rustc_codegen_ssa: take the handlers directly in catch_switch.

Author: eddyb

compiler/rustc_codegen_llvm/src/builder.rs

@@ -997,25 +997,25 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         &mut self,
         parent: Option<&'ll Value>,
         unwind: Option<&'ll BasicBlock>,
-        num_handlers: usize,
+        handlers: &[&'ll BasicBlock],
     ) -> &'ll Value {
         let name = cstr!("catchswitch");
         let ret = unsafe {
             llvm::LLVMRustBuildCatchSwitch(
                 self.llbuilder,
                 parent,
                 unwind,
-                num_handlers as c_uint,
+                handlers.len() as c_uint,
                 name.as_ptr(),
             )
         };
-        ret.expect("LLVM does not have support for catchswitch")
-    }
-
-    fn add_handler(&mut self, catch_switch: &'ll Value, handler: &'ll BasicBlock) {
-        unsafe {
-            llvm::LLVMRustAddHandler(catch_switch, handler);
+        let catch_switch = ret.expect("LLVM does not have support for catchswitch");
+        for &handler in handlers {
+            unsafe {
+                llvm::LLVMRustAddHandler(catch_switch, handler);
+            }
         }
+        catch_switch
     }
 
     fn set_personality_fn(&mut self, personality: &'ll Value) {

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -465,9 +465,8 @@ fn codegen_msvc_try(
 
         normal.ret(bx.const_i32(0));
 
-        let cs = catchswitch.catch_switch(None, None, 2);
-        catchswitch.add_handler(cs, catchpad_rust.llbb());
-        catchswitch.add_handler(cs, catchpad_foreign.llbb());
+        let cs =
+            catchswitch.catch_switch(None, None, &[catchpad_rust.llbb(), catchpad_foreign.llbb()]);
 
         // We can't use the TypeDescriptor defined in libpanic_unwind because it
         // might be in another DLL and the SEH encoding only supports specifying

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -317,8 +317,7 @@ fn create_funclets<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
                     let mut cp_bx = bx.build_sibling_block(&format!("cp_funclet{:?}", bb));
                     ret_llbb = cs_bx.llbb();
 
-                    let cs = cs_bx.catch_switch(None, None, 1);
-                    cs_bx.add_handler(cs, cp_bx.llbb());
+                    let cs = cs_bx.catch_switch(None, None, &[cp_bx.llbb()]);
 
                     // The "null" here is actually a RTTI type descriptor for the
                     // C++ personality function, but `catch (...)` has no type so

compiler/rustc_codegen_ssa/src/traits/builder.rs

@@ -253,9 +253,8 @@ pub trait BuilderMethods<'a, 'tcx>:
         &mut self,
         parent: Option<Self::Value>,
         unwind: Option<Self::BasicBlock>,
-        num_handlers: usize,
+        handlers: &[Self::BasicBlock],
     ) -> Self::Value;
-    fn add_handler(&mut self, catch_switch: Self::Value, handler: Self::BasicBlock);
     fn set_personality_fn(&mut self, personality: Self::Value);
 
     fn atomic_cmpxchg(