Fix a throw returning to a frame marked for lazy deopt that captures the stacktrace.

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 367 matching lines @@
 static void GenerateDeoptimizationSequence(Assembler* assembler,
                                            DeoptStubKind kind) {
   // DeoptimizeCopyFrame expects a Dart frame, i.e. EnterDartFrame(0), but there
   // is no need to set the correct PC marker or load PP, since they get patched.
   __ EnterStubFrame();
 
   // The code in this frame may not cause GC. kDeoptimizeCopyFrameRuntimeEntry
   // and kDeoptimizeFillFrameRuntimeEntry are leaf runtime calls.
   const intptr_t saved_result_slot_from_fp =
       kFirstLocalSlotFromFp + 1 - (kNumberOfCpuRegisters - RAX);
+  const intptr_t saved_exception_slot_from_fp =
+      kFirstLocalSlotFromFp + 1 - (kNumberOfCpuRegisters - RAX);
+  const intptr_t saved_stacktrace_slot_from_fp =
+      kFirstLocalSlotFromFp + 1 - (kNumberOfCpuRegisters - RDX);
   // Result in RAX is preserved as part of pushing all registers below.
 
   // Push registers in their enumeration order: lowest register number at
   // lowest address.
   for (intptr_t i = kNumberOfCpuRegisters - 1; i >= 0; i--) {
     if (i == CODE_REG) {
       // Save the original value of CODE_REG pushed before invoking this stub
       // instead of the value used to call this stub.
       __ pushq(Address(RBP, 2 * kWordSize));
     } else {
       __ pushq(static_cast<Register>(i));
     }
   }
   __ subq(RSP, Immediate(kNumberOfXmmRegisters * kFpuRegisterSize));
   intptr_t offset = 0;
   for (intptr_t reg_idx = 0; reg_idx < kNumberOfXmmRegisters; ++reg_idx) {
     XmmRegister xmm_reg = static_cast<XmmRegister>(reg_idx);
     __ movups(Address(RSP, offset), xmm_reg);
     offset += kFpuRegisterSize;
   }
 
   // Pass address of saved registers block.
   __ movq(CallingConventions::kArg1Reg, RSP);
-  __ movq(CallingConventions::kArg2Reg, Immediate(kind == kLazyDeopt ? 1 : 0));
+  bool is_lazy = (kind == kLazyDeoptFromReturn) ||
+                 (kind == kLazyDeoptFromThrow);
+  __ movq(CallingConventions::kArg2Reg, Immediate(is_lazy ? 1 : 0));
   __ ReserveAlignedFrameSpace(0);  // Ensure stack is aligned before the call.
   __ CallRuntime(kDeoptimizeCopyFrameRuntimeEntry, 2);
   // Result (RAX) is stack-size (FP - SP) in bytes.
 
-  const bool preserve_result = (kind == kLazyDeopt);
-  if (preserve_result) {
+  if (kind == kLazyDeoptFromReturn) {
     // Restore result into RBX temporarily.
     __ movq(RBX, Address(RBP, saved_result_slot_from_fp * kWordSize));
+  } else if (kind == kLazyDeoptFromThrow) {
+    // Restore result into RBX temporarily.
+    __ movq(RBX, Address(RBP, saved_exception_slot_from_fp * kWordSize));
+    __ movq(RDX, Address(RBP, saved_stacktrace_slot_from_fp * kWordSize));
   }
 
   // There is a Dart Frame on the stack. We must restore PP and leave frame.
   __ RestoreCodePointer();
   __ LeaveStubFrame();
 
   __ popq(RCX);   // Preserve return address.
   __ movq(RSP, RBP);  // Discard optimized frame.
   __ subq(RSP, RAX);  // Reserve space for deoptimized frame.
   __ pushq(RCX);  // Restore return address.
 
   // DeoptimizeFillFrame expects a Dart frame, i.e. EnterDartFrame(0), but there
   // is no need to set the correct PC marker or load PP, since they get patched.
   __ EnterStubFrame();
 
-  if (preserve_result) {
+  if (kind == kLazyDeoptFromReturn) {
     __ pushq(RBX);  // Preserve result as first local.
+  } else if (kind == kLazyDeoptFromThrow) {
+    __ pushq(RBX);  // Preserve exception as first local.
+    __ pushq(RDX);  // Preserve stacktrace as second local.
   }
   __ ReserveAlignedFrameSpace(0);
   // Pass last FP as a parameter.
   __ movq(CallingConventions::kArg1Reg, RBP);
   __ CallRuntime(kDeoptimizeFillFrameRuntimeEntry, 1);
-  if (preserve_result) {
+  if (kind == kLazyDeoptFromReturn) {
     // Restore result into RBX.
     __ movq(RBX, Address(RBP, kFirstLocalSlotFromFp * kWordSize));
+  } else if (kind == kLazyDeoptFromThrow) {
+    // Restore exception into RBX.
+    __ movq(RBX, Address(RBP, kFirstLocalSlotFromFp * kWordSize));
+    // Restore stacktrace into RDX.
+    __ movq(RDX, Address(RBP, (kFirstLocalSlotFromFp - 1) * kWordSize));
   }
   // Code above cannot cause GC.
   // There is a Dart Frame on the stack. We must restore PP and leave frame.
   __ RestoreCodePointer();
   __ LeaveStubFrame();
 
   // 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.
   // Enter stub frame with loading PP. The caller's PP is not materialized yet.
   __ EnterStubFrame();
-  if (preserve_result) {
+  if (kind == kLazyDeoptFromReturn) {
     __ pushq(RBX);  // Preserve result, it will be GC-d here.
+  } else if (kind == kLazyDeoptFromThrow) {
+    __ pushq(RBX);  // Preserve exception.
+    __ pushq(RDX);  // Preserve stacktrace.
   }
   __ 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) {
+  if (kind == kLazyDeoptFromReturn) {
     __ popq(RAX);  // Restore result.
+  } else if (kind == kLazyDeoptFromThrow) {
+    __ popq(RDX);  // Restore stacktrace.
+    __ popq(RAX);  // Restore exception.
   }
   __ LeaveStubFrame();
 
   __ popq(RCX);  // Pop return address.
   __ addq(RSP, RBX);  // Remove materialization arguments.
   __ pushq(RCX);  // Push return address.
   __ ret();
 }
 
 
 // TOS: return address + call-instruction-size (5 bytes).
 // RAX: result, must be preserved
-void StubCode::GenerateDeoptimizeLazyStub(Assembler* assembler) {
+void StubCode::GenerateDeoptimizeLazyFromReturnStub(Assembler* assembler) {
   // Correct return address to point just after the call that is being
   // deoptimized.
   __ popq(RBX);
+  __ subq(RBX, Immediate(ShortCallPattern::pattern_length_in_bytes()));
+  // Push zap value instead of CODE_REG for lazy deopt.
+  __ pushq(Immediate(0xf1f1f1f1));
+  __ pushq(RBX);
+  GenerateDeoptimizationSequence(assembler, kLazyDeoptFromReturn);
+}
+
+
+// TOS: return address + call-instruction-size (5 bytes).
+// RAX: exception, must be preserved
+// RDX: stacktrace, must be preserved
+void StubCode::GenerateDeoptimizeLazyFromThrowStub(Assembler* assembler) {
+  // Correct return address to point just after the call that is being
+  // deoptimized.
+  __ popq(RBX);
   __ subq(RBX, Immediate(ShortCallPattern::pattern_length_in_bytes()));
   // Push zap value instead of CODE_REG for lazy deopt.
   __ pushq(Immediate(0xf1f1f1f1));
   __ pushq(RBX);
-  GenerateDeoptimizationSequence(assembler, kLazyDeopt);
+  GenerateDeoptimizationSequence(assembler, kLazyDeoptFromThrow);
 }
 
 
 void StubCode::GenerateDeoptimizeStub(Assembler* assembler) {
   GenerateDeoptimizationSequence(assembler, kEagerDeopt);
 }
 
 
 static void GenerateDispatcherCode(Assembler* assembler,
                                    Label* call_target_function) {
@@ skipping 1747 matching lines @@
 }
 
 
 void StubCode::GenerateFrameAwaitingMaterializationStub(Assembler* assembler) {
   __ int3();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64