X87: Move stack unwinding logic into the runtime.

src/x87/code-stubs-x87.cc

Index: src/x87/code-stubs-x87.cc
diff --git a/src/x87/code-stubs-x87.cc b/src/x87/code-stubs-x87.cc
index 5da200d66e8c6b60d66dd9deeaabb10197981820..3d44cc522ed1f0220cc15bbeb8e1c7891e4cdec2 100644
--- a/src/x87/code-stubs-x87.cc
+++ b/src/x87/code-stubs-x87.cc
@@ -865,6 +865,55 @@ void RestParamAccessStub::GenerateNew(MacroAssembler* masm) {
 }
 
 
+static void ThrowPendingException(MacroAssembler* masm) {
+  Isolate* isolate = masm->isolate();
+
+  ExternalReference pending_handler_context_address(
+      Isolate::kPendingHandlerContextAddress, isolate);
+  ExternalReference pending_handler_code_address(
+      Isolate::kPendingHandlerCodeAddress, isolate);
+  ExternalReference pending_handler_offset_address(
+      Isolate::kPendingHandlerOffsetAddress, isolate);
+  ExternalReference pending_handler_fp_address(
+      Isolate::kPendingHandlerFPAddress, isolate);
+  ExternalReference pending_handler_sp_address(
+      Isolate::kPendingHandlerSPAddress, isolate);
+
+  // Ask the runtime for help to determine the handler. This will set eax to
+  // contain the current pending exception, don't clobber it.
+  ExternalReference find_handler(Runtime::kFindExceptionHandler, isolate);
+  {
+    FrameScope scope(masm, StackFrame::MANUAL);
+    __ PrepareCallCFunction(3, eax);
+    __ mov(Operand(esp, 0 * kPointerSize), Immediate(0));  // argc.
+    __ mov(Operand(esp, 1 * kPointerSize), Immediate(0));  // argv.
+    __ mov(Operand(esp, 2 * kPointerSize),
+           Immediate(ExternalReference::isolate_address(isolate)));
+    __ CallCFunction(find_handler, 3);
+  }
+
+  // Retrieve the handler context, SP and FP.
+  __ mov(esi, Operand::StaticVariable(pending_handler_context_address));
+  __ mov(esp, Operand::StaticVariable(pending_handler_sp_address));
+  __ mov(ebp, Operand::StaticVariable(pending_handler_fp_address));
+
+  // If the handler is a JS frame, restore the context to the frame.
+  // (kind == ENTRY) == (ebp == 0) == (esi == 0), so we could test either
+  // ebp or esi.
+  Label skip;
+  __ test(esi, esi);
+  __ j(zero, &skip, Label::kNear);
+  __ mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
+  __ bind(&skip);
+
+  // Compute the handler entry address and jump to it.
+  __ mov(edi, Operand::StaticVariable(pending_handler_code_address));
+  __ mov(edx, Operand::StaticVariable(pending_handler_offset_address));
+  __ lea(edi, FieldOperand(edi, edx, times_1, Code::kHeaderSize));
+  __ jmp(edi);
+}
+
+
 void RegExpExecStub::Generate(MacroAssembler* masm) {
   // Just jump directly to runtime if native RegExp is not selected at compile
   // time or if regexp entry in generated code is turned off runtime switch or
@@ -1146,22 +1195,10 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   __ mov(eax, Operand::StaticVariable(pending_exception));
   __ cmp(edx, eax);
   __ j(equal, &runtime);
-  // For exception, throw the exception again.
 
-  // Clear the pending exception variable.
-  __ mov(Operand::StaticVariable(pending_exception), edx);
-
-  // Special handling of termination exceptions which are uncatchable
-  // by javascript code.
-  __ cmp(eax, factory->termination_exception());
-  Label throw_termination_exception;
-  __ j(equal, &throw_termination_exception, Label::kNear);
-
-  // Handle normal exception by following handler chain.
-  __ Throw(eax);
-
-  __ bind(&throw_termination_exception);
-  __ ThrowUncatchable(eax);
+  // For exception, throw the exception again.
+  __ EnterExitFrame(false);
+  ThrowPendingException(masm);
 
   __ bind(&failure);
   // For failure to match, return null.
@@ -2208,15 +2245,14 @@ void CEntryStub::Generate(MacroAssembler* masm) {
   __ cmp(eax, isolate()->factory()->exception());
   __ j(equal, &exception_returned);
 
-  ExternalReference pending_exception_address(
-      Isolate::kPendingExceptionAddress, isolate());
-
   // Check that there is no pending exception, otherwise we
   // should have returned the exception sentinel.
   if (FLAG_debug_code) {
     __ push(edx);
     __ mov(edx, Immediate(isolate()->factory()->the_hole_value()));
     Label okay;
+    ExternalReference pending_exception_address(
+        Isolate::kPendingExceptionAddress, isolate());
     __ cmp(edx, Operand::StaticVariable(pending_exception_address));
     // Cannot use check here as it attempts to generate call into runtime.
     __ j(equal, &okay, Label::kNear);
@@ -2231,25 +2267,7 @@ void CEntryStub::Generate(MacroAssembler* masm) {
 
   // Handling of exception.
   __ bind(&exception_returned);
-
-  // Retrieve the pending exception.
-  __ mov(eax, Operand::StaticVariable(pending_exception_address));
-
-  // Clear the pending exception.
-  __ mov(edx, Immediate(isolate()->factory()->the_hole_value()));
-  __ mov(Operand::StaticVariable(pending_exception_address), edx);
-
-  // Special handling of termination exceptions which are uncatchable
-  // by javascript code.
-  Label throw_termination_exception;
-  __ cmp(eax, isolate()->factory()->termination_exception());
-  __ j(equal, &throw_termination_exception);
-
-  // Handle normal exception.
-  __ Throw(eax);
-
-  __ bind(&throw_termination_exception);
-  __ ThrowUncatchable(eax);
+  ThrowPendingException(masm);
 }