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Littlle Smalltalk Installation Notes _2. _S_p_e_c_i_f_i_c _M_a_c_h_i_n_e _I_n_s_t_a_l_l_a_t_i_o_n _I_n_s_t_r_u_c_t_i_o_n_s A single source form and command syntax cannot be used for all combinations of machine / operating systems, because of differences in library routine syntax or function availa- bility. An attempt has been made to surround the occurrences of such features with conditional compilation directives, so that by defining or not defining a symbol the correct result can be produced on different systems. These commands have all been collected in the include file parser/env.h, so for the most part this should be the prin- ciple file needing to be edited. In addition, ``meta- defines'' are provided for many systems to which the Little Smalltalk system has already been ported. By defining one of these ``meta-defines'', correct values are given for the remainder of the symbols. There are a few places where path specifications must be given in the C sources. These are described in the following sections. Finally, bytecodes are kept in the form of ``unsigned characters''; that is, characters containing numbers from 0-255. These may or may not be supported on various machines. The file parser/env.h contains a typedef for the type `uchar' and two macros for converting from unsigned characters to integers and back again. These should be defined in such a manner that the appearance of unsigned characters is achieved, whether or not they are actually supported. Generally, either the model of the VAX-780 or the PDP11/70 should be sufficient. _2._1. _B_r_i_n_g_i_n_g _L_i_t_t_l_e _S_m_a_l_l_t_a_l_k _U_p _o_n _a _N_e_w _S_y_s_t_e_m If the system you are attempting to port to is not one of the systems described in the following sections, a cer- tain amount of experimentation will probably be necessary to successfully install the system. This section will describe some of the major changes required; what other changes may be necessary is generally unpredictable. The file parser/env.h contains various hard paths, which are described in that file. Also in that file, the following symbols should be defined or left undefined, depending upon the availability of various features. CURSES This symbol should be defined if it is desired to provide the simple ascii graphics given by the curses and termcap packages. See section on graphics below. ENVSAVE This symbol should be defined if it is necessary to save the value of the global varible _e_n_v_i_r_o_n during a fastload. This is necessary on the 11/70, IBM PC, possibly other machines. FACTMAX This symbol should be defined to be the largest integer for which the factorial can be computed by repeated multiplication without overflow. This value is generally 12 for 32 bit machines and 8 for 16 bit machines. FASTDEFAULT This symbol should be defined if the default behavior of the system should be to perform a fast load on the standard prelude (see section 3). FLUSHREQ If defined a fflush() is given after every call to printf. GAMMA This symbol should be defined if the gamma() func- tion is part of the standard math library, left undefined otherwise. INLINE This symbol should be defined if in-line code is desired for object increments and decrements. In line code is generally slightly faster, although the code size is slightly larger. If this symbol is not defined subroutine calls will be generated for object increments and decrements. NOSYSTEM This symbol should be defined on non-unix systems for which the ``system()'' call is not supported. As this seriously limits functionality (i.e. class descriptions cannot be modified during execution) is should not be used unless necessary. OPEN3ARG This symbol should be defined if Berkeley 4.2 style open statements (3 arguments) are used. If the older, 2 argument, format is used this symbol should be left undefined. PLOT3 This symbol should be defined if you have termi- nals for which the plot(3) routines can write directly to the screen, rather than requiring a postprocessing filter. See section on graphics below. SETJUMP This symbol should be defined if the setjump/longjump facility is available. This is used ONLY in the file sources/process.c to imple- ment recovery when the user has typed an interrupt character. SHORTDATA If this symbol is defined various heuristics are used to reduce the data segment size, at the expense of functionality or execution speed. Should only be defined if absolutely necessary. SIGS This symbol should be defined if the signals facility is available. This is used ONLY in the file sources/process.c to implement recovery when the user has typed an interrupt character. _2._2. _B_e_r_k_e_l_e_y _l_o_o_k_a_l_i_k_e_s It has been reported that following the directions for Berkeley 4.2 (below) is also sufficient for the following systems: Amdahl / System V Pyramid 90x / System V Sequent Balance 8000 _2._1_1. _V_A_X _7_8_0 / _B_e_r_k_e_l_e_y _4._2 In parser/env.h the ``meta-define'' BERK42 should be given, and any other meta-defines removed. Also in env.h the paths in the strings TEMPFILE, PARSER and PRELUDE should be defined. (VAX only) If the -g flag is used the define FLUSHREQ need not be given (although it will work if it is present), otherwise FLUSHREQ should be defined in order for input and output to interleave correctly. As distributed, the system does not perform a fastload (see next section) automatically. If fastload works this can be made default by defining the symbol FASTDEFAULT. These instructions appear to work also for the SUN workstation; of course, if you have a SUN workstation you can run the Xerox system. _3. _F_a_s_t _L_o_a_d_i_n_g The Little Smalltalk system has the ability to save and restore a user environment by basically moving a copy of all of the users data space into a file. Although this produces rather large files, the savings in time permitted by not having to recreate a specific environment can be substan- tial. Because this is such an unusual thing to do, it is probably wise, if installing the system on a new machine/operating system, to first comment out the define for FASTDEFAULT in parser/env.h, which will install a system which will not default to doing a fast load. Once such a system has been created and passed all self tests, you can experiment with fast loading by executing the st command with the argument -f. For test cases you can use the programs in /tests. If it appears to be successful, then (by defining the variable FASTDEFAULT) you should regenerate the system so that the default behavior is to do a fast loading. (When regenerating the system, sources/main.c should be the only file needing to be recom- piled). Fastloading does not currently work on the HP-9000. It may not work on other machines as well. _4. _P_r_o_t_e_c_t_i_o_n_s The directories /sources and /parser need not be read- able by casual users. The directory /prelude contains files, however, which must be loaded by the Little Smalltalk system prior to every execution. The protection of this directory, and on the files in it, should therefore be such that all users have READ access. Although the /tests directory is only used during system installation, users may want to refer to it for examples of class descriptions and to see how various problems (8 queens, dinning philosophers) have been solved in Smalltalk. Allowing all users access to the /docs directory will permit a kind of on-line access, however users should not be allowed to modify any files in any directory. _5. _N_o_n-_U_N_I_X _s_y_s_t_e_m_s Non-UNIX* systems which do not support multiple user processes, and thus the system() call, cannot at current run Little Smalltalk. There are plans, however, to at some time in the future support such systems. This section will describe, in broad terms, the changes required. The detailed changed are, of course, at the moment not known. First, the defined value NOSYSTEM must be given in parser/env.h. This will cause all occurrences of the ``sys- tem()'' call to be commented out, and in most cases be replaced by error messages. Next, the parser must be modified to place its output in a file (presumably the file given as argument with .st replaced by .p) instead of the standard output. This is a trivial, although probably system specific, change. In use, the user would then be required to ``compile'' all class descriptions by running the parser (which there- fore would have to be user accessible program) before run- ning the Little Smalltalk system. Little Smalltalk could not be used to edit class descriptions on the fly - the user would have to leave the system, perform the edit, and return to the system. This would seriously limit functionality and utility, but that is cost of not running UNIX! _6. _G_r_a_p_h_i_c_s The nice bit-mapped graphics display of the Smalltalk- 80 system is, unfortunately, not very portable to conven- tional machines running conventional ascii terminals. Two mutually exclusive approaches have been furnished for pro- viding vvvveeeerrrryyyy rudimentary but nevertheless relatively device- independent graphics capabilities. The first approach used the curses(3) and termlib(3) routines to provide simple ascii (character-level) graphics. To use these, define the symbol CURSES in parser/env.h, and modify the Makefile in /sourses adding the libraries -lcurses and -ltermlib (or termcap, whichever is appropri- ate) to the symbol LIB. _________________________ * UNIX is a trademark of AT&T Bell Laboratories. The functionality so provided can be described as fol- lows: clearScreenThis message is accepted by the pseudo-variable smalltalk and clears the screen. printAt: This message is accepted by instances of class String. The argument must be a point, represent- ing a line@column pair. The string is printed at the point. In addition, there is a class FFFFoooorrrrmmmm found in /prelude, which is an attempt at providing simple graphics forms. Instances of FFFFoooorrrrmmmm also repond to printAt:. A sample program plane.st can be found in /tests illustrating some of the features of forms. Refer to the Makesfiles in /prelude and /tests for more information. The second approach uses the plot(3) routines. On some terminals (the Tektronix 4014, for example) these routines can be set up to write directly to the terminal screen, rather than going through a postprocessing filter. If such a device is available, the symbol PLOT3 should be defined in parser/env.h, in addition appropriate loader commands (- l4014, for example) should be added to the symbol LIB in sources/Makefile. The functionality so provided is the ability to produce lines, circles and arcs. Various classes (Pen, PenSave and Form) for doing this are provided in the /prelude subdirec- tory, consult the Makefile for details. A test program (penshow) is provided in the /tests subdirectory. _7. _T_r_o_u_b_l_e_s_h_o_o_t_i_n_g Here are a few of the problems you might run into, and possible solutions: The first thing to suspect if you observe strange behavior is the fastloading feature. Try running the system with the -m flag, which will turn off fastloading. For example, on the 11/70 fastloading will inhibit the )i com- mand from working correctly, but no error messages will be generated. The appearance of a message such as ``_x_x_x: is not an identifier'', or of can't happen message number 23 is also a clue that fastloading does not work and should be disabled. Similarly, the appearance of the message ``no such context as: _x_x_x/stdsave'' during startup is an indica- tion that the file containing the saved binary form of the standard prelude either does not exist or is unreadable, or that the path given in parser/env.h is wrong. The appearence of the message ``xxx: not an identif- ier'' following a fast load or a )l command may be a sign that the environment pointer is being trashed. Try defin- ing the symbol ENVSAVE and recreating the system. Solutions to problems with fastloading are to try to to recreate the stdsave file in /prelude, or as a last resort to remove the definition for FASTDEFAULT from /parser/env.h, ``make clean'' and recompile everything. This latter step will configure a system that will not attempt fastloading unless explicitly called for. If the function _gamma is undefined following load for st. Solution: remove the definition for the symbol GAMMA, ``make clean'' and recompile. ``Can't happen number 1''. If you are running on a machine with small memory, your program creates too many objects and runs out of memory. If you are running on a vax or other large machine - your application is creating cycles or many many objects, probably a programming error. No output appears when you start the program, and if you type control-D all the output appears. Solution: define the symbol FLUSHREQ and recompile. Can't happen number 22 - either TEMPFILE is unreadable, or /prelude/standard does not exist. Systems that have trouble with long lines may have dif- ficulty with the file syms.c in /sources (there is one line in that file over 300 characters long). If necessary, this file can (and will be) automatically reconstructed from other files in the directory. Receiving error number 129 whenever any non-primitive class method is called may be a symptom of a clash of vari- able names. On older systems the variables runningProcess and runningInterpreter would clash on systems that did not support long variable names. The variable runningInter- preter (in process.c) has since been changed to presentIn- terpreter, so this problem should not occur in software taken from more recent distribution tapes. 129 errors can also be caused by bad preludes. Try removing all the .p files from /prelude and remaking stan- dard. (Frequently, if you receive an error when first building the prelude, some of the .p files will be incorrect). Note that /sources and /prelude have make instructions ``make clean'' which remove object files and are useful in insuring the files are in a clean state before starting a reconstruction of the system. _8. _F_u_r_t_h_e_r _D_i_s_t_r_i_b_u_t_i_o_n The Little Smalltalk system is public domain, and may be distributed further as long as proper attribution is given in all published references. In the interests of keeping the distribution up to date and as error free as possible, we wish to keep track of known sites using the system. People interested in being placed on the mailing list for future bug announcements and new version announcements should contact Professor Budd, at the address listed below. Changes, modifications, or improvements to the code or the standard library can be sub- mitted also, and will be considered for inclusion in future distributions. _9. _W_h_a_t _t_o _d_o _w_i_t_h _B_U_G_S Observed irregularities in Little Smalltalk behavior during execution (hereafter known as ``Bugs'') should be reported to: Professor Tim Budd Little Smalltalk Distribution Department of Computer Science The University of Arizona Tucson, Arizona 85721 USA CSNET address: budd@arizona UUCP address: ihnp4!arizona!budd The report of the bug should indicate whether it is reprodu- cible, and if so how it is manifested. If it is available, a description of the fix for the bug should be given, and it will be incorporated into future distributions. Periodi- cally, a listing of known bug fixes will be mailed to known sites. The Little Smalltalk system is distributed without responsibility for the performance of the system and without any guarantee of maintenance.