[Interpreter] Textual representation for runtime function IDs.

test/cctest/interpreter/bytecode-expectations-printer.cc

Index: test/cctest/interpreter/bytecode-expectations-printer.cc
diff --git a/test/cctest/interpreter/bytecode-expectations-printer.cc b/test/cctest/interpreter/bytecode-expectations-printer.cc
index d5e0456511528a13bf0f68c0d81c937fa06e44c8..244c1478778c342d28eb01517349713505e87cb5 100644
--- a/test/cctest/interpreter/bytecode-expectations-printer.cc
+++ b/test/cctest/interpreter/bytecode-expectations-printer.cc
@@ -13,6 +13,7 @@
 #include "src/base/logging.h"
 #include "src/base/smart-pointers.h"
 #include "src/compiler.h"
+#include "src/runtime/runtime.h"
 
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-generator.h"
@@ -136,7 +137,13 @@ void BytecodeExpectationsPrinter::PrintBytecodeOperand(
   } else {
     stream << 'U' << size_tag << '(';
 
-    if (Bytecodes::IsImmediateOperandType(op_type)) {
+    if (op_index == 0 && Bytecodes::IsCallRuntime(bytecode)) {
+      stream << "Runtime::"
+             << i::Runtime::FunctionForId(

[oth, 2016/02/23 17:37:15]

Nit - this is a bit dense with braces and brackets. It might be more readable to
put the index operand value into a variable before outputting to the stream or
have an inline helper function that converts op_index into an
i::Runtime::FunctionId.

[Stefano Sanfilippo, 2016/02/23 17:43:50]

Done.

+                    static_cast<i::Runtime::FunctionId>(
+                        bytecode_iter.GetIndexOperand(op_index)))
+                    ->name;
+    } else if (Bytecodes::IsImmediateOperandType(op_type)) {
       // We need a cast, otherwise the result is printed as char.
       stream << static_cast<int>(bytecode_iter.GetImmediateOperand(op_index));
     } else if (Bytecodes::IsRegisterCountOperandType(op_type)) {