More readability cleanups.

[rmac] / rmac.c

//
// RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System
// RMAC.C - Main Application Code
// Copyright (C) 199x Landon Dyer, 2011 Reboot and Friends
// RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
// Source Utilised with the Kind Permission of Landon Dyer
//

#include "rmac.h"
#include "error.h"
#include "listing.h"
#include "procln.h"
#include "token.h"
#include "expr.h"
#include "sect.h"
#include "mark.h"
#include "macro.h"
#include "risca.h"
#include "direct.h"
#include "version.h"
#include "debug.h"
#include "symbol.h"
#include "object.h"

int perm_verb_flag;                                     // Permanently verbose, interactive mode
int list_flag;                                          // "-l" Listing flag on command line
int verb_flag;                                          // Be verbose about what's going on
int as68_flag;                                          // as68 kludge mode
int glob_flag;                                          // Assume undefined symbols are global
int lsym_flag;                                          // Include local symbols in object file
int sbra_flag;                                          // Warn about possible short branches
int obj_format;                                         // Object format flag
int debug;                                                      // [1..9] Enable debugging levels
int err_flag;                                           // '-e' specified
int err_fd;                                                     // File to write error messages to 
int rgpu, rdsp;                                         // Assembling Jaguar GPU or DSP code
int list_fd;                                            // File to write listing to
int regbank;                                            // RISC register bank
int segpadsize;                                         // Segment padding size
int in_main;                                            // In main memory flag for GPUMAIN
int endian;                                                     // Host processor endianess
char * objfname;                                        // Object filename pointer
char * firstfname;                                      // First source filename
char * cmdlnexec;                                       // Executable name, pointer to ARGV[0]
char * searchpath;                                      // Search path for include files 
char defname[] = "noname.o";            // Default output filename

// Under Windows and UNIX malloc() is an expensive call, so for small amounts
// of memory we allocate from a previously allocated buffer.

#define A_AMOUNT        4096                                // Amount to malloc() at a time
#define A_THRESH        64                                  // Use malloc() for amounts >= A_THRESH

static LONG a_amount;                                       // Amount left at a_ptr 
static char * a_ptr;                                        // Next free chunk
LONG amemtot;                                               // amem() total of requests

// Qsort; The THRESHold below is the insertion sort threshold, and has been adjusted
// for records of size 48 bytes.The MTHREShold is where we stop finding a better median.
 
#define THRESH          4                                   // Threshold for insertion
#define MTHRESH         6                                   // Threshold for median

static int (*qcmp)();                                       // The comparison routine
static int qsz;                                             // Size of each record
static int thresh;                                          // THRESHold in chars 
static int mthresh;                                         // MTHRESHold in chars


//
// qst: Do a quicksort. First, find the median element, and put that one in the
// first place as the discriminator. (This "median" is just the median of the
// first, last and middle elements). (Using this median instead of the first
// element is a big win). Then, the usual partitioning/swapping, followed by
// moving the discriminator into the right place. Then, figure out the sizes of
// the two partions, do the smaller one recursively and the larger one via a
// repeat of this code.  Stopping when there are less than THRESH elements in a
// partition and cleaning up with an insertion sort (in our caller) is a huge
// win. All data swaps are done in-line, which is space-losing but time-saving.
// (And there are only three places where this is done).
//
static int qst(char * base, char * max)
{
   char c, * i, * j, * jj;
   int ii;
   char * mid, * tmp;
   long lo, hi;

   /*
         * At the top here, lo is the number of characters of elements in the
         * current partition. (Which should be max - base).
         * Find the median of the first, last, and middle element and make
         * that the middle element. Set j to largest of first and middle.
         * If max is larger than that guy, then it's that guy, else compare
         * max with loser of first and take larger. Things are set up to
         * prefer the middle, then the first in case of ties.
         */
        lo = max - base;                /* number of elements as chars */

        do
        {
                mid = i = base + qsz * ((lo / qsz) >> 1);

                if (lo >= mthresh)
                {
                        j = (qcmp((jj = base), i) > 0 ? jj : i);

                        if (qcmp(j, (tmp = max - qsz)) > 0)
                        {
                                /* switch to first loser */
                                j = (j == jj ? i : jj);

                                if (qcmp(j, tmp) < 0)
                                        j = tmp;
                        }

                        if (j != i)
                        {
                                ii = qsz;

                                do
                                {
                                        c = *i;
                                        *i++ = *j;
                                        *j++ = c;
                                }
                                while (--ii);
                        }
                }

                /*
                 * Semi-standard quicksort partitioning/swapping
                 */
                for(i=base, j=max-qsz; ;)
                {
                        while (i < mid && qcmp(i, mid) <= 0)
                                i += qsz;

                        while (j > mid)
                        {
                                if (qcmp(mid, j) <= 0)
                                {
                                        j -= qsz;
                                        continue;
                                }

                                tmp = i + qsz;  /* value of i after swap */

                                if (i == mid)
                                {
                                        /* j <-> mid, new mid is j */
                                        mid = jj = j;
                                }
                                else
                                {
                                        /* i <-> j */
                                        jj = j;
                                        j -= qsz;
                                }

                                goto swap;
                        }

                        if (i == mid)
                        {
                                break;
                        }
                        else
                        {
                                /* i <-> mid, new mid is i */
                                jj = mid;
                                tmp = mid = i;  /* value of i after swap */
                                j -= qsz;
                        }
swap:
                        ii = qsz;

                        do
                        {
                                c = *i;
                                *i++ = *jj;
                                *jj++ = c;
                        }
                        while (--ii);

                        i = tmp;
                }

                /*
                 * Look at sizes of the two partitions, do the smaller
                 * one first by recursion, then do the larger one by
                 * making sure lo is its size, base and max are update
                 * correctly, and branching back.  But only repeat
                 * (recursively or by branching) if the partition is
                 * of at least size THRESH.
                 */
                i = (j = mid) + qsz;

                if ((lo = j - base) <= (hi = max - i))
                {
                        if (lo >= thresh)
                                qst(base, j);

                        base = i;
                        lo = hi;
                }
                else
                {
                        if (hi >= thresh)
                                qst(i, max);

                        max = j;
                }
        }
        while (lo >= thresh);

        return 0;
}


/*
 * qsort:
 * First, set up some global parameters for qst to share.  Then, quicksort
 * with qst(), and then a cleanup insertion sort ourselves.  Sound simple?
 * It's not...
 */
int rmac_qsort(char * base, int n, int size, int (*compar)())
{
        register char c, * i, * j, * lo, * hi;
        char * min, * max;

        if (n <= 1)
                return 0;

        qsz = size;
        qcmp = compar;
        thresh = qsz * THRESH;
        mthresh = qsz * MTHRESH;
        max = base + n * qsz;

        if (n >= THRESH)
        {
                qst(base, max);
                hi = base + thresh;
        }
        else
        {
                hi = max;
        }

        /*
         * First put smallest element, which must be in the first THRESH, in
         * the first position as a sentinel.  This is done just by searching
         * the first THRESH elements (or the first n if n < THRESH), finding
         * the min, and swapping it into the first position.
         */
        for(j=lo=base; (lo+=qsz)<hi;)
        {
                if (qcmp(j, lo) > 0)
                        j = lo;
        }

        if (j != base)
        {
                /* swap j into place */
                for(i=base, hi=base+qsz; i<hi;)
                {
                        c = *j;
                        *j++ = *i;
                        *i++ = c;
                }
        }

        /*
         * With our sentinel in place, we now run the following hyper-fast
         * insertion sort.  For each remaining element, min, from [1] to [n-1],
         * set hi to the index of the element AFTER which this one goes.
         * Then, do the standard insertion sort shift on a character at a time
         * basis for each element in the frob.
         */
        for(min=base; (hi=min+=qsz)<max;)
        {
                while (qcmp(hi -= qsz, min) > 0)
                        /* void */;

                if ((hi += qsz) != min)
                {
                        for(lo=min+qsz; --lo>=min;)
                        {
                                c = *lo;

                                for(i=j=lo; (j-=qsz)>=hi; i=j)
                                        *i = *j;

                                *i = c;
                        }
                }
        }

        return 0;
}


//
// Allocate memory; Panic and Quit if we Run Out
//
char * amem(LONG amount)
{
        char * p;

        if (amount & 1)                                           // Keep word alignment
                ++amount;

        if (amount < A_THRESH)
        {                                  // Honor *small* request
                if (a_amount < amount)
                {
                        a_ptr = amem(A_AMOUNT);
                        a_amount = A_AMOUNT;
                }

                p = a_ptr;
                a_ptr += amount;
                a_amount -= amount;
        }
        else
        {
                amemtot += amount;                                    // Bump total alloc
                p = (char *)malloc(amount);                           // Get memory from malloc

                if ((LONG)p == (LONG)NULL)
                        fatal("memory exhausted");

                memset(p, 0, amount);
        }

        return p;
}


//
// Copy stuff around, return pointer to dest+count+1 (doesn't handle overlap)
//
char * copy(char * dest, char * src, LONG count)
{
        while (count--)
                *dest++ = *src++;

        return dest;
}


//
// Clear a region of memory
//
void clear(char * dest, LONG count)
{
        while(count--)
                *dest++ = 0;
}


//
// Check to see if the string is a keyword. Returns -1, or a value from the
// 'accept[]' table
//
int kmatch(char * p, int * base, int * check, int * tab, int * accept)
{
        int state;
        int j;

        for(state=0; state>=0;)
        {
                j = base[state] + (int)tolowertab[*p];

                if (check[j] != state)
                {                               // Reject, character doesn't match
                        state = -1;                                        // No match 
                        break;
                }

                if (!*++p)
                {                                           // Must accept or reject at EOS
                        state = accept[j];                                 // (-1 on no terminal match) 
                        break;
                }

                state = tab[j];
        }

        return state;
}


//
// Auto-even a section
//
void autoeven(int sect)
{
        switchsect(sect);
        d_even();
        savsect();
}


//
// Manipulate file extension.
// `name' must be large enough to hold any possible filename.
// If `stripp' is nonzero, any old extension is removed.
// Then, if the file does not already have an extension,
// `extension' is appended to the filename.
//
char * fext(char * name, char * extension, int stripp)
{
        char * s, * beg;                                           // String pointers

        // Find beginning of "real" name
        beg = name + strlen(name) - 1;

        for(; beg>name; --beg)
        {
                if (*beg == SLASHCHAR)
                {
                        ++beg;
                        break;
                }
        }

        if (stripp)
        {                                             // Clobber any old extension
                for(s=beg; *s && *s!='.'; ++s) 
                        ;

                *s = '\0';
        }

        for(s=beg; *s!='.'; ++s)
        {
                if (!*s)
                {                                             // Append the new extension
                        strcat(beg, extension);
                        break;
                }
        }

        return name;
}


//
// Return `item'nth element of semicolon-seperated pathnames specified in the
// enviroment string `s'. Copy the pathname to `buf'.  Return 0 if the `item'
// nth path doesn't exist.
// 
// [`item' ranges from 0 to N-1, where N = #elements in search path]
//
int nthpath(char * env_var, int itemno, char * buf)
{
        char * s = searchpath;

        if (s == NULL)
                s = getenv(env_var);

        if (s == NULL)
                return 0;

        while (itemno--)
                while (*s != EOS && *s++ != ';')
                        ;

        if (*s == EOS)
                return 0;

        while (*s != EOS && *s != ';')
                *buf++ = *s++;

        *buf++ = EOS;

        return 1;
}


//
// Display Command Line Help
//
void display_help(void)
{
        printf("Usage:\n");
        printf("    %s [options] srcfile\n", cmdlnexec);
        printf("\n");
        printf("Options:\n");
        printf("   -? or -h              display usage information\n");
        printf("   -dsymbol[=value]      define symbol\n");
        printf("   -e[errorfile]         send error messages to file, not stdout\n");
        printf("   -f[format]            output object file format\n");
        printf("                         b: BSD (use this for Jaguar)\n");
        printf("   -i[path]              directory to search for include files\n");
        printf("   -l[filename]          create an output listing file\n");
        printf("   -o file               output file name\n");
        printf("   -r[size]              pad segments to boundary size specified\n");
        printf("                         w: word (2 bytes, default alignment)\n");
        printf("                         l: long (4 bytes)\n");
        printf("                         p: phrase (8 bytes)\n");
        printf("                         d: double phrase (16 bytes)\n");
        printf("                         q: quad phrase (32 bytes)\n");
        printf("   -s                    warn about possible short branches\n");
        printf("   -u                    force referenced and undefined symbols global\n");
        printf("   -v                    set verbose mode\n");
        printf("   -y[pagelen]           set page line length (default: 61)\n");
        printf("\n");
}


//
// Display Version Information
//
void display_version(void)
{
        printf("\nReboot's Macro Assembler for Atari Jaguar\n"); 
        printf("Copyright (C) 199x Landon Dyer, 2011 Reboot\n"); 
        printf("V%01i.%01i.%01i %s (%s)\n\n", MAJOR, MINOR, PATCH, __DATE__, PLATFORM);
}


// 
// Process Command Line Arguments and do an Assembly
//
int process(int argc, char ** argv)
{
        int argno;                                              // Argument number
        SYM * sy;                                               // Pointer to a symbol record
        char * s;                                               // String pointer
        int fd;                                                 // File descriptor
        char fnbuf[FNSIZ];                              // Filename buffer 
        int i;                                                  // Iterator

        errcnt = 0;                                             // Initialise error count
        listing = 0;                                    // Initialise listing level
        list_flag = 0;                                  // Initialise listing flag
        verb_flag = perm_verb_flag;             // Initialise verbose flag
        as68_flag = 0;                                  // Initialise as68 kludge mode
        glob_flag = 0;                                  // Initialise .globl flag
        sbra_flag = 0;                                  // Initialise short branch flag
        debug = 0;                                              // Initialise debug flag
        searchpath = NULL;                              // Initialise search path
        objfname = NULL;                                // Initialise object filename
        list_fname = NULL;                              // Initialise listing filename
        err_fname = NULL;                               // Initialise error filename
        obj_format = BSD;                               // Initialise object format
        firstfname = NULL;                              // Initialise first filename
        err_fd = ERROUT;                                // Initialise error file descriptor
        err_flag = 0;                                   // Initialise error flag
        rgpu = 0;                                               // Initialise GPU assembly flag
        rdsp = 0;                                               // Initialise DSP assembly flag
        lsym_flag = 1;                                  // Include local symbols in object file
        regbank = BANK_N;                               // No RISC register bank specified
        orgactive = 0;                                  // Not in RISC org section
        orgwarning = 0;                                 // No ORG warning issued
        a_amount = 0;
        segpadsize = 2;                                 // Initialise segment padding size
        in_main = 0;

        // Initialise modules
        init_sym();                                             // Symbol table
        init_token();                                   // Tokenizer
        init_procln();                                  // Line processor
        init_expr();                                    // Expression analyzer
        init_sect();                                    // Section manager / code generator
        init_mark();                                    // Mark tape-recorder
        init_macro();                                   // Macro processor
        init_list();                                    // Listing generator

        // Process command line arguments and assemble source files
        for(argno = 0; argno < argc; ++argno)
        {
                if (*argv[argno] == '-')
                {
                        switch (argv[argno][1])
                        {
                        case 'd':                                       // Define symbol
                        case 'D':
                                for(s=argv[argno]+2; *s!=EOS;)
                                {
                                        if (*s++ == '=')
                                        {
                                                s[-1] = EOS;
                                                break;
                                        }
                                }

                                if (argv[argno][2] == EOS)
                                {
                                        printf("-d: empty symbol\n");
                                        ++errcnt;
                                        return errcnt;
                                }

                                sy = lookup(argv[argno] + 2, 0, 0);

                                if (sy == NULL)
                                {
                                        sy = newsym(argv[argno] + 2, LABEL, 0);
                                        sy->svalue = 0;
                                }

                                sy->sattr = DEFINED | EQUATED | ABS;

                                if (*s)
                                        sy->svalue = (VALUE)atoi(s);
                                else
                                        sy->svalue = 0;

                                break;
                        case 'e':                                       // Redirect error message output
                        case 'E':
                                err_fname = argv[argno] + 2;
                                break;
                        case 'f':                                       // -f<format>
                        case 'F':
                                switch (argv[argno][2])
                                {
                                case EOS:
                                case 'b':                                 // -fb = BSD (Jaguar Recommended)
                                case 'B':
                                        obj_format = BSD;
                                        break;
                                default:
                                        printf("-f: unknown object format specified\n");
                                        ++errcnt;
                                        return errcnt;
                                }
                                break;
                        case 'g':                                       // Debugging flag
                        case 'G':
                                printf("Debugging flag (-g) not yet implemented\n");
                                break;
                        case 'i':                                       // Set directory search path
                        case 'I':
                                searchpath = argv[argno] + 2;
                                break;
                        case 'l':                                       // Produce listing file
                        case 'L':
                                list_fname = argv[argno] + 2;
                                listing = 1;
                                list_flag = 1;
                                ++lnsave;
                                break;
                        case 'o':                                       // Direct object file output
                        case 'O':
                                if (argv[argno][2] != EOS)
                                        objfname = argv[argno] + 2;
                                else
                                {
                                        if (++argno >= argc)
                                        {
                                                printf("Missing argument to -o");
                                                ++errcnt;
                                                return errcnt;
                                        }
                                        objfname = argv[argno];
                                }

                                break;
                        case 'r':                                       // Pad seg to requested boundary size
                        case 'R':
                                switch(argv[argno][2])
                                {
                                case 'w': case 'W': segpadsize = 2;  break;  
                                case 'l': case 'L': segpadsize = 4;  break;
                                case 'p': case 'P': segpadsize = 8;  break;
                                case 'd': case 'D': segpadsize = 16; break;
                                case 'q': case 'Q': segpadsize = 32; break;
                                default: segpadsize = 2; break;           // Effective autoeven();
                                }
                                break;
                        case 's':                                       // Warn about possible short branches
                        case 'S':
                                sbra_flag = 1;
                                break;
                        case 'u':                                       // Make undefined symbols .globl
                        case 'U':
                                glob_flag = 1;
                                break;
                        case 'v':                                       // Verbose flag
                        case 'V':
                                verb_flag++;

                                if (verb_flag > 1)
                                        display_version();

                                break;
                        case 'x':                                       // Turn on debugging
                        case 'X':
                                debug = 1;
                                printf("~ Debugging ON\n");
                                break;
                        case 'y':                                       // -y<pagelen>
                        case 'Y':
                                pagelen = atoi(argv[argno] + 2);

                                if (pagelen < 10)
                                {
                                        printf("-y: bad page length\n");
                                        ++errcnt;
                                        return errcnt;
                                }

                                break;
                        case EOS:                                       // Input is stdin
                                if (firstfname == NULL)                       // Kludge first filename
                                        firstfname = defname;

                                include(0, "(stdin)");
                                assemble();
                                break;
                        case 'h':                                       // Display command line usage
                        case 'H':
                        case '?':
                                display_version();
                                display_help();
                                ++errcnt;
                                break;
                        default:
                                display_version();
                                printf("Unknown switch: %s\n\n", argv[argno]);
                                display_help();
                                ++errcnt;
                                break;
                        }
                }
                else
                {
                        // Record first filename.
                        if (firstfname == NULL)
                                firstfname = argv[argno];

                        strcpy(fnbuf, argv[argno]);
                        fext(fnbuf, ".s", 0);
                        fd = open(fnbuf, 0);

                        if (fd < 0)
                        {
                                printf("Cannot open: %s\n", fnbuf);
                                ++errcnt;
                                continue;
                        }

                        include(fd, fnbuf);
                        assemble();
                }
        }

        // Wind-up processing;
        // o  save current section (no more code generation)
        // o  do auto-even of all sections (or boundary alignment as requested through '-r')
        // o  determine name of object file:
        //    -  "foo.o" for linkable output;
        //    -  "foo.prg" for GEMDOS executable (-p flag).
        savsect();

        for(i=TEXT; i<=BSS; i<<=1)
        {
                switchsect(i);

                switch(segpadsize)
                {
                case 2:  d_even();    break;
                case 4:  d_long();    break;
                case 8:  d_phrase();  break;
                case 16: d_dphrase(); break;
                case 32: d_qphrase(); break;
                }

                savsect();
        }

        if (objfname == NULL)
        {
                if (firstfname == NULL)
                        firstfname = defname;

                strcpy(fnbuf, firstfname);
                //fext(fnbuf, prg_flag ? ".prg" : ".o", 1);
                fext(fnbuf, ".o", 1);
                objfname = fnbuf;
        }

        // With one pass finished, go back and:
        // (1)   run through all the fixups and resolve forward references;
        // (1.5) ensure that remaining fixups can be handled by the linker
        //       (`lo68' format, extended (postfix) format....)
        // (2)   generate the output file image and symbol table;
        // (3)   generate relocation information from left-over fixups.
        fixups();                                                // Do all fixups
        stopmark();                                              // Stop mark tape-recorder

        if (errcnt == 0)
        {
                if ((fd = open(objfname, _OPEN_FLAGS, _PERM_MODE)) < 0)
                        cantcreat(objfname);

                if (verb_flag)
                {
                        s = "object";
                        printf("[Writing %s file: %s]\n", s, objfname);
                }

                object((WORD)fd);
                close(fd);

                if (errcnt != 0)
                        unlink(objfname);
        }

        if (list_flag)
        {
                if (verb_flag)
                        printf("[Wrapping-up listing file]\n");

                listing = 1;
                symtable();
                close(list_fd);
        }

        if (err_flag)
                close(err_fd);

        DEBUG dump_everything();

        return errcnt;
}


//
// Determine Processor Endianess
//
int get_endianess(void)
{
        int i = 1;
        char * p = (char *)&i;

        if (p[0] == 1)
                return 0;

        return 1;
}


//
// Application Entry Point; Handle the Command Line
//
int main(int argc, char ** argv)
{
        int status;
        int i;

        perm_verb_flag = 0;                             // Clobber "permanent" verbose flag
        cmdlnexec = argv[0];                    // Obtain executable name

        endian = get_endianess();               // Get processor endianess

        for(i=0; i<MAXFWDJUMPS; i++)
                fwdjump[i] = 0;

        // Full command line passed
        if (argc > 1)
        {
                status = process(argc - 1, argv + 1);              
        }
        else
        {
                display_version();
                display_help();
        }

        return status;
}