1//===-- WebAssemblyCleanCodeAfterTrap.cpp - Clean Code After Trap ---------===//
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/// This file remove instruction after trap.
11/// ``llvm.trap`` will be convert as ``unreachable`` which is terminator.
12/// Instruction after terminator will cause validation failed.
13///
14//===----------------------------------------------------------------------===//
15
16#include "WebAssembly.h"
17#include "WebAssemblyUtilities.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
20#include "llvm/CodeGen/Passes.h"
21#include "llvm/MC/MCInstrDesc.h"
22#include "llvm/Support/Debug.h"
23#include "llvm/Support/raw_ostream.h"
24using namespace llvm;
25
26#define DEBUG_TYPE "wasm-clean-code-after-trap"
27
28namespace {
29class WebAssemblyCleanCodeAfterTrap final : public MachineFunctionPass {
30public:
31 static char ID; // Pass identification, replacement for typeid
32 WebAssemblyCleanCodeAfterTrap() : MachineFunctionPass(ID) {}
33
34 StringRef getPassName() const override {
35 return "WebAssembly Clean Code After Trap";
36 }
37
38 bool runOnMachineFunction(MachineFunction &MF) override;
39};
40} // end anonymous namespace
41
42char WebAssemblyCleanCodeAfterTrap::ID = 0;
43INITIALIZE_PASS(WebAssemblyCleanCodeAfterTrap, DEBUG_TYPE,
44 "WebAssembly Clean Code After Trap", false, false)
45
46FunctionPass *llvm::createWebAssemblyCleanCodeAfterTrap() {
47 return new WebAssemblyCleanCodeAfterTrap();
48}
49
50bool WebAssemblyCleanCodeAfterTrap::runOnMachineFunction(MachineFunction &MF) {
51 LLVM_DEBUG({
52 dbgs() << "********** CleanCodeAfterTrap **********\n"
53 << "********** Function: " << MF.getName() << '\n';
54 });
55
56 bool Changed = false;
57
58 for (MachineBasicBlock &BB : MF) {
59 bool HasTerminator = false;
60 llvm::SmallVector<MachineInstr *> RemoveMI{};
61 for (MachineInstr &MI : BB) {
62 if (HasTerminator)
63 RemoveMI.push_back(Elt: &MI);
64 if (MI.hasProperty(MCFlag: MCID::Trap) && MI.isTerminator())
65 HasTerminator = true;
66 }
67 if (!RemoveMI.empty()) {
68 Changed = true;
69 LLVM_DEBUG({
70 for (MachineInstr *MI : RemoveMI) {
71 llvm::dbgs() << "* remove ";
72 MI->print(llvm::dbgs());
73 }
74 });
75 for (MachineInstr *MI : RemoveMI)
76 MI->eraseFromParent();
77 }
78 }
79 return Changed;
80}
81