Avoiding the assumption that the pc pointer of RelocInfo points to the word...

Avoiding the assumption that the pc pointer of RelocInfo points to the word containing the target address. It wasn't true for ARM. (One step closer to serialization on ARM).
Review URL: http://codereview.chromium.org/17376

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1067 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/assembler-arm-inl.h

@@ -61,13 +61,19 @@ void RelocInfo::apply(int delta) {
 
 
 Address RelocInfo::target_address() {
-  ASSERT(IsCodeTarget(rmode_));
+  ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
   return Assembler::target_address_at(pc_);
 }
 
 
+Address RelocInfo::target_address_address() {
+  ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
+  return reinterpret_cast<Address>(Assembler::target_address_address_at(pc_));
+}
+
+
 void RelocInfo::set_target_address(Address target) {
-  ASSERT(IsCodeTarget(rmode_));
+  ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
   Assembler::set_target_address_at(pc_, target);
 }
 
@@ -92,7 +98,7 @@ void RelocInfo::set_target_object(Object* target) {
 
 Address* RelocInfo::target_reference_address() {
   ASSERT(rmode_ == EXTERNAL_REFERENCE);
-  return reinterpret_cast<Address*>(pc_);
+  return reinterpret_cast<Address*>(Assembler::target_address_address_at(pc_));
 }
 
 

src/assembler-ia32-inl.h

@@ -70,6 +70,12 @@ Address RelocInfo::target_address() {
 }
 
 
+Address RelocInfo::target_address_address() {
+  ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
+  return reinterpret_cast<Address>(pc_);
+}
+
+
 void RelocInfo::set_target_address(Address target) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
   Assembler::set_target_address_at(pc_, target);

src/assembler.h

@@ -230,14 +230,19 @@ class RelocInfo BASE_EMBEDDED {
   // Apply a relocation by delta bytes
   INLINE(void apply(int delta));
 
-  // Read/modify the code target in the branch/call instruction this relocation
-  // applies to; can only be called if IsCodeTarget(rmode_)
+  // Read/modify the code target in the branch/call instruction
+  // this relocation applies to;
+  // can only be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY
   INLINE(Address target_address());
   INLINE(void set_target_address(Address target));
   INLINE(Object* target_object());
   INLINE(Object** target_object_address());
   INLINE(void set_target_object(Object* target));
 
+  // Read the address of the word containing the target_address. Can only
+  // be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY.
+  INLINE(Address target_address_address());
+
   // Read/modify the reference in the instruction this relocation
   // applies to; can only be called if rmode_ is external_reference
   INLINE(Address* target_reference_address());

src/serialize.cc

@@ -586,29 +586,33 @@ ExternalReferenceTable::ExternalReferenceTable() : refs_(64) {
       UNCLASSIFIED,
       3,
       "StackGuard::address_of_limit()");
-  Add(ExternalReference::debug_break().address(),
+  Add(ExternalReference::address_of_regexp_stack_limit().address(),
       UNCLASSIFIED,
       4,
+      "RegExpStack::limit_address()");
+  Add(ExternalReference::debug_break().address(),
+      UNCLASSIFIED,
+      5,
       "Debug::Break()");
   Add(ExternalReference::new_space_start().address(),
       UNCLASSIFIED,
-      5,
+      6,
       "Heap::NewSpaceStart()");
   Add(ExternalReference::heap_always_allocate_scope_depth().address(),
       UNCLASSIFIED,
-      6,
+      7,
       "Heap::always_allocate_scope_depth()");
   Add(ExternalReference::new_space_allocation_limit_address().address(),
       UNCLASSIFIED,
-      7,
+      8,
       "Heap::NewSpaceAllocationLimitAddress()");
   Add(ExternalReference::new_space_allocation_top_address().address(),
       UNCLASSIFIED,
-      8,
+      9,
       "Heap::NewSpaceAllocationTopAddress()");
   Add(ExternalReference::debug_step_in_fp_address().address(),
       UNCLASSIFIED,
-      9,
+      10,
       "Debug::step_in_fp_addr()");
 }
 
@@ -804,7 +808,7 @@ class ReferenceUpdater: public ObjectVisitor {
     Address target = rinfo->target_address();
     uint32_t encoding = reference_encoder_->Encode(target);
     CHECK(target == NULL ? encoding == 0 : encoding != 0);
-    offsets_.Add(reinterpret_cast<Address>(rinfo->pc()) - obj_address_);
+    offsets_.Add(rinfo->target_address_address() - obj_address_);
     addresses_.Add(reinterpret_cast<Address>(encoding));
   }
 
@@ -1269,7 +1273,7 @@ void Deserializer::VisitExternalReferences(Address* start, Address* end) {
 
 
 void Deserializer::VisitRuntimeEntry(RelocInfo* rinfo) {
-  uint32_t* pc = reinterpret_cast<uint32_t*>(rinfo->pc());
+  uint32_t* pc = reinterpret_cast<uint32_t*>(rinfo->target_address_address());
   uint32_t encoding = *pc;
   Address target = reference_decoder_->Decode(encoding);
   rinfo->set_target_address(target);

test/cctest/test-serialize.cc

@@ -109,9 +109,9 @@ TEST(ExternalReferenceEncoder) {
       ExternalReference::address_of_stack_guard_limit();
   CHECK_EQ(make_code(UNCLASSIFIED, 3),
            encoder.Encode(stack_guard_limit_address.address()));
-  CHECK_EQ(make_code(UNCLASSIFIED, 4),
-           encoder.Encode(ExternalReference::debug_break().address()));
   CHECK_EQ(make_code(UNCLASSIFIED, 5),
+           encoder.Encode(ExternalReference::debug_break().address()));
+  CHECK_EQ(make_code(UNCLASSIFIED, 6),
            encoder.Encode(ExternalReference::new_space_start().address()));
 }
 
@@ -141,9 +141,9 @@ TEST(ExternalReferenceDecoder) {
   CHECK_EQ(ExternalReference::address_of_stack_guard_limit().address(),
            decoder.Decode(make_code(UNCLASSIFIED, 3)));
   CHECK_EQ(ExternalReference::debug_break().address(),
-           decoder.Decode(make_code(UNCLASSIFIED, 4)));
-  CHECK_EQ(ExternalReference::new_space_start().address(),
            decoder.Decode(make_code(UNCLASSIFIED, 5)));
+  CHECK_EQ(ExternalReference::new_space_start().address(),
+           decoder.Decode(make_code(UNCLASSIFIED, 6)));
 }