Addition to CodePatcher

runtime/vm/code_patcher_ia32.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
 #include "vm/ic_data.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
 
 namespace dart {
 
 // The pattern of a Dart call is:
 //  1: mov ECX, immediate 1
 //  2: mov EDX, immediate 2
 //  3: call target_address
 //  <- return_address
 class DartCallPattern : public ValueObject {
  public:
   explicit DartCallPattern(uword return_address)
       : start_(return_address - (kNumInstructions * kInstructionSize)) {
-    ASSERT(*reinterpret_cast<uint8_t*>(start_) == 0xB9);
-    ASSERT(*reinterpret_cast<uint8_t*>(start_ + 1 * kInstructionSize) == 0xBA);
-    ASSERT(*reinterpret_cast<uint8_t*>(start_ + 2 * kInstructionSize) == 0xE8);
+    ASSERT(IsValid(return_address));
     ASSERT(kInstructionSize == Assembler::kCallExternalLabelSize);
   }
 
+  static bool IsValid(uword return_address) {
+    uint8_t* code_bytes =
+        reinterpret_cast<uint8_t*>(
+            return_address - (kNumInstructions * kInstructionSize));
+    return (code_bytes[0] == 0xB9) &&
+           (code_bytes[kInstructionSize] == 0xBA) &&
+           (code_bytes[2 * kInstructionSize] == 0xE8);
+  }
+
   uword target() const {
     const uword offset = *reinterpret_cast<uword*>(call_address() + 1);
     return return_address() + offset;
   }
 
   void set_target(uword target) const {
     uword* target_addr = reinterpret_cast<uword*>(call_address() + 1);
     uword offset = target - return_address();
     *target_addr = offset;
     CPU::FlushICache(call_address(), kInstructionSize);
@@ skipping 167 matching lines @@
   for (intptr_t i = 0; i < code.pointer_offsets_length(); i++) {
     const uword addr = code.GetPointerOffsetAt(i) + code.EntryPoint();
     if (addr < limit) {
       return false;
     }
   }
   return true;
 }
 
 
+bool CodePatcher::IsDartCall(uword return_address) {
+  return DartCallPattern::IsValid(return_address);
+}
+
+
 void CodePatcher::GetInstanceCallAt(uword return_address,
                                     String* function_name,
                                     int* num_arguments,
                                     int* num_named_arguments,
                                     uword* target) {
   ASSERT(function_name != NULL);
   ASSERT(num_arguments != NULL);
   ASSERT(num_named_arguments != NULL);
   ASSERT(target != NULL);
   InstanceCall call(return_address);
@@ skipping 18 matching lines @@
 }
 
 
 intptr_t CodePatcher::InstanceCallSizeInBytes() {
   return DartCallPattern::kNumInstructions * DartCallPattern::kInstructionSize;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32