Temporary fix for Bug 14790 Use EnterStubFrameWithPP for breakpoint handler stubs that have result …

runtime/vm/stub_code_x64.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_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 435 matching lines @@
   // Code above cannot cause GC.
   // There is a Dart Frame on the stack. We just need the PP.
   __ movq(PP, Address(RBP, -2 * kWordSize));
   __ LeaveFrame();
 
   // Frame is fully rewritten at this point and it is safe to perform a GC.
   // Materialize any objects that were deferred by FillFrame because they
   // require allocation.
   __ EnterStubFrame();
   if (preserve_result) {
+    __ pushq(Immediate(0));  // Workaround for dropped stack slot during GC.
     __ pushq(RBX);  // Preserve result, it will be GC-d here.
   }
   __ pushq(Immediate(Smi::RawValue(0)));  // Space for the result.
   __ CallRuntime(kDeoptimizeMaterializeRuntimeEntry, 0);
   // Result tells stub how many bytes to remove from the expression stack
   // of the bottom-most frame. They were used as materialization arguments.
   __ popq(RBX);
   __ SmiUntag(RBX);
   if (preserve_result) {
     __ popq(RAX);  // Restore result.
+    __ Drop(1);  // Workaround for dropped stack slot during GC.
   }
   __ LeaveFrame();
 
   __ popq(RCX);  // Pop return address.
   __ addq(RSP, RBX);  // Remove materialization arguments.
   __ pushq(RCX);  // Push return address.
   __ ret();
 }
 
 
@@ skipping 1337 matching lines @@
   __ popq(RCX);  // Restore IC data array.
   __ popq(RDX);  // Restore arguments descriptor array.
   __ LeaveFrame();
   __ ret();
 }
 
 
 //  RBX, R10: May contain arguments to runtime stub.
 //  TOS(0): return address (Dart code).
 void StubCode::GenerateBreakpointRuntimeStub(Assembler* assembler) {
-  __ EnterStubFrame();
+  __ EnterStubFrameWithPP();
   // Preserve runtime args.
   __ pushq(RBX);
   __ pushq(R10);
   // Room for result. Debugger stub returns address of the
   // unpatched runtime stub.
   __ LoadObject(R12, Object::null_object(), PP);
   __ pushq(R12);  // Room for result.
   __ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
   __ popq(RAX);  // Address of original.
   __ popq(R10);  // Restore arguments.
   __ popq(RBX);
-  __ LeaveFrame();
+  __ LeaveFrameWithPP();
   __ jmp(RAX);   // Jump to original stub.
 }
 
 
 //  RBX: ICData (unoptimized static call)
 //  TOS(0): return address (Dart code).
 void StubCode::GenerateBreakpointStaticStub(Assembler* assembler) {
   __ EnterStubFrame();
   __ LoadObject(R12, Object::null_object(), PP);
   __ pushq(RBX);  // Preserve IC data for unoptimized call.
   __ pushq(R12);  // Room for result.
   __ CallRuntime(kBreakpointStaticHandlerRuntimeEntry, 0);
   __ popq(RAX);  // Code object.
   __ popq(RBX);  // Restore IC data.
   __ LeaveFrame();
 
   // Load arguments descriptor into R10.
   __ movq(R10, FieldAddress(RBX, ICData::arguments_descriptor_offset()));
   // Now call the static function. The breakpoint handler function
   // ensures that the call target is compiled.
   __ movq(RBX, FieldAddress(RAX, Code::instructions_offset()));
   __ addq(RBX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
   __ jmp(RBX);
 }
 
 
 //  TOS(0): return address (Dart code).
 void StubCode::GenerateBreakpointReturnStub(Assembler* assembler) {
-  __ EnterStubFrame();
+  __ EnterStubFrameWithPP();
   __ pushq(RAX);
   __ CallRuntime(kBreakpointReturnHandlerRuntimeEntry, 0);
   __ popq(RAX);
-  __ LeaveFrame();
+  __ LeaveFrameWithPP();
 
   __ popq(R11);  // discard return address of call to this stub.
   __ LeaveFrameWithPP();
   __ ret();
 }
 
 
 //  RBX: Inline cache data array.
 //  TOS(0): return address (Dart code).
 void StubCode::GenerateBreakpointDynamicStub(Assembler* assembler) {
@@ skipping 290 matching lines @@
   __ movq(right, Address(RSP, 3 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ popq(right);
   __ popq(left);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64