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/*
* picasm -- symtab.c
*
* symbol table handling
*
* Timo Rossi <trossi@iki.fi>
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "picasm.h"
#define HASH_TABLE_SIZE 127
typedef struct symbol *symtable[HASH_TABLE_SIZE];
/* structure for list of local symbol tables */
struct localtab {
struct localtab *next;
struct patch *patch_list;
symtable table;
};
static symtable global_symbol_table;
static struct localtab *local_table_list;
/*
* Compute a hash value from a string
*/
static unsigned int
hash(char *str)
{
unsigned int h, a;
h = 0;
while((a = *str++) != '\0') {
h = 17*h + a;
}
return h % HASH_TABLE_SIZE;
}
/*
* Initialize global and local symbol tables
*/
void
init_symtab(void)
{
struct symbol **sym;
int n;
for(sym = global_symbol_table, n = HASH_TABLE_SIZE;
n-- > 0; *sym++ = NULL)
;
local_table_list = NULL;
}
/*
* Add a new local symbol table
*/
void add_local_symtab(void)
{
struct localtab *tab;
struct symbol **symp;
int n;
tab = mem_alloc(sizeof(struct localtab));
for(symp = &tab->table[0], n = HASH_TABLE_SIZE;
n-- > 0; *symp++ = NULL)
;
tab->patch_list = NULL;
local_patch_list_ptr = &tab->patch_list;
tab->next = local_table_list;
local_table_list = tab;
local_level++;
}
/*
* Remove a local symbol table.
* The caller should check that local_level > 0 before calling this
*/
void remove_local_symtab(void)
{
int i;
struct localtab *tab;
struct symbol *sym, *sym2;
tab = local_table_list;
for(i = 0; i < HASH_TABLE_SIZE; i++) {
for(sym = tab->table[i]; sym != NULL; sym = sym2) {
sym2 = sym->next;
mem_free(sym);
}
}
local_table_list = tab->next;
if(local_table_list != NULL)
local_patch_list_ptr = &local_table_list->patch_list;
mem_free(tab);
local_level--;
}
/*
* Add a new symbol to the symbol table
*/
struct symbol *
add_symbol(char *name, int tab)
{
struct symbol *sym;
symtable *table;
int i;
table = (tab == SYMTAB_LOCAL ? &local_table_list->table :
&global_symbol_table);
if((sym = mem_alloc(sizeof(struct symbol) + strlen(name))) == NULL)
return NULL;
i = hash(name);
sym->next = (*table)[i];
(*table)[i] = sym;
strcpy(sym->name, name);
/* the caller must fill the value, type and flags fields */
return sym;
}
/*
* Try to find a symbol from the symbol table
*/
struct symbol *
lookup_symbol(char *name, int tab)
{
symtable *table;
struct symbol *sym;
int i;
table = (tab == SYMTAB_LOCAL ? &local_table_list->table :
&global_symbol_table);
i = hash(name);
for(sym = (*table)[i]; sym != NULL; sym = sym->next) {
if(strcmp(sym->name, name) == 0)
return sym;
}
return NULL;
}
/*
* symbol table output for listing (global symbols only)
*/
void dump_symtab(FILE *fp)
{
int i;
struct symbol *sym, *nsym, *s0, *s1;
struct symbol *syms = NULL;
for(i = 0; i < HASH_TABLE_SIZE; i++) {
for(sym = global_symbol_table[i]; sym != NULL; sym = nsym) {
nsym = sym->next;
for(s0 = NULL, s1 = syms; s1 != NULL; s0 = s1, s1 = s1->next) {
if(strcmp(s1->name, sym->name) > 0)
break;
}
if(s0 == NULL) {
sym->next = syms;
syms = sym;
} else {
sym->next = s0->next;
s0->next = sym;
}
}
}
fputs("\n\nSymbol Table:\nname decimal hex\n", fp);
for(sym = syms; sym != NULL; sym = sym->next) {
if(sym->type == SYM_MACRO)
fprintf(fp, "%-20s MACRO\n", sym->name);
else if(sym->type == SYM_FORWARD)
fprintf(fp, "%-20s UNDEFINED\n", sym->name);
else if(sym->type == SYM_DEFINED)
fprintf(fp, "%-20s %6ld 0x%04lx\n",
sym->name, sym->v.value, sym->v.value);
else
fprintf(fp, "%-20s ???\n", sym->name);
}
}
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