Move utils.h and utils.cc from runtime/vm to runtime/platform

runtime/platform/globals.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef PLATFORM_GLOBALS_H_
 #define PLATFORM_GLOBALS_H_
 
 // __STDC_FORMAT_MACROS has to be defined to enable platform independent printf.
 #ifndef __STDC_FORMAT_MACROS
 #define __STDC_FORMAT_MACROS
@@ skipping 43 matching lines @@
 #if defined(__linux__) || defined(__FreeBSD__)
 #define TARGET_OS_LINUX 1
 #elif defined(__APPLE__)
 #define TARGET_OS_MACOS 1
 #elif defined(_WIN32)
 #define TARGET_OS_WINDOWS 1
 #else
 #error Automatic target os detection failed.
 #endif
 
+// Processor architecture detection.  For more info on what's defined, see:
+//   http://msdn.microsoft.com/en-us/library/b0084kay.aspx
+//   http://www.agner.org/optimize/calling_conventions.pdf
+//   or with gcc, run: "echo | gcc -E -dM -"
+#if defined(_M_X64) || defined(__x86_64__)
+#define HOST_ARCH_X64 1
+#define ARCH_IS_64_BIT 1
+#elif defined(_M_IX86) || defined(__i386__)
+#define HOST_ARCH_IA32 1
+#define ARCH_IS_32_BIT 1
+#elif defined(__ARMEL__)
+#define HOST_ARCH_ARM 1
+#define ARCH_IS_32_BIT 1
+#else
+#error Architecture was not detected as supported by Dart.
+#endif
+
+#if !defined(TARGET_ARCH_ARM)
+#if !defined(TARGET_ARCH_X64)
+#if !defined(TARGET_ARCH_IA32)
+// No target architecture specified pick the one matching the host architecture.
+#if defined(HOST_ARCH_ARM)
+#define TARGET_ARCH_ARM 1
+#elif defined(HOST_ARCH_X64)
+#define TARGET_ARCH_X64 1
+#elif defined(HOST_ARCH_IA32)
+#define TARGET_ARCH_IA32 1
+#else
+#error Automatic target architecture detection failed.
+#endif
+#endif
+#endif
+#endif
+
+// Verify that host and target architectures match, we cannot
+// have a 64 bit Dart VM generating 32 bit code or vice-versa.
+#if defined(TARGET_ARCH_X64)
+#if !defined(ARCH_IS_64_BIT)
+#error Mismatched Host/Target architectures.
+#endif
+#elif defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_ARM)
+#if !defined(ARCH_IS_32_BIT)
+#error Mismatched Host/Target architectures.
+#endif
+#endif
+
+
+// Printf format for intptr_t on Windows.
+#if !defined(PRIxPTR) && defined(TARGET_OS_WINDOWS)
+#if defined(ARCH_IS_32_BIT)
+#define PRIxPTR "x"
+#else
+#define PRIxPTR "llx"
+#endif  // defined(ARCH_IS_32_BIT)
+#endif  // !defined(PRIxPTR) && defined(TARGET_OS_WINDOWS)
+
+
+// Suffixes for 64-bit integer literals.
+#ifdef _MSC_VER
+#define DART_INT64_C(x) x##I64
+#define DART_UINT64_C(x) x##UI64
+#else
+#define DART_INT64_C(x) x##LL
+#define DART_UINT64_C(x) x##ULL
+#endif
+
+
+// The following macro works on both 32 and 64-bit platforms.
+// Usage: instead of writing 0x1234567890123456
+//      write DART_2PART_UINT64_C(0x12345678,90123456);
+#define DART_2PART_UINT64_C(a, b)                                              \
+                 (((static_cast<uint64_t>(a) << 32) + 0x##b##u))
+
+
+// Types for native machine words. Guaranteed to be able to hold pointers and
+// integers.
+typedef intptr_t word;
+typedef uintptr_t uword;
+
+// Byte sizes.
+const int kWordSize = sizeof(word);
+#ifdef ARCH_IS_32_BIT
+const int kWordSizeLog2 = 2;
+#else
+const int kWordSizeLog2 = 3;
+#endif
+
+// Bit sizes.
+const int kBitsPerByte = 8;
+const int kBitsPerByteLog2 = 3;
+const int kBitsPerWord = kWordSize * kBitsPerByte;
+
+// System-wide named constants.
+const int KB = 1024;
+const int MB = KB * KB;
+const int GB = KB * KB * KB;
+const intptr_t kIntptrOne = 1;
+const intptr_t kIntptrMin = (kIntptrOne << (kBitsPerWord - 1));
+const intptr_t kIntptrMax = ~kIntptrMin;
+
+// Time constants.
+const int kMillisecondsPerSecond = 1000;
+const int kMicrosecondsPerMillisecond = 1000;
+const int kMicrosecondsPerSecond = (kMicrosecondsPerMillisecond *
+                                    kMillisecondsPerSecond);
+const int kNanosecondsPerMicrosecond = 1000;
+const int kNanosecondsPerMillisecond = (kNanosecondsPerMicrosecond *
+                                        kMicrosecondsPerMillisecond);
+const int kNanosecondsPerSecond = (kNanosecondsPerMicrosecond *
+                                   kMicrosecondsPerSecond);
 
 // A macro to disallow the copy constructor and operator= functions.
 // This should be used in the private: declarations for a class.
 #define DISALLOW_COPY_AND_ASSIGN(TypeName)                                     \
 private:                                                                       \
   TypeName(const TypeName&);                                                   \
   void operator=(const TypeName&)
 
 
 // A macro to disallow all the implicit constructors, namely the default
@@ skipping 15 matching lines @@
 private:                                                                       \
   void* operator new(size_t size);
 
 
 // The USE(x) template is used to silence C++ compiler warnings issued
 // for unused variables.
 template <typename T>
 static inline void USE(T) { }
 
 
+// Use implicit_cast as a safe version of static_cast or const_cast
+// for upcasting in the type hierarchy (i.e. casting a pointer to Foo
+// to a pointer to SuperclassOfFoo or casting a pointer to Foo to
+// a const pointer to Foo).
+// When you use implicit_cast, the compiler checks that the cast is safe.
+// Such explicit implicit_casts are necessary in surprisingly many
+// situations where C++ demands an exact type match instead of an
+// argument type convertable to a target type.
+//
+// The From type can be inferred, so the preferred syntax for using
+// implicit_cast is the same as for static_cast etc.:
+//
+//   implicit_cast<ToType>(expr)
+//
+// implicit_cast would have been part of the C++ standard library,
+// but the proposal was submitted too late.  It will probably make
+// its way into the language in the future.
+template<typename To, typename From>
+inline To implicit_cast(From const &f) {
+  return f;
+}
+
+
+// Use like this: down_cast<T*>(foo);
+template<typename To, typename From>  // use like this: down_cast<T*>(foo);
+inline To down_cast(From* f) {  // so we only accept pointers
+  // Ensures that To is a sub-type of From *.  This test is here only
+  // for compile-time type checking, and has no overhead in an
+  // optimized build at run-time, as it will be optimized away completely.
+  if (false) {
+    implicit_cast<From, To>(0);
+  }
+  return static_cast<To>(f);
+}
+
+
+// The type-based aliasing rule allows the compiler to assume that
+// pointers of different types (for some definition of different)
+// never alias each other. Thus the following code does not work:
+//
+// float f = foo();
+// int fbits = *(int*)(&f);
+//
+// The compiler 'knows' that the int pointer can't refer to f since
+// the types don't match, so the compiler may cache f in a register,
+// leaving random data in fbits.  Using C++ style casts makes no
+// difference, however a pointer to char data is assumed to alias any
+// other pointer. This is the 'memcpy exception'.
+//
+// The bit_cast function uses the memcpy exception to move the bits
+// from a variable of one type to a variable of another type. Of
+// course the end result is likely to be implementation dependent.
+// Most compilers (gcc-4.2 and MSVC 2005) will completely optimize
+// bit_cast away.
+//
+// There is an additional use for bit_cast. Recent gccs will warn when
+// they see casts that may result in breakage due to the type-based
+// aliasing rule. If you have checked that there is no breakage you
+// can use bit_cast to cast one pointer type to another. This confuses
+// gcc enough that it can no longer see that you have cast one pointer
+// type to another thus avoiding the warning.
+template <class D, class S>
+inline D bit_cast(const S& source) {
+  // Compile time assertion: sizeof(D) == sizeof(S). A compile error
+  // here means your D and S have different sizes.
+  typedef char VerifySizesAreEqual[sizeof(D) == sizeof(S) ? 1 : -1];
+
+  D destination;
+  // This use of memcpy is safe: source and destination cannot overlap.
+  memcpy(&destination, &source, sizeof(destination));
+  return destination;
+}
+
+
+// Similar to bit_cast, but allows copying from types of unrelated
+// sizes. This method was introduced to enable the strict aliasing
+// optimizations of GCC 4.4. Basically, GCC mindlessly relies on
+// obscure details in the C++ standard that make reinterpret_cast
+// virtually useless.
+template<class D, class S>
+inline D bit_copy(const S& source) {
+  D destination;
+  // This use of memcpy is safe: source and destination cannot overlap.
+  memcpy(&destination,
+         reinterpret_cast<const void*>(&source),
+         sizeof(destination));
+  return destination;
+}
+
+
+// A macro to ensure that memcpy cannot be called. memcpy does not handle
+// overlapping memory regions. Even though this is well documented it seems
+// to be used in error quite often. To avoid problems we disallow the direct
+// use of memcpy here.
+//
+// On Windows the basic libraries use memcpy and therefore compilation will
+// fail if memcpy is overwritten even if user code does not use memcpy.
+#if defined(memcpy)
+#undef memcpy
+#endif
+#if !defined(TARGET_OS_WINDOWS)
+#define memcpy "Please use memmove instead of memcpy."
+#endif
+
+
 // On Windows the reentrent version of strtok is called
 // strtok_s. Unify on the posix name strtok_r.
 #if defined(TARGET_OS_WINDOWS)
 #define snprintf _snprintf
 #define strtok_r strtok_s
 #endif
 
 #if !defined(TARGET_OS_WINDOWS) && !defined(TEMP_FAILURE_RETRY)
 // TEMP_FAILURE_RETRY is defined in unistd.h on some platforms. The
 // definition below is copied from Linux and adapted to avoid lint
 // errors (type long int changed to int64_t and do/while split on
 // separate lines with body in {}s).
 # define TEMP_FAILURE_RETRY(expression)                                        \
     ({ int64_t __result;                                                       \
        do {                                                                    \
          __result = (int64_t) (expression);                                    \
        } while (__result == -1L && errno == EINTR);                            \
        __result; })
 #endif
 
 #endif  // PLATFORM_GLOBALS_H_