1//=== WebAssemblyNullifyDebugValueLists.cpp - Nullify DBG_VALUE_LISTs ---===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// Nullify DBG_VALUE_LISTs instructions as a temporary measure before we
11/// implement DBG_VALUE_LIST handling in WebAssemblyDebugValueManager.
12/// See https://github.com/llvm/llvm-project/issues/49705.
13/// TODO Correctly handle DBG_VALUE_LISTs
14///
15//===----------------------------------------------------------------------===//
16
17#include "WebAssembly.h"
18#include "WebAssemblySubtarget.h"
19#include "llvm/CodeGen/MachineFunctionPass.h"
20using namespace llvm;
21
22#define DEBUG_TYPE "wasm-nullify-dbg-value-lists"
23
24namespace {
25class WebAssemblyNullifyDebugValueLists final : public MachineFunctionPass {
26 StringRef getPassName() const override {
27 return "WebAssembly Nullify DBG_VALUE_LISTs";
28 }
29
30 bool runOnMachineFunction(MachineFunction &MF) override;
31
32public:
33 static char ID; // Pass identification, replacement for typeid
34 WebAssemblyNullifyDebugValueLists() : MachineFunctionPass(ID) {}
35};
36} // end anonymous namespace
37
38char WebAssemblyNullifyDebugValueLists::ID = 0;
39INITIALIZE_PASS(WebAssemblyNullifyDebugValueLists, DEBUG_TYPE,
40 "WebAssembly Nullify DBG_VALUE_LISTs", false, false)
41
42FunctionPass *llvm::createWebAssemblyNullifyDebugValueLists() {
43 return new WebAssemblyNullifyDebugValueLists();
44}
45
46bool WebAssemblyNullifyDebugValueLists::runOnMachineFunction(
47 MachineFunction &MF) {
48 LLVM_DEBUG(dbgs() << "********** Nullify DBG_VALUE_LISTs **********\n"
49 "********** Function: "
50 << MF.getName() << '\n');
51 bool Changed = false;
52 // Our backend, including WebAssemblyDebugValueManager, currently cannot
53 // handle DBG_VALUE_LISTs correctly. So this makes them undefined, which will
54 // appear as "optimized out".
55 for (auto &MBB : MF) {
56 for (auto &MI : MBB) {
57 if (MI.getOpcode() == TargetOpcode::DBG_VALUE_LIST) {
58 MI.setDebugValueUndef();
59 Changed = true;
60 }
61 }
62 }
63 return Changed;
64}
65