From b70e093e1ce01de0f607d70911e1539462c17a40 Mon Sep 17 00:00:00 2001
From: Zhu Zihao <all_but_last@163.com>
Date: Sat, 8 Oct 2022 16:26:44 +0800
Subject: [PATCH 2/2] gnu: libcxx: Update to 14.0.6.

* gnu/packages/llvm.scm(libcxx)[source]: Use "llvm-monorepo".
[arguments]<#:configure-flags>: Use clang & clang++, skip RPATH_CHANGE in CMake.
<#:phases>: Add phase "enter-subdirectory".
[native-inputs]: Add Python 3 for lit.

(libcxx-6)[arguments]: Don't inherit from libcxx.
---
 gnu/packages/llvm.scm | 47 +++++++++++++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 13 deletions(-)

diff --git a/gnu/packages/llvm.scm b/gnu/packages/llvm.scm
index 00918bfb90..ad0cb088be 100644
--- a/gnu/packages/llvm.scm
+++ b/gnu/packages/llvm.scm
@@ -1531,19 +1531,27 @@ (define-public lldb
 (define-public libcxx
   (package
     (name "libcxx")
-    (version "9.0.1")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (llvm-uri "libcxx" version))
-       (sha256
-        (base32
-         "0d2bj5i6mk4caq7skd5nsdmz8c2m5w5anximl5wz3x32p08zz089"))))
+    (version "14.0.6")
+    (source (llvm-monorepo version))
     (build-system cmake-build-system)
     (arguments
      (list
+      #:tests? #f
+      #:configure-flags
+      #~(list "-DLLVM_ENABLE_RUNTIMES=libcxx;libcxxabi"
+              "-DCMAKE_C_COMPILER=clang"
+              "-DCMAKE_CXX_COMPILER=clang++"
+              ;; libc++.so is actually a GNU ld style linker script, however,
+              ;; CMake still tries to fix the RUNPATH of it during the install
+              ;; step. This argument tells CMake to use the install directory
+              ;; as RUNPATH and don't attempt to patch it.
+              ;; See also: https://gitlab.kitware.com/cmake/cmake/-/issues/22963
+              "-DCMAKE_BUILD_WITH_INSTALL_RPATH=TRUE")
       #:phases
       #~(modify-phases %standard-phases
+          (add-after 'unpack 'enter-subdirectory
+            (lambda _
+              (chdir "runtimes")))
           (add-after 'set-paths 'adjust-CPLUS_INCLUDE_PATH
             (lambda* (#:key inputs #:allow-other-keys)
               (let ((gcc (assoc-ref inputs  "gcc")))
@@ -1559,7 +1567,7 @@ (define-public libcxx
                         (getenv "CPLUS_INCLUDE_PATH"))
                 #t))))))
     (native-inputs
-     (list clang llvm))
+     (list clang llvm python))
     (home-page "https://libcxx.llvm.org")
     (synopsis "C++ standard library")
     (description
@@ -1581,10 +1589,23 @@ (define-public libcxx-6
         (base32
          "0rzw4qvxp6qx4l4h9amrq02gp7hbg8lw4m0sy3k60f50234gnm3n"))))
     (arguments
-     (substitute-keyword-arguments (package-arguments libcxx)
-       ((#:phases p)
-        #~(modify-phases #$p
-            (delete 'enter-subdirectory)))))
+     (list
+      #:phases
+      #~(modify-phases %standard-phases
+          (add-after 'set-paths 'adjust-CPLUS_INCLUDE_PATH
+            (lambda* (#:key inputs #:allow-other-keys)
+              (let ((gcc (assoc-ref inputs  "gcc")))
+                ;; Hide GCC's C++ headers so that they do not interfere with
+                ;; the ones we are attempting to build.
+                (setenv "CPLUS_INCLUDE_PATH"
+                        (string-join (delete (string-append gcc "/include/c++")
+                                             (string-split (getenv "CPLUS_INCLUDE_PATH")
+                                                           #\:))
+                                     ":"))
+                (format #t
+                        "environment variable `CPLUS_INCLUDE_PATH' changed to ~a~%"
+                        (getenv "CPLUS_INCLUDE_PATH"))
+                #t))))))
     (native-inputs
      (list clang-6 llvm-6))))
 
-- 
2.37.3