Propagate hotness counter for backup method to target to avoid crash

Fix #99

See https://5ec1cff.github.io/my-blog/2024/06/27/lsp-crash-analysis/

lsplant/src/main/jni/CMakeLists.txt

@@ -16,8 +16,8 @@ if (LSPLANT_STANDALONE)
 endif()
 
 set(SOURCES lsplant.cc)
-file(GLOB_RECURSE MODULE_SOURCES "*.cxx")
-file(GLOB_RECURSE MODULE_INTERFACES "*.ixx")
+file(GLOB_RECURSE MODULE_SOURCES CONFIGURE_DEPENDS "*.cxx")
+file(GLOB_RECURSE MODULE_INTERFACES CONFIGURE_DEPENDS "*.ixx")
 
 set(DEX_BUILDER_BUILD_SHARED OFF CACHE INTERNAL "" FORCE)
 add_subdirectory(external/dex_builder)

lsplant/src/main/jni/art/runtime/jit/jit.cxx

@@ -0,0 +1,56 @@
+module;
+
+#include "logging.hpp"
+#include "utils/hook_helper.hpp"
+
+export module jit;
+
+import art_method;
+import common;
+import thread;
+
+namespace lsplant::art::jit {
+enum class CompilationKind {
+    kOsr [[maybe_unused]],
+    kBaseline [[maybe_unused]],
+    kOptimized,
+};
+
+export class Jit {
+    CREATE_MEM_HOOK_STUB_ENTRY(
+        "_ZN3art3jit3Jit27EnqueueOptimizedCompilationEPNS_9ArtMethodEPNS_6ThreadE", void,
+        EnqueueOptimizedCompilation, (Jit * thiz, ArtMethod *method, Thread *self), {
+            if (auto target = IsBackup(method); target) [[unlikely]] {
+                LOGD("Propagate enqueue compilation: %p -> %p", method, target);
+                method = target;
+            }
+            return backup(thiz, method, self);
+        });
+
+    CREATE_MEM_HOOK_STUB_ENTRY(
+        "_ZN3art3jit3Jit14AddCompileTaskEPNS_6ThreadEPNS_9ArtMethodENS_15CompilationKindEb", void,
+        AddCompileTask,
+        (Jit * thiz, Thread *self, ArtMethod *method, CompilationKind compilation_kind,
+         bool precompile),
+        {
+            if (compilation_kind == CompilationKind::kOptimized && !precompile/* && in_enqueue*/) {
+                if (auto backup = IsHooked(method); backup) [[unlikely]] {
+                    LOGD("Propagate compile task: %p -> %p", method, backup);
+                    method = backup;
+                }
+            }
+            return backup(thiz, self, method, compilation_kind, precompile);
+        });
+
+public:
+    static bool Init(const HookHandler &handler) {
+        auto sdk_int = GetAndroidApiLevel();
+
+        if (sdk_int <= __ANDROID_API_U__) [[likely]] {
+            HookSyms(handler, EnqueueOptimizedCompilation);
+            HookSyms(handler, AddCompileTask);
+        }
+        return true;
+    }
+};
+}  // namespace lsplant::art::jit

lsplant/src/main/jni/common.cxx

@@ -69,7 +69,7 @@ export {
         return v + size - 1 - ((v + size - 1) & (size - 1));
     }
 
-    inline auto GetAndroidApiLevel() {
+    [[gnu::const]] inline auto GetAndroidApiLevel() {
         static auto kApiLevel = []() {
             std::array<char, PROP_VALUE_MAX> prop_value;
             __system_property_get("ro.build.version.sdk", prop_value.data());

lsplant/src/main/jni/lsplant.cc

@@ -25,6 +25,7 @@ import scope_gc_critical_section;
 import jit_code_cache;
 import jni_id_manager;
 import dex_file;
+import jit;
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunknown-pragmas"
@@ -42,6 +43,7 @@ using art::Runtime;
 using art::Thread;
 using art::gc::ScopedGCCriticalSection;
 using art::jit::JitCodeCache;
+using art::jit::Jit;
 using art::jni::JniIdManager;
 using art::mirror::Class;
 using art::thread_list::ScopedSuspendAll;
@@ -286,6 +288,10 @@ bool InitNative(JNIEnv *env, const HookHandler &handler) {
         LOGE("Failed to init jit code cache");
         return false;
     }
+    if (!Jit::Init(handler)) {
+        LOGE("Failed to init jit");
+        return false;
+    }
     if (!DexFile::Init(env, handler)) {
         LOGE("Failed to init dex file");
         return false;