Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 146 insertions, 0 deletions

diff --git a/REORG.TODO/elf/dl-addr.c b/REORG.TODO/elf/dl-addr.c
new file mode 100644
index 0000000000..1fac63d1a9
--- /dev/null
+++ b/REORG.TODO/elf/dl-addr.c
@@ -0,0 +1,146 @@
+/* Locate the shared object symbol nearest a given address.
+   Copyright (C) 1996-2017 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+#include <stddef.h>
+#include <ldsodefs.h>
+
+
+static inline void
+__attribute ((always_inline))
+determine_info (const ElfW(Addr) addr, struct link_map *match, Dl_info *info,
+		struct link_map **mapp, const ElfW(Sym) **symbolp)
+{
+  /* Now we know what object the address lies in.  */
+  info->dli_fname = match->l_name;
+  info->dli_fbase = (void *) match->l_map_start;
+
+  /* If this is the main program the information is incomplete.  */
+  if (__builtin_expect (match->l_name[0], 'a') == '\0'
+      && match->l_type == lt_executable)
+    info->dli_fname = _dl_argv[0];
+
+  const ElfW(Sym) *symtab
+    = (const ElfW(Sym) *) D_PTR (match, l_info[DT_SYMTAB]);
+  const char *strtab = (const char *) D_PTR (match, l_info[DT_STRTAB]);
+
+  ElfW(Word) strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
+
+  const ElfW(Sym) *matchsym = NULL;
+  if (match->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM
+		    + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] != NULL)
+    {
+      /* We look at all symbol table entries referenced by the hash
+	 table.  */
+      for (Elf_Symndx bucket = 0; bucket < match->l_nbuckets; ++bucket)
+	{
+	  Elf32_Word symndx = match->l_gnu_buckets[bucket];
+	  if (symndx != 0)
+	    {
+	      const Elf32_Word *hasharr = &match->l_gnu_chain_zero[symndx];
+
+	      do
+		{
+		  /* The hash table never references local symbols so
+		     we can omit that test here.  */
+		  if ((symtab[symndx].st_shndx != SHN_UNDEF
+		       || symtab[symndx].st_value != 0)
+		      && ELFW(ST_TYPE) (symtab[symndx].st_info) != STT_TLS
+		      && DL_ADDR_SYM_MATCH (match, &symtab[symndx],
+					    matchsym, addr)
+		      && symtab[symndx].st_name < strtabsize)
+		    matchsym = (ElfW(Sym) *) &symtab[symndx];
+
+		  ++symndx;
+		}
+	      while ((*hasharr++ & 1u) == 0);
+	    }
+	}
+    }
+  else
+    {
+      const ElfW(Sym) *symtabend;
+      if (match->l_info[DT_HASH] != NULL)
+	symtabend = (symtab
+		     + ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
+      else
+	/* There is no direct way to determine the number of symbols in the
+	   dynamic symbol table and no hash table is present.  The ELF
+	   binary is ill-formed but what shall we do?  Use the beginning of
+	   the string table which generally follows the symbol table.  */
+	symtabend = (const ElfW(Sym) *) strtab;
+
+      for (; (void *) symtab < (void *) symtabend; ++symtab)
+	if ((ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
+	     || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK)
+	    && __glibc_likely (!dl_symbol_visibility_binds_local_p (symtab))
+	    && ELFW(ST_TYPE) (symtab->st_info) != STT_TLS
+	    && (symtab->st_shndx != SHN_UNDEF
+		|| symtab->st_value != 0)
+	    && DL_ADDR_SYM_MATCH (match, symtab, matchsym, addr)
+	    && symtab->st_name < strtabsize)
+	  matchsym = (ElfW(Sym) *) symtab;
+    }
+
+  if (mapp)
+    *mapp = match;
+  if (symbolp)
+    *symbolp = matchsym;
+
+  if (matchsym)
+    {
+      /* We found a symbol close by.  Fill in its name and exact
+	 address.  */
+      lookup_t matchl = LOOKUP_VALUE (match);
+
+      info->dli_sname = strtab + matchsym->st_name;
+      info->dli_saddr = DL_SYMBOL_ADDRESS (matchl, matchsym);
+    }
+  else
+    {
+      /* No symbol matches.  We return only the containing object.  */
+      info->dli_sname = NULL;
+      info->dli_saddr = NULL;
+    }
+}
+
+
+int
+internal_function
+_dl_addr (const void *address, Dl_info *info,
+	  struct link_map **mapp, const ElfW(Sym) **symbolp)
+{
+  const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
+  int result = 0;
+
+  /* Protect against concurrent loads and unloads.  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+  struct link_map *l = _dl_find_dso_for_object (addr);
+
+  if (l)
+    {
+      determine_info (addr, l, info, mapp, symbolp);
+      result = 1;
+    }
+
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
+  return result;
+}
+libc_hidden_def (_dl_addr)