--- /dev/null
+/*
+ * tkMacOSXDebug.c --
+ *
+ * Implementation of Macintosh specific functions for debugging MacOS
+ * events, regions, etc...
+ *
+ * Copyright 2001-2009, Apple Inc.
+ * Copyright (c) 2006-2009 Daniel A. Steffen <das@users.sourceforge.net>
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tkMacOSXPrivate.h"
+#include "tkMacOSXDebug.h"
+
+#ifdef TK_MAC_DEBUG
+
+#include <mach-o/dyld.h>
+#include <mach-o/nlist.h>
+\f
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkMacOSXGetNamedDebugSymbol --
+ *
+ * Dynamically acquire address of a named symbol from a loaded dynamic
+ * library, so that we can use API that may not be available on all OS
+ * versions. For debugging purposes, if we cannot find the symbol with
+ * the usual dynamic library APIs, we manually walk the symbol table of
+ * the loaded library. This allows access to unexported symbols such as
+ * private_extern internal debugging functions. If module is NULL or the
+ * empty string, search all loaded libraries (could be very expensive and
+ * should be avoided).
+ *
+ * THIS FUCTION IS ONLY TO BE USED FOR DEBUGGING PURPOSES, IT MAY BREAK
+ * UNEXPECTEDLY IN THE FUTURE!
+ *
+ * Results:
+ * Address of given symbol or NULL if unavailable.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+MODULE_SCOPE void *
+TkMacOSXGetNamedDebugSymbol(
+ const char *module,
+ const char *symbol)
+{
+ void *addr = TkMacOSXGetNamedSymbol(module, symbol);
+
+#ifndef __LP64__
+ if (!addr) {
+ const struct mach_header *mh = NULL;
+ uint32_t i, n = _dyld_image_count();
+ size_t module_len = 0;
+
+ if (module && *module) {
+ module_len = strlen(module);
+ }
+ for (i = 0; i < n; i++) {
+ if (module && *module) {
+ /* Find image with given module name */
+ const char *name;
+ const char *path = _dyld_get_image_name(i);
+
+ if (!path) {
+ continue;
+ }
+ name = strrchr(path, '/') + 1;
+ if (strncmp(name, module, module_len) != 0) {
+ continue;
+ }
+ }
+ mh = _dyld_get_image_header(i);
+ if (mh) {
+ struct load_command *lc;
+ struct symtab_command *st = NULL;
+ struct segment_command *sg = NULL;
+ uint32_t j, m, nsect = 0, txtsectx = 0;
+
+ lc = (struct load_command*)((const char*) mh +
+ sizeof(struct mach_header));
+ m = mh->ncmds;
+ for (j = 0; j < m; j++) {
+ /* Find symbol table and index of __text section */
+ if (lc->cmd == LC_SEGMENT) {
+ /* Find last segment before symbol table */
+ sg = (struct segment_command*) lc;
+ if (!txtsectx) {
+ /* Count total sections until (__TEXT, __text) */
+ uint32_t k, ns = sg->nsects;
+
+ if (strcmp(sg->segname, SEG_TEXT) == 0) {
+ struct section *s = (struct section *)(
+ (char *)sg +
+ sizeof(struct segment_command));
+
+ for(k = 0; k < ns; k++) {
+ if (strcmp(s->sectname, SECT_TEXT) == 0) {
+ txtsectx = nsect+k+1;
+ break;
+ }
+ s++;
+ }
+ }
+ nsect += ns;
+ }
+ } else if (!st && lc->cmd == LC_SYMTAB) {
+ st = (struct symtab_command *) lc;
+ break;
+ }
+ lc = (struct load_command *)((char *) lc + lc->cmdsize);
+ }
+ if (st && sg && txtsectx) {
+ intptr_t base, slide = _dyld_get_image_vmaddr_slide(i);
+ char *strings;
+ struct nlist *sym;
+ uint32_t strsize = st->strsize;
+ int32_t strx;
+
+ /*
+ * Offset file positions by difference to actual position
+ * in memory of last segment before symbol table:
+ */
+
+ base = (intptr_t) sg->vmaddr + slide - sg->fileoff;
+ strings = (char *) (base + st->stroff);
+ sym = (struct nlist *) (base + st->symoff);
+ m = st->nsyms;
+ for (j = 0; j < m; j++) {
+ /* Find symbol with given name in __text section */
+ strx = sym->n_un.n_strx;
+ if ((sym->n_type & N_TYPE) == N_SECT &&
+ sym->n_sect == txtsectx &&
+ strx > 0 && (uint32_t) strx < strsize &&
+ strcmp(strings + strx, symbol) == 0) {
+ addr = (char*) sym->n_value + slide;
+ break;
+ }
+ sym++;
+ }
+ }
+ }
+ if (module && *module) {
+ /* If given a module name, only search corresponding image */
+ break;
+ }
+ }
+ }
+#endif /* __LP64__ */
+ return addr;
+}
+#endif /* TK_MAC_DEBUG */
+\f
+/*
+ * Local Variables:
+ * mode: objc
+ * c-basic-offset: 4
+ * fill-column: 79
+ * coding: utf-8
+ * End:
+ */
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