fail to build QNN backend on macOS

[nirvanagth]

🐛 Describe the bug

I'm following https://github.com/pytorch/executorch/blob/main/examples/demo-apps/android/LlamaDemo/docs/delegates/qualcomm_README.md to build QNN model on my M1 mac. I'm currently stuck at the step to build Build QNN backend with ExecuTorch. there are two errors I encountered.

1. I'm getting

 CMake Error at backends/qualcomm/runtime/backends/CMakeLists.txt:66 (target_sources):
  Cannot find source file:

    /Users/tianhaogu/Documents/executorch/backends/qualcomm/runtime/backends/htpbackend/arm64/HtpContextCustomConfig.cpp

  Tried extensions .c .C .c++ .cc .cpp .cxx .cu .mpp .m .M .mm .ixx .cppm
  .ccm .cxxm .c++m .h .hh .h++ .hm .hpp .hxx .in .txx .f .F .for .f77 .f90
  .f95 .f03 .hip .ispc

when I build

cmake -DPYTHON_EXECUTABLE=python \
    -DCMAKE_INSTALL_PREFIX=cmake-out \
    -DEXECUTORCH_ENABLE_LOGGING=1 \
    -DCMAKE_BUILD_TYPE=Release \
    -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
    -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
    -DEXECUTORCH_BUILD_EXTENSION_TENSOR=ON \
    -DEXECUTORCH_BUILD_QNN=ON \
    -DQNN_SDK_ROOT=${QNN_SDK_ROOT} \
    -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON \
    -DEXECUTORCH_BUILD_KERNELS_OPTIMIZED=ON \
    -DEXECUTORCH_BUILD_KERNELS_CUSTOM=ON \
    -Bcmake-out .

and I can overcome this by hardcode https://github.com/pytorch/executorch/blob/main/backends/qualcomm/runtime/backends/CMakeLists.txt#L48 to be aarch64

2. then the command
   cmake --build cmake-out -j16 --target install --config Release
   is giving me
   `[ 1%] Building CXX object third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/src/gflags.cc.o
   [ 1%] Building CXX object third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/src/gflags_reporting.cc.o
   [ 1%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_binary.cpp.o
   [ 1%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_parser.cpp.o
   [ 2%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_text.cpp.o
   [ 2%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_csharp.cpp.o
   [ 2%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_kotlin.cpp.o
   [ 2%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/reflection.cpp.o
   [ 2%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/util.cpp.o
   [ 3%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_cpp.cpp.o
   [ 3%] Building CXX object third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/src/gflags_completions.cc.o
   [ 3%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_dart.cpp.o
   [ 5%] Built target pthreadpool
   [ 7%] Built target cpuinfo
   [ 9%] Built target cpuinfo_internals
   [ 10%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_kotlin_kmp.cpp.o
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_parser.cpp:17:10: fatal error: 'algorithm' file not found
   17 | #include
   | ^~~~~~~~~~~
   /Users/tianhaogu/Documents/executorch/third-party/gflags/src/gflags_reporting.cc:51:10: fatal error: 'cstdio' file not found
   51 | #include
   | ^~~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_binary.cpp:19:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_binary.h:20:10: fatal error: 'memory' file not found
   20 | #include
   | ^~~~~~~~
   [ 11%] Building CXX object kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/single.cpp.o
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_csharp.cpp:19:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_csharp.h:20:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/code_generator.h:20:10: fatal error: 'string' file not found
   20 | #include
   | ^~~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/gflags/src/gflags.cc:91:
   /Users/tianhaogu/Documents/executorch/cmake-out/third-party/gflags/include/gflags/gflags.h:81:10: fatal error: 'string' file not found
   81 | #include
   | ^~~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_kotlin.cpp:19:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_kotlin.h:20:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/code_generator.h:20:10: fatal error: 'string' file not found
   20 | #include
   | ^~~~~~~~
   [ 11%] Building CXX object kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/double.cpp.o
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/util.cpp:20:10: fatal error: 'cstring' file not found
   20 | #inclIn file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/reflection.cpp:17ude :

   | In file included from ^~~~~~~~~/Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/reflection.h
   :25:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/reflection_generated.h:7:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/flatbuffers.h:20:10: fatal error: 'algorithm' file not found
   20 | #include
   | ^~~~~~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_cpp.cpp:19:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_cpp.h:20:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/code_generator.h:20:10: fatal error: 'string' file not found
   20 | #include
   | ^~~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_text.cpp:18:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_text.h:20:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/code_generator.h:20:10: fatal error: 'string' file not found
   20 | #include
   | ^~~~~~~~
   [ 11%] Building CXX object third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_go.cpp.o
   /Users/tianhaogu/Documents/executorch/third-party/gflags/src/gflags_completions.cc:49:10: fatal error: 'cstdio' file not found
   49 | #include
   | ^~~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_dart.cpp:18:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_dart.h:20:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/code_generator.h:20:10: fatal error: 'string' file not found
   20 | #include
   | ^~~~~~~~
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_kotlin_kmp.cpp:19:10: fatal error: 'functional' file not found
   19 | #include
   | ^~~~~~~~~~~~
   In file included from In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/double.cpp/Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/single.cpp::1615:
   :
   In file included from In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/level1_impl.h/Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/level1_impl.h::10:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/common.h:21:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/Core:19:
   /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/src/Core/util/Macros.h:10714:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/common.h:21:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/Core:19:
   /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/src/Core/util/Macros.h:714:10: fatal error: 'cmath' file not found
   : 714 | #in10c:l udefatal error: <c'cmath' file not foundmath>

   | ^~~~~~~
   714 | #include
   | ^~~~~~~
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_go.cpp:19:
   In file included from /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/src/idl_gen_go.h:20:
   /Users/tianhaogu/Documents/executorch/third-party/flatbuffers/include/flatbuffers/code_generator.h:20:10: fatal error: 'string' file not found
   20 | #include
   | ^~~~~~~~
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/util.cpp.o] Error 1
   make[2]: *** Waiting for unfinished jobs....
   11 error error generated.
   generated.
   make[2]: *** [third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/src/gflags_completions.cc.o] Error 1
   make[2]: *** Waiting for unfinished jobs....
   1 error generated.
   make[2]: *** [third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/src/gflags_reporting.cc.o] Error 1
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/reflection.cpp.o] Error 1
   make[2]: *** [third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/src/gflags.cc.o] Error 1
   make[1]: *** [third-party/gflags/CMakeFiles/gflags_nothreads_static.dir/all] Error 2
   make[1]: *** Waiting for unfinished jobs....
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_binary.cpp.o] Error 1
   1 error generated.
   1 error generated.
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_csharp.cpp.o] Error 1
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_text.cpp.o] Error 1
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_cpp.cpp.o] Error 1
   [ 11%] Building CXX object kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/complex_single.cpp.o
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_dart.cpp.o] Error 1
   1 error generated.
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_parser.cpp.o] Error 1
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_kotlin.cpp.o] Error 1
   [ 11%] Building CXX object kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/complex_double.cpp.o
   1 error generated.
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_kotlin_kmp.cpp.o] Error 1
   1 error generated.
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/complex_single.cpp:16:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/level1_impl.h:10:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/common.h:21:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/Core:19:
   /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/src/Core/util/Macros.h:714:10: fatal error: 'cmath' file not found
   714 | #include
   | ^~~~~~~
   make[2]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/src/idl_gen_go.cpp.o] Error 1
   make[1]: *** [third-party/flatbuffers/CMakeFiles/flatc.dir/all] Error 2
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/complex_double.cpp:16:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/level1_impl.h:10:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/common.h:21:
   In file included from /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/Core:19:
   /Users/tianhaogu/Documents/executorch/kernels/optimized/third-party/eigen/blas/../Eigen/src/Core/util/Macros.h:714:10: fatal error: 'cmath' file not found
   714 | #include
   | ^~~~~~~
   1 error generated.
   1 error generated.
   make[2]: *** [kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/double.cpp.o] Error 1
   make[2]: *** Waiting for unfinished jobs....
   make[2]: *** [kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/single.cpp.o] Error 1
   1 error generated.
   1 error generated.
   make[2]: *** [kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/complex_double.cpp.o] Error 1
   make[2]: *** [kernels/optimized/CMakeFiles/eigen_blas.dir/third-party/eigen/blas/complex_single.cpp.o] Error 1
   make[1]: *** [kernels/optimized/CMakeFiles/eigen_blas.dir/all] Error 2
   make: *** [all] Error 2
   `

I had similar symptom with #5570 which i had issue with when running ./install_executorch.sh but I've already set the xcode to be correct path in my environment.

Versions

Collecting environment information...
PyTorch version: 2.6.0.dev20250104
Is debug build: False
CUDA used to build PyTorch: None
ROCM used to build PyTorch: N/A

OS: macOS 15.3 (arm64)
GCC version: Could not collect
Clang version: 16.0.0 (clang-1600.0.26.6)
CMake version: version 3.31.4
Libc version: N/A

Python version: 3.10.0 (default, Mar 3 2022, 03:54:28) [Clang 12.0.0 ] (64-bit runtime)
Python platform: macOS-15.3-arm64-arm-64bit
Is CUDA available: False
CUDA runtime version: No CUDA
CUDA_MODULE_LOADING set to: N/A
GPU models and configuration: No CUDA
Nvidia driver version: No CUDA
cuDNN version: No CUDA
HIP runtime version: N/A
MIOpen runtime version: N/A
Is XNNPACK available: True

CPU:
Apple M1 Pro

Versions of relevant libraries:
[pip3] executorch==0.6.0a0+733973
[pip3] numpy==2.2.2
[pip3] torch==2.6.0.dev20250104
[pip3] torchao==0.8.0+git11333ba2
[pip3] torchaudio==2.6.0.dev20250104
[pip3] torchsr==1.0.4
[pip3] torchvision==0.22.0.dev20250104
[conda] executorch 0.6.0a0+733973 pypi_0 pypi
[conda] numpy 2.2.2 pypi_0 pypi
[conda] torch 2.6.0.dev20250104 pypi_0 pypi
[conda] torchao 0.8.0+git11333ba2 pypi_0 pypi
[conda] torchaudio 2.6.0.dev20250104 pypi_0 pypi
[conda] torchsr 1.0.4 pypi_0 pypi
[conda] torchvision 0.22.0.dev20250104 pypi_0 pypi

cc @cccclai

[cccclai]

QNN only supports linux and windows, and we only verify the QNN backend build on linux at the moment and looking into windows build. However, the error message seems like a mismatch flatbuffers issue. Were you able to run ./install_executorch.sh?