Stop packaging the unused Apple LiteRT companion libraries from v0.19

README.md

@@ -326,7 +326,10 @@ v0.18 this includes the iOS `LiteRtMetalAccelerator` and
 `LiteRtTopKMetalSampler` modules; their framework-relative loader paths avoid
 flat dylibs that App Store bundles cannot ship. v0.19 `LiteRtLm` links its GPU
 accelerator and sampler, so neither is needed; releases after `v0.19.1-2` ship
-no Metal module.
+no Metal module. Releases after `v0.19.1-3` also drop the macOS `libLiteRt` and
+`libLiteRtWebGpuAccelerator` dylibs, the iOS loose `libLiteRt` and the matching
+`LiteRt` and `LiteRtWebGpuAccelerator` XCFramework zips: v0.19 `LiteRtLm`
+embeds LiteRT and never opens them.
 
 The macOS packager embeds the primary framework's private dylib dependencies
 inside `LiteRtLm.framework/Versions/A/Dependencies` and rewrites their loader

docs/platform_strategy.md

@@ -209,8 +209,11 @@ sections, such as EmbeddingGemma-2. The build fails if a v0.19+ host on any
 platform still imports `libLiteRt`, and those hosts report
 `litert_lm_native_in_process_litert_abi_version()` 1, so consumers can refuse
 external-weight bundles on older desktop runtimes. Bundles keep shipping the
-upstream `libLiteRt` and `libLiteRtWebGpuAccelerator` files so the consumer
-layout is unchanged, but the host loads neither.
+upstream `libLiteRt` and `libLiteRtWebGpuAccelerator` files on Linux, Windows
+and Android, but the host loads neither. Apple bundles after `v0.19.1-3` omit
+the macOS `libLiteRt` and `libLiteRtWebGpuAccelerator` and the iOS loose
+`libLiteRt` (`has_prebuilt_apple_litert_companions`), and so publish no
+`LiteRt` or `LiteRtWebGpuAccelerator` XCFramework.
 
 The rest of this section covers v0.16 to v0.18.
 

docs/v019_qualification.md

@@ -34,6 +34,7 @@ The exact-tag verification gate remains enabled.
 | Protos | `Asr*` became `Speech2Text*` | Internal to the adapter. |
 | Packaging | No `LiteRtTopK*Sampler` library; `libLiteRtLm` links Dawn | Validators and manifests key this on `has_prebuilt_topk_samplers`. |
 | Apple GPU | `LiteRtLm` links its GPU accelerator: ml_drift Metal on iOS, WebGPU on macOS | LiteRT registers it before searching for a shared one, so the prebuilt Metal accelerator is never opened ([llamadart#1798](https://github.com/leehack/llamadart/issues/1798)). Packaging after `v0.19.1-2` skips it on iOS and macOS, requires the static accelerator symbol in `LiteRtLm`, and rejects a candidate that still ships it (`has_prebuilt_apple_metal_accelerator`). |
+| Apple LiteRT companions | `LiteRtLm` embeds LiteRT and its GPU accelerator | dyld traces on macOS (CPU, GPU, vision, audio, MTP, embeddings, ASR) and an iOS simulator probe load neither `libLiteRt` nor `libLiteRtWebGpuAccelerator` ([llamadart#1911](https://github.com/leehack/llamadart/issues/1911)). Packaging after `v0.19.1-3` skips the macOS `libLiteRt` and `libLiteRtWebGpuAccelerator` and the iOS loose `libLiteRt`, and rejects a candidate that still ships them (`has_prebuilt_apple_litert_companions`). |
 
 `ubuntu-latest` moved to 26.04, so a Linux x64 build there needs glibc 2.43 and
 fails to load on Ubuntu 24.04. Linux x64 now builds on `ubuntu-24.04` and

tools/litert_lm_symbols.py

@@ -96,6 +96,8 @@
 ]
 
 APPLE_METAL_ACCELERATOR_LIBRARY = "libLiteRtMetalAccelerator.dylib"
+APPLE_LITERT_LIBRARY = "libLiteRt.dylib"
+APPLE_WEBGPU_ACCELERATOR_LIBRARY = "libLiteRtWebGpuAccelerator.dylib"
 
 # LiteRT registers a statically linked GPU accelerator before it searches for a
 # shared one (gpu_registry.cc), so these classes make the prebuilt Metal
@@ -161,6 +163,11 @@ def has_prebuilt_apple_metal_accelerator(upstream_tag: str) -> bool:
     return not is_at_least(upstream_tag, (0, 19, 0))
 
 
+def has_prebuilt_apple_litert_companions(upstream_tag: str) -> bool:
+    """v0.19 LiteRtLm embeds LiteRT, so Apple never opens libLiteRt or the WebGPU accelerator."""
+    return not is_at_least(upstream_tag, (0, 19, 0))
+
+
 def required_bridge_symbols(upstream_tag: str) -> list[bytes]:
     symbols = list(BRIDGE_SYMBOLS)
     if has_asr_bridge(upstream_tag):

tools/package_upstream_prebuilts.py

@@ -12,6 +12,9 @@
 from git_lfs_utils import materialize_git_lfs_libraries
 from litert_lm_symbols import (
     APPLE_METAL_ACCELERATOR_LIBRARY,
+    APPLE_LITERT_LIBRARY,
+    APPLE_WEBGPU_ACCELERATOR_LIBRARY,
+    has_prebuilt_apple_litert_companions,
     has_prebuilt_apple_metal_accelerator,
 )
 from prebuilt_overrides import (
@@ -66,11 +69,15 @@ def extract_source(archive: Path, output_dir: Path) -> Path:
 
 
 def unused_prebuilts(upstream_tag: str, platform: str) -> frozenset[str]:
-    if platform in {"ios", "macos"} and not has_prebuilt_apple_metal_accelerator(
-        upstream_tag
-    ):
-        return frozenset({APPLE_METAL_ACCELERATOR_LIBRARY})
-    return frozenset()
+    unused: set[str] = set()
+    if platform in {"ios", "macos"}:
+        if not has_prebuilt_apple_metal_accelerator(upstream_tag):
+            unused.add(APPLE_METAL_ACCELERATOR_LIBRARY)
+        if not has_prebuilt_apple_litert_companions(upstream_tag):
+            unused.add(APPLE_LITERT_LIBRARY)
+            if platform == "macos":
+                unused.add(APPLE_WEBGPU_ACCELERATOR_LIBRARY)
+    return frozenset(unused)
 
 
 def copy_prebuilts(

tools/test_package_upstream_prebuilts.py

@@ -67,19 +67,40 @@ def materialize(
                 b"\x7fELF materialized",
             )
 
-    def test_skips_apple_metal_accelerator_from_v019(self) -> None:
+    def test_skips_unused_apple_libraries_from_v019(self) -> None:
         targets = {
             "macos_arm64": ("macos", "arm64"),
             "ios_arm64": ("ios", "arm64"),
+            "ios_arm64_sim": ("ios", "arm64-sim"),
             "android_arm64": ("android", "arm64"),
+            "linux_x86_64": ("linux", "x64"),
+            "windows_x86_64": ("windows", "x64"),
         }
-        for tag, metal_copied in (("v0.18.1", True), ("v0.19.1", False)):
+        names = (
+            "libLiteRt.dylib",
+            "libLiteRtMetalAccelerator.dylib",
+            "libLiteRtWebGpuAccelerator.dylib",
+            "libLiteRtLm.dylib",
+        )
+        removed_v019 = {
+            ("macos", "arm64"): {
+                "libLiteRt.dylib",
+                "libLiteRtMetalAccelerator.dylib",
+                "libLiteRtWebGpuAccelerator.dylib",
+            },
+            ("ios", "arm64"): {"libLiteRt.dylib", "libLiteRtMetalAccelerator.dylib"},
+            ("ios", "arm64-sim"): {
+                "libLiteRt.dylib",
+                "libLiteRtMetalAccelerator.dylib",
+            },
+        }
+        for tag in ("v0.18.1", "v0.19.1"):
             with self.subTest(tag=tag), tempfile.TemporaryDirectory() as temp:
                 root = Path(temp)
                 for upstream_name in targets:
                     source_dir = root / "source" / "prebuilt" / upstream_name
                     source_dir.mkdir(parents=True)
-                    for name in ("libLiteRt.dylib", "libLiteRtMetalAccelerator.dylib"):
+                    for name in names:
                         (source_dir / name).write_bytes(b"binary")
                 output = root / "bin"
                 with patch.object(package_upstream_prebuilts, "BIN_DIR", output), \
@@ -89,13 +110,12 @@ def test_skips_apple_metal_accelerator_from_v019(self) -> None:
                     package_upstream_prebuilts.copy_prebuilts(
                         root / "source", upstream_tag=tag, clean=True)
 
-                for platform in ("macos", "ios", "android"):
-                    staged = output / platform / "arm64"
-                    self.assertTrue((staged / "libLiteRt.dylib").is_file())
-                    self.assertEqual(
-                        (staged / "libLiteRtMetalAccelerator.dylib").is_file(),
-                        metal_copied or platform == "android",
-                    )
+                for platform, arch in targets.values():
+                    staged = {p.name for p in (output / platform / arch).iterdir()}
+                    expected = set(names)
+                    if tag == "v0.19.1":
+                        expected -= removed_v019.get((platform, arch), set())
+                    self.assertEqual(staged, expected, (platform, arch))
 
     def test_overrides_only_does_not_download_or_copy_upstream_source(self) -> None:
         with patch(

tools/test_v019_decisions.py

@@ -11,6 +11,7 @@
 from ios_runtime_policy import verify_upstream_fst_gate
 from litert_lm_symbols import (
     APPLE_STATIC_GPU_ACCELERATOR_SYMBOLS,
+    has_prebuilt_apple_litert_companions,
     has_prebuilt_apple_metal_accelerator,
     has_prebuilt_topk_samplers,
     required_bridge_symbols,
@@ -71,7 +72,7 @@ def test_apple_metal_accelerator_packaging_stops_at_v019(self) -> None:
         self.assertFalse([p for p in required_runtime_artifacts("v0.19.1") if "Metal" in str(p)])
         self.assertEqual(forbidden_runtime_artifacts("v0.18.1"), [])
         self.assertEqual(
-            {p.as_posix() for p in forbidden_runtime_artifacts("v0.19.1")},
+            {p.as_posix() for p in forbidden_runtime_artifacts("v0.19.1") if "Metal" in p.name},
             {
                 "bin/ios/arm64/LiteRtMetalAccelerator.framework/LiteRtMetalAccelerator",
                 "bin/ios/arm64-sim/LiteRtMetalAccelerator.framework/LiteRtMetalAccelerator",
@@ -81,6 +82,27 @@ def test_apple_metal_accelerator_packaging_stops_at_v019(self) -> None:
             },
         )
 
+    def test_apple_litert_companion_packaging_stops_at_v019(self) -> None:
+        litert_zips = {
+            "litert-lm-native-apple-LiteRt-xcframework-{tag}.zip",
+            "litert-lm-native-apple-LiteRtWebGpuAccelerator-xcframework-{tag}.zip",
+        }
+        self.assertTrue(has_prebuilt_apple_litert_companions("v0.18.1"))
+        self.assertFalse(has_prebuilt_apple_litert_companions("v0.19.1"))
+        self.assertTrue(litert_zips <= set(allowed_spm_assets("v0.18.1")))
+        self.assertFalse(litert_zips & set(allowed_spm_assets("v0.19.1")))
+        self.assertFalse(litert_zips & set(required_spm_assets("v0.19.1")))
+        self.assertEqual(forbidden_runtime_artifacts("v0.18.1"), [])
+        self.assertLessEqual(
+            {
+                "bin/ios/arm64/libLiteRt.dylib",
+                "bin/ios/arm64-sim/libLiteRt.dylib",
+                "bin/macos/arm64/libLiteRt.dylib",
+                "bin/macos/arm64/libLiteRtWebGpuAccelerator.dylib",
+            },
+            {p.as_posix() for p in forbidden_runtime_artifacts("v0.19.1")},
+        )
+
     def test_v019_apple_runtimes_require_a_static_gpu_accelerator(self) -> None:
         required = (required_c_api_symbols("v0.19.1")
                     + required_bridge_symbols("v0.19.1"))

tools/validate_release_manifest.py

@@ -11,6 +11,7 @@
 from fetch_litert_lm_asr_smoke_assets import ASSETS
 from litert_lm_symbols import (
     has_asr_bridge,
+    has_prebuilt_apple_litert_companions,
     has_prebuilt_apple_metal_accelerator,
     has_prebuilt_topk_samplers,
     is_at_least,
@@ -54,10 +55,13 @@
 
 # The Apple packager emits these when their pinned v0.16 runtime inputs exist.
 # Keep the optional inventory explicit so arbitrary manifest-added zips still fail.
-V0_16_ALLOWED_SPM_COMPANION_XCFRAMEWORKS = [
-    "litert-lm-native-apple-GemmaModelConstraintProvider-xcframework-{tag}.zip",
+APPLE_LITERT_COMPANION_SPM_XCFRAMEWORKS = [
     "litert-lm-native-apple-LiteRt-xcframework-{tag}.zip",
     "litert-lm-native-apple-LiteRtWebGpuAccelerator-xcframework-{tag}.zip",
+]
+
+V0_16_ALLOWED_SPM_COMPANION_XCFRAMEWORKS = [
+    "litert-lm-native-apple-GemmaModelConstraintProvider-xcframework-{tag}.zip",
     "litert-lm-native-apple-WebgpuDawn-xcframework-{tag}.zip",
 ]
 
@@ -634,6 +638,8 @@ def allowed_spm_assets(compatibility_tag: str) -> list[str]:
     assets = required_spm_assets(compatibility_tag)
     if is_at_least(compatibility_tag, (0, 16, 0)):
         assets.extend(V0_16_ALLOWED_SPM_COMPANION_XCFRAMEWORKS)
+        if has_prebuilt_apple_litert_companions(compatibility_tag):
+            assets.extend(APPLE_LITERT_COMPANION_SPM_XCFRAMEWORKS)
         if has_prebuilt_topk_samplers(compatibility_tag):
             assets.append(
                 "litert-lm-native-apple-LiteRtTopKWebGpuSampler-xcframework-{tag}.zip"

tools/validate_runtime_artifacts.py

@@ -5,6 +5,7 @@
 from pathlib import Path
 
 from litert_lm_symbols import (
+    has_prebuilt_apple_litert_companions,
     has_prebuilt_apple_metal_accelerator,
     has_prebuilt_topk_samplers,
     is_at_least,
@@ -38,6 +39,13 @@
     Path("bin/macos/arm64/libLiteRtMetalAccelerator.dylib"),
 ]
 
+APPLE_LITERT_COMPANION_ARTIFACTS = [
+    Path("bin/ios/arm64/libLiteRt.dylib"),
+    Path("bin/ios/arm64-sim/libLiteRt.dylib"),
+    Path("bin/macos/arm64/libLiteRt.dylib"),
+    Path("bin/macos/arm64/libLiteRtWebGpuAccelerator.dylib"),
+]
+
 PREBUILT_SAMPLER_IOS_ARTIFACTS = [
     Path("bin/ios/arm64/LiteRtTopKMetalSampler.framework/LiteRtTopKMetalSampler"),
     Path("bin/ios/arm64-sim/LiteRtTopKMetalSampler.framework/LiteRtTopKMetalSampler"),
@@ -69,9 +77,12 @@ def required_runtime_artifacts(
 
 
 def forbidden_runtime_artifacts(upstream_tag: str) -> list[Path]:
-    if has_prebuilt_apple_metal_accelerator(upstream_tag):
-        return []
-    return list(APPLE_METAL_ACCELERATOR_ARTIFACTS)
+    forbidden: list[Path] = []
+    if not has_prebuilt_apple_metal_accelerator(upstream_tag):
+        forbidden.extend(APPLE_METAL_ACCELERATOR_ARTIFACTS)
+    if not has_prebuilt_apple_litert_companions(upstream_tag):
+        forbidden.extend(APPLE_LITERT_COMPANION_ARTIFACTS)
+    return forbidden
 
 
 def main() -> int: