[WebAssembly] Allow multivalue signatures in object files

Summary:
Also changes the wasm YAML format to reflect the possibility of having
multiple return types and to put the returns after the params for
consistency with the binary encoding.

Reviewers: aheejin, sbc100

Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, arphaman, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69156

llvm-svn: 375283

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 470283efb29..014b403556d 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -881,12 +881,9 @@ Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) {
       Sig.Params.push_back(wasm::ValType(ParamType));
     }
     uint32_t ReturnCount = readVaruint32(Ctx);
-    if (ReturnCount) {
-      if (ReturnCount != 1) {
-        return make_error<GenericBinaryError>(
-            "Multiple return types not supported", object_error::parse_failed);
-      }
-      Sig.Returns.push_back(wasm::ValType(readUint8(Ctx)));
+    while (ReturnCount--) {
+      uint32_t ReturnType = readUint8(Ctx);
+      Sig.Returns.push_back(wasm::ValType(ReturnType));
     }
     Signatures.push_back(std::move(Sig));
   }