Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libelf/gelf_getsymshndx.c b/libelf/gelf_getsymshndx.c
new file mode 100644
index 0000000..17c90fc
--- /dev/null
+++ b/libelf/gelf_getsymshndx.c
@@ -0,0 +1,136 @@
+/* Get symbol information and separate section index from symbol table
+ at the given index.
+ Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014, 2015 Red Hat, Inc.
+ This file is part of elfutils.
+ Written by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of either
+
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at
+ your option) any later version
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at
+ your option) any later version
+
+ or both in parallel, as here.
+
+ elfutils 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
+ General Public License for more details.
+
+ You should have received copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <gelf.h>
+#include <string.h>
+
+#include "libelfP.h"
+
+
+GElf_Sym *
+gelf_getsymshndx (Elf_Data *symdata, Elf_Data *shndxdata, int ndx,
+ GElf_Sym *dst, Elf32_Word *dstshndx)
+{
+ Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata;
+ Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata;
+ GElf_Sym *result = NULL;
+ Elf32_Word shndx = 0;
+
+ if (symdata == NULL)
+ return NULL;
+
+ if (unlikely (symdata->d_type != ELF_T_SYM)
+ || (likely (shndxdata_scn != NULL)
+ && unlikely (shndxdata->d_type != ELF_T_WORD)))
+ {
+ __libelf_seterrno (ELF_E_INVALID_HANDLE);
+ return NULL;
+ }
+
+ rwlock_rdlock (symdata_scn->s->elf->lock);
+
+ /* The user is not required to pass a data descriptor for an extended
+ section index table. */
+ if (likely (shndxdata_scn != NULL))
+ {
+ if (INVALID_NDX (ndx, Elf32_Word, &shndxdata_scn->d))
+ {
+ __libelf_seterrno (ELF_E_INVALID_INDEX);
+ goto out;
+ }
+
+ shndx = ((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx];
+ }
+
+ /* This is the one place where we have to take advantage of the fact
+ that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
+ The interface is broken so that it requires this hack. */
+ if (symdata_scn->s->elf->class == ELFCLASS32)
+ {
+ Elf32_Sym *src;
+
+ /* Here it gets a bit more complicated. The format of the symbol
+ table entries has to be adopted. The user better has provided
+ a buffer where we can store the information. While copying the
+ data we are converting the format. */
+ if (INVALID_NDX (ndx, Elf32_Sym, symdata))
+ {
+ __libelf_seterrno (ELF_E_INVALID_INDEX);
+ goto out;
+ }
+
+ src = &((Elf32_Sym *) symdata->d_buf)[ndx];
+
+ /* This might look like a simple copy operation but it's
+ not. There are zero- and sign-extensions going on. */
+#define COPY(name) \
+ dst->name = src->name
+ COPY (st_name);
+ /* Please note that we can simply copy the `st_info' element since
+ the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
+ for the 64 bit variant. */
+ COPY (st_info);
+ COPY (st_other);
+ COPY (st_shndx);
+ COPY (st_value);
+ COPY (st_size);
+ }
+ else
+ {
+ /* If this is a 64 bit object it's easy. */
+ assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym));
+
+ /* The data is already in the correct form. Just make sure the
+ index is OK. */
+ if (INVALID_NDX (ndx, GElf_Sym, symdata))
+ {
+ __libelf_seterrno (ELF_E_INVALID_INDEX);
+ goto out;
+ }
+
+ *dst = ((GElf_Sym *) symdata->d_buf)[ndx];
+ }
+
+ /* Now we can store the section index. */
+ if (dstshndx != NULL)
+ *dstshndx = shndx;
+
+ result = dst;
+
+ out:
+ rwlock_unlock (symdata_scn->s->elf->lock);
+
+ return result;
+}