This file is intended to be a short guide for getting AS compiled on
a Unix-like operating system.  If you are interested in a more in-depth
discussion of the source code of AS, take a look in the appropriate chapter
of the AS user's manual (german resp. english version located in the doc_DE/
resp. doc_EN/ subdirectory).  I highly recommend reading this chapter before
you make extensions or modifications to the source code.

The installation process consists of the following steps:

(1) see if there are additional README files for your platform
(2) create a Makefile.def
(3) compile
(4) execute the test suite
(5) build the documentation
(6) install into the system directories

Step (1): 

On some (especially non-Unix) platforms, some additional preliminaries 
are needed: 

--> If you do not have a C compiler conforming to the ANSI standard,
    take a look into 'README.KR'.

--> For MS-DOS and OS/2 platforms, additionally read README.DOS resp.
    README.OS2

Step (2):

Settings that may vary from platform to platform are located in a file
called 'Makefile.def'.  Your task is either to select an approriate file
from the 'Makefile.def-samples' directory, or to create an own one.  I know
this is a bit tedious process, and one day I will probably replace this
scheme with an autoconf-style configuration, but for now we will have to
live with it.  A good starting point for a gcc-based, 'normal' Unix system
is the file 'Makefile.def.tmpl'.  The settings to make include:

- A couple of helper tools are created during the build process.  To build
  them, the following variables must be set:

  - CC: The C compiler used to compile sources into objects
  - CFLAGS: Any additional flags to be passed to the compiler.  This may
    include optimization level or warning/error verbosity.
  - OBJDIR: If you like having objects and executables in a separate
    directory, specify it via this variable.  A trailing slash is required,
    e.g. you have to write 'obj/' instead of 'obj'.
  - HOST_OBJEXTENSION: the file extension used for object files.  On a
    Unix-like system, this is typically '.o', but non-Unix systems may use
    other extensions like '.obj'.
  - LD: The linker used to create executables form objects.  On a Unix
    system, this is the same as $(CC).
  - LDFLAGS: Any libraries or flags possibly needed for the linker.
  - HOST_EXEXTENSION: the file extension used for executables.  On a Unix
    system, this variable is typically left empty.  Other systems may
    require a settling like '.exe'.

- There is another set of these variables: TARG_OBJDIR, TARG_CC, TARG_CFLAGS,
  TARG_OBJEXTENSION, TARG_LD, TARG_LDFLAGS, TARG_EXEXTENSION.  They are used
  to build the actual assembler and tool binaries.  The distinction is needed
  because cross-builds are supported, i.e. you are on system X and want to
  build binaries for system Y.  In case you do not want to cross-build, you
  may set them to the same values as the 'host-related' variables.  The file
  Makefile.def.tmpl demonstrates how to do this.

- There is another variable TARG_RUNCMD.  If you are cross-building and there
  is a way to run the built binaries on the host system (like an emulator),
  define it here as a command prefix.  For instance, if you have built Windows
  binaries on a Linux system, set TARG_RUNCMD to 'wine' and you will be able
  to run the 'make test' target.

- INSTROOT: directory subtree where AS should be   placed after compilation.
  (binaries in $INSTROOT/bin, includes in $INSTROOT/include, and so on).

- TEX2DOC_FLAGS: in case you are cross-building, you may want to generate
  the plaintext version of the manual in a character set appropriate for the
  target system.  You may a '-codepage xxx' option in this variable to override
  the character set detected on the host system.  xxx may be one of ascii,
  iso8859-1, iso8859-15, koi8-r, 437, 850, 866, 1251, 1252, or utf-8.

Step (3):

Compilation should be a simple matter of saying 'make' and waiting...
depending on your machine, compliation time can be between a few minutes
(a modern Pentium-based PC or a fast Alpha) and a day (VAXstation 2000).
A few compilers (like newer egcs releases or Borland-C) are known to
generate a lot of warnings about ambigious statements or unused parameters.
I will try to eliminate them when time permits, but I have no high priority
for doing this since they are harmless.

If you are compiling AS for a new platform, you will probably run into
an error message saying that you have to edit 'sysdefs.h'.  This file
collects information about the anomalies and specialities of certain
systems.  The include file detects a system by querying macros the compiler
predefines and makes the appropriate definitions.  The file is sorted by

1. processor architecture
  2. manufacturer
    3. operating system

Find out the preprocessor symbols your compiler defines, make a new section
in 'sysdefs.h' and send it to me so I can include it in the next release of
AS!

Step (4):

Type 'make test' and the freshly compiled AS will be run on a couple of
test programs.  For each program, the output is compared to a reference
binary included in the distribution.  The binary output has to match
*exactly*, i.e. there must not be any difference.  Any failed test reported
by the script has to be investigated, even if it happens for a target
platform you never intend to use!

Step (5):

The documentation of AS is distributed in LaTeX format.  I chose this format
because TeX is available on about any platform suitable for AS I can think
of.  Other formats are created by typing 'make docs': simple ASCII, HTML,
and Postscript. You need a TeX distribution including dvips for the latter,
while converters to ASCII and HTML are included.

Step (6):

Type 'make install'.  Depending on the target directories you chose in Step
(1), you may have to acquire root privileges to install AS.

Have fun!

Alfred Arnold, alfred@ccac.rwth-aachen.de
