VM: Refactor assembler test that rely on the constant pool.

runtime/vm/unit_test.h

Index: runtime/vm/unit_test.h
diff --git a/runtime/vm/unit_test.h b/runtime/vm/unit_test.h
index 01ba00926e5dbba4eb3a75a2e2a04ec5ed2c76e5..5a22372c96c0e8e3e9c3b57267cbbfd084de7227 100644
--- a/runtime/vm/unit_test.h
+++ b/runtime/vm/unit_test.h
@@ -321,6 +321,26 @@ class TestIsolateScope {
 };
 
 
+template<typename T> struct is_void {
+  static const bool value = false;
+};
+
+
+template<> struct is_void<void> {
+  static const bool value = true;
+};
+
+
+template<typename T> struct is_double {
+  static const bool value = false;
+};
+
+
+template<> struct is_double<double> {
+  static const bool value = true;
+};
+
+
 class AssemblerTest {
  public:
   AssemblerTest(const char* name, Assembler* assembler)
@@ -337,6 +357,64 @@ class AssemblerTest {
   const Code& code() const { return code_; }
 
   uword entry() const { return entry_; }
+#if defined(USING_SIMULATOR)

[zra, 2015/08/11 19:48:17]

Please add comments here about how to use Invoke() and the restrictions on the
argument/return types.

[Florian Schneider, 2015/08/12 07:30:53]

If you happen to write a test that requires a new return-type which needs
special handling, the compiler will complain.

The point of using templates is that you get a compile-time error when something
is not right. Therefore, I don't see the need for additional comments.

[zra, 2015/08/17 16:35:43]

Template errors from the compiler are hard to read. I'm not sure this is a good
trade-off.

+  template<typename ResultType> ResultType Invoke() {
+    const bool fp_return = is_double<ResultType>::value;
+    COMPILE_ASSERT(!fp_return);
+    const bool fp_args = false;
+    return static_cast<ResultType>(Simulator::Current()->Call(
+        bit_cast<intptr_t, uword>(entry()), 0, 0, 0, 0, fp_return, fp_args));
+  }
+  template<typename ResultType, typename Arg1Type>
+  ResultType Invoke(Arg1Type arg1) {
+    const bool fp_return = is_double<ResultType>::value;
+    COMPILE_ASSERT(!fp_return);
+    const bool fp_args = false;
+    COMPILE_ASSERT(!is_double<Arg1Type>::value);
+    return static_cast<ResultType>(Simulator::Current()->Call(
+        bit_cast<intptr_t, uword>(entry()),
+        reinterpret_cast<intptr_t>(arg1),
+        0, 0, 0, fp_return, fp_args));
+  }
+  template<typename ResultType,
+           typename Arg1Type,
+           typename Arg2Type,
+           typename Arg3Type>
+  ResultType Invoke(Arg1Type arg1, Arg2Type arg2, Arg3Type arg3) {
+    COMPILE_ASSERT(is_void<ResultType>::value);
+    const bool fp_return = false;
+    COMPILE_ASSERT(!is_double<Arg1Type>::value);
+    COMPILE_ASSERT(!is_double<Arg2Type>::value);
+    COMPILE_ASSERT(!is_double<Arg3Type>::value);
+    const bool fp_args = false;
+    return static_cast<ResultType>(Simulator::Current()->Call(
+        bit_cast<intptr_t, uword>(entry()),
+        reinterpret_cast<intptr_t>(arg1),
+        reinterpret_cast<intptr_t>(arg2),
+        reinterpret_cast<intptr_t>(arg3),
+        0, fp_return, fp_args));
+  }
+#else
+  template<typename ResultType> ResultType Invoke() {
+    typedef ResultType (*FunctionType) ();
+    return reinterpret_cast<FunctionType>(entry())();
+  }
+
+  template<typename ResultType, typename Arg1Type>
+  ResultType Invoke(Arg1Type arg1) {
+    typedef ResultType (*FunctionType) (Arg1Type);
+    return reinterpret_cast<FunctionType>(entry())(arg1);
+  }
+
+  template<typename ResultType,
+           typename Arg1Type,
+           typename Arg2Type,
+           typename Arg3Type>
+  ResultType Invoke(Arg1Type arg1, Arg2Type arg2, Arg3Type arg3) {
+    typedef ResultType (*FunctionType) (Arg1Type, Arg2Type, Arg3Type);
+    return reinterpret_cast<FunctionType>(entry())(arg1, arg2, arg3);
+  }
+#endif
 
   // Assemble test and set code_ and entry_.
   void Assemble();