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-rw-r--r--elf/do-lookup.h202
1 files changed, 202 insertions, 0 deletions
diff --git a/elf/do-lookup.h b/elf/do-lookup.h
new file mode 100644
index 0000000000..1a833be83a
--- /dev/null
+++ b/elf/do-lookup.h
@@ -0,0 +1,202 @@
+/* Look up a symbol in the loaded objects.
+   Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#if VERSIONED
+# define FCT do_lookup_versioned
+# define ARG const struct r_found_version *const version,
+#else
+# define FCT do_lookup
+# define ARG
+#endif
+
+/* Inner part of the lookup functions.  We return a value > 0 if we
+   found the symbol, the value 0 if nothing is found and < 0 if
+   something bad happened.  */
+static inline int
+FCT (const char *undef_name, unsigned long int hash,
+     const ElfW(Sym) *ref, struct sym_val *result,
+     struct r_scope_elem *scope, size_t i, const char *reference_name,
+     ARG struct link_map *skip, int reloc_type)
+{
+  struct link_map **list = scope->r_list;
+  size_t n = scope->r_nlist;
+  struct link_map *map;
+
+  do
+    {
+      const ElfW(Sym) *symtab;
+      const char *strtab;
+      const ElfW(Half) *verstab;
+      ElfW(Symndx) symidx;
+      const ElfW(Sym) *sym;
+#if ! VERSIONED
+      int num_versions = 0;
+      const ElfW(Sym) *versioned_sym = NULL;
+#endif
+
+      map = list[i];
+
+      /* Here come the extra test needed for `_dl_lookup_symbol_skip'.  */
+      if (skip != NULL && map == skip)
+	continue;
+
+      /* Skip objects that could not be opened, which can occur in trace
+	 mode.  */
+      if (map->l_opencount == 0)
+	continue;
+
+      /* Don't search the executable when resolving a copy reloc.  */
+      if (elf_machine_lookup_noexec_p (reloc_type)
+	  && map->l_type == lt_executable)
+	continue;
+
+      /* Skip objects without symbol tables.  */
+      if (map->l_info[DT_SYMTAB] == NULL)
+	continue;
+
+      /* Print some debugging info if wanted.  */
+      if (_dl_debug_symbols)
+	_dl_debug_message (1, "symbol=", undef_name, ";  lookup in file=",
+			   map->l_name[0] ? map->l_name : _dl_argv[0],
+			   "\n", NULL);
+
+      symtab = (const void *) map->l_info[DT_SYMTAB]->d_un.d_ptr;
+      strtab = (const void *) map->l_info[DT_STRTAB]->d_un.d_ptr;
+      verstab = map->l_versyms;
+
+      /* Search the appropriate hash bucket in this object's symbol table
+	 for a definition for the same symbol name.  */
+      for (symidx = map->l_buckets[hash % map->l_nbuckets];
+	   symidx != STN_UNDEF;
+	   symidx = map->l_chain[symidx])
+	{
+	  sym = &symtab[symidx];
+
+	  if (sym->st_value == 0 || /* No value.  */
+	      (elf_machine_lookup_noplt_p (reloc_type) /* Reject PLT entry.  */
+	       && sym->st_shndx == SHN_UNDEF))
+	    continue;
+
+	  if (ELFW(ST_TYPE) (sym->st_info) > STT_FUNC)
+	    /* Ignore all but STT_NOTYPE, STT_OBJECT and STT_FUNC entries
+	       since these are no code/data definitions.  */
+	    continue;
+
+	  if (sym != ref && strcmp (strtab + sym->st_name, undef_name))
+	    /* Not the symbol we are looking for.  */
+	    continue;
+
+#if VERSIONED
+	  if (verstab == NULL)
+	    {
+	      /* We need a versioned system but haven't found any.  If
+		 this is the object which is referenced in the verneed
+		 entry it is a bug in the library since a symbol must
+		 not simply disappear.  */
+	      if (version->filename != NULL
+		  && _dl_name_match_p (version->filename, map))
+		return -2;
+	      /* Otherwise we accept the symbol.  */
+	    }
+	  else
+	    {
+	      /* We can match the version information or use the
+		 default one if it is not hidden.  */
+	      ElfW(Half) ndx = verstab[symidx] & 0x7fff;
+	      if ((map->l_versions[ndx].hash != version->hash
+		   || strcmp (map->l_versions[ndx].name, version->name))
+		  && (version->hidden || map->l_versions[ndx].hash
+		      || (verstab[symidx] & 0x8000)))
+		/* It's not the version we want.  */
+		continue;
+	    }
+#else
+	  /* No specific version is selected.  When the object file
+	     also does not define a version we have a match.
+	     Otherwise we accept the default version, or in case there
+	     is only one version defined, this one version.  */
+	  if (verstab != NULL)
+	    {
+	      ElfW(Half) ndx = verstab[symidx] & 0x7fff;
+	      if (ndx > 2) /* map->l_versions[ndx].hash != 0) */
+		{
+		  /* Don't accept hidden symbols.  */
+		  if ((verstab[symidx] & 0x8000) == 0 && num_versions++ == 0)
+		    /* No version so far.  */
+		    versioned_sym = sym;
+		  continue;
+		}
+	    }
+#endif
+
+	  /* There cannot be another entry for this symbol so stop here.  */
+	  goto found_it;
+	}
+
+      /* If we have seen exactly one versioned symbol while we are
+	 looking for an unversioned symbol and the version is not the
+	 default version we still accept this symbol since there are
+	 no possible ambiguities.  */
+#if VERSIONED
+	sym = NULL;
+#else
+	sym = num_versions == 1 ? versioned_sym : NULL;
+#endif
+
+      if (sym != NULL)
+	{
+	found_it:
+	  switch (ELFW(ST_BIND) (sym->st_info))
+	    {
+	    case STB_GLOBAL:
+	      /* Global definition.  Just what we need.  */
+	      result->s = sym;
+	      result->m = map;
+	      return 1;
+	    case STB_WEAK:
+	      /* Weak definition.  Use this value if we don't find another.  */
+	      if (! result->s)
+		{
+		  result->s = sym;
+		  result->m = map;
+		}
+	      break;
+	    default:
+	      /* Local symbols are ignored.  */
+	      break;
+	    }
+	}
+
+#if VERSIONED
+      /* If this current map is the one mentioned in the verneed entry
+	 and we have not found a weak entry, it is a bug.  */
+      if (symidx == STN_UNDEF && version->filename != NULL
+	  && _dl_name_match_p (version->filename, map))
+	return -1;
+#endif
+    }
+  while (++i < n);
+
+  /* We have not found anything until now.  */
+  return 0;
+}
+
+#undef FCT
+#undef ARG
+#undef VERSIONED