refactor: Move some ELF-specific dynamic allocation code (#1728)

Issue #1538

Author: davidlattimore

libwild/src/elf.rs

@@ -460,6 +460,21 @@ impl platform::Platform for Elf {
             .sum::<usize>(), "resolved relocations");
     }
 
+    fn activate_dynamic<'data>(
+        state: &mut layout::DynamicLayoutState<'data, Self>,
+        common: &mut CommonGroupState<'data, Self>,
+    ) {
+        common.allocate(
+            part_id::DYNAMIC,
+            size_of::<crate::elf::DynamicEntry>() as u64,
+        );
+
+        common.allocate(part_id::DYNSTR, state.lib_name.len() as u64 + 1);
+
+        state.format_specific_state.symbol_versions_needed =
+            vec![false; state.object.verdefnum as usize];
+    }
+
     fn pre_finalise_sizes_prelude<'scope, 'data>(
         prelude: &mut layout::PreludeLayoutState<'data, Self>,
         common: &mut layout::CommonGroupState<'data, Self>,
@@ -2164,10 +2179,6 @@ impl<'data> platform::ObjectFile<'data> for File<'data> {
         Ok(())
     }
 
-    fn activate_dynamic(&self, state: &mut DynamicLayoutStateExt<'data>) {
-        state.symbol_versions_needed = vec![false; self.verdefnum as usize];
-    }
-
     fn finalise_sizes_dynamic(
         &self,
         lib_name: &[u8],

libwild/src/layout.rs

@@ -1076,7 +1076,7 @@ pub(crate) struct DynamicLayoutState<'data, P: Platform> {
     input: InputRef<'data>,
     file_id: FileId,
     pub(crate) symbol_id_range: SymbolIdRange,
-    lib_name: &'data [u8],
+    pub(crate) lib_name: &'data [u8],
 
     pub(crate) format_specific_state: P::DynamicLayoutStateExt<'data>,
 }
@@ -4554,15 +4554,7 @@ impl<'data, P: Platform> DynamicLayoutState<'data, P> {
         queue: &mut LocalWorkQueue,
         scope: &Scope<'scope>,
     ) -> Result {
-        self.object
-            .activate_dynamic(&mut self.format_specific_state);
-
-        common.allocate(
-            part_id::DYNAMIC,
-            size_of::<crate::elf::DynamicEntry>() as u64,
-        );
-
-        common.allocate(part_id::DYNSTR, self.lib_name.len() as u64 + 1);
+        P::activate_dynamic(self, common);
 
         self.request_all_undefined_symbols::<A>(resources, queue, scope)
     }

libwild/src/platform.rs

@@ -284,6 +284,13 @@ pub(crate) trait Platform: Copy + Send + Sync + Sized + std::fmt::Debug + 'stati
     /// Called after GC phase has completed. Mostly useful for platform-specific logging.
     fn finalise_find_required_sections(groups: &[layout::GroupState<Self>]);
 
+    /// The dynamic object will be linked against. This is a chance to perform extra initialisation
+    /// of `state`.
+    fn activate_dynamic<'data>(
+        state: &mut layout::DynamicLayoutState<'data, Self>,
+        common: &mut CommonGroupState<'data, Self>,
+    );
+
     fn pre_finalise_sizes_prelude<'scope, 'data>(
         prelude: &mut layout::PreludeLayoutState<'data, Self>,
         common: &mut layout::CommonGroupState<'data, Self>,
@@ -663,13 +670,6 @@ pub(crate) trait ObjectFile<'data>: Sized + Send + Sync + std::fmt::Debug + 'dat
 
     fn symbol_versions(&self) -> &[<Self::Platform as Platform>::SymbolVersionIndex];
 
-    /// The dynamic object will be linked against. This is a chance to perform extra initialisation
-    /// of `state`.
-    fn activate_dynamic(
-        &self,
-        state: &mut <Self::Platform as Platform>::DynamicLayoutStateExt<'data>,
-    );
-
     fn dynamic_symbol_used(
         &self,
         symbol_index: object::SymbolIndex,