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

src/arm/assembler-arm-inl.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 79 matching lines @@
   DCHECK(index >= 0 && index < NumAllocatableRegisters());
   DCHECK(kScratchDoubleReg.code() - kDoubleRegZero.code() ==
          kNumReservedRegisters - 1);
   if (index >= kDoubleRegZero.code()) {
     return from_code(index + kNumReservedRegisters);
   }
   return from_code(index);
 }
 
 
-void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
+void RelocInfo::apply(intptr_t delta) {
   if (RelocInfo::IsInternalReference(rmode_)) {
     // absolute code pointer inside code object moves with the code object.
     int32_t* p = reinterpret_cast<int32_t*>(pc_);
     *p += delta;  // relocate entry
   }
   // We do not use pc relative addressing on ARM, so there is
   // nothing else to do.
 }
 
 
@@ skipping 154 matching lines @@
 
 void RelocInfo::set_code_age_stub(Code* stub,
                                   ICacheFlushMode icache_flush_mode) {
   DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
   Memory::Address_at(pc_ +
                      (kNoCodeAgeSequenceLength - Assembler::kInstrSize)) =
       stub->instruction_start();
 }
 
 
-Address RelocInfo::call_address() {
+Address RelocInfo::debug_call_address() {
   // The 2 instructions offset assumes patched debug break slot or return
   // sequence.
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return Memory::Address_at(pc_ + 2 * Assembler::kInstrSize);
+  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_ + 2 * Assembler::kInstrSize) = target;
+void RelocInfo::set_debug_call_address(Address target) {
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
+  Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset) =
+      target;
   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_ + 2 * Assembler::kInstrSize);
-}
-
-
 void RelocInfo::WipeOut() {
   DCHECK(IsEmbeddedObject(rmode_) || IsCodeTarget(rmode_) ||
          IsRuntimeEntry(rmode_) || IsExternalReference(rmode_) ||
          IsInternalReference(rmode_));
   if (IsInternalReference(rmode_)) {
     Memory::Address_at(pc_) = NULL;
   } else {
     Assembler::set_target_address_at(pc_, host_, NULL);
   }
 }
@@ skipping 23 matching lines @@
   } 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);
   } 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);
   }
 }
 
 
 Operand::Operand(int32_t immediate, RelocInfo::Mode rmode)  {
   rm_ = no_reg;
   imm32_ = immediate;
@@ skipping 99 matching lines @@
           IsMovImmed(Memory::int32_at(candidate)) &&
           IsOrrImmed(Memory::int32_at(candidate + Assembler::kInstrSize)) &&
           IsOrrImmed(Memory::int32_at(candidate + 2 * Assembler::kInstrSize)) &&
           IsOrrImmed(Memory::int32_at(candidate + 3 * Assembler::kInstrSize)));
     }
     return candidate;
   }
 }
 
 
-Address Assembler::break_address_from_return_address(Address pc) {
-  return pc - Assembler::kPatchDebugBreakSlotReturnOffset;
-}
-
-
 Address Assembler::return_address_from_call_start(Address pc) {
   if (IsLdrPcImmediateOffset(Memory::int32_at(pc)) |
       IsLdrPpImmediateOffset(Memory::int32_at(pc))) {
     // Load from constant pool, small section.
     return pc + kInstrSize * 2;
   } else {
     if (CpuFeatures::IsSupported(ARMv7)) {
       DCHECK(IsMovW(Memory::int32_at(pc)));
       DCHECK(IsMovT(Memory::int32_at(pc + kInstrSize)));
       if (IsLdrPpRegOffset(Memory::int32_at(pc + 2 * kInstrSize))) {
@@ skipping 169 matching lines @@
     if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
       CpuFeatures::FlushICache(pc, 4 * kInstrSize);
     }
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_INL_H_