[SYCL][CMake] Simplify emhash fetch code (intel#19894)

Upstream added a CMake install target, so now we can rely on that when
using a system installed version, and we can create an interface target
to emulate the real one when using FetchContent.

The upstream CMake install target installs all files directly in the
given prefix folder, so with `CMAKE_PREFIX_PATH=/usr` it will install
`hash_table8.hpp` directly to `/usr`, not in an `emhash` subfolder.

Since it seems that's how upstream wants this packaged, update our
includes to remove the fake `emhash` subdirectory.

Issue: intel#19635

---------

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

sycl/cmake/modules/AddSYCLUnitTest.cmake

@@ -121,6 +121,7 @@ function(add_sycl_unittest_internal test_dirname link_variant is_preview)
       mockOpenCL
       LLVMTestingSupport
       OpenCL-Headers
+      emhash::emhash
       unified-runtime::mock
       ${SYCL_LINK_LIBS}
     )

sycl/cmake/modules/BuildUnifiedRuntime.cmake

@@ -216,7 +216,6 @@ if(CMAKE_SYSTEM_NAME STREQUAL Windows)
       -DUMF_BUILD_SHARED_LIBRARY:BOOL=${UMF_BUILD_SHARED_LIBRARY}
       -DUMF_LINK_HWLOC_STATICALLY:BOOL=${UMF_LINK_HWLOC_STATICALLY}
       -DUMF_DISABLE_HWLOC:BOOL=${UMF_DISABLE_HWLOC}
-      -DSYCL_EMHASH_DIR:STRING=${SYCL_EMHASH_DIR}
       # Enable d suffix in UMF
       -DUMF_USE_DEBUG_POSTFIX:BOOL=ON
   )

sycl/cmake/modules/FetchEmhash.cmake

@@ -1,25 +1,22 @@
 # Finds or fetches emhash.
-if(DEFINED SYCL_EMHASH_DIR OR DEFINED EMHASH_SYS_LOC)
+if(TARGET emhash::emhash)
   return()
 endif()
-find_file(EMHASH_SYS_LOC "hash_table8.hpp" PATH_SUFFIXES "emhash")
-if(NOT EMHASH_SYS_LOC)
+find_package(emhash QUIET)
+if(NOT emhash_FOUND)
   set(EMHASH_REPO https://github.com/ktprime/emhash)
   message(STATUS "Will fetch emhash from ${EMHASH_REPO}")
   include(FetchContent)
   FetchContent_Declare(emhash
     GIT_REPOSITORY    ${EMHASH_REPO}
-    GIT_TAG           3ba9abdfdc2e0430fcc2fd8993cad31945b6a02b
+    GIT_TAG           09fb0439de0c65e387498232c89d561ee95fbd60
     SOURCE_SUBDIR  emhash
   )
   FetchContent_MakeAvailable(emhash)
 
-  # FetchContent downloads the files into a directory with
-  # '-src' as the suffix and emhash has the headers in the
-  # top level directory in the repo, so copy the headers to a directory
-  # named `emhash` so source files can include with <emhash/header.hpp>
-  file(MAKE_DIRECTORY ${CMAKE_BINARY_DIR}/include/emhash)
-  file(GLOB HEADERS "${emhash_SOURCE_DIR}/*.h*")
-  file(COPY ${HEADERS} DESTINATION ${CMAKE_BINARY_DIR}/include/emhash)
-  set(SYCL_EMHASH_DIR ${CMAKE_BINARY_DIR}/include/ CACHE INTERNAL "")
+  # The official cmake install target uses the 'emhash' namespace,
+  # so emulate that here so client code can use a single target name for both cases.
+  add_library(emhash INTERFACE)
+  target_include_directories(emhash SYSTEM INTERFACE ${emhash_SOURCE_DIR})
+  add_library(emhash::emhash ALIAS emhash)
 endif()

sycl/source/CMakeLists.txt

@@ -147,14 +147,7 @@ function(add_sycl_rt_library LIB_NAME LIB_OBJ_NAME)
     target_include_directories(${LIB_OBJ_NAME} PRIVATE ${zstd_INCLUDE_DIR})
   endif()
 
-  if (EMHASH_SYS_LOC)
-    # If we are using system emhash, include the system directory
-    # containing the emhash folder and note this location so
-    # other modules using emhash can find it.
-    cmake_path(GET EMHASH_SYS_LOC PARENT_PATH EMHASH_SYS_LOC)
-    set(SYCL_EMHASH_DIR ${EMHASH_SYS_LOC} CACHE INTERNAL "")
-    target_include_directories(${LIB_OBJ_NAME} PRIVATE ${EMHASH_SYS_LOC})
-  endif()
+  target_link_libraries(${LIB_OBJ_NAME} PRIVATE emhash::emhash)
 
   # ur_win_proxy_loader
   if (WIN32)

sycl/source/detail/device_kernel_info.hpp

@@ -9,7 +9,7 @@
 
 #include <detail/hashers.hpp>
 #include <detail/kernel_arg_mask.hpp>
-#include <emhash/hash_table8.hpp>
+#include <hash_table8.hpp>
 #include <sycl/detail/compile_time_kernel_info.hpp>
 #include <sycl/detail/kernel_name_str_t.hpp>
 #include <sycl/detail/spinlock.hpp>

sycl/source/detail/unordered_multimap.hpp

@@ -7,7 +7,7 @@
 //===--------------------------------------------------------------===//
 #pragma once
 #include <detail/hashers.hpp>
-#include <emhash/hash_table8.hpp>
+#include <hash_table8.hpp>
 
 #include <utility>
 #include <vector>

sycl/test/CMakeLists.txt

@@ -20,6 +20,8 @@ if(SYCL_ENABLE_EXTENSION_JIT)
   list(APPEND test_includes ${LLVM_EXTERNAL_SYCL_JIT_SOURCE_DIR}/jit-compiler/include)
   list(APPEND test_includes ${LLVM_EXTERNAL_SYCL_JIT_SOURCE_DIR}/common/include)
 endif(SYCL_ENABLE_EXTENSION_JIT)
+get_target_property(EMHASH_INCLUDES emhash::emhash INTERFACE_INCLUDE_DIRECTORIES)
+list(APPEND test_includes ${EMHASH_INCLUDES})
 list(JOIN test_includes ":" TEST_INCLUDE_PATH)
 
 configure_lit_site_cfg(

xptifw/include/xpti_string_table.hpp

@@ -7,7 +7,7 @@
 
 #include "parallel_hashmap/phmap.h"
 #include "xpti/xpti_data_types.h"
-#include <emhash/hash_table7.hpp>
+#include <hash_table7.hpp>
 
 #include <atomic>
 #include <shared_mutex>

xptifw/src/CMakeLists.txt

@@ -3,7 +3,7 @@ include(FetchContent)
 
 # The sycl target should download or find emhash but may not
 # for standalone builds.
-if (NOT SYCL_EMHASH_DIR)
+if (NOT TARGET emhash::emhash)
   list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/../../sycl/cmake/modules")
   include(FetchEmhash)
 endif()
@@ -37,11 +37,12 @@ function(add_xpti_library LIB_NAME)
   target_compile_definitions(${LIB_NAME} PRIVATE -DXPTI_API_EXPORTS)
   target_include_directories(${LIB_NAME} PUBLIC
     $<BUILD_INTERFACE:${XPTIFW_DIR}/include>
-    $<BUILD_INTERFACE:${SYCL_EMHASH_DIR}>
     $<BUILD_INTERFACE:${XPTIFW_PARALLEL_HASHMAP_HEADERS}>
     $<BUILD_INTERFACE:${XPTI_DIR}/include>
   )
 
+  target_link_libraries(${LIB_NAME} PUBLIC emhash::emhash)
+
   find_package(Threads REQUIRED)
   target_link_libraries(${LIB_NAME} PUBLIC ${CMAKE_DL_LIBS} Threads::Threads)
 

xptifw/src/xpti_trace_framework.cpp

@@ -19,7 +19,7 @@
 #include "xpti_int64_hash_table.hpp"
 #include "xpti_object_table.hpp"
 #include "xpti_string_table.hpp"
-#include <emhash/hash_table7.hpp>
+#include <hash_table7.hpp>
 
 #include <algorithm>
 #include <array>