Allow building repository as CMake subdirectory (#2059)

* Use PROJECT_SOURCE_DIR rather than CMAKE_SOURCE_DIR to allow building as subdirectory

* Also use PROJECT_SOURCE_DIR instead of CMAKE_SOURCE_DIR in c/cxx api examples

* Only build examples by default when not building as subdirectory

* Do not suggest building binaries either

---------

Co-authored-by: user <user@mail.tld>

@@ -20,6 +20,13 @@ if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.24.0")
   cmake_policy(SET CMP0135 NEW)
 endif()
 
+
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  set(SUGGEST_BUILD_BINARIES ON)
+else()
+  set(SUGGEST_BUILD_BINARIES OFF)
+endif()
+
 option(SHERPA_ONNX_ENABLE_PYTHON "Whether to build Python" OFF)
 option(SHERPA_ONNX_ENABLE_TESTS "Whether to build tests" OFF)
 option(SHERPA_ONNX_ENABLE_CHECK "Whether to build with assert" OFF)
@@ -39,13 +46,13 @@ option(SHERPA_ONNX_ENABLE_WASM_VAD "Whether to enable WASM for VAD" OFF)
 option(SHERPA_ONNX_ENABLE_WASM_VAD_ASR "Whether to enable WASM for VAD+ASR" OFF)
 option(SHERPA_ONNX_ENABLE_WASM_NODEJS "Whether to enable WASM for NodeJS" OFF)
 option(SHERPA_ONNX_ENABLE_WASM_SPEECH_ENHANCEMENT "Whether to enable WASM for speech enhancement" OFF)
-option(SHERPA_ONNX_ENABLE_BINARY "Whether to build binaries" ON)
+option(SHERPA_ONNX_ENABLE_BINARY "Whether to build binaries" ${SUGGEST_BUILD_BINARIES})
 option(SHERPA_ONNX_ENABLE_TTS "Whether to build TTS related code" ON)
 option(SHERPA_ONNX_ENABLE_SPEAKER_DIARIZATION "Whether to build speaker diarization related code" ON)
 option(SHERPA_ONNX_LINK_LIBSTDCPP_STATICALLY "True to link libstdc++ statically. Used only when BUILD_SHARED_LIBS is OFF on Linux" ON)
 option(SHERPA_ONNX_USE_PRE_INSTALLED_ONNXRUNTIME_IF_AVAILABLE "True to use pre-installed onnxruntime if available" ON)
 option(SHERPA_ONNX_ENABLE_SANITIZER "Whether to enable ubsan and asan" OFF)
-option(SHERPA_ONNX_BUILD_C_API_EXAMPLES "Whether to enable C API examples" ON)
+option(SHERPA_ONNX_BUILD_C_API_EXAMPLES "Whether to enable C API examples" ${SUGGEST_BUILD_BINARIES})
 option(SHERPA_ONNX_ENABLE_RKNN "Whether to build for RKNN NPU " OFF)
 
 set(SHERPA_ONNX_LINUX_ARM64_GPU_ONNXRUNTIME_VERSION "1.11.0" CACHE STRING "Used only for Linux ARM64 GPU. Set to 1.11.0 if you use CUDA 10.2 and cudnn8. Set it to 1.16.0 if you use CUDA 11.4 and cudnn8. Set it to 1.18.0 if you use CUDA 12.2 and cudnn8. Set it to 1.18.1 if you use CUDA 12.6 and cudnn9")

 include(cargs)
 
-include_directories(${CMAKE_SOURCE_DIR})
+include_directories(${PROJECT_SOURCE_DIR})
 add_executable(decode-file-c-api decode-file-c-api.c)
 target_link_libraries(decode-file-c-api sherpa-onnx-c-api cargs)
 

-include_directories(${CMAKE_SOURCE_DIR})
+include_directories(${PROJECT_SOURCE_DIR})
 
 add_executable(streaming-zipformer-cxx-api ./streaming-zipformer-cxx-api.cc)
 target_link_libraries(streaming-zipformer-cxx-api sherpa-onnx-cxx-api)

-include_directories(${CMAKE_SOURCE_DIR})
+include_directories(${PROJECT_SOURCE_DIR})
 add_library(sherpa-onnx-c-api c-api.cc)
 target_link_libraries(sherpa-onnx-c-api sherpa-onnx-core)
+target_include_directories(sherpa-onnx-c-api PUBLIC ${PROJECT_SOURCE_DIR})
 
 if(BUILD_SHARED_LIBS)
   target_compile_definitions(sherpa-onnx-c-api PUBLIC SHERPA_ONNX_BUILD_SHARED_LIBS=1)
@@ -9,6 +10,7 @@ endif()
 
 add_library(sherpa-onnx-cxx-api cxx-api.cc)
 target_link_libraries(sherpa-onnx-cxx-api sherpa-onnx-c-api)
+target_include_directories(sherpa-onnx-cxx-api PUBLIC ${PROJECT_SOURCE_DIR})
 
 install(
   TARGETS

-include_directories(${CMAKE_SOURCE_DIR})
+include_directories(${PROJECT_SOURCE_DIR})
 
 if(SHERPA_ONNX_ENABLE_PYTHON)
   message(STATUS "PYTHON_EXECUTABLE: ${PYTHON_EXECUTABLE}")
@@ -648,7 +648,7 @@ endforeach()
 # For clang-tidy
 add_custom_target(
   clang-tidy-check
-  clang-tidy -p ${CMAKE_BINARY_DIR}/compile_commands.json --config-file ${CMAKE_SOURCE_DIR}/.clang-tidy ${srcs_to_check}
+  clang-tidy -p ${CMAKE_BINARY_DIR}/compile_commands.json --config-file ${PROJECT_SOURCE_DIR}/.clang-tidy ${srcs_to_check}
   DEPENDS ${sources})
 
 add_custom_target(check DEPENDS clang-tidy-check)

-include_directories(${CMAKE_SOURCE_DIR})
+include_directories(${PROJECT_SOURCE_DIR})
 
 if(NOT DEFINED ANDROID_ABI)
   if(NOT DEFINED ENV{JAVA_HOME})

-include_directories(${CMAKE_SOURCE_DIR})
+include_directories(${PROJECT_SOURCE_DIR})
 
 set(srcs
   audio-tagging.cc
@@ -51,7 +51,7 @@ set(srcs
   wave-writer.cc
 )
 if(SHERPA_ONNX_HAS_ALSA)
-  list(APPEND srcs ${CMAKE_SOURCE_DIR}/sherpa-onnx/csrc/alsa.cc alsa.cc)
+  list(APPEND srcs ${PROJECT_SOURCE_DIR}/sherpa-onnx/csrc/alsa.cc alsa.cc)
 else()
   list(APPEND srcs faked-alsa.cc)
 endif()