[WebAssembly] Refactor WasmSignature and use it for MCSymbolWasm

MCContext does not destroy MCSymbols on shutdown. So, rather than putting
SmallVectors (which may heap-allocate) inside MCSymbolWasm, use unowned pointer
to a WasmSignature instead. The signatures are now owned by the AsmPrinter.
Also uses WasmSignature instead of param and result vectors in TargetStreamer,
and leaves some TODOs for further simplification.

 Differential Revision: https://reviews.llvm.org/D52580

llvm-svn: 343733

1 files changed, 4 insertions, 5 deletions

diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 711b415552a..75925a5ea10 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -701,17 +701,16 @@ Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) {
   Signatures.reserve(Count);
   while (Count--) {
     wasm::WasmSignature Sig;
-    Sig.ReturnType = wasm::WASM_TYPE_NORESULT;
     uint8_t Form = readUint8(Ctx);
     if (Form != wasm::WASM_TYPE_FUNC) {
       return make_error<GenericBinaryError>("Invalid signature type",
                                             object_error::parse_failed);
     }
     uint32_t ParamCount = readVaruint32(Ctx);
-    Sig.ParamTypes.reserve(ParamCount);
+    Sig.Params.reserve(ParamCount);
     while (ParamCount--) {
       uint32_t ParamType = readUint8(Ctx);
-      Sig.ParamTypes.push_back(ParamType);
+      Sig.Params.push_back(wasm::ValType(ParamType));
     }
     uint32_t ReturnCount = readVaruint32(Ctx);
     if (ReturnCount) {
@@ -719,9 +718,9 @@ Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) {
         return make_error<GenericBinaryError>(
             "Multiple return types not supported", object_error::parse_failed);
       }
-      Sig.ReturnType = readUint8(Ctx);
+      Sig.Returns.push_back(wasm::ValType(readUint8(Ctx)));
     }
-    Signatures.push_back(Sig);
+    Signatures.push_back(std::move(Sig));
   }
   if (Ctx.Ptr != Ctx.End)
     return make_error<GenericBinaryError>("Type section ended prematurely",