[CK_BUILDER] Add experimental builder directory and configuration for composable_kernel (#3043)

Add experimental builder infrastructure for composable_kernel

- Add experimental/builder directory with README documentation.
- Create initial test infrastructure with CMakeLists.txt and placeholder test.
- Update root CMakeLists.txt to support CK_EXPERIMENTAL_BUILDER option.
- Update .gitignore to not treat `experimental/builder` as a CMake build directory.

This establishes the directory structure  for a high-level builder pattern that will provide a semantically-clear interface for constructing CK operations, with initial focus on convolution kernels for MIOpen integration.


[ROCm/composable_kernel commit: f18b79f328]

.gitignore

@@ -36,7 +36,7 @@ tags
 # Editors
 .vscode
 
-# build-in-source directory
+# build-in-source directory (see exceptions below)
 build*
 
 # emacs temporary/backup files
@@ -58,7 +58,7 @@ _doxygen/
 docs/doxygen/html
 docs/doxygen/xml
 
-# JetBrains IDE
+# JetBrains IDE (see build* exceptions below)
 .idea/
 cmake-build*/
 build*/
@@ -71,3 +71,7 @@ __pycache__/
 
 .cache/
 
+# Exceptions to build* patterns above
+# The experimental/builder directory should be tracked despite matching build*
+!experimental/builder
+!experimental/builder/**

CMakeLists.txt

@@ -37,6 +37,7 @@ include(CTest)
 
 option(ENABLE_CLANG_CPP_CHECKS "Enables clang tidy, cppcheck" ON)
 option(MIOPEN_REQ_LIBS_ONLY "Build only the MIOpen required libraries" OFF)
+option(CK_EXPERIMENTAL_BUILDER "Enable experimental builder" OFF)
 option(BUILD_MHA_LIB "Build the static library for flash attention" OFF)
 
 # Usage: for customized Python location cmake -DCK_USE_ALTERNATIVE_PYTHON="/opt/Python-3.8.13/bin/python3.8"
@@ -692,6 +693,10 @@ if (NOT MIOPEN_REQ_LIBS_ONLY)
     add_subdirectory(profiler)
 endif()
 
+if (CK_EXPERIMENTAL_BUILDER)
+  add_subdirectory(experimental/builder)
+endif()
+
 if(CK_USE_CODEGEN AND (SUPPORTED_GPU_TARGETS MATCHES "gfx9" OR GPU_ARCHS))
   add_subdirectory(codegen)
 endif()

cmake/gtest.cmake

@@ -1,3 +1,4 @@
+include_guard(GLOBAL)
 include(FetchContent)
 
 set(GOOGLETEST_DIR "" CACHE STRING "Location of local GoogleTest repo to build against")

experimental/builder/CMakeLists.txt

@@ -0,0 +1,3 @@
+if(BUILD_TESTING)
+    add_subdirectory(test)
+endif()

experimental/builder/README.md

@@ -0,0 +1,34 @@
+# Builder
+
+This directory contains the experimental builder feature for composable_kernel.
+
+* Status: In development (October - November 2025)
+
+## Overview
+
+The builder provides a high-level, semantically-clear interface for constructing composable kernel operations, with an initial focus on convolution kernels for MIOpen. It leverages modern C++20 features (such as POD structs as non-type template parameters, concepts, and designated initializers) to simplify kernel instantiation and improve developer experience.
+
+This project is a prototype for a more general builder pattern for all of composable_kernel (CK) and CKTile, but is currently limited to formalizing the interface between MIOpen and CK.
+
+## Directory Structure
+
+- `include/ck_tile/builder/`  
+  Core builder headers and public API.
+- `test/`  
+  Unit tests and example usage of the builder pattern.
+- `CMakeLists.txt`  
+  CMake configuration for building the experimental builder and its tests.
+
+## CMake Configuration
+
+To enable the experimental builder, configure your build with:
+
+```sh
+cmake -DCK_EXPERIMENTAL_BUILDER=ON -DCMAKE_CXX_STANDARD=20 ...
+```
+## Building and testing
+
+During development, build and test from the CK build directory with
+```sh
+ninja test_conv_builder && bin/test_conv_builder
+```

experimental/builder/include/ck_tile/builder/CMakeLists.txt

@@ -0,0 +1 @@
+# Empty placeholder until we add library code.

experimental/builder/test/CMakeLists.txt

@@ -0,0 +1,20 @@
+
+include(gtest)
+
+# Helper function to create a gtest executable with common properties
+function(add_ck_builder_test test_name)
+    add_executable(${test_name} ${ARGN})
+    target_compile_features(${test_name} PRIVATE cxx_std_20)
+    target_include_directories(${test_name} PRIVATE
+        "${PROJECT_SOURCE_DIR}/experimental/builder/include"
+        "${PROJECT_SOURCE_DIR}/include"
+    )
+    target_compile_options(${test_name} PRIVATE
+        -Wno-global-constructors
+        -Wno-c++20-compat
+    )
+    target_link_libraries(${test_name} PRIVATE GTest::gtest_main GTest::gmock)
+endfunction()
+
+add_ck_builder_test(test_conv_builder
+    test_conv_builder.cpp)

experimental/builder/test/test_conv_builder.cpp

@@ -0,0 +1,11 @@
+#include <gtest/gtest.h>
+
+class ConvBuilderTest : public ::testing::Test
+{
+};
+
+TEST_F(ConvBuilderTest, PlaceholderTest)
+{
+    // TODO: Implement actual test
+    EXPECT_TRUE(true);
+}