Store FP instead of SP in the exit info when transitioning from Dart to C++.

runtime/vm/stub_code_arm64.cc

 // Copyright (c) 2014, 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"
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 33 matching lines @@
 
   __ SetPrologueOffset();
   __ Comment("CallToRuntimeStub");
   __ EnterFrame(0);
 
   COMPILE_ASSERT((kAbiPreservedCpuRegs & (1 << R28)) != 0);
   __ LoadIsolate(R28, kNoPP);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to Dart VM C++ code.
-  __ StoreToOffset(SP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
+  __ StoreToOffset(FP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
 
 #if defined(DEBUG)
   { Label ok;
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(R8, R28, Isolate::vm_tag_offset(), kNoPP);
     __ CompareImmediate(R8, VMTag::kDartTagId, kNoPP);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
@@ skipping 79 matching lines @@
   const intptr_t argv_offset = NativeArguments::argv_offset();
   const intptr_t retval_offset = NativeArguments::retval_offset();
 
   __ EnterFrame(0);
 
   COMPILE_ASSERT((kAbiPreservedCpuRegs & (1 << R28)) != 0);
   __ LoadIsolate(R28, kNoPP);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(SP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
+  __ StoreToOffset(FP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
 
 #if defined(DEBUG)
   { Label ok;
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(R6, R28, Isolate::vm_tag_offset(), kNoPP);
     __ CompareImmediate(R6, VMTag::kDartTagId, kNoPP);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
@@ skipping 81 matching lines @@
   const intptr_t argv_offset = NativeArguments::argv_offset();
   const intptr_t retval_offset = NativeArguments::retval_offset();
 
   __ EnterFrame(0);
 
   COMPILE_ASSERT((kAbiPreservedCpuRegs & (1 << R28)) != 0);
   __ LoadIsolate(R28, kNoPP);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(SP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
+  __ StoreToOffset(FP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
 
 #if defined(DEBUG)
   { Label ok;
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(R6, R28, Isolate::vm_tag_offset(), kNoPP);
     __ CompareImmediate(R6, VMTag::kDartTagId, kNoPP);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
@@ skipping 1913 matching lines @@
 // Result:
 //  R1: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, R0, R1, R1);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64