v8/ChangeLog

2008-12-03: Version 0.4.5

        Added experimental API support for allocating V8 symbols as
        external strings.

        Fixed bugs in debugging support on ARM.

        Changed eval implementation to correctly detect whether or not a
        call to eval is aliased.

        Fixed bug caused by a combination of the compilation cache and
        dictionary probing in native code.  The bug caused us to sometimes
        call functions that had not yet been compiled.

        Added platform support for FreeBSD.

        Added support for building V8 on Windows with either the shared or
        static version of MSVCRT
        
        Added the v8::jscre namespace around the jscre functions to avoid
        link errors (duplicate symbols) when building Google Chrome.

        Added support for calling a JavaScript function with the current
        debugger execution context as its argument to the debugger
        interface.

        Changed the type of names of counters from wchar_t to char.

        Changed the Windows system call used to compute daylight savings
        time.  The system call that we used to use became four times
        slower on WinXP SP3.

        Added support in the d8 developer shell for memory-mapped counters
        and added a stats-viewer tool.

        Fixed bug in upper/lower case mappings (issue 149).


2008-11-17: Version 0.4.4

        Reduced code size by using shorter instruction encoding when
        possible.

        Added a --help option to the shell sample and to the d8 shell.

        Added visual studio project files for building the ARM simulator.

        Fixed a number of ARM simulator issues.

        Fixed bug in out-of-memory handling on ARM.

        Implemented shell support for passing arguments to a script from
        the command line.

        Fixed bug in date code that made certain date functions return -0
        instead of 0 for dates before the epoch.

        Restricted applications of eval so it can only be used in the
        context of the associated global object.

        Treat byte-order marks as whitespace characters.
        
        
2008-11-04: Version 0.4.3

        Added support for API accessors that prohibit overwriting by
        accessors defined in JavaScript code by using __defineGetter__ and
        __defineSetter__.

        Improved handling of conditionals in test status files.

        Introduced access control in propertyIsEnumerable.

        Improved performance of some string operations by caching
        information about the type of the string between operations.

        Fixed bug in fast-case code for switch statements that only have
        integer labels.
        

2008-10-30: Version 0.4.2

        Improved performance of Array.prototype.concat by moving the
        implementation to C++ (issue 123).

        Fixed heap growth policy to avoid growing old space to its maximum
        capacity before doing a garbage collection and fixed issue that
        would lead to artificial out of memory situations (issue 129).

        Fixed Date.prototype.toLocaleDateString to return the date in the
        same format as WebKit.

        Added missing initialization checks to debugger API.

        Added removing of unused maps during GC.


2008-10-28: Version 0.4.1

        Added caching of RegExp data in compilation cache.

        Added Visual Studio project file for d8 shell.

        Fixed function call performance regression introduced in version
        0.4.0 when splitting the global object in two parts (issue 120).

        Fixed issue 131 by checking for empty handles before throwing and
        reporting exceptions.


2008-10-23: Version 0.4.0

        Split the global object into two parts: The state holding global
        object and the global object proxy.

        Fixed bug that affected the value of an assignment to an element
        in certain cases (issue 116).

        Added GetPropertyNames functionality (issue 33) and extra Date
        functions (issue 77) to the API.

        Changed WeakReferenceCallback to take a Persistent<Value> instead
        of a Persistent<Object> (issue 101).

        Fixed issues with message reporting for exceptions in try-finally
        blocks (issues 73 and 75).

        Optimized flattening of strings and string equality checking. 

        Improved Boyer-Moore implementation for faster indexOf operations.

        Added development shell (d8) which includes counters and
        completion support.

        Fixed problem with the receiver passed to functions called from
        eval (issue 124).


2008-10-16: Version 0.3.5

        Improved string hash-code distribution by excluding bit-field bits
        from the hash-code.

        Changed string search algorithm used in indexOf from KMP to
        Boyer-Moore.

        Improved the generated code for the instanceof operator.

        Improved performance of slow-case string equality checks by
        specializing the code based on the string representation.

        Improve the handling of out-of-memory situations (issue 70).

        Improved performance of strict equality checks.

        Improved profiler output to make it easier to see anonymous
        functions.

        Improved performance of slow-case keyed loads.

        Improved property access performance by allocating a number of
        properties in the front object.

        Changed the toString behavior on the built-in object constructors
        to print [native code] instead of the actual source.  Some web
        applications do not like constructors with complex toString
        results.
        

2008-10-06: Version 0.3.4

        Changed Array.prototype.sort to use quick sort.

        Fixed code generation issue where leaving a finally block with
        break or continue would accumulate elements on the expression
        stack (issue 86).

        Made sure that the name accessor on functions returns the expected
        names for builtin JavaScript functions and C++ callback functions.

        Added fast case code for extending the property storage array of
        JavaScript objects.

        Ported switch statement optimizations introduced in version 0.3.3
        to the ARM code generator.

        Allowed GCC to use strict-aliasing rules when compiling.

        Improved performance of arguments object allocation by taking care
        of arguments adaptor frames in the generated code.

        Updated the V8 benchmark suite to version 2.


2008-09-25: Version 0.3.3

        Improved handling of relocation information to enable more
        peep-hole optimizations.

        Optimized switch statements where all labels are constant small
        integers.

        Optimized String.prototype.indexOf for common cases.

        Fixed more build issues (issue 80).

        Fixed a couple of profiler issues.

        Fixed bug where the body of a function created using the Function
        constructor was not allowed to end with a single-line comment
        (issue 85).

        Improved handling of object literals by canonicalizing object
        literal maps.  This will allow JSON objects with the same set of
        properties to share the same map making inline caching work better
        for JSON objects.
        

2008-09-17: Version 0.3.2

        Generalized the EvalCache into a CompilationCache and enabled it
        for scripts too.  The current strategy is to retire all entries
        whenever a mark-sweep collection is started.

        Fixed bug where switch statements containing only a default case
        would lead to an unbalanced stack (issue 69).

        Fixed bug that made access to the function in a named function
        expression impossible in certain situations (issue 24).

        Fixed even more build issues.

        Optimized calling conventions on ARM.  The conventions on ARM and
        IA-32 now match.

        Removed static initializers for flags and counters.

        Improved inline caching behavior for uncommon cases where lazily
        loading Date and RegExp code could force certain code paths go
        megamorphic.

        Removed arguments adaption for builtins written in C++.  This
        makes Array.prototype.push and Array.prototype.pop slightly
        faster.


2008-09-11: Version 0.3.1

        Fixed a number of build issues.

        Fixed problem with missing I-cache flusing on ARM.

        Changed space layout in memory management by splitting up
        code space into old data space and code space.

        Added utf-8 conversion support to the API (issue 57).

        Optimized repeated calls to eval with the same strings.  These
        repeated calls are common in web applications.

        Added Xcode project file.

        Optimized a couple of Array operation.

        Fixed parser bug by checking for end-of-string when parsing break
        and continue (issue 35).

        Fixed problem where asian characters were not categorized as
        letters.

        Fixed bug that disallowed calling functions fetched from an array
        using a string as an array index (issue 32).

        Fixed bug where the internal field count on object templates were
        sometimes ignored (issue 54).

        Added -f option to the shell sample for compatibility with other
        engines (issue 18).

        Added source info to TryCatches in the API.

        Fixed problem where the seed for the random number generator was
        clipped in a double to unsigned int conversion.

        Fixed bug where cons string symbols were sometimes converted to
        non-symbol flat strings during GC.

        Fixed bug in error reporting when attempting to convert null to an
        object.
        
        
2008-09-04: Version 0.3.0

        Added support for running tests on the ARM simulator.

        Fixed bug in the 'in' operator where negative indices were not
        treated correctly.

        Fixed build issues on gcc-4.3.1.

        Changed Date.prototype.toLocaleTimeString to not print the
        timezone part of the time.

        Renamed debug.h to v8-debug.h to reduce the risk of name conflicts
        with user code.


2008-09-02: Version 0.2.5

        Renamed the top level directory 'public' to 'include'.

        Added 'env' option to the SCons build scripts to support
        overriding the ENV part of the build environment.  This is mostly
        to support Windows builds in cases where SCons cannot find the
        correct paths to the Windows SDK, as these paths cannot be passed
        through shell environment variables.

        Enabled "Buffer Security Check" on for the Windows SCons build and
        added the linker option /OPT:ICF as an optimization.

        Added the V8 benchmark suite to the repository.


2008-09-01: Version 0.2.4

        Included mjsunit JavaScript test suite and C++ unit tests.

        Changed the shell sample to not print the result of executing a
        script provided on the command line.

        Fixed issue when building samples on Windows using a shared V8
        library.  Added visibility option on Linux build which makes the
        generated library 18% smaller.

        Changed build system to accept multiple build modes in one build
        and generate separate objects, libraries and executables for each
        mode.

        Removed deferred negation optimization (a * -b => -(a * b)) since
        this visibly changes operand conversion order.

        Improved parsing performance by introducing stack guard in
        preparsing.  Without a stack guard preparsing always bails out
        with stack overflow.

        Changed shell sample to take flags directly from the command-line.
        Added API call that implements this.

        Added load, quit and version functions to the shell sample so it's
        easier to run benchmarks and tests.

        Fixed issue with building samples and cctests on 64-bit machines.

        Fixed bug in the runtime system where the prototype chain was not
        always searched for a setter when setting a property that does not
        exist locally.
        

2008-08-14: Version 0.2.3

        Improved performance of garbage collection by moving the
        function that updates pointers during compacting collection
        into the updating visitor.  This gives the compiler a better
        chance to inline and avoid a function call per (potential)
        pointer.

        Extended the shell sample with a --runtime-flags option.

        Added Visual Studio project files for the shell.cc and
        process.cc samples.


2008-08-13: Version 0.2.2

        Improved performance of garbage collection by changing the way
        we use the marking stack in the event of stack overflow during
        full garbage collection and by changing the way we mark roots.

        Cleaned up ARM version by removing top of stack caching and by
        introducing push/pop elimination.

        Cleaned up the way runtime functions are called to allow
        runtime calls with no arguments.

        Changed Windows build options to make sure that exceptions are
        disabled and that optimization flags are enabled.

        Added first version of Visual Studio project files.


2008-08-06: Version 0.2.1

        Improved performance of unary addition by avoiding runtime calls.

        Fixed the handling of '>' and '<=' to use right-to-left conversion
        and left-to-right evaluation as specified by ECMA-262.

        Fixed a branch elimination bug on the ARM platform where incorrect
        code was generated because of overly aggressive branch
        elimination.

        Improved performance of code that repeatedly assigns the same
        function to the same property of different objects with the same
        map.

        Untangled DEBUG and ENABLE_DISASSEMBLER defines.  The disassembler
        no longer expects DEBUG to be defined.

        Added platform-nullos.cc to serve as the basis for new platform
        implementations.


2008-07-30: Version 0.2.0

        Changed all text files to have native svn:eol-style.

        Added a few samples and support for building them. The samples
        include a simple shell that can be used to benchmark and test V8.

        Changed V8::GetVersion to return the version as a string.

        Added source for lazily loaded scripts to snapshots and made
        serialization non-destructive.

        Improved ARM support by fixing the write barrier code to use
        aligned loads and stores and by removing premature locals
        optimization that relied on broken support for callee-saved
        registers (removed).

        Refactored the code for marking live objects during garbage
        collection and the code for allocating objects in paged
        spaces. Introduced an abstraction for the map word of a heap-
        allocated object and changed the memory allocator to allocate
        executable memory only for spaces that may contain code objects.

        Moved StringBuilder to utils.h and ScopedLock to platform.h, where
        they can be used by debugging and logging modules. Added
        thread-safe message queues for dealing with debugger events.

        Fixed the source code reported by toString for certain builtin
        empty functions and made sure that the prototype property of a
        function is enumerable.

        Improved performance of converting values to condition flags in
        generated code.

        Merged disassembler-{arch} files.


2008-07-28: Version 0.1.4

        Added support for storing JavaScript stack traces in a stack
        allocated buffer to make it visible in shallow core dumps.
        Controlled by the --preallocate-message-memory flag which is
        disabled by default.


2008-07-25: Version 0.1.3

        Fixed bug in JSObject::GetPropertyAttributePostInterceptor where
        map transitions would count as properties.

        Allowed aliased eval invocations by treating them as evals in the
        global context. This may change in the future.

        Added support for accessing the last entered context through the
        API and renamed Context::Current to Context::GetCurrent and
        Context::GetSecurityContext to Context::GetCurrentSecurityContext.

        Fixed bug in the debugger that would cause the debugger scripts to
        be recursively loaded and changed all disabling of interrupts to
        be block-structured.

        Made snapshot data read-only to allow it to be more easily shared
        across multiple users of V8 when linked as a shared library.


2008-07-16: Version 0.1.2

        Fixed building on Mac OS X by recognizing i386 and friends as
        IA-32 platforms.

        Added propagation of stack overflow exceptions that occur while
        compiling nested functions.

        Improved debugger with support for recursive break points and
        handling of exceptions that occur in the debugger JavaScript code.

        Renamed GetInternal to GetInternalField and SetInternal to
        SetInternalField in the API and moved InternalFieldCount and
        SetInternalFieldCount from FunctionTemplate to ObjectTemplate.


2008-07-09: Version 0.1.1

        Fixed bug in stack overflow check code for IA-32 targets where a
        non-tagged value in register eax was pushed to the stack.

        Fixed potential quadratic behavior when converting strings to
        numbers.

        Fixed bug where the return value from Object::SetProperty could
        end up being the property holder instead of the written value.

        Improved debugger support by allowing nested break points and by
        dealing with stack-overflows when compiling functions before
        setting break points in them.


2008-07-03: Version 0.1.0

        Initial export.