file_id.diz
Crinkler - compressing linker for Windows
Copyright 2005-2009 Aske Simon Christensen and Rune L. H. Stubbe.
DISTRIBUTION
Crinkler is freeware. You may distribute it freely, as long as the
Crinkler executable and all accompanying documentation files are kept
together and intact. You may not distribute modified versions or any
kind of derived work based on Crinkler or its documentation. You may
not include Crinkler or its documentation in any other archive or
bundle.
USE AND AUTHOR RIGHTS
You may use Crinkler for any non-commercial purpose. All output
produced by Crinkler (executable files, HTML compression reports and
other textual output) is to be considered the original works of you as
a user of Crinkler. Such works are not covered by any restrictions by
this license, except that such works must not be used for any safety
critical purpose.
NO WARRANTY
Crinkler comes with no warranties of any kind. Crinkler is
experimental software that relies on many undocumented features of the
Windows PE loader. It has been created with the sole purpose of
producing tiny executable files that may or may not work as intended
on current and/or future versions of Windows.
LICENSE OF DISTORM
Crinkler uses the BSD-licensed diStorm disassembler library for
producing disassembly output of the compressed code. The license for
diStorm requires that the license below is included with derivative
works. The license below applies only to diStorm and not to Crinkler
as a whole.
:[diStorm64}:
The ultimate disassembler library.
Copyright (c) 2003,2004,2005,2006,2007,2008, Gil Dabah
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
* Neither the name of the diStorm nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
CRINKLER - Compressing linker for Windows specialized for 4k intros
Aske Simon Christensen "Blueberry/Loonies"
Rune L. H. Stubbe "Mentor/TBC"
Version 1.1a (January 14, 2009)
VERSION HISTORY
---------------
14.01.09: 1.1a: Fixed /TRUNCATEFLOATS crashing in some cases.
Improved /ORDERTRIES estimation when call transform is used.
Sometimes sections were misplaced in the HTML report.
Various improvements to the HTML report.
The /FIX option can input and output to the same file.
Helpful error messages for various unsupported features.
Prefer a custom entry point to a standard library one.
New section in the manual about runtime libraries.
12.01.08: 1.1: Support for weak externals (virtual C++ destructors).
Fixed compatibility with Data Execution Prevention.
/REPORT option for a colorful HTML compression report.
/TRUNCATEFLOATS option to mutilate float constants.
/SAFEIMPORT is now default, disabled with /UNSAFEIMPORT.
Slightly smaller overhead if range importing is not used.
Fixed some problems with compressing very small files.
/VERBOSE:FUNCTIONS removed, as it is subsumed by /REPORT.
Remaining /VERBOSE options renamed to /PRINT.
Maximum number of ORDERTRIES increased to 100000.
07.01.07: 1.0a: New /VERBOSE:FUNCTIONS options to sort the functions.
Various verbose output fixes.
Various crash fixes.
A fix to the /FIX Crinkler version recognizer.
27.12.06: 1.0: Output EXE files are now Windows Vista compatible.
Compression tweak for greatly improved compression ratio.
Much faster compression.
Automatically takes advantage of multiple processors.
Improved Visual Studio 2005 integration.
/COMPMODE:INSTANT option for very quick compression.
/ORDERTRIES option to try out different section orderings.
/SAFEIMPORT option to insert a check for nonexisting DLLs.
/PROGRESSGUI option for a graphical progress bar.
/REPLACEDLL option to replace one DLL with another.
/FIX option to fix compatibility problems of older versions.
09.02.06: 0.4a: Fixed linker crash problem with blank member entries
in some library files (such as glut32).
The /PRIORITY option was not mentioned in the
commandline usage help.
18.12.05: 0.4: Changed header and import code to make output EXE files
compatible with 64-bit versions of Windows.
Fixed a bug in the ordinal range import mechanism.
Added a switch to control the process priority.
Added a warning for range import of an unused DLL.
Some more header squeezing.
31.10.05: 0.3: Output EXE files are now Windows 2000 compatible.
Added a number of verbose options to output useful
information about the program being compressed.
Added an option for transforming function calls to
use absolute offsets to improve compression.
Fixed a bug in the linker regarding identically named
sections.
Fixed a potential crash bug in the linker.
Various small tweaks and optimizations.
23.07.05: 0.2: Fixed bug in the decompressor.
Changed the behaviour of the /CRINKLER option.
Added timing to the progress bars.
Some updates to the manual and usage description.
21.07.05: 0.1: First release.
BACKGROUND
----------
Ever since the concept of size-limited demo competitions was
introduced in the early 1990's (and before that as well), people have
been using executable file compressors to reduce the size of their
final executables. An executable file compressor is a program that
takes as input an executable file and produces a new executable file
which has the same behaviour as the original one but is (hopefully)
smaller.
The usual technique employed by executable file compressors is to
compress the contents of the executable file using some general
purpose data compression method and prepend to this compressed data a
small piece of code (the decompressor) which decompresses the contents
into memory in such a way that it looks to the code as if the original
executable file had been loaded into memory in the normal way.
The size of the decompressor is usually around a few hundred bytes,
depending on the complexity of the compression method. This
constitutes an unavoidable overhead in the compressed file, which is
particularly evident for small files, such as 4k intros. Furthermore,
the header of the Windows EXE file format contains a lot of
information that needs to be there at fixed offsets in order for
Windows to be able to load the file. The presence of these overheads
from the header and decompressor motivated people to look for other
means of compressing their 4k intros.
Until Crinkler came around, the most popular strategy for compressing
4k intros for Windows was CAB dropping: A few simple transformations
are performed on the executable to make it compress better (such as
merging sections and setting unused header fields to zero), and the
result is compressed using the Cabinet Compression tool included with
Windows. The resulting .CAB file is renamed to have .BAT extension,
and some commands are inserted into the file such that when the .BAT
file is executed, it decompresses the executable to disk (using the
Cabinet decompression command), runs the executable and then deletes
the executable again. This saves the size of the decompression code
(since an external program is used to do the decompression) and some
of the size of the header (since the header can be compressed).
Various dropping strategies combined with other space-saving hacks
people have employed on their 4k intros (in particular import by
ordinal) have caused severe compatibility problems. More often than
not, people who want to run a newly released 4k intro find that it
does not work on their own machine. In recent years, it has been
customary to include a 'compatible' version in the distribution which
is larger than 4k but works on all machines. The term '4k intro' seems
to mean '4k on the compo machine' intro.
The main motivation for starting the Crinkler project was the feeling
that the existing means available for compressing 4k intros were
unsatisfactory. We want 4k intros that are self-contained EXE
files. We want 4k intros that are 4 kilobytes in size. Our aim for
Crinkler is to be the cleanest, most effective and most compatible
executable file compressor for Windows 4k intros.
INTRODUCTION
------------
Crinkler is a different approach to executable file compression. While
an ordinary executable file compressor operates on the executable file
produced by the linker from object files, Crinkler replaces the linker
by a combined linker and compressor. The result is an EXE file which
does not do any kind of dropping. It decompresses into memory like a
traditional executable file compressor.
Crinkler employs a range of techniques to reduce the size of the
resulting EXE file beyond what is usually obtained by using CAB
compression:
- Having control over the linking step gives much more flexibility in
the optimizations and transformations possible on the data before
and after compression.
- The compression technique used by Crinkler is based on context
modelling, which is far superior in compression ratio to the LZ
variants used by CAB and most other compressors. The disadvantage of
context modelling is that it is extremely slow, but this is of
little importance when only 4 kilobytes need to be compressed. It
also needs quite a lot of memory for decompression, but this is
again not a problem, since the typical 4k intro uses a lot of memory
anyway.
- The actual compression algorithm performs many passes over the data
in order to optimize the internal parameters of the compressor. This
results in slower compression, but this is usually a reasonable
price to pay for the extra bytes gained on the file size.
- The contents of the executable are split into two parts - a code
part and a data part - and each of these are compressed
individually. This leads to better compression, as code and data are
usually very different in structure and so do not benefit from being
compressed together.
- DLL functions are imported by hash code. This is robust to
structural changes to the DLL between different versions while being
quite compact - only 4 bytes per imported function. For DLLs with
fixed relative ordinals (such as opengl32), a special technique,
ordinal range import, can be used to further reduce the number of
hash codes needed.
- Much of the data in the EXE header is actually ignored by the EXE
loader. Some of this space is used for some of the decompression
code, and the rest is used to store hash codes for imported
functions.
Using Crinkler is somewhat different from using an ordinary executable
file compressor because of the linking step. In the following
sections, we describe its use in detail.
INSTALLATION
------------
To use as a stand-alone linker, Crinkler does not need any
installation. Simply run crinkler.exe from the commandline with
appropriate arguments, as described in the next section.
However, if you are using Microsoft Visual Studio to develop your
intro, the easiest way to use Crinkler is to run it in place of the
normal Visual Studio linker. Crinkler has been designed as a drop-in
replacement of the Visual Studio linker, supporting the same basic
options. All of the options can then be set using the Visual Studio
configuration window.
Unfortunately, Visual Studio does not (as of this writing) support
replacing its linker by a different one. So what you have to do is the
following:
- Copy crinkler.exe to your project directory and rename it to
link.exe. Visual Studio will then find it when it tries to invoke
the linker. If you are using some other linker with a different
name, such as the one used with the Intel C++ compiler, call it
whatever the name of the linker is.
- Select Tools/Options... and go to Projects and Solutions/VC++
Directories. At the top of the list for Executable files, add
$(SolutionDir). This will make sure that the project directory is
searched for the linker executable.
- In the Release configuration (or whichever configuration you want to
enable compression), under Linker/Command Line/Additional Options,
type in /CRINKLER, along with any other Crinkler options you want to
set. See the next section for more details on options. Also set
Linker/Manifest File/Generate Manifest to No and
C/C++/Optimization/Whole Program Optimization to No.
If you have Visual Studio installed but want to run Crinkler from the
commandline, the easiest way is to use the Visual Studio Command
Prompt (available from the Start menu), since this sets up the LIB
environment variable correctly. You can read off the value of the
environment variables by running the 'set' command in this command
prompt. If you are using a different command prompt, you will have to
set up the LIB environment variable manually, or use the /LIBPATH
option.
USAGE
-----
The general form of the command line for Crinkler is:
CRINKLER [options] [object files] [library files] [@commandfile]
When running from within Visual Studio, the object files will be the
ones generated from the sources in the project. The library files will
be the standard set of Win32 libraries, plus any additional library
files specified under Linker/Input/Additional Dependencies. If you are
using a standard runtime library, such as libc or msvcrt, you will
have to specify this one manually.
The following options are compatible with the VS linker and can be set
using switches in the Visual Studio configuration window:
/SUBSYSTEM:CONSOLE
/SUBSYSTEM:WINDOWS
(Linker/System/SubSystem)
Specify the Windows subsystem to use. If the subsystem is CONSOLE,
a console window will be opened when the program starts. The
subsystem also determines the name of the default entry point (see
/ENTRY). The default subsystem is WINDOWS.
/OUT:[file]
(Linker/General/Output File)
Specify the name of the resulting executable file. The default
name is out.exe.
/ENTRY:[symbol]
(Linker/Advanced/Entry Point)
Specify the entry label in the code. The default entry label is
mainCRTStartup for CONSOLE subsystem applications and
WinMainCRTStartup for WINDOWS subsystem applications.
/LIBPATH:[path]
(Linker/General/Additional Library Directories)
Add a number of directories (separated by semicolons) to the ones
searched for library files. If a library is not found in any of
these, the directories mentioned in the LIB environment variable
are searched.
@commandfile
Commandline arguments will be read from the given file, as if they
were given directly on the commandline.
In addition to the above options, a number of options can be given to
control the compression process. These can be specified under
Linker/Command Line/Additional Options:
/CRINKLER
Enable the Crinkler compressor. If this option is disabled,
Crinkler will search through the path for a command with the same
name as itself, skipping itself, and pass all arguments on to this
command instead. This will normally invoke the Visual Studio
linker. If the name of the Crinkler executable is crinkler.exe,
this option is enabled by default, otherwise it is disabled by
default.
/FIX
Fix a program compressed using an older version of Crinkler so
that it works on all versions of Windows 2000, XP and Vista and is
compatible with Data Execution Prevention. When this option is
specified, all other options except /OUT are ignored, and Crinkler
takes a single file argument, which must be an output EXE file
from Crinkler 0.3 or newer.
/PRIORITY:IDLE
/PRIORITY:BELOWNORMAL
/PRIORITY:NORMAL
Select the process priority at which Crinkler will run while
compressing. The default priority is BELOWNORMAL. Use IDLE if you
want Crinkler to disturb you as little as possible. Use NORMAL if
you don't need your machine for anything else while compressing.
/COMPMODE:INSTANT
/COMPMODE:FAST
/COMPMODE:SLOW
Choose between three different compression modes. The FAST mode
usually compresses in a couple of seconds, while the SLOW one can
take up to a few minutes to complete. The slow one usually
compresses about 10-40 bytes better on a 4k executable. Use
INSTANT if you just want to check that your program works in
compressed form and don't care about the size. The default
compression mode is FAST.
/HASHSIZE:[memory size]
Specify the amount of memory the decompressor is allowed to use
while decompressing, in megabytes. In general, the more memory the
decompressor is allowed to use, the better the compression ratio
will be, though only slightly. The memory requirements of the
final executable (the size of the executable image when loaded
into memory) will be the maximum of this value and the original
image size. The memory will not be deallocated until the program
terminates, and any heap allocation the program performs will add
to this memory usage. The default value is 100, which is usually a
good compromise.
/HASHTRIES:[number of retries]
Specify the number of different hash table sizes the compressor
will try in order to find one with few collisions. More tries lead
to longer compression time but slightly better compression. The
default value is 20. Higher values rarely improve the size by more
than a few bytes.
/ORDERTRIES:[number of retries]
Specify the number of section reordering iterations that the
linker will try out in search for the ordering that gives the best
compression ratio. The default is not to do any reordering.
Specifying this option drastically increases the compression time,
since Crinkler has to calculate the compressed size anew on every
reordering. Usually, the size does not improve noticeably after a
few thousand iterations.
/RANGE:[DLL name]
Import functions from the given DLL (without the .dll suffix)
using ordinal range import. Ordinal range import imports the first
used function by hash and the rest by ordinal relative to the
first one. Ordinal range import is safe to use on DLLs in which
the ordinals are fixed relative to each other, such as opengl32 or
d3dx9_??. This option can be specified multiple times, for
different DLLs.
/REPLACEDLL:[oldDLL=newDLL]
Whenever a function is imported from oldDLL, import it from newDLL
instead. DLL replacement is useful when the end user might not
have the version of the DLL that you are linking to. A typical use
is to replace one version of d3dx9_?? by another. Only use this
option if you know that the two DLLs are compatible. When
REPLACEDLL and RANGE are used together, RANGE must refer to the
new DLL.
/UNSAFEIMPORT
If the executable fails to load some DLL, it will normally pop up
a message box with the DLL name. This option disables this check
to save a few bytes (usually around 20). With unsafe import, the
executable will crash if a needed DLL is not found.
/TRANSFORM:CALLS
Change the relative jump offsets in all internal call instructions
(E8 opcode) into absolute offsets from the start of the code. This
usually improves compression, since multiple calls to the same
function become identical. The transformation has an overhead of
about 20 bytes for the detransformation code, but the net savings
on a full 4k can be as large as 50 bytes, depending on the number
of calls in your code.
/TRUNCATEFLOATS:[number of bits]
Floating point constants can take up a significant amount of space
in an intro, and often much of this space is wasted because the
constants have more precision than needed. Typically, many bytes
can be saved by rounding floating point constants to "nice" values
- that is, values where many bits in the mantissa are zero.
However, such rounding is cumbersome, especially when the
constants are written in decimal notation.
The purpose of the /TRUNCATEFLOATS option is to automate this
rounding process. When this option is given, Crinkler tries to
identify float and double constants and round them to the number
of bits given (between 1 and 64). If no number is given, 32 is
assumed.
Typically, object files do not contain any information about what
data is floating point constants and what is not (though the file
format does support such information). This means that in order to
identify floating point constants, Crinkler has to resort to
heuristics based on label names. These heuristics are able to
recognize constants in code and some variables, but far from all.
You can tell Crinkler explicitly that some variable contains float
data and how much it should be truncated by having the variable
name (or label) start with tf[n]_ where [n] is the number of bits
to truncate the constants to. The number of bits can be omitted,
in which case the number of bits given in the argument to
/TRUNCATEFLOATS is used. Such variables will still only be
truncated if the /TRUNCATEFLOATS option is given. Example:
const float tf14_positions[] = { 0.1f, 0.35f, 0.25f };
This will truncate the constants in the table to 14 bits (5 bits
of mantissa), resulting in the values 0.099609375, 0.3515625 and
0.25, respectively. Tip: rather than changing the variable name
and all references to it each time you want to change the
truncation precision, use a define:
#define positions tf14_positions
Note that /TRUNCATEFLOATS is an unstable and highly experimental
feature. Make sure to test the compressed file to verify that the
result is acceptable. Remember to include the musician in this
verification process. :)
Finally, Crinkler has a number of options for controlling the output
during compression. Just like the other options, these can be
specified under Linker/Command Line/Additional Options:
/REPORT:[HTML file name]
Write an HTML file with a detailed, colorful, interactive report
on the compression result. The code section will be shown as hex
dump and disassembly of the code, and the data section will be
shown as hex and ascii dump. All bytes will be colored to show how
much that byte was compressed. This report can be useful in
determining which parts of the executable take up the most space
and which things to change to reduce the size.
/PRINT:LABELS
Print a list of all labels in the program along with uncompressed
and compressed sizes for the data between the labels. This is a
stripped down version of the information provided by the /REPORT
option.
/PRINT:IMPORTS
List all functions imported from DLLs. The functions are grouped
by DLL, and functions imported by ordinal range import are grouped
into ranges.
/PRINT:MODELS
List the model masks and weights selected by the compressor. This
is mostly for internal use.
/PROGRESSGUI
Open a window showing a graphical progress indicator.
An example commandline for linking and compressing an intro could look
like this (split on multiple lines for readability):
crinkler.exe /OUT:micropolis.exe /SUBSYSTEM:WINDOWS /RANGE:opengl32
/COMPMODE:SLOW /ORDERTRIES:1000 /PRINT:IMPORTS /PRINT:LABELS
kernel32.lib user32.lib gdi32.lib opengl32.lib glu32.lib winmm.lib
micropolis\startup.obj micropolis\render.obj
micropolis\render-asm.obj micropolis\sound.obj
micropolis\sound-asm.obj
STANDARD RUNTIME LIBRARIES
--------------------------
Under normal circumstances, the Visual Studio compiler generates code
that requires a C runtime library containing standard C functions and
various support functions. These functions can either be linked in
statically (included into the executable) or dynamically via a runtime
DLL. For size-sensitive applications, you should always link
dynamically, which is achieved by setting C/C++/Code
Generation/Runtime Library to Multi-threaded DLL (/MD).
Note however, that the standard runtime libraries for Visual Studio
2005 or newer will not work with Crinkler-compressed executables,
since these runtime libraries require a manifest in the executable,
and Crinkler does not support manifests. Furthermore, these DLLs are
not present by default on Windows installations, so you will usually
not want your program to be dependent on them.
To work around this, link to the Visual Studio 6 runtime library -
msvcrt.dll - which is distributed with all Windows versions. This is
done by using the Visual Studio 6 version of msvcrt.lib, which can be
obtained thus:
- Download Service Pack 6 for Visual Studio 6.0 at
http://msdn.microsoft.com/en-us/vstudio/aa718364.aspx
- Place the downloaded self-extractor in an empty directory and run
it, or open it using an archive tool such as WinRAR.
- Open the VS6sp61.cab file and go to the vc98\lib directory. There
you will find the msvcrt.lib file.
- Rename this file to something else (such as msvcrt_old.lib) and
place it in your project directory.
- Add msvcrt_old.lib to the list of libraries to link to at
Linker/Input/Additional Dependencies.
There are a couple of caveats to using an older runtime library than
the comnpiler expects, though. With out-of-the-box compilation
options, the Visual Studio compiler generates code that requires some
support functions which are only present in newer runtime DLLs. To
avoid these dependencies, set the following options under C/C++/Code
Generation:
- Basic Runtime Checks: Default
- Buffer Security Check: No (/GS-)
Also, do not use C++ exception handling in your code.
Finally, even when using the DLL-based runtime, not all support code
is linked dynamically. The runtime library contains an entry function
which is included into the executable and takes care of things like
parsing the commandline and executing static initializers. The entry
function then calls the main function.
The standard entry function is around half a kilobyte in size and is
usually not needed for intro code to function properly. To avoid this
overhead, define your own entry function, either by defining a
function called mainCRTStartup or WinMainCRTStartup (depending on
which Windows subsystem you use) or by using the /ENTRY option.
The best strategy is of course to avoid linking to a runtime DLL at
all, assuming you can do without the functions provided by the
standard runtime library. This will save the space for importing the
runtime DLL.
To reduce the dependencies on the standard runtime DLL as much as
possible, set the following options:
- C/C++/Optimization/Enable Intrinsic Functions: Yes (/Oi). This will
cause several standard functions (mainly math, string and memory
functions) to generate inline code rather than a function call.
- C/C++/Code Generation/Floating Point Model: Fast (/fp:fast).
- C/C++/Command Line: Add the option /QIfist. This will cause
conversions from floating point to integer to use the FIST
instruction rather than calling a conversion function. Note that
this changes the semantics of conversions from truncation to
round-to-nearest (unless you explicitly change the rounding mode of
the FPU). On the other hand, it will also give a considerable speed
boost.
RECOMMENDATIONS
---------------
There are a number of things you can do as intro programmer to boost
the compression achieved by Crinkler even further. This section
gives some advice on these.
- Since much of the effectiveness of Crinkler comes from separating
code and data into different parts of the file and compressing each
part individually, it is important that this separation is
possible. Mark your code and data sections as containing code and
data, respectively, and do not put both code and data into the same
section. See your assembler manual for information about how to do
this. For instance, in Nasm, you can write the keyword "text" or
"data" after the section name and give sections different names to
prevent them from being merged by the assembler.
- Split both your code and your data into as many sections as
possible. This gives Crinkler more opportunities to select the
ordering of the sections to optimize the compression ratio.
- If you are using OpenGL, use ordinal range import for opengl32. If
you are using Direct3D, use ordinal range import for d3dx9_??. This
drastically reduces the space needed for function hash codes.
- Avoid large blocks of data, even if they are all zero. Use
uninitialized (bss) sections instead. Crinkler does not cope well
with large amounts of data. Be aware that the compressor may use an
amount of memory up to about 4000 times the uncompressed code/data
size (whichever is largest).
- When you perform detailed size comparisons, always use the SLOW
compression mode with plenty of HASHTRIES and ORDERTRIES. The
INSTANT and FAST modes are only intended for use during testing and
to give a rough estimate of the compressed size. Also note that the
compression is tuned for the 4k size target, so any size comparisons
you perform on smaller files might turn out to behave differently
when you get nearer to 4k.
- As a matter of good conduct, do not use UNSAFEIMPORT if you can
spare the space, and do not set HASHSIZE higher than you need. In
other words, if your final intro is well below the size limit,
remove the UNSAFEIMPORT option (if you added it in the first place)
and then lower HASHSIZE in order not to waste memory unnecessarily.
COMMON PROBLEMS, KNOWN BUGS AND LIMITATIONS
-------------------------------------------
Any DLL that is needed by a program that Crinkler compresses must be
available to Crinkler itself. If you get the error message 'Could not
open DLL ...', it means that Crinkler needed the DLL but could not
find it. You must place it either in the same directory as the
Crinkler executable or somewhere in the DLL path, such as
C:\WINDOWS\system32. Alternatively, you can use the REPLACEDLL option
to replace it by one that is available.
If you launch your Crinkler-compressed program from within Visual
Studio, use Start Without Debugging (Ctrl+F5) rather than Start
Debugging (F5). The debugger cannot handle Crinkler-compressed
executables. If the program crashes, you can still attach the debugger
in the normal way.
When running inside Visual Studio, the textual progress bars are not
updated correctly, since the Visual Studio console does not flush the
output until a newline is reached, even when explicitly flushed by the
running program. Use the /PROGRESSGUI option to get a graphical
progress bar.
The code for parsing object and library files contains only a minimum
of sanity checks. If you pass a corrupt file to Crinkler, it will most
likely crash.
The import code does not support forwarded RVA imports, which means
that some functions, such as HeapAlloc, cannot be used. This makes
Crinkler unable to link with libc. What a loss.
The final compressed size must be less than 64k, or Crinkler will fail
horribly. You shouldn't use it for such big files anyway.
SUPPORT
-------
Try out Crinkler, and let us know what you think about it. If you have
any problems, comments or suggestions, please write a message at the
Pouet.net forum:
http://www.pouet.net/prod.php?which=18158
If you want to contact us directly, e.g. for sending us a file, write
to authors@crinkler.net.
The newest released version of Crinkler can always be found at
http://www.crinkler.net.
ACKNOWLEDGEMENTS
----------------
The compression technique used by Crinkler is much inspired by the PAQ
compressor by Matt Mahoney.
The import code is loosely based on the hashed imports code by Peci.
Many thanks to all the people who have given us comments, bug reports
and test material, especially to Rambo, Kusma, Polaris, Gargaj,
Frenetic, Buzzie, Shash, Auld, Minas, Skarab, Dwing, Freak5, Hunta,
Snq, Darkblade, Abductee, iq, Las, pirx and Hitchhikr. Also thanks to
Dwarf, Polygon7 and Gargaj for suggestions for our web design.
Our special thanks to the many people who have demostrated the
usefulness of Crinkler by using it for their own productions.
Keep it going! We greatly appreciate your feedback.