llvm-4/clang-4: Build and install man pages

pkgs/development/compilers/llvm/4/clang/default.nix

@@ -13,10 +13,15 @@ let
       mv clang-tools-extra-* $sourceRoot/tools/extra
     '';
 
-    buildInputs = [ cmake libedit libxml2 llvm python ];
+    buildInputs = [ cmake libedit libxml2 llvm python python.pkgs.sphinx ];
 
     cmakeFlags = [
       "-DCMAKE_CXX_FLAGS=-std=c++11"
+      "-DCLANG_INCLUDE_DOCS=ON"
+      "-DLLVM_ENABLE_SPHINX=ON"
+      "-DSPHINX_OUTPUT_MAN=ON"
+      "-DSPHINX_OUTPUT_HTML=OFF"
+      "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
     ] ++
     # Maybe with compiler-rt this won't be needed?
     (stdenv.lib.optional stdenv.isLinux "-DGCC_INSTALL_PREFIX=${gcc}") ++
@@ -24,12 +29,19 @@ let
 
     patches = [ ./purity.patch ];
 
+    postBuild = ''
+      cmake --build . --target docs-clang-man
+    '';
+
     postPatch = ''
       sed -i -e 's/Args.hasArg(options::OPT_nostdlibinc)/true/' lib/Driver/Tools.cpp
       sed -i -e 's/DriverArgs.hasArg(options::OPT_nostdlibinc)/true/' lib/Driver/ToolChains.cpp
+
+      # Patch for standalone doc building
+      sed -i '1s,^,find_package(Sphinx REQUIRED)\n,' docs/CMakeLists.txt
     '';
 
-    outputs = [ "out" "python" ];
+    outputs = [ "out" "man" "python" ];
 
     # Clang expects to find LLVMgold in its own prefix
     # Clang expects to find sanitizer libraries in its own prefix
@@ -46,6 +58,12 @@ let
       mv $out/share/clang/*.py $python/share/clang
 
       rm $out/bin/c-index-test
+
+      # Manually install clang manpage
+      cp docs/man/*.1 $out/share/man/man1/
+
+      # Move it and other man pages to 'man' output
+      moveToOutput "share/man" "$man"
     '';
 
     enableParallelBuilding = true;

pkgs/development/compilers/llvm/4/llvm.nix

@@ -38,9 +38,9 @@ in stdenv.mkDerivation rec {
     mv compiler-rt-* $sourceRoot/projects/compiler-rt
   '';
 
-  outputs = [ "out" ] ++ stdenv.lib.optional enableSharedLibraries "lib";
+  outputs = [ "out" "man" ] ++ stdenv.lib.optional enableSharedLibraries "lib";
 
-  buildInputs = [ perl groff cmake libxml2 python libffi ]
+  buildInputs = [ perl groff cmake libxml2 python libffi python.pkgs.sphinx ]
     ++ stdenv.lib.optionals stdenv.isDarwin [ libcxxabi ];
 
   propagatedBuildInputs = [ ncurses zlib ];
@@ -80,6 +80,11 @@ in stdenv.mkDerivation rec {
     "-DLLVM_ENABLE_FFI=ON"
     "-DLLVM_ENABLE_RTTI=ON"
     "-DCOMPILER_RT_INCLUDE_TESTS=OFF" # FIXME: requires clang source code
+    "-DLLVM_BUILD_DOCS=ON"
+    "-DLLVM_ENABLE_SPHINX=ON"
+    "-DSPHINX_OUTPUT_MAN=ON"
+    "-DSPHINX_OUTPUT_HTML=OFF"
+    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
   ] ++ stdenv.lib.optional enableSharedLibraries [
     "-DLLVM_LINK_LLVM_DYLIB=ON"
   ] ++ stdenv.lib.optional (!isDarwin)
@@ -103,7 +108,9 @@ in stdenv.mkDerivation rec {
     export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PWD/lib
   '';
 
-  postInstall = ""
+  postInstall = ''
+    moveToOutput "share/man" "$man"
+  ''
   + stdenv.lib.optionalString (enableSharedLibraries) ''
     moveToOutput "lib/libLLVM-*" "$lib"
     moveToOutput "lib/libLLVM.${shlib}" "$lib"