[BUILD] Fix build when LLVM_LIBRARY_DIR is not set (triton-lang#1128)

1. try to search llvm-config up to llvm-config-17 version
2. LLVM_LIBRARY_DIR is expected by MLIR_DIR, so set it to
LLVM_LIBRARY_DIRS, which is outputted by FindLLVM

Co-authored-by: Philippe Tillet <[email protected]>

CMakeLists.txt

@@ -72,6 +72,8 @@ if (NOT MLIR_DIR)
       find_package(LLVM 11 REQUIRED COMPONENTS "nvptx;amdgpu")
     endif()
     message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
+    # FindLLVM outputs LLVM_LIBRARY_DIRS but we expect LLVM_LIBRARY_DIR here
+    set(LLVM_LIBRARY_DIR ${LLVM_LIBRARY_DIRS})
     if(APPLE)
       set(CMAKE_OSX_DEPLOYMENT_TARGET "10.14")
     endif()

cmake/FindLLVM.cmake

@@ -33,14 +33,12 @@
 # We also want an user-specified LLVM_ROOT_DIR to take precedence over the
 # system default locations such as /usr/local/bin. Executing find_program()
 # multiples times is the approach recommended in the docs.
-set(llvm_config_names llvm-config-12.0 llvm-config120 llvm-config-12 llvm-config-12-64
-                      llvm-config-11.0 llvm-config110 llvm-config-11 llvm-config-11-64
-                      llvm-config-10.0 llvm-config100 llvm-config-10 llvm-config-10-64
-                      llvm-config-9.0 llvm-config90 llvm-config-9 llvm-config-9-64
-                      llvm-config-8.0 llvm-config80 llvm-config-8 llvm-config-8-64
-                      llvm-config-7.0 llvm-config70 llvm-config-7 llvm-config-7-64
-                      llvm-config-6.0 llvm-config60
+set(llvm_config_names llvm-config-6.0 llvm-config60
                       llvm-config)
+foreach(v RANGE 7 17)
+    # names like llvm-config-7.0 llvm-config70 llvm-config-7 llvm-config-7-64
+    list(PREPEND llvm_config_names llvm-config-${v}.0 llvm-config${v}0 llvm-config-${v} llvm-config-${v}-64)
+endforeach()
 find_program(LLVM_CONFIG
     NAMES ${llvm_config_names}
     PATHS ${LLVM_ROOT_DIR}/bin NO_DEFAULT_PATH