Merge pull request #122655 from Ericson2314/bootstrapping-consistency

treewide: Some LLVM / bootstrapping / cross cleanups especially for consistency

pkgs/development/compilers/llvm/10/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -96,11 +96,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -119,6 +128,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/10/compiler-rt/default.nix

@@ -1,17 +1,18 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
   useLLVM = stdenv.hostPlatform.useLLVM or false;
   bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
   inherit (stdenv.hostPlatform) isMusl;
 
 in
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
-  pname = "compiler-rt";
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
   inherit version;
-  src = fetch pname "1yjqjri753w0fzmxcyz687nvd97sbc9rsqrxzpq720na47hwh3fr";
+  src = fetch "compiler-rt" "1yjqjri753w0fzmxcyz687nvd97sbc9rsqrxzpq720na47hwh3fr";
 
   nativeBuildInputs = [ cmake python3 llvm.dev ];
   buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
@@ -29,14 +30,15 @@ stdenv.mkDerivation rec {
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ lib.optionals (useLLVM || bareMetal) [
+  ] ++ lib.optionals ((useLLVM || bareMetal) && !haveLibc) [
     "-DCMAKE_C_COMPILER_WORKS=ON"
     "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
     "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM && !haveLibc) [
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
   ] ++ lib.optionals (useLLVM) [
     "-DCOMPILER_RT_BUILD_BUILTINS=ON"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
   ] ++ lib.optionals (bareMetal) [
@@ -58,7 +60,6 @@ stdenv.mkDerivation rec {
   ]# ++ lib.optional stdenv.hostPlatform.isMusl ./sanitizers-nongnu.patch
     ++ lib.optional stdenv.hostPlatform.isAarch32 ./armv7l.patch;
 
-
   # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
   # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
   # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd
@@ -89,4 +90,19 @@ stdenv.mkDerivation rec {
     ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
   '';
 
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/10/default.nix

@@ -1,4 +1,5 @@
-{ lowPrio, newScope, pkgs, lib, stdenv, cmake, gccForLibs
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
 , libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
@@ -16,6 +17,12 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "06n1yp638rh24xdxv9v2df0qajxbjz4w59b7dd4ky36drwmpi4yh";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands0 = cc: ''
@@ -31,14 +38,16 @@ let
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
@@ -82,9 +91,13 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
 
     # Below, is the LLVM bootstrapping logic. It handles building a
     # fully LLVM toolchain from scratch. No GCC toolchain should be
@@ -93,7 +106,16 @@ let
     # doesn’t support like LLVM. Probably we should move to some other
     # file.
 
-    bintools = callPackage ./bintools.nix {};
+    bintools-unwrapped = callPackage ./bintools {};
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
 
     lldClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
@@ -112,6 +134,8 @@ let
         echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
       '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
         echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (stdenv.targetPlatform.isAndroid && stdenv.targetPlatform.useLLVM) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
       '' + lib.optionalString stdenv.targetPlatform.isWasm ''
         echo "-fno-exceptions" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands cc;
@@ -120,9 +144,7 @@ let
     lldClangNoLibcxx = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -136,10 +158,7 @@ let
     lldClangNoLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -152,49 +171,74 @@ let
     lldClangNoCompilerRt = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [ ];
       extraBuildCommands = ''
         echo "-nostartfiles" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands0 cc;
     };
 
+    lldClangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      inherit (tools) bintools;
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt ({} //
+    compiler-rt-libc = callPackage ./compiler-rt {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
 
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ ({} //
+    libcxx = callPackage ./libcxx {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
+               else stdenv;
+    };
 
-    libcxxabi = callPackage ./libc++abi ({} //
+    libcxxabi = callPackage ./libcxxabi {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        libunwind = libraries.libunwind;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    libunwind = callPackage ./libunwind {
-
+      inherit llvm_meta;
-    libunwind = callPackage ./libunwind ({} //
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+               else stdenv;
-      }));
+    };
 
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/10/libcxx/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "0v78bfr6h2zifvdqnj2wlfk4pvxzrqn3hg1v6lqk3y12bx9p9xny";
@@ -17,7 +17,9 @@ stdenv.mkDerivation {
 
   patches = [
     ./gnu-install-dirs.patch
-  ] ++ lib.optional stdenv.hostPlatform.isMusl ../../libcxx-0001-musl-hacks.patch;
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
 
   preConfigure = ''
     # Get headers from the cxxabi source so we can see private headers not installed by the cxxabi package
@@ -47,10 +49,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.all;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }

pkgs/development/compilers/llvm/10/libcxxabi/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, cmake, fetch, libcxx, libunwind, llvm, version
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++abi";
+  pname = "libcxxabi";
   inherit version;
 
   src = fetch "libcxxabi" "0yqs722y76cwvmfsq0lb917r9m3fci7bf5z3yzl71yz9n88ghzm9";
@@ -63,11 +63,15 @@ stdenv.mkDerivation {
       ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
     '';
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxxabi.llvm.org/";
-    description = "A new implementation of low level support for a standard C++ library";
+    description = "Provides C++ standard library support";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    maintainers = with lib.maintainers; [ vlstill ];
+      libc++abi is a new implementation of low level support for a standard C++ library.
-    platforms = lib.platforms.all;
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
   };
 }

pkgs/development/compilers/llvm/10/libunwind/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, version, fetch, cmake, fetchpatch
+{ lib, stdenv, llvm_meta, version, fetch, cmake, fetchpatch
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
@@ -17,4 +17,16 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ cmake ];
 
   cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
 }

pkgs/development/compilers/llvm/10/lld/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , buildLlvmTools
 , fetch
 , cmake
@@ -28,10 +28,16 @@ stdenv.mkDerivation rec {
 
   outputs = [ "out" "lib" "dev" ];
 
-  meta = {
+  meta = llvm_meta // {
-    description = "The LLVM Linker";
+    homepage = "https://lld.llvm.org/";
-    homepage    = "https://lld.llvm.org/";
+    description = "The LLVM linker";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    platforms   = lib.platforms.all;
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
   };
 }

pkgs/development/compilers/llvm/10/lldb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , fetch
 , cmake
 , zlib
@@ -76,11 +76,15 @@ stdenv.mkDerivation (rec {
     ln -s $out/bin/llvm-vscode $out/share/vscode/extensions/llvm-org.lldb-vscode-0.1.0/bin
   '';
 
-  meta = with lib; {
+  meta = llvm_meta // {
+    homepage = "https://lldb.llvm.org/";
     description = "A next-generation high-performance debugger";
-    homepage    = "https://lldb.llvm.org";
+    longDescription = ''
-    license     = licenses.ncsa;
+      LLDB is a next generation, high-performance debugger. It is built as a set
-    platforms   = platforms.all;
+      of reusable components which highly leverage existing libraries in the
+      larger LLVM Project, such as the Clang expression parser and LLVM
+      disassembler.
+    '';
   };
 } // lib.optionalAttrs enableManpages {
   pname = "lldb-manpages";
@@ -104,5 +108,7 @@ stdenv.mkDerivation (rec {
 
   doCheck = false;
 
-  meta.description = "man pages for LLDB ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLDB ${version}";
+  };
 })

pkgs/development/compilers/llvm/10/llvm/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , pkgsBuildBuild
 , fetch
 , cmake
@@ -172,12 +172,23 @@ in stdenv.mkDerivation (rec {
   checkTarget = "check-all";
 
   requiredSystemFeatures = [ "big-parallel" ];
-  meta = {
+  meta = llvm_meta // {
-    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = "https://llvm.org/";
-    homepage    = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill ];
+      The LLVM Project is a collection of modular and reusable compiler and
-    platforms   = lib.platforms.all;
+      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";
@@ -199,5 +210,7 @@ in stdenv.mkDerivation (rec {
 
   doCheck = false;
 
-  meta.description = "man pages for LLVM ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
 })

pkgs/development/compilers/llvm/10/openmp.nix

@@ -1,25 +0,0 @@
-{ lib
-, stdenv
-, fetch
-, cmake
-, llvm
-, perl
-, version
-}:
-
-stdenv.mkDerivation rec {
-  pname = "openmp";
-  inherit version;
-
-  src = fetch pname "0i4bn84lkpm5w3qkpvwm5z6jdj8fynp7d3bcasa1xyq4is6757yi";
-
-  nativeBuildInputs = [ cmake perl ];
-  buildInputs = [ llvm ];
-
-  meta = {
-    description = "Components required to build an executable OpenMP program";
-    homepage    = "https://openmp.llvm.org/";
-    license     = lib.licenses.mit;
-    platforms   = lib.platforms.all;
-  };
-}

pkgs/development/compilers/llvm/10/openmp/default.nix

@@ -0,0 +1,34 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, cmake
+, llvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch pname "0i4bn84lkpm5w3qkpvwm5z6jdj8fynp7d3bcasa1xyq4is6757yi";
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [ llvm ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}

pkgs/development/compilers/llvm/11/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -95,11 +95,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -118,6 +127,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/11/compiler-rt/default.nix

@@ -1,17 +1,18 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
   useLLVM = stdenv.hostPlatform.useLLVM or false;
   bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
   inherit (stdenv.hostPlatform) isMusl;
 
 in
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
-  pname = "compiler-rt";
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
   inherit version;
-  src = fetch pname "0x1j8ngf1zj63wlnns9vlibafq48qcm72p4jpaxkmkb4qw0grwfy";
+  src = fetch "compiler-rt" "0x1j8ngf1zj63wlnns9vlibafq48qcm72p4jpaxkmkb4qw0grwfy";
 
   nativeBuildInputs = [ cmake python3 llvm.dev ];
   buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
@@ -29,14 +30,15 @@ stdenv.mkDerivation rec {
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ lib.optionals (useLLVM || bareMetal) [
+  ] ++ lib.optionals ((useLLVM || bareMetal) && !haveLibc) [
     "-DCMAKE_C_COMPILER_WORKS=ON"
     "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
     "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM && !haveLibc) [
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
   ] ++ lib.optionals (useLLVM) [
     "-DCOMPILER_RT_BUILD_BUILTINS=ON"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
   ] ++ lib.optionals (bareMetal) [
@@ -59,7 +61,6 @@ stdenv.mkDerivation rec {
   ]# ++ lib.optional stdenv.hostPlatform.isMusl ./sanitizers-nongnu.patch
     ++ lib.optional stdenv.hostPlatform.isAarch32 ./armv7l.patch;
 
-
   # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
   # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
   # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd
@@ -92,4 +93,19 @@ stdenv.mkDerivation rec {
     ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
   '';
 
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/11/default.nix

@@ -1,4 +1,5 @@
-{ lowPrio, newScope, pkgs, lib, stdenv, cmake, gccForLibs
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
 , libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
@@ -18,6 +19,12 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "18n1w1hkv931xzq02b34wglbv6zd6sd0r5kb8piwvag7klj7qw3n";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands0 = cc: ''
@@ -33,14 +40,16 @@ let
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
@@ -83,9 +92,13 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
 
     # Below, is the LLVM bootstrapping logic. It handles building a
     # fully LLVM toolchain from scratch. No GCC toolchain should be
@@ -94,7 +107,16 @@ let
     # doesn’t support like LLVM. Probably we should move to some other
     # file.
 
-    bintools = callPackage ./bintools.nix {};
+    bintools-unwrapped = callPackage ./bintools {};
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
 
     lldClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
@@ -113,6 +135,8 @@ let
         echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
       '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
         echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (stdenv.targetPlatform.isAndroid && stdenv.targetPlatform.useLLVM) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
       '' + lib.optionalString stdenv.targetPlatform.isWasm ''
         echo "-fno-exceptions" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands cc;
@@ -121,9 +145,7 @@ let
     lldClangNoLibcxx = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -137,10 +159,7 @@ let
     lldClangNoLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -153,49 +172,74 @@ let
     lldClangNoCompilerRt = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [ ];
       extraBuildCommands = ''
         echo "-nostartfiles" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands0 cc;
     };
 
+    lldClangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      inherit (tools) bintools;
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt ({} //
+    compiler-rt-libc = callPackage ./compiler-rt {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
 
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ ({} //
+    libcxx = callPackage ./libcxx {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
+               else stdenv;
+    };
 
-    libcxxabi = callPackage ./libc++abi ({} //
+    libcxxabi = callPackage ./libcxxabi {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        libunwind = libraries.libunwind;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    libunwind = callPackage ./libunwind {
-
+      inherit llvm_meta;
-    libunwind = callPackage ./libunwind ({} //
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+               else stdenv;
-      }));
+    };
 
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/11/libcxx/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, fetch, fetchpatch, cmake, python3, libcxxabi, llvm, fixDarwinDylibNames, version
+{ lib, stdenv, llvm_meta, fetch, fetchpatch, cmake, python3, libcxxabi, llvm, fixDarwinDylibNames, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "1rgqsqpgi0vkga5d7hy0iyfsqgzfz7q1xy7afdfa1snp1qjks8xv";
@@ -25,7 +25,9 @@ stdenv.mkDerivation {
       stripLen = 1;
     })
     ./gnu-install-dirs.patch
-  ] ++ lib.optional stdenv.hostPlatform.isMusl ../../libcxx-0001-musl-hacks.patch;
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
 
   preConfigure = lib.optionalString stdenv.hostPlatform.isMusl ''
     patchShebangs utils/cat_files.py
@@ -50,10 +52,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.all;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }

pkgs/development/compilers/llvm/11/libcxxabi/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, cmake, fetch, libcxx, libunwind, llvm, version
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++abi";
+  pname = "libcxxabi";
   inherit version;
 
   src = fetch "libcxxabi" "1azcf31mxw59hb1x17xncnm3dyw90ylh8rqx462lvypqh3nr6c8l";
@@ -64,11 +64,15 @@ stdenv.mkDerivation {
       ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
     '';
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxxabi.llvm.org/";
-    description = "A new implementation of low level support for a standard C++ library";
+    description = "Provides C++ standard library support";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    maintainers = with lib.maintainers; [ vlstill ];
+      libc++abi is a new implementation of low level support for a standard C++ library.
-    platforms = lib.platforms.all;
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
   };
 }

pkgs/development/compilers/llvm/11/libunwind/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, version, fetch, cmake, fetchpatch
+{ lib, stdenv, llvm_meta, version, fetch, cmake, fetchpatch
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
@@ -17,4 +17,16 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ cmake ];
 
   cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
 }

pkgs/development/compilers/llvm/11/lld/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , buildLlvmTools
 , fetch
 , cmake
@@ -28,10 +28,16 @@ stdenv.mkDerivation rec {
 
   outputs = [ "out" "lib" "dev" ];
 
-  meta = {
+  meta = llvm_meta // {
-    description = "The LLVM Linker";
+    homepage = "https://lld.llvm.org/";
-    homepage    = "https://lld.llvm.org/";
+    description = "The LLVM linker";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    platforms   = lib.platforms.all;
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
   };
 }

pkgs/development/compilers/llvm/11/lldb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , fetch
 , cmake
 , zlib
@@ -76,11 +76,15 @@ stdenv.mkDerivation (rec {
     ln -s $out/bin/llvm-vscode $out/share/vscode/extensions/llvm-org.lldb-vscode-0.1.0/bin
   '';
 
-  meta = with lib; {
+  meta = llvm_meta // {
+    homepage = "https://lldb.llvm.org/";
     description = "A next-generation high-performance debugger";
-    homepage    = "https://lldb.llvm.org";
+    longDescription = ''
-    license     = licenses.ncsa;
+      LLDB is a next generation, high-performance debugger. It is built as a set
-    platforms   = platforms.all;
+      of reusable components which highly leverage existing libraries in the
+      larger LLVM Project, such as the Clang expression parser and LLVM
+      disassembler.
+    '';
   };
 } // lib.optionalAttrs enableManpages {
   pname = "lldb-manpages";
@@ -104,5 +108,7 @@ stdenv.mkDerivation (rec {
 
   doCheck = false;
 
-  meta.description = "man pages for LLDB ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLDB ${version}";
+  };
 })

pkgs/development/compilers/llvm/11/llvm/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , pkgsBuildBuild
 , fetch
 , cmake
@@ -174,12 +174,23 @@ in stdenv.mkDerivation (rec {
   checkTarget = "check-all";
 
   requiredSystemFeatures = [ "big-parallel" ];
-  meta = {
+  meta = llvm_meta // {
-    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = "https://llvm.org/";
-    homepage    = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+      The LLVM Project is a collection of modular and reusable compiler and
-    platforms   = lib.platforms.all;
+      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";
@@ -201,5 +212,7 @@ in stdenv.mkDerivation (rec {
 
   doCheck = false;
 
-  meta.description = "man pages for LLVM ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
 })

pkgs/development/compilers/llvm/11/openmp.nix

@@ -1,35 +0,0 @@
-{ lib
-, stdenv
-, fetch
-, fetchpatch
-, cmake
-, llvm
-, perl
-, version
-}:
-
-stdenv.mkDerivation rec {
-  pname = "openmp";
-  inherit version;
-
-  src = fetch pname "0bh5cswgpc79awlq8j5i7hp355adaac7s6zaz0zwp6mkflxli1yi";
-
-  patches = [
-    # Fix compilation on aarch64-darwin, remove after the next release.
-    (fetchpatch {
-      url = "https://github.com/llvm/llvm-project/commit/7b5254223acbf2ef9cd278070c5a84ab278d7e5f.patch";
-      sha256 = "sha256-A+9/IVIoazu68FK5H5CiXcOEYe1Hpp4xTx2mIw7m8Es=";
-      stripLen = 1;
-    })
-  ];
-
-  nativeBuildInputs = [ cmake perl ];
-  buildInputs = [ llvm ];
-
-  meta = {
-    description = "Components required to build an executable OpenMP program";
-    homepage    = "https://openmp.llvm.org/";
-    license     = lib.licenses.mit;
-    platforms   = lib.platforms.all;
-  };
-}

pkgs/development/compilers/llvm/11/openmp/default.nix

@@ -0,0 +1,44 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, fetchpatch
+, cmake
+, llvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch pname "0bh5cswgpc79awlq8j5i7hp355adaac7s6zaz0zwp6mkflxli1yi";
+
+  patches = [
+    # Fix compilation on aarch64-darwin, remove after the next release.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/7b5254223acbf2ef9cd278070c5a84ab278d7e5f.patch";
+      sha256 = "sha256-A+9/IVIoazu68FK5H5CiXcOEYe1Hpp4xTx2mIw7m8Es=";
+      stripLen = 1;
+    })
+  ];
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [ llvm ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}

pkgs/development/compilers/llvm/12/compiler-rt/default.nix

@@ -9,7 +9,7 @@ let
 
 in
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
   inherit version;
   src = fetch "compiler-rt" "0d444qihq9jhqnfv003cr704v363va72zl6qaw2algj1c85cva45";
@@ -61,7 +61,6 @@ stdenv.mkDerivation rec {
   ]# ++ lib.optional stdenv.hostPlatform.isMusl ./sanitizers-nongnu.patch
     ++ lib.optional stdenv.hostPlatform.isAarch32 ./armv7l.patch;
 
-
   # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
   # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
   # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd

pkgs/development/compilers/llvm/12/default.nix

@@ -1,4 +1,5 @@
-{ lowPrio, newScope, pkgs, lib, stdenv, cmake, gccForLibs
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
 , libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
@@ -95,7 +96,6 @@ let
 
     lld = callPackage ./lld {
       inherit llvm_meta;
-      libunwind = libraries.libunwind;
     };
 
     lldb = callPackage ./lldb {
@@ -112,7 +112,16 @@ let
     # doesn’t support like LLVM. Probably we should move to some other
     # file.
 
-    bintools = callPackage ./bintools {};
+    bintools-unwrapped = callPackage ./bintools {};
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
 
     lldClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
@@ -141,9 +150,7 @@ let
     lldClangNoLibcxx = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -157,10 +164,7 @@ let
     lldClangNoLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -173,10 +177,7 @@ let
     lldClangNoCompilerRt = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [ ];
       extraBuildCommands = ''
         echo "-nostartfiles" >> $out/nix-support/cc-cflags
@@ -186,9 +187,7 @@ let
     lldClangNoCompilerRtWithLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [ ];
       extraBuildCommands = mkExtraBuildCommands0 cc;
     };
@@ -199,15 +198,19 @@ let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt-libc = callPackage ./compiler-rt ({ inherit llvm_meta; } //
+    compiler-rt-libc = callPackage ./compiler-rt {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc
+               else stdenv;
+    };
 
-    compiler-rt-no-libc = callPackage ./compiler-rt ({ inherit llvm_meta; } //
+    compiler-rt-no-libc = callPackage ./compiler-rt {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt
+               else stdenv;
+    };
 
     # N.B. condition is safe because without useLLVM both are the same.
     compiler-rt = if stdenv.hostPlatform.isAndroid
@@ -218,24 +221,31 @@ let
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libcxx ({ inherit llvm_meta; } //
+    libcxx = callPackage ./libcxx {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
+               else stdenv;
+    };
 
-    libcxxabi = callPackage ./libcxxabi ({ inherit llvm_meta; } //
+    libcxxabi = callPackage ./libcxxabi {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        libunwind = libraries.libunwind;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
-    openmp = callPackage ./openmp { inherit llvm_meta; };
+    libunwind = callPackage ./libunwind {
-
+      inherit llvm_meta;
-    libunwind = callPackage ./libunwind ({ inherit llvm_meta; } //
+      inherit (buildLlvmTools) llvm;
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/12/libcxx/default.nix

@@ -15,7 +15,13 @@ stdenv.mkDerivation {
     mv llvm-* llvm
   '';
 
-  patches = lib.optional stdenv.hostPlatform.isMusl ../../libcxx-0001-musl-hacks.patch;
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
 
   preConfigure = lib.optionalString stdenv.hostPlatform.isMusl ''
     patchShebangs utils/cat_files.py

pkgs/development/compilers/llvm/12/libcxx/gnu-install-dirs.patch

@@ -0,0 +1,100 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 9bf1a02f0908..612cd4aab76c 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -28,6 +28,8 @@ set(LIBCXX_BINARY_INCLUDE_DIR "${LIBCXX_BINARY_DIR}/include/c++build")
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
+   project(libcxx CXX C)
+ 
++  include(GNUInstallDirs)
++
+   set(PACKAGE_NAME libcxx)
+   set(PACKAGE_VERSION 12.0.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -402,7 +404,7 @@ endif ()
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   set(LIBCXX_HEADER_DIR ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
++  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+     string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+@@ -410,11 +412,11 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+   set(LIBCXX_HEADER_DIR  ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
++  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
+   set(LIBCXX_HEADER_DIR  ${CMAKE_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
++  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ endif()
+ 
+ file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
+diff --git a/cmake/Modules/HandleLibCXXABI.cmake b/cmake/Modules/HandleLibCXXABI.cmake
+index 5d2764e870e9..bb1ec5de6ca2 100644
+--- a/cmake/Modules/HandleLibCXXABI.cmake
++++ b/cmake/Modules/HandleLibCXXABI.cmake
+@@ -63,7 +63,7 @@ macro(setup_abi_lib abidefines abishared abistatic abifiles abidirs)
+ 
+         if (LIBCXX_INSTALL_HEADERS)
+           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
+-            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dstdir}
++            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}
+             COMPONENT cxx-headers
+             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+             )
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index 29a317b8ae9a..4747263cfd1b 100644
+--- a/include/CMakeLists.txt
++++ b/include/CMakeLists.txt
+@@ -252,7 +252,7 @@ if (LIBCXX_INSTALL_HEADERS)
+   foreach(file ${files})
+     get_filename_component(dir ${file} DIRECTORY)
+     install(FILES ${file}
+-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dir}
++      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dir}
+       COMPONENT cxx-headers
+       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     )
+@@ -260,7 +260,7 @@ if (LIBCXX_INSTALL_HEADERS)
+ 
+   # Install the generated header as __config.
+   install(FILES ${LIBCXX_BINARY_DIR}/__generated_config
+-    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1
++    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1
+     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     RENAME __config
+     COMPONENT cxx-headers)
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index 9965104cb5b2..9b55dbb1d822 100644
+--- a/src/CMakeLists.txt
++++ b/src/CMakeLists.txt
+@@ -352,21 +352,21 @@ if (LIBCXX_INSTALL_SHARED_LIBRARY)
+   install(TARGETS cxx_shared
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
++    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ if (LIBCXX_INSTALL_STATIC_LIBRARY)
+   install(TARGETS cxx_static
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
++    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
+   install(TARGETS cxx_experimental
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
++    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ # NOTE: This install command must go after the cxx install command otherwise

pkgs/development/compilers/llvm/12/libcxxabi/default.nix

@@ -8,18 +8,7 @@ stdenv.mkDerivation {
 
   src = fetch "libcxxabi" "1cbmzspwjlr8f6sp73pw6ivf4dpg6rpc61by0q1m2zca2k6yif3a";
 
-  nativeBuildInputs = [ cmake python3 ];
+  outputs = [ "out" "dev" ];
-  buildInputs = lib.optional (!stdenv.isDarwin && !stdenv.isFreeBSD && !stdenv.hostPlatform.isWasm) libunwind;
-
-  cmakeFlags = lib.optionals (stdenv.hostPlatform.useLLVM or false) [
-    "-DLLVM_ENABLE_LIBCXX=ON"
-    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
-  ] ++ lib.optionals stdenv.hostPlatform.isWasm [
-    "-DLIBCXXABI_ENABLE_THREADS=OFF"
-    "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
-  ] ++ lib.optionals (!enableShared) [
-    "-DLIBCXXABI_ENABLE_SHARED=OFF"
-  ];
 
   postUnpack = ''
     unpackFile ${libcxx.src}
@@ -34,6 +23,23 @@ stdenv.mkDerivation {
     patch -p1 -d llvm -i ${./wasm.patch}
   '';
 
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake python3 ];
+  buildInputs = lib.optional (!stdenv.isDarwin && !stdenv.isFreeBSD && !stdenv.hostPlatform.isWasm) libunwind;
+
+  cmakeFlags = lib.optionals (stdenv.hostPlatform.useLLVM or false) [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
+  ] ++ lib.optionals stdenv.hostPlatform.isWasm [
+    "-DLIBCXXABI_ENABLE_THREADS=OFF"
+    "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
+  ] ++ lib.optionals (!enableShared) [
+    "-DLIBCXXABI_ENABLE_SHARED=OFF"
+  ];
+
   installPhase = if stdenv.isDarwin
     then ''
       for file in lib/*.dylib; do

pkgs/development/compilers/llvm/12/libcxxabi/gnu-install-dirs.patch

@@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 426c855288fc..a9812a994f53 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -27,6 +27,8 @@ set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
+   project(libcxxabi CXX C)
+ 
++  include(GNUInstallDirs)
++
+   set(PACKAGE_NAME libcxxabi)
+   set(PACKAGE_VERSION 11.0.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -180,17 +182,17 @@ set(CMAKE_MODULE_PATH
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
++  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
++  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
++  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(LIBCXXABI_INSTALL_PREFIX "" CACHE STRING "Define libc++abi destination prefix.")

pkgs/development/compilers/llvm/12/lld/default.nix

@@ -18,6 +18,13 @@ stdenv.mkDerivation rec {
     ./gnu-install-dirs.patch
   ];
 
+  postPatch = ''
+    substituteInPlace MachO/CMakeLists.txt --replace \
+      '(''${LLVM_MAIN_SRC_DIR}/' '('
+    mkdir -p libunwind/include
+    tar -xf "${libunwind.src}" --wildcards -C libunwind/include --strip-components=2 "libunwind-*/include/"
+  '';
+
   nativeBuildInputs = [ cmake ];
   buildInputs = [ libllvm libxml2 ];
 
@@ -29,13 +36,6 @@ stdenv.mkDerivation rec {
 
   outputs = [ "out" "lib" "dev" ];
 
-  postPatch = ''
-    substituteInPlace MachO/CMakeLists.txt --replace \
-      '(''${LLVM_MAIN_SRC_DIR}/' '('
-    mkdir -p libunwind/include
-    tar -xf "${libunwind.src}" --wildcards -C libunwind/include --strip-components=2 "libunwind-*/include/"
-  '';
-
   meta = llvm_meta // {
     homepage = "https://lld.llvm.org/";
     description = "The LLVM linker";
@@ -43,7 +43,7 @@ stdenv.mkDerivation rec {
       LLD is a linker from the LLVM project that is a drop-in replacement for
       system linkers and runs much faster than them. It also provides features
       that are useful for toolchain developers.
-      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS) and
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
       WebAssembly in descending order of completeness. Internally, LLD consists
       of several different linkers.
     '';

pkgs/development/compilers/llvm/12/llvm/default.nix

@@ -205,6 +205,8 @@ in stdenv.mkDerivation (rec {
     make docs-llvm-man
   '';
 
+  propagatedBuildInputs = [];
+
   installPhase = ''
     make -C docs install
   '';

pkgs/development/compilers/llvm/5/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -88,11 +88,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -111,6 +120,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/5/compiler-rt/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
@@ -86,4 +86,19 @@ stdenv.mkDerivation {
     ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/linux/crtendS.o
   '';
 
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/5/default.nix

@@ -16,30 +16,41 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "018b3fiwah8f8br5i26qmzh6sjvzchpn358sn8v079m49f2jldm3";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands = cc: ''
       rsrc="$out/resource-root"
       mkdir "$rsrc"
       ln -s "${cc.lib}/lib/clang/${release_version}/include" "$rsrc"
-      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
       echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
     '';
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
-    libllvm-polly = callPackage ./llvm { enablePolly = true; };
+    libllvm-polly = callPackage ./llvm {
+      inherit llvm_meta;
+      enablePolly = true;
+    };
 
     llvm-polly = tools.libllvm-polly.lib // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
@@ -76,26 +87,38 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt {};
+    compiler-rt = callPackage ./compiler-rt {
+      inherit llvm_meta;
+    };
 
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ {};
+    libcxx = callPackage ./libcxx {
+      inherit llvm_meta;
+    };
 
-    libcxxabi = callPackage ./libc++abi {};
+    libcxxabi = callPackage ./libcxxabi {
+      inherit llvm_meta;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/5/libcxx/default.nix

@@ -1,7 +1,7 @@
-{ lib, stdenv, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version }:
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "1672aaf95fgy4xsfra8pw24f6r93zwzpan1033hkcm8p2glqipvf";
@@ -45,10 +45,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.unix;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }

pkgs/development/compilers/llvm/5/libcxxabi/default.nix

@@ -1,7 +1,7 @@
-{ lib, stdenv, cmake, fetch, libcxx, libunwind, llvm, version }:
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version }:
 
 stdenv.mkDerivation {
-  pname = "libc++abi";
+  pname = "libcxxabi";
   inherit version;
 
   src = fetch "libcxxabi" "12lp799rskr4fc2xr64qn4jfkjnfd8b1aymvsxyn4k9ar7r9pgqv";
@@ -47,11 +47,15 @@ stdenv.mkDerivation {
       ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
     '';
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxxabi.llvm.org/";
-    description = "A new implementation of low level support for a standard C++ library";
+    description = "Provides C++ standard library support";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    maintainers = with lib.maintainers; [ vlstill ];
+      libc++abi is a new implementation of low level support for a standard C++ library.
-    platforms = lib.platforms.unix;
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
   };
 }

pkgs/development/compilers/llvm/5/lld/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , buildLlvmTools
 , fetch
 , cmake
@@ -6,7 +6,7 @@
 , version
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "lld";
   inherit version;
 
@@ -27,11 +27,16 @@ stdenv.mkDerivation {
 
   outputs = [ "out" "lib" "dev" ];
 
-  meta = {
+  meta = llvm_meta // {
-    description = "The LLVM Linker";
+    homepage = "https://lld.llvm.org/";
-    homepage    = "https://lld.llvm.org/";
+    description = "The LLVM linker";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    platforms   = lib.platforms.all;
+      LLD is a linker from the LLVM project that is a drop-in replacement for
-    badPlatforms = [ "x86_64-darwin" ];
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), and Mach-O (macOS)
+      in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
   };
 }

pkgs/development/compilers/llvm/5/lldb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , fetch
 , fetchpatch
 , cmake
@@ -73,10 +73,14 @@ stdenv.mkDerivation rec {
     cp ../docs/lldb.1 $out/share/man/man1/
   '';
 
-  meta = with lib; {
+  meta = llvm_meta // {
+    homepage = "https://lldb.llvm.org/";
     description = "A next-generation high-performance debugger";
-    homepage    = "https://llvm.org/";
+    longDescription = ''
-    license     = licenses.ncsa;
+      LLDB is a next generation, high-performance debugger. It is built as a set
-    platforms   = platforms.all;
+      of reusable components which highly leverage existing libraries in the
+      larger LLVM Project, such as the Clang expression parser and LLVM
+      disassembler.
+    '';
   };
 }

pkgs/development/compilers/llvm/5/llvm/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , pkgsBuildBuild
 , fetch
 , fetchpatch
@@ -173,12 +173,23 @@ stdenv.mkDerivation ({
   checkTarget = "check-all";
 
   requiredSystemFeatures = [ "big-parallel" ];
-  meta = {
+  meta = llvm_meta // {
-    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = "https://llvm.org/";
-    homepage    = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill ];
+      The LLVM Project is a collection of modular and reusable compiler and
-    platforms   = lib.platforms.all;
+      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";
@@ -197,5 +208,7 @@ stdenv.mkDerivation ({
 
   doCheck = false;
 
-  meta.description = "man pages for LLVM ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
 })

pkgs/development/compilers/llvm/5/openmp.nix

@@ -1,25 +0,0 @@
-{ lib
-, stdenv
-, fetch
-, cmake
-, llvm
-, perl
-, version
-}:
-
-stdenv.mkDerivation {
-  pname = "openmp";
-  inherit version;
-
-  src = fetch "openmp" "0p2n52676wlq6y9q99n5pivq6pvvda1p994r69fxj206ahn59jir";
-
-  nativeBuildInputs = [ cmake perl ];
-  buildInputs = [ llvm ];
-
-  meta = {
-    description = "Components required to build an executable OpenMP program";
-    homepage    = "https://openmp.llvm.org/";
-    license     = lib.licenses.mit;
-    platforms   = lib.platforms.all;
-  };
-}

pkgs/development/compilers/llvm/5/openmp/default.nix

@@ -0,0 +1,34 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, cmake
+, llvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch "openmp" "0p2n52676wlq6y9q99n5pivq6pvvda1p994r69fxj206ahn59jir";
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [ llvm ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}

pkgs/development/compilers/llvm/6/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -88,11 +88,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -111,6 +120,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/6/compiler-rt/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
@@ -88,4 +88,19 @@ stdenv.mkDerivation {
     ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/linux/crtendS.o
   '';
 
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/6/default.nix

@@ -16,30 +16,41 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "1w8ml7fyn4vyxmy59n2qm4r1k1kgwgwkaldp6m45fdv4g0kkfbhd";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands = cc: ''
       rsrc="$out/resource-root"
       mkdir "$rsrc"
       ln -s "${cc.lib}/lib/clang/${release_version}/include" "$rsrc"
-      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
       echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
     '';
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
-    libllvm-polly = callPackage ./llvm { enablePolly = true; };
+    libllvm-polly = callPackage ./llvm {
+      inherit llvm_meta;
+      enablePolly = true;
+    };
 
     llvm-polly = tools.libllvm-polly.lib // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
@@ -77,26 +88,38 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt {};
+    compiler-rt = callPackage ./compiler-rt {
+      inherit llvm_meta;
+    };
 
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ {};
+    libcxx = callPackage ./libcxx {
+      inherit llvm_meta;
+    };
 
-    libcxxabi = callPackage ./libc++abi {};
+    libcxxabi = callPackage ./libcxxabi {
+      inherit llvm_meta;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/6/libcxx/default.nix

@@ -1,7 +1,7 @@
-{ lib, stdenv, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version }:
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "0rzw4qvxp6qx4l4h9amrq02gp7hbg8lw4m0sy3k60f50234gnm3n";
@@ -45,10 +45,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.unix;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }

pkgs/development/compilers/llvm/6/libcxxabi/default.nix

@@ -1,7 +1,7 @@
-{ lib, stdenv, cmake, fetch, libcxx, libunwind, llvm, version }:
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version }:
 
 stdenv.mkDerivation {
-  pname = "libc++abi";
+  pname = "libcxxabi";
   inherit version;
 
   src = fetch "libcxxabi" "0prqvdj317qrc8nddaq1hh2ag9algkd9wbkj3y4mr5588k12x7r0";
@@ -47,11 +47,15 @@ stdenv.mkDerivation {
       ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
     '';
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxxabi.llvm.org/";
-    description = "A new implementation of low level support for a standard C++ library";
+    description = "Provides C++ standard library support";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    maintainers = with lib.maintainers; [ vlstill ];
+      libc++abi is a new implementation of low level support for a standard C++ library.
-    platforms = lib.platforms.unix;
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
   };
 }

pkgs/development/compilers/llvm/6/lld/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , buildLlvmTools
 , fetch
 , cmake
@@ -7,11 +7,11 @@
 , version
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "lld";
   inherit version;
 
-  src = fetch "lld" "04afcfq2h7ysyqxxhyhb7ig4p0vdw7mi63kh8mffl74j0rc781p7";
+  src = fetch pname "04afcfq2h7ysyqxxhyhb7ig4p0vdw7mi63kh8mffl74j0rc781p7";
 
   patches = [
     ./gnu-install-dirs.patch
@@ -28,10 +28,16 @@ stdenv.mkDerivation {
 
   outputs = [ "out" "lib" "dev" ];
 
-  meta = {
+  meta = llvm_meta // {
-    description = "The LLVM Linker";
+    homepage = "https://lld.llvm.org/";
-    homepage    = "https://lld.llvm.org/";
+    description = "The LLVM linker";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    platforms   = lib.platforms.all;
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), and Mach-O (macOS)
+      in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
   };
 }

pkgs/development/compilers/llvm/6/lldb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , fetch
 , fetchpatch
 , cmake
@@ -73,10 +73,14 @@ stdenv.mkDerivation rec {
     cp ../docs/lldb.1 $out/share/man/man1/
   '';
 
-  meta = with lib; {
+  meta = llvm_meta // {
+    homepage = "https://lldb.llvm.org/";
     description = "A next-generation high-performance debugger";
-    homepage    = "https://llvm.org/";
+    longDescription = ''
-    license     = licenses.ncsa;
+      LLDB is a next generation, high-performance debugger. It is built as a set
-    platforms   = platforms.all;
+      of reusable components which highly leverage existing libraries in the
+      larger LLVM Project, such as the Clang expression parser and LLVM
+      disassembler.
+    '';
   };
 }

pkgs/development/compilers/llvm/6/llvm/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , pkgsBuildBuild
 , fetch
 , cmake
@@ -167,12 +167,23 @@ stdenv.mkDerivation ({
   checkTarget = "check-all";
 
   requiredSystemFeatures = [ "big-parallel" ];
-  meta = {
+  meta = llvm_meta // {
-    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = "https://llvm.org/";
-    homepage    = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill ];
+      The LLVM Project is a collection of modular and reusable compiler and
-    platforms   = lib.platforms.all;
+      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";
@@ -191,5 +202,7 @@ stdenv.mkDerivation ({
 
   doCheck = false;
 
-  meta.description = "man pages for LLVM ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
 })

pkgs/development/compilers/llvm/6/openmp.nix

@@ -1,25 +0,0 @@
-{ lib
-, stdenv
-, fetch
-, cmake
-, llvm
-, perl
-, version
-}:
-
-stdenv.mkDerivation {
-  pname = "openmp";
-  inherit version;
-
-  src = fetch "openmp" "0nhwfba9c351r16zgyjyfwdayr98nairky3c2f0b2lc360mwmbv6";
-
-  nativeBuildInputs = [ cmake perl ];
-  buildInputs = [ llvm ];
-
-  meta = {
-    description = "Components required to build an executable OpenMP program";
-    homepage    = "https://openmp.llvm.org/";
-    license     = lib.licenses.mit;
-    platforms   = lib.platforms.all;
-  };
-}

pkgs/development/compilers/llvm/6/openmp/default.nix

@@ -0,0 +1,34 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, cmake
+, llvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch "openmp" "0nhwfba9c351r16zgyjyfwdayr98nairky3c2f0b2lc360mwmbv6";
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [ llvm ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}

pkgs/development/compilers/llvm/7/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -100,11 +100,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -123,6 +132,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/7/compiler-rt/default.nix

@@ -1,15 +1,16 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
   useLLVM = stdenv.hostPlatform.useLLVM or false;
   bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
   inherit (stdenv.hostPlatform) isMusl;
 
 in
 
 stdenv.mkDerivation {
-  pname = "compiler-rt";
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
   inherit version;
   src = fetch "compiler-rt" "1n48p8gjarihkws0i2bay5w9bdwyxyxxbpwyng7ba58jb30dlyq5";
 
@@ -29,14 +30,15 @@ stdenv.mkDerivation {
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ lib.optionals (useLLVM || bareMetal) [
+  ] ++ lib.optionals ((useLLVM || bareMetal) && !haveLibc) [
     "-DCMAKE_C_COMPILER_WORKS=ON"
     "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
     "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM && !haveLibc) [
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
   ] ++ lib.optionals (useLLVM) [
     "-DCOMPILER_RT_BUILD_BUILTINS=ON"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
   ] ++ lib.optionals (bareMetal) [
@@ -83,10 +85,25 @@ stdenv.mkDerivation {
   postInstall = lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
     ln -s "$out/lib"/*/* "$out/lib"
   '' + lib.optionalString (useLLVM) ''
-    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/linux/crtbegin.o
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
-    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/linux/crtend.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
-    ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/linux/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
-    ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/linux/crtendS.o
+    ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
   '';
 
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/7/default.nix

@@ -1,4 +1,5 @@
-{ lowPrio, newScope, pkgs, lib, stdenv, cmake, gccForLibs
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
 , libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
@@ -16,6 +17,12 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "0lb4kdh7j2fhfz8kd6iv5df7m3pikiryk1vvwsf87spc90n09q0w";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands0 = cc: ''
@@ -30,23 +37,29 @@ let
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
-    libllvm-polly = callPackage ./llvm { enablePolly = true; };
+    libllvm-polly = callPackage ./llvm {
+      inherit llvm_meta;
+      enablePolly = true;
+    };
 
     llvm-polly = tools.libllvm-polly.lib // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
 
     clang-polly-unwrapped = callPackage ./clang {
+      inherit llvm_meta;
       inherit clang-tools-extra_src;
       libllvm = tools.libllvm-polly;
       enablePolly = true;
@@ -84,9 +97,13 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
 
     # Below, is the LLVM bootstrapping logic. It handles building a
     # fully LLVM toolchain from scratch. No GCC toolchain should be
@@ -95,7 +112,16 @@ let
     # doesn’t support like LLVM. Probably we should move to some other
     # file.
 
-    bintools = callPackage ./bintools.nix {};
+    bintools-unwrapped = callPackage ./bintools {};
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
 
     lldClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
@@ -106,12 +132,16 @@ let
       extraPackages = [
         targetLlvmLibraries.libcxxabi
         targetLlvmLibraries.compiler-rt
+      ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
+        targetLlvmLibraries.libunwind
       ];
       extraBuildCommands = ''
         echo "-rtlib=compiler-rt -Wno-unused-command-line-argument" >> $out/nix-support/cc-cflags
         echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
       '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
         echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (stdenv.targetPlatform.isAndroid && stdenv.targetPlatform.useLLVM) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
       '' + lib.optionalString stdenv.targetPlatform.isWasm ''
         echo "-fno-exceptions" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands cc;
@@ -120,9 +150,7 @@ let
     lldClangNoLibcxx = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -136,10 +164,7 @@ let
     lldClangNoLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -152,50 +177,75 @@ let
     lldClangNoCompilerRt = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [ ];
       extraBuildCommands = ''
         echo "-nostartfiles" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands0 cc;
     };
 
+    lldClangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      inherit (tools) bintools;
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt {
+    compiler-rt-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
       stdenv = if stdenv.hostPlatform.useLLVM or false
                then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt
                else stdenv;
     };
 
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
+
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ ({} //
+    libcxx = callPackage ./libcxx {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
+               else stdenv;
+    };
 
-    libcxxabi = callPackage ./libc++abi ({} //
+    libcxxabi = callPackage ./libcxxabi {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        libunwind = libraries.libunwind;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
-    libunwind = callPackage ./libunwind ({
+    libunwind = callPackage ./libunwind {
+      inherit llvm_meta;
       inherit (buildLlvmTools) llvm;
-    } // lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-    });
+               else stdenv;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/7/libcxx/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "0kmhcapm2cjwalyiqasj9dmqbw59mcwdl8fgl951wg7ax84b8hj4";
@@ -17,7 +17,9 @@ stdenv.mkDerivation {
 
   patches = [
     ./gnu-install-dirs.patch
-  ] ++ lib.optional stdenv.hostPlatform.isMusl ../../libcxx-0001-musl-hacks.patch;
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
 
   prePatch = ''
     substituteInPlace lib/CMakeLists.txt --replace "/usr/lib/libc++" "\''${LIBCXX_LIBCXXABI_LIB_PATH}/libc++"
@@ -34,7 +36,7 @@ stdenv.mkDerivation {
     ++ lib.optional stdenv.hostPlatform.isMusl python3
     ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
 
-  buildInputs = [ libcxxabi ] ;
+  buildInputs = [ libcxxabi ];
 
   cmakeFlags = [
     "-DLIBCXX_LIBCXXABI_LIB_PATH=${libcxxabi}/lib"
@@ -48,10 +50,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.unix;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }

pkgs/development/compilers/llvm/7/libcxxabi/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, cmake, fetch, libcxx, libunwind, llvm, version
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version
 , standalone ? stdenv.hostPlatform.useLLVM or false
 , withLibunwind ? !stdenv.isDarwin && !stdenv.isFreeBSD && !stdenv.hostPlatform.isWasm
   # on musl the shared objects don't build
@@ -6,7 +6,7 @@
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++abi";
+  pname = "libcxxabi";
   inherit version;
 
   src = fetch "libcxxabi" "1zcqxsdjhawgz1cvpk07y3jl6fg9p3ay4nl69zsirqb2ghgyhhb2";
@@ -58,11 +58,15 @@ stdenv.mkDerivation {
       ${lib.optionalString enableShared "ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1"}
     '';
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxxabi.llvm.org/";
-    description = "A new implementation of low level support for a standard C++ library";
+    description = "Provides C++ standard library support";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    maintainers = with lib.maintainers; [ vlstill ];
+      libc++abi is a new implementation of low level support for a standard C++ library.
-    platforms = lib.platforms.unix;
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
   };
 }

pkgs/development/compilers/llvm/7/libunwind/default.nix

@@ -1,12 +1,17 @@
-{ lib, stdenv, version, fetch, fetchpatch, cmake, llvm, libcxx
+{ lib, stdenv, llvm_meta, version, fetch, fetchpatch, cmake, llvm
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libunwind";
   inherit version;
 
-  src = fetch "libunwind" "035dsxs10nyiqd00q07yycvmkjl01yz4jdlrjvmch8klxg4pyjhp";
+  src = fetch pname "035dsxs10nyiqd00q07yycvmkjl01yz4jdlrjvmch8klxg4pyjhp";
+
+  postUnpack = ''
+    unpackFile ${llvm.src}
+    cmakeFlagsArray=($cmakeFlagsArray -DLLVM_PATH=$PWD/$(ls -d llvm-*))
+  '';
 
   patches = [
     ./gnu-install-dirs.patch
@@ -24,12 +29,25 @@ stdenv.mkDerivation {
     })
   ];
 
-  nativeBuildInputs = [ cmake llvm.dev ];
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [ cmake ];
 
   cmakeFlags = lib.optionals (!enableShared) [
     "-DLIBUNWIND_ENABLE_SHARED=OFF"
   ] ++ lib.optionals (stdenv.hostPlatform.useLLVM or false) [
-    "-DLIBUNWIND_HAS_NOSTDINCXX_FLAG=ON"
     "-DLLVM_ENABLE_LIBCXX=ON"
   ];
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
 }

pkgs/development/compilers/llvm/7/lld/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , buildLlvmTools
 , fetch
 , cmake
@@ -7,11 +7,11 @@
 , version
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "lld";
   inherit version;
 
-  src = fetch "lld" "0rsqb7zcnij5r5ipfhr129j7skr5n9pyr388kjpqwh091952f3x1";
+  src = fetch pname "0rsqb7zcnij5r5ipfhr129j7skr5n9pyr388kjpqwh091952f3x1";
 
   patches = [
     ./gnu-install-dirs.patch
@@ -28,10 +28,16 @@ stdenv.mkDerivation {
 
   outputs = [ "out" "lib" "dev" ];
 
-  meta = {
+  meta = llvm_meta // {
-    description = "The LLVM Linker";
+    homepage = "https://lld.llvm.org/";
-    homepage    = "https://lld.llvm.org/";
+    description = "The LLVM linker";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    platforms   = lib.platforms.all;
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), and Mach-O (macOS)
+      in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
   };
 }

pkgs/development/compilers/llvm/7/lldb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , fetch
 , cmake
 , zlib
@@ -76,10 +76,14 @@ stdenv.mkDerivation rec {
     cp ../docs/lldb.1 $out/share/man/man1/
   '';
 
-  meta = with lib; {
+  meta = llvm_meta // {
+    homepage = "https://lldb.llvm.org/";
     description = "A next-generation high-performance debugger";
-    homepage    = "https://llvm.org/";
+    longDescription = ''
-    license     = licenses.ncsa;
+      LLDB is a next generation, high-performance debugger. It is built as a set
-    platforms   = platforms.all;
+      of reusable components which highly leverage existing libraries in the
+      larger LLVM Project, such as the Clang expression parser and LLVM
+      disassembler.
+    '';
   };
 }

pkgs/development/compilers/llvm/7/llvm/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , pkgsBuildBuild
 , fetch
 , fetchpatch
@@ -184,12 +184,23 @@ in stdenv.mkDerivation ({
   checkTarget = "check-all";
 
   requiredSystemFeatures = [ "big-parallel" ];
-  meta = {
+  meta = llvm_meta // {
-    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = "https://llvm.org/";
-    homepage    = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill ];
+      The LLVM Project is a collection of modular and reusable compiler and
-    platforms   = lib.platforms.all;
+      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";
@@ -211,5 +222,7 @@ in stdenv.mkDerivation ({
 
   doCheck = false;
 
-  meta.description = "man pages for LLVM ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
 })

pkgs/development/compilers/llvm/7/openmp.nix

@@ -1,25 +0,0 @@
-{ lib
-, stdenv
-, fetch
-, cmake
-, llvm
-, perl
-, version
-}:
-
-stdenv.mkDerivation {
-  pname = "openmp";
-  inherit version;
-
-  src = fetch "openmp" "1dg53wzsci2kra8lh1y0chh60h2l8h1by93br5spzvzlxshkmrqy";
-
-  nativeBuildInputs = [ cmake perl ];
-  buildInputs = [ llvm ];
-
-  meta = {
-    description = "Components required to build an executable OpenMP program";
-    homepage    = "https://openmp.llvm.org/";
-    license     = lib.licenses.mit;
-    platforms   = lib.platforms.all;
-  };
-}

pkgs/development/compilers/llvm/7/openmp/default.nix

@@ -0,0 +1,34 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, cmake
+, llvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch "openmp" "1dg53wzsci2kra8lh1y0chh60h2l8h1by93br5spzvzlxshkmrqy";
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [ llvm ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}

pkgs/development/compilers/llvm/8/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -107,11 +107,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -130,6 +139,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/8/compiler-rt/default.nix

@@ -1,15 +1,16 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
   useLLVM = stdenv.hostPlatform.useLLVM or false;
   bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
   inherit (stdenv.hostPlatform) isMusl;
 
 in
 
 stdenv.mkDerivation {
-  pname = "compiler-rt";
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
   inherit version;
   src = fetch "compiler-rt" "0dqqf8f930l8gag4d9qjgn1n0pj0nbv2anviqqhdi1rkhas8z0hi";
 
@@ -29,14 +30,15 @@ stdenv.mkDerivation {
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ lib.optionals (useLLVM || bareMetal) [
+  ] ++ lib.optionals ((useLLVM || bareMetal) && !haveLibc) [
     "-DCMAKE_C_COMPILER_WORKS=ON"
     "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
     "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM && !haveLibc) [
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
   ] ++ lib.optionals (useLLVM) [
     "-DCOMPILER_RT_BUILD_BUILTINS=ON"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
   ] ++ lib.optionals (bareMetal) [
@@ -89,4 +91,19 @@ stdenv.mkDerivation {
     ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
   '';
 
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/8/default.nix

@@ -1,4 +1,5 @@
-{ lowPrio, newScope, pkgs, lib, stdenv, cmake, gccForLibs
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
 , libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
@@ -16,6 +17,12 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "1qf3097bc5ia8p6cpmbx985rjr3yaah5s8fc0nv7pw742yv7jw8q";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands0 = cc: ''
@@ -30,23 +37,29 @@ let
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
-    libllvm-polly = callPackage ./llvm { enablePolly = true; };
+    libllvm-polly = callPackage ./llvm {
+      inherit llvm_meta;
+      enablePolly = true;
+    };
 
     llvm-polly = tools.libllvm-polly.lib // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
 
     clang-polly-unwrapped = callPackage ./clang {
+      inherit llvm_meta;
       inherit clang-tools-extra_src;
       libllvm = tools.libllvm-polly;
       enablePolly = true;
@@ -85,9 +98,13 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
 
     # Below, is the LLVM bootstrapping logic. It handles building a
     # fully LLVM toolchain from scratch. No GCC toolchain should be
@@ -96,7 +113,16 @@ let
     # doesn’t support like LLVM. Probably we should move to some other
     # file.
 
-    bintools = callPackage ./bintools.nix {};
+    bintools-unwrapped = callPackage ./bintools {};
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
 
     lldClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
@@ -115,6 +141,8 @@ let
         echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
       '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
         echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (stdenv.targetPlatform.isAndroid && stdenv.targetPlatform.useLLVM) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
       '' + lib.optionalString stdenv.targetPlatform.isWasm ''
         echo "-fno-exceptions" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands cc;
@@ -123,9 +151,7 @@ let
     lldClangNoLibcxx = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -139,10 +165,7 @@ let
     lldClangNoLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -155,49 +178,74 @@ let
     lldClangNoCompilerRt = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [ ];
       extraBuildCommands = ''
         echo "-nostartfiles" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands0 cc;
     };
 
+    lldClangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      inherit (tools) bintools;
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt ({} //
+    compiler-rt-libc = callPackage ./compiler-rt {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
 
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ ({} //
+    libcxx = callPackage ./libcxx {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
+               else stdenv;
+    };
 
-    libcxxabi = callPackage ./libc++abi ({} //
+    libcxxabi = callPackage ./libcxxabi {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        libunwind = libraries.libunwind;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    libunwind = callPackage ./libunwind {
-
+      inherit llvm_meta;
-    libunwind = callPackage ./libunwind ({} //
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+               else stdenv;
-      }));
+    };
 
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/8/libcxx/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "0y4vc9z36c1zlq15cnibdzxnc1xi5glbc6klnm8a41q3db4541kz";
@@ -17,7 +17,9 @@ stdenv.mkDerivation {
 
   patches = [
     ./gnu-install-dirs.patch
-  ] ++ lib.optional stdenv.hostPlatform.isMusl ../../libcxx-0001-musl-hacks.patch;
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
 
   prePatch = ''
     substituteInPlace lib/CMakeLists.txt --replace "/usr/lib/libc++" "\''${LIBCXX_LIBCXXABI_LIB_PATH}/libc++"
@@ -51,10 +53,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.all;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }

pkgs/development/compilers/llvm/8/libcxxabi/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, cmake, fetch, libcxx, libunwind, llvm, version
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++abi";
+  pname = "libcxxabi";
   inherit version;
 
   src = fetch "libcxxabi" "1vznz8n1z1h8af0ga451m98lc2hjnv4fyzl71napsvjhvk4g6nxp";
@@ -63,11 +63,15 @@ stdenv.mkDerivation {
       ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
     '';
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxxabi.llvm.org/";
-    description = "A new implementation of low level support for a standard C++ library";
+    description = "Provides C++ standard library support";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    maintainers = with lib.maintainers; [ vlstill ];
+      libc++abi is a new implementation of low level support for a standard C++ library.
-    platforms = lib.platforms.all;
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
   };
 }

pkgs/development/compilers/llvm/8/libunwind/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, version, fetch, cmake, fetchpatch
+{ lib, stdenv, llvm_meta, version, fetch, cmake, fetchpatch
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
@@ -25,4 +25,16 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ cmake ];
 
   cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
 }

pkgs/development/compilers/llvm/8/lld/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , buildLlvmTools
 , fetch
 , cmake
@@ -7,11 +7,11 @@
 , version
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "lld";
   inherit version;
 
-  src = fetch "lld" "121xhxrlvwy3k5nf6p1wv31whxlb635ssfkci8z93mwv4ja1xflz";
+  src = fetch pname "121xhxrlvwy3k5nf6p1wv31whxlb635ssfkci8z93mwv4ja1xflz";
 
   patches = [
     ./gnu-install-dirs.patch
@@ -28,10 +28,16 @@ stdenv.mkDerivation {
 
   outputs = [ "out" "lib" "dev" ];
 
-  meta = {
+  meta = llvm_meta // {
-    description = "The LLVM Linker";
+    homepage = "https://lld.llvm.org/";
-    homepage    = "https://lld.llvm.org/";
+    description = "The LLVM linker";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    platforms   = lib.platforms.all;
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
   };
 }

pkgs/development/compilers/llvm/8/lldb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , fetch
 , cmake
 , zlib
@@ -70,10 +70,14 @@ stdenv.mkDerivation rec {
     ln -s $out/bin/llvm-vscode $out/share/vscode/extensions/llvm-org.lldb-vscode-0.1.0/bin
   '';
 
-  meta = with lib; {
+  meta = llvm_meta // {
+    homepage = "https://lldb.llvm.org/";
     description = "A next-generation high-performance debugger";
-    homepage    = "https://llvm.org/";
+    longDescription = ''
-    license     = licenses.ncsa;
+      LLDB is a next generation, high-performance debugger. It is built as a set
-    platforms   = platforms.all;
+      of reusable components which highly leverage existing libraries in the
+      larger LLVM Project, such as the Clang expression parser and LLVM
+      disassembler.
+    '';
   };
 }

pkgs/development/compilers/llvm/8/llvm/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv
+{ lib, stdenv, llvm_meta
 , pkgsBuildBuild
 , fetch
 , fetchpatch
@@ -168,12 +168,23 @@ in stdenv.mkDerivation ({
   checkTarget = "check-all";
 
   requiredSystemFeatures = [ "big-parallel" ];
-  meta = {
+  meta = llvm_meta // {
-    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = "https://llvm.org/";
-    homepage    = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
-    license     = lib.licenses.ncsa;
+    longDescription = ''
-    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill ];
+      The LLVM Project is a collection of modular and reusable compiler and
-    platforms   = lib.platforms.all;
+      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";
@@ -195,5 +206,7 @@ in stdenv.mkDerivation ({
 
   doCheck = false;
 
-  meta.description = "man pages for LLVM ${version}";
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
 })

pkgs/development/compilers/llvm/8/openmp.nix

@@ -1,25 +0,0 @@
-{ lib
-, stdenv
-, fetch
-, cmake
-, llvm
-, perl
-, version
-}:
-
-stdenv.mkDerivation {
-  pname = "openmp";
-  inherit version;
-
-  src = fetch "openmp" "0b3jlxhqbpyd1nqkpxjfggm5d9va5qpyf7d4i5y7n4a1mlydv19y";
-
-  nativeBuildInputs = [ cmake perl ];
-  buildInputs = [ llvm ];
-
-  meta = {
-    description = "Components required to build an executable OpenMP program";
-    homepage    = "https://openmp.llvm.org/";
-    license     = lib.licenses.mit;
-    platforms   = lib.platforms.all;
-  };
-}

pkgs/development/compilers/llvm/8/openmp/default.nix

@@ -0,0 +1,34 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, cmake
+, llvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch "openmp" "0b3jlxhqbpyd1nqkpxjfggm5d9va5qpyf7d4i5y7n4a1mlydv19y";
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [ llvm ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}

pkgs/development/compilers/llvm/9/clang/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+{ lib, stdenv, llvm_meta, fetch, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
 , buildLlvmTools
 , fixDarwinDylibNames
 , enableManpages ? false
@@ -102,11 +102,20 @@ let
       inherit libllvm;
     };
 
-    meta = {
+    meta = llvm_meta // {
-      description = "A c, c++, objective-c, and objective-c++ frontend for the llvm compiler";
+      homepage = "https://clang.llvm.org/";
-      homepage    = "https://llvm.org/";
+      description = "A C language family frontend for LLVM";
-      license     = lib.licenses.ncsa;
+      longDescription = ''
-      platforms   = lib.platforms.all;
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
     };
   } // lib.optionalAttrs enableManpages {
     pname = "clang-manpages";
@@ -125,6 +134,8 @@ let
 
     doCheck = false;
 
-    meta.description = "man page for Clang ${version}";
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
   });
 in self

pkgs/development/compilers/llvm/9/compiler-rt/default.nix

@@ -1,17 +1,18 @@
-{ lib, stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, llvm, libcxxabi }:
 
 let
 
   useLLVM = stdenv.hostPlatform.useLLVM or false;
   bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
   inherit (stdenv.hostPlatform) isMusl;
 
 in
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
-  pname = "compiler-rt";
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
   inherit version;
-  src = fetch pname "0xwh79g3zggdabxgnd0bphry75asm1qz7mv3hcqihqwqr6aspgy2";
+  src = fetch "compiler-rt" "0xwh79g3zggdabxgnd0bphry75asm1qz7mv3hcqihqwqr6aspgy2";
 
   nativeBuildInputs = [ cmake python3 llvm.dev ];
   buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
@@ -29,14 +30,15 @@ stdenv.mkDerivation rec {
     "-DCOMPILER_RT_BUILD_XRAY=OFF"
     "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
     "-DCOMPILER_RT_BUILD_PROFILE=OFF"
-  ] ++ lib.optionals (useLLVM || bareMetal) [
+  ] ++ lib.optionals ((useLLVM || bareMetal) && !haveLibc) [
     "-DCMAKE_C_COMPILER_WORKS=ON"
     "-DCMAKE_CXX_COMPILER_WORKS=ON"
     "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
     "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM && !haveLibc) [
+    "-DCMAKE_C_FLAGS=-nodefaultlibs"
   ] ++ lib.optionals (useLLVM) [
     "-DCOMPILER_RT_BUILD_BUILTINS=ON"
-    "-DCMAKE_C_FLAGS=-nodefaultlibs"
     #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
     "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
   ] ++ lib.optionals (bareMetal) [
@@ -87,4 +89,20 @@ stdenv.mkDerivation rec {
     ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
     ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
   '';
+
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
 }

pkgs/development/compilers/llvm/9/default.nix

@@ -1,4 +1,5 @@
-{ lowPrio, newScope, pkgs, lib, stdenv, cmake, gccForLibs
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
 , libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
@@ -16,6 +17,12 @@ let
 
   clang-tools-extra_src = fetch "clang-tools-extra" "01vgzd4k1q93nfs8gyl83mjlc4x0qsgfqw32lacbjzdxg0mdfvxj";
 
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = with lib.maintainers; [ lovek323 raskin dtzWill primeos ];
+    platforms   = lib.platforms.all;
+  };
+
   tools = lib.makeExtensible (tools: let
     callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
     mkExtraBuildCommands0 = cc: ''
@@ -30,23 +37,29 @@ let
 
   in {
 
-    libllvm = callPackage ./llvm { };
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
 
     # `llvm` historically had the binaries.  When choosing an output explicitly,
     # we need to reintroduce `outputUnspecified` to get the expected behavior e.g. of lib.get*
     llvm = tools.libllvm.out // { outputUnspecified = true; };
 
-    libllvm-polly = callPackage ./llvm { enablePolly = true; };
+    libllvm-polly = callPackage ./llvm {
+      inherit llvm_meta;
+      enablePolly = true;
+    };
 
     llvm-polly = tools.libllvm-polly.lib // { outputUnspecified = true; };
 
     libclang = callPackage ./clang {
-      inherit clang-tools-extra_src;
+      inherit clang-tools-extra_src llvm_meta;
     };
 
     clang-unwrapped = tools.libclang.out // { outputUnspecified = true; };
 
     clang-polly-unwrapped = callPackage ./clang {
+      inherit llvm_meta;
       inherit clang-tools-extra_src;
       libllvm = tools.libllvm-polly;
       enablePolly = true;
@@ -85,9 +98,13 @@ let
       extraBuildCommands = mkExtraBuildCommands cc;
     };
 
-    lld = callPackage ./lld {};
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
 
-    lldb = callPackage ./lldb {};
+    lldb = callPackage ./lldb {
+      inherit llvm_meta;
+    };
 
     # Below, is the LLVM bootstrapping logic. It handles building a
     # fully LLVM toolchain from scratch. No GCC toolchain should be
@@ -96,7 +113,16 @@ let
     # doesn’t support like LLVM. Probably we should move to some other
     # file.
 
-    bintools = callPackage ./bintools.nix {};
+    bintools-unwrapped = callPackage ./bintools {};
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
 
     lldClang = wrapCCWith rec {
       cc = tools.clang-unwrapped;
@@ -115,6 +141,8 @@ let
         echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
       '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
         echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (stdenv.targetPlatform.isAndroid && stdenv.targetPlatform.useLLVM) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
       '' + lib.optionalString stdenv.targetPlatform.isWasm ''
         echo "-fno-exceptions" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands cc;
@@ -123,9 +151,7 @@ let
     lldClangNoLibcxx = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      inherit (tools) bintools;
-        inherit (tools) bintools;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -139,10 +165,7 @@ let
     lldClangNoLibc = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [
         targetLlvmLibraries.compiler-rt
       ];
@@ -155,49 +178,74 @@ let
     lldClangNoCompilerRt = wrapCCWith rec {
       cc = tools.clang-unwrapped;
       libcxx = null;
-      bintools = wrapBintoolsWith {
+      bintools = tools.bintoolsNoLibc;
-        inherit (tools) bintools;
-        libc = null;
-      };
       extraPackages = [ ];
       extraBuildCommands = ''
         echo "-nostartfiles" >> $out/nix-support/cc-cflags
       '' + mkExtraBuildCommands0 cc;
     };
 
+    lldClangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      inherit (tools) bintools;
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
   });
 
   libraries = lib.makeExtensible (libraries: let
     callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
   in {
 
-    compiler-rt = callPackage ./compiler-rt ({} //
+    compiler-rt-libc = callPackage ./compiler-rt {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.lldClangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
 
     stdenv = overrideCC stdenv buildLlvmTools.clang;
 
     libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
 
-    libcxx = callPackage ./libc++ ({} //
+    libcxx = callPackage ./libcxx {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      }));
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
+               else stdenv;
+    };
 
-    libcxxabi = callPackage ./libc++abi ({} //
+    libcxxabi = callPackage ./libcxxabi {
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+      inherit llvm_meta;
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-        libunwind = libraries.libunwind;
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-      }));
+               else stdenv;
+    };
 
-    openmp = callPackage ./openmp.nix {};
+    libunwind = callPackage ./libunwind {
-
+      inherit llvm_meta;
-    libunwind = callPackage ./libunwind ({} //
+      stdenv = if stdenv.hostPlatform.useLLVM or false
-      (lib.optionalAttrs (stdenv.hostPlatform.useLLVM or false) {
+               then overrideCC stdenv buildLlvmTools.lldClangNoLibcxx
-        stdenv = overrideCC stdenv buildLlvmTools.lldClangNoLibcxx;
+               else stdenv;
-      }));
+    };
 
+    openmp = callPackage ./openmp {
+      inherit llvm_meta;
+    };
   });
 
 in { inherit tools libraries; } // libraries // tools

pkgs/development/compilers/llvm/9/libcxx/default.nix

@@ -1,9 +1,9 @@
-{ lib, stdenv, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, libcxxabi, fixDarwinDylibNames, version
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
 
 stdenv.mkDerivation {
-  pname = "libc++";
+  pname = "libcxx";
   inherit version;
 
   src = fetch "libcxx" "0d2bj5i6mk4caq7skd5nsdmz8c2m5w5anximl5wz3x32p08zz089";
@@ -17,7 +17,9 @@ stdenv.mkDerivation {
 
   patches = [
     ./gnu-install-dirs.patch
-  ] ++ lib.optional stdenv.hostPlatform.isMusl ../../libcxx-0001-musl-hacks.patch;
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
 
   preConfigure = ''
     # Get headers from the cxxabi source so we can see private headers not installed by the cxxabi package
@@ -47,10 +49,15 @@ stdenv.mkDerivation {
     isLLVM = true;
   };
 
-  meta = {
+  meta = llvm_meta // {
     homepage = "https://libcxx.llvm.org/";
-    description = "A new implementation of the C++ standard library, targeting C++11";
+    description = "C++ standard library";
-    license = with lib.licenses; [ ncsa mit ];
+    longDescription = ''
-    platforms = lib.platforms.all;
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
   };
 }