[cmake] Use GNUInstallDirs to support custom installation dirs.

This is the original patch in my GNUInstallDirs series, now last to merge as the final piece!

It arose as a new draft of D28234. I initially did the unorthodox thing of pushing to that when I wasn't the original author, but since I ended up

 - Using `GNUInstallDirs`, rather than mimicking it, as the original author was hesitant to do but others requested.

 - Converting all the packages, not just LLVM, effecting many more projects than LLVM itself.

I figured it was time to make a new revision.

I have used this patch series (and many back-ports) as the basis of NixOS/nixpkgs#111487 for my distro (NixOS), which was merged last spring (2021). It looked like people were generally on board in D28234, but I make note of this here in case extra motivation is useful.

---

As pointed out in the original issue, a central tension is that LLVM already has some partial support for these sorts of things. Variables like `COMPILER_RT_INSTALL_PATH` have already been dealt with. Variables like `LLVM_LIBDIR_SUFFIX` however, will require further work, so that we may use `CMAKE_INSTALL_LIBDIR`.

These remaining items will be addressed in further patches. What is here is now rote and so we should get it out of the way before dealing more intricately with the remainder.

Reviewed By: #libunwind, #libc, #libc_abi, compnerd

Differential Revision: https://reviews.llvm.org/D99484

clang-tools-extra/CMakeLists.txt

@@ -1,4 +1,5 @@
 include(CMakeDependentOption)
+include(GNUInstallDirs)
 
 option(CLANG_TIDY_ENABLE_STATIC_ANALYZER
   "Include static analyzer checks in clang-tidy" ON)

clang-tools-extra/clang-doc/tool/CMakeLists.txt

@@ -19,9 +19,9 @@ target_link_libraries(clang-doc
   )
 
 install(FILES ../assets/clang-doc-default-stylesheet.css
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-doc)
 
 install(FILES ../assets/index.js
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-doc)

clang-tools-extra/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt

@@ -20,5 +20,5 @@ target_link_libraries(find-all-symbols
   )
 
 install(PROGRAMS run-find-all-symbols.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT find-all-symbols)

clang-tools-extra/clang-include-fixer/tool/CMakeLists.txt

@@ -21,8 +21,8 @@ target_link_libraries(clang-include-fixer
   )
 
 install(PROGRAMS clang-include-fixer.el
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-include-fixer)
 install(PROGRAMS clang-include-fixer.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-include-fixer)

clang-tools-extra/clang-tidy/CMakeLists.txt

@@ -113,7 +113,7 @@ add_subdirectory(utils)
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY .
-    DESTINATION include/clang-tidy
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/clang-tidy"
     COMPONENT clang-tidy-headers
     FILES_MATCHING
     PATTERN "*.h"

clang-tools-extra/clang-tidy/tool/CMakeLists.txt

@@ -52,9 +52,9 @@ target_link_libraries(clang-tidy
 
 
 install(PROGRAMS clang-tidy-diff.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-tidy)
 install(PROGRAMS run-clang-tidy.py
-  DESTINATION bin
+  DESTINATION "${CMAKE_INSTALL_BINDIR}"
   COMPONENT clang-tidy
   RENAME run-clang-tidy)

clang-tools-extra/modularize/CMakeLists.txt

@@ -23,5 +23,5 @@ clang_target_link_libraries(modularize
   )
 
 install(TARGETS modularize
-        RUNTIME DESTINATION bin
+        RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
         COMPONENT clang-extras)

clang/CMakeLists.txt

@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 # If we are not building as a part of LLVM, build Clang as an
 # standalone project, using LLVM as an external library:
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
@@ -424,7 +426,7 @@ include_directories(BEFORE
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY include/clang include/clang-c
-    DESTINATION include
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
     COMPONENT clang-headers
     FILES_MATCHING
     PATTERN "*.def"
@@ -433,7 +435,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
     )
 
   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
-    DESTINATION include
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
     COMPONENT clang-headers
     FILES_MATCHING
     PATTERN "CMakeFiles" EXCLUDE
@@ -453,7 +455,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
 
   add_custom_target(bash-autocomplete DEPENDS utils/bash-autocomplete.sh)
   install(PROGRAMS utils/bash-autocomplete.sh
-          DESTINATION share/clang
+          DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
           COMPONENT bash-autocomplete)
   if(NOT LLVM_ENABLE_IDE)
     add_llvm_install_targets(install-bash-autocomplete

clang/cmake/modules/AddClang.cmake

@@ -1,3 +1,4 @@
+include(GNUInstallDirs)
 include(LLVMDistributionSupport)
 
 function(clang_tablegen)
@@ -120,7 +121,7 @@ macro(add_clang_library name)
           ${export_to_clangtargets}
           LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
           ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-          RUNTIME DESTINATION bin)
+          RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")
 
         if (NOT LLVM_ENABLE_IDE)
           add_llvm_install_targets(install-${lib}
@@ -159,7 +160,7 @@ macro(add_clang_tool name)
     get_target_export_arg(${name} Clang export_to_clangtargets)
     install(TARGETS ${name}
       ${export_to_clangtargets}
-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
       COMPONENT ${name})
 
     if(NOT LLVM_ENABLE_IDE)

clang/tools/c-index-test/CMakeLists.txt

@@ -49,7 +49,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
     set_property(TARGET c-index-test APPEND PROPERTY INSTALL_RPATH
        "@executable_path/../../lib")
   else()
-    set(INSTALL_DESTINATION bin)
+    set(INSTALL_DESTINATION "${CMAKE_INSTALL_BINDIR}")
   endif()
 
   install(TARGETS c-index-test

clang/tools/clang-format/CMakeLists.txt

@@ -21,20 +21,20 @@ if( LLVM_LIB_FUZZING_ENGINE OR LLVM_USE_SANITIZE_COVERAGE )
 endif()
 
 install(PROGRAMS clang-format-bbedit.applescript
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-format)
 install(PROGRAMS clang-format-diff.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-format)
 install(PROGRAMS clang-format-sublime.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-format)
 install(PROGRAMS clang-format.el
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-format)
 install(PROGRAMS clang-format.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-format)
 install(PROGRAMS git-clang-format
-  DESTINATION bin
+  DESTINATION "${CMAKE_INSTALL_BINDIR}"
   COMPONENT clang-format)

clang/tools/clang-nvlink-wrapper/CMakeLists.txt

@@ -22,4 +22,4 @@ target_link_libraries(clang-nvlink-wrapper
   ${CLANG_NVLINK_WRAPPER_LIB_DEPS}
   )
 
-install(TARGETS clang-nvlink-wrapper RUNTIME DESTINATION bin)
+install(TARGETS clang-nvlink-wrapper RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")

clang/tools/clang-rename/CMakeLists.txt

@@ -19,8 +19,8 @@ clang_target_link_libraries(clang-rename
   )
 
 install(PROGRAMS clang-rename.py
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-rename)
 install(PROGRAMS clang-rename.el
-  DESTINATION share/clang
+  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-rename)

clang/tools/libclang/CMakeLists.txt

@@ -186,7 +186,7 @@ endif()
 if(INTERNAL_INSTALL_PREFIX)
   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
 else()
-  set(LIBCLANG_HEADERS_INSTALL_DESTINATION include)
+  set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
 endif()
 
 install(DIRECTORY ../../include/clang-c

clang/tools/scan-build-py/CMakeLists.txt

@@ -43,7 +43,7 @@ foreach(BinFile ${BinFiles})
                          ${CMAKE_BINARY_DIR}/bin/scan-build-py
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/scan-build)
     install (PROGRAMS "bin/scan-build"
-             DESTINATION bin
+             DESTINATION "${CMAKE_INSTALL_BINDIR}"
              RENAME scan-build-py
              COMPONENT scan-build-py)
     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/scan-build-py)
@@ -56,7 +56,7 @@ foreach(BinFile ${BinFiles})
                          ${CMAKE_BINARY_DIR}/bin/
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
     install(PROGRAMS bin/${BinFile}
-            DESTINATION bin
+            DESTINATION "${CMAKE_INSTALL_BINDIR}"
             COMPONENT scan-build-py)
     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
   endif()
@@ -72,7 +72,7 @@ foreach(lib ${LibExecs})
                      DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${lib})
   list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${lib})
   install(PROGRAMS libexec/${lib}
-          DESTINATION libexec
+          DESTINATION "${CMAKE_INSTALL_LIBEXECDIR}"
           COMPONENT scan-build-py)
 endforeach()
 

clang/tools/scan-build/CMakeLists.txt

@@ -47,7 +47,7 @@ if(CLANG_INSTALL_SCANBUILD)
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
     install(PROGRAMS bin/${BinFile}
-            DESTINATION bin
+            DESTINATION "${CMAKE_INSTALL_BINDIR}"
             COMPONENT scan-build)
   endforeach()
 
@@ -61,7 +61,7 @@ if(CLANG_INSTALL_SCANBUILD)
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${LibexecFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${LibexecFile})
     install(PROGRAMS libexec/${LibexecFile}
-            DESTINATION libexec
+            DESTINATION "${CMAKE_INSTALL_LIBEXECDIR}"
             COMPONENT scan-build)
   endforeach()
 
@@ -89,7 +89,7 @@ if(CLANG_INSTALL_SCANBUILD)
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/scan-build/${ShareFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-build/${ShareFile})
     install(FILES share/scan-build/${ShareFile}
-            DESTINATION share/scan-build
+            DESTINATION "${CMAKE_INSTALL_DATADIR}/scan-build"
             COMPONENT scan-build)
   endforeach()
 

clang/tools/scan-view/CMakeLists.txt

@@ -20,7 +20,7 @@ if(CLANG_INSTALL_SCANVIEW)
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
     install(PROGRAMS bin/${BinFile}
-            DESTINATION bin
+            DESTINATION "${CMAKE_INSTALL_BINDIR}"
             COMPONENT scan-view)
   endforeach()
 
@@ -34,7 +34,7 @@ if(CLANG_INSTALL_SCANVIEW)
                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/${ShareFile})
     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-view/${ShareFile})
     install(FILES share/${ShareFile}
-            DESTINATION share/scan-view
+            DESTINATION "${CMAKE_INSTALL_DATADIR}/scan-view"
             COMPONENT scan-view)
   endforeach()
 

clang/utils/hmaptool/CMakeLists.txt

@@ -10,7 +10,7 @@ add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HM
 
 list(APPEND Depends ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HMAPTOOL})
 install(PROGRAMS ${CLANG_HMAPTOOL}
-        DESTINATION bin
+        DESTINATION "${CMAKE_INSTALL_BINDIR}"
         COMPONENT hmaptool)
 
 add_custom_target(hmaptool ALL DEPENDS ${Depends})

compiler-rt/cmake/base-config-ix.cmake

@@ -5,6 +5,7 @@
 
 include(CheckIncludeFile)
 include(CheckCXXSourceCompiles)
+include(GNUInstallDirs)
 include(ExtendPath)
 
 check_include_file(unwind.h HAVE_UNWIND_H)
@@ -108,13 +109,13 @@ else(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(COMPILER_RT_INSTALL_LIBRARY_DIR "${default_install_path}" CACHE PATH
     "Path where built compiler-rt libraries should be installed.")
 endif()
-extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" bin)
+extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_BINDIR}")
 set(COMPILER_RT_INSTALL_BINARY_DIR "${default_install_path}" CACHE PATH
   "Path where built compiler-rt executables should be installed.")
-extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" include)
+extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_INCLUDEDIR}")
 set(COMPILER_RT_INSTALL_INCLUDE_DIR "${default_install_path}" CACHE PATH
   "Path where compiler-rt headers should be installed.")
-extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" share)
+extend_path(default_install_path "${COMPILER_RT_INSTALL_PATH}" "${CMAKE_INSTALL_DATADIR}")
 set(COMPILER_RT_INSTALL_DATA_DIR "${default_install_path}" CACHE PATH
   "Path where compiler-rt data files should be installed.")
 

libc/CMakeLists.txt

@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 # Use old version of target_sources command which converts the source
 # file paths to full paths.
 cmake_policy(SET CMP0076 OLD)

libcxx/CMakeLists.txt

@@ -10,6 +10,8 @@ endif()
 #===============================================================================
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 
 # Add path for custom modules
@@ -412,9 +414,9 @@ endif ()
 # TODO: Projects that depend on libc++ should use LIBCXX_GENERATED_INCLUDE_DIR
 # instead of hard-coding include/c++/v1.
 
-set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
+set(LIBCXX_INSTALL_INCLUDE_DIR "${CMAKE_INSTALL_INCLUDEDIR}/c++/v1" CACHE PATH
     "Path where target-agnostic libc++ headers should be installed.")
-set(LIBCXX_INSTALL_RUNTIME_DIR bin CACHE PATH
+set(LIBCXX_INSTALL_RUNTIME_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path where built libc++ runtime libraries should be installed.")
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
@@ -423,7 +425,7 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
   set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
       "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1" CACHE PATH
+  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${CMAKE_INSTALL_INCLUDEDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1" CACHE PATH
       "Path where target-specific libc++ headers should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})

libcxx/cmake/Modules/HandleLibCXXABI.cmake

@@ -1,8 +1,9 @@
-
 #===============================================================================
 # Add an ABI library if appropriate
 #===============================================================================
 
+include(GNUInstallDirs)
+
 #
 # _setup_abi: Set up the build to use an ABI library
 #
@@ -63,7 +64,7 @@ macro(setup_abi_lib abidefines abishared abistatic abifiles abidirs)
 
         if (LIBCXX_INSTALL_HEADERS)
           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
-            DESTINATION include/c++/v1/${dstdir}
+            DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}"
             COMPONENT cxx-headers
             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
             )

libcxxabi/CMakeLists.txt

@@ -10,6 +10,8 @@ endif()
 
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 
 # Add path for custom modules
@@ -210,7 +212,7 @@ set(CMAKE_MODULE_PATH
   ${CMAKE_MODULE_PATH}
   )
 
-set(LIBCXXABI_INSTALL_RUNTIME_DIR bin CACHE PATH
+set(LIBCXXABI_INSTALL_RUNTIME_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path where built libc++abi runtime libraries should be installed.")
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)

libunwind/CMakeLists.txt

@@ -8,6 +8,8 @@ endif()
 
 cmake_minimum_required(VERSION 3.13.4)
 
+include(GNUInstallDirs)
+
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 
 # Add path for custom modules
@@ -137,9 +139,9 @@ set(CMAKE_MODULE_PATH
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
     ${CMAKE_MODULE_PATH})
 
-set(LIBUNWIND_INSTALL_INCLUDE_DIR include CACHE PATH
+set(LIBUNWIND_INSTALL_INCLUDE_DIR "${CMAKE_INSTALL_INCLUDEDIR}" CACHE PATH
     "Path where built libunwind headers should be installed.")
-set(LIBUNWIND_INSTALL_RUNTIME_DIR bin CACHE PATH
+set(LIBUNWIND_INSTALL_RUNTIME_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path where built libunwind runtime libraries should be installed.")
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)

llvm/cmake/modules/LLVMInstallSymlink.cmake

@@ -6,7 +6,8 @@ include(GNUInstallDirs)
 
 function(install_symlink name target outdir)
   set(DESTDIR $ENV{DESTDIR})
-  set(bindir "${DESTDIR}${CMAKE_INSTALL_PREFIX}/${outdir}")
+  GNUInstallDirs_get_absolute_install_dir(bindir "${outdir}" BINDIR)
+  set(bindir "${DESTDIR}${bindir}")
 
   message(STATUS "Creating ${name}")