Fast-codegen: Implementing try/finally on top of nesting context.

src/arm/fast-codegen-arm.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1629 matching lines @@
       __ LoadRoot(ip, Heap::kFalseValueRootIndex);
       __ push(ip);
       __ jmp(saved_false);
       break;
   }
   true_label_ = saved_true;
   false_label_ = saved_false;
   // Convert current context to test context: End post-test code.
 }
 
+
 void FastCodeGenerator::VisitThisFunction(ThisFunction* expr) {
   __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   Move(expr->context(), r0);
 }
 
 
 Register FastCodeGenerator::result_register() { return r0; }
 
+// ----------------------------------------------------------------------------
+// Non-local control flow support.
+
+void FastCodeGenerator::EnterFinallyBlock() {
+  // Cook return address in link register to stack (smi encoded Code* delta)
+  __ sub(r1, lr, Operand(masm_->CodeObject()));
+  ASSERT_EQ(1, kSmiTagSize + kSmiShiftSize);
+  ASSERT_EQ(0, kSmiTag);
+  __ add(r1, r1, Operand(r1));  // Convert to smi.
+  __ push(r1);
+  // Store result register while executing finally block.
+  __ push(r0);
+}
+
+
+void FastCodeGenerator::ReturnFromFinallyBlock() {
+  // Restore result register from stack.
+  __ pop(r0);
+  // Uncook return address and return.
+  __ pop(r1);
+  ASSERT_EQ(1, kSmiTagSize + kSmiShiftSize);
+  __ mov(r1, Operand(r1, ASR, 1));  // Un-smi-tag value.
+  __ add(pc, r1, Operand(masm_->CodeObject()));
+}
+
+
+void FastCodeGenerator::ThrowException() {
+  __ push(r0);
+  __ CallRuntime(Runtime::kThrow, 1);
+}
+
+
 #undef __
 
-
 } }  // namespace v8::internal