use flatc from conda instead of build from source (#429)

Summary: Pull Request resolved: #429

Differential Revision: D49487908

Author: cccclai

CMakeLists.txt

@@ -131,7 +131,7 @@ include(${EXECUTORCH_SRCS_FILE})
 
 if(NOT FLATC_EXECUTABLE)
   set(FLATC_EXECUTABLE flatc)
-  option(FLATBUFFERS_BUILD_FLATC "" ON)
+  option(FLATBUFFERS_BUILD_FLATC "" OFF)
   option(FLATBUFFERS_BUILD_FLATHASH "" OFF)
   option(FLATBUFFERS_BUILD_FLATLIB "" OFF)
   option(FLATBUFFERS_BUILD_TESTS "" OFF)

schema/CMakeLists.txt

@@ -41,7 +41,7 @@ add_custom_command(
     -o "${_program_schema__include_dir}/executorch/schema"
     ${_program_schema__srcs}
   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-  DEPENDS ${FLATC_EXECUTABLE} ${_program_schema__srcs}
+  DEPENDS ${_program_schema__srcs}
   COMMENT "Generating program_schema headers"
   VERBATIM)
 

third-party/TARGETS

@@ -169,35 +169,23 @@ runtime.cxx_binary(
         "flatbuffers/grpc/src/compiler/python_generator.cc",
         "flatbuffers/grpc/src/compiler/swift_generator.cc",
         "flatbuffers/grpc/src/compiler/ts_generator.cc",
-        "flatbuffers/src/annotated_binary_text_gen.cpp",
-        "flatbuffers/src/bfbs_gen_lua.cpp",
-        "flatbuffers/src/bfbs_gen_nim.cpp",
-        "flatbuffers/src/binary_annotator.cpp",
-        "flatbuffers/src/code_generators.cpp",
-        "flatbuffers/src/file_binary_writer.cpp",
-        "flatbuffers/src/file_name_saving_file_manager.cpp",
-        "flatbuffers/src/file_writer.cpp",
-        "flatbuffers/src/flatc.cpp",
         "flatbuffers/src/flatc_main.cpp",
-        "flatbuffers/src/idl_gen_binary.cpp",
         "flatbuffers/src/idl_gen_cpp.cpp",
         "flatbuffers/src/idl_gen_csharp.cpp",
         "flatbuffers/src/idl_gen_dart.cpp",
-        "flatbuffers/src/idl_gen_fbs.cpp",
         "flatbuffers/src/idl_gen_go.cpp",
         "flatbuffers/src/idl_gen_grpc.cpp",
         "flatbuffers/src/idl_gen_java.cpp",
+        "flatbuffers/src/idl_gen_js_ts.cpp",
         "flatbuffers/src/idl_gen_json_schema.cpp",
         "flatbuffers/src/idl_gen_kotlin.cpp",
         "flatbuffers/src/idl_gen_lobster.cpp",
+        "flatbuffers/src/idl_gen_lua.cpp",
         "flatbuffers/src/idl_gen_php.cpp",
         "flatbuffers/src/idl_gen_python.cpp",
         "flatbuffers/src/idl_gen_rust.cpp",
         "flatbuffers/src/idl_gen_swift.cpp",
         "flatbuffers/src/idl_gen_text.cpp",
-        "flatbuffers/src/idl_gen_ts.cpp",
-        "flatbuffers/src/idl_parser.cpp",
-        "flatbuffers/src/reflection.cpp",
         "flatbuffers/src/util.cpp",
     ],
     include_directories = [
@@ -209,6 +197,7 @@ runtime.cxx_binary(
         "flatbuffers/grpc/src/compiler/go_generator.h",
         "flatbuffers/grpc/src/compiler/java_generator.h",
         "flatbuffers/grpc/src/compiler/python_generator.h",
+        "flatbuffers/grpc/src/compiler/python_private_generator.h",
         "flatbuffers/grpc/src/compiler/schema_interface.h",
         "flatbuffers/grpc/src/compiler/swift_generator.h",
         "flatbuffers/grpc/src/compiler/ts_generator.h",
@@ -219,6 +208,7 @@ runtime.cxx_binary(
     _is_external_target = True,
 )
 
+
 runtime.genrule(
     name = "libtorch_gen",
     outs = select({