Tell LLVM to not mangle names if they're already mangled through link_name attribute

3 files changed, 4 insertions, 39 deletions

diff --git a/src/codegen/helpers.rs b/src/codegen/helpers.rs
index 5136d787..9a8b0576 100644
--- a/src/codegen/helpers.rs
+++ b/src/codegen/helpers.rs
@@ -45,6 +45,9 @@ pub mod attributes {
     }
 
     pub fn link_name(name: &str) -> quote::Tokens {
+        // LLVM mangles the name by default but it's already mangled.
+        // Prefixing the name with \u{1} should tell LLVM to not mangle it.
+        let name = format!("\u{1}{}", name);
         quote! {
             #[link_name = #name]
         }
diff --git a/src/ir/context.rs b/src/ir/context.rs
index 8f361094..c84e66ca 100644
--- a/src/ir/context.rs
+++ b/src/ir/context.rs
@@ -391,9 +391,6 @@ pub struct BindgenContext {
     /// bitfield allocation units computed. Drained in `compute_bitfield_units`.
     need_bitfield_allocation: Vec<ItemId>,
 
-    /// Whether we need the mangling hack which removes the prefixing underscore.
-    needs_mangling_hack: bool,
-
     /// The set of (`ItemId`s of) types that can't derive debug.
     ///
     /// This is populated when we enter codegen by `compute_cannot_derive_debug`
@@ -558,15 +555,6 @@ impl BindgenContext {
             ).expect("TranslationUnit::parse failed")
         };
 
-        // Mac os, iOS and Win32 need __ for mangled symbols but rust will
-        // automatically prepend the extra _.
-        //
-        // We need to make sure that we don't include __ because rust will turn
-        // into ___.
-        let needs_mangling_hack = effective_target.contains("darwin") ||
-            effective_target.contains("ios") ||
-            effective_target == "i686-pc-win32";
-
         let root_module = Self::build_root_module(ItemId(0));
         let root_module_id = root_module.id().as_module_id_unchecked();
 
@@ -592,7 +580,6 @@ impl BindgenContext {
             codegen_items: None,
             used_template_parameters: None,
             need_bitfield_allocation: Default::default(),
-            needs_mangling_hack: needs_mangling_hack,
             cannot_derive_debug: None,
             cannot_derive_default: None,
             cannot_derive_copy: None,
@@ -1415,11 +1402,6 @@ impl BindgenContext {
         Item::new(id, None, None, id, ItemKind::Module(module))
     }
 
-    /// Returns the target triple bindgen is running over.
-    pub fn needs_mangling_hack(&self) -> bool {
-        self.needs_mangling_hack
-    }
-
     /// Get the root module.
     pub fn root_module(&self) -> ModuleId {
         self.root_module
diff --git a/src/ir/function.rs b/src/ir/function.rs
index 3a9f337c..b637f9f1 100644
--- a/src/ir/function.rs
+++ b/src/ir/function.rs
@@ -206,23 +206,6 @@ fn get_abi(cc: CXCallingConv) -> Abi {
     }
 }
 
-fn mangling_hack_if_needed(ctx: &BindgenContext, symbol: &mut String) {
-    if ctx.needs_mangling_hack() {
-        match symbol.chars().next().unwrap() {
-            // Stripping leading underscore for all names on Darwin and
-            // C linkage functions on Win32.
-            '_' => {
-                symbol.remove(0);
-            }
-            // Stop Rust from prepending underscore for variables on Win32.
-            '?' => {
-                symbol.insert(0, '\x01');
-            }
-            _ => {}
-        }
-    }
-}
-
 /// Get the mangled name for the cursor's referent.
 pub fn cursor_mangling(
     ctx: &BindgenContext,
@@ -241,8 +224,7 @@ pub fn cursor_mangling(
     }
 
     if let Ok(mut manglings) = cursor.cxx_manglings() {
-        if let Some(mut m) = manglings.pop() {
-            mangling_hack_if_needed(ctx, &mut m);
+        if let Some(m) = manglings.pop() {
             return Some(m);
         }
     }
@@ -252,8 +234,6 @@ pub fn cursor_mangling(
         return None;
     }
 
-    mangling_hack_if_needed(ctx, &mut mangling);
-
     if cursor.kind() == clang_sys::CXCursor_Destructor {
         // With old (3.8-) libclang versions, and the Itanium ABI, clang returns
         // the "destructor group 0" symbol, which means that it'll try to free