Add QtV8 library to QtBase

This adds Aaron's copy of V8 to src/3rdparty/v8 (as a
git submodule), and builds it as a "normal" Qt library
(without any dependencies on Qt itself).

The library can be added to a project with

QT += v8-private

V8 API headers are available as private includes, e.g.

 #include <private/v8.h>

The API is private because we're exposing a third-party
API directly, and we don't want to (and cannot) make
source or binary compatibility guarantees for it.

Since we want the V8 public API headers to be private
headers in Qt, syncqt and sync.profile were extended to
understand a new configuration option, the
@allmoduleheadersprivate array, that tells syncqt whether
all the library headers should be treated as private even
though they don't follow the _p.h Qt convention.

The V8 project files, patches and autotests are copied
from the QtDeclarative repository. The next step after
this commit is to remove QtDeclarative's copy of V8 and
link with QtV8 instead.

Task-number: QTBUG-20963
Change-Id: Ib8820362cdbc8fa662a5e97db841656cf38d1b62
Reviewed-on: http://codereview.qt.nokia.com/3092
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

1 files changed, 343 insertions, 0 deletions

diff --git a/src/v8/0001-Add-hashing-and-comparison-methods-to-v8-String.patch b/src/v8/0001-Add-hashing-and-comparison-methods-to-v8-String.patch
new file mode 100644
index 0000000000..54a35fda9f
--- /dev/null
+++ b/src/v8/0001-Add-hashing-and-comparison-methods-to-v8-String.patch
@@ -0,0 +1,343 @@
+From e13ce09287a56c920d5ffdc5d4662d49f1838f16 Mon Sep 17 00:00:00 2001
+From: Aaron Kennedy <aaron.kennedy@nokia.com>
+Date: Mon, 23 May 2011 15:47:20 +1000
+Subject: [PATCH 01/13] Add hashing and comparison methods to v8::String
+
+This allows us to more rapidly search for a v8::String inside
+a hash of QStrings.
+---
+ include/v8.h      |   44 ++++++++++++++++++++++++++++++
+ src/api.cc        |   43 +++++++++++++++++++++++++++++
+ src/heap-inl.h    |    2 +
+ src/heap.cc       |    3 ++
+ src/objects-inl.h |    1 +
+ src/objects.cc    |   77 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
+ src/objects.h     |   15 +++++++++-
+ 7 files changed, 182 insertions(+), 3 deletions(-)
+
+diff --git a/include/v8.h b/include/v8.h
+index d15d024..bbd29e9 100644
+--- a/include/v8.h
++++ b/include/v8.h
+@@ -994,6 +994,48 @@ class String : public Primitive {
+   V8EXPORT int Utf8Length() const;
+
+   /**
++   * Returns the hash of this string.
++   */
++  V8EXPORT uint32_t Hash() const;
++
++  struct CompleteHashData {
++    CompleteHashData() : length(0), hash(0), symbol_id(0) {}
++    int length;
++    uint32_t hash;
++    uint32_t symbol_id;
++  };
++
++  /**
++   * Returns the "complete" hash of the string.  This is
++   * all the information about the string needed to implement
++   * a very efficient hash keyed on the string.
++   *
++   * The members of CompleteHashData are:
++   *    length: The length of the string.  Equivalent to Length()
++   *    hash: The hash of the string.  Equivalent to Hash()
++   *    symbol_id: If the string is a sequential symbol, the symbol
++   *        id, otherwise 0.  If the symbol ids of two strings are
++   *        the same (and non-zero) the two strings are identical.
++   *        If the symbol ids are different the strings may still be
++   *        identical, but an Equals() check must be performed.
++   */
++  V8EXPORT CompleteHashData CompleteHash() const;
++
++  /**
++   * Compute a hash value for the passed UTF16 string
++   * data.
++   */
++  V8EXPORT static uint32_t ComputeHash(uint16_t *string, int length);
++  V8EXPORT static uint32_t ComputeHash(char *string, int length);
++
++  /**
++   * Returns true if this string is equal to the external
++   * string data provided.
++   */
++  V8EXPORT bool Equals(uint16_t *string, int length);
++  V8EXPORT bool Equals(char *string, int length);
++
++  /**
+    * Write the contents of the string to an external buffer.
+    * If no arguments are given, expects the buffer to be large
+    * enough to hold the entire string and NULL terminator. Copies
+@@ -1023,6 +1065,8 @@ class String : public Primitive {
+     HINT_MANY_WRITES_EXPECTED = 1
+   };
+
++  V8EXPORT uint16_t GetCharacter(int index);
++
+   V8EXPORT int Write(uint16_t* buffer,
+                      int start = 0,
+                      int length = -1,
+diff --git a/src/api.cc b/src/api.cc
+index a2373cd..381935b 100644
+--- a/src/api.cc
++++ b/src/api.cc
+@@ -3284,6 +3284,49 @@ int String::Utf8Length() const {
+   return str->Utf8Length();
+ }
+
++uint32_t String::Hash() const {
++  i::Handle<i::String> str = Utils::OpenHandle(this);
++  if (IsDeadCheck(str->GetIsolate(), "v8::String::Hash()")) return 0;
++  return str->Hash();
++}
++
++String::CompleteHashData String::CompleteHash() const {
++  i::Handle<i::String> str = Utils::OpenHandle(this);
++  if (IsDeadCheck(str->GetIsolate(), "v8::String::CompleteHash()")) return CompleteHashData();
++  CompleteHashData result;
++  result.length = str->length();
++  result.hash = str->Hash();
++  if (str->IsSeqString())
++      result.symbol_id = i::SeqString::cast(*str)->symbol_id();
++  return result;
++}
++
++uint32_t String::ComputeHash(uint16_t *string, int length) {
++  return i::HashSequentialString<i::uc16>(string, length) >> i::String::kHashShift;
++}
++
++uint32_t String::ComputeHash(char *string, int length) {
++  return i::HashSequentialString<char>(string, length) >> i::String::kHashShift;
++}
++
++uint16_t String::GetCharacter(int index)
++{
++  i::Handle<i::String> str = Utils::OpenHandle(this);
++  return str->Get(index);
++}
++
++bool String::Equals(uint16_t *string, int length) {
++  i::Handle<i::String> str = Utils::OpenHandle(this);
++  if (IsDeadCheck(str->GetIsolate(), "v8::String::Equals()")) return 0;
++  return str->SlowEqualsExternal(string, length);
++}
++
++bool String::Equals(char *string, int length)
++{
++  i::Handle<i::String> str = Utils::OpenHandle(this);
++  if (IsDeadCheck(str->GetIsolate(), "v8::String::Equals()")) return 0;
++  return str->SlowEqualsExternal(string, length);
++}
+
+ int String::WriteUtf8(char* buffer,
+                       int capacity,
+diff --git a/src/heap-inl.h b/src/heap-inl.h
+index 99737ed..f4fce7b 100644
+--- a/src/heap-inl.h
++++ b/src/heap-inl.h
+@@ -93,6 +93,7 @@ MaybeObject* Heap::AllocateAsciiSymbol(Vector<const char> str,
+   String* answer = String::cast(result);
+   answer->set_length(str.length());
+   answer->set_hash_field(hash_field);
++  SeqString::cast(answer)->set_symbol_id(0);
+
+   ASSERT_EQ(size, answer->Size());
+
+@@ -126,6 +127,7 @@ MaybeObject* Heap::AllocateTwoByteSymbol(Vector<const uc16> str,
+   String* answer = String::cast(result);
+   answer->set_length(str.length());
+   answer->set_hash_field(hash_field);
++  SeqString::cast(answer)->set_symbol_id(0);
+
+   ASSERT_EQ(size, answer->Size());
+
+diff --git a/src/heap.cc b/src/heap.cc
+index 2b6c11f..930c97b 100644
+--- a/src/heap.cc
++++ b/src/heap.cc
+@@ -3519,6 +3519,7 @@ MaybeObject* Heap::AllocateInternalSymbol(unibrow::CharacterStream* buffer,
+   String* answer = String::cast(result);
+   answer->set_length(chars);
+   answer->set_hash_field(hash_field);
++  SeqString::cast(result)->set_symbol_id(0);
+
+   ASSERT_EQ(size, answer->Size());
+
+@@ -3561,6 +3562,7 @@ MaybeObject* Heap::AllocateRawAsciiString(int length, PretenureFlag pretenure) {
+   HeapObject::cast(result)->set_map(ascii_string_map());
+   String::cast(result)->set_length(length);
+   String::cast(result)->set_hash_field(String::kEmptyHashField);
++  SeqString::cast(result)->set_symbol_id(0);
+   ASSERT_EQ(size, HeapObject::cast(result)->Size());
+   return result;
+ }
+@@ -3596,6 +3598,7 @@ MaybeObject* Heap::AllocateRawTwoByteString(int length,
+   HeapObject::cast(result)->set_map(string_map());
+   String::cast(result)->set_length(length);
+   String::cast(result)->set_hash_field(String::kEmptyHashField);
++  SeqString::cast(result)->set_symbol_id(0);
+   ASSERT_EQ(size, HeapObject::cast(result)->Size());
+   return result;
+ }
+diff --git a/src/objects-inl.h b/src/objects-inl.h
+index 65aec5d..c82080d 100644
+--- a/src/objects-inl.h
++++ b/src/objects-inl.h
+@@ -1924,6 +1924,7 @@ INT_ACCESSORS(ExternalArray, length, kLengthOffset)
+
+
+ SMI_ACCESSORS(String, length, kLengthOffset)
++SMI_ACCESSORS(SeqString, symbol_id, kSymbolIdOffset)
+
+
+ uint32_t String::hash_field() {
+diff --git a/src/objects.cc b/src/objects.cc
+index df61956..dc4b260 100644
+--- a/src/objects.cc
++++ b/src/objects.cc
+@@ -5346,6 +5346,66 @@ static inline bool CompareStringContentsPartial(Isolate* isolate,
+   }
+ }
+
++bool String::SlowEqualsExternal(uc16 *string, int length) {
++  int len = this->length();
++  if (len != length) return false;
++  if (len == 0) return true;
++
++  // We know the strings are both non-empty. Compare the first chars
++  // before we try to flatten the strings.
++  if (this->Get(0) != string[0]) return false;
++
++  String* lhs = this->TryFlattenGetString();
++
++  if (lhs->IsFlat()) {
++    if (lhs->IsAsciiRepresentation()) {
++      Vector<const char> vec1 = lhs->ToAsciiVector();
++      VectorIterator<char> buf1(vec1);
++      VectorIterator<uc16> ib(string, length);
++      return CompareStringContents(&buf1, &ib);
++    } else {
++      Vector<const uc16> vec1 = lhs->ToUC16Vector();
++      Vector<const uc16> vec2(string, length);
++      return CompareRawStringContents(vec1, vec2);
++    }
++  } else {
++    Isolate* isolate = GetIsolate();
++    isolate->objects_string_compare_buffer_a()->Reset(0, lhs);
++    VectorIterator<uc16> ib(string, length);
++    return CompareStringContents(isolate->objects_string_compare_buffer_a(), &ib);
++  }
++}
++
++bool String::SlowEqualsExternal(char *string, int length)
++{
++  int len = this->length();
++  if (len != length) return false;
++  if (len == 0) return true;
++
++  // We know the strings are both non-empty. Compare the first chars
++  // before we try to flatten the strings.
++  if (this->Get(0) != string[0]) return false;
++
++  String* lhs = this->TryFlattenGetString();
++
++  if (StringShape(lhs).IsSequentialAscii()) {
++      const char* str1 = SeqAsciiString::cast(lhs)->GetChars();
++      return CompareRawStringContents(Vector<const char>(str1, len),
++                                      Vector<const char>(string, len));
++  }
++
++  if (lhs->IsFlat()) {
++      Vector<const uc16> vec1 = lhs->ToUC16Vector();
++      VectorIterator<const uc16> buf1(vec1);
++      VectorIterator<char> buf2(string, length);
++      return CompareStringContents(&buf1, &buf2);
++  } else {
++    Isolate* isolate = GetIsolate();
++    isolate->objects_string_compare_buffer_a()->Reset(0, lhs);
++    VectorIterator<char> ib(string, length);
++    return CompareStringContents(isolate->objects_string_compare_buffer_a(), &ib);
++  }
++}
+
+ bool String::SlowEquals(String* other) {
+   // Fast check: negative check with lengths.
+@@ -8655,9 +8715,24 @@ class AsciiSymbolKey : public SequentialSymbolKey<char> {
+
+   MaybeObject* AsObject() {
+     if (hash_field_ == 0) Hash();
+-    return HEAP->AllocateAsciiSymbol(string_, hash_field_);
++    MaybeObject *result = HEAP->AllocateAsciiSymbol(string_, hash_field_);
++    if (!result->IsFailure() && result->ToObjectUnchecked()->IsSeqString()) {
++        while (true) {
++            Atomic32 my_symbol_id = next_symbol_id;
++            if (my_symbol_id > Smi::kMaxValue)
++                break;
++            if (my_symbol_id == NoBarrier_CompareAndSwap(&next_symbol_id, my_symbol_id, my_symbol_id + 1)) {
++                SeqString::cast(result->ToObjectUnchecked())->set_symbol_id(my_symbol_id);
++                break;
++            }
++        }
++    }
++    return result;
+   }
++
++  static Atomic32 next_symbol_id;
+ };
++Atomic32 AsciiSymbolKey::next_symbol_id = 1;
+
+
+ class TwoByteSymbolKey : public SequentialSymbolKey<uc16> {
+diff --git a/src/objects.h b/src/objects.h
+index e966b3d..6e26f57 100644
+--- a/src/objects.h
++++ b/src/objects.h
+@@ -5359,6 +5359,9 @@ class String: public HeapObject {
+   bool IsAsciiEqualTo(Vector<const char> str);
+   bool IsTwoByteEqualTo(Vector<const uc16> str);
+
++  bool SlowEqualsExternal(uc16 *string, int length);
++  bool SlowEqualsExternal(char *string, int length);
++
+   // Return a UTF8 representation of the string.  The string is null
+   // terminated but may optionally contain nulls.  Length is returned
+   // in length_output if length_output is not a null pointer  The string
+@@ -5610,9 +5613,17 @@ class String: public HeapObject {
+ class SeqString: public String {
+  public:
+
++  // Get and set the symbol id of the string
++  inline int symbol_id();
++  inline void set_symbol_id(int value);
++
+   // Casting.
+   static inline SeqString* cast(Object* obj);
+
++  // Layout description.
++  static const int kSymbolIdOffset = String::kSize;
++  static const int kSize = kSymbolIdOffset + kPointerSize;
++
+  private:
+   DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString);
+ };
+@@ -5647,7 +5658,7 @@ class SeqAsciiString: public SeqString {
+   }
+
+   // Layout description.
+-  static const int kHeaderSize = String::kSize;
++  static const int kHeaderSize = SeqString::kSize;
+   static const int kAlignedSize = POINTER_SIZE_ALIGN(kHeaderSize);
+
+   // Maximal memory usage for a single sequential ASCII string.
+@@ -5701,7 +5712,7 @@ class SeqTwoByteString: public SeqString {
+   }
+
+   // Layout description.
+-  static const int kHeaderSize = String::kSize;
++  static const int kHeaderSize = SeqString::kSize;
+   static const int kAlignedSize = POINTER_SIZE_ALIGN(kHeaderSize);
+
+   // Maximal memory usage for a single sequential two-byte string.
+--
+1.7.2.3
+