Move stack unwinding logic into the runtime.

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 1166 matching lines @@
   __ mov(Operand(esp, 2 * kPointerSize), ecx);
   __ lea(edx, Operand(edx, ecx, times_2,
                       StandardFrameConstants::kCallerSPOffset));
   __ mov(Operand(esp, 3 * kPointerSize), edx);
 
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kNewRestParam, 3, 1);
 }
 
 
+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);
+  __ 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)));
+  __ mov(ebx, Immediate(find_handler));
+  __ call(ebx);
+
+  // 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
   // at compilation.
 #ifdef V8_INTERPRETED_REGEXP
   __ TailCallRuntime(Runtime::kRegExpExecRT, 4, 1);
 #else  // V8_INTERPRETED_REGEXP
 
   // Stack frame on entry.
   //  esp[0]: return address
@@ skipping 261 matching lines @@
   // Result must now be exception. If there is no pending exception already a
   // stack overflow (on the backtrack stack) was detected in RegExp code but
   // haven't created the exception yet. Handle that in the runtime system.
   // TODO(592): Rerunning the RegExp to get the stack overflow exception.
   ExternalReference pending_exception(Isolate::kPendingExceptionAddress,
                                       isolate());
   __ mov(edx, Immediate(isolate()->factory()->the_hole_value()));
   __ 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);
+  ThrowPendingException(masm);

[Jarin, 2015/02/27 07:49:14]

Out of curiosity, how is the uncatchable exception handled in the new world?

 
   __ bind(&failure);
   // For failure to match, return null.
   __ mov(eax, factory->null_value());
   __ ret(4 * kPointerSize);
 
   // Load RegExp data.
   __ bind(&success);
   __ mov(eax, Operand(esp, kJSRegExpOffset));
   __ mov(ecx, FieldOperand(eax, JSRegExp::kDataOffset));
@@ skipping 1014 matching lines @@
     __ j(not_equal, &okay, Label::kNear);
     __ int3();
     __ bind(&okay);
   }
 
   // Check result for exception sentinel.
   Label exception_returned;
   __ 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);
     __ int3();
     __ bind(&okay);
     __ pop(edx);
   }
 
   // Exit the JavaScript to C++ exit frame.
   __ LeaveExitFrame(save_doubles());
   __ ret(0);
 
   // 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);
 }
 
 
 void JSEntryStub::Generate(MacroAssembler* masm) {
   Label invoke, handler_entry, exit;
   Label not_outermost_js, not_outermost_js_2;
 
   ProfileEntryHookStub::MaybeCallEntryHook(masm);
 
   // Set up frame.
@@ skipping 2568 matching lines @@
                            ApiParameterOperand(2), kStackSpace, nullptr,
                            Operand(ebp, 7 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32