Fix detection of clang libraries for clang-9+ (#923)

In some installation of recent clang libraries (probably 9 and later), the libraries are shipped as a single library on some platforms.
MeteoSwiss-APN · May 6, 2020 · e65d66b · e65d66b
1 parent 64e1fe2
commit e65d66b
Show file tree

Hide file tree

Showing 3 changed files with 66 additions and 52 deletions.
diff --git a/docker/cuda10.1-ubuntu18.04.dockerfile b/docker/cuda10.1-ubuntu18.04.dockerfile
@@ -14,7 +14,7 @@ RUN apt update && apt install -y --no-install-recommends \
     build-essential openssh-client git \
     kitware-archive-keyring cmake ninja-build \
     gcc-8 g++-8 \
-    llvm-9-dev libclang-9-dev \
+    llvm-9-dev libclang-9-dev libclang-cpp9 \
     python3 libpython3-dev python3-pip python3-setuptools python3-wheel \
     libboost-dev && apt clean
 RUN python3 -m pip install --upgrade pip

diff --git a/docker/ubuntu19.10.dockerfile b/docker/ubuntu19.10.dockerfile
@@ -1,7 +1,7 @@
 FROM ubuntu:eoan
 RUN apt update && apt install -y --no-install-recommends \
     build-essential ninja-build cmake git openssh-client curl \
-    llvm-9-dev libclang-9-dev \
+    llvm-9-dev libclang-9-dev libclang-cpp9 \
     python3 python3-pip libpython3-dev \
     python3-setuptools python3-wheel \
     libboost-dev && apt clean

diff --git a/gtclang/cmake/FindClang.cmake b/gtclang/cmake/FindClang.cmake
@@ -34,7 +34,7 @@ if(LLVM_FOUND)
     OUTPUT_VARIABLE llvm_install_prefix
     OUTPUT_STRIP_TRAILING_WHITESPACE
   )
-set(CLANG_RESSOURCE_INCLUDE_PATH "${llvm_install_prefix}/lib/clang/${LLVM_VERSION}/include")
+  set(CLANG_RESSOURCE_INCLUDE_PATH "${llvm_install_prefix}/lib/clang/${LLVM_VERSION}/include")
 
   # potentially add include dir from binary dir for non-installed LLVM
   execute_process(
@@ -49,65 +49,79 @@ set(CLANG_RESSOURCE_INCLUDE_PATH "${llvm_install_prefix}/lib/clang/${LLVM_VERSIO
     message(STATUS
       "Detected that llvm-config comes from a build-tree, adding more include directories for Clang")
     list(APPEND CLANG_INCLUDE_DIRS
-         "${llvm_install_prefix}/tools/clang/include" # build dir
+         "${llvm_install_prefix}/tools/clang/include"  # build dir
          "${llvm_source_root}/tools/clang/include"     # source dir
     )
   endif()
 
-  # TODO test this set with all supported LLVM versions
-  # 6: done
-  # 7: done
-  # 8: done
-  # 9
-  # 10 (master):
-  set(clang_libnames
-    clangFrontend
-    clangARCMigrate
-    clangASTMatchers
-    clangAnalysis
-    clangCodeGen
-    clangDriver
-    clangEdit
-    clangFormat
-    clangFrontendTool
-    clangIndex
-    clangParse
-    clangRewrite
-    clangRewriteFrontend
-    clangSema
-    clangAnalysis
-    clangSerialization
-    clangStaticAnalyzerCheckers
-    clangStaticAnalyzerCore
-    clangTooling
-    clangToolingCore
-    clangAST
-    clangLex
-    clangBasic
-  )
-  if(${LLVM_VERSION} VERSION_GREATER_EQUAL 7.0.0)
-    list(APPEND clang_libnames clangToolingInclusions)
-  endif()
-
   add_library(Clang INTERFACE IMPORTED GLOBAL)
   add_library(Clang::Clang ALIAS Clang)
   target_include_directories(Clang INTERFACE ${CLANG_INCLUDE_DIRS})
   target_compile_features(Clang INTERFACE cxx_std_11)
-  foreach(_lib ${clang_libnames})
-    find_library(${_lib}_LIBRARY ${_lib}
-      HINTS ${CLANG_LIBRARY_DIRS} ${LLVM_ROOT}
-      PATH_SUFFIXES lib
-      )
-    mark_as_advanced(${_lib}_LIBRARY)
-    list(APPEND CLANG_LIBS ${${_lib}_LIBRARY})
-    if(${_lib}_LIBRARY)
-      target_link_libraries(Clang INTERFACE ${${_lib}_LIBRARY})
-    else()
-      message(FATAL_ERROR "Could not find ${_lib} library: Try setting CLANG_LIBRARY_DIRS or LLVM_ROOT")
+
+  # Clang-9 includes a single-library version (libclang-cpp9 on Debian systems)
+  find_library(single_clang_lib clang-cpp
+    PATHS ${LLVM_LIBRARY_DIRS}
+    NO_DEFAULT_PATH
+    NO_PACKAGE_ROOT_PATH
+    NO_CMAKE_PATH
+    NO_CMAKE_ENVIRONMENT_PATH
+    NO_SYSTEM_ENVIRONMENT_PATH
+    NO_CMAKE_SYSTEM_PATH
+  )
+  mark_as_advanced(single_clang_lib)
+
+  if(single_clang_lib)
+    # Single library installation is available
+    list(APPEND CLANG_LIBS ${single_clang_lib})
+    target_link_libraries(Clang INTERFACE ${single_clang_lib})
+  else()
+    set(clang_libnames
+      clangFrontend
+      clangARCMigrate
+      clangASTMatchers
+      clangAnalysis
+      clangCodeGen
+      clangDriver
+      clangEdit
+      clangFormat
+      clangFrontendTool
+      clangIndex
+      clangParse
+      clangRewrite
+      clangRewriteFrontend
+      clangSema
+      clangAnalysis
+      clangSerialization
+      clangStaticAnalyzerCheckers
+      clangStaticAnalyzerCore
+      clangTooling
+      clangToolingCore
+      clangAST
+      clangLex
+      clangBasic
+    )
+    if(${LLVM_VERSION} VERSION_GREATER_EQUAL 7.0.0)
+      list(APPEND clang_libnames clangToolingInclusions)
     endif()
-  endforeach()
+
+    foreach(_lib ${clang_libnames})
+      find_library(${_lib}_LIBRARY ${_lib}
+        HINTS ${CLANG_LIBRARY_DIRS} ${LLVM_ROOT}
+        PATH_SUFFIXES lib
+      )
+      mark_as_advanced(${_lib}_LIBRARY)
+      list(APPEND CLANG_LIBS ${${_lib}_LIBRARY})
+      if(${_lib}_LIBRARY)
+        target_link_libraries(Clang INTERFACE ${${_lib}_LIBRARY})
+      else()
+        message(FATAL_ERROR "Could not find ${_lib} library: Try setting CLANG_LIBRARY_DIRS or LLVM_ROOT")
+      endif()
+    endforeach()
+  endif()
+
 else()
-  message(FATAL_ERROR "Could NOT find Clang")
+  message(FATAL_ERROR "LLVM NOT Found")
 endif()
 
 include(FindPackageHandleStandardArgs)