fix: ggml: fix vulkan-shaders-gen build (ggml-org#10448)

* fix: ggml: fix vulkan-shaders-gen build

The vulkan-shaders-gen target was not being built correctly
in case of cross-compilation.
Other outputs need to be built for the cross compile target,
but vulkan-shaders-gen needs to be built for the host.

* refactor: ggml: Improve vulkan-shaders-gen toolchain setup

- Add GGML_SHADERS_GEN_TOOLCHAIN CMake option.
- Auto-detect host toolchain if not set.

* refactor: ggml: Improve vulkan-shaders-gen toolchain setup

Use configure_file to generate host_toolchain.cmake from template

* fix: ggml: Fix compile error

Fix compile error not finding vulkan-shaders-gen

* fix: vulkan-shaders-gen build and path handling

Fix build issues with vulkan-shaders-gen:
- Add target dependency for correct build order
- Use CMAKE_HOST_SYSTEM_NAME for executable suffix
- Fix MSVC output directory in host toolchain
- Normalize path handling for cross-compilation

* fix: improve host compiler detection in vulkan shader build

Improve host compiler detection for vulkan shader generation:
- Add NO_CMAKE_FIND_ROOT_PATH to all compiler searches
- Consolidate compiler detection logic
- Fix Windows-specific MSVC detection
- Ensure correct compiler search in cross-compilation

* refactor: Simplify CMake function for detecting host compiler

Simplified the CMake function to improve the process of detecting the host compiler.

* fix: Remove unnecessary Vulkan library linkage in CMakeLists.txt

Since `vulkan-shader-gen.cpp` only requires the `glslc` executable
and not the Vulkan headers or libraries, CMakeLists.txt needs to
be corrected.
(See: ecc93d0)

* refactor: Rename host_toolchain.cmake.in

- Rename host_toolchain.cmake.in to cmake/host-toolchain.cmake.in

* refactor: GGML_VULKAN_SHADERS_GEN_TOOLCHAIN

Rename the macro GGML_SHADERS_GEN_TOOLCHAIN to GGML_VULKAN_SHADERS_GEN_TOOLCHAIN

Author: sparkleholic

ggml/CMakeLists.txt

@@ -185,6 +185,9 @@ option(GGML_OPENCL_PROFILING                "ggml: use OpenCL profiling (increas
 option(GGML_OPENCL_EMBED_KERNELS            "ggml: embed kernels"                             ON)
 option(GGML_OPENCL_USE_ADRENO_KERNELS       "ggml: use optimized kernels for Adreno"          ON)
 
+# toolchain for vulkan-shaders-gen
+set   (GGML_VULKAN_SHADERS_GEN_TOOLCHAIN "" CACHE FILEPATH "ggml: toolchain file for vulkan-shaders-gen")
+
 # extra artifacts
 option(GGML_BUILD_TESTS    "ggml: build tests"    ${GGML_STANDALONE})
 option(GGML_BUILD_EXAMPLES "ggml: build examples" ${GGML_STANDALONE})

ggml/src/ggml-vulkan/CMakeLists.txt

@@ -1,5 +1,20 @@
+cmake_minimum_required(VERSION 3.19)
+cmake_policy(SET CMP0114 NEW)
+
 find_package(Vulkan COMPONENTS glslc REQUIRED)
 
+function(detect_host_compiler)
+    if (CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+        find_program(HOST_C_COMPILER NAMES cl gcc clang NO_CMAKE_FIND_ROOT_PATH)
+        find_program(HOST_CXX_COMPILER NAMES cl g++ clang++ NO_CMAKE_FIND_ROOT_PATH)
+    else()
+        find_program(HOST_C_COMPILER NAMES gcc clang NO_CMAKE_FIND_ROOT_PATH)
+        find_program(HOST_CXX_COMPILER NAMES g++ clang++ NO_CMAKE_FIND_ROOT_PATH)
+    endif()
+    set(HOST_C_COMPILER "${HOST_C_COMPILER}" PARENT_SCOPE)
+    set(HOST_CXX_COMPILER "${HOST_CXX_COMPILER}" PARENT_SCOPE)
+endfunction()
+
 if (Vulkan_FOUND)
     message(STATUS "Vulkan found")
 
@@ -73,19 +88,56 @@ if (Vulkan_FOUND)
         add_compile_definitions(GGML_VULKAN_RUN_TESTS)
     endif()
 
-    add_subdirectory(vulkan-shaders)
-
-    set (_ggml_vk_genshaders_cmd vulkan-shaders-gen)
+    if (NOT CMAKE_CROSSCOMPILING)
+        add_subdirectory(vulkan-shaders)
+        if (MSVC)
+            foreach(CONFIG ${CMAKE_CONFIGURATION_TYPES})
+                string(TOUPPER ${CONFIG} CONFIG)
+                set_target_properties(vulkan-shaders-gen PROPERTIES
+                    RUNTIME_OUTPUT_DIRECTORY_${CONFIG} ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
+            endforeach()
+        endif()
+    else()
+        if (GGML_VULKAN_SHADERS_GEN_TOOLCHAIN)
+            set(HOST_CMAKE_TOOLCHAIN_FILE ${GGML_VULKAN_SHADERS_GEN_TOOLCHAIN})
+        else()
+            detect_host_compiler()
+            if (NOT HOST_C_COMPILER OR NOT HOST_CXX_COMPILER)
+                message(FATAL_ERROR "Host compiler not found")
+            else()
+                message(STATUS "Host compiler: ${HOST_C_COMPILER} ${HOST_CXX_COMPILER}")
+            endif()
+            configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/host-toolchain.cmake.in ${CMAKE_BINARY_DIR}/host-toolchain.cmake @ONLY)
+            set(HOST_CMAKE_TOOLCHAIN_FILE ${CMAKE_BINARY_DIR}/host-toolchain.cmake)
+        endif()
+        message(STATUS "vulkan-shaders-gen toolchain file: ${HOST_CMAKE_TOOLCHAIN_FILE}")
+
+        include(ExternalProject)
+        # Native build through ExternalProject_Add
+        ExternalProject_Add(
+            vulkan-shaders-gen
+            SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/vulkan-shaders
+            CMAKE_ARGS -DCMAKE_TOOLCHAIN_FILE=${HOST_CMAKE_TOOLCHAIN_FILE}
+                    -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}
+            BUILD_COMMAND ${CMAKE_COMMAND} --build .
+            INSTALL_COMMAND ${CMAKE_COMMAND} --install .
+            INSTALL_DIR ${CMAKE_BINARY_DIR}
+        )
+        ExternalProject_Add_StepTargets(vulkan-shaders-gen build install)
+    endif()
+    set (_ggml_vk_host_suffix $<IF:$<STREQUAL:${CMAKE_HOST_SYSTEM_NAME},Windows>,.exe,>)
+    set (_ggml_vk_genshaders_cmd ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/vulkan-shaders-gen${_ggml_vk_host_suffix})
     set (_ggml_vk_header     ${CMAKE_CURRENT_BINARY_DIR}/ggml-vulkan-shaders.hpp)
     set (_ggml_vk_source     ${CMAKE_CURRENT_BINARY_DIR}/ggml-vulkan-shaders.cpp)
     set (_ggml_vk_input_dir  ${CMAKE_CURRENT_SOURCE_DIR}/vulkan-shaders)
     set (_ggml_vk_output_dir ${CMAKE_CURRENT_BINARY_DIR}/vulkan-shaders.spv)
 
     file(GLOB _ggml_vk_shader_deps "${_ggml_vk_input_dir}/*.comp")
+    set (_ggml_vk_shader_deps ${_ggml_vk_shader_deps} vulkan-shaders-gen)
 
-    if (NOT CMAKE_CROSSCOMPILING)
-        set(_ggml_vk_genshaders_cmd "$<TARGET_FILE_DIR:vulkan-shaders-gen>/${_ggml_vk_genshaders_cmd}")
-    endif ()
+    if (CMAKE_CROSSCOMPILING)
+        set(_ggml_vk_shader_deps ${_ggml_vk_shader_deps} vulkan-shaders-gen-build vulkan-shaders-gen-install)
+    endif()
 
     add_custom_command(
         OUTPUT ${_ggml_vk_header}
@@ -99,7 +151,7 @@ if (Vulkan_FOUND)
             --target-cpp ${_ggml_vk_source}
             --no-clean
 
-        DEPENDS ${_ggml_vk_shader_deps} ${_ggml_vk_genshaders_cmd}
+        DEPENDS ${_ggml_vk_shader_deps}
         COMMENT "Generate vulkan shaders"
     )
 

ggml/src/ggml-vulkan/cmake/host-toolchain.cmake.in

@@ -0,0 +1,15 @@
+set(CMAKE_BUILD_TYPE Release)
+set(CMAKE_C_FLAGS -O2)
+set(CMAKE_CXX_FLAGS -O2)
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE NEVER)
+set(CMAKE_C_COMPILER @HOST_C_COMPILER@)
+set(CMAKE_CXX_COMPILER @HOST_CXX_COMPILER@)
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY @CMAKE_RUNTIME_OUTPUT_DIRECTORY@)
+
+if("@CMAKE_C_COMPILER_ID@" STREQUAL "MSVC")
+    foreach(CONFIG IN ITEMS DEBUG RELEASE MINSIZEREL RELWITHDEBINFO)
+        set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_${CONFIG} ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
+    endforeach()
+endif()

ggml/src/ggml-vulkan/vulkan-shaders/CMakeLists.txt

@@ -1,9 +1,11 @@
 find_package (Threads REQUIRED)
-find_package(Vulkan COMPONENTS glslc REQUIRED)
+find_program(GLSLC_EXECUTABLE glslc)
+if(NOT GLSLC_EXECUTABLE)
+    message(FATAL_ERROR "glslc not found.")
+endif()
 
 set(TARGET vulkan-shaders-gen)
 add_executable(${TARGET} vulkan-shaders-gen.cpp)
 install(TARGETS ${TARGET} RUNTIME)
 target_compile_features(${TARGET} PRIVATE cxx_std_17)
 target_link_libraries(vulkan-shaders-gen PUBLIC Threads::Threads)
-target_link_libraries(vulkan-shaders-gen PRIVATE Vulkan::Vulkan)

ggml/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp

@@ -30,8 +30,6 @@
     #include <fcntl.h>
 #endif
 
-#include <vulkan/vulkan_core.h>
-
 #define ASYNCIO_CONCURRENCY 64
 
 std::mutex lock;