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List of user-visible changes in GNU Smalltalk
NEWS FROM 2.3.4 TO 2.3.5
o Added more examples of continuations.
o Fixed a floating-point accuracy problem in the test suite.
o Fixed a 64-bit cleanliness problem in the GDBM bindings.
o Generational GC enabled on x86_64.
o Support for writing a block with arguments and no statements
as [ :a :b ] in addition to [ :a :b | ].
o The StreamFilter.st example, which provided lookahead, filtering,
concatenation and other kinds of manipulation for Streams, has been
promoted into the default image.
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NEWS FROM 2.3.3 TO 2.3.4
o Behavior>>#evaluate: and MethodDictionary>>#removeAt:ifAbsent: would
cause the method dictionary's size to double. This caused sometimes
spurious failures in floatmath.st.
o Fixed bug in LargeInteger division on systems not equipped with GMP.
o Fixed bug in socket #nextHunk implementation, which lost the first
or second byte in the input buffer.
o Fixed paths in the image when "make DESTDIR" was used.
o Fixed implementation of Dictionary>>#addAll:, and fixed Integer>>#binomial:
when the argument is 0 or self.
o Fixed various minor bugs and imprecisions in the documentation.
o Improvements to the ancillary scripts gst-load and gst-sunit. In
particular, a package can describe the classes that constitute its
testsuite, and gst-sunit allows to quickly run the testsuite for a
package.
o Improvements to the test suite. Several of the modules included with
GNU Smalltalk are tested. The testsuite is now written using Autotest.
o Some libffi files (for IA64 and PA) were missing from the distribution.
o Upgraded libsigsegv, for improved Mac OS X on Intel support
o zlib bindings provided in package ZLib.
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NEWS FROM 2.3.2 TO 2.3.3
o Introduced the --with-imagedir configure option to specify the directory
used for the image.
o The manual was not properly generated in version 2.3.2.
o Removed text relocations from the virtual machine's shared library.
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NEWS FROM 2.3.1 TO 2.3.2
o #copyFrom:to: is uniformly 0-based for all Streams (unlike in Collections),
because a Stream has 0-based #position and #position: methods.
o Fixed many floating point rounding bugs in LargeIntegers and Fractions,
thanks to Nicolas Cellier.
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NEWS FROM 2.3 TO 2.3.1
o configure does not lock up when the system emacs is XEmacs and does not
include both the comint package and the package's source code.
o Fixed a garbage collection bug that typically occurred when installing
GNU Smalltalk, or when launching the installed image.
o gst-package honors the INSTALL command found by configure.
o gst-config does not "forget" to prefix the library directories with -L.
o Segmentation violations on large integer operations (on 64-bit hosts)
were fixed.
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NEWS FROM 2.2 TO 2.3
IMPORTANT: GNU Smalltalk now adds an explicit exception to the GNU GPL
license, allowing the programs running under the virtual machine to use
a GPL-incompatible license. This exception is used both by the
virtual machine and by the library bindings included in GNU Smalltalk.
This clears gray areas when a Smalltalk program is using functions
in the external library bindings via dynamic linking and the foreign
function call interface (C call-outs).
o C call-outs returning #void now return self rather than nil.
Performance of code heavily using C call-outs has improved.
o FileStreams can now use pwrite for more efficient operation on files
opened for read/write, and will do many less gratuitous lseek
operations. pread will also be used by FileStream>>#copyFrom:to:.
The number of system calls issued when generating the documentation,
for example, is reduced by a third.
o Fixed bug in methods containing both -0.0 and 0.0 (positive and negative
floating-point zero).
o Fixed bug in Directory class>>#create:, that could not create a
directory relative to the current directory.
o Fixed bug in File>>#touch, which did not work really. There are also
methods to modify a file's atime and mtime.
o Fixed bug in SortedCollection. After #removeAtIndex:, adds would leave
the collection unordered.
o Fixed many more bugs.
o Introduced a method to efficiently convert a WriteStream into a ReadStream.
It is called #readStream and makes WriteStream more polymorphic with String.
o Introduced two more class shapes, #character and #utf32, that can be used
for String and UnicodeString.
o More reliable detection of at-end-of-file condition for pipes, TTYs,
and so on (especially on Mac OS X), and of sockets closed by the peer.
Due to incompatibilities between various OSes, you are advised to test
end-of-stream conditions *before* rather than after reading a character
from stdin. In 2.2, either way would work, but serious bugs were
found on Mac OS X unless stdin was redirected from a file.
o Moved gdk_draw_ functions to GdkDrawable.
o New goodie to parse the command line. Look at the documentation for
the Getopt class and for SystemDictionary>>#arguments:do:.
o New example, lazy collections. When loaded, #select:, #reject: and
#collect: do not create a new collection unless necessary. Idioms like
(a select: [ :each | ... ]) do: [ : each | ... ]
or
a := a select: [ :each | ... ].
a := a reject: [ :each | ... ].
a := a select: [ :each | ... ].
^a size
can be much faster when this example is loaded.
o Regular expressions are now included in the default image. The interface
is now definitive and is similar to 2.2. The concrete classes for
RegexResults are in a private namespace (since the user need not
instantiate them anyway). Right now, regular expressions are only
usable for String objects (see Unicode support below). This may
change in the future.
o The backtraces now omit again the internal methods in the exception
handling system.
o The class above which super-send bytecodes start searching is now embedded
in the bytecode stream. This provides the infrastructure to implement
'here' as in Smalltalk/X or 'self.Foo b' to execute the Foo>>#b method
(these possible extensions have not been implemented).
o The header files compile cleanly with a C++ compiler. For the occasion,
the preferred name of the old `mst_Object' has changed to `gst_object'.
o Various speedups.
Unicode support:
o Characters above 127 are no longer used to represent extended ASCII
characters. Instead, they are only used to represent a byte in
the encoding of the Unicode characters from 128 on. To create
them use the Blue Book method Character class>>#value:.
To represent Unicode characters above 127 use the (ANSI Smalltalk)
Character class>>#codePoint: method. Note that these characters
*cannot* be shown on a stream with #nextPut: (use #display: instead)
nor compared with #== (use #= instead).
Character literals like $+ or $A are guaranteed to create normal
"Character" objects, for which you can safely use #nextPut:. Right
now, these are valid only for characters between 0 and 127. To create
Character literals for unicode characters, use the new syntax to
express characters using their Unicode code point. This may be
extended in the future to support Unicode character literals.
A ``safe'' way to obtain the character whose encoding is between
128 and 255 is this (which requires the Iconv module to be loaded):
##('<your character>' asUnicodeString first)
(This snippet has no shortcut by design because, in general, converting
a Character to a UnicodeCharacter is not a well-defined operation).
o New UnicodeCharacter and UnicodeString classes. These new classes
can also be passed to and received from C functions. See the
manual for more information.
o New syntax $<13> to express characters using their Unicode code point.
As anticipated, this syntax will create instances of the new UnicodeCharacter
class when the number is > 127.
o Part of the I18N module was separated into the Iconv module, which
provides support for printing Unicode characters and strings correctly.
Other goodies:
o NCurses bindings, contributed by Brad Watson.
-----------------------------------------------------------------------------
NEWS FROM 2.1.12 TO 2.2
Scripting improvements:
o A sharp-bang sequence at the beginning of a file is parsed as a
one-line comment.
o Provides an "-f" option (long option "--file") to be used in a #! line,
as in "#! /usr/bin/env gst -f", which has the same effect of -Q,
processing the file indicated by the option's argument, and passing
the rest of the command line to GNU Smalltalk. In other words, the
two invocations that follow are equivalent:
gst -f script.st ARG1 ARG2
gst script.st -Qa ARG1 ARG2
o Load.st installed as gst-load, Reload.st installed as gst-reload,
Test.st installed as gst-sunit.
VM changes:
o Can define subclasses of CompiledMethod and have a method invoked on
the instances whenever the method is called.
o Can pass a "void **" to C using the #cObjectPtr parameter specifier
(previously undocumented and broken).
o The #class method can be overridden. This is useful for example
for debuggers and proxies.
o Code for decoding/interpreting the bytecode set is for the most part
automatically generated. Take a look at the ``genbc'' and ``genvm''
programs if you are going to write an high performance interpreter, and
write to the mailing list for any information on them or on the other
program ``superops'' (this one is much more specialized).
o CompiledBlocks and CompiledMethods are read-only.
o Dollars are allowed in the middle of identifiers and method names.
This is unportable, so do not abuse it. As with underscores, it is not
possible to use them at the beginning of an identifier or method name.
o Fixed bug that caused the compiler to accept duplicate argument or
temporary names.
o GCC needed to compile GNU Smalltalk.
o gst_smalltalk_args accepts a const char **.
o Improved clarity and portability using intptr_t, size_t and ptrdiff_t
more widely and wisely.
o Indexed instance variables can be 8-bit and 16-bit, signed and unsigned
integers; or they can be 32-bit and 64-bit, signed integers and unsigned
integers and floating point values; or objects of course. Previously
the only three possibilities were objects, 8-bit unsigned ints, and
pointer-sized unsigned ints.
o Instance variables are scanned backwards: if a subclass declares an
instance variable with the same name of the superclass, it wins when
compiling code in the subclass (fixes the so-called "fragile subclass"
problem).
o Keywords and parameters need not be separated by a space (as in
`self x: y z:w').
o New bytecode set. This is a significant departure from the Blue Book's
instruction set, and it improves performance by ~20%. Over 150 common
bytecode sequences are optimized, saving on dispatching overhead and
minimizing the cost of decoding arguments.
o Options -l and -L (--log-changes and --log-file) are no more. The
change log is not useful outside the GUI, while inside the GUI it
ought to be maintained by the GUI itself.
o Option -s is no more. It was made the default in 2.1.5.
o Passing floating-point arguments to C works.
o Prefetching instructions are used wherever supported (Alpha, SPARC,
PPC, AMD K6 or newer, Intel PIII or newer, all with GCC 3.2). This
speeds up the startup by up to 20%.
o Instances of subclasses of CompiledBlock and CompiledMethod can be
created using the same primitive that creates CompiledBlocks and
CompiledMethods, but sent to the subclass.
o Several important bug fixes in event handling and asynchronous file
input/output.
o Subclasses of MethodInfo can be used as the descriptors for CompiledMethod
objects.
o Two-character binary messages ending with a minus are scanned differently
if followed by a number: "1+-2" is now read as "1 + -2", not "1 +- 2".
This is what you would usually expect; however, including spaces explicitly
is recommended.
o When GCC 3.3 or later is used, a shared library is also built. The
code has been to some extent optimized to make this less expensive, but
the shared library still has a 5-10% performance hit. Note that the x86
shared library is undebuggable (-fomit-frame-pointer) with GCC < 4.0
because of the dearth of registers. The installed virtual machine is not
linked to the shared library for optimal speed.
o Wider set of operations available to modules that plug into GNU Smalltalk,
including access to system classes, queries on the method dictionaries,
and access to indexed instance variables.
Smalltalk changes:
o CLongDouble class allows one to access long doubles; long doubles are
supported by CStruct, Memory and ByteArray as well.
o CompiledCode>>#literalsDo: does what CompiledCode>>#allLiteralsDo:
used to do. CompiledCode>>#allLiteralsDo: recurses into literal
arrays.
o Glorp, a layer for mapping objects to relational databases, is provided
and integrated with the MySQL driver.
o GNU Smalltalk includes a mechanism for defining security policies
on a class-by-class basis. See below for more information.
o Interval can return a #first and #last even if the Interval is empty.
These are the start and stop object that it was created with. The
private methods #start, #stop and #step have thus been superseded by
#first, #last and #increment.
o #min: and #max: always return a NaN when one of the two operands is
a NaN; previously they would always return the other operand.
o New syntax for C call-outs, can be transparently filed out from the
image and then filed back in. See the documentation or the
kernel/CFuncs.st file for more information.
o PackageLoader can be told the namespace in which to load the package.
Most package loading scripts are now no longer necessary or can be
reduced to simple initialization duties.
o #raisedToInteger: is better optimized and does the minimum number of
multiplications for exponents up to 256.
o SequenceableCollection has a more efficient implementation of #fold:,
as well as #second, #third, and #fourth (and I'm going to stop here!).
o #return and #return: now reinstate exception handlers, which will
therefore be active while executing pending #ensure: or #ifCurtailed:
blocks.
o Stored CompiledBlocks into the method's literal frame for non-clean
blocks, and turned #blockCopy: into a `make dirty block' bytecode
without introducing a method of unclear utility. This is a little
faster and (consistently) saves around 1% on image files.
o The syntax for primitives has been generalized into a "method attribute"
mechanism; pragmas are accessible through methods in CompiledMethod.
o The thisContext variable is compiled as a message send like
"ContextPart thisContext".
o When a send to super fails, #doesNotUnderstand: is also sent to super
and not to self. This change is experimental; these semantics look more
coherent to me. As a result (think about it...) sends to super from a
root class are now forbidden.
o When a non-existing message is sent with the wrong number of arguments
(using #perform:), #doesNotUnderstand: is invoked. In the past, the
wrong number of arguments error would have been printed. The reason
for this is to allow selector names that would be invalid for the
Smalltalk language.
Work in progress:
o Blox-GTK interface, to use the browser under Gtk+. Currently, only
the browser works; to try it, configure with --enable-gtk=blox or
load the BloxGTK package. Thanks to Robert Collins.
o GNU Smalltalk now supports executing (some) Java programs. See the
info documentation for more information. The class library is based
on GCJ 3.4, but should be reasonably upwards-compatible. There is no
AWT nor JNI support, and it is not planned; networking, reflection and
serialization are not there but should be added in the future.
Overview of the security mechanism:
o Implemented class-level permissions. Each class can have its own
permission set, and if this is not trivial (all-allowed) the class
is marked untrusted; then instances of that class, as well as contexts
that have at least an untrusted object as the receiver in the sender
chain, are considered untrusted. In the future, security checks will
be made for untrusted objects in such methods as
C call-outs [#memoryAccess]
CObject class>>#alloc: [#memoryAccess]
CObject class>>#alloc:type: [#memoryAccess]
CObject>>#free [#memoryAccess]
CObject>>#at: [#memoryAccess]
CObject>>#at:put: [#memoryAccess]
Memory>>#at: [#memoryAccess]
Memory>>#at:put: [#memoryAccess]
FileDescriptor>>#fileOp:... [#io]
ObjectMemory>>#snapshot: [#io]
ObjectMemory>>#quit: [#system]
ObjectMemory>>#abort [#system]
ObjectMemory>>#setSpaceGrowRate: [#system]
ObjectMemory>>#setSmoothingFactor: [#system]
ObjectMemory>>#setGrowThresholdPercent: [#system]
ObjectMemory>>#setBigObjectThreshold: [#system]
ObjectMemory>>#growTo: [#system]
Object>>#makeUntrusted: [#securityManagement]
Object>>#instVarAt: [#debugging]
Object>>#instVarAt:put: [#debugging]
Object>>#perform:... [#debugging]
Object>>#changeClassTo: [#debugging]
Process>>#suspend [#processManagement]
Process>>#resume [#processManagement]
UndefinedObject>>#subclass:... etc... [#system]
Class>>#subclass:... etc... (mutation) [#system]
Metaclass>>#instanceVariableNames: [#system]
MethodDictionary>>#at:put: [#system]
o Instance variables of an untrusted class that are declared by a trusted
class are read-only. This is necessary to avoid that a misbehaving
class method screws up the instance variables of Behavior that are known
to the VM.
o Methods are verified.
o Permissions can be granted by a method to its callees if the method's
definition class owns those permissions. This can be used to invoke
trusted C call-outs.
o Primitives cannot be declared for untrusted objects (this might be
fine-grained in the future).
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NEWS IN 2.1.12
This is a bugfix release. It fixes several problems on 64-bit systems.
-----------------------------------------------------------------------------
NEWS IN 2.1.11
This is a bugfix release.
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NEWS IN 2.1.10
This is a bugfix release, but with this visible change:
o PackageLoader supports loading package source code from multiple
directories.
Directory packages.xml is in Directories looked in
/usr/share/smalltalk /usr/share/smalltalk
parent of local kernel directory, if any
image directory
parent of local kernel directory parent of local kernel directory
image directory
image directory image directory
o Directory>>#append:to: supports passing an absolute path as the file
name (first argument). In this case, the file name itself is returned.
This release works under MacOS X 10.3 and 10.4 as well. It also works
around bugs in MacOS X Tiger's poll function.
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