vendor/gimli/examples/simple.rs

   1 //! A simple example of parsing `.debug_info`.
   2
   3 use object::{Object, ObjectSection};
   4 use std::{borrow, env, fs};
   5
   6 fn main() {
   7     for path in env::args().skip(1) {
   8         let file = fs::File::open(&path).unwrap();
   9         let mmap = unsafe { memmap2::Mmap::map(&file).unwrap() };
  10         let object = object::File::parse(&*mmap).unwrap();
  11         let endian = if object.is_little_endian() {
  12             gimli::RunTimeEndian::Little
  13         } else {
  14             gimli::RunTimeEndian::Big
  15         };
  16         dump_file(&object, endian).unwrap();
  17     }
  18 }
  19
  20 fn dump_file(object: &object::File, endian: gimli::RunTimeEndian) -> Result<(), gimli::Error> {
  21     // Load a section and return as `Cow<[u8]>`.
  22     let load_section = |id: gimli::SectionId| -> Result<borrow::Cow<[u8]>, gimli::Error> {
  23         match object.section_by_name(id.name()) {
  24             Some(ref section) => Ok(section
  25                 .uncompressed_data()
  26                 .unwrap_or(borrow::Cow::Borrowed(&[][..]))),
  27             None => Ok(borrow::Cow::Borrowed(&[][..])),
  28         }
  29     };
  30
  31     // Load all of the sections.
  32     let dwarf_cow = gimli::Dwarf::load(&load_section)?;
  33
  34     // Borrow a `Cow<[u8]>` to create an `EndianSlice`.
  35     let borrow_section: &dyn for<'a> Fn(
  36         &'a borrow::Cow<[u8]>,
  37     ) -> gimli::EndianSlice<'a, gimli::RunTimeEndian> =
  38         &|section| gimli::EndianSlice::new(&*section, endian);
  39
  40     // Create `EndianSlice`s for all of the sections.
  41     let dwarf = dwarf_cow.borrow(&borrow_section);
  42
  43     // Iterate over the compilation units.
  44     let mut iter = dwarf.units();
  45     while let Some(header) = iter.next()? {
  46         println!(
  47             "Unit at <.debug_info+0x{:x}>",
  48             header.offset().as_debug_info_offset().unwrap().0
  49         );
  50         let unit = dwarf.unit(header)?;
  51
  52         // Iterate over the Debugging Information Entries (DIEs) in the unit.
  53         let mut depth = 0;
  54         let mut entries = unit.entries();
  55         while let Some((delta_depth, entry)) = entries.next_dfs()? {
  56             depth += delta_depth;
  57             println!("<{}><{:x}> {}", depth, entry.offset().0, entry.tag());
  58
  59             // Iterate over the attributes in the DIE.
  60             let mut attrs = entry.attrs();
  61             while let Some(attr) = attrs.next()? {
  62                 println!("   {}: {:?}", attr.name(), attr.value());
  63             }
  64         }
  65     }
  66     Ok(())
  67 }