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/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)