Export rust_eh_unwind_resume symbol

Author: Amanieu

src/librustc_codegen_ssa/back/symbol_export.rs

@@ -182,6 +182,12 @@ fn exported_symbols_provider_local(
         symbols.push((exported_symbol, SymbolExportLevel::C));
     }
 
+    if tcx.is_panic_runtime(LOCAL_CRATE) && tcx.sess.target.target.options.custom_unwind_resume {
+        let exported_symbol = ExportedSymbol::NoDefId(SymbolName::new("rust_eh_unwind_resume"));
+
+        symbols.push((exported_symbol, SymbolExportLevel::Rust));
+    }
+
     if tcx.allocator_kind().is_some() {
         for method in ALLOCATOR_METHODS {
             let symbol_name = format!("__rust_{}", method.name);

src/librustc_codegen_ssa/mir/block.rs

@@ -178,15 +178,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             let lp1 = bx.load_operand(lp1).immediate();
             slot.storage_dead(&mut bx);
 
-            if !bx.sess().target.target.options.custom_unwind_resume {
-                let mut lp = bx.const_undef(self.landing_pad_type());
-                lp = bx.insert_value(lp, lp0, 0);
-                lp = bx.insert_value(lp, lp1, 1);
-                bx.resume(lp);
-            } else {
-                bx.call(bx.eh_unwind_resume(), &[lp0], helper.funclet(self));
-                bx.unreachable();
-            }
+            let mut lp = bx.const_undef(self.landing_pad_type());
+            lp = bx.insert_value(lp, lp0, 0);
+            lp = bx.insert_value(lp, lp1, 1);
+            bx.resume(lp);
         }
     }
 

src/librustc_target/spec/windows_base.rs

@@ -64,7 +64,7 @@ pub fn opts() -> TargetOptions {
         ],
         late_link_args,
         post_link_objects: vec!["rsend.o".to_string()],
-        custom_unwind_resume: false,
+        custom_unwind_resume: true,
         abi_return_struct_as_int: true,
         emit_debug_gdb_scripts: false,
         requires_uwtable: true,