runtime/utils.h - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #ifndef ART_RUNTIME_UTILS_H_
 #define ART_RUNTIME_UTILS_H_

 #include <pthread.h>
 #include <stdlib.h>

 #include <limits>
 #include <memory>
 #include <random>
 #include <string>
 #include <type_traits>
 #include <vector>

 #include "arch/instruction_set.h"
 #include "base/casts.h"
 #include "base/logging.h"
 #include "base/stringpiece.h"
 #include "globals.h"
 #include "primitive.h"

 namespace art {

 template <typename T>
 bool ParseUint(const char *in, T* out) {
   char* end;
   unsigned long long int result = strtoull(in, &end, 0);  // NOLINT(runtime/int)
   if (in == end || *end != '\0') {
     return false;
   }
   if (std::numeric_limits<T>::max() < result) {
     return false;
   }
   *out = static_cast<T>(result);
   return true;
 }

 template <typename T>
 bool ParseInt(const char* in, T* out) {
   char* end;
   long long int result = strtoll(in, &end, 0);  // NOLINT(runtime/int)
   if (in == end || *end != '\0') {
     return false;
   }
   if (result < std::numeric_limits<T>::min() || std::numeric_limits<T>::max() < result) {
     return false;
   }
   *out = static_cast<T>(result);
   return true;
 }

 static inline uint32_t PointerToLowMemUInt32(const void* p) {
   uintptr_t intp = reinterpret_cast<uintptr_t>(p);
   DCHECK_LE(intp, 0xFFFFFFFFU);
   return intp & 0xFFFFFFFFU;
 }

 std::string PrintableChar(uint16_t ch);

 // Returns an ASCII string corresponding to the given UTF-8 string.
 // Java escapes are used for non-ASCII characters.
 std::string PrintableString(const char* utf8);

 // Used to implement PrettyClass, PrettyField, PrettyMethod, and PrettyTypeOf,
 // one of which is probably more useful to you.
 // Returns a human-readable equivalent of 'descriptor'. So "I" would be "int",
 // "[[I" would be "int[][]", "[Ljava/lang/String;" would be
 // "java.lang.String[]", and so forth.
 void AppendPrettyDescriptor(const char* descriptor, std::string* result);
 std::string PrettyDescriptor(const char* descriptor);
 std::string PrettyDescriptor(Primitive::Type type);

 // Returns a human-readable version of the Java part of the access flags, e.g., "private static "
 // (note the trailing whitespace).
 std::string PrettyJavaAccessFlags(uint32_t access_flags);

 // Returns a human-readable size string such as "1MB".
 std::string PrettySize(int64_t size_in_bytes);

 // Performs JNI name mangling as described in section 11.3 "Linking Native Methods"
 // of the JNI spec.
 std::string MangleForJni(const std::string& s);

 std::string GetJniShortName(const std::string& class_name, const std::string& method_name);

 // Turn "java.lang.String" into "Ljava/lang/String;".
 std::string DotToDescriptor(const char* class_name);

 // Turn "Ljava/lang/String;" into "java.lang.String" using the conventions of
 // java.lang.Class.getName().
 std::string DescriptorToDot(const char* descriptor);

 // Turn "Ljava/lang/String;" into "java/lang/String" using the opposite conventions of
 // java.lang.Class.getName().
 std::string DescriptorToName(const char* descriptor);

 // Tests for whether 's' is a valid class name in the three common forms:
 bool IsValidBinaryClassName(const char* s);  // "java.lang.String"
 bool IsValidJniClassName(const char* s);     // "java/lang/String"
 bool IsValidDescriptor(const char* s);       // "Ljava/lang/String;"

 // Returns whether the given string is a valid field or method name,
 // additionally allowing names that begin with '<' and end with '>'.
 bool IsValidMemberName(const char* s);

 bool ReadFileToString(const std::string& file_name, std::string* result);
 bool PrintFileToLog(const std::string& file_name, LogSeverity level);

 // Splits a string using the given separator character into a vector of
 // strings. Empty strings will be omitted.
 void Split(const std::string& s, char separator, std::vector<std::string>* result);

 // Returns the calling thread's tid. (The C libraries don't expose this.)
 pid_t GetTid();

 // Returns the given thread's name.
 std::string GetThreadName(pid_t tid);

 // Reads data from "/proc/self/task/${tid}/stat".
 void GetTaskStats(pid_t tid, char* state, int* utime, int* stime, int* task_cpu);

 // Sets the name of the current thread. The name may be truncated to an
 // implementation-defined limit.
 void SetThreadName(const char* thread_name);

 // Find $ANDROID_ROOT, /system, or abort.
 std::string GetAndroidRoot();
 // Find $ANDROID_ROOT, /system, or return an empty string.
 std::string GetAndroidRootSafe(std::string* error_msg);

 // Find $ANDROID_DATA, /data, or abort.
 const char* GetAndroidData();
 // Find $ANDROID_DATA, /data, or return null.
 const char* GetAndroidDataSafe(std::string* error_msg);

 // Returns the default boot image location (ANDROID_ROOT/framework/boot.art).
 // Returns an empty string if ANDROID_ROOT is not set.
 std::string GetDefaultBootImageLocation(std::string* error_msg);

 // Returns the dalvik-cache location, with subdir appended. Returns the empty string if the cache
 // could not be found.
 std::string GetDalvikCache(const char* subdir);
 // Return true if we found the dalvik cache and stored it in the dalvik_cache argument.
 // have_android_data will be set to true if we have an ANDROID_DATA that exists,
 // dalvik_cache_exists will be true if there is a dalvik-cache directory that is present.
 // The flag is_global_cache tells whether this cache is /data/dalvik-cache.
 void GetDalvikCache(const char* subdir, bool create_if_absent, std::string* dalvik_cache,
                     bool* have_android_data, bool* dalvik_cache_exists, bool* is_global_cache);

 // Returns the absolute dalvik-cache path for a DexFile or OatFile. The path returned will be
 // rooted at cache_location.
 bool GetDalvikCacheFilename(const char* file_location, const char* cache_location,
                             std::string* filename, std::string* error_msg);

 // Returns the system location for an image
 std::string GetSystemImageFilename(const char* location, InstructionSet isa);

 // Returns the vdex filename for the given oat filename.
 std::string GetVdexFilename(const std::string& oat_filename);

 // Returns true if the file exists.
 bool FileExists(const std::string& filename);
 bool FileExistsAndNotEmpty(const std::string& filename);

 // Returns `filename` with the text after the last occurrence of '.' replaced with
 // `extension`. If `filename` does not contain a period, returns a string containing `filename`,
 // a period, and `new_extension`.
 // Example: ReplaceFileExtension("foo.bar", "abc") == "foo.abc"
 //          ReplaceFileExtension("foo", "abc") == "foo.abc"
 std::string ReplaceFileExtension(const std::string& filename, const std::string& new_extension);

 class VoidFunctor {
  public:
   template <typename A>
   inline void operator() (A a ATTRIBUTE_UNUSED) const {
   }

   template <typename A, typename B>
   inline void operator() (A a ATTRIBUTE_UNUSED, B b ATTRIBUTE_UNUSED) const {
   }

   template <typename A, typename B, typename C>
   inline void operator() (A a ATTRIBUTE_UNUSED, B b ATTRIBUTE_UNUSED, C c ATTRIBUTE_UNUSED) const {
   }
 };

 inline bool TestBitmap(size_t idx, const uint8_t* bitmap) {
   return ((bitmap[idx / kBitsPerByte] >> (idx % kBitsPerByte)) & 0x01) != 0;
 }

 static inline constexpr bool ValidPointerSize(size_t pointer_size) {
   return pointer_size == 4 || pointer_size == 8;
 }

 static inline const void* EntryPointToCodePointer(const void* entry_point) {
   uintptr_t code = reinterpret_cast<uintptr_t>(entry_point);
   // TODO: Make this Thumb2 specific. It is benign on other architectures as code is always at
   //       least 2 byte aligned.
   code &= ~0x1;
   return reinterpret_cast<const void*>(code);
 }

 using UsageFn = void (*)(const char*, ...);

 template <typename T>
 static void ParseIntOption(const StringPiece& option,
                             const std::string& option_name,
                             T* out,
                             UsageFn usage,
                             bool is_long_option = true) {
   std::string option_prefix = option_name + (is_long_option ? "=" : "");
   DCHECK(option.starts_with(option_prefix)) << option << " " << option_prefix;
   const char* value_string = option.substr(option_prefix.size()).data();
   int64_t parsed_integer_value = 0;
   if (!ParseInt(value_string, &parsed_integer_value)) {
     usage("Failed to parse %s '%s' as an integer", option_name.c_str(), value_string);
   }
   *out = dchecked_integral_cast<T>(parsed_integer_value);
 }

 template <typename T>
 static void ParseUintOption(const StringPiece& option,
                             const std::string& option_name,
                             T* out,
                             UsageFn usage,
                             bool is_long_option = true) {
   ParseIntOption(option, option_name, out, usage, is_long_option);
   if (*out < 0) {
     usage("%s passed a negative value %d", option_name.c_str(), *out);
     *out = 0;
   }
 }

 void ParseDouble(const std::string& option,
                  char after_char,
                  double min,
                  double max,
                  double* parsed_value,
                  UsageFn Usage);

 #if defined(__BIONIC__)
 struct Arc4RandomGenerator {
   typedef uint32_t result_type;
   static constexpr uint32_t min() { return std::numeric_limits<uint32_t>::min(); }
   static constexpr uint32_t max() { return std::numeric_limits<uint32_t>::max(); }
   uint32_t operator() () { return arc4random(); }
 };
 using RNG = Arc4RandomGenerator;
 #else
 using RNG = std::random_device;
 #endif

 template <typename T>
 static T GetRandomNumber(T min, T max) {
   CHECK_LT(min, max);
   std::uniform_int_distribution<T> dist(min, max);
   RNG rng;
   return dist(rng);
 }

 // Return the file size in bytes or -1 if the file does not exists.
 int64_t GetFileSizeBytes(const std::string& filename);

 // Sleep forever and never come back.
 NO_RETURN void SleepForever();

 inline void FlushInstructionCache(char* begin, char* end) {
   __builtin___clear_cache(begin, end);
 }

 inline void FlushDataCache(char* begin, char* end) {
   // Same as FlushInstructionCache for lack of other builtin. __builtin___clear_cache
   // flushes both caches.
   __builtin___clear_cache(begin, end);
 }

 template <typename T>
 constexpr PointerSize ConvertToPointerSize(T any) {
   if (any == 4 || any == 8) {
     return static_cast<PointerSize>(any);
   } else {
     LOG(FATAL);
     UNREACHABLE();
   }
 }

 // Returns a type cast pointer if object pointed to is within the provided bounds.
 // Otherwise returns nullptr.
 template <typename T>
 inline static T BoundsCheckedCast(const void* pointer,
                                   const void* lower,
                                   const void* upper) {
   const uint8_t* bound_begin = static_cast<const uint8_t*>(lower);
   const uint8_t* bound_end = static_cast<const uint8_t*>(upper);
   DCHECK(bound_begin <= bound_end);

   T result = reinterpret_cast<T>(pointer);
   const uint8_t* begin = static_cast<const uint8_t*>(pointer);
   const uint8_t* end = begin + sizeof(*result);
   if (begin < bound_begin || end > bound_end || begin > end) {
     return nullptr;
   }
   return result;
 }

 template <typename T, size_t size>
 constexpr size_t ArrayCount(const T (&)[size]) {
   return size;
 }

 // Return -1 if <, 0 if ==, 1 if >.
 template <typename T>
 inline static int32_t Compare(T lhs, T rhs) {
   return (lhs < rhs) ? -1 : ((lhs == rhs) ? 0 : 1);
 }

 // Return -1 if < 0, 0 if == 0, 1 if > 0.
 template <typename T>
 inline static int32_t Signum(T opnd) {
   return (opnd < 0) ? -1 : ((opnd == 0) ? 0 : 1);
 }

 // Madvise the largest page aligned region within begin and end.
 int MadviseLargestPageAlignedRegion(const uint8_t* begin, const uint8_t* end, int advice);

 }  // namespace art

 #endif  // ART_RUNTIME_UTILS_H_
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#ifndef ART_RUNTIME_UTILS_H_
	#define ART_RUNTIME_UTILS_H_

	#include <pthread.h>
	#include <stdlib.h>

	#include <limits>
	#include <memory>
	#include <random>
	#include <string>
	#include <type_traits>
	#include <vector>

	#include "arch/instruction_set.h"
	#include "base/casts.h"
	#include "base/logging.h"
	#include "base/stringpiece.h"
	#include "globals.h"
	#include "primitive.h"

	namespace art {

	template <typename T>
	bool ParseUint(const char in, T out) {
	char* end;
	unsigned long long int result = strtoull(in, &end, 0); // NOLINT(runtime/int)
	if (in == end \|\| *end != '\0') {
	return false;
	}
	if (std::numeric_limits<T>::max() < result) {
	return false;
	}
	*out = static_cast<T>(result);
	return true;
	}

	template <typename T>
	bool ParseInt(const char* in, T* out) {
	char* end;
	long long int result = strtoll(in, &end, 0); // NOLINT(runtime/int)
	if (in == end \|\| *end != '\0') {
	return false;
	}
	if (result < std::numeric_limits<T>::min() \|\| std::numeric_limits<T>::max() < result) {
	return false;
	}
	*out = static_cast<T>(result);
	return true;
	}

	static inline uint32_t PointerToLowMemUInt32(const void* p) {
	uintptr_t intp = reinterpret_cast<uintptr_t>(p);
	DCHECK_LE(intp, 0xFFFFFFFFU);
	return intp & 0xFFFFFFFFU;
	}

	std::string PrintableChar(uint16_t ch);

	// Returns an ASCII string corresponding to the given UTF-8 string.
	// Java escapes are used for non-ASCII characters.
	std::string PrintableString(const char* utf8);

	// Used to implement PrettyClass, PrettyField, PrettyMethod, and PrettyTypeOf,
	// one of which is probably more useful to you.
	// Returns a human-readable equivalent of 'descriptor'. So "I" would be "int",
	// "[[I" would be "int[][]", "[Ljava/lang/String;" would be
	// "java.lang.String[]", and so forth.
	void AppendPrettyDescriptor(const char* descriptor, std::string* result);
	std::string PrettyDescriptor(const char* descriptor);
	std::string PrettyDescriptor(Primitive::Type type);

	// Returns a human-readable version of the Java part of the access flags, e.g., "private static "
	// (note the trailing whitespace).
	std::string PrettyJavaAccessFlags(uint32_t access_flags);

	// Returns a human-readable size string such as "1MB".
	std::string PrettySize(int64_t size_in_bytes);

	// Performs JNI name mangling as described in section 11.3 "Linking Native Methods"
	// of the JNI spec.
	std::string MangleForJni(const std::string& s);

	std::string GetJniShortName(const std::string& class_name, const std::string& method_name);

	// Turn "java.lang.String" into "Ljava/lang/String;".
	std::string DotToDescriptor(const char* class_name);

	// Turn "Ljava/lang/String;" into "java.lang.String" using the conventions of
	// java.lang.Class.getName().
	std::string DescriptorToDot(const char* descriptor);

	// Turn "Ljava/lang/String;" into "java/lang/String" using the opposite conventions of
	// java.lang.Class.getName().
	std::string DescriptorToName(const char* descriptor);

	// Tests for whether 's' is a valid class name in the three common forms:
	bool IsValidBinaryClassName(const char* s); // "java.lang.String"
	bool IsValidJniClassName(const char* s); // "java/lang/String"
	bool IsValidDescriptor(const char* s); // "Ljava/lang/String;"

	// Returns whether the given string is a valid field or method name,
	// additionally allowing names that begin with '<' and end with '>'.
	bool IsValidMemberName(const char* s);

	bool ReadFileToString(const std::string& file_name, std::string* result);
	bool PrintFileToLog(const std::string& file_name, LogSeverity level);

	// Splits a string using the given separator character into a vector of
	// strings. Empty strings will be omitted.
	void Split(const std::string& s, char separator, std::vector<std::string>* result);

	// Returns the calling thread's tid. (The C libraries don't expose this.)
	pid_t GetTid();

	// Returns the given thread's name.
	std::string GetThreadName(pid_t tid);

	// Reads data from "/proc/self/task/${tid}/stat".
	void GetTaskStats(pid_t tid, char* state, int* utime, int* stime, int* task_cpu);

	// Sets the name of the current thread. The name may be truncated to an
	// implementation-defined limit.
	void SetThreadName(const char* thread_name);

	// Find $ANDROID_ROOT, /system, or abort.
	std::string GetAndroidRoot();
	// Find $ANDROID_ROOT, /system, or return an empty string.
	std::string GetAndroidRootSafe(std::string* error_msg);

	// Find $ANDROID_DATA, /data, or abort.
	const char* GetAndroidData();
	// Find $ANDROID_DATA, /data, or return null.
	const char* GetAndroidDataSafe(std::string* error_msg);

	// Returns the default boot image location (ANDROID_ROOT/framework/boot.art).
	// Returns an empty string if ANDROID_ROOT is not set.
	std::string GetDefaultBootImageLocation(std::string* error_msg);

	// Returns the dalvik-cache location, with subdir appended. Returns the empty string if the cache
	// could not be found.
	std::string GetDalvikCache(const char* subdir);
	// Return true if we found the dalvik cache and stored it in the dalvik_cache argument.
	// have_android_data will be set to true if we have an ANDROID_DATA that exists,
	// dalvik_cache_exists will be true if there is a dalvik-cache directory that is present.
	// The flag is_global_cache tells whether this cache is /data/dalvik-cache.
	void GetDalvikCache(const char* subdir, bool create_if_absent, std::string* dalvik_cache,
	bool* have_android_data, bool* dalvik_cache_exists, bool* is_global_cache);

	// Returns the absolute dalvik-cache path for a DexFile or OatFile. The path returned will be
	// rooted at cache_location.
	bool GetDalvikCacheFilename(const char* file_location, const char* cache_location,
	std::string* filename, std::string* error_msg);

	// Returns the system location for an image
	std::string GetSystemImageFilename(const char* location, InstructionSet isa);

	// Returns the vdex filename for the given oat filename.
	std::string GetVdexFilename(const std::string& oat_filename);

	// Returns true if the file exists.
	bool FileExists(const std::string& filename);
	bool FileExistsAndNotEmpty(const std::string& filename);

	// Returns `filename` with the text after the last occurrence of '.' replaced with
	// `extension`. If `filename` does not contain a period, returns a string containing `filename`,
	// a period, and `new_extension`.
	// Example: ReplaceFileExtension("foo.bar", "abc") == "foo.abc"
	// ReplaceFileExtension("foo", "abc") == "foo.abc"
	std::string ReplaceFileExtension(const std::string& filename, const std::string& new_extension);

	class VoidFunctor {
	public:
	template <typename A>
	inline void operator() (A a ATTRIBUTE_UNUSED) const {
	}

	template <typename A, typename B>
	inline void operator() (A a ATTRIBUTE_UNUSED, B b ATTRIBUTE_UNUSED) const {
	}

	template <typename A, typename B, typename C>
	inline void operator() (A a ATTRIBUTE_UNUSED, B b ATTRIBUTE_UNUSED, C c ATTRIBUTE_UNUSED) const {
	}
	};

	inline bool TestBitmap(size_t idx, const uint8_t* bitmap) {
	return ((bitmap[idx / kBitsPerByte] >> (idx % kBitsPerByte)) & 0x01) != 0;
	}

	static inline constexpr bool ValidPointerSize(size_t pointer_size) {
	return pointer_size == 4 \|\| pointer_size == 8;
	}

	static inline const void* EntryPointToCodePointer(const void* entry_point) {
	uintptr_t code = reinterpret_cast<uintptr_t>(entry_point);
	// TODO: Make this Thumb2 specific. It is benign on other architectures as code is always at
	// least 2 byte aligned.
	code &= ~0x1;
	return reinterpret_cast<const void*>(code);
	}

	using UsageFn = void ()(const char, ...);

	template <typename T>
	static void ParseIntOption(const StringPiece& option,
	const std::string& option_name,
	T* out,
	UsageFn usage,
	bool is_long_option = true) {
	std::string option_prefix = option_name + (is_long_option ? "=" : "");
	DCHECK(option.starts_with(option_prefix)) << option << " " << option_prefix;
	const char* value_string = option.substr(option_prefix.size()).data();
	int64_t parsed_integer_value = 0;
	if (!ParseInt(value_string, &parsed_integer_value)) {
	usage("Failed to parse %s '%s' as an integer", option_name.c_str(), value_string);
	}
	*out = dchecked_integral_cast<T>(parsed_integer_value);
	}

	template <typename T>
	static void ParseUintOption(const StringPiece& option,
	const std::string& option_name,
	T* out,
	UsageFn usage,
	bool is_long_option = true) {
	ParseIntOption(option, option_name, out, usage, is_long_option);
	if (*out < 0) {
	usage("%s passed a negative value %d", option_name.c_str(), *out);
	*out = 0;
	}
	}

	void ParseDouble(const std::string& option,
	char after_char,
	double min,
	double max,
	double* parsed_value,
	UsageFn Usage);

	#if defined(__BIONIC__)
	struct Arc4RandomGenerator {
	typedef uint32_t result_type;
	static constexpr uint32_t min() { return std::numeric_limits<uint32_t>::min(); }
	static constexpr uint32_t max() { return std::numeric_limits<uint32_t>::max(); }
	uint32_t operator() () { return arc4random(); }
	};
	using RNG = Arc4RandomGenerator;
	#else
	using RNG = std::random_device;
	#endif

	template <typename T>
	static T GetRandomNumber(T min, T max) {
	CHECK_LT(min, max);
	std::uniform_int_distribution<T> dist(min, max);
	RNG rng;
	return dist(rng);
	}

	// Return the file size in bytes or -1 if the file does not exists.
	int64_t GetFileSizeBytes(const std::string& filename);

	// Sleep forever and never come back.
	NO_RETURN void SleepForever();

	inline void FlushInstructionCache(char* begin, char* end) {
	__builtin___clear_cache(begin, end);
	}

	inline void FlushDataCache(char* begin, char* end) {
	// Same as FlushInstructionCache for lack of other builtin. __builtin___clear_cache
	// flushes both caches.
	__builtin___clear_cache(begin, end);
	}

	template <typename T>
	constexpr PointerSize ConvertToPointerSize(T any) {
	if (any == 4 \|\| any == 8) {
	return static_cast<PointerSize>(any);
	} else {
	LOG(FATAL);
	UNREACHABLE();
	}
	}

	// Returns a type cast pointer if object pointed to is within the provided bounds.
	// Otherwise returns nullptr.
	template <typename T>
	inline static T BoundsCheckedCast(const void* pointer,
	const void* lower,
	const void* upper) {
	const uint8_t* bound_begin = static_cast<const uint8_t*>(lower);
	const uint8_t* bound_end = static_cast<const uint8_t*>(upper);
	DCHECK(bound_begin <= bound_end);

	T result = reinterpret_cast<T>(pointer);
	const uint8_t* begin = static_cast<const uint8_t*>(pointer);
	const uint8_t* end = begin + sizeof(*result);
	if (begin < bound_begin \|\| end > bound_end \|\| begin > end) {
	return nullptr;
	}
	return result;
	}

	template <typename T, size_t size>
	constexpr size_t ArrayCount(const T (&)[size]) {
	return size;
	}

	// Return -1 if <, 0 if ==, 1 if >.
	template <typename T>
	inline static int32_t Compare(T lhs, T rhs) {
	return (lhs < rhs) ? -1 : ((lhs == rhs) ? 0 : 1);
	}

	// Return -1 if < 0, 0 if == 0, 1 if > 0.
	template <typename T>
	inline static int32_t Signum(T opnd) {
	return (opnd < 0) ? -1 : ((opnd == 0) ? 0 : 1);
	}

	// Madvise the largest page aligned region within begin and end.
	int MadviseLargestPageAlignedRegion(const uint8_t* begin, const uint8_t* end, int advice);

	} // namespace art

	#endif // ART_RUNTIME_UTILS_H_