Merge pull request #292 from philipc/issue-10

Break up lib.rs

src/frame.rs

@@ -0,0 +1,220 @@
+use alloc::borrow::Cow;
+use alloc::string::String;
+use core::iter;
+
+use crate::{maybe_small, Error, Function, InlinedFunction, ResUnit};
+
+/// A source location.
+pub struct Location<'a> {
+    /// The file name.
+    pub file: Option<&'a str>,
+    /// The line number.
+    pub line: Option<u32>,
+    /// The column number.
+    ///
+    /// A value of `Some(0)` indicates the left edge.
+    pub column: Option<u32>,
+}
+
+/// A function frame.
+pub struct Frame<'ctx, R: gimli::Reader> {
+    /// The DWARF unit offset corresponding to the DIE of the function.
+    pub dw_die_offset: Option<gimli::UnitOffset<R::Offset>>,
+    /// The name of the function.
+    pub function: Option<FunctionName<R>>,
+    /// The source location corresponding to this frame.
+    pub location: Option<Location<'ctx>>,
+}
+
+/// An iterator over function frames.
+pub struct FrameIter<'ctx, R>(FrameIterState<'ctx, R>)
+where
+    R: gimli::Reader;
+
+enum FrameIterState<'ctx, R>
+where
+    R: gimli::Reader,
+{
+    Empty,
+    Location(Option<Location<'ctx>>),
+    Frames(FrameIterFrames<'ctx, R>),
+}
+
+struct FrameIterFrames<'ctx, R>
+where
+    R: gimli::Reader,
+{
+    unit: &'ctx ResUnit<R>,
+    sections: &'ctx gimli::Dwarf<R>,
+    function: &'ctx Function<R>,
+    inlined_functions: iter::Rev<maybe_small::IntoIter<&'ctx InlinedFunction<R>>>,
+    next: Option<Location<'ctx>>,
+}
+
+impl<'ctx, R> FrameIter<'ctx, R>
+where
+    R: gimli::Reader + 'ctx,
+{
+    pub(crate) fn new_empty() -> Self {
+        FrameIter(FrameIterState::Empty)
+    }
+
+    pub(crate) fn new_location(location: Location<'ctx>) -> Self {
+        FrameIter(FrameIterState::Location(Some(location)))
+    }
+
+    pub(crate) fn new_frames(
+        unit: &'ctx ResUnit<R>,
+        sections: &'ctx gimli::Dwarf<R>,
+        function: &'ctx Function<R>,
+        inlined_functions: maybe_small::Vec<&'ctx InlinedFunction<R>>,
+        location: Option<Location<'ctx>>,
+    ) -> Self {
+        FrameIter(FrameIterState::Frames(FrameIterFrames {
+            unit,
+            sections,
+            function,
+            inlined_functions: inlined_functions.into_iter().rev(),
+            next: location,
+        }))
+    }
+
+    /// Advances the iterator and returns the next frame.
+    pub fn next(&mut self) -> Result<Option<Frame<'ctx, R>>, Error> {
+        let frames = match &mut self.0 {
+            FrameIterState::Empty => return Ok(None),
+            FrameIterState::Location(location) => {
+                // We can't move out of a mutable reference, so use `take` instead.
+                let location = location.take();
+                self.0 = FrameIterState::Empty;
+                return Ok(Some(Frame {
+                    dw_die_offset: None,
+                    function: None,
+                    location,
+                }));
+            }
+            FrameIterState::Frames(frames) => frames,
+        };
+
+        let loc = frames.next.take();
+        let func = match frames.inlined_functions.next() {
+            Some(func) => func,
+            None => {
+                let frame = Frame {
+                    dw_die_offset: Some(frames.function.dw_die_offset),
+                    function: frames.function.name.clone().map(|name| FunctionName {
+                        name,
+                        language: frames.unit.lang,
+                    }),
+                    location: loc,
+                };
+                self.0 = FrameIterState::Empty;
+                return Ok(Some(frame));
+            }
+        };
+
+        let mut next = Location {
+            file: None,
+            line: if func.call_line != 0 {
+                Some(func.call_line)
+            } else {
+                None
+            },
+            column: if func.call_column != 0 {
+                Some(func.call_column)
+            } else {
+                None
+            },
+        };
+        if let Some(call_file) = func.call_file {
+            if let Some(lines) = frames.unit.parse_lines(frames.sections)? {
+                next.file = lines.file(call_file);
+            }
+        }
+        frames.next = Some(next);
+
+        Ok(Some(Frame {
+            dw_die_offset: Some(func.dw_die_offset),
+            function: func.name.clone().map(|name| FunctionName {
+                name,
+                language: frames.unit.lang,
+            }),
+            location: loc,
+        }))
+    }
+}
+
+#[cfg(feature = "fallible-iterator")]
+impl<'ctx, R> fallible_iterator::FallibleIterator for FrameIter<'ctx, R>
+where
+    R: gimli::Reader + 'ctx,
+{
+    type Item = Frame<'ctx, R>;
+    type Error = Error;
+
+    #[inline]
+    fn next(&mut self) -> Result<Option<Frame<'ctx, R>>, Error> {
+        self.next()
+    }
+}
+
+/// A function name.
+pub struct FunctionName<R: gimli::Reader> {
+    /// The name of the function.
+    pub name: R,
+    /// The language of the compilation unit containing this function.
+    pub language: Option<gimli::DwLang>,
+}
+
+impl<R: gimli::Reader> FunctionName<R> {
+    /// The raw name of this function before demangling.
+    pub fn raw_name(&self) -> Result<Cow<'_, str>, Error> {
+        self.name.to_string_lossy()
+    }
+
+    /// The name of this function after demangling (if applicable).
+    pub fn demangle(&self) -> Result<Cow<'_, str>, Error> {
+        self.raw_name().map(|x| demangle_auto(x, self.language))
+    }
+}
+
+/// Demangle a symbol name using the demangling scheme for the given language.
+///
+/// Returns `None` if demangling failed or is not required.
+#[allow(unused_variables)]
+pub fn demangle(name: &str, language: gimli::DwLang) -> Option<String> {
+    match language {
+        #[cfg(feature = "rustc-demangle")]
+        gimli::DW_LANG_Rust => rustc_demangle::try_demangle(name)
+            .ok()
+            .as_ref()
+            .map(|x| format!("{:#}", x)),
+        #[cfg(feature = "cpp_demangle")]
+        gimli::DW_LANG_C_plus_plus
+        | gimli::DW_LANG_C_plus_plus_03
+        | gimli::DW_LANG_C_plus_plus_11
+        | gimli::DW_LANG_C_plus_plus_14 => cpp_demangle::Symbol::new(name)
+            .ok()
+            .and_then(|x| x.demangle(&Default::default()).ok()),
+        _ => None,
+    }
+}
+
+/// Apply 'best effort' demangling of a symbol name.
+///
+/// If `language` is given, then only the demangling scheme for that language
+/// is used.
+///
+/// If `language` is `None`, then heuristics are used to determine how to
+/// demangle the name. Currently, these heuristics are very basic.
+///
+/// If demangling fails or is not required, then `name` is returned unchanged.
+pub fn demangle_auto(name: Cow<'_, str>, language: Option<gimli::DwLang>) -> Cow<'_, str> {
+    match language {
+        Some(language) => demangle(name.as_ref(), language),
+        None => demangle(name.as_ref(), gimli::DW_LANG_Rust)
+            .or_else(|| demangle(name.as_ref(), gimli::DW_LANG_C_plus_plus)),
+    }
+    .map(Cow::from)
+    .unwrap_or(name)
+}

src/function.rs

@@ -1,7 +1,6 @@
 use alloc::boxed::Box;
 use alloc::vec::Vec;
 use core::cmp::Ordering;
-use core::iter;
 
 use crate::lazy::LazyCell;
 use crate::maybe_small;
@@ -316,7 +315,7 @@ impl<R: gimli::Reader> Function<R> {
     pub(crate) fn find_inlined_functions(
         &self,
         probe: u64,
-    ) -> iter::Rev<maybe_small::IntoIter<&InlinedFunction<R>>> {
+    ) -> maybe_small::Vec<&InlinedFunction<R>> {
         // `inlined_functions` is ordered from outside to inside.
         let mut inlined_functions = maybe_small::Vec::new();
         let mut inlined_addresses = &self.inlined_addresses[..];
@@ -347,7 +346,7 @@ impl<R: gimli::Reader> Function<R> {
                 break;
             }
         }
-        inlined_functions.into_iter().rev()
+        inlined_functions
     }
 }