Don't preload jmethodIDs when cstack=vm with hotspot JVM

ddprof-lib/src/main/cpp/arguments.cpp

@@ -260,6 +260,11 @@ Error Arguments::parse(const char *args) {
         msg = "jstackdepth must be > 0";
       }
 
+      CASE("fjmethodid")
+      if (value != nullptr && strcmp(value, "false") == 0) {
+        _force_jmethodID = false;
+      }
+
       CASE("safemode")
       _safe_mode = value == NULL ? INT_MAX : (int)strtol(value, NULL, 0);
 

ddprof-lib/src/main/cpp/arguments.h

@@ -193,6 +193,7 @@ class Arguments {
   bool _enable_method_cleanup;
   bool _remote_symbolication;  // Enable remote symbolication for native frames
   bool _jvmtistacks;           // Delegate CPU/wall stack walks to HotSpot JFR RequestStackTrace extension
+  bool _force_jmethodID;       // Load all jmethodIDs, true by default
 
   Arguments(bool persistent = false)
       : _buf(NULL),
@@ -229,7 +230,8 @@ class Arguments {
         _lightweight(false),
         _enable_method_cleanup(true),
         _remote_symbolication(false),
-        _jvmtistacks(false) {}
+        _jvmtistacks(false),
+        _force_jmethodID(false) {}
 
   ~Arguments();
 

ddprof-lib/src/main/cpp/flightRecorder.cpp

@@ -13,10 +13,11 @@
 #include "context_api.h"
 #include "counters.h"
 #include "dictionary.h"
-#include "flightRecorder.h"
+#include "flightRecorder.inline.h"
 #include "incbin.h"
 #include "jfrMetadata.h"
 #include "jniHelper.h"
+#include "jvmSupport.inline.h"
 #include "os.h"
 #include "profiler.h"
 #include "signalSafety.h"
@@ -485,8 +486,12 @@ MethodInfo *Lookup::resolveMethod(ASGCT_CallFrame &frame) {
   static const char* UNKNOWN = "unknown";
   unsigned long key;
   jint bci = frame.bci;
+  jmethodID method_id = frame.method_id;
 
-  jmethodID method = frame.method_id;
+  // Resolve native method
+  if (FrameType::isRawPointer(bci)) {
+    method_id = JVMSupport::resolve(frame.method);
+  }
 
   // BCI_VTABLE_RECEIVER: method holds a VMSymbol* (see vmEntry.h). Resolve
   // to a class_id via the per-dump cache once, then key MethodMap by the
@@ -495,10 +500,10 @@ MethodInfo *Lookup::resolveMethod(ASGCT_CallFrame &frame) {
   // row.
   u32 vtable_class_id = 0;
   if (bci == BCI_VTABLE_RECEIVER) {
-    vtable_class_id = resolveVTableReceiverCached((void *)method);
+    vtable_class_id = resolveVTableReceiverCached((void *)method_id);
   }
 
-  if (method == nullptr) {
+  if (method_id == nullptr) {
     key = MethodMap::makeKey(UNKNOWN);
   } else if (bci == BCI_ERROR || bci == BCI_NATIVE_FRAME) {
     key = MethodMap::makeKey(frame.native_function_name);
@@ -511,7 +516,7 @@ MethodInfo *Lookup::resolveMethod(ASGCT_CallFrame &frame) {
     assert(frame_type == FRAME_INTERPRETED || frame_type == FRAME_JIT_COMPILED ||
            frame_type == FRAME_INLINED || frame_type == FRAME_C1_COMPILED ||
            VM::isOpenJ9()); // OpenJ9 may have bugs that produce invalid frame types
-    key = MethodMap::makeKey(method);
+    key = MethodMap::makeKey(method_id);
   }
 
   MethodInfo *mi = &(*_method_map)[key];
@@ -522,12 +527,12 @@ MethodInfo *Lookup::resolveMethod(ASGCT_CallFrame &frame) {
     if (first_time) {
       mi->_key = _method_map->size() + 1; // avoid zero key
     }
-    if (method == nullptr) {
+    if (method_id == nullptr) {
       fillNativeMethodInfo(mi, UNKNOWN, nullptr);
     } else if (bci == BCI_ERROR) {
-      fillNativeMethodInfo(mi, (const char *)method, nullptr);
+      fillNativeMethodInfo(mi, (const char *)method_id, nullptr);
     } else if (bci == BCI_NATIVE_FRAME) {
-      const char *name = (const char *)method;
+      const char *name = (const char *)method_id;
       fillNativeMethodInfo(mi, name,
                            Profiler::instance()->getLibraryName(name));
     } else if (bci == BCI_NATIVE_FRAME_REMOTE) {
@@ -575,7 +580,7 @@ MethodInfo *Lookup::resolveMethod(ASGCT_CallFrame &frame) {
       mi->_type = FRAME_NATIVE;
       mi->_is_entry = false;
     } else {
-      fillJavaMethodInfo(mi, method, first_time);
+      fillJavaMethodInfo(mi, method_id, first_time);
     }
   }
 

ddprof-lib/src/main/cpp/flightRecorder.h

@@ -90,27 +90,8 @@ class MethodInfo {
   std::shared_ptr<SharedLineNumberTable> _line_number_table;
   FrameTypeId _type;
 
-  jint getLineNumber(jint bci) {
-    // if the shared pointer is not pointing to the line number table, consider
-    // size 0
-    if (!_line_number_table || _line_number_table->_size == 0) {
-      return 0;
-    }
-
-    int i = 1;
-    while (i < _line_number_table->_size &&
-           bci >= ((jvmtiLineNumberEntry *)_line_number_table->_ptr)[i]
-                      .start_location) {
-      i++;
-    }
-    return ((jvmtiLineNumberEntry *)_line_number_table->_ptr)[i - 1]
-        .line_number;
-  }
-
-  bool isHidden() {
-    // 0x1400 = ACC_SYNTHETIC(0x1000) | ACC_BRIDGE(0x0040)
-    return _modifiers == 0 || (_modifiers & 0x1040);
-  }
+  inline jint getLineNumber(jint bci);
+  inline bool isHidden();
 };
 
 // MethodMap's key can be derived from 3 sources:

ddprof-lib/src/main/cpp/flightRecorder.inline.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright The async-profiler authors
+ * Copyright 2026, Datadog, Inc.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+ #include "flightRecorder.h"
+
+#include "jvmSupport.inline.h"
+
+
+jint MethodInfo::getLineNumber(jint bci) {
+    // if the shared pointer is not pointing to the line number table, consider
+    // size 0
+    if (!_line_number_table || _line_number_table->_size == 0) {
+      return 0;
+    }
+
+    int i = 1;
+    while (i < _line_number_table->_size &&
+           bci >= ((jvmtiLineNumberEntry *)_line_number_table->_ptr)[i]
+                      .start_location) {
+      i++;
+    }
+    return ((jvmtiLineNumberEntry *)_line_number_table->_ptr)[i - 1]
+        .line_number;
+}
+
+bool MethodInfo::isHidden() {
+    return JVMSupport::isHidden(_modifiers);
+}

ddprof-lib/src/main/cpp/frame.h

@@ -1,6 +1,9 @@
 #ifndef _FRAME_H
 #define _FRAME_H
 
+#include <cassert>
+#include "vmEntry.h"
+
 enum FrameTypeId {
   FRAME_INTERPRETED = 0,
   FRAME_JIT_COMPILED = 1,
@@ -10,23 +13,34 @@ enum FrameTypeId {
   FRAME_KERNEL = 5,
   FRAME_C1_COMPILED = 6,
   FRAME_NATIVE_REMOTE = 7,  // Native frame with remote symbolication (build-id + pc-offset)
-  FRAME_TYPE_MAX = FRAME_NATIVE_REMOTE  // Maximum valid frame type
+  FRAME_TYPE_MAX = FRAME_NATIVE_REMOTE,  // Maximum valid frame type
+  FRAME_TYPE_MASK = 0x7
 };
 
 class FrameType {
+  // Maximu size of a single Java method is 64KB of bytecode instructions
+  static constexpr int BCI_MASK = 0xffff;
+  static constexpr int TYPE_SHIFT = 21;
+  static constexpr int ENCODED_MASK = 1 << 20;  // bit indicates that value is encoded
+  static constexpr int RAW_POINTER_MASK = 1 << 30;
 public:
-  static inline int encode(int type, int bci) {
-    return (1 << 24) | (type << 25) | (bci & 0xffffff);
+  static inline int encode(int type, int bci, bool rawPointer = false) {
+    assert((!rawPointer || VM::isHotspot()) && "Raw pointer is only valid for hotspot");
+    return ENCODED_MASK | (type << TYPE_SHIFT) | (bci & BCI_MASK) | (rawPointer ? RAW_POINTER_MASK : 0);
   }
 
   static inline FrameTypeId decode(int bci) {
-    if ((bci >> 24) <= 0) {
-      // Unencoded BCI (bit 24 not set) or negative special BCI values
+    if ((bci & ENCODED_MASK) == 0 || bci < 0) {
+      // Unencoded BCI (ENCODED_SHIFT bit not set) or negative special BCI values
       return FRAME_JIT_COMPILED;
     }
+
     // Clamp to valid FrameTypeId range to defend against corrupted values
-    int raw_type = bci >> 25;
-    return (FrameTypeId)(raw_type <= FRAME_TYPE_MAX ? raw_type : FRAME_TYPE_MAX);
+    return (FrameTypeId)((bci >> TYPE_SHIFT) & FRAME_TYPE_MASK);
+  }
+
+  static inline bool isRawPointer(int bci) {
+    return bci > 0 && (bci & RAW_POINTER_MASK) != 0;
   }
 };