rust: disable single file header

Rust doesn't need the single file header. In the interest of keeping the
crate size small, I've simply added a flag that disables generation of
the single file header. The single file header still builds by default.

CMakeLists.txt

@@ -148,6 +148,7 @@ option(BUILD_JAVA "Build Java API." FALSE)
 option(BUILD_NODEJS "Build NodeJS API." FALSE)
 option(BUILD_PYTHON "Build Python API." FALSE)
 option(BUILD_SHELL "Build Interactive Shell" TRUE)
+option(BUILD_SINGLE_FILE_HEADER "Build single file header." TRUE)
 option(BUILD_TESTS "Build C++ tests." FALSE)
 
 option(BUILD_LCOV "Build coverage report." FALSE)

src/CMakeLists.txt

@@ -41,16 +41,18 @@ endif()
 
 install(TARGETS kuzu kuzu_shared)
 
-# Create a command to generate kuzu.hpp, and then create a target that is
-# always built that depends on it. This allows our generator to detect when
-# exactly to build kuzu.hpp, while still building the target by default.
-find_package(Python3 3.9...4 REQUIRED)
-add_custom_command(
-        OUTPUT kuzu.hpp
-        COMMAND
-                ${Python3_EXECUTABLE} ${PROJECT_SOURCE_DIR}/scripts/collect-single-file-header.py
-        DEPENDS
-                ${PROJECT_SOURCE_DIR}/scripts/collect-single-file-header.py kuzu_shared)
-add_custom_target(single_file_header ALL DEPENDS kuzu.hpp)
+if(${BUILD_SINGLE_FILE_HEADER})
+        # Create a command to generate kuzu.hpp, and then create a target that is
+        # always built that depends on it. This allows our generator to detect when
+        # exactly to build kuzu.hpp, while still building the target by default.
+        find_package(Python3 3.9...4 REQUIRED)
+        add_custom_command(
+                OUTPUT kuzu.hpp
+                COMMAND
+                        ${Python3_EXECUTABLE} ${PROJECT_SOURCE_DIR}/scripts/collect-single-file-header.py
+                DEPENDS
+                        ${PROJECT_SOURCE_DIR}/scripts/collect-single-file-header.py kuzu_shared)
+        add_custom_target(single_file_header ALL DEPENDS kuzu.hpp)
+endif()
 
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/kuzu.hpp ${CMAKE_CURRENT_SOURCE_DIR}/include/c_api/kuzu.h TYPE INCLUDE)

tools/rust_api/build.rs

@@ -96,7 +96,10 @@ fn build_bundled_cmake() -> Result<Vec<PathBuf>, Box<dyn std::error::Error>> {
     };
 
     let mut build = cmake::Config::new(&kuzu_root);
-    build.no_build_target(true).define("BUILD_SHELL", "OFF");
+    build
+        .no_build_target(true)
+        .define("BUILD_SHELL", "OFF")
+        .define("BUILD_SINGLE_FILE_HEADER", "OFF");
     if cfg!(windows) {
         build.generator("Ninja");
         build.cxxflag("/EHsc");