Add CMake build rules for (some) of the generator jit tests

cmake/HalideGeneratorHelpers.cmake

@@ -92,9 +92,15 @@ function(add_halide_generator TARGET)
 
             # TODO: what do we need to do for PACKAGE_NAME PACKAGE_NAMESPACE EXPORT_FILE in this case?
         else ()
-            add_executable(${TARGET} ${ARG_SOURCES})
+            # Make a library of the Generator that can be used for (e.g.) cpp_stub.
+            add_library("${TARGET}_lib" OBJECT ${ARG_SOURCES})
+            target_link_libraries("${TARGET}_lib" PRIVATE Halide::Halide ${ARG_LINK_LIBRARIES})
+            target_include_directories("${TARGET}_lib" INTERFACE "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>")
+
+            add_executable(${TARGET} "$<TARGET_OBJECTS:${TARGET}_lib>")
+            target_link_libraries("${TARGET}" PRIVATE Halide::Generator)
+
             add_executable(${gen} ALIAS ${TARGET})
-            target_link_libraries(${TARGET} PRIVATE Halide::Generator ${ARG_LINK_LIBRARIES})
 
             if (NOT ARG_NO_DEFAULT_FLAGS AND NOT Halide_NO_DEFAULT_FLAGS)
                 # For crosscompiling builds, the Halide headers will be included using -isystem,
@@ -182,11 +188,11 @@ function(add_halide_library TARGET)
     # - `c_source` is selected by C_BACKEND
     # - `object` is selected for CMake-target-compile
     # - `static_library` is selected for cross-compile
-    # - `cpp_stub` is not available
     set(extra_output_names
         ASSEMBLY
         BITCODE
         COMPILER_LOG
+        CPP_STUB
         FEATURIZATION
         FUNCTION_INFO_HEADER
         LLVM_ASSEMBLY
@@ -201,6 +207,7 @@ function(add_halide_library TARGET)
     set(ASSEMBLY_extension ".s")
     set(BITCODE_extension ".bc")
     set(COMPILER_LOG_extension ".halide_compiler_log")
+    set(CPP_STUB_extension ".stub.h")
     set(FEATURIZATION_extension ".featurization")
     set(FUNCTION_INFO_HEADER_extension ".function_info.h")
     set(LLVM_ASSEMBLY_extension ".ll")

src/Generator.cpp

@@ -1605,6 +1605,7 @@ bool GeneratorBase::emit_cpp_stub(const std::string &stub_file_path) {
     GeneratorParamInfo &pi = param_info();
     std::ofstream file(stub_file_path);
     StubEmitter emit(file, generator_registered_name, generator_stub_name, pi.generator_params(), pi.inputs(), pi.outputs());
+    debug(1) << "GeneratorBase::emit_cpp_stub(): generating cpp_stub at " << stub_file_path << "\n";
     emit.emit();
     return true;
 }

test/generator/CMakeLists.txt

@@ -64,6 +64,7 @@ function(_add_halide_libraries TARGET)
                        FEATURES "${args_FEATURES}"
                        PARAMS "${args_PARAMS}"
                        PLUGINS "${args_PLUGINS}"
+                       CPP_STUB cpp_stub_out
                        FUNCTION_INFO_HEADER function_info_header_out)
     if (args_EXTERNS)
         target_link_libraries(${TARGET} INTERFACE ${args_EXTERNS})
@@ -225,12 +226,6 @@ endif ()
 _add_halide_libraries(acquire_release)
 _add_halide_aot_tests(acquire_release)
 
-# TODO: what are these?
-# configure_jittest.cpp
-# example_jittest.cpp
-# registration_test.cpp
-# rungen_test.cpp
-
 # alias_aottest.cpp
 # alias_generator.cpp
 set(EXTRA_ALIAS_LIBS alias_with_offset_42 alias_Adams2019 alias_Li2018 alias_Mullapudi2016)
@@ -606,3 +601,49 @@ _add_halide_aot_tests(variable_num_threads
                       # Requires threading support, not yet available for wasm tests
                       ENABLE_IF NOT ${_USING_WASM}
                       GROUPS multithreaded)
+
+
+##
+# Create targets for the JIT tests
+##
+
+if (TARGET_WEBASSEMBLY AND Halide_TARGET MATCHES "wasm_threads")
+    message(STATUS "Skipping Generator JIT tests under wasm_webgpu")
+    return()
+endif ()
+
+if (TARGET_WEBASSEMBLY AND Halide_TARGET MATCHES "wasm_webgpu")
+    message(STATUS "Skipping Generator JIT tests under wasm_webgpu")
+    return()
+endif ()
+
+function(_add_halide_jit_test NAME)
+    set(options "")
+    set(oneValueArgs "")
+    set(multiValueArgs GROUPS)
+    cmake_parse_arguments(args "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    set(TARGET "generator_jit_${NAME}")
+    set(SRCS "${NAME}_jittest.cpp")
+
+    add_executable("${TARGET}" "${SRCS}")
+    target_link_libraries("${TARGET}" PRIVATE "${NAME}.generator_lib" Halide::Test Halide::TerminateHandler)
+
+    # Some of the jit tests require the cpp_stub file from the Generator, so ensure it's built first:
+    add_dependencies("${TARGET}" "${NAME}")
+
+    add_halide_test(${TARGET} GROUPS generator ${args_GROUPS})
+
+endfunction()
+
+# configure_jittest.cpp
+# configure_generator.cpp
+_add_halide_jit_test(configure)
+
+# example_jittest.cpp
+# example_generator.cpp
+_add_halide_jit_test(example GROUPS multithreaded)
+
+# TODO:
+# registration_test.cpp
+# rungen_test.cpp