Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libdwelf/libdwelf.h b/libdwelf/libdwelf.h
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+++ b/libdwelf/libdwelf.h
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+/* Interfaces for libdwelf. DWARF ELF Low-level Functions.
+   Copyright (C) 2014, 2015, 2016 Red Hat, Inc.
+   This file is part of elfutils.
+
+   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/>.  */
+
+#ifndef _LIBDWELF_H
+#define _LIBDWELF_H	1
+
+#include "libdw.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* DWARF ELF Low-level Functions (dwelf).
+   Functions starting with dwelf_elf will take a (libelf) Elf object as
+   first argument and might set elf_errno on error.  Functions starting
+   with dwelf_dwarf will take a (libdw) Dwarf object as first argument
+   and might set dwarf_errno on error.  */
+
+/* Returns the name and the CRC32 of the separate debug file from the
+   .gnu_debuglink section if found in the ELF.  Return NULL if the ELF
+   file didn't have a .gnu_debuglink section, had malformed data in the
+   section or some other error occured.  */
+extern const char *dwelf_elf_gnu_debuglink (Elf *elf, GElf_Word *crc);
+
+/* Returns the name and build ID from the .gnu_debugaltlink section if
+   found in the ELF.  On success, pointers to the name and build ID
+   are written to *NAMEP and *BUILDID_P, and the positive length of
+   the build ID is returned.  Returns 0 if the ELF lacks a
+   .gnu_debugaltlink section.  Returns -1 in case of malformed data or
+   other errors.  */
+extern ssize_t dwelf_dwarf_gnu_debugaltlink (Dwarf *dwarf,
+					     const char **namep,
+					     const void **build_idp);
+
+/* Returns the build ID as found in a NT_GNU_BUILD_ID note from either
+   a SHT_NOTE section or from a PT_NOTE segment if the ELF file
+   doesn't contain any section headers.  On success a pointer to the
+   build ID is written to *BUILDID_P, and the positive length of the
+   build ID is returned.  Returns 0 if the ELF lacks a NT_GNU_BUILD_ID
+   note.  Returns -1 in case of malformed data or other errors.  */
+extern ssize_t dwelf_elf_gnu_build_id (Elf *elf, const void **build_idp);
+
+/* Returns the size of the uncompressed data of a GNU compressed
+   section.  The section name should start with .zdebug (but this
+   isn't checked by this function).  If the section isn't compressed
+   (the section data doesn't start with ZLIB) -1 is returned. If an
+   error occured -1 is returned and elf_errno is set.  */
+extern ssize_t dwelf_scn_gnu_compressed_size (Elf_Scn *scn);
+
+/* ELF/DWARF string table handling.  */
+typedef struct Dwelf_Strtab Dwelf_Strtab;
+typedef struct Dwelf_Strent Dwelf_Strent;
+
+/* Create a new ELF/DWARF string table object in memory.  ELF string
+   tables have a required zero length null string at offset zero.
+   DWARF string tables don't require such a null entry (unless they
+   are shared with an ELF string table).  If NULLSTR is true then a
+   null entry is always created (even if the string table is empty
+   otherwise).  */
+extern Dwelf_Strtab *dwelf_strtab_init (bool nullstr);
+
+/* Add string STR to string table ST.  Returns NULL if no memory could
+   be allocated.  The given STR is owned by the called and must be
+   valid till dwelf_strtab_free is called.  dwelf_strtab_finalize
+   might copy the string into the final table and dwelf_strent_str
+   might return it, or a reference to an identical copy/substring
+   added to the string table.  */
+extern Dwelf_Strent *dwelf_strtab_add (Dwelf_Strtab *st, const char *str)
+  __nonnull_attribute__ (1, 2);
+
+/* This is an optimized version of dwelf_strtab_add if the length of
+   the string is already known.  LEN is the length of STR including
+   zero terminator.  Calling dwelf_strtab_add (st, str) is similar to
+   calling dwelf_strtab_len (st, str, strlen (str) + 1).  */
+extern Dwelf_Strent *dwelf_strtab_add_len (Dwelf_Strtab *st,
+					   const char *str, size_t len)
+  __nonnull_attribute__ (1, 2);
+
+/* Finalize string table ST and store size and memory location
+   information in DATA d_size and d_buf.  DATA d_type will be set to
+   ELF_T_BYTE, d_off will be zero, d_align will be 1 and d_version
+   will be set to EV_CURRENT.  If no memory could be allocated NULL is
+   returned and DATA->d_buf will be set to NULL.  Otherwise DATA will
+   be returned.  */
+extern Elf_Data *dwelf_strtab_finalize (Dwelf_Strtab *st,
+					Elf_Data *data)
+  __nonnull_attribute__ (1, 2);
+
+/* Get offset in string table for string associated with entry.  Only
+   valid after dwelf_strtab_finalize has been called.  */
+extern size_t dwelf_strent_off (Dwelf_Strent *se)
+  __nonnull_attribute__ (1);
+
+/* Return the string associated with the entry.  */
+extern const char *dwelf_strent_str (Dwelf_Strent *se)
+  __nonnull_attribute__ (1);
+
+/* Free resources allocated for the string table.  This invalidates
+   any Dwelf_Strent references returned earlier. */
+extern void dwelf_strtab_free (Dwelf_Strtab *st)
+  __nonnull_attribute__ (1);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* libdwelf.h */