LiteRT CMake Build Instructions

Use this guide to configure and build the LiteRT runtime with CMake on macOS The instructions cover both Android cross-compilation targets (using macOS and Linux as host machine) and native macOS and Linux builds.

Common Build Steps

Install CMake 4.0.1 from: https://github.com/kitware/cmake/releases

All build presets expect you to work from the repository root:

  cd 
  
./litert 

The generated build trees live under cmake_build* . Parallel builds can be controlled via -j with the desired core count.

Available Build Flavors

LiteRT supports both Releaseand Debugbuild flavors:

Releasebuilds use -O3 -DNDEBUG for optimized production binaries. Debugbuilds use -O0 -g for debugging with full symbol information.

Android (arm64) Cross-Compilation

1. Install the Android NDK and export the path so CMake can find it:

     export 
     
    ANDROID_NDK_HOME 
    = 
   /absolute/path/to/android-ndk-r27 
   

2. Configure host-side flatbuffer tools

    cmake  
   --preset  
   android-arm64 ; 
    
   

3. Configure the LiteRT Android build using the provided preset and point to the generated FlatBuffers tools:

     # For Release build: 
   cmake  
   --preset  
   android-arm64  
    \ 
     
   -DTFLITE_HOST_TOOLS_DIR = 
    " 
    $( 
    cd 
     
   ../host_flatc_build/_deps/flatbuffers-build && 
    pwd 
    ) 
    " 
    # For Debug build: 
   cmake  
   --preset  
   android-arm64-debug  
    \ 
     
   -DTFLITE_HOST_TOOLS_DIR = 
    " 
    $( 
    cd 
     
   ../host_flatc_build/_deps/flatbuffers-build && 
    pwd 
    ) 
    " 
    
   

4. Build LiteRT for Android:

     # For Release build: 
   cmake  
   --build  
   cmake_build_android_arm64  
   -j # For Debug build: 
   cmake  
   --build  
   cmake_build_android_arm64_debug  
   -j 
   

Artifacts such as static libraries will be emitted under the corresponding build directory ( cmake_build_android_arm64 or cmake_build_android_arm64_debug ).

Desktop Build from macOS and Linux

1. Configure the default preset for Desktop builds:

     # For Release build: 
   cmake  
   --preset  
   default # For Debug build: 
   cmake  
   --preset  
   default-debug 
   

2. Build LiteRT:

     # For Release build: 
   cmake  
   --build  
   cmake_build  
   -j # For Debug build: 
   cmake  
   --build  
   cmake_build_debug  
   -j 
   

Customize your build target

Customizing CMake Builds

Use CMake options to control which toolchains and features are compiled into your targets. E.g.:

 cmake  
-S  
.  
-B  
build-release  
 \ 
  
-DCMAKE_BUILD_TYPE = 
Release  
 \ 
  
-DLITERT_AUTO_BUILD_TFLITE = 
ON  
 \ 
  
-DLITERT_ENABLE_GPU = 
OFF  
 \ 
  
-DLITERT_ENABLE_NPU = 
OFF  
 \ 
  
-DLITERT_DISABLE_KLEIDIAI = 
ON  
 \ 
  
-DLITERT_HOST_C_COMPILER = 
/usr/bin/clang  
 \ 
  
-DLITERT_HOST_CXX_COMPILER = 
/usr/bin/clang++
cmake  
--build  
build-release  
--target  
dispatch_api_Qualcomm_so  
-j8 

• LITERT_HOST_C_COMPILER / LITERT_HOST_CXX_COMPILER let you point the helper host tools at any Clang/GCC installation without editing CMakeLists.txt .
• LITERT_DISABLE_KLEIDIAI keeps x86 desktop builds reproducible by skipping KleidiAI; set it to OFF whenever you want to bundle the delegate.
• Always pass -DCMAKE_BUILD_TYPE=Release (or the equivalent preset) when you need the optimized artifact. This makes CMake use -O3 -DNDEBUG for you.

Producing Minimum-Size Vendor Libraries

At link time enable dead-stripping so dispatch libraries match Bazel’s size:

• macOS: add -DCMAKE_SHARED_LINKER_FLAGS_RELEASE="-Wl,-dead_strip -dead_strip_dylibs" (and the same for CMAKE_EXE_LINKER_FLAGS_RELEASE if you want the executeables stripped). After building, run strip -x path/to/libLiteRtDispatch_Qualcomm.dylib .
• Linux: add -DCMAKE_SHARED_LINKER_FLAGS_RELEASE="-Wl,--gc-sections" and run strip --strip-unneeded path/to/libLiteRtDispatch_Qualcomm.so (or make it a POST_BUILD command).

These flags can live directly in cmake --preset … entries in CMakePresets.json so every developer in your team gets the same configuration.

Troubleshooting Tips

• Delete the corresponding cmake_build* directory if you change toolchains or major configuration options, then rerun the configure step.
• Inspect CMakeCache.txt inside each build tree for resolved dependency paths.