CP/M/CPM_CDROM.iso/simtel/sigm/vols000/vol014/c.hlp

Text File | 1985-02-09 | 17KB | 489 lines

Invoking BDS C using C.SUB
Overview of the BDS C Language System
Overview -- C Compiler, Pass 1
Overview -- C Compiler, Pass 2
Overview -- C Linker
Overview -- C Librarian
Overview -- C Skeleton File
Variable Types
Braces
Variable Accessing
ARIES-1 C Library
Special I/O using CIO
:Invoking BDS C using C.SUB

     BD╙á ├á ma∙á bσ invokinτ eithe≥ b∙ thσ conventiona∞ mean≤á o≥á b∙ ì
usinτá thσá SUBMI╘ filσ C.SUB«á  Iµ thσ SUBMI╘ filσá i≤á used¼á i⌠á i≤ ì
engaged as follows --

          SUBMIT C filename

wherσá 'filenameºá i≤ thσ namσ oµ 'filename.C'¼á thσ filσ t∩á compile«  ì
Notσ tha⌠ thσ use≥ i≤ NO╘ t∩ t∩ typσ filename.C¼á bu⌠ i≤ jus⌠ t∩á typσ ì
filename.

     A≤á executioεá oµ thσ tw∩ passe≤ oµ thσ compile≥ anΣá thσá linke≥ ì
proceeds¼á thσá use≥á wil∞ bσ giveε thσ chancσ t∩ abor⌠ processinτá a⌠ ì
variou≤á critica∞á point≤á iεá thσ proces≤ b∙á thσá executioεá oµá thσ ì
ABORTSU┬á program«á  Iµá aεá erro≥ ha≤ occurreΣá durinτá thσá previou≤ ì
processing, ABORT when this program is executed.


:Overview of the BDS C Language System

    The main components of C are: 4 executable programs,
a standard library file, and one skeleton run-time subroutine
file.

A description of each follows:
:Overview -- C Compiler, Pass 1

CC1:    Because C loads the entire source file into memory
    in one shot, the compilation is broken up into two
    phases (not "passes", strictly; The two phases end
    up taking about 8 passes to actually implement),
    maximizing the amount of memory available for the
    source file.
    CC1, the first half of the compiler, accepts a C
    source file with any filename and extension (say,
    "foo.c") and writes out a temporary file (with the
    same filename and extension ".CCI") containg a symbol
    table and an encoded form of the source code.

    The file extension ".C" is NOT assumed for the
    input file, so saying "FOO" for "FOO.C" would not
    work.è

    If the source file name is preceded by a disk
    designation, then the input is taken from the specified
    disk and the ouput is also written to that disk.

    If any errors are detected during CC1, the output
    file will not be written.

    In addition to the name of the source file, a few
    options may also be specified on the command line
    by preceding the option list with a dash (-):

    s     causes undeclared identifiers to be implicitly
            declared as integer variables, wherever possible.

    hex digit (4-f)  sets symbol table size to the
             specified value (in K bytes);
             default is 8 (5 for versions x.xT.)


    For example,
        A>cc1 foobar.c -s6
    supresses errors for undefined variables and sets
    symbol table size to 6K bytes;
        A>cc1 zot.c -e
    sets symbol table size to 14K bytes.
    Note that the option list must contain no blanks.
        A>cc1 b:td.c
    takes the source file from disk B and writes the .CCI
    file to disk B (regardless of what the currently logged
    disk is.)

    On an 8080, speed is about 12 lines source/sec.

:Overview -- C Compiler, Pass 2

CC2:    This is the second half of the compiler. CC2 accepts
    a ".CCI" file as input, and writes out a ".CRL" file
    if no errors are detected. (CRL is mnemonic for
    'C ReLocatable')

    If all goes well, writing out of the CRL file is
    followed by deletion of the "CCI" file, and
    compilation is complete.

    As for CC1, if a disk is specified explicitly as in
        A>cc2 c:yahoo
    then the .CCI file is loaded from the specified disk
    and the .CRL file is written to that same disk.

    On an 8080, execution time =  about 35 lines/sec.

:Overview -- C Linker

CLINK:    This program links a "main" function from some
    CRL file together with C.CCC (for common system
    subroutines) and any subordinate functions which
    "main" may require (from perhaps many CRL files).

    A successful linkage causes a ".COM" file to be
    generated. At this point, the 8080 absolute
    machine code file is ready to be executed (for
    better or worse) as a transient command by CP/M.

    The first argument on the command line must be the
    name of a CRL file containing a "main" function. If
    the name is specified with an extension, then that
    extension is interpreted specially as indicating
    which disks are to be involved in the operation (this
    is akin to the mechanism ASM uses to determine source
    and destination disks.)

    For example, if the first argument to CLINK were
    given as:
        A>clink foo.bc
    then CLINK would interpret the "b" in ".bc" as
    specifying the disk on which "DEFF.CRL" and "C.CCC" are
    to be found, and the "c" in ".bc" as specifying which
    disk the .COM file is to be written to. Both of these
    values, if omitted, default to the currently logged in
    disk.
    The first argument may also be preceded by a disk
    designation, to specify where all .CRL files are to be
    searched for (by default). For example, the command
        A>clink b:zot.ac
    tells CLINK to get C.CCC and DEFF.CRL from disk A; to
    write the ouput file to disk C; and to find ZOT.CRL on
    disk B.


    Any other CRL files to search may also be specified
    on the command line (WITHOUT their .CRL suffixes),
    causing those to be searched in the order specified.
    The default disk to search will be the same disk from
    which the original CRL file was taken; this default
    can be overridden by specifying an explicit disk
    designation for any appropriate CRL file name needing
    it. For example,
        A>clink c:foo.bb bar a:zot fraz
    causes disk C to be searched for the files FOO.CRL,
    BAR.CRL and FRAZ.CRL, while disk A would be searched
    to find ZOT.CRL. Disk B is where CLINK would expect
    DEFF.CRL and C.CCC to reside, and the output would go
    to disk B also.


    When all given CRL files have been searched, CLINK
    will automatically search DEFF.CRL.

    If there are still some unresolved references, then
    CLINK will ask for input from the keyboard to try
    resolving them.

    There are also several options which may be
    specified on the command line. Each option must
    be preceded by a dash (-); the space between
    options and their argument (if needed) is optional.
    The presently supported options are:

    -s        Prints out load statistics;
    -t nnnn        Reserves location nnnn (hex) and
            above for user; default is to
            reserve no space. What this really
            does is to cause the first op in
            the object file to be
                lxi sp,nnnn
            instead of
                lxi sp,bdos.
    -o name        Causes the .COM file generated to
            have the given name. Default is
            the name of the first .CRL file
            given (the one with the "main"
            function.)

    -e xxxx        Sets start of data area to address
            xxxx, to maintain consistency between
            several separate .COM files when
            chaining (via the library function
            "exec") is used.
    -c        Specifies that the .COM file is to
            be chained to from another .COM file.
            If the resultant .COM file is invoked
            directly from CP/M instead of via the
            "exec" function, then ARGC & ARGV
            processing is suspended, since upon
            being chained to you wouldn't want
            ARGC & ARGV processing to take place.
                Note that if you use this
            option, you should also use the -e
            option to set the data area address
            equal to that of the chaining .COM
            file.



    Examples:
        A>clink foo bar
    gets "main" from the file FOO.CRL, searches for
    needed functions first in FOO.CRL and then, if needed,
    in BAR.CRL and DEFF.CRL. All files are assumed to
    reside on the currently logged in disk.

        A>clink b:ihtfp belle -s
    searches for IHTFP.CRL and BELLE.CRL on disk B; prints
    a statistics summary when linkage is complete. The
    files DEFF.CRL and C.CCC are assumed to reside on the
    currently logged in disk; output also goes to the
    currently logged in disk.

        A>clink b:ihtfp.aa -s belle -o zot
    is the same as the last example except: the output
    file is called ZOT.COM, DEFF.CRL and C.CCC are assumed
    to reside on A, and output goes to A.


        A>clink stoned -t7000 -s
    sets top of memory to 7000h and prints out load
    statistics. Current disk used for everything.

    Note that if the load statistics tell you that
    the "LAST ADDRESS" is greater than the "TOP OF
    MEMORY", the program hasn't got the chance of a
    snowball in hell of running correctly.

:Oveview -- C Librarian

CLIB:    This program maintains .CRL files, allows transfer
    of functions from one CRL file to another, etc. To
    invoke CLIB, just type
            A>clib
    Clib will print a line such as
        FUNCTION BUFFER SIZE = nnnnn
    specifying the largest function size that can be
    handled. Attempting to "transfer" or "extract" a
    function larger than this size could be destructive.

    Next CLIB will prompt with a "*". Typing "h" at
    this point will give you a command summary.

    Basically, you work CLIB by opening one to six
    CRL files (which then become associated with
    "file numbers"), diddling the files to your hearts
    content, closing all files which you altered, and
    typing control-C.


    The old version of any CRL file you change with CLIB
    is renamed to name.BRL (for Backup ReLative).

    A sample session of CLIB to, say, transfer the
    functions named "FOO", "BAR", and "ZOT" from
    a .CRL file named "DSSR" to one named "RTS" would
    go as follows:


    A>clib

    BD SOFTWARE C LIBRARIAN VERSION x.x
    FUNCTION BUFFER SIZE = xxxx BYTES

    * open 0 dssr
    * open 1 rts
    * t 0 1 foo
    * t 0 1 bar
    * t 0 1 zot
    * c 1
    * ^C

    A> ...


    The "open" commands prepare to do work on a .CRL file,
    and associate each .CRL file opened with a digit (0-5).
    The "transfer" commands tell CLIB to transfer the
    named function from the first file (named by file #)
    to the second file (also named by number).
    The "close" command need only be given for files
    which have been altered; since DSSR wasn't written
    to in the above example, it didn't need to be closed,
    but RTS did need to be closed.


DEFF.CRL:  This file contains the standard function library...
       all 60+ functions worth. See the BDS C User's Guide
       for documentation on these functions.
:Overview -- C Skeleton File

C.CCC:    The run-time skeleton file, containing code for
    processing the command line (generating argc and
    argv, for you UNIX lovers), room for file I/O
    buffers, some math subroutines, etc.



    Note on the BDS C compiler:

    THIS IS NOT AN INTERPRETER.

    Some hacks, such as BASIC-E, are billed as compilers
    but actually just do some preprocessing and then
    interpret the program. BDS C is a true compiler,
    generating not-too-optimal but nevertheless quick
    8080 code.

    For the gory details on the BDS C implementation, see
    my notes to APPENDIX A of the EXCELLENT book
        "The C Programming Language."

:Variable Types

    Variable types supported:
    int     char    unsigned    struct    union
    arrays (of one or two dimensions)
    pointers
    simple combinations of the above

    For example,
            char *foo[10][15];
    declares foo to be a two dimensional array of
    pointers to characters;

            char (*foo)();
    declares foo to be a pointer to a function returning
    a character;

            char *foo, bar, zot[10];
    declares foo to be a pointer to characters, bar to
    be a single char variable, ant zot to be an array
    of 10 characters.

:Braces

    If your keyboard doesn't support the '{' and '}'
    characters (open and close brace, for those of
    you whose printer doesn't know about ascii 7B and
    7D), the symbols 'begin' and 'end' may be
    substituted. Don't unless you have to; '{' and '}'
    take up less memory.
    The CONVERT program will perform this conversion,
    if necessary.

:Variable Accessing

    Since all functions in C may be used recursively, all
    variable accessing is done relative to a base-of-
    stack-frame pointer, kept in the BC register pair
    during execution. Note that it takes 8 bytes of code
    to transfer a simple local variable whose address isè        (Base of stack pointer) + foo
    to the HL register pair; The code appears as:

        lxi h,foo
        dad b
        mov a,m
        inx h
        mov h,m
        mov m,a .
    To get an array element or structure element is even
    more hairy. Facts like this are enough to make me
    REALLY wish Intel had bothered to implement a double
    byte indirect load instruction. Oh well.

:ARIES-1 C Library

     Thσá followinτá arσ thσ name≤ oµ thσ routine≤ availablσ iε thσá ├ ì
Librar∙ DEFF.CRL«á  The∙ arσ listeΣ herσ a≤ ß memor∙ convenience¼á anΣ ì
refer to the manual for further details.

1.  General Purpose Functions

     csw()          exit()         bdos(c,de)          peek(n)
     poke(n,b)      inp(n)         outp(n,b)           pause()
     sleep(n)       call(adr,h,a,b,d)                  abs(n)
     srand(n)       rand()         setmem(adr,count,byte)
     movmem(source,dest,count)     qsort(base,nel,width,compar)
       char *source, *dest;          char *base; int(*compar)();
     exec(name)
       char *name;

2.  Character Input/Output

     getchar()      ungetch(c)     kbhit()             putchar(c)
     puts(str)      char *gets(str)
       char *str;     char *str;
     printf(format,arg1,arg2,...)  scanf(format,arg1,arg2,...)
       char *format;                 char *format;

3.  String and Character Processing

     isalpha(c)     isupper(c)     islower(c)     isdigit(c)
       char c;        char c;        char c;        char c;
     touppper(c)    tolower(c)     isspace(c)     strcat(s1,s2)
       char c;        char c;        char c;        char *s1, *s2;
     strcmp(s1,s2)  strcpy(s1,s2)  strlen(str)    atoi(str)
      char *s1,*s2;  char *s1,*s2;  char *str;     char *str;
     initw(array,string)           initb(array,string)
       int *array; char *string;     char *array, *string;
     getval(strptr)
       char **strptr;

4.  File I/O

     creat(filename)               unlink(filename)
       char *filename;               char *filename;
     open(filename,mode)           close(fd)
       char *filename;
       {mode=0 - input, mode=1 - output, mode=2 - input and output}
     read(fd,buf,nbl)              write(fd,buf,nbl)
       char *buf;                    char *buf;
     seek(fd,offset,code)          tell(fd)
     fopen(filename,iobuf)         fcreat(filename,iobuf)
       char *filename;               char *filename;
       struct buf *iobuf;            struct buf *iobuf;
     getc(iobuf)                   putc(c,iobuf)
       struct buf *iobuf;            char c; struct buf *iobuf;
     getw(iobuf)                   putw(w,iobuf)
       struct buf *iobuf;            struct buf *iobuf;
     fflush(iobuf)
       struct buf *iobuf;

5.  Plotting Functions (for Memory-Mapped Video Boards)

     setplot(base,xsize,ysize)
     clrplot()
     plot(x,y,chr)
       char chr;
     txtplot(string,x,y,ropt)
       char *string;
     line(c,x1,y1,x2,y2)

6.  Plotting Functions for Hazeltine 1500

     clear()
     cplot(x,y,chr)
       char chr;
     ctxtplot(x,y,string)
       char *string;

7.  Special I/O -- CIO

     cio(fn) or cio(fn,arg)

          CI╧ indexe≤ directl∙ int∩ thσ BIO╙ Jum≡ Table«á  'fnº i≤ thσ ì
inde° offset¼á anΣ 'argº i≤ aε argumen⌠ passeΣ (u≡ t∩ 1╢á bits)«á  Thσ ì
offsets and functions permitted are --

     Offset    Function

       ░       CONS╘ -- Consolσ status╗á ReturneΣ valuσ ╜ ░ iµ n∩ cha≥ ì
                 ready, 255 if char ready
       1       CONIN -- Console input; Returned value = char typed
       2       CONOUT -- Console output; Input value = char to output
       3       LIST -- List output; Input value = char to output
       4       PUNCH -- Punch output; Input value = char to output
       5       READER -- Reader input; Returned value = char input
:Special I/O using CIO

     CIO is called by --

               cio(fn) or cio(fn,arg)

     CI╧ indexe≤ directl∙ int∩ thσ BIO╙ Jum≡ Table«  'fnº i≤ thσ inde° ì
offset¼á anΣ 'argº i≤ aε argumen⌠ passeΣ (u≡ t∩ 1╢ bits)«  Thσ offset≤ ì
anΣ function≤ permitteΣ arσ --

     Offset    Function

       ░       CONS╘ -- Consolσ status╗á ReturneΣ valuσ ╜ ░ iµ n∩ cha≥ ì
                 ready, 255 if char ready
       1       CONIN -- Console input; Returned value = char typed
       2       CONOUT -- Console output; Input value = char to output
       3       LIST -- List output; Input value = char to output
       4       PUNCH -- Punch output; Input value = char to output
       5       READER -- Reader input; Returned value = char input