libdwarf: compile locally if not present

Change-Id: I70d1f653f4fc4ee4daeaa2c9c6bdbf1416e43c9b

cmake/modules/FindLibElf.cmake

@@ -0,0 +1,64 @@
+# - Try to find libelf
+# Once done this will define
+#
+#  LIBELF_FOUND - system has libelf
+#  LIBELF_INCLUDE_DIRS - the libelf include directory
+#  LIBELF_LIBRARIES - Link these to use libelf
+#  LIBELF_DEFINITIONS - Compiler switches required for using libelf
+#
+# This module reads hints about search locations from variables:
+#
+#  LIBELF_ROOT - Preferred installation prefix
+#
+#  Copyright (c) 2008 Bernhard Walle <bernhard.walle@gmx.de>
+#
+#  Redistribution and use is allowed according to the terms of the New
+#  BSD license.
+#  For details see the accompanying COPYING-CMAKE-SCRIPTS file.
+#
+
+
+if (LIBELF_LIBRARIES AND LIBELF_INCLUDE_DIRS)
+  set (LibElf_FIND_QUIETLY TRUE)
+endif (LIBELF_LIBRARIES AND LIBELF_INCLUDE_DIRS)
+
+find_path (LIBELF_INCLUDE_DIRS
+  NAMES
+    libelf/libelf.h libelf.h
+  HINTS
+    ${LIBELF_ROOT}
+  PATH_SUFFIXES
+    include
+	libelf/include
+)
+
+find_library (LIBELF_LIBRARIES
+  NAMES
+    elf libelf
+  HINTS
+    ${LIBELF_ROOT}
+  PATH_SUFFIXES
+    lib
+	libelf/lib
+)
+
+include (FindPackageHandleStandardArgs)
+
+
+# handle the QUIETLY and REQUIRED arguments and set LIBELF_FOUND to TRUE if all listed variables are TRUE
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(LibElf DEFAULT_MSG
+  LIBELF_LIBRARIES
+  LIBELF_INCLUDE_DIRS)
+
+set(CMAKE_REQUIRED_LIBRARIES elf)
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles("#include <libelf.h>
+int main() {
+  Elf *e = (Elf*)0;
+  size_t sz;
+  elf_getshdrstrndx(e, &sz);
+  return 0;
+}" ELF_GETSHDRSTRNDX)
+unset(CMAKE_REQUIRED_LIBRARIES)
+
+mark_as_advanced(LIBELF_INCLUDE_DIRS LIBELF_LIBRARIES ELF_GETSHDRSTRNDX)