diff options
Diffstat (limited to 'ld/table.c')
| -rw-r--r-- | ld/table.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/ld/table.c b/ld/table.c new file mode 100644 index 0000000..5260741 --- /dev/null +++ b/ld/table.c @@ -0,0 +1,205 @@ +/* table.c - table-handler module for linker */ + +/* Copyright (C) 1994 Bruce Evans */ + +#include "const.h" +#include "align.h" +#include "obj.h" +#include "type.h" +#include "globvar.h" + +#ifdef STDC_HEADERS_MISSING +void *malloc P((unsigned size)); +#else +#undef NULL +#include <stdlib.h> +#endif + +#define GOLDEN 157 /* GOLDEN/HASHTABSIZE approx golden ratio */ +#define HASHTABSIZE 256 + +PRIVATE struct symstruct *hashtab[HASHTABSIZE]; /* hash table */ +PRIVATE char *tableptr; /* next free spot in catchall table */ +PRIVATE char *tableend; /* ptr to spot after last in table */ + +FORWARD struct symstruct **gethashptr P((char *name)); + +/* initialise symbol table */ + +PUBLIC void syminit() +{ + unsigned i; + + for (i = sizeof(int) <= 2 ? 0xE000 : (unsigned) 0x38000; + i != 0; i -= 512) + if ((tableptr = malloc(i)) != NULL) + break; + if (tableptr == NULL) + outofmemory(); + tableend = tableptr + i; + for (i = 0; i < HASHTABSIZE; i++) + hashtab[i] = NULL; +} + +/* add named symbol to end of table - initialise only name and next fields */ +/* caller must not duplicate names of externals for findsym() to work */ + +PUBLIC struct symstruct *addsym(name) +char *name; +{ + struct symstruct **hashptr; + struct symstruct *oldsymptr; + struct symstruct *symptr; + + hashptr = gethashptr(name); + symptr = *hashptr; + while (symptr != NULL) + { + oldsymptr = symptr; + symptr = symptr->next; + } + align(tableptr); + symptr = (struct symstruct *) tableptr; + if ((tableptr = symptr->name + (strlen(name) + 1)) > tableend) + outofmemory(); + symptr->modptr = NULL; + symptr->next = NULL; + if (name != symptr->name) + strcpy(symptr->name, name); /* should't happen */ + if (*hashptr == NULL) + *hashptr = symptr; + else + oldsymptr->next = symptr; + return symptr; +} + +/* lookup named symbol */ + +PUBLIC struct symstruct *findsym(name) +char *name; +{ + struct symstruct *symptr; + + symptr = *gethashptr(name); + while (symptr != NULL && (!(symptr->flags & (E_MASK | I_MASK)) || + strcmp(symptr->name, name) != 0)) + symptr = symptr->next; + return symptr; +} + +/* convert name to a hash table ptr */ + +PRIVATE struct symstruct **gethashptr(name) +register char *name; +{ + register unsigned hashval; + + hashval = 0; + while (*name) + hashval = hashval * 2 + *name++; + return hashtab + ((hashval * GOLDEN) & (HASHTABSIZE - 1)); + +/* + +#asm + +GOLDEN EQU 157 +HASHTABSIZE EQU 256 + + CLRB can build value here since HASHTABSIZE <= 256 + LDA ,X + BEQ HASHVAL.EXIT +HASHVAL.LOOP + ADDB ,X+ + LSLB + LDA ,X + BNE HASHVAL.LOOP + RORB + LDA #GOLDEN + MUL +HASHVAL.EXIT +HASHVAL.EXIT + LDX #_hashtab + ABX discard A - same as taking mod HASHTABSIZE + ABX +#endasm + +*/ + +} + +/* move symbol descriptor entries to top of table (no error checking) */ + +PUBLIC char *moveup(nbytes) +unsigned nbytes; +{ + register char *source; + register char *target; + + source = tableptr; + target = tableend; + while (nbytes--) + *--target = *--source; + tableptr = source; + return tableend = target; +} + +/* our version of malloc */ + +PUBLIC char *ourmalloc(nbytes) +unsigned nbytes; +{ + char *allocptr; + + align(tableptr); + allocptr = tableptr; + if ((tableptr += nbytes) > tableend) + outofmemory(); + return allocptr; +} + +/* our version of free (release from bottom of table) */ + +PUBLIC void ourfree(cptr) +char *cptr; +{ + tableptr = cptr; +} + +/* read string from file into table at offset suitable for next symbol */ + +PUBLIC char *readstring() +{ + int c; + char *s; + char *start; + + align(tableptr); + start = s = ((struct symstruct *) tableptr)->name; + while (TRUE) + { + if (s >= tableend) + outofmemory(); + if ((c = readchar()) < 0) + prematureeof(); + if ((*s++ = c) == 0) + return start; + } + /* NOTREACHED */ +} + +/* release from top of table */ + +PUBLIC void release(cptr) +char *cptr; +{ + tableend = cptr; +} + +/* allocate space for string */ + +PUBLIC char *stralloc(s) +char *s; +{ + return strcpy(ourmalloc((unsigned) strlen(s) + 1), s); +} |