4.3BSD - /usr/src/new/icon/tran/mem.c

   1: /*
   2:  * Memory initialization and allocation for the translator.
   3:  */
   4: 
   5: #include "itran.h"
   6: #include "sym.h"
   7: #include "tree.h"
   8: 
   9: struct lentry **lhash;      /* hash area for local table */
  10: struct gentry **ghash;      /* hash area for global table */
  11: struct centry **chash;      /* hash area for constant table */
  12: struct ientry **ihash;      /* hash area for identifier table */
  13: 
  14: nodeptr       tree;     /* parse tree space */
  15: nodeptr       tend;     /* end of parse tree space */
  16: struct lentry *ltable;      /* local table */
  17: struct gentry *gtable;      /* global table */
  18: struct centry *ctable;      /* constant table */
  19: struct ientry *itable;      /* identifier table */
  20: 
  21: char *strings;          /* string space */
  22: char *send;         /* end of string space */
  23: 
  24: nodeptr        tfree;       /* free pointer for parse tree space */
  25: struct lentry *lfree;       /* free pointer for local table */
  26: struct gentry *gfree;       /* free pointer for global table */
  27: struct centry *ctfree;      /* free pointer to constant table */
  28: struct ientry *ifree;       /* free pointer for identifier table */
  29: char          *sfree;       /* free pointer for string space */
  30: 
  31: int tsize  = TSIZE;     /* initial size of parse tree space */
  32: int lsize  = LSIZE;     /* initial size of local table */
  33: int gsize  = GSIZE;     /* initial size of global table */
  34: int csize  = CSIZE;     /* initial size of constant table */
  35: int isize  = ISIZE;     /* initial size of identifier table */
  36: int ssize  = SSIZE;     /* initial size of string space */
  37: int lhsize = LHSIZE;        /* initial size of local hash table */
  38: int ghsize = GHSIZE;        /* initial size of global hash table */
  39: int chsize = CHSIZE;        /* initial size of constant hash table */
  40: int ihsize = IHSIZE;        /* initial size of identifier hash table */
  41: int lmask;          /* mask for local table hash */
  42: int gmask;          /* mask for global table hash */
  43: int cmask;          /* mask for constant table hash */
  44: int imask;          /* mask for identifier table hash */
  45: 
  46: char *memfree = NULL;
  47: 
  48: /*
  49:  * meminit does per-file initialization of various data structures used
  50:  *  by the translator.
  51:  */
  52: meminit()
  53:    {
  54:    register *p;
  55: 
  56:    if (memfree == NULL)
  57:       memalloc();       /* allocate data regions for first file */
  58:    /*
  59:     * Reset the free pointer for each region.
  60:     */
  61:    lfree = ltable;
  62:    gfree = gtable;
  63:    ctfree = ctable;
  64:    ifree = itable;
  65:    sfree = strings;
  66:    tfree = tree;
  67:    /*
  68:     * Zero out the hash tables.
  69:     */
  70:    for (p = (int *)lhash; p < (int *)&lhash[lhsize]; p++)
  71:       *p = NULL;
  72:    for (p = (int *)ghash; p < (int *)&ghash[ghsize]; p++)
  73:       *p = NULL;
  74:    for (p = (int *)chash; p < (int *)&chash[chsize]; p++)
  75:       *p = NULL;
  76:    for (p = (int *)ihash; p < (int *)&ihash[ihsize]; p++)
  77:       *p = NULL;
  78: 
  79:    /*
  80:     * Vestigial structures - these flags are only incremented after
  81:     *  a call to syserr.  Idea was apparently to count number of
  82:     *  entries in an overflowing table, but wasn't completely
  83:     *  implemented.
  84:     */
  85:    alclflg = 0;
  86:    alcgflg = 0;
  87:    alccflg = 0;
  88:    }
  89: 
  90: /*
  91:  * allocate gets n*size bytes of storage and returns a pointer to it.
  92:  */
  93: 
  94: char *allocate(n, size)
  95: int n, size;
  96:    {
  97:    register int need;
  98:    register char *mfree;
  99:    extern char *brk();
 100: 
 101:    need = n * size;
 102:    mfree = memfree;
 103:    if ((int)brk(memfree += need) == -1)
 104:       return (NULL);
 105:    return (mfree);
 106:    }
 107: 
 108: /*
 109:  * memalloc computes sizes of data regions needed by the translator
 110:  * obtains space for them, and initializes pointers to them
 111:  */
 112: 
 113: memalloc()
 114: {
 115: register int i;
 116: char *allocate();
 117: extern char *sbrk();
 118: 
 119: 
 120:    memfree = sbrk(0);
 121: 
 122:    /*
 123:     * Round sizes of hash tables for locals, globals, constants, and
 124:     *  identifiers to next larger power of two.  The corresponding
 125:     *  mask values are set to one less than the hash table size so that
 126:     *  an integer value can be &'d with the mask to produce a hash value.
 127:     *  (See [lgc]hasher in sym.h.)
 128:     */
 129:    for (i = 1; i < lhsize; i <<= 1) ;
 130:    lhsize = i;
 131:    lmask = i - 1;
 132:    for (i = 1; i < ghsize; i <<= 1) ;
 133:    ghsize = i;
 134:    gmask = i - 1;
 135:    for (i = 1; i < chsize; i <<= 1) ;
 136:    chsize = i;
 137:    cmask = i - 1;
 138:    for (i = 1; i < ihsize; i <<= 1) ;
 139:    ihsize = i;
 140:    imask = i - 1;
 141: 
 142:    /*
 143:     * Allocate the various data structures.
 144:     */
 145:    lhash = (struct lentry **)   allocate(lhsize, sizeof(struct lentry *));
 146:    ghash = (struct gentry **)   allocate(ghsize, sizeof(struct gentry *));
 147:    chash = (struct centry **)   allocate(chsize, sizeof(struct centry *));
 148:    ihash = (struct ientry **)   allocate(ihsize, sizeof(struct ientry *));
 149:    ltable = (struct lentry *)   allocate(lsize, sizeof(struct lentry));
 150:    gtable = (struct gentry *)   allocate(gsize, sizeof(struct gentry));
 151:    ctable = (struct centry *)   allocate(csize, sizeof(struct centry));
 152:    itable = (struct ientry *)   allocate(isize, sizeof(struct ientry));
 153:    tree = (nodeptr)     allocate(tsize, sizeof(int));
 154:    strings =            allocate(ssize, sizeof(char));
 155:    tend = (nodeptr)((int *)tree + tsize);
 156:    send = strings + ssize;
 157:    /*
 158:     * Check to see if there was enough memory.  This assumes that the
 159:     *  allocation for strings fails if any of the other allocations
 160:     *  failed.  Apparent bug - That assumption is not necessarily valid.
 161:     */
 162:    if (strings == NULL) {
 163:       fprintf(stderr, "Can't get enough memory\n");
 164:       exit(1);
 165:       }
 166: 
 167: }

Defined functions

Defined variables