gnu: Add cling.

* gnu/packages/cpp.scm (cling): New variable.
(llvm-cling): New private variable.
(clang-cling): Likewise.
* gnu/packages/patches/cling-use-shared-library.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register it.

2 files changed, 522 insertions, 1 deletions

diff --git a/gnu/packages/cpp.scm b/gnu/packages/cpp.scm
index 37dd5ceec4..042658695c 100644
--- a/gnu/packages/cpp.scm
+++ b/gnu/packages/cpp.scm
@@ -21,6 +21,8 @@
 ;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;; Copyright © 2021 Nicolò Balzarotti <nicolo@nixo.xyz>
 ;;; Copyright © 2021 Guillaume Le Vaillant <glv@posteo.net>
+;;; Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -43,6 +45,7 @@
   #:use-module (guix download)
   #:use-module (guix utils)
   #:use-module (guix git-download)
+  #:use-module ((guix build utils) #:hide (delete))
   #:use-module (guix build-system cmake)
   #:use-module (guix build-system gnu)
   #:use-module (guix build-system python)
@@ -61,6 +64,7 @@
   #:use-module (gnu packages documentation)
   #:use-module (gnu packages gcc)
   #:use-module (gnu packages libevent)
+  #:use-module (gnu packages libffi)
   #:use-module (gnu packages libunwind)
   #:use-module (gnu packages linux)
   #:use-module (gnu packages llvm)
@@ -72,9 +76,11 @@
   #:use-module (gnu packages pkg-config)
   #:use-module (gnu packages popt)
   #:use-module (gnu packages pretty-print)
+  #:use-module (gnu packages python)
   #:use-module (gnu packages tls)
   #:use-module (gnu packages web)
-  #:use-module (gnu packages xml))
+  #:use-module (gnu packages xml)
+  #:use-module (srfi srfi-1))
 
 (define-public range-v3
   (package
@@ -1357,6 +1363,192 @@ of reading and writing XML.")
     ;; details.
     (license license:gpl2+)))
 
+(define %cling-version "0.9")
+
+(define llvm-cling             ;LLVM 9 with approximately 10 patches for cling
+  (let ((base llvm-9))
+    (package/inherit base
+      (name "llvm-cling")
+      (source
+       (origin
+         (inherit (package-source base))
+         (method git-fetch)
+         (uri (git-reference
+               (url "http://root.cern/git/llvm.git")
+               (commit (string-append "cling-v" %cling-version))))
+         (file-name (git-file-name "llvm-cling" %cling-version))
+         (sha256
+          (base32
+           "0y3iwv3c9152kybmdrwvadggjs163r25h7rmlxzr3hfpr463pnwf"))
+         (modules '((guix build utils)))
+         (snippet
+          ;; The source is missing an include directive (see:
+          ;; https://github.com/vgvassilev/cling/issues/219).
+          '(substitute* "utils/benchmark/src/benchmark_register.h"
+             (("^#include <vector>.*" all)
+              (string-append all "#include <limits>\n"))))))
+      (outputs '("out"))
+      (arguments
+       (substitute-keyword-arguments (package-arguments base)
+         ((#:configure-flags _ ''())
+          '(list "-DLLVM_PARALLEL_LINK_JOBS=1" ;cater to smaller build machines
+                 ;; Only enable compiler support for the host architecture to
+                 ;; save on build time.
+                 "-DLLVM_TARGETS_TO_BUILD=host;NVPTX"
+                 "-DLLVM_INSTALL_UTILS=ON"
+                 "-DLLVM_ENABLE_RTTI=ON"
+                 "-DLLVM_ENABLE_FFI=ON"
+                 "-DLLVM_BUILD_LLVM_DYLIB=ON"
+                 "-DLLVM_LINK_LLVM_DYLIB=ON"))
+         ((#:phases phases '%standard-phases)
+          `(modify-phases ,phases
+             (delete 'shared-lib-workaround)
+             (delete 'install-opt-viewer))))))))
+
+(define clang-cling-runtime
+  (let ((base clang-runtime-9))
+    (package/inherit base
+      (name "clang-cling-runtime")
+      (arguments
+       (substitute-keyword-arguments (package-arguments base)
+         ((#:phases phases '%standard-phases)
+          `(modify-phases ,phases
+             (add-after 'install 'delete-static-libraries
+               ;; This reduces the size from 22 MiB to 4 MiB.
+               (lambda* (#:key outputs #:allow-other-keys)
+                 (let ((out (assoc-ref outputs "out")))
+                   (for-each delete-file (find-files out "\\.a$")))))))))
+      (inputs (alist-replace "llvm" `(,llvm-cling)
+                             (package-inputs base))))))
+
+(define clang-cling              ;modified clang 9 with ~ 60 patches for cling
+  (let ((base clang-9))
+    (package/inherit base
+      (name "clang-cling")
+      (source
+       (origin
+         (inherit (package-source base))
+         (method git-fetch)
+         (uri (git-reference
+               (url "http://root.cern/git/clang.git")
+               (commit (string-append "cling-v" %cling-version))))
+         (file-name (git-file-name "clang-cling" %cling-version))
+         (sha256
+          (base32
+           "128mxkwghss6589wvm6amzv183aq88rdrnfxjiyjcji5hx84vpby"))))
+      (arguments
+       (substitute-keyword-arguments (package-arguments base)
+         ((#:phases phases '%standard-phases)
+          `(modify-phases ,phases
+             (add-after 'install 'delete-static-libraries
+               ;; This reduces the size by half, from 220 MiB to 112 MiB.
+               (lambda* (#:key outputs #:allow-other-keys)
+                 (let ((out (assoc-ref outputs "out")))
+                   (for-each delete-file (find-files out "\\.a$")))))))))
+      (propagated-inputs (fold alist-replace
+                               (package-propagated-inputs base)
+                               '("llvm" "clang-runtime")
+                               `((,llvm-cling) (,clang-cling-runtime)))))))
+
+(define-public cling
+  ;; The tagged v0.9 release doesn't build, so use the latest commit.
+  (let ((commit "d78d1a03fedfd2bf6d2b6ff295aca576d98940df")
+        (revision "1")
+        (version* "0.9"))
+    (package
+      (name "cling")
+      (version (git-version version* revision commit))
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                      (url "http://root.cern/git/cling.git")
+                      (commit commit)))
+                (file-name (git-file-name name version))
+                (sha256
+                 (base32
+                  "0lsbxv21b4qw11xkw9iipdpca64jjwwqxm0qf5v2cgdlibf8m8n9"))
+                ;; Patch submitted upstream here:
+                ;; https://github.com/root-project/cling/pull/433.
+                (patches (search-patches "cling-use-shared-library.patch"))))
+      (build-system cmake-build-system)
+      (arguments
+       `(#:build-type "Release"         ;keep the build as lean as possible
+         #:tests? #f                    ;FIXME: 78 tests fail (out of ~200)
+         #:test-target "check-cling"
+         #:configure-flags
+         (list (string-append "-DCLING_CXX_PATH="
+                              (assoc-ref %build-inputs "gcc") "/bin/g++")
+               ;; XXX: The AddLLVM.cmake module expects LLVM_EXTERNAL_LIT to
+               ;; be a Python script, not a shell executable.
+               (string-append "-DLLVM_EXTERNAL_LIT="
+                              (assoc-ref %build-inputs "python-lit")
+                              "/bin/.lit-real"))
+         #:phases
+         (modify-phases %standard-phases
+           (add-after 'unpack 'set-version
+             (lambda _
+               (make-file-writable "VERSION")
+               (call-with-output-file "VERSION"
+                 (lambda (port)
+                   (format port "~a~%" ,version)))))
+           (add-after 'unpack 'patch-paths
+             (lambda* (#:key inputs #:allow-other-keys)
+               (substitute* "lib/Interpreter/CIFactory.cpp"
+                 (("\bsed\b")
+                  (which "sed"))
+                 ;; This ensures that the default C++ library used by Cling is
+                 ;; that of the compiler that was used to build it, rather
+                 ;; than that of whatever g++ happens to be on PATH.
+                 (("ReadCompilerIncludePaths\\(CLING_CXX_RLTV")
+                  (string-append "ReadCompilerIncludePaths(\""
+                                 (assoc-ref inputs "gcc") "/bin/g++\""))
+                 ;; Cling uses libclang's CompilerInvocation::GetResourcesPath
+                 ;; to resolve Clang's library prefix, but this fails on Guix
+                 ;; because it is relative to the output of cling rather than
+                 ;; clang (see:
+                 ;; https://github.com/root-project/cling/issues/434).  Fully
+                 ;; shortcut the logic in this method to return the correct
+                 ;; static location.
+                 (("static std::string getResourceDir.*" all)
+                  (string-append all
+                                 "    return std::string(\""
+                                 (assoc-ref inputs "clang-cling")
+                                 "/lib/clang/" ,(package-version clang-cling)
+                                 "\");")))
+               ;; Check for the 'lit' command for the tests, not 'lit.py'
+               ;; (see: https://github.com/root-project/cling/issues/432).
+               (substitute* "CMakeLists.txt"
+                 (("lit.py")
+                  "lit"))))
+           (add-after 'unpack 'adjust-lit.cfg
+             ;; See: https://github.com/root-project/cling/issues/435.
+             (lambda _
+               (substitute* "test/lit.cfg"
+                 (("config.llvm_tools_dir \\+ '")
+                  "config.cling_obj_root + '/bin"))))
+           (add-after 'install 'delete-static-libraries
+             ;; This reduces the size from 17 MiB to 5.4 MiB.
+             (lambda* (#:key outputs #:allow-other-keys)
+               (let ((out (assoc-ref outputs "out")))
+                 (for-each delete-file (find-files out "\\.a$"))))))))
+      (native-inputs
+       `(("python" ,python)
+         ("python-lit" ,python-lit)))
+      (inputs
+       `(("clang-cling" ,clang-cling)
+         ("llvm-cling" ,llvm-cling)))
+      (home-page "https://root.cern/cling/")
+      (synopsis "Interactive C++ interpreter")
+      (description "Cling is an interactive C++17 standard compliant
+interpreter, built on top of LLVM and Clang.  Cling can be used as a
+read-eval-print loop (REPL) to assist with rapid application development.
+Here's how to print @samp{\"Hello World!\"} using @command{cling}:
+
+@example
+cling '#include <stdio.h>' 'printf(\"Hello World!\\n\");'
+@end example")
+      (license license:lgpl2.1+))))     ;for the combined work
+
 (define-public jsonnet
   (package
     (name "jsonnet")
diff --git a/gnu/packages/patches/cling-use-shared-library.patch b/gnu/packages/patches/cling-use-shared-library.patch
new file mode 100644
index 0000000000..6385b307b3
--- /dev/null
+++ b/gnu/packages/patches/cling-use-shared-library.patch
@@ -0,0 +1,329 @@
+From 811f0a575231496318b5e9c9a0ff0ed195b16dc0 Mon Sep 17 00:00:00 2001
+From: Maxim Cournoyer <maxim.cournoyer@gmail.com>
+Date: Tue, 7 Sep 2021 16:35:07 -0400
+Subject: [PATCH] build: Allow building Cling using the Clang shared library.
+
+The officially supported way to build LLVM/Clang as a shared library
+is via the LLVM_BUILD_LLVM_DYLIB and LLVM_LINK_LLVM_DYLIB CMake
+options (see: https://llvm.org/docs/BuildingADistribution.html).  When
+built this way, the whole of Clang API is exposed as a shared
+library (libclang-cpp.so).
+
+* CMakeLists.txt: Query if we're in shared mode via llvm-config, and
+register the result as LLVM_LIB_IS_SHARED.
+[LLVM_LIB_IS_SHARED] <target_link_libraries>: Use the PUBLIC interface of the
+LLVM shared library.
+* lib/Interpreter/CMakeLists.txt [LLVM_LIB_IS_SHARED]: When defined, replace the
+individual Clang components by clang-cpp.
+* lib/MetaProcessor/CMakeLists.txt: Likewise.
+* lib/Utils/CMakeLists.txt: Likewise.
+* tools/Jupyter/CMakeLists.txt: Likewise.
+* tools/driver/CMakeLists.txt: Likewise.
+* tools/libcling/CMakeLists.txt: Likewise.
+---
+ CMakeLists.txt                   | 10 ++++++--
+ lib/Interpreter/CMakeLists.txt   | 40 ++++++++++++++++++--------------
+ lib/MetaProcessor/CMakeLists.txt | 16 +++++++++----
+ lib/Utils/CMakeLists.txt         | 34 +++++++++++++++------------
+ tools/Jupyter/CMakeLists.txt     | 11 ++++++++-
+ tools/driver/CMakeLists.txt      | 16 +++----------
+ tools/libcling/CMakeLists.txt    | 38 +++++++++++++++---------------
+ 7 files changed, 93 insertions(+), 72 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 65b14b27..888f7ee9 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -23,6 +23,7 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
+       "--libdir"
+       "--includedir"
+       "--prefix"
++      "--shared-mode"
+       "--src-root")
+     execute_process(
+       COMMAND ${CONFIG_COMMAND}
+@@ -47,7 +48,8 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
+   list(GET CONFIG_OUTPUT 2 LIBRARY_DIR)
+   list(GET CONFIG_OUTPUT 3 INCLUDE_DIR)
+   list(GET CONFIG_OUTPUT 4 LLVM_OBJ_ROOT)
+-  list(GET CONFIG_OUTPUT 5 MAIN_SRC_DIR)
++  list(GET CONFIG_OUTPUT 5 LLVM_LIB_IS_SHARED)
++  list(GET CONFIG_OUTPUT 6 MAIN_SRC_DIR)
+ 
+   if(NOT MSVC_IDE)
+     set(LLVM_ENABLE_ASSERTIONS ${ENABLE_ASSERTIONS}
+@@ -427,7 +429,11 @@ macro(add_cling_library name)
+   endif()
+ 
+   if(TARGET ${name})
+-    target_link_libraries(${name} INTERFACE ${LLVM_COMMON_LIBS})
++      if(LLVM_LIB_IS_SHARED)
++          target_link_libraries(${name} PUBLIC LLVM)
++      else()
++          target_link_libraries(${name} INTERFACE ${LLVM_COMMON_LIBS})
++      endif()
+ 
+     if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "libcling")
+       install(TARGETS ${name}
+diff --git a/lib/Interpreter/CMakeLists.txt b/lib/Interpreter/CMakeLists.txt
+index 921c773c..af65c020 100644
+--- a/lib/Interpreter/CMakeLists.txt
++++ b/lib/Interpreter/CMakeLists.txt
+@@ -6,22 +6,28 @@
+ # LICENSE.TXT for details.
+ #------------------------------------------------------------------------------
+ 
+-set(LIBS
+-  clingUtils
+-  clangCodeGen
+-  clangDriver
+-  clangFrontend
+-  clangParse
+-  clangSema
+-  clangAnalysis
+-  clangEdit
+-  clangRewrite
+-  clangRewriteFrontend
+-  clangSerialization
+-  clangAST
+-  clangBasic
+-  clangLex
+-)
++if (LLVM_LIB_IS_SHARED)
++    set(LIBS
++        clang-cpp
++        clingUtils)
++else()
++    set(LIBS
++        clingUtils
++        clangCodeGen
++        clangDriver
++        clangFrontend
++        clangParse
++        clangSema
++        clangAnalysis
++        clangEdit
++        clangRewrite
++        clangRewriteFrontend
++        clangSerialization
++        clangAST
++        clangBasic
++        clangLex
++        )
++endif()
+ 
+ set(LLVM_LINK_COMPONENTS
+   analysis
+@@ -369,4 +375,4 @@ if ((NOT builtin_llvm) AND builtin_clang)
+   get_property(P SOURCE TransactionUnloader.cpp PROPERTY INCLUDE_DIRECTORIES)
+   list(INSERT P 0 ${FixInclude})
+   set_property(SOURCE TransactionUnloader.cpp PROPERTY INCLUDE_DIRECTORIES "${P}")
+-endif()
+\ No newline at end of file
++endif()
+diff --git a/lib/MetaProcessor/CMakeLists.txt b/lib/MetaProcessor/CMakeLists.txt
+index e753dca3..5f4641bb 100644
+--- a/lib/MetaProcessor/CMakeLists.txt
++++ b/lib/MetaProcessor/CMakeLists.txt
+@@ -10,7 +10,16 @@ set( LLVM_LINK_COMPONENTS
+   core
+   support
+   binaryformat
+-)
++  )
++
++if (LLVM_LIB_IS_SHARED)
++    set(LIBS clang-cpp)
++else()
++    set(LIBS
++        clangLex
++        clangAST
++        clangBasic)
++endif()
+ 
+ add_cling_library(clingMetaProcessor OBJECT
+   Display.cpp
+@@ -21,10 +30,7 @@ add_cling_library(clingMetaProcessor OBJECT
+   MetaSema.cpp
+ 
+   LINK_LIBS
+-  clangLex
+-  clangAST
+-  clangBasic
+-
++  ${LIBS}
+   clingInterpreter
+   clingUtils
+ )
+diff --git a/lib/Utils/CMakeLists.txt b/lib/Utils/CMakeLists.txt
+index 327c9fff..fbe4bd87 100644
+--- a/lib/Utils/CMakeLists.txt
++++ b/lib/Utils/CMakeLists.txt
+@@ -26,21 +26,25 @@ set(LLVM_LINK_COMPONENTS
+   ${LLVM_TARGETS_TO_BUILD}
+ )
+ 
+-set(LIBS
+-  clangCodeGen
+-  clangDriver
+-  clangFrontend
+-  clangParse
+-  clangSema
+-  clangAnalysis
+-  clangEdit
+-  clangRewrite
+-  clangRewriteFrontend
+-  clangSerialization
+-  clangAST
+-  clangBasic
+-  clangLex
+-)
++if (LLVM_LIB_IS_SHARED)
++    set(LIBS clang-cpp)
++else()
++    set(LIBS
++        clangCodeGen
++        clangDriver
++        clangFrontend
++        clangParse
++        clangSema
++        clangAnalysis
++        clangEdit
++        clangRewrite
++        clangRewriteFrontend
++        clangSerialization
++        clangAST
++        clangBasic
++        clangLex
++        )
++endif()
+ 
+ find_library(DL_LIBRARY_PATH dl)
+ if (DL_LIBRARY_PATH)
+diff --git a/tools/Jupyter/CMakeLists.txt b/tools/Jupyter/CMakeLists.txt
+index aad5f3f7..8b4ac36f 100644
+--- a/tools/Jupyter/CMakeLists.txt
++++ b/tools/Jupyter/CMakeLists.txt
+@@ -39,6 +39,14 @@ else()
+    endif()
+ endif()
+ 
++if (LLVM_LIB_IS_SHARED)
++    set(LIBS
++        clang-cpp
++        clingUserInterface
++        clingMetaProcessor
++        ${INTERPRETER}
++        clingUtils)
++else()
+ set(LIBS
+         clangAST
+         clangBasic
+@@ -54,7 +62,8 @@ set(LIBS
+         clingMetaProcessor
+         ${INTERPRETER}
+         clingUtils
+-    )
++        )
++endif()
+ 
+ if( LLVM_ENABLE_PIC )
+     set(ENABLE_SHARED SHARED)
+diff --git a/tools/driver/CMakeLists.txt b/tools/driver/CMakeLists.txt
+index 1968b97f..5ed53fb7 100644
+--- a/tools/driver/CMakeLists.txt
++++ b/tools/driver/CMakeLists.txt
+@@ -9,23 +9,13 @@
+ # Keep symbols for JIT resolution
+ set(LLVM_NO_DEAD_STRIP 1)
+ 
+-if(BUILD_SHARED_LIBS)
+-  set(LIBS
+-    LLVMSupport
+-
+-    clangFrontendTool
+-
+-    clingInterpreter
+-    clingMetaProcessor
+-    clingUserInterface
+-    clingUtils
+-  )
++if(LLVM_LIB_IS_SHARED)
++  set(LIBS clang-cpp clingUserInterface)
+   add_cling_executable(cling
+     cling.cpp
+   )
+ else()
+   set(LIBS
+-    LLVMSupport
+ 
+     clangASTMatchers
+     clangFrontendTool
+@@ -38,7 +28,7 @@ else()
+     $<TARGET_OBJECTS:obj.clingMetaProcessor>
+     $<TARGET_OBJECTS:obj.clingUtils>
+   )
+-endif(BUILD_SHARED_LIBS)
++endif(LLVM_LIB_IS_SHARED)
+ 
+ set_target_properties(cling
+   PROPERTIES ENABLE_EXPORTS 1)
+diff --git a/tools/libcling/CMakeLists.txt b/tools/libcling/CMakeLists.txt
+index 143d3bdb..ba000d44 100644
+--- a/tools/libcling/CMakeLists.txt
++++ b/tools/libcling/CMakeLists.txt
+@@ -10,21 +10,25 @@ set(SOURCES
+   ADDITIONAL_HEADERS
+   )
+ 
+-set(LIBS
+-  clangAnalysis
+-  clangDriver
+-  clangFrontend
+-  clangParse
+-  clangSema
+-  clangAST
+-  clangLex
+-  clangSerialization
+-  clangCodeGen
+-  clangBasic
+-  clangEdit
+-
+-  clingUtils
+-)
++if (LLVM_LIB_IS_SHARED)
++    set(LIBS clang-cpp)
++else()
++    set(LIBS
++        clangAnalysis
++        clangDriver
++        clangFrontend
++        clangParse
++        clangSema
++        clangAST
++        clangLex
++        clangSerialization
++        clangCodeGen
++        clangBasic
++        clangEdit
++
++        clingUtils
++        )
++endif()
+ 
+ set( LLVM_LINK_COMPONENTS
+   analysis
+@@ -63,10 +67,6 @@ option(LIBCLING_BUILD_STATIC
+ #  set(LLVM_EXPORTED_SYMBOL_FILE)
+ #endif()
+ 
+-if( LLVM_ENABLE_PIC )
+-  set(ENABLE_SHARED SHARED)
+-endif()
+-
+ if((NOT LLVM_ENABLE_PIC OR LIBCLING_BUILD_STATIC) AND NOT WIN32)
+   set(ENABLE_STATIC STATIC)
+ endif()
+-- 
+2.33.0
+