[WebAssembly] Do not emit tail calls with return type mismatch
Summary:
return_call and return_call_indirect are only valid if the return
types of the callee and caller match. We were previously not enforcing
that, which was producing invalid modules.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65246
llvm-svn: 367339
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
index d9089de..26baac3 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -226,6 +226,17 @@
if (WebAssembly::isCallIndirect(MI->getOpcode()))
Params.pop_back();
+ // return_call_indirect instructions have the return type of the
+ // caller
+ if (MI->getOpcode() == WebAssembly::RET_CALL_INDIRECT) {
+ const Function &F = MI->getMF()->getFunction();
+ const TargetMachine &TM = MI->getMF()->getTarget();
+ Type *RetTy = F.getReturnType();
+ SmallVector<MVT, 4> CallerRetTys;
+ computeLegalValueVTs(F, TM, RetTy, CallerRetTys);
+ valTypesFromMVTs(CallerRetTys, Returns);
+ }
+
auto *WasmSym = cast<MCSymbolWasm>(Sym);
auto Signature = make_unique<wasm::WasmSignature>(std::move(Returns),
std::move(Params));