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Readme.md

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