef3a42033b3cb1b16/clang/lib/Headers/CMakeLists.txt#L185
-  #
-  # So we want to sure that the version in the source matches the release
-  # version we were given.
-  #
-  # We do this check here, in the LLVM build, because it happens early.
-  postConfigure = let
-    v = lib.versions;
-    major = v.major release_version;
-    minor = v.minor release_version;
-    patch = v.patch release_version;
-  in ''
-    # $1: part, $2: expected
-    check_version() {
-      part="''${1^^}"
-      part="$(cat include/llvm/Config/llvm-config.h  | grep "#define LLVM_VERSION_''${part} " | cut -d' ' -f3)"
-
-      if [[ "$part" != "$2" ]]; then
-        echo >&2 \
-          "mismatch in the $1 version! we have version ${release_version}" \
-          "and expected the $1 version to be '$2'; the source has '$part' instead"
-        exit 3
-      fi
-    }
-
-    check_version major ${major}
-    check_version minor ${minor}
-    check_version patch ${patch}
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_PACKAGE_DIR=${placeholder "dev"}/lib/cmake/llvm"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    "-DLLVM_LINK_LLVM_DYLIB=off"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals enableGoldPlugin [
-    # For LLVMgold plugin
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  # For the update script:
-  passthru.monorepoSrc = monorepoSrc;
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  propagatedBuildInputs = [];
-
-  ninjaFlags = [ "docs-llvm-man" ];
-  installTargets = [ "install-docs-llvm-man" ];
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})
diff --git a/pkgs/development/compilers/llvm/18/default.nix b/pkgs/development/compilers/llvm/18/default.nix
index 3c78cd44fdf58..ea5323db9b0f3 100644
--- a/pkgs/development/compilers/llvm/18/default.nix
+++ b/pkgs/development/compilers/llvm/18/default.nix
@@ -82,7 +82,57 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        ./llvm/gnu-install-dirs.patch
+
+        # Running the tests involves invoking binaries (like `opt`) that depend on
+        # the LLVM dylibs and reference them by absolute install path (i.e. their
+        # nix store path).
+        #
+        # Because we have not yet run the install phase (we're running these tests
+        # as part of `checkPhase` instead of `installCheckPhase`) these absolute
+        # paths do not exist yet; to work around this we point the loader (`ld` on
+        # unix, `dyld` on macOS) at the `lib` directory which will later become this
+        # package's `lib` output.
+        #
+        # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
+        # dir but:
+        #   - this doesn't generalize well to other platforms; `lit` doesn't forward
+        #     `DYLD_LIBRARY_PATH` (macOS):
+        #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
+        #   - even if `lit` forwarded this env var, we actually cannot set
+        #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
+        #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
+        #     "protected processes" (i.e. the python interpreter that runs `lit`):
+        #     https://stackoverflow.com/a/35570229
+        #   - other LLVM subprojects deal with this issue by having their `lit`
+        #     configuration set these env vars for us; it makes sense to do the same
+        #     for LLVM:
+        #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
+        #
+        # !!! TODO: look into upstreaming this patch
+        ./llvm/llvm-lit-cfg-add-libs-to-dylib-path.patch
+
+        # `lit` has a mode where it executes run lines as a shell script which is
+        # constructs; this is problematic for macOS because it means that there's
+        # another process in between `lit` and the binaries being tested. As noted
+        # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
+        # tests fail with dyld errors.
+        #
+        # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
+        # present in the test configuration.
+        #
+        # It's not clear to me why this isn't an issue for LLVM developers running
+        # on macOS (nothing about this _seems_ nix specific)..
+        ./llvm/lit-shell-script-runner-set-dyld-library-path.patch
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+
+        # Just like the `llvm-lit-cfg` patch, but for `polly`.
+        ./llvm/polly-lit-cfg-add-libs-to-dylib-path.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/common/clang/default.nix b/pkgs/development/compilers/llvm/common/clang/default.nix
index 2373795b49fd8..58af0340a1399 100644
--- a/pkgs/development/compilers/llvm/common/clang/default.nix
+++ b/pkgs/development/compilers/llvm/common/clang/default.nix
@@ -71,7 +71,11 @@ let
       "-DCLANG_PSEUDO_GEN=${buildLlvmTools.libclang.dev}/bin/clang-pseudo-gen"
     ]);
 
-    postPatch = (if lib.versionOlder release_version "13" then ''
+    postPatch = ''
+      # Make sure clang passes the correct location of libLTO to ld64
+      substituteInPlace lib/Driver/ToolChains/Darwin.cpp \
+        --replace-fail 'StringRef P = llvm::sys::path::parent_path(D.Dir);' 'StringRef P = "${lib.getLib libllvm}";'
+    '' + (if lib.versionOlder release_version "13" then ''
       sed -i -e 's/DriverArgs.hasArg(options::OPT_nostdlibinc)/true/' \
              -e 's/Args.hasArg(options::OPT_nostdlibinc)/true/' \
              lib/Driver/ToolChains/*.cpp
diff --git a/pkgs/development/compilers/llvm/18/llvm/default.nix b/pkgs/development/compilers/llvm/common/llvm/default.nix
index a9732763e9d7b..0716453c34c94 100644
--- a/pkgs/development/compilers/llvm/18/llvm/default.nix
+++ b/pkgs/development/compilers/llvm/common/llvm/default.nix
@@ -1,6 +1,12 @@
-{ lib, stdenv, llvm_meta
+{ lib
+, stdenv
+, llvm_meta
 , pkgsBuildBuild
-, monorepoSrc
+, pollyPatches ? []
+, patches ? []
+, polly_src ? null
+, src ? null
+, monorepoSrc ? null
 , runCommand
 , cmake
 , darwin
@@ -8,6 +14,8 @@
 , python3
 , python3Packages
 , libffi
+  # TODO: Can this memory corruption bug still occur?
+  # <https://github.com/llvm/llvm-project/issues/61350>
 , enableGoldPlugin ? libbfd.hasPluginAPI
 , libbfd
 , libpfm
@@ -20,7 +28,8 @@
 , sysctl
 , buildLlvmTools
 , debugVersion ? false
-, doCheck ? (!stdenv.isx86_32 /* TODO: why */) && (!stdenv.hostPlatform.isMusl)
+, doCheck ? (if lib.versionOlder release_version "15" then stdenv.isLinux else true)
+  && (!stdenv.isx86_32 /* TODO: why */) && (!stdenv.hostPlatform.isMusl)
   && (stdenv.hostPlatform == stdenv.buildPlatform)
 , enableManpages ? false
 , enableSharedLibraries ? !stdenv.hostPlatform.isStatic
@@ -28,7 +37,7 @@
   # broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
   # broken for the armv7l builder
   && !stdenv.hostPlatform.isAarch
-, enablePolly ? true
+, enablePolly ? lib.versionAtLeast release_version "14"
 }:
 
 let
@@ -64,27 +73,36 @@ let
     in pkgsBuildBuild.targetPackages.python3.withPackages checkDeps
   else python3;
 
+  pname = "llvm";
+
+  src' = if monorepoSrc != null then
+    runCommand "${pname}-src-${version}" {} (''
+      mkdir -p "$out"
+      cp -r ${monorepoSrc}/cmake "$out"
+      cp -r ${monorepoSrc}/${pname} "$out"
+      cp -r ${monorepoSrc}/third-party "$out"
+    '' + lib.optionalString enablePolly ''
+      chmod u+w "$out/${pname}/tools"
+      cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
+    '') else src;
+
+  patches' = patches ++ lib.optionals enablePolly pollyPatches;
 in
 
 stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = runCommand "${pname}-src-${version}" {} (''
-    mkdir -p "$out"
-    cp -r ${monorepoSrc}/cmake "$out"
-    cp -r ${monorepoSrc}/${pname} "$out"
-    cp -r ${monorepoSrc}/third-party "$out"
-  '' + lib.optionalString enablePolly ''
-    chmod u+w "$out/${pname}/tools"
-    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
-  '');
+  inherit pname version;
 
-  sourceRoot = "${src.name}/${pname}";
+  src = src';
+  patches = patches';
+
+  sourceRoot = if lib.versionOlder release_version "13" then null
+    else "${src.name}/${pname}";
 
   outputs = [ "out" "lib" "dev" "python" ];
 
-  nativeBuildInputs = [ cmake ninja python ]
+  nativeBuildInputs = [ cmake ]
+    ++ (lib.optional (lib.versionAtLeast release_version "15") ninja)
+    ++ [ python ]
     ++ optionals enableManpages [
     # Note: we intentionally use `python3Packages` instead of `python3.pkgs`;
     # splicing does *not* work with the latter. (TODO: fix)
@@ -98,66 +116,14 @@ stdenv.mkDerivation (rec {
   buildInputs = [ libxml2 libffi ]
     ++ optional enablePFM libpfm; # exegesis
 
-  propagatedBuildInputs = [ ncurses zlib ];
-
-  nativeCheckInputs = [
-    which
-  ] ++ lib.optional stdenv.isDarwin sysctl;
-
-  patches = [
-    ./gnu-install-dirs.patch
-
-    # Running the tests involves invoking binaries (like `opt`) that depend on
-    # the LLVM dylibs and reference them by absolute install path (i.e. their
-    # nix store path).
-    #
-    # Because we have not yet run the install phase (we're running these tests
-    # as part of `checkPhase` instead of `installCheckPhase`) these absolute
-    # paths do not exist yet; to work around this we point the loader (`ld` on
-    # unix, `dyld` on macOS) at the `lib` directory which will later become this
-    # package's `lib` output.
-    #
-    # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
-    # dir but:
-    #   - this doesn't generalize well to other platforms; `lit` doesn't forward
-    #     `DYLD_LIBRARY_PATH` (macOS):
-    #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
-    #   - even if `lit` forwarded this env var, we actually cannot set
-    #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
-    #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
-    #     "protected processes" (i.e. the python interpreter that runs `lit`):
-    #     https://stackoverflow.com/a/35570229
-    #   - other LLVM subprojects deal with this issue by having their `lit`
-    #     configuration set these env vars for us; it makes sense to do the same
-    #     for LLVM:
-    #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
-    #
-    # !!! TODO: look into upstreaming this patch
-    ./llvm-lit-cfg-add-libs-to-dylib-path.patch
-
-    # `lit` has a mode where it executes run lines as a shell script which is
-    # constructs; this is problematic for macOS because it means that there's
-    # another process in between `lit` and the binaries being tested. As noted
-    # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
-    # tests fail with dyld errors.
-    #
-    # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
-    # present in the test configuration.
-    #
-    # It's not clear to me why this isn't an issue for LLVM developers running
-    # on macOS (nothing about this _seems_ nix specific)..
-    ./lit-shell-script-runner-set-dyld-library-path.patch
-  ] ++ lib.optionals enablePolly [
-    ./gnu-install-dirs-polly.patch
-
-    # Just like the `llvm-lit-cfg` patch, but for `polly`.
-    ./polly-lit-cfg-add-libs-to-dylib-path.patch
-  ];
+  propagatedBuildInputs = (lib.optional (lib.versionAtLeast release_version "14" || stdenv.buildPlatform == stdenv.hostPlatform) ncurses)
+    ++ [ zlib ];
 
-  postPatch = optionalString stdenv.isDarwin ''
+  postPatch = optionalString stdenv.isDarwin (''
     substituteInPlace cmake/modules/AddLLVM.cmake \
       --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
       --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
+  '' + (optionalString (lib.versionAtLeast release_version "15") (''
 
     # As of LLVM 15, marked as XFAIL on arm64 macOS but lit doesn't seem to pick
     # this up: https://github.com/llvm/llvm-project/blob/c344d97a125b18f8fed0a64aace73c49a870e079/llvm/test/MC/ELF/cfi-version.ll#L7
@@ -165,8 +131,13 @@ stdenv.mkDerivation (rec {
 
     # This test tries to call `sw_vers` by absolute path (`/usr/bin/sw_vers`)
     # and thus fails under the sandbox:
+  '' + (if lib.versionAtLeast release_version "16" then ''
     substituteInPlace unittests/TargetParser/Host.cpp \
       --replace '/usr/bin/sw_vers' "${(builtins.toString darwin.DarwinTools) + "/bin/sw_vers" }"
+  '' else ''
+    substituteInPlace unittests/Support/Host.cpp \
+      --replace '/usr/bin/sw_vers' "${(builtins.toString darwin.DarwinTools) + "/bin/sw_vers" }"
+  '') + optionalString (lib.versionAtLeast release_version "16") ''
 
     # This test tries to call the intrinsics `@llvm.roundeven.f32` and
     # `@llvm.roundeven.f64` which seem to (incorrectly?) lower to `roundevenf`
@@ -179,11 +150,32 @@ stdenv.mkDerivation (rec {
     substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
       --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
       --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
+  '' + optionalString (!stdenv.hostPlatform.isx86 && lib.versionAtLeast release_version "18") ''
 
     # fails when run in sandbox
     substituteInPlace unittests/Support/VirtualFileSystemTest.cpp \
       --replace "PhysicalFileSystemWorkingDirFailure" "DISABLED_PhysicalFileSystemWorkingDirFailure"
-  '' + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86) ''
+  ''))) + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86 && lib.versionAtLeast release_version "15") (optionalString (lib.versionOlder release_version "16") ''
+    # This test tries to call the intrinsics `@llvm.roundeven.f32` and
+    # `@llvm.roundeven.f64` which seem to (incorrectly?) lower to `roundevenf`
+    # and `roundeven` on x86_64 macOS.
+    #
+    # However these functions are glibc specific so the test fails:
+    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundevenf.html
+    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundeven.html
+    #
+    # TODO(@rrbutani): this seems to run fine on `aarch64-darwin`, why does it
+    # pass there?
+    substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
+      --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
+      --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
+
+  '' + ((optionalString (lib.versionAtLeast release_version "18") ''
+
+    # fails when run in sandbox
+    substituteInPlace unittests/Support/VirtualFileSystemTest.cpp \
+      --replace "PhysicalFileSystemWorkingDirFailure" "DISABLED_PhysicalFileSystemWorkingDirFailure"
+  '') + ''
     # This test fails on darwin x86_64 because `sw_vers` reports a different
     # macOS version than what LLVM finds by reading
     # `/System/Library/CoreServices/SystemVersion.plist` (which is passed into
@@ -212,13 +204,18 @@ stdenv.mkDerivation (rec {
     # not clear to me when/where/for what this even gets used in LLVM.
     #
     # TODO(@rrbutani): fix/follow-up
+  '' + (if lib.versionAtLeast release_version "16" then ''
     substituteInPlace unittests/TargetParser/Host.cpp \
       --replace "getMacOSHostVersion" "DISABLED_getMacOSHostVersion"
+  '' else ''
+    substituteInPlace unittests/Support/Host.cpp \
+      --replace "getMacOSHostVersion" "DISABLED_getMacOSHostVersion"
+  '') + ''
 
     # This test fails with a `dysmutil` crash; have not yet dug into what's
     # going on here (TODO(@rrbutani)).
     rm test/tools/dsymutil/ARM/obfuscated.test
-  '' + ''
+  '')) + ''
     # FileSystem permissions tests fail with various special bits
     substituteInPlace unittests/Support/CMakeLists.txt \
       --replace "Path.cpp" ""
@@ -226,13 +223,23 @@ stdenv.mkDerivation (rec {
     substituteInPlace unittests/IR/CMakeLists.txt \
       --replace "PassBuilderCallbacksTest.cpp" ""
     rm unittests/IR/PassBuilderCallbacksTest.cpp
+  '' + lib.optionalString (lib.versionAtLeast release_version "13") ''
     rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
+  '' + lib.optionalString (lib.versionOlder release_version "13") ''
+    # TODO: Fix failing tests:
+    rm test/DebugInfo/X86/vla-multi.ll
+  '' + lib.optionalString (lib.versionAtLeast release_version "16") (''
 
     # Fails in the presence of anti-virus software or other intrusion-detection software that
     # modifies the atime when run. See #284056.
     rm test/tools/llvm-objcopy/ELF/strip-preserve-atime.test
+  '' + lib.optionalString (lib.versionOlder release_version "17") ''
+
+  '') + lib.optionalString (lib.versionAtLeast release_version "15" && lib.versionOlder release_version "17") ''
+    # timing-based tests are trouble
+    rm utils/lit/tests/googletest-timeout.py
   '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
+    patch -p1 -i ${./TLI-musl.patch}
     substituteInPlace unittests/Support/CMakeLists.txt \
       --replace "add_subdirectory(DynamicLibrary)" ""
     rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
@@ -245,61 +252,59 @@ stdenv.mkDerivation (rec {
     rm test/DebugInfo/X86/convert-linked.ll
     rm test/tools/dsymutil/X86/op-convert.test
     rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-dwarfdump/X86/prettyprint_types.s
-    rm test/tools/llvm-dwarfdump/X86/simplified-template-names.s
-    rm test/CodeGen/RISCV/attributes.ll
-    rm test/CodeGen/RISCV/xtheadmempair.ll
+    rm test/tools/llvm-objcopy/MachO/universal-object.test
   '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
     # Seems to require certain floating point hardware (NEON?)
     rm test/ExecutionEngine/frem.ll
   '' + ''
     patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
+  '' + (lib.optionalString (lib.versionOlder release_version "13") ''
+    # Tweak tests to ignore namespace part of type to support
+    # gcc-12: https://gcc.gnu.org/PR103598.
+    # The change below mangles strings like:
+    #    CHECK-NEXT: Starting llvm::Function pass manager run.
+    # to:
+    #    CHECK-NEXT: Starting {{.*}}Function pass manager run.
+    for f in \
+      test/Other/new-pass-manager.ll \
+      test/Other/new-pm-O0-defaults.ll \
+      test/Other/new-pm-defaults.ll \
+      test/Other/new-pm-lto-defaults.ll \
+      test/Other/new-pm-thinlto-defaults.ll \
+      test/Other/pass-pipeline-parsing.ll \
+      test/Transforms/Inline/cgscc-incremental-invalidate.ll \
+      test/Transforms/Inline/clear-analyses.ll \
+      test/Transforms/LoopUnroll/unroll-loop-invalidation.ll \
+      test/Transforms/SCCP/ipsccp-preserve-analysis.ll \
+      test/Transforms/SCCP/preserve-analysis.ll \
+      test/Transforms/SROA/dead-inst.ll \
+      test/tools/gold/X86/new-pm.ll \
+      ; do
+      echo "PATCH: $f"
+      substituteInPlace $f \
+        --replace 'Starting llvm::' 'Starting {{.*}}' \
+        --replace 'Finished llvm::' 'Finished {{.*}}'
+    done
+    # gcc-13 fix
+    sed -i '/#include <string>/i#include <cstdint>' \
+      include/llvm/DebugInfo/Symbolize/DIPrinter.h
+  '');
 
-  preConfigure = ''
+  preConfigure = if lib.versionAtLeast release_version "15" then ''
     # Workaround for configure flags that need to have spaces
     cmakeFlagsArray+=(
       -DLLVM_LIT_ARGS="-svj''${NIX_BUILD_CORES} --no-progress-bar"
     )
-  '';
-
-  # Defensive check: some paths (that we make symlinks to) depend on the release
-  # version, for example:
-  #  - https://github.com/llvm/llvm-project/blob/406bde9a15136254f2b10d9ef3a42033b3cb1b16/clang/lib/Headers/CMakeLists.txt#L185
-  #
-  # So we want to sure that the version in the source matches the release
-  # version we were given.
-  #
-  # We do this check here, in the LLVM build, because it happens early.
-  postConfigure = let
-    v = lib.versions;
-    major = v.major release_version;
-    minor = v.minor release_version;
-    patch = v.patch release_version;
-  in ''
-    # $1: part, $2: expected
-    check_version() {
-      part="''${1^^}"
-      part="$(cat include/llvm/Config/llvm-config.h  | grep "#define LLVM_VERSION_''${part} " | cut -d' ' -f3)"
-
-      if [[ "$part" != "$2" ]]; then
-        echo >&2 \
-          "mismatch in the $1 version! we have version ${release_version}" \
-          "and expected the $1 version to be '$2'; the source has '$part' instead"
-        exit 3
-      fi
-    }
-
-    check_version major ${major}
-    check_version minor ${minor}
-    check_version patch ${patch}
+  '' else ''
+    # Workaround for configure flags that need to have spaces
+    cmakeFlagsArray+=(
+      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
+    )
   '';
 
   # E.g. mesa.drivers use the build-id as a cache key (see #93946):
   LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
 
-  hardeningDisable = [ "trivialautovarinit" ];
-
   cmakeBuildType = if debugVersion then "Debug" else "Release";
 
   cmakeFlags = with stdenv; let
@@ -310,8 +315,11 @@ stdenv.mkDerivation (rec {
     #
     # Some flags don't need to be repassed because LLVM already does so (like
     # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
+    flagsForLlvmConfig = (if lib.versionOlder release_version "15" then [
+      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
+    ] else [
       "-DLLVM_INSTALL_PACKAGE_DIR=${placeholder "dev"}/lib/cmake/llvm"
+    ]) ++ [
       "-DLLVM_ENABLE_RTTI=ON"
     ] ++ optionals enableSharedLibraries [
       "-DLLVM_LINK_LLVM_DYLIB=ON"
@@ -327,7 +335,6 @@ stdenv.mkDerivation (rec {
     # Disables building of shared libs, -fPIC is still injected by cc-wrapper
     "-DLLVM_ENABLE_PIC=OFF"
     "-DLLVM_BUILD_STATIC=ON"
-    "-DLLVM_LINK_LLVM_DYLIB=off"
     # libxml2 needs to be disabled because the LLVM build system ignores its .la
     # file and doesn't link zlib as well.
     # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
@@ -338,7 +345,7 @@ stdenv.mkDerivation (rec {
     "-DSPHINX_OUTPUT_MAN=ON"
     "-DSPHINX_OUTPUT_HTML=OFF"
     "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals enableGoldPlugin [
+  ] ++ optionals (enableGoldPlugin) [
     "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
   ] ++ optionals isDarwin [
     "-DLLVM_ENABLE_LIBCXX=ON"
@@ -382,8 +389,15 @@ stdenv.mkDerivation (rec {
     substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
       --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
       --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
+  '' + (if lib.versionOlder release_version "15" then ''
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
+      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
+  '' else ''
     substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
       --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
+  '')
+  + optionalString (stdenv.isDarwin && enableSharedLibraries && lib.versionOlder release_version "18") ''
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
   ''
   + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
     ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
@@ -418,14 +432,11 @@ stdenv.mkDerivation (rec {
       under the "Apache 2.0 License with LLVM exceptions".
     '';
   };
-} // lib.optionalAttrs enableManpages {
+} // lib.optionalAttrs enableManpages ({
   pname = "llvm-manpages";
 
   propagatedBuildInputs = [];
 
-  ninjaFlags = [ "docs-llvm-man" ];
-  installTargets = [ "install-docs-llvm-man" ];
-
   postPatch = null;
   postInstall = null;
 
@@ -436,4 +447,79 @@ stdenv.mkDerivation (rec {
   meta = llvm_meta // {
     description = "man pages for LLVM ${version}";
   };
+} // (if lib.versionOlder release_version "15" then {
+  buildPhase = ''
+    make docs-llvm-man
+  '';
+
+  installPhase = ''
+    make -C docs install
+  '';
+} else {
+  ninjaFlags = [ "docs-llvm-man" ];
+  installTargets = [ "install-docs-llvm-man" ];
+
+  postPatch = null;
+  postInstall = null;
+})) // lib.optionalAttrs (lib.versionOlder release_version "13") {
+  inherit polly_src;
+
+  unpackPhase = ''
+    unpackFile $src
+    mv llvm-${release_version}* llvm
+    sourceRoot=$PWD/llvm
+  '' + optionalString enablePolly ''
+    unpackFile $polly_src
+    mv polly-* $sourceRoot/tools/polly
+  '';
+} // lib.optionalAttrs (lib.versionAtLeast release_version "13") {
+  nativeCheckInputs = [ which ] ++ lib.optional (stdenv.isDarwin && lib.versionAtLeast release_version "15") sysctl;
+} // lib.optionalAttrs (lib.versionOlder release_version "15") {
+  # hacky fix: created binaries need to be run before installation
+  preBuild = ''
+    mkdir -p $out/
+    ln -sv $PWD/lib $out
+  '';
+
+  postBuild = ''
+    rm -fR $out
+  '';
+
+  preCheck = ''
+    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
+  '';
+} // lib.optionalAttrs (lib.versionAtLeast release_version "15") {
+  # Defensive check: some paths (that we make symlinks to) depend on the release
+  # version, for example:
+  #  - https://github.com/llvm/llvm-project/blob/406bde9a15136254f2b10d9ef3a42033b3cb1b16/clang/lib/Headers/CMakeLists.txt#L185
+  #
+  # So we want to sure that the version in the source matches the release
+  # version we were given.
+  #
+  # We do this check here, in the LLVM build, because it happens early.
+  postConfigure = let
+    v = lib.versions;
+    major = v.major release_version;
+    minor = v.minor release_version;
+    patch = v.patch release_version;
+  in ''
+    # $1: part, $2: expected
+    check_version() {
+      part="''${1^^}"
+      part="$(cat include/llvm/Config/llvm-config.h  | grep "#define LLVM_VERSION_''${part} " | cut -d' ' -f3)"
+
+      if [[ "$part" != "$2" ]]; then
+        echo >&2 \
+          "mismatch in the $1 version! we have version ${release_version}" \
+          "and expected the $1 version to be '$2'; the source has '$part' instead"
+        exit 3
+      fi
+    }
+
+    check_version major ${major}
+    check_version minor ${minor}
+    check_version patch ${patch}
+  '';
+} // lib.optionalAttrs (lib.versionOlder release_version "17" || lib.versionAtLeast release_version "18") {
+  hardeningDisable = [ "trivialautovarinit" ];
 })
diff --git a/pkgs/development/compilers/llvm/git/default.nix b/pkgs/development/compilers/llvm/git/default.nix
index 1a34130679db2..c995845fb6b38 100644
--- a/pkgs/development/compilers/llvm/git/default.nix
+++ b/pkgs/development/compilers/llvm/git/default.nix
@@ -87,7 +87,57 @@ in let
 
   in {
 
-    libllvm = callPackage ./llvm {
+    libllvm = callPackage ../common/llvm {
+      patches = [
+        ./llvm/gnu-install-dirs.patch
+
+        # Running the tests involves invoking binaries (like `opt`) that depend on
+        # the LLVM dylibs and reference them by absolute install path (i.e. their
+        # nix store path).
+        #
+        # Because we have not yet run the install phase (we're running these tests
+        # as part of `checkPhase` instead of `installCheckPhase`) these absolute
+        # paths do not exist yet; to work around this we point the loader (`ld` on
+        # unix, `dyld` on macOS) at the `lib` directory which will later become this
+        # package's `lib` output.
+        #
+        # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
+        # dir but:
+        #   - this doesn't generalize well to other platforms; `lit` doesn't forward
+        #     `DYLD_LIBRARY_PATH` (macOS):
+        #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
+        #   - even if `lit` forwarded this env var, we actually cannot set
+        #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
+        #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
+        #     "protected processes" (i.e. the python interpreter that runs `lit`):
+        #     https://stackoverflow.com/a/35570229
+        #   - other LLVM subprojects deal with this issue by having their `lit`
+        #     configuration set these env vars for us; it makes sense to do the same
+        #     for LLVM:
+        #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
+        #
+        # !!! TODO: look into upstreaming this patch
+        ./llvm/llvm-lit-cfg-add-libs-to-dylib-path.patch
+
+        # `lit` has a mode where it executes run lines as a shell script which is
+        # constructs; this is problematic for macOS because it means that there's
+        # another process in between `lit` and the binaries being tested. As noted
+        # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
+        # tests fail with dyld errors.
+        #
+        # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
+        # present in the test configuration.
+        #
+        # It's not clear to me why this isn't an issue for LLVM developers running
+        # on macOS (nothing about this _seems_ nix specific)..
+        ./llvm/lit-shell-script-runner-set-dyld-library-path.patch
+      ];
+      pollyPatches = [
+        ./llvm/gnu-install-dirs-polly.patch
+
+        # Just like the `llvm-lit-cfg` patch, but for `polly`.
+        ./llvm/polly-lit-cfg-add-libs-to-dylib-path.patch
+      ];
       inherit llvm_meta;
     };
 
diff --git a/pkgs/development/compilers/llvm/git/llvm/default.nix b/pkgs/development/compilers/llvm/git/llvm/default.nix
deleted file mode 100644
index 8987103e22fe5..0000000000000
--- a/pkgs/development/compilers/llvm/git/llvm/default.nix
+++ /dev/null
@@ -1,435 +0,0 @@
-{ lib, stdenv, llvm_meta
-, pkgsBuildBuild
-, monorepoSrc
-, runCommand
-, cmake
-, darwin
-, ninja
-, python3
-, python3Packages
-, libffi
-, enableGoldPlugin ? libbfd.hasPluginAPI
-, libbfd
-, libpfm
-, libxml2
-, ncurses
-, version
-, release_version
-, zlib
-, which
-, sysctl
-, buildLlvmTools
-, debugVersion ? false
-, doCheck ? (!stdenv.isx86_32 /* TODO: why */) && (!stdenv.hostPlatform.isMusl)
-  && (stdenv.hostPlatform == stdenv.buildPlatform)
-, enableManpages ? false
-, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
-, enablePFM ? stdenv.isLinux /* PFM only supports Linux */
-  # broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
-  # broken for the armv7l builder
-  && !stdenv.hostPlatform.isAarch
-, enablePolly ? true
-}:
-
-let
-  inherit (lib) optional optionals optionalString;
-
-  # Used when creating a version-suffixed symlink of libLLVM.dylib
-  shortVersion = with lib;
-    concatStringsSep "." (take 1 (splitString "." release_version));
-
-  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
-  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
-  # out `doCheck` as a package level attribute).
-  #
-  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
-  # particular the children it uses to do feature detection.
-  #
-  # This means that python deps we add to `checkDeps` (which the python
-  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
-  # setup hook) are not picked up by `lit` which causes it to skip tests.
-  #
-  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
-  # because this package is shadowed in `$PATH` by the regular `python3`
-  # package.
-  #
-  # So, we "manually" assemble one python derivation for the package to depend
-  # on, taking into account whether checks are enabled or not:
-  python = if doCheck then
-    # Note that we _explicitly_ ask for a python interpreter for our host
-    # platform here; the splicing that would ordinarily take care of this for
-    # us does not seem to work once we use `withPackages`.
-    let
-      checkDeps = ps: with ps; [ psutil ];
-    in pkgsBuildBuild.targetPackages.python3.withPackages checkDeps
-  else python3;
-
-in
-
-stdenv.mkDerivation (rec {
-  pname = "llvm";
-  inherit version;
-
-  src = runCommand "${pname}-src-${version}" {} (''
-    mkdir -p "$out"
-    cp -r ${monorepoSrc}/cmake "$out"
-    cp -r ${monorepoSrc}/${pname} "$out"
-    cp -r ${monorepoSrc}/third-party "$out"
-  '' + lib.optionalString enablePolly ''
-    chmod u+w "$out/${pname}/tools"
-    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
-  '');
-
-  sourceRoot = "${src.name}/${pname}";
-
-  outputs = [ "out" "lib" "dev" "python" ];
-
-  nativeBuildInputs = [ cmake ninja python ]
-    ++ optionals enableManpages [
-    # Note: we intentionally use `python3Packages` instead of `python3.pkgs`;
-    # splicing does *not* work with the latter. (TODO: fix)
-    python3Packages.sphinx
-  ] ++ optionals (lib.versionOlder version "18" && enableManpages) [
-    python3Packages.recommonmark
-  ] ++ optionals (lib.versionAtLeast version "18" && enableManpages) [
-    python3Packages.myst-parser
-  ];
-
-  buildInputs = [ libxml2 libffi ]
-    ++ optional enablePFM libpfm; # exegesis
-
-  propagatedBuildInputs = [ ncurses zlib ];
-
-  nativeCheckInputs = [
-    which
-  ] ++ lib.optional stdenv.isDarwin sysctl;
-
-  patches = [
-    ./gnu-install-dirs.patch
-
-    # Running the tests involves invoking binaries (like `opt`) that depend on
-    # the LLVM dylibs and reference them by absolute install path (i.e. their
-    # nix store path).
-    #
-    # Because we have not yet run the install phase (we're running these tests
-    # as part of `checkPhase` instead of `installCheckPhase`) these absolute
-    # paths do not exist yet; to work around this we point the loader (`ld` on
-    # unix, `dyld` on macOS) at the `lib` directory which will later become this
-    # package's `lib` output.
-    #
-    # Previously we would just set `LD_LIBRARY_PATH` to include the build `lib`
-    # dir but:
-    #   - this doesn't generalize well to other platforms; `lit` doesn't forward
-    #     `DYLD_LIBRARY_PATH` (macOS):
-    #     + https://github.com/llvm/llvm-project/blob/0d89963df354ee309c15f67dc47c8ab3cb5d0fb2/llvm/utils/lit/lit/TestingConfig.py#L26
-    #   - even if `lit` forwarded this env var, we actually cannot set
-    #     `DYLD_LIBRARY_PATH` in the child processes `lit` launches because
-    #     `DYLD_LIBRARY_PATH` (and `DYLD_FALLBACK_LIBRARY_PATH`) is cleared for
-    #     "protected processes" (i.e. the python interpreter that runs `lit`):
-    #     https://stackoverflow.com/a/35570229
-    #   - other LLVM subprojects deal with this issue by having their `lit`
-    #     configuration set these env vars for us; it makes sense to do the same
-    #     for LLVM:
-    #     + https://github.com/llvm/llvm-project/blob/4c106cfdf7cf7eec861ad3983a3dd9a9e8f3a8ae/clang-tools-extra/test/Unit/lit.cfg.py#L22-L31
-    #
-    # !!! TODO: look into upstreaming this patch
-    ./llvm-lit-cfg-add-libs-to-dylib-path.patch
-
-    # `lit` has a mode where it executes run lines as a shell script which is
-    # constructs; this is problematic for macOS because it means that there's
-    # another process in between `lit` and the binaries being tested. As noted
-    # above, this means that `DYLD_LIBRARY_PATH` is cleared which means that our
-    # tests fail with dyld errors.
-    #
-    # To get around this we patch `lit` to reintroduce `DYLD_LIBRARY_PATH`, when
-    # present in the test configuration.
-    #
-    # It's not clear to me why this isn't an issue for LLVM developers running
-    # on macOS (nothing about this _seems_ nix specific)..
-    ./lit-shell-script-runner-set-dyld-library-path.patch
-  ] ++ lib.optionals enablePolly [
-    ./gnu-install-dirs-polly.patch
-
-    # Just like the `llvm-lit-cfg` patch, but for `polly`.
-    ./polly-lit-cfg-add-libs-to-dylib-path.patch
-  ];
-
-  postPatch = optionalString stdenv.isDarwin ''
-    substituteInPlace cmake/modules/AddLLVM.cmake \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
-      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
-
-    # As of LLVM 15, marked as XFAIL on arm64 macOS but lit doesn't seem to pick
-    # this up: https://github.com/llvm/llvm-project/blob/c344d97a125b18f8fed0a64aace73c49a870e079/llvm/test/MC/ELF/cfi-version.ll#L7
-    rm test/MC/ELF/cfi-version.ll
-
-    # This test tries to call `sw_vers` by absolute path (`/usr/bin/sw_vers`)
-    # and thus fails under the sandbox:
-    substituteInPlace unittests/TargetParser/Host.cpp \
-      --replace '/usr/bin/sw_vers' "${(builtins.toString darwin.DarwinTools) + "/bin/sw_vers" }"
-
-    # This test tries to call the intrinsics `@llvm.roundeven.f32` and
-    # `@llvm.roundeven.f64` which seem to (incorrectly?) lower to `roundevenf`
-    # and `roundeven` on macOS.
-    #
-    # However these functions are glibc specific so the test fails:
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundevenf.html
-    #   - https://www.gnu.org/software/gnulib/manual/html_node/roundeven.html
-    #
-    substituteInPlace test/ExecutionEngine/Interpreter/intrinsics.ll \
-      --replace "%roundeven32 = call float @llvm.roundeven.f32(float 0.000000e+00)" "" \
-      --replace "%roundeven64 = call double @llvm.roundeven.f64(double 0.000000e+00)" ""
-
-    # fails when run in sandbox
-    substituteInPlace unittests/Support/VirtualFileSystemTest.cpp \
-      --replace "PhysicalFileSystemWorkingDirFailure" "DISABLED_PhysicalFileSystemWorkingDirFailure"
-  '' + optionalString (stdenv.isDarwin && stdenv.hostPlatform.isx86) ''
-    # This test fails on darwin x86_64 because `sw_vers` reports a different
-    # macOS version than what LLVM finds by reading
-    # `/System/Library/CoreServices/SystemVersion.plist` (which is passed into
-    # the sandbox on macOS).
-    #
-    # The `sw_vers` provided by nixpkgs reports the macOS version associated
-    # with the `CoreFoundation` framework with which it was built. Because
-    # nixpkgs pins the SDK for `aarch64-darwin` and `x86_64-darwin` what
-    # `sw_vers` reports is not guaranteed to match the macOS version of the host
-    # that's building this derivation.
-    #
-    # Astute readers will note that we only _patch_ this test on aarch64-darwin
-    # (to use the nixpkgs provided `sw_vers`) instead of disabling it outright.
-    # So why does this test pass on aarch64?
-    #
-    # Well, it seems that `sw_vers` on aarch64 actually links against the _host_
-    # CoreFoundation framework instead of the nixpkgs provided one.
-    #
-    # Not entirely sure what the right fix is here. I'm assuming aarch64
-    # `sw_vers` doesn't intentionally link against the host `CoreFoundation`
-    # (still digging into how this ends up happening, will follow up) but that
-    # aside I think the more pertinent question is: should we be patching LLVM's
-    # macOS version detection logic to use `sw_vers` instead of reading host
-    # paths? This *is* a way in which details about builder machines can creep
-    # into the artifacts that are produced, affecting reproducibility, but it's
-    # not clear to me when/where/for what this even gets used in LLVM.
-    #
-    # TODO(@rrbutani): fix/follow-up
-    substituteInPlace unittests/TargetParser/Host.cpp \
-      --replace "getMacOSHostVersion" "DISABLED_getMacOSHostVersion"
-  '' + ''
-    # FileSystem permissions tests fail with various special bits
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "Path.cpp" ""
-    rm unittests/Support/Path.cpp
-    substituteInPlace unittests/IR/CMakeLists.txt \
-      --replace "PassBuilderCallbacksTest.cpp" ""
-    rm unittests/IR/PassBuilderCallbacksTest.cpp
-    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
-
-    # Fails in the presence of anti-virus software or other intrusion-detection software that
-    # modifies the atime when run. See #284056.
-    rm test/tools/llvm-objcopy/ELF/strip-preserve-atime.test
-  '' + optionalString stdenv.hostPlatform.isMusl ''
-    patch -p1 -i ${../../common/llvm/TLI-musl.patch}
-    substituteInPlace unittests/Support/CMakeLists.txt \
-      --replace "add_subdirectory(DynamicLibrary)" ""
-    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
-    # valgrind unhappy with musl or glibc, but fails w/musl only
-    rm test/CodeGen/AArch64/wineh4.mir
-  '' + optionalString stdenv.hostPlatform.isAarch32 ''
-    # skip failing X86 test cases on 32-bit ARM
-    rm test/DebugInfo/X86/convert-debugloc.ll
-    rm test/DebugInfo/X86/convert-inlined.ll
-    rm test/DebugInfo/X86/convert-linked.ll
-    rm test/tools/dsymutil/X86/op-convert.test
-    rm test/tools/gold/X86/split-dwarf.ll
-    rm test/tools/llvm-dwarfdump/X86/prettyprint_types.s
-    rm test/tools/llvm-dwarfdump/X86/simplified-template-names.s
-    rm test/CodeGen/RISCV/attributes.ll
-    rm test/CodeGen/RISCV/xtheadmempair.ll
-  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
-    # Seems to require certain floating point hardware (NEON?)
-    rm test/ExecutionEngine/frem.ll
-  '' + ''
-    patchShebangs test/BugPoint/compile-custom.ll.py
-  '';
-
-  preConfigure = ''
-    # Workaround for configure flags that need to have spaces
-    cmakeFlagsArray+=(
-      -DLLVM_LIT_ARGS="-svj''${NIX_BUILD_CORES} --no-progress-bar"
-    )
-  '';
-
-  # Defensive check: some paths (that we make symlinks to) depend on the release
-  # version, for example:
-  #  - https://github.com/llvm/llvm-project/blob/406bde9a15136254f2b10d9ef3a42033b3cb1b16/clang/lib/Headers/CMakeLists.txt#L185
-  #
-  # So we want to sure that the version in the source matches the release
-  # version we were given.
-  #
-  # We do this check here, in the LLVM build, because it happens early.
-  postConfigure = let
-    v = lib.versions;
-    major = v.major release_version;
-    minor = v.minor release_version;
-    patch = v.patch release_version;
-  in ''
-    # $1: part, $2: expected
-    check_version() {
-      part="''${1^^}"
-      part="$(cat include/llvm/Config/llvm-config.h  | grep "#define LLVM_VERSION_''${part} " | cut -d' ' -f3)"
-
-      if [[ "$part" != "$2" ]]; then
-        echo >&2 \
-          "mismatch in the $1 version! we have version ${release_version}" \
-          "and expected the $1 version to be '$2'; the source has '$part' instead"
-        exit 3
-      fi
-    }
-
-    check_version major ${major}
-    check_version minor ${minor}
-    check_version patch ${patch}
-  '';
-
-  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
-  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
-
-  hardeningDisable = [ "trivialautovarinit" ];
-
-  cmakeBuildType = if debugVersion then "Debug" else "Release";
-
-  cmakeFlags = with stdenv; let
-    # These flags influence llvm-config's BuildVariables.inc in addition to the
-    # general build. We need to make sure these are also passed via
-    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
-    # will return different results from the cross llvm-config.
-    #
-    # Some flags don't need to be repassed because LLVM already does so (like
-    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
-    flagsForLlvmConfig = [
-      "-DLLVM_INSTALL_PACKAGE_DIR=${placeholder "dev"}/lib/cmake/llvm"
-      "-DLLVM_ENABLE_RTTI=ON"
-    ] ++ optionals enableSharedLibraries [
-      "-DLLVM_LINK_LLVM_DYLIB=ON"
-    ];
-  in flagsForLlvmConfig ++ [
-    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
-    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
-    "-DLLVM_ENABLE_FFI=ON"
-    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
-    "-DLLVM_ENABLE_DUMP=ON"
-  ] ++ optionals stdenv.hostPlatform.isStatic [
-    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
-    "-DLLVM_ENABLE_PIC=OFF"
-    "-DLLVM_BUILD_STATIC=ON"
-    "-DLLVM_LINK_LLVM_DYLIB=off"
-    # libxml2 needs to be disabled because the LLVM build system ignores its .la
-    # file and doesn't link zlib as well.
-    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
-    "-DLLVM_ENABLE_LIBXML2=OFF"
-  ] ++ optionals enableManpages [
-    "-DLLVM_BUILD_DOCS=ON"
-    "-DLLVM_ENABLE_SPHINX=ON"
-    "-DSPHINX_OUTPUT_MAN=ON"
-    "-DSPHINX_OUTPUT_HTML=OFF"
-    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
-  ] ++ optionals enableGoldPlugin [
-    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
-  ] ++ optionals isDarwin [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DCAN_TARGET_i386=false"
-  ] ++ optionals ((stdenv.hostPlatform != stdenv.buildPlatform) && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform)) [
-    "-DCMAKE_CROSSCOMPILING=True"
-    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
-    (
-      let
-        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
-        nativeBintools = nativeCC.bintools.bintools;
-        nativeToolchainFlags = [
-          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
-          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
-          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
-          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
-          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
-        ];
-        # We need to repass the custom GNUInstallDirs values, otherwise CMake
-        # will choose them for us, leading to wrong results in llvm-config-native
-        nativeInstallFlags = [
-          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
-          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
-          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
-          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
-          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
-        ];
-      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
-      + lib.concatStringsSep ";" (lib.concatLists [
-        flagsForLlvmConfig
-        nativeToolchainFlags
-        nativeInstallFlags
-      ])
-    )
-  ];
-
-  postInstall = ''
-    mkdir -p $python/share
-    mv $out/share/opt-viewer $python/share/opt-viewer
-    moveToOutput "bin/llvm-config*" "$dev"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
-      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
-      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
-    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
-      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "'"$lib"'")'
-  ''
-  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
-    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
-  ''
-  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
-    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
-  '';
-
-  inherit doCheck;
-
-  checkTarget = "check-all";
-
-  # For the update script:
-  passthru.monorepoSrc = monorepoSrc;
-
-  requiredSystemFeatures = [ "big-parallel" ];
-  meta = llvm_meta // {
-    homepage = "https://llvm.org/";
-    description = "A collection of modular and reusable compiler and toolchain technologies";
-    longDescription = ''
-      The LLVM Project is a collection of modular and reusable compiler and
-      toolchain technologies. Despite its name, LLVM has little to do with
-      traditional virtual machines. The name "LLVM" itself is not an acronym; it
-      is the full name of the project.
-      LLVM began as a research project at the University of Illinois, with the
-      goal of providing a modern, SSA-based compilation strategy capable of
-      supporting both static and dynamic compilation of arbitrary programming
-      languages. Since then, LLVM has grown to be an umbrella project consisting
-      of a number of subprojects, many of which are being used in production by
-      a wide variety of commercial and open source projects as well as being
-      widely used in academic research. Code in the LLVM project is licensed
-      under the "Apache 2.0 License with LLVM exceptions".
-    '';
-  };
-} // lib.optionalAttrs enableManpages {
-  pname = "llvm-manpages";
-
-  propagatedBuildInputs = [];
-
-  ninjaFlags = [ "docs-llvm-man" ];
-  installTargets = [ "install-docs-llvm-man" ];
-
-  postPatch = null;
-  postInstall = null;
-
-  outputs = [ "out" ];
-
-  doCheck = false;
-
-  meta = llvm_meta // {
-    description = "man pages for LLVM ${version}";
-  };
-})