Fix stack alignment corruption for MinGW32 build

test/cctest/test-platform.cc

Index: test/cctest/test-platform.cc
diff --git a/test/cctest/test-platform.cc b/test/cctest/test-platform.cc
index 6c20b853c5e7408b1877ee74617c01c3fc32ed5f..7c8d4a450379b54f4ec372731608ff25d5f48197 100644
--- a/test/cctest/test-platform.cc
+++ b/test/cctest/test-platform.cc
@@ -35,3 +35,65 @@ using namespace ::v8::internal;
 TEST(NumberOfCores) {
   CHECK_GT(OS::NumberOfCores(), 0);
 }
+
+
+#ifdef __GNUC__
+#define ASM __asm__ __volatile__
+
+#if defined(_M_X64) || defined(__x86_64__)
+#define GET_STACK_POINTER() \
+  static int sp_addr = 0; \
+  do { \
+    ASM("mov %%rsp, %0" : "=g" (sp_addr)); \
+  } while (0)
+#elif defined(_M_IX86) || defined(__i386__)
+#define GET_STACK_POINTER() \
+  static int sp_addr = 0; \
+  do { \
+    ASM("mov %%esp, %0" : "=g" (sp_addr)); \
+  } while (0)
+#elif defined(__ARMEL__)
+#define GET_STACK_POINTER() \
+  static int sp_addr = 0; \
+  do { \
+    ASM("str %%sp, %0" : "=g" (sp_addr)); \
+  } while (0)
+#elif defined(__MIPSEL__)
+#define GET_STACK_POINTER() \
+  static int sp_addr = 0; \
+  do { \
+    ASM("sw $sp, %0" : "=g" (sp_addr)); \
+  } while (0)
+#else
+#error Host architecture was not detected as supported by v8
+#endif
+
+void GetStackPointer(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  GET_STACK_POINTER();
+  args.GetReturnValue().Set(v8_num(sp_addr));
+}
+
+TEST(StackAlignment) {
+  v8::Isolate* isolate = v8::Isolate::GetCurrent();
+  v8::HandleScope handle_scope(isolate);
+  v8::Handle<v8::ObjectTemplate> global_template = v8::ObjectTemplate::New();
+  global_template->Set(v8_str("get_stack_pointer"),
+                       v8::FunctionTemplate::New(GetStackPointer));
+
+  LocalContext env(NULL, global_template);
+  CompileRun(
+      "function foo() {"
+      "  return get_stack_pointer();"
+      "}");
+
+  v8::Local<v8::Object> global_object = env->Global();
+  v8::Local<v8::Function> foo =
+      v8::Local<v8::Function>::Cast(global_object->Get(v8_str("foo")));
+
+  v8::Local<v8::Value> result = foo->Call(global_object, 0, NULL);
+  CHECK_EQ(0, result->Int32Value() % OS::ActivationFrameAlignment());
+}
+
+#undef GET_STACK_POINTERS
+#undef ASM
+#endif  // __GNUC__