llvmPackages_15.llvm: enable polly by default

this comment has a more complete history: https://github.com/NixOS/nixpkgs/pull/194634#discussion_r1064089830

in short: polly was disabled in the llvm 11 -> llvm 12 copy, mostly by
accident

most of the Polly install dirs patch has been upstreamed; one change
remains

pkgs/development/compilers/llvm/15/default.nix

@@ -1,6 +1,6 @@
 { lowPrio, newScope, pkgs, lib, stdenv, stdenvNoCC, cmake, ninja
 , gccForLibs, preLibcCrossHeaders
-, libxml2, python3, isl, fetchFromGitHub, overrideCC, wrapCCWith, wrapBintoolsWith
+, libxml2, python3, fetchFromGitHub, overrideCC, wrapCCWith, wrapBintoolsWith
 , buildLlvmTools # tools, but from the previous stage, for cross
 , targetLlvmLibraries # libraries, but from the next stage, for cross
 , targetLlvm
@@ -41,7 +41,7 @@ let
   };
 
   tools = lib.makeExtensible (tools: let
-    callPackage = newScope (tools // { inherit stdenv cmake ninja libxml2 python3 isl release_version version monorepoSrc buildLlvmTools; });
+    callPackage = newScope (tools // { inherit stdenv cmake ninja libxml2 python3 release_version version monorepoSrc buildLlvmTools; });
     mkExtraBuildCommands0 = cc: ''
       rsrc="$out/resource-root"
       mkdir "$rsrc"
@@ -220,7 +220,7 @@ let
   });
 
   libraries = lib.makeExtensible (libraries: let
-    callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake ninja libxml2 python3 isl release_version version monorepoSrc; });
+    callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake ninja libxml2 python3 release_version version monorepoSrc; });
   in {
 
     compiler-rt-libc = callPackage ./compiler-rt {

pkgs/development/compilers/llvm/15/llvm/default.nix

@@ -23,7 +23,7 @@
   # broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
   # broken for the armv7l builder
   && !stdenv.hostPlatform.isAarch
-, enablePolly ? false
+, enablePolly ? true
 } @args:
 
 let
@@ -43,7 +43,8 @@ in stdenv.mkDerivation (rec {
     cp -r ${monorepoSrc}/${pname} "$out"
     cp -r ${monorepoSrc}/third-party "$out"
   '' + lib.optionalString enablePolly ''
-    cp -r ${monorepoSrc}/polly "$out/llvm/tools"
+    chmod u+w "$out/${pname}/tools"
+    cp -r ${monorepoSrc}/polly "$out/${pname}/tools"
   '');
 
   sourceRoot = "${src.name}/${pname}";

pkgs/development/compilers/llvm/15/llvm/gnu-install-dirs-polly.patch

@@ -1,77 +1,7 @@
-diff --git a/tools/polly/CMakeLists.txt b/tools/polly/CMakeLists.txt
+This is the one remaining Polly install dirs related change that hasn't made it
-index ca7c04c565bb..6a6155806ffa 100644
+into upstream yet; previously this patch file also included:
---- a/tools/polly/CMakeLists.txt
+https://reviews.llvm.org/D117541
-+++ b/tools/polly/CMakeLists.txt
+
-@@ -3,6 +3,8 @@ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
-   project(Polly)
-   cmake_minimum_required(VERSION 3.13.4)
- 
-+  include(GNUInstallDirs)
-+
-   # Where is LLVM installed?
-   find_package(LLVM CONFIG REQUIRED)
-   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
-@@ -122,13 +124,13 @@ include_directories(
- 
- if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
-   install(DIRECTORY include/
--    DESTINATION include
-+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-     FILES_MATCHING
-     PATTERN "*.h"
-     )
- 
-   install(DIRECTORY ${POLLY_BINARY_DIR}/include/
--    DESTINATION include
-+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-     FILES_MATCHING
-     PATTERN "*.h"
-     PATTERN "CMakeFiles" EXCLUDE
-diff --git a/tools/polly/cmake/CMakeLists.txt b/tools/polly/cmake/CMakeLists.txt
-index 7cc129ba2e90..137be25e4b80 100644
---- a/tools/polly/cmake/CMakeLists.txt
-+++ b/tools/polly/cmake/CMakeLists.txt
-@@ -79,18 +79,18 @@ file(GENERATE
- 
- # Generate PollyConfig.cmake for the install tree.
- unset(POLLY_EXPORTS)
--set(POLLY_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
-+set(POLLY_INSTALL_PREFIX "")
- set(POLLY_CONFIG_LLVM_CMAKE_DIR "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
--set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
--set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}")
-+set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
-+set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
- if (POLLY_BUNDLED_ISL)
-   set(POLLY_CONFIG_INCLUDE_DIRS
--    "${POLLY_INSTALL_PREFIX}/include"
--    "${POLLY_INSTALL_PREFIX}/include/polly"
-+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}"
-+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}/polly"
-     )
- else()
-   set(POLLY_CONFIG_INCLUDE_DIRS
--    "${POLLY_INSTALL_PREFIX}/include"
-+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_INCLUDEDIR}"
-     ${ISL_INCLUDE_DIRS}
-     )
- endif()
-@@ -100,12 +100,12 @@ endif()
- foreach(tgt IN LISTS POLLY_CONFIG_EXPORTED_TARGETS)
-   get_target_property(tgt_type ${tgt} TYPE)
-   if (tgt_type STREQUAL "EXECUTABLE")
--    set(tgt_prefix "bin/")
-+    set(tgt_prefix "${CMAKE_INSTALL_BINDIR}/")
-   else()
--    set(tgt_prefix "lib/")
-+    set(tgt_prefix "${CMAKE_INSTALL_LIBDIR}/")
-   endif()
- 
--  set(tgt_path "${CMAKE_INSTALL_PREFIX}/${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
-+  set(tgt_path "${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
-   file(RELATIVE_PATH tgt_path ${POLLY_CONFIG_CMAKE_DIR} ${tgt_path})
- 
-   if (NOT tgt_type STREQUAL "INTERFACE_LIBRARY")
 diff --git a/tools/polly/cmake/polly_macros.cmake b/tools/polly/cmake/polly_macros.cmake
 index 518a09b45a42..bd9d6f5542ad 100644
 --- a/tools/polly/cmake/polly_macros.cmake
@@ -87,16 +17,3 @@ index 518a09b45a42..bd9d6f5542ad 100644
    endif()
    set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
  endmacro(add_polly_library)
-diff --git a/tools/polly/lib/External/CMakeLists.txt b/tools/polly/lib/External/CMakeLists.txt
-index e3a5683fccdc..293b482eb28a 100644
---- a/tools/polly/lib/External/CMakeLists.txt
-+++ b/tools/polly/lib/External/CMakeLists.txt
-@@ -290,7 +290,7 @@ if (POLLY_BUNDLED_ISL)
-     install(DIRECTORY
-       ${ISL_SOURCE_DIR}/include/
-       ${ISL_BINARY_DIR}/include/
--      DESTINATION include/polly
-+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/polly
-       FILES_MATCHING
-       PATTERN "*.h"
-       PATTERN "CMakeFiles" EXCLUDE