[WIP] [Not Ready for Review] executorch load

MODULE.bazel

@@ -26,6 +26,13 @@ new_local_repository = use_repo_rule("@bazel_tools//tools/build_defs/repo:local.
 
 local_torch = use_repo_rule("//toolchains:local_torch.bzl", "local_torch")
 
+local_executorch = use_repo_rule("//toolchains:local_executorch.bzl", "local_executorch")
+
+# Detect the locally installed ExecuTorch source tree at build time.
+# Set EXECUTORCH_PATH to the directory containing runtime/, extension/, cmake-out/.
+# Requires cmake-out/libexecutorch_core.a to be built first.
+local_executorch(name = "executorch")
+
 # External dependency for torch_tensorrt if you already have precompiled binaries.
 new_local_repository(
     name = "torch_tensorrt",
@@ -77,6 +84,15 @@ local_torch(name = "libtorch")
 #    build_file = "third_party/libtorch/BUILD"
 #)
 
+# ExecuTorch source tree.  The repository root is the *parent* of the
+# executorch/ directory so that headers resolve as <executorch/runtime/...>.
+# Requires a cmake-out/ build inside the executorch source tree.
+#new_local_repository(
+#    name = "executorch",
+#    build_file = "@//third_party/executorch:BUILD",
+#    path = "/home/lanl/git/executorch",
+#)
+
 #new_local_repository(
 #   name = "tensorrt",
 #   path = "/usr/",

core/runtime/BUILD

@@ -1,6 +1,7 @@
 load("@rules_cc//cc:defs.bzl", "cc_library")
 load("@rules_pkg//:pkg.bzl", "pkg_tar")
 load("@rules_pkg//pkg:mappings.bzl", "pkg_files")
+
 package(default_visibility = ["//visibility:public"])
 
 config_setting(
@@ -58,17 +59,22 @@ config_setting(
     ],
 )
 
+# runtime_base: TRTEngine + device management + serialization utilities.
+# Does NOT include register_jit_hooks.cpp (TorchScript torch::class_ /
+# TORCH_LIBRARY registrations), so it can be linked into
+# libtrt_executorch_backend.so without causing a duplicate-registration
+# crash when libtorchtrt.so is also loaded in the same process.
 cc_library(
-    name = "runtime",
+    name = "runtime_base",
     srcs = [
         "DeviceList.cpp",
         "Platform.cpp",
         "RTDevice.cpp",
         "TRTEngine.cpp",
         "TRTEngineProfiler.cpp",
         "execute_engine.cpp",
-        "register_jit_hooks.cpp",
         "runtime.cpp",
+        "runtime_utils.cpp",
     ],
     hdrs = [
         "Platform.h",
@@ -100,6 +106,26 @@ cc_library(
     alwayslink = True,
 )
 
+# runtime: full runtime including TorchScript torch::class_ / TORCH_LIBRARY
+# registrations. Used by the main libtorchtrt.so.
+cc_library(
+    name = "runtime",
+    srcs = [
+        "register_jit_hooks.cpp",
+    ],
+    hdrs = [
+        "Platform.h",
+        "RTDevice.h",
+        "TRTEngine.h",
+        "TRTEngineProfiler.h",
+        "runtime.h",
+    ],
+    deps = [
+        ":runtime_base",
+    ],
+    alwayslink = True,
+)
+
 filegroup(
     name = "include_files",
     srcs = [
@@ -121,6 +147,6 @@ pkg_tar(
 pkg_files(
     name = "include_pkg_files",
     srcs = [":include_files"],
-    visibility = ["//visibility:public"],
     prefix = "include/torch_tensorrt/core/runtime/",
+    visibility = ["//visibility:public"],
 )

core/runtime/TRTEngine.cpp

@@ -447,6 +447,29 @@ TRTEngine& TRTEngine::operator=(const TRTEngine& other) {
 }
 
 void TRTEngine::verify_serialization_fmt(const std::vector<std::string>& serialized_info) {
+  static const char* kIndexNames[] = {
+      "ABI_TARGET_IDX",
+      "NAME_IDX",
+      "DEVICE_IDX",
+      "ENGINE_IDX",
+      "INPUT_BINDING_NAMES_IDX",
+      "OUTPUT_BINDING_NAMES_IDX",
+      "HW_COMPATIBLE_IDX",
+      "SERIALIZED_METADATA_IDX",
+      "TARGET_PLATFORM_IDX",
+      "REQUIRES_OUTPUT_ALLOCATOR_IDX",
+      "RESOURCE_ALLOCATION_STRATEGY_IDX",
+  };
+  fprintf(stderr, "[verify_serialization_fmt] %zu entries (expected %d):\n", serialized_info.size(), SERIALIZATION_LEN);
+  for (size_t i = 0; i < serialized_info.size(); ++i) {
+    const char* name = (i < sizeof(kIndexNames) / sizeof(kIndexNames[0])) ? kIndexNames[i] : "?";
+    if (i == ENGINE_IDX) {
+      fprintf(stderr, "  [%zu] %-35s = <binary, %zu bytes>\n", i, name, serialized_info[i].size());
+    } else {
+      fprintf(stderr, "  [%zu] %-35s = \"%s\"\n", i, name, serialized_info[i].c_str());
+    }
+  }
+
   TORCHTRT_CHECK(
       serialized_info.size() == SERIALIZATION_LEN,
       "Program to be deserialized targets an incompatible Torch-TensorRT ABI");

core/runtime/executorch/BUILD

@@ -0,0 +1,82 @@
+load("@rules_cc//cc:defs.bzl", "cc_library")
+
+package(default_visibility = ["//visibility:public"])
+
+config_setting(
+    name = "use_torch_whl",
+    flag_values = {
+        "//toolchains/dep_src:torch": "whl",
+    },
+)
+
+config_setting(
+    name = "rtx_x86_64",
+    constraint_values = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+    flag_values = {
+        "//toolchains/dep_collection:compute_libs": "rtx",
+    },
+)
+
+config_setting(
+    name = "rtx_win",
+    constraint_values = [
+        "@platforms//os:windows",
+    ],
+    flag_values = {
+        "//toolchains/dep_collection:compute_libs": "rtx",
+    },
+)
+
+config_setting(
+    name = "sbsa",
+    constraint_values = [
+        "@platforms//cpu:aarch64",
+    ],
+    flag_values = {
+        "//toolchains/dep_collection:compute_libs": "default",
+    },
+)
+
+config_setting(
+    name = "jetpack",
+    constraint_values = [
+        "@platforms//cpu:aarch64",
+    ],
+    flag_values = {
+        "//toolchains/dep_collection:compute_libs": "jetpack",
+    },
+)
+
+config_setting(
+    name = "windows",
+    constraint_values = [
+        "@platforms//os:windows",
+    ],
+)
+
+cc_library(
+    name = "tensorrt_executorch_backend",
+    srcs = ["TensorRTBackend.cpp"],
+    hdrs = ["TensorRTBackend.h"],
+    # Use executorch_headers (no static link) so that register_backend /
+    # find_backend / FreeableBuffer etc. remain undefined symbols in the
+    # final libtrt_executorch_backend.so.  At runtime they are resolved from
+    # libqnn_executorch_backend.so, which _portable_lib.so loads with
+    # RTLD_GLOBAL, ensuring both share the same registry instance.
+    deps = [
+        "//core/runtime:runtime_base",
+        "//core/util:prelude",
+        "@executorch//:executorch_headers",
+    ] + select({
+        ":jetpack": ["@tensorrt_l4t//:nvinfer"],
+        ":rtx_win": ["@tensorrt_rtx_win//:nvinfer"],
+        ":rtx_x86_64": ["@tensorrt_rtx//:nvinfer"],
+        ":sbsa": ["@tensorrt_sbsa//:nvinfer"],
+        ":windows": ["@tensorrt_win//:nvinfer"],
+        "//conditions:default": ["@tensorrt//:nvinfer"],
+    }),
+    alwayslink = True,
+)