Ensure stack alignment in ARM port...

src/arm/simulator-arm.cc

 // Copyright 2010 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 1231 matching lines @@
                                          int32_t arg2,
                                          int32_t arg3);
 
 
 // Software interrupt instructions are used by the simulator to call into the
 // C-based V8 runtime.
 void Simulator::SoftwareInterrupt(Instr* instr) {
   int swi = instr->SwiField();
   switch (swi) {
     case call_rt_redirected: {
+      // Check if stack is aligned. Error if not aligned is reported below to
+      // include information on the function called.
+      bool stack_aligned =
+          (get_register(sp)
+           & (::v8::internal::FLAG_sim_stack_alignment - 1)) == 0;
       Redirection* redirection = Redirection::FromSwiInstruction(instr);
       int32_t arg0 = get_register(r0);
       int32_t arg1 = get_register(r1);
       int32_t arg2 = get_register(r2);
       int32_t arg3 = get_register(r3);
       // This is dodgy but it works because the C entry stubs are never moved.
       // See comment in codegen-arm.cc and bug 1242173.
       int32_t saved_lr = get_register(lr);
       if (redirection->fp_return()) {
         intptr_t external =
             reinterpret_cast<intptr_t>(redirection->external_function());
         SimulatorRuntimeFPCall target =
             reinterpret_cast<SimulatorRuntimeFPCall>(external);
-        if (::v8::internal::FLAG_trace_sim) {
+        if (::v8::internal::FLAG_trace_sim || !stack_aligned) {
           double x, y;
           GetFpArgs(&x, &y);
-          PrintF("Call to host function at %p with args %f, %f\n",
+          PrintF("Call to host function at %p with args %f, %f",
                  FUNCTION_ADDR(target), x, y);
+          if (!stack_aligned) {
+            PrintF(" with unaligned stack %08x\n", get_register(sp));
+          }
+          PrintF("\n");
         }
+        CHECK(stack_aligned);
         double result = target(arg0, arg1, arg2, arg3);
         SetFpResult(result);
       } else {
         intptr_t external =
             reinterpret_cast<int32_t>(redirection->external_function());
         SimulatorRuntimeCall target =
             reinterpret_cast<SimulatorRuntimeCall>(external);
-        if (::v8::internal::FLAG_trace_sim) {
+        if (::v8::internal::FLAG_trace_sim || !stack_aligned) {
           PrintF(
-              "Call to host function at %p with args %08x, %08x, %08x, %08x\n",
+              "Call to host function at %p with args %08x, %08x, %08x, %08x",
               FUNCTION_ADDR(target),
               arg0,
               arg1,
               arg2,
               arg3);
+          if (!stack_aligned) {
+            PrintF(" with unaligned stack %08x\n", get_register(sp));
+          }
+          PrintF("\n");
         }
+        CHECK(stack_aligned);
         int64_t result = target(arg0, arg1, arg2, arg3);
         int32_t lo_res = static_cast<int32_t>(result);
         int32_t hi_res = static_cast<int32_t>(result >> 32);
         if (::v8::internal::FLAG_trace_sim) {
           PrintF("Returned %08x\n", lo_res);
         }
         set_register(r0, lo_res);
         set_register(r1, hi_res);
       }
       set_register(lr, saved_lr);
@@ skipping 1221 matching lines @@
   uintptr_t* stack_slot = reinterpret_cast<uintptr_t*>(current_sp);
   uintptr_t address = *stack_slot;
   set_register(sp, current_sp + sizeof(uintptr_t));
   return address;
 }
 
 
 } }  // namespace assembler::arm
 
 #endif  // !defined(__arm__)