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

runtime/vm/stub_code_arm.cc

 // Copyright (c) 2013, 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_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 34 matching lines @@
 
   __ mov(IP, Operand(0));
   __ Push(IP);  // Push 0 for the PC marker.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
   COMPILE_ASSERT((kAbiPreservedCpuRegs & (1 << R9)) != 0);
   __ LoadIsolate(R9);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to Dart VM C++ code.
-  __ StoreToOffset(kWord, SP, R9, Isolate::top_exit_frame_info_offset());
+  __ StoreToOffset(kWord, FP, R9, Isolate::top_exit_frame_info_offset());
 
 #if defined(DEBUG)
   { Label ok;
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(kWord, R6, R9, Isolate::vm_tag_offset());
     __ CompareImmediate(R6, VMTag::kDartTagId);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
@@ skipping 78 matching lines @@
 
   __ mov(IP, Operand(0));
   __ Push(IP);  // Push 0 for the PC marker.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
   COMPILE_ASSERT((kAbiPreservedCpuRegs & (1 << R9)) != 0);
   __ LoadIsolate(R9);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(kWord, SP, R9, Isolate::top_exit_frame_info_offset());
+  __ StoreToOffset(kWord, FP, R9, Isolate::top_exit_frame_info_offset());
 
 #if defined(DEBUG)
   { Label ok;
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(kWord, R6, R9, Isolate::vm_tag_offset());
     __ CompareImmediate(R6, VMTag::kDartTagId);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
@@ skipping 72 matching lines @@
 
   __ mov(IP, Operand(0));
   __ Push(IP);  // Push 0 for the PC marker.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
   COMPILE_ASSERT((kAbiPreservedCpuRegs & (1 << R9)) != 0);
   __ LoadIsolate(R9);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(kWord, SP, R9, Isolate::top_exit_frame_info_offset());
+  __ StoreToOffset(kWord, FP, R9, Isolate::top_exit_frame_info_offset());
 
 #if defined(DEBUG)
   { Label ok;
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(kWord, R6, R9, Isolate::vm_tag_offset());
     __ CompareImmediate(R6, VMTag::kDartTagId);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
@@ skipping 1872 matching lines @@
 // Result:
 //  R1: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, R0, R1, R1);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM