MIPS: Move stack unwinding logic into the runtime.

src/mips/code-stubs-mips.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_MIPS
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 1018 matching lines @@
   isolate->set_fp_stubs_generated(true);
 }
 
 
 void CEntryStub::GenerateAheadOfTime(Isolate* isolate) {
   CEntryStub stub(isolate, 1, kDontSaveFPRegs);
   stub.GetCode();
 }
 
 
+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 v0 to
+  // contain the current pending exception, don't clobber it.
+  ExternalReference find_handler(Runtime::kFindExceptionHandler, isolate);
+  {
+    FrameScope scope(masm, StackFrame::MANUAL);
+    __ PrepareCallCFunction(3, 0, a0);
+    __ mov(a0, zero_reg);
+    __ mov(a1, zero_reg);
+    __ li(a2, Operand(ExternalReference::isolate_address(isolate)));
+    __ CallCFunction(find_handler, 3);
+  }
+
+  // Retrieve the handler context, SP and FP.
+  __ li(cp, Operand(pending_handler_context_address));
+  __ lw(cp, MemOperand(cp));
+  __ li(sp, Operand(pending_handler_sp_address));
+  __ lw(sp, MemOperand(sp));
+  __ li(fp, Operand(pending_handler_fp_address));
+  __ lw(fp, MemOperand(fp));
+
+  // If the handler is a JS frame, restore the context to the frame.
+  // (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
+  // or cp.
+  Label zero;
+  __ Branch(&zero, eq, cp, Operand(zero_reg));
+  __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  __ bind(&zero);
+
+  // Compute the handler entry address and jump to it.
+  __ li(a1, Operand(pending_handler_code_address));
+  __ lw(a1, MemOperand(a1));
+  __ li(a2, Operand(pending_handler_offset_address));
+  __ lw(a2, MemOperand(a2));
+  __ Addu(a1, a1, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ Addu(t9, a1, a2);
+  __ Jump(t9);
+}
+
+
 void CEntryStub::Generate(MacroAssembler* masm) {
   // Called from JavaScript; parameters are on stack as if calling JS function
   // a0: number of arguments including receiver
   // a1: pointer to builtin function
   // fp: frame pointer    (restored after C call)
   // sp: stack pointer    (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
 
   ProfileEntryHookStub::MaybeCallEntryHook(masm);
 
@@ skipping 65 matching lines @@
     __ Branch(&okay, ne, v0, Operand(t0));
     __ stop("The hole escaped");
     __ bind(&okay);
   }
 
   // Check result for exception sentinel.
   Label exception_returned;
   __ LoadRoot(t0, Heap::kExceptionRootIndex);
   __ Branch(&exception_returned, eq, t0, Operand(v0));
 
-  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) {
     Label okay;
+    ExternalReference pending_exception_address(
+        Isolate::kPendingExceptionAddress, isolate());
     __ li(a2, Operand(pending_exception_address));
     __ lw(a2, MemOperand(a2));
     __ LoadRoot(t0, Heap::kTheHoleValueRootIndex);
     // Cannot use check here as it attempts to generate call into runtime.
     __ Branch(&okay, eq, t0, Operand(a2));
     __ stop("Unexpected pending exception");
     __ bind(&okay);
   }
 
   // Exit C frame and return.
   // v0:v1: result
   // sp: stack pointer
   // fp: frame pointer
   // s0: still holds argc (callee-saved).
   __ LeaveExitFrame(save_doubles(), s0, true, EMIT_RETURN);
 
   // Handling of exception.
   __ bind(&exception_returned);
-
-  // Retrieve the pending exception.
-  __ li(a2, Operand(pending_exception_address));
-  __ lw(v0, MemOperand(a2));
-
-  // Clear the pending exception.
-  __ li(a3, Operand(isolate()->factory()->the_hole_value()));
-  __ sw(a3, MemOperand(a2));
-
-  // Special handling of termination exceptions which are uncatchable
-  // by javascript code.
-  Label throw_termination_exception;
-  __ LoadRoot(t0, Heap::kTerminationExceptionRootIndex);
-  __ Branch(&throw_termination_exception, eq, v0, Operand(t0));
-
-  // Handle normal exception.
-  __ Throw(v0);
-
-  __ bind(&throw_termination_exception);
-  __ ThrowUncatchable(v0);
+  ThrowPendingException(masm);
 }
 
 
 void JSEntryStub::Generate(MacroAssembler* masm) {
   Label invoke, handler_entry, exit;
   Isolate* isolate = masm->isolate();
 
   // Registers:
   // a0: entry address
   // a1: function
@@ skipping 1152 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.
   __ li(a1, Operand(isolate()->factory()->the_hole_value()));
   __ li(a2, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
                                       isolate())));
   __ lw(v0, MemOperand(a2, 0));
   __ Branch(&runtime, eq, v0, Operand(a1));
 
-  __ sw(a1, MemOperand(a2, 0));  // Clear pending exception.
-
-  // Check if the exception is a termination. If so, throw as uncatchable.
-  __ LoadRoot(a0, Heap::kTerminationExceptionRootIndex);
-  Label termination_exception;
-  __ Branch(&termination_exception, eq, v0, Operand(a0));
-
-  __ Throw(v0);
-
-  __ bind(&termination_exception);
-  __ ThrowUncatchable(v0);
+  // For exception, throw the exception again.
+  __ EnterExitFrame(false);
+  ThrowPendingException(masm);
 
   __ bind(&failure);
   // For failure and exception return null.
   __ li(v0, Operand(isolate()->factory()->null_value()));
   __ DropAndRet(4);
 
   // Process the result from the native regexp code.
   __ bind(&success);
   __ lw(a1,
          FieldMemOperand(regexp_data, JSRegExp::kIrregexpCaptureCountOffset));
@@ skipping 2879 matching lines @@
                            kStackUnwindSpace, kInvalidStackOffset,
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS