1/*
2 * Copyright 2017, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "strip_unknown_attributes.h"
18
19#include "llvm/IR/Function.h"
20
21namespace slang {
22
23bool stripUnknownAttributes(llvm::Function &F) {
24  bool changed = false;
25  for (llvm::Function::arg_iterator I = F.arg_begin(), E = F.arg_end();
26       I != E; ++I) {
27    llvm::Argument &A = *I;
28    // Remove any readnone/readonly attributes from function parameters.
29    if (A.onlyReadsMemory()) {
30      llvm::AttrBuilder B;
31      B.addAttribute(llvm::Attribute::ReadNone);
32      B.addAttribute(llvm::Attribute::ReadOnly);
33      llvm::AttributeSet ToStrip = llvm::AttributeSet::get(F.getContext(),
34          A.getArgNo() + 1, B);
35      A.removeAttr(ToStrip);
36      changed = true;
37    }
38  }
39  F.removeFnAttr(llvm::Attribute::ArgMemOnly);
40  return changed;
41}
42
43}  // namespace slang
44