Return to assyms.h CVS log

Up to [CSRG BSD Unix] / 41BSD / cmd / as

Annotation of 41BSD/cmd/as/assyms.h, revision 1.1.1.1

1.1       root        1: /* Copyright (c) 1980 Regents of the University of California */
                      2: /* "@(#)assyms.h 4.2 8/15/80" */
                      3: /*
                      4:  *     To speed up walks through symbols defined in a particular
                      5:  *     segment, we buil up a table of pointers into the symbol table
                      6:  *     and a table of delimiters for each segment.  The delimiter for
                      7:  *     the particular segment points to the first word in that segment.
                      8:  */
                      9: 
                     10: extern struct  symtab  **symptrs;              /*dynamically allocated*/
                     11: extern struct  symtab  **symdelim[NLOC + NLOC + 1];
                     12: extern struct  symtab  **symptrub;
                     13: extern int     nsyms;                  /*number in the symbol table*/
                     14: extern int     njxxx;                  /*the number of jxxx entries in the table*/
                     15: extern int     nforgotten;             /*how many entries erroneously entered*/
                     16: extern int     nlabels;                /*how many labels in the symbol table*/
                     17: extern int     hshused;                /*how many hash slots used*/
                     18: 
                     19: #define SEGITERATE(segno, start, end, copointer, walkpointer, ubpointer, direction) \
                     20:        for(copointer = start == 0? symdelim[segno]:start,\
                     21:            ubpointer = end == 0 ? *symdelim[segno+1] : *(symdelim[segno]-1),\
                     22:            walkpointer = *copointer;\
                     23:            walkpointer != ubpointer;\
                     24:            walkpointer = * direction copointer)
                     25: 
                     26: #define SYMITERATE(copointer, walkpointer) \
                     27:        for(copointer = symptrs, \
                     28:            walkpointer = *copointer; \
                     29:            copointer < symptrub; \
                     30:            walkpointer = * ++ copointer)
                     31: /*
                     32:  *     Symbols are allocated in non contiguous chunks by extending
                     33:  *     the data area.  This way, it is extremely easy to
                     34:  *     allow virtual memory temporary files, change the length
                     35:  *     of NCPS, and allows for a much more flexible storage
                     36:  *     allocation
                     37:  */
                     38: 
                     39: #define SYMDALLOP      200
                     40: struct         allocbox{
                     41:        struct          allocbox        *nextalloc;
                     42:        struct          symtab          symslots[SYMDALLOP];
                     43: };
                     44: 
                     45: #ifdef FLEXNAMES
                     46: /*
                     47:  *     Names are allocated in a string pool.  String pools are linked
                     48:  *     together and are allocated dynamically by Calloc.
                     49:  */
                     50: #define        STRPOOLDALLOP   NCPS
                     51: struct strpool{
                     52:        struct  strpool *str_next;
                     53:        int             str_nalloc;
                     54:        char            str_names[STRPOOLDALLOP];
                     55: };
                     56: 
                     57: extern struct  strpool *strplhead;
                     58: #endif
                     59: 
                     60: extern struct  allocbox        *allochead;
                     61: extern struct  allocbox        *alloctail;
                     62: extern struct  symtab          *nextsym;
                     63: extern struct  allocbox        *newbox;
                     64: extern char                    *namebuffer;
                     65: extern int                     symsleft;
                     66: 
                     67: #define ALLOCQTY       sizeof (struct allocbox)
                     68: /*
                     69:  *     Iterate through all symbols in the symbol table in declaration
                     70:  *     order
                     71:  */
                     72: #define DECLITERATE(allocwalk, walkpointer, ubpointer) \
                     73:        for(allocwalk = allochead; \
                     74:            allocwalk != 0; \
                     75:            allocwalk = allocwalk->nextalloc) \
                     76:                for (walkpointer = &allocwalk->symslots[0],\
                     77:                        ubpointer = &allocwalk->symslots[SYMDALLOP], \
                     78:                        ubpointer = ubpointer > ( (struct symtab *)alloctail) \
                     79:                                 ? nextsym : ubpointer ;\
                     80:                     walkpointer < ubpointer; \
                     81:                     walkpointer++ )
                     82: /*
                     83:  *     The hash table is segmented, and dynamically extendable.
                     84:  *     We have a linked list of hash table segments; within each
                     85:  *     segment we use a quadratic rehash that touches no more than 1/2
                     86:  *     of the buckets in the hash table when probing.
                     87:  *     If the probe does not find the desired symbol, it moves to the
                     88:  *     next segment, or allocates a new segment.
                     89:  *
                     90:  *     Hash table segments are kept on the linked list with the first
                     91:  *     segment always first (that contains the reserved words) and
                     92:  *     the last added segment immediately after the first segment
                     93:  *     to hopefully gain something by locality of reference.
                     94:  */
                     95: struct hashdallop {
                     96:        int     h_nused;
                     97:        struct  hashdallop      *h_next;
                     98:        struct  symtab          *h_htab[NHASH];
                     99: };

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.