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+
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+-----------------------------
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+Original readme:
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+
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+ dcc Distribution
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+
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+The code provided in this distribution is (C) by their authors:
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+ Cristina Cifuentes (most of dcc code)
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+ Mike van Emmerik (signatures and prototype code)
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+ Jeff Ledermann (some disassembly code)
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+and is provided "as is".
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+
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+The following files are included in the dccoo.tar.gz distribution:
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+- dcc.zip (dcc.exe DOS program, 1995)
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+- dccsrc.zip (source code *.c, *.h for dcc, 1993-1994)
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+- dcc32.zip (dcc_oo.exe 32 bit console (Win95/Win-NT) program, 1997)
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+- dccsrcoo.zip (source code *.cpp, *.h for "oo" dcc, 1993-1997)
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+- dccbsig.zip (library signatures for Borland C compilers, 1994)
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+- dccmsig.zip (library signatures for Microsoft C compilers, 1994)
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+- dcctpsig.zip (library signatures for Turbo Pascal compilers, 1994)
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+- dcclibs.dat (prototype file for C headers, 1994)
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+- test.zip (sample test files: *.c *.exe *.b, 1993-1996)
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+- makedsig.zip (creates a .sig file from a .lib C file, 1994)
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+- makedstp.zip (creates a .sig file from a Pascal library file, 1994)
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+- readsig.zip (reads signatures in a .sig file, 1994)
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+- dispsrch.zip (displays the name of a function given a signature, 1994)
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+- parsehdr.zip (generates a prototype file (dcclibs.dat) from C *.h files, 1994)
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+
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+Note that the dcc_oo.exe program (in dcc32.zip) is a 32 bit program,
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+so it won't work under Windows 3.1. Also, it is a console mode program,
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+meaning that it has to be run in the "Command Prompt" window (sometimes
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+known as the "Dos Box"). It is not a GUI program.
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+
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+The following files are included in the test.zip file: fibo,
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+benchsho, benchlng, benchfn, benchmul, byteops, intops, longops,
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+max, testlong, matrixmu, strlen, dhamp.
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+The version of dcc included in this distribution (dccsrcoo.zip and
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+dcc32.exe) is a bit better than the first release, but it is still
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+broken in some cases, and we do not have the time to work in this
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+project at present so we cannot provide any changes.
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+Comments on individual files:
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+- fibo (fibonacci): the small model (fibos.exe) decompiles correctly,
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+ the large model (fibol.exe) expects an extra argument for scanf().
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+ This argument is the segment and is not displayed.
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+- benchsho: the first scanf() takes loc0 as an argument. This is
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+ part of a long variable, but dcc does not have any clue at that
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+ stage that the stack offset pushed on the stack is to be used
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+ as a long variable rather than an integer variable.
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+- benchlng: as part of the main() code, LO(loc1) | HI(loc1) should
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+ be displayed instead of loc3 | loc9. These two integer variables
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+ are equivalent to the one long loc1 variable.
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+- benchfn: see benchsho.
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+- benchmul: see benchsho.
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+- byteops: decompiles correctly.
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+- intops: the du analysis for DIV and MOD is broken. dcc currently
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+ generates code for a long and an integer temporary register that
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+ were used as part of the analysis.
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+- longops: decompiles correctly.
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+- max: decompiles correctly.
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+- testlong: this example decompiles correctly given the algorithms
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+ implemented in dcc. However, it shows that when long variables
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+ are defined and used as integers (or long) without giving dcc
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+ any hint that this is happening, the variable will be treated as
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+ two integer variables. This is due to the fact that the assembly
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+ code is in terms of integer registers, and long registers are not
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+ available in 80286, so a long variable is equivalent to two integer
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+ registers. dcc only knows of this through idioms such as add two
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+ long variables.
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+- matrixmu: decompiles correctly. Shows that arrays are not supported
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+ in dcc.
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+- strlen: decompiles correctly. Shows that pointers are partially
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+ supported by dcc.
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+- dhamp: this program has far more data types than what dcc recognizes
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+ at present.
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+
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+Our thanks to Gary Shaffstall for some debugging work. Current bugs
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+are:
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+- if the code generated in the one line is too long, the (static)
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+ buffer used for that line is clobbered. Solution: make the buffer
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+ larger (currently 200 chars).
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+- the large memory model problem & scanf()
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+- dcc's error message shows a p option available which doesn't
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+ exist, and doesn't show an i option which exists.
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+- there is a nasty problem whereby some arrays can get reallocated to
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+ a new address, and some pointers can become invalid. This mainly
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+ tends to happen to larger executable files. A major rewrite will
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+ probably be required to fix this.
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+
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+For more information refer to the thesis "Reverse Compilation
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+Techniques" by Cristina Cifuentes, Queensland University of
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+Technology, 1994, and the dcc home page:
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+ http://www.it.uq.edu.au/groups/csm/dcc_readme.html
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+
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+Please note that the executable version of dcc provided in this
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+distribution does not necessarily match the source code provided,
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+some changes were done without us keeping track of every change.
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+
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+Using dcc
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+
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+Here is a very brief summary of switches for dcc:
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+
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+ a1, a2: assembler output, before and after re-ordering of input code
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+ c: Attempt to follow control through indirect call instructions
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+ i: Enter interactive disassembler
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+ m: Memory map
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+ s: Statistics summary
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+ v, V: verbose (and Very verbose)
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+ o filename: Use filename as assembler output file
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+
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+If dcc encounters illegal instructions, it will attempt to enter the so called
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+interactive disassembler. The idea of this was to allow commands to fix the
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+problem so that dcc could continue, but no such changes are implemented
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+as yet. (Note: the Unix versions do not have the interactive disassembler). If
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+you get into this, you can get out of it by pressing ^X (control-X). Once dcc
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+has entered the interactive disassembler, however, there is little chance that
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+it will recover and produce useful output.
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+
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+If dcc loads the signature file dccxxx.sig, this means that it has not
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+recognised the compiler library used. You can place the signatures in a
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+different direcory to where you are working if you set the DCC environment
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+variable to point to their path. Note that if dcc can't find its signature files, it
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+will be severely handicapped.
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