Debugger: use debug break slots to break at function exit.

src/x64/assembler-x64-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_X64_ASSEMBLER_X64_INL_H_
 #define V8_X64_ASSEMBLER_X64_INL_H_
 
 #include "src/x64/assembler-x64.h"
 
 #include "src/base/cpu.h"
@@ skipping 275 matching lines @@
     Address pc, Address target, RelocInfo::Mode mode) {
   Memory::Address_at(pc) = target;
 }
 
 
 Address Assembler::target_address_from_return_address(Address pc) {
   return pc - kCallTargetAddressOffset;
 }
 
 
-Address Assembler::break_address_from_return_address(Address pc) {
-  return pc - Assembler::kPatchDebugBreakSlotReturnOffset;
-}
-
-
 Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
   return code_targets_[Memory::int32_at(pc)];
 }
 
 
 Address Assembler::runtime_entry_at(Address pc) {
   return Memory::int32_at(pc) + isolate()->code_range()->start();
 }
 
 // -----------------------------------------------------------------------------
 // Implementation of RelocInfo
 
 // The modes possibly affected by apply must be in kApplyMask.
 void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
   bool flush_icache = icache_flush_mode != SKIP_ICACHE_FLUSH;
-  if (IsInternalReference(rmode_)) {
+  if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
+    Memory::int32_at(pc_) -= static_cast<int32_t>(delta);
+    if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(int32_t));
+  } else if (IsCodeAgeSequence(rmode_)) {
+    if (*pc_ == kCallOpcode) {
+      int32_t* p = reinterpret_cast<int32_t*>(pc_ + 1);
+      *p -= static_cast<int32_t>(delta);  // Relocate entry.
+      if (flush_icache) CpuFeatures::FlushICache(p, sizeof(int32_t));
+    }
+  } else if (IsInternalReference(rmode_)) {
     // absolute code pointer inside code object moves with the code object.
     Memory::Address_at(pc_) += delta;
     if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(Address));
-  } else if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
-    Memory::int32_at(pc_) -= static_cast<int32_t>(delta);
-    if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(int32_t));
-  } else if (rmode_ == CODE_AGE_SEQUENCE) {
-    if (*pc_ == kCallOpcode) {
-      int32_t* p = reinterpret_cast<int32_t*>(pc_ + 1);
-      *p -= static_cast<int32_t>(delta);  // Relocate entry.
-      if (flush_icache) CpuFeatures::FlushICache(p, sizeof(uint32_t));
-    }
   }
 }
 
 
 Address RelocInfo::target_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
   return Assembler::target_address_at(pc_, host_);
 }
 
 
@@ skipping 180 matching lines @@
 
 void RelocInfo::set_code_age_stub(Code* stub,
                                   ICacheFlushMode icache_flush_mode) {
   DCHECK(*pc_ == kCallOpcode);
   DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
   Assembler::set_target_address_at(pc_ + 1, host_, stub->instruction_start(),
                                    icache_flush_mode);
 }
 
 
-Address RelocInfo::call_address() {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return Memory::Address_at(
-      pc_ + Assembler::kRealPatchReturnSequenceAddressOffset);
+Address RelocInfo::debug_call_address() {
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
+  return Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset);
 }
 
 
-void RelocInfo::set_call_address(Address target) {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  Memory::Address_at(pc_ + Assembler::kRealPatchReturnSequenceAddressOffset) =
+void RelocInfo::set_debug_call_address(Address target) {
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
+  Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset) =
       target;
-  CpuFeatures::FlushICache(
-      pc_ + Assembler::kRealPatchReturnSequenceAddressOffset, sizeof(Address));
+  CpuFeatures::FlushICache(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset,
+                           sizeof(Address));
   if (host() != NULL) {
     Object* target_code = Code::GetCodeFromTargetAddress(target);
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
         host(), this, HeapObject::cast(target_code));
   }
 }
 
 
-Object* RelocInfo::call_object() {
-  return *call_object_address();
-}
-
-
-void RelocInfo::set_call_object(Object* target) {
-  *call_object_address() = target;
-}
-
-
-Object** RelocInfo::call_object_address() {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return reinterpret_cast<Object**>(
-      pc_ + Assembler::kPatchReturnSequenceAddressOffset);
-}
-
-
 void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
     visitor->VisitEmbeddedPointer(this);
     CpuFeatures::FlushICache(pc_, sizeof(Address));
   } else if (RelocInfo::IsCodeTarget(mode)) {
     visitor->VisitCodeTarget(this);
   } else if (mode == RelocInfo::CELL) {
     visitor->VisitCell(this);
   } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
     visitor->VisitExternalReference(this);
   } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
     visitor->VisitInternalReference(this);
   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
     visitor->VisitCodeAgeSequence(this);
-  } else if (((RelocInfo::IsJSReturn(mode) &&
-              IsPatchedReturnSequence()) ||
-             (RelocInfo::IsDebugBreakSlot(mode) &&
-              IsPatchedDebugBreakSlotSequence())) &&
+  } else if (RelocInfo::IsDebugBreakSlot(mode) &&
+             IsPatchedDebugBreakSlotSequence() &&
              isolate->debug()->has_break_points()) {
     visitor->VisitDebugTarget(this);
   } else if (RelocInfo::IsRuntimeEntry(mode)) {
     visitor->VisitRuntimeEntry(this);
   }
 }
 
 
 template<typename StaticVisitor>
 void RelocInfo::Visit(Heap* heap) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
     StaticVisitor::VisitEmbeddedPointer(heap, this);
     CpuFeatures::FlushICache(pc_, sizeof(Address));
   } else if (RelocInfo::IsCodeTarget(mode)) {
     StaticVisitor::VisitCodeTarget(heap, this);
   } else if (mode == RelocInfo::CELL) {
     StaticVisitor::VisitCell(heap, this);
   } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
     StaticVisitor::VisitExternalReference(this);
   } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
     StaticVisitor::VisitInternalReference(this);
   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
     StaticVisitor::VisitCodeAgeSequence(heap, this);
   } else if (heap->isolate()->debug()->has_break_points() &&
-             ((RelocInfo::IsJSReturn(mode) &&
-              IsPatchedReturnSequence()) ||
-             (RelocInfo::IsDebugBreakSlot(mode) &&
-              IsPatchedDebugBreakSlotSequence()))) {
+             RelocInfo::IsDebugBreakSlot(mode) &&
+             IsPatchedDebugBreakSlotSequence()) {
     StaticVisitor::VisitDebugTarget(heap, this);
   } else if (RelocInfo::IsRuntimeEntry(mode)) {
     StaticVisitor::VisitRuntimeEntry(this);
   }
 }
 
 
 // -----------------------------------------------------------------------------
 // Implementation of Operand
 
@@ skipping 33 matching lines @@
 
 void Operand::set_disp64(int64_t disp) {
   DCHECK_EQ(1, len_);
   int64_t* p = reinterpret_cast<int64_t*>(&buf_[len_]);
   *p = disp;
   len_ += sizeof(disp);
 }
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_INL_H_