[WebAssembly] Add throw/rethrow builtins for exception handling

Summary:
Add new builtins for throw/rethrow instructions. This follows exception handling
handling proposal in
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md

Reviewers: sunfish, dschuff

Reviewed By: dschuff

Subscribers: jfb, dschuff, sbc100, jgravelle-google

Differential Revision: https://reviews.llvm.org/D34783

llvm-svn: 306775

1 files changed, 10 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index a6451b7fc3c..2a6e92e7f3c 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -9372,6 +9372,16 @@ Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
     Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_grow_memory, X->getType());
     return Builder.CreateCall(Callee, X);
   }
+  case WebAssembly::BI__builtin_wasm_throw: {
+    Value *Tag = EmitScalarExpr(E->getArg(0));
+    Value *Obj = EmitScalarExpr(E->getArg(1));
+    Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_throw);
+    return Builder.CreateCall(Callee, {Tag, Obj});
+  }
+  case WebAssembly::BI__builtin_wasm_rethrow: {
+    Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_rethrow);
+    return Builder.CreateCall(Callee);
+  }
 
   default:
     return nullptr;