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-rw-r--r--labels.c527
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diff --git a/labels.c b/labels.c
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+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 1996-2009 The NASM Authors - All Rights Reserved
+ * See the file AUTHORS included with the NASM distribution for
+ * the specific copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * labels.c label handling for the Netwide Assembler
+ */
+
+#include "compiler.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <inttypes.h>
+
+#include "nasm.h"
+#include "nasmlib.h"
+#include "hashtbl.h"
+
+/*
+ * A local label is one that begins with exactly one period. Things
+ * that begin with _two_ periods are NASM-specific things.
+ *
+ * If TASM compatibility is enabled, a local label can also begin with
+ * @@, so @@local is a TASM compatible local label. Note that we only
+ * check for the first @ symbol, although TASM requires both.
+ */
+#define islocal(l) \
+ (tasm_compatible_mode ? \
+ (((l)[0] == '.' || (l)[0] == '@') && (l)[1] != '.') : \
+ ((l)[0] == '.' && (l)[1] != '.'))
+#define islocalchar(c) \
+ (tasm_compatible_mode ? \
+ ((c) == '.' || (c) == '@') : \
+ ((c) == '.'))
+
+#define LABEL_BLOCK 128 /* no. of labels/block */
+#define LBLK_SIZE (LABEL_BLOCK*sizeof(union label))
+
+#define END_LIST -3 /* don't clash with NO_SEG! */
+#define END_BLOCK -2
+#define BOGUS_VALUE -4
+
+#define PERMTS_SIZE 16384 /* size of text blocks */
+#if (PERMTS_SIZE < IDLEN_MAX)
+#error "IPERMTS_SIZE must be greater than or equal to IDLEN_MAX"
+#endif
+
+/* values for label.defn.is_global */
+#define DEFINED_BIT 1
+#define GLOBAL_BIT 2
+#define EXTERN_BIT 4
+#define COMMON_BIT 8
+
+#define NOT_DEFINED_YET 0
+#define TYPE_MASK 3
+#define LOCAL_SYMBOL (DEFINED_BIT)
+#define GLOBAL_PLACEHOLDER (GLOBAL_BIT)
+#define GLOBAL_SYMBOL (DEFINED_BIT|GLOBAL_BIT)
+
+union label { /* actual label structures */
+ struct {
+ int32_t segment;
+ int64_t offset;
+ char *label, *special;
+ int is_global, is_norm;
+ } defn;
+ struct {
+ int32_t movingon;
+ int64_t dummy;
+ union label *next;
+ } admin;
+};
+
+struct permts { /* permanent text storage */
+ struct permts *next; /* for the linked list */
+ int size, usage; /* size and used space in ... */
+ char data[PERMTS_SIZE]; /* ... the data block itself */
+};
+
+extern int64_t global_offset_changed; /* defined in nasm.c */
+
+static struct hash_table ltab; /* labels hash table */
+static union label *ldata; /* all label data blocks */
+static union label *lfree; /* labels free block */
+static struct permts *perm_head; /* start of perm. text storage */
+static struct permts *perm_tail; /* end of perm. text storage */
+
+static void init_block(union label *blk);
+static char *perm_copy(const char *string);
+
+static char *prevlabel;
+
+static bool initialized = false;
+
+char lprefix[PREFIX_MAX] = { 0 };
+char lpostfix[PREFIX_MAX] = { 0 };
+
+/*
+ * Internal routine: finds the `union label' corresponding to the
+ * given label name. Creates a new one, if it isn't found, and if
+ * `create' is true.
+ */
+static union label *find_label(char *label, int create)
+{
+ char *prev;
+ int prevlen, len;
+ union label *lptr, **lpp;
+ char label_str[IDLEN_MAX];
+ struct hash_insert ip;
+
+ if (islocal(label)) {
+ prev = prevlabel;
+ prevlen = strlen(prev);
+ len = strlen(label);
+ if (prevlen+len >= IDLEN_MAX)
+ return NULL; /* Error... */
+ memcpy(label_str, prev, prevlen);
+ memcpy(label_str+prevlen, label, len+1);
+ label = label_str;
+ } else {
+ prev = "";
+ prevlen = 0;
+ }
+
+ lpp = (union label **) hash_find(&ltab, label, &ip);
+ lptr = lpp ? *lpp : NULL;
+
+ if (lptr || !create)
+ return lptr;
+
+ /* Create a new label... */
+ if (lfree->admin.movingon == END_BLOCK) {
+ /*
+ * must allocate a new block
+ */
+ lfree->admin.next =
+ (union label *)nasm_malloc(LBLK_SIZE);
+ lfree = lfree->admin.next;
+ init_block(lfree);
+ }
+
+ lfree->admin.movingon = BOGUS_VALUE;
+ lfree->defn.label = perm_copy(label);
+ lfree->defn.special = NULL;
+ lfree->defn.is_global = NOT_DEFINED_YET;
+
+ hash_add(&ip, lfree->defn.label, lfree);
+ return lfree++;
+}
+
+bool lookup_label(char *label, int32_t *segment, int64_t *offset)
+{
+ union label *lptr;
+
+ if (!initialized)
+ return false;
+
+ lptr = find_label(label, 0);
+ if (lptr && (lptr->defn.is_global & DEFINED_BIT)) {
+ *segment = lptr->defn.segment;
+ *offset = lptr->defn.offset;
+ return true;
+ } else
+ return false;
+}
+
+bool is_extern(char *label)
+{
+ union label *lptr;
+
+ if (!initialized)
+ return false;
+
+ lptr = find_label(label, 0);
+ return (lptr && (lptr->defn.is_global & EXTERN_BIT));
+}
+
+void redefine_label(char *label, int32_t segment, int64_t offset, char *special,
+ bool is_norm, bool isextrn)
+{
+ union label *lptr;
+ int exi;
+
+ /* This routine possibly ought to check for phase errors. Most assemblers
+ * check for phase errors at this point. I don't know whether phase errors
+ * are even possible, nor whether they are checked somewhere else
+ */
+
+ (void)special; /* Don't warn that this parameter is unused */
+ (void)is_norm; /* Don't warn that this parameter is unused */
+ (void)isextrn; /* Don't warn that this parameter is unused */
+
+#ifdef DEBUG
+#if DEBUG<3
+ if (!strncmp(label, "debugdump", 9))
+#endif
+ nasm_error(ERR_DEBUG, "redefine_label (%s, %"PRIx32", %"PRIx64", %s, %d, %d)",
+ label, segment, offset, special, is_norm, isextrn);
+#endif
+
+ lptr = find_label(label, 1);
+ if (!lptr)
+ nasm_error(ERR_PANIC, "can't find label `%s' on pass two", label);
+
+ if (!islocal(label)) {
+ if (!islocalchar(*label) && lptr->defn.is_norm)
+ prevlabel = lptr->defn.label;
+ }
+
+ if (lptr->defn.offset != offset)
+ global_offset_changed++;
+
+ lptr->defn.offset = offset;
+ lptr->defn.segment = segment;
+
+ if (pass0 == 1) {
+ exi = !!(lptr->defn.is_global & GLOBAL_BIT);
+ if (exi) {
+ char *xsymbol;
+ int slen;
+ slen = strlen(lprefix);
+ slen += strlen(lptr->defn.label);
+ slen += strlen(lpostfix);
+ slen++; /* room for that null char */
+ xsymbol = nasm_malloc(slen);
+ snprintf(xsymbol, slen, "%s%s%s", lprefix, lptr->defn.label,
+ lpostfix);
+
+ ofmt->symdef(xsymbol, segment, offset, exi,
+ special ? special : lptr->defn.special);
+ ofmt->current_dfmt->debug_deflabel(xsymbol, segment, offset,
+ exi,
+ special ? special : lptr->
+ defn.special);
+/** nasm_free(xsymbol); ! outobj.c stores the pointer; ouch!!! **/
+ } else {
+ if ((lptr->defn.is_global & (GLOBAL_BIT | EXTERN_BIT)) !=
+ EXTERN_BIT) {
+ ofmt->symdef(lptr->defn.label, segment, offset, exi,
+ special ? special : lptr->defn.special);
+ ofmt->current_dfmt->debug_deflabel(label, segment, offset,
+ exi,
+ special ? special :
+ lptr->defn.special);
+ }
+ }
+ }
+ /* if (pass0 == 1) */
+}
+
+void define_label(char *label, int32_t segment, int64_t offset, char *special,
+ bool is_norm, bool isextrn)
+{
+ union label *lptr;
+ int exi;
+
+#ifdef DEBUG
+#if DEBUG<3
+ if (!strncmp(label, "debugdump", 9))
+#endif
+ nasm_error(ERR_DEBUG, "define_label (%s, %"PRIx32", %"PRIx64", %s, %d, %d)",
+ label, segment, offset, special, is_norm, isextrn);
+#endif
+ lptr = find_label(label, 1);
+ if (lptr->defn.is_global & DEFINED_BIT) {
+ nasm_error(ERR_NONFATAL, "symbol `%s' redefined", label);
+ return;
+ }
+ lptr->defn.is_global |= DEFINED_BIT;
+ if (isextrn)
+ lptr->defn.is_global |= EXTERN_BIT;
+
+ if (!islocalchar(label[0]) && is_norm) {
+ /* not local, but not special either */
+ prevlabel = lptr->defn.label;
+ } else if (islocal(label) && !*prevlabel) {
+ nasm_error(ERR_NONFATAL, "attempt to define a local label before any"
+ " non-local labels");
+ }
+
+ lptr->defn.segment = segment;
+ lptr->defn.offset = offset;
+ lptr->defn.is_norm = (!islocalchar(label[0]) && is_norm);
+
+ if (pass0 == 1 || (!is_norm && !isextrn && (segment > 0) && (segment & 1))) {
+ exi = !!(lptr->defn.is_global & GLOBAL_BIT);
+ if (exi) {
+ char *xsymbol;
+ int slen;
+ slen = strlen(lprefix);
+ slen += strlen(lptr->defn.label);
+ slen += strlen(lpostfix);
+ slen++; /* room for that null char */
+ xsymbol = nasm_malloc(slen);
+ snprintf(xsymbol, slen, "%s%s%s", lprefix, lptr->defn.label,
+ lpostfix);
+
+ ofmt->symdef(xsymbol, segment, offset, exi,
+ special ? special : lptr->defn.special);
+ ofmt->current_dfmt->debug_deflabel(xsymbol, segment, offset,
+ exi,
+ special ? special : lptr->
+ defn.special);
+/** nasm_free(xsymbol); ! outobj.c stores the pointer; ouch!!! **/
+ } else {
+ if ((lptr->defn.is_global & (GLOBAL_BIT | EXTERN_BIT)) !=
+ EXTERN_BIT) {
+ ofmt->symdef(lptr->defn.label, segment, offset, exi,
+ special ? special : lptr->defn.special);
+ ofmt->current_dfmt->debug_deflabel(label, segment, offset,
+ exi,
+ special ? special :
+ lptr->defn.special);
+ }
+ }
+ } /* if (pass0 == 1) */
+}
+
+void define_common(char *label, int32_t segment, int32_t size, char *special)
+{
+ union label *lptr;
+
+ lptr = find_label(label, 1);
+ if ((lptr->defn.is_global & DEFINED_BIT) &&
+ (passn == 1 || !(lptr->defn.is_global & COMMON_BIT))) {
+ nasm_error(ERR_NONFATAL, "symbol `%s' redefined", label);
+ return;
+ }
+ lptr->defn.is_global |= DEFINED_BIT|COMMON_BIT;
+
+ if (!islocalchar(label[0])) {
+ prevlabel = lptr->defn.label;
+ } else {
+ nasm_error(ERR_NONFATAL, "attempt to define a local label as a "
+ "common variable");
+ return;
+ }
+
+ lptr->defn.segment = segment;
+ lptr->defn.offset = 0;
+
+ if (pass0 == 0)
+ return;
+
+ ofmt->symdef(lptr->defn.label, segment, size, 2,
+ special ? special : lptr->defn.special);
+ ofmt->current_dfmt->debug_deflabel(lptr->defn.label, segment, size, 2,
+ special ? special : lptr->defn.
+ special);
+}
+
+void declare_as_global(char *label, char *special)
+{
+ union label *lptr;
+
+ if (islocal(label)) {
+ nasm_error(ERR_NONFATAL, "attempt to declare local symbol `%s' as"
+ " global", label);
+ return;
+ }
+ lptr = find_label(label, 1);
+ switch (lptr->defn.is_global & TYPE_MASK) {
+ case NOT_DEFINED_YET:
+ lptr->defn.is_global = GLOBAL_PLACEHOLDER;
+ lptr->defn.special = special ? perm_copy(special) : NULL;
+ break;
+ case GLOBAL_PLACEHOLDER: /* already done: silently ignore */
+ case GLOBAL_SYMBOL:
+ break;
+ case LOCAL_SYMBOL:
+ if (!(lptr->defn.is_global & EXTERN_BIT)) {
+ nasm_error(ERR_WARNING, "symbol `%s': GLOBAL directive "
+ "after symbol definition is an experimental feature", label);
+ lptr->defn.is_global = GLOBAL_SYMBOL;
+ }
+ break;
+ }
+}
+
+int init_labels(void)
+{
+ hash_init(&ltab, HASH_LARGE);
+
+ ldata = lfree = (union label *)nasm_malloc(LBLK_SIZE);
+ init_block(lfree);
+
+ perm_head =
+ perm_tail = (struct permts *)nasm_malloc(sizeof(struct permts));
+
+ perm_head->next = NULL;
+ perm_head->size = PERMTS_SIZE;
+ perm_head->usage = 0;
+
+ prevlabel = "";
+
+ initialized = true;
+
+ return 0;
+}
+
+void cleanup_labels(void)
+{
+ union label *lptr, *lhold;
+
+ initialized = false;
+
+ hash_free(&ltab);
+
+ lptr = lhold = ldata;
+ while (lptr) {
+ lptr = &lptr[LABEL_BLOCK-1];
+ lptr = lptr->admin.next;
+ nasm_free(lhold);
+ lhold = lptr;
+ }
+
+ while (perm_head) {
+ perm_tail = perm_head;
+ perm_head = perm_head->next;
+ nasm_free(perm_tail);
+ }
+}
+
+static void init_block(union label *blk)
+{
+ int j;
+
+ for (j = 0; j < LABEL_BLOCK - 1; j++)
+ blk[j].admin.movingon = END_LIST;
+ blk[LABEL_BLOCK - 1].admin.movingon = END_BLOCK;
+ blk[LABEL_BLOCK - 1].admin.next = NULL;
+}
+
+static char *perm_copy(const char *string)
+{
+ char *p;
+ int len = strlen(string)+1;
+
+ nasm_assert(len <= PERMTS_SIZE);
+
+ if (perm_tail->size - perm_tail->usage < len) {
+ perm_tail->next =
+ (struct permts *)nasm_malloc(sizeof(struct permts));
+ perm_tail = perm_tail->next;
+ perm_tail->next = NULL;
+ perm_tail->size = PERMTS_SIZE;
+ perm_tail->usage = 0;
+ }
+ p = perm_tail->data + perm_tail->usage;
+ memcpy(p, string, len);
+ perm_tail->usage += len;
+
+ return p;
+}
+
+char *local_scope(char *label)
+{
+ return islocal(label) ? prevlabel : "";
+}
+
+/*
+ * Notes regarding bug involving redefinition of external segments.
+ *
+ * Up to and including v0.97, the following code didn't work. From 0.97
+ * developers release 2 onwards, it will generate an error.
+ *
+ * EXTERN extlabel
+ * newlabel EQU extlabel + 1
+ *
+ * The results of allowing this code through are that two import records
+ * are generated, one for 'extlabel' and one for 'newlabel'.
+ *
+ * The reason for this is an inadequacy in the defined interface between
+ * the label manager and the output formats. The problem lies in how the
+ * output format driver tells that a label is an external label for which
+ * a label import record must be produced. Most (all except bin?) produce
+ * the record if the segment number of the label is not one of the internal
+ * segments that the output driver is producing.
+ *
+ * A simple fix to this would be to make the output formats keep track of
+ * which symbols they've produced import records for, and make them not
+ * produce import records for segments that are already defined.
+ *
+ * The best way, which is slightly harder but reduces duplication of code
+ * and should therefore make the entire system smaller and more stable is
+ * to change the interface between assembler, define_label(), and
+ * the output module. The changes that are needed are:
+ *
+ * The semantics of the 'isextern' flag passed to define_label() need
+ * examining. This information may or may not tell us what we need to
+ * know (ie should we be generating an import record at this point for this
+ * label). If these aren't the semantics, the semantics should be changed
+ * to this.
+ *
+ * The output module interface needs changing, so that the `isextern' flag
+ * is passed to the module, so that it can be easily tested for.
+ */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 11:56:46 +0000