Support for return-address rewriting profilers.

src/frames.cc

Index: src/frames.cc
diff --git a/src/frames.cc b/src/frames.cc
index 40df12c437281bb6006c66af0e8a55871c14623d..81b75c889e326af68a6630032debab2c57c1a0bd 100644
--- a/src/frames.cc
+++ b/src/frames.cc
@@ -41,6 +41,22 @@
 namespace v8 {
 namespace internal {
 
+
+ReturnAddressLocationResolver return_address_location_resolver = NULL;

[Vyacheslav Egorov (Chromium), 2012/02/24 10:34:02]

declare it static

[Sigurður Ásgeirsson, 2012/02/24 14:46:04]

Done.

+
+
+// Resolves pc_address through the resolution address function if one is set.
+Address* ResolveReturnAddressLocation(Address* pc_address) {

[Vyacheslav Egorov (Chromium), 2012/02/24 10:34:02]

declare it static

[Sigurður Ásgeirsson, 2012/02/24 14:46:04]

Done.
Does this warrant "static inline" or are the compilers we use generally smart
enough to work that out for themselves?

[Vyacheslav Egorov (Chromium), 2012/02/24 14:48:21]

Yes, I think there is no harm declaring it inline (though these days it serves
more as a way to communicate our "hope of inlining" to other code readers than
to compiler).

[Sigurður Ásgeirsson, 2012/02/24 14:59:40]

Done.

+  if (return_address_location_resolver == NULL) {
+    return pc_address;
+  } else {
+    return reinterpret_cast<Address*>(
+        return_address_location_resolver(
+            reinterpret_cast<uintptr_t>(pc_address)));
+	}
+}
+
+
 // Iterator that supports traversing the stack handlers of a
 // particular frame. Needs to know the top of the handler chain.
 class StackHandlerIterator BASE_EMBEDDED {
@@ -155,8 +171,8 @@ void StackFrameIterator::Reset() {
     ASSERT(fp_ != NULL);
     state.fp = fp_;
     state.sp = sp_;
-    state.pc_address =
-        reinterpret_cast<Address*>(StandardFrame::ComputePCAddress(fp_));
+    state.pc_address = ResolveReturnAddressLocation(
+        reinterpret_cast<Address*>(StandardFrame::ComputePCAddress(fp_)));
     type = StackFrame::ComputeType(isolate(), &state);
   }
   if (SingletonFor(type) == NULL) return;
@@ -413,6 +429,11 @@ void StackFrame::IteratePc(ObjectVisitor* v,
   }
 }
 

[Vyacheslav Egorov (Chromium), 2012/02/24 10:34:02]

add empty line

[Sigurður Ásgeirsson, 2012/02/24 14:46:04]

Done.

+void StackFrame::SetReturnAddressLocationResolver(
+    ReturnAddressLocationResolver resolver) {
+  return_address_location_resolver = resolver;

[Vyacheslav Egorov (Chromium), 2012/02/24 10:34:02]

assert that we don't have any other resolver installed.

[Sigurður Ásgeirsson, 2012/02/24 14:46:04]

Done.

+}
+
 
 StackFrame::Type StackFrame::ComputeType(Isolate* isolate, State* state) {
   ASSERT(state->fp != NULL);
@@ -488,8 +509,8 @@ void ExitFrame::ComputeCallerState(State* state) const {
   // Set up the caller state.
   state->sp = caller_sp();
   state->fp = Memory::Address_at(fp() + ExitFrameConstants::kCallerFPOffset);
-  state->pc_address
-      = reinterpret_cast<Address*>(fp() + ExitFrameConstants::kCallerPCOffset);
+  state->pc_address = ResolveReturnAddressLocation(
+      reinterpret_cast<Address*>(fp() + ExitFrameConstants::kCallerPCOffset));
 }
 
 
@@ -523,7 +544,8 @@ StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {
 void ExitFrame::FillState(Address fp, Address sp, State* state) {
   state->sp = sp;
   state->fp = fp;
-  state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
+  state->pc_address = ResolveReturnAddressLocation(
+      reinterpret_cast<Address*>(sp - 1 * kPointerSize));
 }
 
 
@@ -558,7 +580,8 @@ int StandardFrame::ComputeExpressionsCount() const {
 void StandardFrame::ComputeCallerState(State* state) const {
   state->sp = caller_sp();
   state->fp = caller_fp();
-  state->pc_address = reinterpret_cast<Address*>(ComputePCAddress(fp()));
+  state->pc_address = ResolveReturnAddressLocation(
+      reinterpret_cast<Address*>(ComputePCAddress(fp())));
 }