read/macho: split object names in ObjectMap (#686)

Author: philipc

crates/examples/src/bin/objectmap.rs

@@ -57,11 +57,16 @@ fn main() {
 }
 
 fn print_symbol(symbol: &object::ObjectMapEntry<'_>, map: &object::ObjectMap<'_>) {
-    println!(
+    let file = symbol.object(map);
+    print!(
         "{:x} {:x} {} {}",
         symbol.address(),
         symbol.size(),
         String::from_utf8_lossy(symbol.name()),
-        String::from_utf8_lossy(symbol.object(map)),
+        String::from_utf8_lossy(file.path()),
     );
+    if let Some(member) = file.member() {
+        print!("({})", String::from_utf8_lossy(member));
+    }
+    println!();
 }

src/read/macho/symbol.rs

@@ -7,9 +7,9 @@ use crate::macho;
 use crate::pod::Pod;
 use crate::read::util::StringTable;
 use crate::read::{
-    self, ObjectMap, ObjectMapEntry, ObjectSymbol, ObjectSymbolTable, ReadError, ReadRef, Result,
-    SectionIndex, SectionKind, SymbolFlags, SymbolIndex, SymbolKind, SymbolMap, SymbolMapEntry,
-    SymbolScope, SymbolSection,
+    self, ObjectMap, ObjectMapEntry, ObjectMapFile, ObjectSymbol, ObjectSymbolTable, ReadError,
+    ReadRef, Result, SectionIndex, SectionKind, SymbolFlags, SymbolIndex, SymbolKind, SymbolMap,
+    SymbolMapEntry, SymbolScope, SymbolSection,
 };
 
 use super::{MachHeader, MachOFile};
@@ -115,7 +115,20 @@ impl<'data, Mach: MachHeader, R: ReadRef<'data>> SymbolTable<'data, Mach, R> {
                     if let Ok(name) = nlist.name(endian, self.strings) {
                         if !name.is_empty() {
                             object = Some(objects.len());
-                            objects.push(name);
+                            // `N_OSO` symbol names can be either `/path/to/object.o`
+                            // or `/path/to/archive.a(object.o)`.
+                            let (path, member) = name
+                                .split_last()
+                                .and_then(|(last, head)| {
+                                    if *last != b')' {
+                                        return None;
+                                    }
+                                    let index = head.iter().position(|&x| x == b'(')?;
+                                    let (archive, rest) = head.split_at(index);
+                                    Some((archive, Some(&rest[1..])))
+                                })
+                                .unwrap_or((name, None));
+                            objects.push(ObjectMapFile::new(path, member));
                         }
                     }
                 }

src/read/mod.rs

@@ -512,7 +512,7 @@ impl<'data> SymbolMapEntry for SymbolMapName<'data> {
 #[derive(Debug, Default, Clone)]
 pub struct ObjectMap<'data> {
     symbols: SymbolMap<ObjectMapEntry<'data>>,
-    objects: Vec<&'data [u8]>,
+    objects: Vec<ObjectMapFile<'data>>,
 }
 
 impl<'data> ObjectMap<'data> {
@@ -531,12 +531,12 @@ impl<'data> ObjectMap<'data> {
 
     /// Get all objects in the map.
     #[inline]
-    pub fn objects(&self) -> &[&'data [u8]] {
+    pub fn objects(&self) -> &[ObjectMapFile<'data>] {
         &self.objects
     }
 }
 
-/// An [`ObjectMap`] entry.
+/// A symbol in an [`ObjectMap`].
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ObjectMapEntry<'data> {
     address: u64,
@@ -574,8 +574,8 @@ impl<'data> ObjectMapEntry<'data> {
 
     /// Get the object file name.
     #[inline]
-    pub fn object(&self, map: &ObjectMap<'data>) -> &'data [u8] {
-        map.objects[self.object]
+    pub fn object<'a>(&self, map: &'a ObjectMap<'data>) -> &'a ObjectMapFile<'data> {
+        &map.objects[self.object]
     }
 }
 
@@ -586,6 +586,31 @@ impl<'data> SymbolMapEntry for ObjectMapEntry<'data> {
     }
 }
 
+/// An object file name in an [`ObjectMap`].
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct ObjectMapFile<'data> {
+    path: &'data [u8],
+    member: Option<&'data [u8]>,
+}
+
+impl<'data> ObjectMapFile<'data> {
+    fn new(path: &'data [u8], member: Option<&'data [u8]>) -> Self {
+        ObjectMapFile { path, member }
+    }
+
+    /// Get the path to the file containing the object.
+    #[inline]
+    pub fn path(&self) -> &'data [u8] {
+        self.path
+    }
+
+    /// If the file is an archive, get the name of the member containing the object.
+    #[inline]
+    pub fn member(&self) -> Option<&'data [u8]> {
+        self.member
+    }
+}
+
 /// An imported symbol.
 ///
 /// Returned by [`Object::imports`].