Reland 21482 - "Merge v8globals.h and globals.h"

src/v8globals.h

-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_V8GLOBALS_H_
-#define V8_V8GLOBALS_H_
-
-#include "globals.h"
-#include "checks.h"
-
-namespace v8 {
-namespace internal {
-
-// This file contains constants and global declarations related to the
-// V8 system.
-
-// Mask for the sign bit in a smi.
-const intptr_t kSmiSignMask = kIntptrSignBit;
-
-const int kObjectAlignmentBits = kPointerSizeLog2;
-const intptr_t kObjectAlignment = 1 << kObjectAlignmentBits;
-const intptr_t kObjectAlignmentMask = kObjectAlignment - 1;
-
-// Desired alignment for pointers.
-const intptr_t kPointerAlignment = (1 << kPointerSizeLog2);
-const intptr_t kPointerAlignmentMask = kPointerAlignment - 1;
-
-// Desired alignment for double values.
-const intptr_t kDoubleAlignment = 8;
-const intptr_t kDoubleAlignmentMask = kDoubleAlignment - 1;
-
-// Desired alignment for generated code is 32 bytes (to improve cache line
-// utilization).
-const int kCodeAlignmentBits = 5;
-const intptr_t kCodeAlignment = 1 << kCodeAlignmentBits;
-const intptr_t kCodeAlignmentMask = kCodeAlignment - 1;
-
-// Tag information for Failure.
-// TODO(yangguo): remove this from space owner calculation.
-const int kFailureTag = 3;
-const int kFailureTagSize = 2;
-const intptr_t kFailureTagMask = (1 << kFailureTagSize) - 1;
-
-
-// Zap-value: The value used for zapping dead objects.
-// Should be a recognizable hex value tagged as a failure.
-#ifdef V8_HOST_ARCH_64_BIT
-const Address kZapValue =
-    reinterpret_cast<Address>(V8_UINT64_C(0xdeadbeedbeadbeef));
-const Address kHandleZapValue =
-    reinterpret_cast<Address>(V8_UINT64_C(0x1baddead0baddeaf));
-const Address kGlobalHandleZapValue =
-    reinterpret_cast<Address>(V8_UINT64_C(0x1baffed00baffedf));
-const Address kFromSpaceZapValue =
-    reinterpret_cast<Address>(V8_UINT64_C(0x1beefdad0beefdaf));
-const uint64_t kDebugZapValue = V8_UINT64_C(0xbadbaddbbadbaddb);
-const uint64_t kSlotsZapValue = V8_UINT64_C(0xbeefdeadbeefdeef);
-const uint64_t kFreeListZapValue = 0xfeed1eaffeed1eaf;
-#else
-const Address kZapValue = reinterpret_cast<Address>(0xdeadbeef);
-const Address kHandleZapValue = reinterpret_cast<Address>(0xbaddeaf);
-const Address kGlobalHandleZapValue = reinterpret_cast<Address>(0xbaffedf);
-const Address kFromSpaceZapValue = reinterpret_cast<Address>(0xbeefdaf);
-const uint32_t kSlotsZapValue = 0xbeefdeef;
-const uint32_t kDebugZapValue = 0xbadbaddb;
-const uint32_t kFreeListZapValue = 0xfeed1eaf;
-#endif
-
-const int kCodeZapValue = 0xbadc0de;
-
-// Number of bits to represent the page size for paged spaces. The value of 20
-// gives 1Mb bytes per page.
-const int kPageSizeBits = 20;
-
-// On Intel architecture, cache line size is 64 bytes.
-// On ARM it may be less (32 bytes), but as far this constant is
-// used for aligning data, it doesn't hurt to align on a greater value.
-#define PROCESSOR_CACHE_LINE_SIZE 64
-
-// Constants relevant to double precision floating point numbers.
-// If looking only at the top 32 bits, the QNaN mask is bits 19 to 30.
-const uint32_t kQuietNaNHighBitsMask = 0xfff << (51 - 32);
-
-
-// -----------------------------------------------------------------------------
-// Forward declarations for frequently used classes
-
-class AccessorInfo;
-class Allocation;
-class Arguments;
-class Assembler;
-class Code;
-class CodeGenerator;
-class CodeStub;
-class Context;
-class Debug;
-class Debugger;
-class DebugInfo;
-class Descriptor;
-class DescriptorArray;
-class TransitionArray;
-class ExternalReference;
-class FixedArray;
-class FunctionTemplateInfo;
-class MemoryChunk;
-class SeededNumberDictionary;
-class UnseededNumberDictionary;
-class NameDictionary;
-template <typename T> class MaybeHandle;
-template <typename T> class Handle;
-class Heap;
-class HeapObject;
-class IC;
-class InterceptorInfo;
-class Isolate;
-class JSReceiver;
-class JSArray;
-class JSFunction;
-class JSObject;
-class LargeObjectSpace;
-class LookupResult;
-class MacroAssembler;
-class Map;
-class MapSpace;
-class MarkCompactCollector;
-class NewSpace;
-class Object;
-class OldSpace;
-class Foreign;
-class Scope;
-class ScopeInfo;
-class Script;
-class Smi;
-template <typename Config, class Allocator = FreeStoreAllocationPolicy>
-    class SplayTree;
-class String;
-class Name;
-class Struct;
-class Variable;
-class RelocInfo;
-class Deserializer;
-class MessageLocation;
-class VirtualMemory;
-class Mutex;
-class RecursiveMutex;
-
-typedef bool (*WeakSlotCallback)(Object** pointer);
-
-typedef bool (*WeakSlotCallbackWithHeap)(Heap* heap, Object** pointer);
-
-// -----------------------------------------------------------------------------
-// Miscellaneous
-
-// NOTE: SpaceIterator depends on AllocationSpace enumeration values being
-// consecutive.
-enum AllocationSpace {
-  NEW_SPACE,            // Semispaces collected with copying collector.
-  OLD_POINTER_SPACE,    // May contain pointers to new space.
-  OLD_DATA_SPACE,       // Must not have pointers to new space.
-  CODE_SPACE,           // No pointers to new space, marked executable.
-  MAP_SPACE,            // Only and all map objects.
-  CELL_SPACE,           // Only and all cell objects.
-  PROPERTY_CELL_SPACE,  // Only and all global property cell objects.
-  LO_SPACE,             // Promoted large objects.
-  INVALID_SPACE,        // Only used in AllocationResult to signal success.
-
-  FIRST_SPACE = NEW_SPACE,
-  LAST_SPACE = LO_SPACE,
-  FIRST_PAGED_SPACE = OLD_POINTER_SPACE,
-  LAST_PAGED_SPACE = PROPERTY_CELL_SPACE
-};
-const int kSpaceTagSize = 3;
-const int kSpaceTagMask = (1 << kSpaceTagSize) - 1;
-
-
-// A flag that indicates whether objects should be pretenured when
-// allocated (allocated directly into the old generation) or not
-// (allocated in the young generation if the object size and type
-// allows).
-enum PretenureFlag { NOT_TENURED, TENURED };
-
-enum MinimumCapacity {
-  USE_DEFAULT_MINIMUM_CAPACITY,
-  USE_CUSTOM_MINIMUM_CAPACITY
-};
-
-enum GarbageCollector { SCAVENGER, MARK_COMPACTOR };
-
-enum Executability { NOT_EXECUTABLE, EXECUTABLE };
-
-enum VisitMode {
-  VISIT_ALL,
-  VISIT_ALL_IN_SCAVENGE,
-  VISIT_ALL_IN_SWEEP_NEWSPACE,
-  VISIT_ONLY_STRONG
-};
-
-// Flag indicating whether code is built into the VM (one of the natives files).
-enum NativesFlag { NOT_NATIVES_CODE, NATIVES_CODE };
-
-
-// A CodeDesc describes a buffer holding instructions and relocation
-// information. The instructions start at the beginning of the buffer
-// and grow forward, the relocation information starts at the end of
-// the buffer and grows backward.
-//
-//  |<--------------- buffer_size ---------------->|
-//  |<-- instr_size -->|        |<-- reloc_size -->|
-//  +==================+========+==================+
-//  |   instructions   |  free  |    reloc info    |
-//  +==================+========+==================+
-//  ^
-//  |
-//  buffer
-
-struct CodeDesc {
-  byte* buffer;
-  int buffer_size;
-  int instr_size;
-  int reloc_size;
-  Assembler* origin;
-};
-
-
-// Callback function used for iterating objects in heap spaces,
-// for example, scanning heap objects.
-typedef int (*HeapObjectCallback)(HeapObject* obj);
-
-
-// Callback function used for checking constraints when copying/relocating
-// objects. Returns true if an object can be copied/relocated from its
-// old_addr to a new_addr.
-typedef bool (*ConstraintCallback)(Address new_addr, Address old_addr);
-
-
-// Callback function on inline caches, used for iterating over inline caches
-// in compiled code.
-typedef void (*InlineCacheCallback)(Code* code, Address ic);
-
-
-// State for inline cache call sites. Aliased as IC::State.
-enum InlineCacheState {
-  // Has never been executed.
-  UNINITIALIZED,
-  // Has been executed but monomorhic state has been delayed.
-  PREMONOMORPHIC,
-  // Has been executed and only one receiver type has been seen.
-  MONOMORPHIC,
-  // Like MONOMORPHIC but check failed due to prototype.
-  MONOMORPHIC_PROTOTYPE_FAILURE,
-  // Multiple receiver types have been seen.
-  POLYMORPHIC,
-  // Many receiver types have been seen.
-  MEGAMORPHIC,
-  // A generic handler is installed and no extra typefeedback is recorded.
-  GENERIC,
-  // Special state for debug break or step in prepare stubs.
-  DEBUG_STUB
-};
-
-
-enum CallFunctionFlags {
-  NO_CALL_FUNCTION_FLAGS,
-  CALL_AS_METHOD,
-  // Always wrap the receiver and call to the JSFunction. Only use this flag
-  // both the receiver type and the target method are statically known.
-  WRAP_AND_CALL
-};
-
-
-enum CallConstructorFlags {
-  NO_CALL_CONSTRUCTOR_FLAGS,
-  // The call target is cached in the instruction stream.
-  RECORD_CONSTRUCTOR_TARGET
-};
-
-
-enum InlineCacheHolderFlag {
-  OWN_MAP,  // For fast properties objects.
-  PROTOTYPE_MAP  // For slow properties objects (except GlobalObjects).
-};
-
-
-// The Store Buffer (GC).
-typedef enum {
-  kStoreBufferFullEvent,
-  kStoreBufferStartScanningPagesEvent,
-  kStoreBufferScanningPageEvent
-} StoreBufferEvent;
-
-
-typedef void (*StoreBufferCallback)(Heap* heap,
-                                    MemoryChunk* page,
-                                    StoreBufferEvent event);
-
-
-// Union used for fast testing of specific double values.
-union DoubleRepresentation {
-  double  value;
-  int64_t bits;
-  DoubleRepresentation(double x) { value = x; }
-  bool operator==(const DoubleRepresentation& other) const {
-    return bits == other.bits;
-  }
-};
-
-
-// Union used for customized checking of the IEEE double types
-// inlined within v8 runtime, rather than going to the underlying
-// platform headers and libraries
-union IeeeDoubleLittleEndianArchType {
-  double d;
-  struct {
-    unsigned int man_low  :32;
-    unsigned int man_high :20;
-    unsigned int exp      :11;
-    unsigned int sign     :1;
-  } bits;
-};
-
-
-union IeeeDoubleBigEndianArchType {
-  double d;
-  struct {
-    unsigned int sign     :1;
-    unsigned int exp      :11;
-    unsigned int man_high :20;
-    unsigned int man_low  :32;
-  } bits;
-};
-
-
-// AccessorCallback
-struct AccessorDescriptor {
-  Object* (*getter)(Isolate* isolate, Object* object, void* data);
-  Object* (*setter)(
-      Isolate* isolate, JSObject* object, Object* value, void* data);
-  void* data;
-};
-
-
-// Logging and profiling.  A StateTag represents a possible state of
-// the VM. The logger maintains a stack of these. Creating a VMState
-// object enters a state by pushing on the stack, and destroying a
-// VMState object leaves a state by popping the current state from the
-// stack.
-
-enum StateTag {
-  JS,
-  GC,
-  COMPILER,
-  OTHER,
-  EXTERNAL,
-  IDLE
-};
-
-
-// -----------------------------------------------------------------------------
-// Macros
-
-// Testers for test.
-
-#define HAS_SMI_TAG(value) \
-  ((reinterpret_cast<intptr_t>(value) & kSmiTagMask) == kSmiTag)
-
-#define HAS_FAILURE_TAG(value) \
-  ((reinterpret_cast<intptr_t>(value) & kFailureTagMask) == kFailureTag)
-
-// OBJECT_POINTER_ALIGN returns the value aligned as a HeapObject pointer
-#define OBJECT_POINTER_ALIGN(value)                             \
-  (((value) + kObjectAlignmentMask) & ~kObjectAlignmentMask)
-
-// POINTER_SIZE_ALIGN returns the value aligned as a pointer.
-#define POINTER_SIZE_ALIGN(value)                               \
-  (((value) + kPointerAlignmentMask) & ~kPointerAlignmentMask)
-
-// CODE_POINTER_ALIGN returns the value aligned as a generated code segment.
-#define CODE_POINTER_ALIGN(value)                               \
-  (((value) + kCodeAlignmentMask) & ~kCodeAlignmentMask)
-
-// Support for tracking C++ memory allocation.  Insert TRACK_MEMORY("Fisk")
-// inside a C++ class and new and delete will be overloaded so logging is
-// performed.
-// This file (globals.h) is included before log.h, so we use direct calls to
-// the Logger rather than the LOG macro.
-#ifdef DEBUG
-#define TRACK_MEMORY(name) \
-  void* operator new(size_t size) { \
-    void* result = ::operator new(size); \
-    Logger::NewEventStatic(name, result, size); \
-    return result; \
-  } \
-  void operator delete(void* object) { \
-    Logger::DeleteEventStatic(name, object); \
-    ::operator delete(object); \
-  }
-#else
-#define TRACK_MEMORY(name)
-#endif
-
-
-// CPU feature flags.
-enum CpuFeature {
-    // x86
-    SSE4_1,
-    SSE3,
-    SAHF,
-    // ARM
-    VFP3,
-    ARMv7,
-    SUDIV,
-    UNALIGNED_ACCESSES,
-    MOVW_MOVT_IMMEDIATE_LOADS,
-    VFP32DREGS,
-    NEON,
-    // MIPS
-    FPU,
-    // ARM64
-    ALWAYS_ALIGN_CSP,
-    NUMBER_OF_CPU_FEATURES
-};
-
-
-// Used to specify if a macro instruction must perform a smi check on tagged
-// values.
-enum SmiCheckType {
-  DONT_DO_SMI_CHECK,
-  DO_SMI_CHECK
-};
-
-
-enum ScopeType {
-  EVAL_SCOPE,      // The top-level scope for an eval source.
-  FUNCTION_SCOPE,  // The top-level scope for a function.
-  MODULE_SCOPE,    // The scope introduced by a module literal
-  GLOBAL_SCOPE,    // The top-level scope for a program or a top-level eval.
-  CATCH_SCOPE,     // The scope introduced by catch.
-  BLOCK_SCOPE,     // The scope introduced by a new block.
-  WITH_SCOPE       // The scope introduced by with.
-};
-
-
-const uint32_t kHoleNanUpper32 = 0x7FFFFFFF;
-const uint32_t kHoleNanLower32 = 0xFFFFFFFF;
-const uint32_t kNaNOrInfinityLowerBoundUpper32 = 0x7FF00000;
-
-const uint64_t kHoleNanInt64 =
-    (static_cast<uint64_t>(kHoleNanUpper32) << 32) | kHoleNanLower32;
-const uint64_t kLastNonNaNInt64 =
-    (static_cast<uint64_t>(kNaNOrInfinityLowerBoundUpper32) << 32);
-
-
-// The order of this enum has to be kept in sync with the predicates below.
-enum VariableMode {
-  // User declared variables:
-  VAR,             // declared via 'var', and 'function' declarations
-
-  CONST_LEGACY,    // declared via legacy 'const' declarations
-
-  LET,             // declared via 'let' declarations (first lexical)
-
-  CONST,           // declared via 'const' declarations
-
-  MODULE,          // declared via 'module' declaration (last lexical)
-
-  // Variables introduced by the compiler:
-  INTERNAL,        // like VAR, but not user-visible (may or may not
-                   // be in a context)
-
-  TEMPORARY,       // temporary variables (not user-visible), stack-allocated
-                   // unless the scope as a whole has forced context allocation
-
-  DYNAMIC,         // always require dynamic lookup (we don't know
-                   // the declaration)
-
-  DYNAMIC_GLOBAL,  // requires dynamic lookup, but we know that the
-                   // variable is global unless it has been shadowed
-                   // by an eval-introduced variable
-
-  DYNAMIC_LOCAL    // requires dynamic lookup, but we know that the
-                   // variable is local and where it is unless it
-                   // has been shadowed by an eval-introduced
-                   // variable
-};
-
-
-inline bool IsDynamicVariableMode(VariableMode mode) {
-  return mode >= DYNAMIC && mode <= DYNAMIC_LOCAL;
-}
-
-
-inline bool IsDeclaredVariableMode(VariableMode mode) {
-  return mode >= VAR && mode <= MODULE;
-}
-
-
-inline bool IsLexicalVariableMode(VariableMode mode) {
-  return mode >= LET && mode <= MODULE;
-}
-
-
-inline bool IsImmutableVariableMode(VariableMode mode) {
-  return (mode >= CONST && mode <= MODULE) || mode == CONST_LEGACY;
-}
-
-
-// ES6 Draft Rev3 10.2 specifies declarative environment records with mutable
-// and immutable bindings that can be in two states: initialized and
-// uninitialized. In ES5 only immutable bindings have these two states. When
-// accessing a binding, it needs to be checked for initialization. However in
-// the following cases the binding is initialized immediately after creation
-// so the initialization check can always be skipped:
-// 1. Var declared local variables.
-//      var foo;
-// 2. A local variable introduced by a function declaration.
-//      function foo() {}
-// 3. Parameters
-//      function x(foo) {}
-// 4. Catch bound variables.
-//      try {} catch (foo) {}
-// 6. Function variables of named function expressions.
-//      var x = function foo() {}
-// 7. Implicit binding of 'this'.
-// 8. Implicit binding of 'arguments' in functions.
-//
-// ES5 specified object environment records which are introduced by ES elements
-// such as Program and WithStatement that associate identifier bindings with the
-// properties of some object. In the specification only mutable bindings exist
-// (which may be non-writable) and have no distinct initialization step. However
-// V8 allows const declarations in global code with distinct creation and
-// initialization steps which are represented by non-writable properties in the
-// global object. As a result also these bindings need to be checked for
-// initialization.
-//
-// The following enum specifies a flag that indicates if the binding needs a
-// distinct initialization step (kNeedsInitialization) or if the binding is
-// immediately initialized upon creation (kCreatedInitialized).
-enum InitializationFlag {
-  kNeedsInitialization,
-  kCreatedInitialized
-};
-
-
-enum ClearExceptionFlag {
-  KEEP_EXCEPTION,
-  CLEAR_EXCEPTION
-};
-
-
-enum MinusZeroMode {
-  TREAT_MINUS_ZERO_AS_ZERO,
-  FAIL_ON_MINUS_ZERO
-};
-
-} }  // namespace v8::internal
-
-namespace i = v8::internal;
-
-#endif  // V8_V8GLOBALS_H_