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6867acc18e
Both C and C++ have "bool", "true" and "false" in lower case; C requires <stdbool.h> for this, in C++ it is an inherent type built into the compiler. Use those instead of the old macros; emulate with a simple typedef enum if unavailable.
484 lines
15 KiB
C
484 lines
15 KiB
C
/* labels.c label handling for the Netwide Assembler
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*
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* The Netwide Assembler is copyright (C) 1996 Simon Tatham and
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* Julian Hall. All rights reserved. The software is
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* redistributable under the licence given in the file "Licence"
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* distributed in the NASM archive.
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*/
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#include "compiler.h"
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <inttypes.h>
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#include "nasm.h"
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#include "nasmlib.h"
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#include "hashtbl.h"
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/*
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* A local label is one that begins with exactly one period. Things
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* that begin with _two_ periods are NASM-specific things.
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*
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* If TASM compatibility is enabled, a local label can also begin with
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* @@, so @@local is a TASM compatible local label. Note that we only
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* check for the first @ symbol, although TASM requires both.
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*/
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#define islocal(l) \
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(tasm_compatible_mode ? \
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(((l)[0] == '.' || (l)[0] == '@') && (l)[1] != '.') : \
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((l)[0] == '.' && (l)[1] != '.'))
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#define islocalchar(c) \
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(tasm_compatible_mode ? \
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((c) == '.' || (c) == '@') : \
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((c) == '.'))
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#define LABEL_BLOCK 128 /* no. of labels/block */
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#define LBLK_SIZE (LABEL_BLOCK*sizeof(union label))
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#define END_LIST -3 /* don't clash with NO_SEG! */
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#define END_BLOCK -2
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#define BOGUS_VALUE -4
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#define PERMTS_SIZE 4096 /* size of text blocks */
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#if (PERMTS_SIZE > IDLEN_MAX)
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#error "IPERMTS_SIZE must be less than or equal to IDLEN_MAX"
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#endif
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/* values for label.defn.is_global */
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#define DEFINED_BIT 1
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#define GLOBAL_BIT 2
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#define EXTERN_BIT 4
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#define NOT_DEFINED_YET 0
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#define TYPE_MASK 3
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#define LOCAL_SYMBOL (DEFINED_BIT)
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#define GLOBAL_PLACEHOLDER (GLOBAL_BIT)
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#define GLOBAL_SYMBOL (DEFINED_BIT|GLOBAL_BIT)
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union label { /* actual label structures */
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struct {
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int32_t segment, offset;
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char *label, *special;
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int is_global, is_norm;
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} defn;
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struct {
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int32_t movingon, dummy;
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union label *next;
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} admin;
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};
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struct permts { /* permanent text storage */
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struct permts *next; /* for the linked list */
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int size, usage; /* size and used space in ... */
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char data[PERMTS_SIZE]; /* ... the data block itself */
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};
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extern int global_offset_changed; /* defined in nasm.c */
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static struct hash_table *ltab; /* labels hash table */
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static union label *ldata; /* all label data blocks */
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static union label *lfree; /* labels free block */
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static struct permts *perm_head; /* start of perm. text storage */
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static struct permts *perm_tail; /* end of perm. text storage */
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static void init_block(union label *blk);
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static char *perm_copy(const char *string);
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static char *prevlabel;
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static int initialized = false;
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char lprefix[PREFIX_MAX] = { 0 };
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char lpostfix[PREFIX_MAX] = { 0 };
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/*
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* Internal routine: finds the `union label' corresponding to the
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* given label name. Creates a new one, if it isn't found, and if
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* `create' is true.
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*/
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static union label *find_label(char *label, int create)
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{
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char *prev;
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int prevlen, len;
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union label *lptr, **lpp;
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char label_str[IDLEN_MAX];
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struct hash_insert ip;
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if (islocal(label)) {
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prev = prevlabel;
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prevlen = strlen(prev);
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len = strlen(label);
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if (prevlen+len >= IDLEN_MAX)
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return NULL; /* Error... */
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memcpy(label_str, prev, prevlen);
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memcpy(label_str+prevlen, label, len+1);
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label = label_str;
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} else {
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prev = "";
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prevlen = 0;
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}
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lpp = (union label **) hash_find(ltab, label, &ip);
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lptr = lpp ? *lpp : NULL;
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if (lptr || !create)
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return lptr;
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/* Create a new label... */
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if (lfree->admin.movingon == END_BLOCK) {
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/*
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* must allocate a new block
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*/
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lfree->admin.next =
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(union label *)nasm_malloc(LBLK_SIZE);
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lfree = lfree->admin.next;
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init_block(lfree);
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}
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lfree->admin.movingon = BOGUS_VALUE;
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lfree->defn.label = perm_copy(label);
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lfree->defn.special = NULL;
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lfree->defn.is_global = NOT_DEFINED_YET;
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hash_add(&ip, lfree->defn.label, lfree);
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return lfree++;
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}
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int lookup_label(char *label, int32_t *segment, int32_t *offset)
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{
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union label *lptr;
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if (!initialized)
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return 0;
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lptr = find_label(label, 0);
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if (lptr && (lptr->defn.is_global & DEFINED_BIT)) {
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*segment = lptr->defn.segment;
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*offset = lptr->defn.offset;
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return 1;
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} else
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return 0;
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}
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int is_extern(char *label)
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{
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union label *lptr;
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if (!initialized)
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return 0;
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lptr = find_label(label, 0);
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if (lptr && (lptr->defn.is_global & EXTERN_BIT))
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return 1;
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else
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return 0;
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}
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void redefine_label(char *label, int32_t segment, int32_t offset, char *special,
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int is_norm, int isextrn, struct ofmt *ofmt,
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efunc error)
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{
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union label *lptr;
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int exi;
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/* This routine possibly ought to check for phase errors. Most assemblers
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* check for phase errors at this point. I don't know whether phase errors
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* are even possible, nor whether they are checked somewhere else
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*/
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(void)segment; /* Don't warn that this parameter is unused */
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(void)special; /* Don't warn that this parameter is unused */
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(void)is_norm; /* Don't warn that this parameter is unused */
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(void)isextrn; /* Don't warn that this parameter is unused */
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(void)ofmt; /* Don't warn that this parameter is unused */
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#ifdef DEBUG
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#if DEBUG<3
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if (!strncmp(label, "debugdump", 9))
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#endif
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error(ERR_DEBUG, "redefine_label (%s, %ld, %08lx, %s, %d, %d)",
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label, segment, offset, special, is_norm, isextrn);
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#endif
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lptr = find_label(label, 1);
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if (!lptr)
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error(ERR_PANIC, "can't find label `%s' on pass two", label);
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if (!islocal(label)) {
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if (!islocalchar(*label) && lptr->defn.is_norm)
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prevlabel = lptr->defn.label;
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}
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global_offset_changed |= (lptr->defn.offset != offset);
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lptr->defn.offset = offset;
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if (pass0 == 1) {
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exi = !!(lptr->defn.is_global & GLOBAL_BIT);
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if (exi) {
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char *xsymbol;
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int slen;
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slen = strlen(lprefix);
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slen += strlen(lptr->defn.label);
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slen += strlen(lpostfix);
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slen++; /* room for that null char */
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xsymbol = nasm_malloc(slen);
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snprintf(xsymbol, slen, "%s%s%s", lprefix, lptr->defn.label,
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lpostfix);
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ofmt->symdef(xsymbol, segment, offset, exi,
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special ? special : lptr->defn.special);
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ofmt->current_dfmt->debug_deflabel(xsymbol, segment, offset,
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exi,
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special ? special : lptr->
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defn.special);
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/** nasm_free(xsymbol); ! outobj.c stores the pointer; ouch!!! **/
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} else {
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if ((lptr->defn.is_global & (GLOBAL_BIT | EXTERN_BIT)) !=
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EXTERN_BIT) {
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ofmt->symdef(lptr->defn.label, segment, offset, exi,
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special ? special : lptr->defn.special);
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ofmt->current_dfmt->debug_deflabel(label, segment, offset,
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exi,
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special ? special :
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lptr->defn.special);
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}
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}
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}
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/* if (pass0 == 1) */
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}
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void define_label(char *label, int32_t segment, int32_t offset, char *special,
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int is_norm, int isextrn, struct ofmt *ofmt, efunc error)
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{
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union label *lptr;
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int exi;
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#ifdef DEBUG
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#if DEBUG<3
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if (!strncmp(label, "debugdump", 9))
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#endif
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error(ERR_DEBUG, "define_label (%s, %ld, %08lx, %s, %d, %d)",
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label, segment, offset, special, is_norm, isextrn);
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#endif
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lptr = find_label(label, 1);
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if (lptr->defn.is_global & DEFINED_BIT) {
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error(ERR_NONFATAL, "symbol `%s' redefined", label);
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return;
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}
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lptr->defn.is_global |= DEFINED_BIT;
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if (isextrn)
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lptr->defn.is_global |= EXTERN_BIT;
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if (!islocalchar(label[0]) && is_norm) /* not local, but not special either */
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prevlabel = lptr->defn.label;
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else if (islocal(label) && !*prevlabel) {
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error(ERR_NONFATAL, "attempt to define a local label before any"
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" non-local labels");
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}
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lptr->defn.segment = segment;
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lptr->defn.offset = offset;
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lptr->defn.is_norm = (!islocalchar(label[0]) && is_norm);
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if (pass0 == 1 || (!is_norm && !isextrn && (segment & 1))) {
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exi = !!(lptr->defn.is_global & GLOBAL_BIT);
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if (exi) {
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char *xsymbol;
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int slen;
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slen = strlen(lprefix);
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slen += strlen(lptr->defn.label);
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slen += strlen(lpostfix);
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slen++; /* room for that null char */
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xsymbol = nasm_malloc(slen);
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snprintf(xsymbol, slen, "%s%s%s", lprefix, lptr->defn.label,
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lpostfix);
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ofmt->symdef(xsymbol, segment, offset, exi,
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special ? special : lptr->defn.special);
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ofmt->current_dfmt->debug_deflabel(xsymbol, segment, offset,
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exi,
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special ? special : lptr->
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defn.special);
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/** nasm_free(xsymbol); ! outobj.c stores the pointer; ouch!!! **/
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} else {
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if ((lptr->defn.is_global & (GLOBAL_BIT | EXTERN_BIT)) !=
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EXTERN_BIT) {
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ofmt->symdef(lptr->defn.label, segment, offset, exi,
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special ? special : lptr->defn.special);
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ofmt->current_dfmt->debug_deflabel(label, segment, offset,
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exi,
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special ? special :
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lptr->defn.special);
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}
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}
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} /* if (pass0 == 1) */
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}
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void define_common(char *label, int32_t segment, int32_t size, char *special,
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struct ofmt *ofmt, efunc error)
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{
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union label *lptr;
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lptr = find_label(label, 1);
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if (lptr->defn.is_global & DEFINED_BIT) {
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error(ERR_NONFATAL, "symbol `%s' redefined", label);
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return;
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}
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lptr->defn.is_global |= DEFINED_BIT;
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if (!islocalchar(label[0])) /* not local, but not special either */
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prevlabel = lptr->defn.label;
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else
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error(ERR_NONFATAL, "attempt to define a local label as a "
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"common variable");
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lptr->defn.segment = segment;
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lptr->defn.offset = 0;
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ofmt->symdef(lptr->defn.label, segment, size, 2,
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special ? special : lptr->defn.special);
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ofmt->current_dfmt->debug_deflabel(lptr->defn.label, segment, size, 2,
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special ? special : lptr->defn.
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special);
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}
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void declare_as_global(char *label, char *special, efunc error)
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{
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union label *lptr;
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if (islocal(label)) {
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error(ERR_NONFATAL, "attempt to declare local symbol `%s' as"
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" global", label);
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return;
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}
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lptr = find_label(label, 1);
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switch (lptr->defn.is_global & TYPE_MASK) {
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case NOT_DEFINED_YET:
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lptr->defn.is_global = GLOBAL_PLACEHOLDER;
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lptr->defn.special = special ? perm_copy(special) : NULL;
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break;
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case GLOBAL_PLACEHOLDER: /* already done: silently ignore */
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case GLOBAL_SYMBOL:
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break;
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case LOCAL_SYMBOL:
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if (!lptr->defn.is_global & EXTERN_BIT)
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error(ERR_NONFATAL, "symbol `%s': GLOBAL directive must"
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" appear before symbol definition", label);
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break;
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}
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}
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int init_labels(void)
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{
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ltab = hash_init();
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ldata = lfree = (union label *)nasm_malloc(LBLK_SIZE);
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init_block(lfree);
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perm_head =
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perm_tail = (struct permts *)nasm_malloc(sizeof(struct permts));
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perm_head->next = NULL;
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perm_head->size = PERMTS_SIZE;
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perm_head->usage = 0;
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prevlabel = "";
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initialized = true;
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return 0;
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}
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void cleanup_labels(void)
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{
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union label *lptr, *lhold;
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initialized = false;
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hash_free(ltab);
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lptr = lhold = ldata;
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while (lptr) {
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lptr = &lptr[LABEL_BLOCK-1];
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lptr = lptr->admin.next;
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nasm_free(lhold);
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lhold = lptr;
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}
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while (perm_head) {
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perm_tail = perm_head;
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perm_head = perm_head->next;
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nasm_free(perm_tail);
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}
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}
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static void init_block(union label *blk)
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{
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int j;
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for (j = 0; j < LABEL_BLOCK - 1; j++)
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blk[j].admin.movingon = END_LIST;
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blk[LABEL_BLOCK - 1].admin.movingon = END_BLOCK;
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blk[LABEL_BLOCK - 1].admin.next = NULL;
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}
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static char *perm_copy(const char *string)
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{
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char *p;
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int len = strlen(string)+1;
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if (perm_tail->size - perm_tail->usage < len) {
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perm_tail->next =
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(struct permts *)nasm_malloc(sizeof(struct permts));
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perm_tail = perm_tail->next;
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perm_tail->next = NULL;
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perm_tail->size = PERMTS_SIZE;
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perm_tail->usage = 0;
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}
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p = perm_tail->data + perm_tail->usage;
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memcpy(p, string, len);
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perm_tail->usage += len;
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return p;
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}
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/*
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* Notes regarding bug involving redefinition of external segments.
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*
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* Up to and including v0.97, the following code didn't work. From 0.97
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* developers release 2 onwards, it will generate an error.
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*
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* EXTERN extlabel
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* newlabel EQU extlabel + 1
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*
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* The results of allowing this code through are that two import records
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* are generated, one for 'extlabel' and one for 'newlabel'.
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*
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* The reason for this is an inadequacy in the defined interface between
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* the label manager and the output formats. The problem lies in how the
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* output format driver tells that a label is an external label for which
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* a label import record must be produced. Most (all except bin?) produce
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* the record if the segment number of the label is not one of the internal
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* segments that the output driver is producing.
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*
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* A simple fix to this would be to make the output formats keep track of
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* which symbols they've produced import records for, and make them not
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* produce import records for segments that are already defined.
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*
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* The best way, which is slightly harder but reduces duplication of code
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* and should therefore make the entire system smaller and more stable is
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* to change the interface between assembler, define_label(), and
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* the output module. The changes that are needed are:
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*
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* The semantics of the 'isextern' flag passed to define_label() need
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* examining. This information may or may not tell us what we need to
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* know (ie should we be generating an import record at this point for this
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* label). If these aren't the semantics, the semantics should be changed
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* to this.
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*
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* The output module interface needs changing, so that the `isextern' flag
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* is passed to the module, so that it can be easily tested for.
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*/
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