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

src/mips/assembler-mips-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 99 matching lines @@
   DCHECK(reg.is_valid());
   DCHECK(!reg.is(kDoubleRegZero));
   DCHECK(!reg.is(kLithiumScratchDouble));
   return (reg.code() / 2);
 }
 
 
 // -----------------------------------------------------------------------------
 // RelocInfo.
 
-void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
+void RelocInfo::apply(intptr_t delta) {
   if (IsCodeTarget(rmode_)) {
     uint32_t scope1 = (uint32_t) target_address() & ~kImm28Mask;
     uint32_t scope2 = reinterpret_cast<uint32_t>(pc_) & ~kImm28Mask;
 
     if (scope1 != scope2) {
       Assembler::JumpToJumpRegister(pc_);
     }
   }
   if (IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_)) {
     // Absolute code pointer inside code object moves with the code object.
@@ skipping 57 matching lines @@
         host(), this, HeapObject::cast(target_code));
   }
 }
 
 
 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;
-}
-
-
 void Assembler::set_target_internal_reference_encoded_at(Address pc,
                                                          Address target) {
   // Encoded internal references are lui/ori load of 32-bit abolute address.
   Instr instr_lui = Assembler::instr_at(pc + 0 * Assembler::kInstrSize);
   Instr instr_ori = Assembler::instr_at(pc + 1 * Assembler::kInstrSize);
   DCHECK(Assembler::IsLui(instr_lui));
   DCHECK(Assembler::IsOri(instr_ori));
   instr_lui &= ~kImm16Mask;
   instr_ori &= ~kImm16Mask;
   int32_t imm = reinterpret_cast<int32_t>(target);
@@ skipping 139 matching lines @@
 
 void RelocInfo::set_code_age_stub(Code* stub,
                                   ICacheFlushMode icache_flush_mode) {
   DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
   Assembler::set_target_address_at(pc_ + Assembler::kInstrSize,
                                    host_,
                                    stub->instruction_start());
 }
 
 
-Address RelocInfo::call_address() {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
+Address RelocInfo::debug_call_address() {
   // The pc_ offset of 0 assumes mips patched return sequence per
   // debug-mips.cc BreakLocation::SetDebugBreakAtReturn(), or
   // debug break slot per BreakLocation::SetDebugBreakAtSlot().
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
   return Assembler::target_address_at(pc_, host_);
 }
 
 
-void RelocInfo::set_call_address(Address target) {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
+void RelocInfo::set_debug_call_address(Address target) {
+  DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
   // The pc_ offset of 0 assumes mips patched return sequence per
   // debug-mips.cc BreakLocation::SetDebugBreakAtReturn(), or

[paul.l..., 2015/07/14 19:15:59]

comment nit: remove mention of deleted function
BreakLocation::SetDebugBreakAtReturn()

[balazs.kilvady, 2015/07/14 19:30:22]

Done.

   // debug break slot per BreakLocation::SetDebugBreakAtSlot().
   Assembler::set_target_address_at(pc_, host_, 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();
-}
-
-
-Object** RelocInfo::call_object_address() {
-  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
-         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
-  return reinterpret_cast<Object**>(pc_ + 2 * Assembler::kInstrSize);
-}
-
-
-void RelocInfo::set_call_object(Object* target) {
-  *call_object_address() = target;
-}
-
-
 void RelocInfo::WipeOut() {
   DCHECK(IsEmbeddedObject(rmode_) || IsCodeTarget(rmode_) ||
          IsRuntimeEntry(rmode_) || IsExternalReference(rmode_) ||
          IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_));
   if (IsInternalReference(rmode_)) {
     Memory::Address_at(pc_) = NULL;
   } else if (IsInternalReferenceEncoded(rmode_)) {
     Assembler::set_target_internal_reference_encoded_at(pc_, nullptr);
   } else {
     Assembler::set_target_address_at(pc_, host_, NULL);
@@ skipping 28 matching lines @@
     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 ||
              mode == RelocInfo::INTERNAL_REFERENCE_ENCODED) {
     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 ||
              mode == RelocInfo::INTERNAL_REFERENCE_ENCODED) {
     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);
   }
 }
 
 
 // -----------------------------------------------------------------------------
 // Assembler.
 
@@ skipping 18 matching lines @@
   }
   *reinterpret_cast<Instr*>(pc_) = x;
   pc_ += kInstrSize;
   CheckTrampolinePoolQuick();
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_MIPS_ASSEMBLER_MIPS_INL_H_