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/ChangeLog b/libdwelf/ChangeLog
new file mode 100644
index 0000000..a332655
--- /dev/null
+++ b/libdwelf/ChangeLog
@@ -0,0 +1,59 @@
+2015-10-11 Akihiko Odaki <akihiko.odaki.4i@stu.hosei.ac.jp>
+
+ * dwelf_strtab.c: Remove sys/param.h include.
+ (MIN): Remove definition.
+
+2016-07-08 Mark Wielaard <mjw@redhat.com>
+
+ * Makefile.am (libdwelf_a_SOURCES): Add dwelf_strtab.c.
+ * dwelf_strtab.c: New file.
+ * libdwelf.h (Dwelf_Strtab): New typedef.
+ (Dwelf_Strent): Likewise.
+ (dwelf_strtab_init): New function.
+ (dwelf_strtab_add): Likewise.
+ (dwelf_strtab_add_len): Likewise.
+ (dwelf_strtab_finalize): Likewise.
+ (dwelf_strent_off): Likewise.
+ (dwelf_strent_str): Likewise.
+ (dwelf_strtab_free): Likewise.
+
+2015-10-28 Mark Wielaard <mjw@redhat.com>
+
+ * Makefile.am (libdwelf_a_SOURCES): Add
+ dwelf_scn_gnu_compressed_size.c.
+ * dwelf_scn_gnu_compressed_size.c: Likewise.
+ * libdwelf.h (dwelf_scn_gnu_compressed_size): New declaration.
+
+2015-10-14 Chih-Hung Hsieh <chh@google.com>
+
+ * dwelf_elf_gnu_build_id.c (find_elf_build_id): Move nested function
+ 'check_notes' to file scope.
+
+2014-11-14 Mark Wielaard <mjw@redhat.com>
+
+ * dwelf_elf_gnu_debuglink.c (dwelf_elf_gnu_debuglink): Check d_buf
+ is not NULL.
+
+2014-04-30 Mark Wielaard <mjw@redhat.com>
+
+ * Makefile.am (AM_CPPFLAGS): Add libdwfl and libebl include dirs.
+ (libdwelf_a_SOURCES): Add dwelf_elf_gnu_build_id.c
+ * dwelf_elf_gnu_build_id.c: New file. Moved libdwfl function
+ __libdwfl_find_elf_build_id here.
+ * libdwelf.h (dwelf_elf_gnu_build_id): Declare new function.
+ * libdwelfP.h (dwelf_elf_gnu_build_id): Add internal declaration.
+
+2014-04-24 Florian Weimer <fweimer@redhat.com>
+
+ * dwelf_dwarf_gnu_debugaltlink.c: New file.
+ * Makefile.am (libdwelf_a_SOURCES): Add it.
+ * libdwelf.h (dwelf_dwarf_gnu_debugaltlink): Declare new function.
+ * libdwelfP.h (dwelf_dwarf_gnu_debugaltlink): Add internal
+ declaration.
+
+2014-04-11 Mark Wielaard <mjw@redhat.com>
+
+ * Makefile.am: New file.
+ * libdwelf.h: Likewise.
+ * libdwelfP.h: Likewise.
+ * dwelf_elf_gnu_debuglink.c: Likewise.
diff --git a/libdwelf/Makefile.am b/libdwelf/Makefile.am
new file mode 100644
index 0000000..7ca767a
--- /dev/null
+++ b/libdwelf/Makefile.am
@@ -0,0 +1,56 @@
+## Makefile.am for libdwelf library subdirectory in elfutils.
+##
+## Process this file with automake to create Makefile.in
+##
+## Copyright (C) 2014, 2015 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/>.
+##
+include $(top_srcdir)/config/eu.am
+AM_CPPFLAGS += -I$(srcdir)/../libelf -I$(srcdir)/../libdw \
+ -I$(srcdir)/../libdwfl -I$(srcdir)/../libebl
+VERSION = 1
+
+noinst_LIBRARIES = libdwelf.a libdwelf_pic.a
+
+pkginclude_HEADERS = libdwelf.h
+noinst_HEADERS = libdwelfP.h
+
+libdwelf_a_SOURCES = dwelf_elf_gnu_debuglink.c dwelf_dwarf_gnu_debugaltlink.c \
+ dwelf_elf_gnu_build_id.c dwelf_scn_gnu_compressed_size.c \
+ dwelf_strtab.c
+
+libdwelf = $(libdw)
+
+libdw = ../libdw/libdw.so
+libelf = ../libelf/libelf.so
+libebl = ../libebl/libebl.a
+libeu = ../lib/libeu.a
+
+libdwelf_pic_a_SOURCES =
+am_libdwelf_pic_a_OBJECTS = $(libdwelf_a_SOURCES:.c=.os)
+
+CLEANFILES += $(am_libdwelf_pic_a_OBJECTS)
diff --git a/libdwelf/dwelf_dwarf_gnu_debugaltlink.c b/libdwelf/dwelf_dwarf_gnu_debugaltlink.c
new file mode 100644
index 0000000..b8285d0
--- /dev/null
+++ b/libdwelf/dwelf_dwarf_gnu_debugaltlink.c
@@ -0,0 +1,62 @@
+/* Returns the file name and build ID stored in the .gnu_altdebuglink if found.
+ Copyright (C) 2014 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/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwelfP.h"
+
+ssize_t
+dwelf_dwarf_gnu_debugaltlink (Dwarf *dwarf,
+ const char **name_p,
+ const void **build_idp)
+{
+ Elf_Data *data = dwarf->sectiondata[IDX_gnu_debugaltlink];
+ if (data == NULL)
+ {
+ return 0;
+ }
+
+ const void *ptr = memchr (data->d_buf, '\0', data->d_size);
+ if (ptr == NULL)
+ {
+ __libdw_seterrno (DWARF_E_INVALID_ELF);
+ return -1;
+ }
+ size_t build_id_len = data->d_size - (ptr - data->d_buf + 1);
+ if (build_id_len == 0 || (size_t) (ssize_t) build_id_len != build_id_len)
+ {
+ __libdw_seterrno (DWARF_E_INVALID_ELF);
+ return -1;
+ }
+ *name_p = data->d_buf;
+ *build_idp = ptr + 1;
+ return build_id_len;
+}
+INTDEF(dwelf_dwarf_gnu_debugaltlink)
diff --git a/libdwelf/dwelf_elf_gnu_build_id.c b/libdwelf/dwelf_elf_gnu_build_id.c
new file mode 100644
index 0000000..8c78c70
--- /dev/null
+++ b/libdwelf/dwelf_elf_gnu_build_id.c
@@ -0,0 +1,156 @@
+/* Returns the build id if found in a NT_GNU_BUILD_ID note.
+ Copyright (C) 2014 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/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwelfP.h"
+#include "libdwflP.h"
+
+#define NO_VADDR ((GElf_Addr) -1l)
+
+static int
+check_notes (Elf_Data *data, GElf_Addr data_elfaddr,
+ const void **build_id_bits, GElf_Addr *build_id_elfaddr,
+ int *build_id_len)
+{
+ size_t pos = 0;
+ GElf_Nhdr nhdr;
+ size_t name_pos;
+ size_t desc_pos;
+ while ((pos = gelf_getnote (data, pos, &nhdr, &name_pos, &desc_pos)) > 0)
+ if (nhdr.n_type == NT_GNU_BUILD_ID
+ && nhdr.n_namesz == sizeof "GNU"
+ && !memcmp (data->d_buf + name_pos, "GNU", sizeof "GNU"))
+ {
+ *build_id_bits = data->d_buf + desc_pos;
+ *build_id_elfaddr = (data_elfaddr == NO_VADDR
+ ? 0 : data_elfaddr + desc_pos);
+ *build_id_len = nhdr.n_descsz;
+ return 1;
+ }
+ return 0;
+}
+
+/* Defined here for reuse. The dwelf interface doesn't care about the
+ address of the note, but libdwfl does. */
+static int
+find_elf_build_id (Dwfl_Module *mod, int e_type, Elf *elf,
+ const void **build_id_bits, GElf_Addr *build_id_elfaddr,
+ int *build_id_len)
+{
+ size_t shstrndx = SHN_UNDEF;
+ int result = 0;
+
+ Elf_Scn *scn = elf_nextscn (elf, NULL);
+
+ if (scn == NULL)
+ {
+ /* No sections, have to look for phdrs. */
+ size_t phnum;
+ if (unlikely (elf_getphdrnum (elf, &phnum) != 0))
+ {
+ if (mod != NULL)
+ __libdwfl_seterrno (DWFL_E_LIBELF);
+ return -1;
+ }
+ for (size_t i = 0; result == 0 && i < phnum; ++i)
+ {
+ GElf_Phdr phdr_mem;
+ GElf_Phdr *phdr = gelf_getphdr (elf, i, &phdr_mem);
+ if (likely (phdr != NULL) && phdr->p_type == PT_NOTE)
+ result = check_notes (elf_getdata_rawchunk (elf,
+ phdr->p_offset,
+ phdr->p_filesz,
+ ELF_T_NHDR),
+ phdr->p_vaddr,
+ build_id_bits,
+ build_id_elfaddr,
+ build_id_len);
+ }
+ }
+ else
+ do
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (likely (shdr != NULL) && shdr->sh_type == SHT_NOTE)
+ {
+ /* Determine the right sh_addr in this module. */
+ GElf_Addr vaddr = 0;
+ if (!(shdr->sh_flags & SHF_ALLOC))
+ vaddr = NO_VADDR;
+ else if (mod == NULL || e_type != ET_REL)
+ vaddr = shdr->sh_addr;
+ else if (__libdwfl_relocate_value (mod, elf, &shstrndx,
+ elf_ndxscn (scn), &vaddr))
+ vaddr = NO_VADDR;
+ result = check_notes (elf_getdata (scn, NULL), vaddr,
+ build_id_bits,
+ build_id_elfaddr,
+ build_id_len);
+ }
+ }
+ while (result == 0 && (scn = elf_nextscn (elf, scn)) != NULL);
+
+ return result;
+}
+
+int
+internal_function
+__libdwfl_find_elf_build_id (Dwfl_Module *mod, Elf *elf,
+ const void **build_id_bits,
+ GElf_Addr *build_id_elfaddr, int *build_id_len)
+{
+ GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (unlikely (ehdr == NULL))
+ {
+ __libdwfl_seterrno (DWFL_E_LIBELF);
+ return -1;
+ }
+ // MOD->E_TYPE is zero here.
+ assert (ehdr->e_type != ET_REL || mod != NULL);
+
+ return find_elf_build_id (mod, ehdr->e_type, elf,
+ build_id_bits, build_id_elfaddr, build_id_len);
+}
+
+ssize_t
+dwelf_elf_gnu_build_id (Elf *elf, const void **build_idp)
+{
+ GElf_Addr build_id_elfaddr;
+ int build_id_len;
+ int result = find_elf_build_id (NULL, ET_NONE, elf, build_idp,
+ &build_id_elfaddr, &build_id_len);
+ if (result > 0)
+ return build_id_len;
+
+ return result;
+}
+INTDEF(dwelf_elf_gnu_build_id)
diff --git a/libdwelf/dwelf_elf_gnu_debuglink.c b/libdwelf/dwelf_elf_gnu_debuglink.c
new file mode 100644
index 0000000..6e22cf6
--- /dev/null
+++ b/libdwelf/dwelf_elf_gnu_debuglink.c
@@ -0,0 +1,99 @@
+/* Returns the file name and crc stored in the .gnu_debuglink if found.
+ Copyright (C) 2014 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/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwelfP.h"
+
+const char *
+dwelf_elf_gnu_debuglink (Elf *elf, GElf_Word *crc)
+{
+ size_t shstrndx;
+ if (elf_getshdrstrndx (elf, &shstrndx) < 0)
+ return NULL;
+
+ Elf_Scn *scn = NULL;
+ while ((scn = elf_nextscn (elf, scn)) != NULL)
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ return NULL;
+
+ const char *name = elf_strptr (elf, shstrndx, shdr->sh_name);
+ if (name == NULL)
+ return NULL;
+
+ if (!strcmp (name, ".gnu_debuglink"))
+ break;
+ }
+
+ if (scn == NULL)
+ return NULL;
+
+ /* Found the .gnu_debuglink section. Extract its contents. */
+ Elf_Data *rawdata = elf_rawdata (scn, NULL);
+ if (rawdata == NULL || rawdata->d_buf == NULL)
+ return NULL;
+
+ /* The CRC comes after the zero-terminated file name,
+ (aligned up to 4 bytes) at the end of the section data. */
+ if (rawdata->d_size <= sizeof *crc
+ || memchr (rawdata->d_buf, '\0', rawdata->d_size - sizeof *crc) == NULL)
+ return NULL;
+
+ Elf_Data crcdata =
+ {
+ .d_type = ELF_T_WORD,
+ .d_buf = crc,
+ .d_size = sizeof *crc,
+ .d_version = EV_CURRENT,
+ };
+ Elf_Data conv =
+ {
+ .d_type = ELF_T_WORD,
+ .d_buf = rawdata->d_buf + rawdata->d_size - sizeof *crc,
+ .d_size = sizeof *crc,
+ .d_version = EV_CURRENT,
+ };
+
+ GElf_Ehdr ehdr_mem;
+ GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (ehdr == NULL)
+ return NULL;
+
+ Elf_Data *d = gelf_xlatetom (elf, &crcdata, &conv, ehdr->e_ident[EI_DATA]);
+ if (d == NULL)
+ return NULL;
+ assert (d == &crcdata);
+
+ return rawdata->d_buf;
+}
+INTDEF(dwelf_elf_gnu_debuglink)
diff --git a/libdwelf/dwelf_scn_gnu_compressed_size.c b/libdwelf/dwelf_scn_gnu_compressed_size.c
new file mode 100644
index 0000000..d39b702
--- /dev/null
+++ b/libdwelf/dwelf_scn_gnu_compressed_size.c
@@ -0,0 +1,77 @@
+/* Return size of GNU compressed section.
+ Copyright (C) 2015 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/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwelfP.h"
+#include "libelfP.h"
+
+ssize_t
+dwelf_scn_gnu_compressed_size (Elf_Scn *scn)
+{
+ if (scn == NULL)
+ return -1;
+
+ GElf_Shdr shdr;
+ if (gelf_getshdr (scn, &shdr) == NULL)
+ return -1;
+
+ /* Allocated or no bits sections can never be compressed. */
+ if ((shdr.sh_flags & SHF_ALLOC) != 0
+ || shdr.sh_type == SHT_NULL
+ || shdr.sh_type == SHT_NOBITS)
+ return -1;
+
+ Elf_Data *d = elf_rawdata (scn, NULL);
+ if (d == NULL)
+ return -1;
+
+ if (d->d_size >= 4 + 8
+ && memcmp (d->d_buf, "ZLIB", 4) == 0)
+ {
+ /* There is a 12-byte header of "ZLIB" followed by
+ an 8-byte big-endian size. There is only one type and
+ alignment isn't preserved separately. */
+ uint64_t size;
+ memcpy (&size, d->d_buf + 4, sizeof size);
+ size = be64toh (size);
+
+ /* One more sanity check, size should be bigger than original
+ data size plus some overhead (4 chars ZLIB + 8 bytes size + 6
+ bytes zlib stream overhead + 5 bytes overhead max for one 16K
+ block) and should fit into a size_t. */
+ if (size + 4 + 8 + 6 + 5 < d->d_size || size > SIZE_MAX)
+ return -1;
+
+ return size;
+ }
+
+ return -1;
+}
diff --git a/libdwelf/dwelf_strtab.c b/libdwelf/dwelf_strtab.c
new file mode 100644
index 0000000..01e091c
--- /dev/null
+++ b/libdwelf/dwelf_strtab.c
@@ -0,0 +1,360 @@
+/* ELF/DWARF string table handling.
+ Copyright (C) 2000, 2001, 2002, 2005, 2016 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 <inttypes.h>
+#include <libelf.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libdwelfP.h"
+#include <system.h>
+
+
+struct Dwelf_Strent
+{
+ const char *string;
+ size_t len;
+ struct Dwelf_Strent *next;
+ struct Dwelf_Strent *left;
+ struct Dwelf_Strent *right;
+ size_t offset;
+ char reverse[0];
+};
+
+
+struct memoryblock
+{
+ struct memoryblock *next;
+ char memory[0];
+};
+
+
+struct Dwelf_Strtab
+{
+ struct Dwelf_Strent *root;
+ struct memoryblock *memory;
+ char *backp;
+ size_t left;
+ size_t total;
+ bool nullstr;
+
+ struct Dwelf_Strent null;
+};
+
+
+/* Cache for the pagesize. */
+static size_t ps;
+/* We correct this value a bit so that `malloc' is not allocating more
+ than a page. */
+#define MALLOC_OVERHEAD (2 * sizeof (void *))
+
+
+Dwelf_Strtab *
+dwelf_strtab_init (bool nullstr)
+{
+ if (ps == 0)
+ {
+ ps = sysconf (_SC_PAGESIZE);
+ assert (sizeof (struct memoryblock) < ps - MALLOC_OVERHEAD);
+ }
+
+ Dwelf_Strtab *ret
+ = (Dwelf_Strtab *) calloc (1, sizeof (struct Dwelf_Strtab));
+ if (ret != NULL)
+ {
+ ret->nullstr = nullstr;
+
+ if (nullstr)
+ {
+ ret->null.len = 1;
+ ret->null.string = "";
+ }
+ }
+
+ return ret;
+}
+
+
+static int
+morememory (Dwelf_Strtab *st, size_t len)
+{
+ size_t overhead = offsetof (struct memoryblock, memory);
+ len += overhead + MALLOC_OVERHEAD;
+
+ /* Allocate nearest multiple of pagesize >= len. */
+ len = ((len / ps) + (len % ps != 0)) * ps - MALLOC_OVERHEAD;
+
+ struct memoryblock *newmem = (struct memoryblock *) malloc (len);
+ if (newmem == NULL)
+ return 1;
+
+ newmem->next = st->memory;
+ st->memory = newmem;
+ st->backp = newmem->memory;
+ st->left = len - overhead;
+
+ return 0;
+}
+
+
+void
+dwelf_strtab_free (Dwelf_Strtab *st)
+{
+ struct memoryblock *mb = st->memory;
+
+ while (mb != NULL)
+ {
+ void *old = mb;
+ mb = mb->next;
+ free (old);
+ }
+
+ free (st);
+}
+
+
+static Dwelf_Strent *
+newstring (Dwelf_Strtab *st, const char *str, size_t len)
+{
+ /* Compute the amount of padding needed to make the structure aligned. */
+ size_t align = ((__alignof__ (struct Dwelf_Strent)
+ - (((uintptr_t) st->backp)
+ & (__alignof__ (struct Dwelf_Strent) - 1)))
+ & (__alignof__ (struct Dwelf_Strent) - 1));
+
+ /* Make sure there is enough room in the memory block. */
+ if (st->left < align + sizeof (struct Dwelf_Strent) + len)
+ {
+ if (morememory (st, sizeof (struct Dwelf_Strent) + len))
+ return NULL;
+
+ align = 0;
+ }
+
+ /* Create the reserved string. */
+ Dwelf_Strent *newstr = (Dwelf_Strent *) (st->backp + align);
+ newstr->string = str;
+ newstr->len = len;
+ newstr->next = NULL;
+ newstr->left = NULL;
+ newstr->right = NULL;
+ newstr->offset = 0;
+ for (int i = len - 2; i >= 0; --i)
+ newstr->reverse[i] = str[len - 2 - i];
+ newstr->reverse[len - 1] = '\0';
+ st->backp += align + sizeof (struct Dwelf_Strent) + len;
+ st->left -= align + sizeof (struct Dwelf_Strent) + len;
+
+ return newstr;
+}
+
+
+/* XXX This function should definitely be rewritten to use a balancing
+ tree algorith (AVL, red-black trees). For now a simple, correct
+ implementation is enough. */
+static Dwelf_Strent **
+searchstring (Dwelf_Strent **sep, Dwelf_Strent *newstr)
+{
+ /* More strings? */
+ if (*sep == NULL)
+ {
+ *sep = newstr;
+ return sep;
+ }
+
+ /* Compare the strings. */
+ int cmpres = memcmp ((*sep)->reverse, newstr->reverse,
+ MIN ((*sep)->len, newstr->len) - 1);
+ if (cmpres == 0)
+ /* We found a matching string. */
+ return sep;
+ else if (cmpres > 0)
+ return searchstring (&(*sep)->left, newstr);
+ else
+ return searchstring (&(*sep)->right, newstr);
+}
+
+
+/* Add new string. The actual string is assumed to be permanent. */
+static Dwelf_Strent *
+strtab_add (Dwelf_Strtab *st, const char *str, size_t len)
+{
+ /* Make sure all "" strings get offset 0 but only if the table was
+ created with a special null entry in mind. */
+ if (len == 1 && st->null.string != NULL)
+ return &st->null;
+
+ /* Allocate memory for the new string and its associated information. */
+ Dwelf_Strent *newstr = newstring (st, str, len);
+ if (newstr == NULL)
+ return NULL;
+
+ /* Search in the array for the place to insert the string. If there
+ is no string with matching prefix and no string with matching
+ leading substring, create a new entry. */
+ Dwelf_Strent **sep = searchstring (&st->root, newstr);
+ if (*sep != newstr)
+ {
+ /* This is not the same entry. This means we have a prefix match. */
+ if ((*sep)->len > newstr->len)
+ {
+ /* Check whether we already know this string. */
+ for (Dwelf_Strent *subs = (*sep)->next; subs != NULL;
+ subs = subs->next)
+ if (subs->len == newstr->len)
+ {
+ /* We have an exact match with a substring. Free the memory
+ we allocated. */
+ st->left += st->backp - (char *) newstr;
+ st->backp = (char *) newstr;
+
+ return subs;
+ }
+
+ /* We have a new substring. This means we don't need the reverse
+ string of this entry anymore. */
+ st->backp -= newstr->len;
+ st->left += newstr->len;
+
+ newstr->next = (*sep)->next;
+ (*sep)->next = newstr;
+ }
+ else if ((*sep)->len != newstr->len)
+ {
+ /* When we get here it means that the string we are about to
+ add has a common prefix with a string we already have but
+ it is longer. In this case we have to put it first. */
+ st->total += newstr->len - (*sep)->len;
+ newstr->next = *sep;
+ newstr->left = (*sep)->left;
+ newstr->right = (*sep)->right;
+ *sep = newstr;
+ }
+ else
+ {
+ /* We have an exact match. Free the memory we allocated. */
+ st->left += st->backp - (char *) newstr;
+ st->backp = (char *) newstr;
+
+ newstr = *sep;
+ }
+ }
+ else
+ st->total += newstr->len;
+
+ return newstr;
+}
+
+Dwelf_Strent *
+dwelf_strtab_add (Dwelf_Strtab *st, const char *str)
+{
+ return strtab_add (st, str, strlen (str) + 1);
+}
+
+Dwelf_Strent *
+dwelf_strtab_add_len (Dwelf_Strtab *st, const char *str, size_t len)
+{
+ return strtab_add (st, str, len);
+}
+
+static void
+copystrings (Dwelf_Strent *nodep, char **freep, size_t *offsetp)
+{
+ if (nodep->left != NULL)
+ copystrings (nodep->left, freep, offsetp);
+
+ /* Process the current node. */
+ nodep->offset = *offsetp;
+ *freep = (char *) mempcpy (*freep, nodep->string, nodep->len);
+ *offsetp += nodep->len;
+
+ for (Dwelf_Strent *subs = nodep->next; subs != NULL; subs = subs->next)
+ {
+ assert (subs->len < nodep->len);
+ subs->offset = nodep->offset + nodep->len - subs->len;
+ assert (subs->offset != 0 || subs->string[0] == '\0');
+ }
+
+ if (nodep->right != NULL)
+ copystrings (nodep->right, freep, offsetp);
+}
+
+
+Elf_Data *
+dwelf_strtab_finalize (Dwelf_Strtab *st, Elf_Data *data)
+{
+ size_t nulllen = st->nullstr ? 1 : 0;
+
+ /* Fill in the information. */
+ data->d_buf = malloc (st->total + nulllen);
+ if (data->d_buf == NULL)
+ return NULL;
+
+ /* The first byte must always be zero if we created the table with a
+ null string. */
+ if (st->nullstr)
+ *((char *) data->d_buf) = '\0';
+
+ data->d_type = ELF_T_BYTE;
+ data->d_size = st->total + nulllen;
+ data->d_off = 0;
+ data->d_align = 1;
+ data->d_version = EV_CURRENT;
+
+ /* Now run through the tree and add all the string while also updating
+ the offset members of the elfstrent records. */
+ char *endp = (char *) data->d_buf + nulllen;
+ size_t copylen = nulllen;
+ if (st->root)
+ copystrings (st->root, &endp, ©len);
+ assert (copylen == st->total + nulllen);
+
+ return data;
+}
+
+
+size_t
+dwelf_strent_off (Dwelf_Strent *se)
+{
+ return se->offset;
+}
+
+
+const char *
+dwelf_strent_str (Dwelf_Strent *se)
+{
+ return se->string;
+}
diff --git a/libdwelf/libdwelf.h b/libdwelf/libdwelf.h
new file mode 100644
index 0000000..72089db
--- /dev/null
+++ b/libdwelf/libdwelf.h
@@ -0,0 +1,132 @@
+/* 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 */
diff --git a/libdwelf/libdwelfP.h b/libdwelf/libdwelfP.h
new file mode 100644
index 0000000..d83c759
--- /dev/null
+++ b/libdwelf/libdwelfP.h
@@ -0,0 +1,42 @@
+/* Internal definitions for libdwelf. DWARF ELF Low-level Functions.
+ Copyright (C) 2014 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 _LIBDWELFP_H
+#define _LIBDWELFP_H 1
+
+#include <libdwelf.h>
+#include "../libdw/libdwP.h" /* We need its INTDECLs. */
+#include <assert.h>
+#include <string.h>
+
+/* Avoid PLT entries. */
+INTDECL (dwelf_elf_gnu_debuglink)
+INTDECL (dwelf_dwarf_gnu_debugaltlink)
+INTDECL (dwelf_elf_gnu_build_id)
+
+#endif /* libdwelfP.h */