Vendor things

third-party/vendor/addr2line/src/builtin_split_dwarf_loader.rs

@@ -0,0 +1,164 @@
+use alloc::borrow::Cow;
+use alloc::sync::Arc;
+use std::fs::File;
+use std::path::PathBuf;
+
+use object::Object;
+
+use crate::{LookupContinuation, LookupResult};
+
+#[cfg(unix)]
+fn convert_path<R: gimli::Reader<Endian = gimli::RunTimeEndian>>(
+    r: &R,
+) -> Result<PathBuf, gimli::Error> {
+    use std::ffi::OsStr;
+    use std::os::unix::ffi::OsStrExt;
+    let bytes = r.to_slice()?;
+    let s = OsStr::from_bytes(&bytes);
+    Ok(PathBuf::from(s))
+}
+
+#[cfg(not(unix))]
+fn convert_path<R: gimli::Reader<Endian = gimli::RunTimeEndian>>(
+    r: &R,
+) -> Result<PathBuf, gimli::Error> {
+    let bytes = r.to_slice()?;
+    let s = std::str::from_utf8(&bytes).map_err(|_| gimli::Error::BadUtf8)?;
+    Ok(PathBuf::from(s))
+}
+
+fn load_section<'data: 'file, 'file, O, R, F>(
+    id: gimli::SectionId,
+    file: &'file O,
+    endian: R::Endian,
+    loader: &mut F,
+) -> Result<R, gimli::Error>
+where
+    O: object::Object<'data, 'file>,
+    R: gimli::Reader<Endian = gimli::RunTimeEndian>,
+    F: FnMut(Cow<'data, [u8]>, R::Endian) -> R,
+{
+    use object::ObjectSection;
+
+    let data = id
+        .dwo_name()
+        .and_then(|dwo_name| {
+            file.section_by_name(dwo_name)
+                .and_then(|section| section.uncompressed_data().ok())
+        })
+        .unwrap_or(Cow::Borrowed(&[]));
+    Ok(loader(data, endian))
+}
+
+/// A simple builtin split DWARF loader.
+pub struct SplitDwarfLoader<R, F>
+where
+    R: gimli::Reader<Endian = gimli::RunTimeEndian>,
+    F: FnMut(Cow<'_, [u8]>, R::Endian) -> R,
+{
+    loader: F,
+    dwarf_package: Option<gimli::DwarfPackage<R>>,
+}
+
+impl<R, F> SplitDwarfLoader<R, F>
+where
+    R: gimli::Reader<Endian = gimli::RunTimeEndian>,
+    F: FnMut(Cow<'_, [u8]>, R::Endian) -> R,
+{
+    fn load_dwarf_package(loader: &mut F, path: Option<PathBuf>) -> Option<gimli::DwarfPackage<R>> {
+        let mut path = path.map(Ok).unwrap_or_else(std::env::current_exe).ok()?;
+        let dwp_extension = path
+            .extension()
+            .map(|previous_extension| {
+                let mut previous_extension = previous_extension.to_os_string();
+                previous_extension.push(".dwp");
+                previous_extension
+            })
+            .unwrap_or_else(|| "dwp".into());
+        path.set_extension(dwp_extension);
+        let file = File::open(&path).ok()?;
+        let map = unsafe { memmap2::Mmap::map(&file).ok()? };
+        let dwp = object::File::parse(&*map).ok()?;
+
+        let endian = if dwp.is_little_endian() {
+            gimli::RunTimeEndian::Little
+        } else {
+            gimli::RunTimeEndian::Big
+        };
+
+        let empty = loader(Cow::Borrowed(&[]), endian);
+        gimli::DwarfPackage::load(
+            |section_id| load_section(section_id, &dwp, endian, loader),
+            empty,
+        )
+        .ok()
+    }
+
+    /// Create a new split DWARF loader.
+    pub fn new(mut loader: F, path: Option<PathBuf>) -> SplitDwarfLoader<R, F> {
+        let dwarf_package = SplitDwarfLoader::load_dwarf_package(&mut loader, path);
+        SplitDwarfLoader {
+            loader,
+            dwarf_package,
+        }
+    }
+
+    /// Run the provided `LookupResult` to completion, loading any necessary
+    /// split DWARF along the way.
+    pub fn run<L>(&mut self, mut l: LookupResult<L>) -> L::Output
+    where
+        L: LookupContinuation<Buf = R>,
+    {
+        loop {
+            let (load, continuation) = match l {
+                LookupResult::Output(output) => break output,
+                LookupResult::Load { load, continuation } => (load, continuation),
+            };
+
+            let mut r: Option<Arc<gimli::Dwarf<_>>> = None;
+            if let Some(dwp) = self.dwarf_package.as_ref() {
+                if let Ok(Some(cu)) = dwp.find_cu(load.dwo_id, &load.parent) {
+                    r = Some(Arc::new(cu));
+                }
+            }
+
+            if r.is_none() {
+                let mut path = PathBuf::new();
+                if let Some(p) = load.comp_dir.as_ref() {
+                    if let Ok(p) = convert_path(p) {
+                        path.push(p);
+                    }
+                }
+
+                if let Some(p) = load.path.as_ref() {
+                    if let Ok(p) = convert_path(p) {
+                        path.push(p);
+                    }
+                }
+
+                if let Ok(file) = File::open(&path) {
+                    if let Ok(map) = unsafe { memmap2::Mmap::map(&file) } {
+                        if let Ok(file) = object::File::parse(&*map) {
+                            let endian = if file.is_little_endian() {
+                                gimli::RunTimeEndian::Little
+                            } else {
+                                gimli::RunTimeEndian::Big
+                            };
+
+                            r = gimli::Dwarf::load(|id| {
+                                load_section(id, &file, endian, &mut self.loader)
+                            })
+                            .ok()
+                            .map(|mut dwo_dwarf| {
+                                dwo_dwarf.make_dwo(&load.parent);
+                                Arc::new(dwo_dwarf)
+                            });
+                        }
+                    }
+                }
+            }
+
+            l = continuation.resume(r);
+        }
+    }
+}