1 /*
2 * Copyright 2013, 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 namespace slang {
20
StripUnknownAttributes()21 StripUnknownAttributes::StripUnknownAttributes() : ModulePass(ID) {
22 }
23
24
runOnFunction(llvm::Function & F)25 bool StripUnknownAttributes::runOnFunction(llvm::Function &F) {
26 bool changed = false;
27 for (llvm::Function::arg_iterator I = F.arg_begin(), E = F.arg_end();
28 I != E; ++I) {
29 llvm::Argument &A = *I;
30 // Remove any readnone/readonly attributes from function parameters.
31 if (A.onlyReadsMemory()) {
32 llvm::AttrBuilder B;
33 B.addAttribute(llvm::Attribute::ReadNone);
34 B.addAttribute(llvm::Attribute::ReadOnly);
35 llvm::AttributeSet ToStrip = llvm::AttributeSet::get(F.getContext(),
36 A.getArgNo() + 1, B);
37 A.removeAttr(ToStrip);
38 changed = true;
39 }
40 }
41 return changed;
42 }
43
44
runOnModule(llvm::Module & M)45 bool StripUnknownAttributes::runOnModule(llvm::Module &M) {
46 bool Changed = false;
47 for (llvm::Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
48 Changed |= runOnFunction(*I);
49 }
50 return Changed;
51 }
52
53
createStripUnknownAttributesPass()54 llvm::ModulePass * createStripUnknownAttributesPass() {
55 return new StripUnknownAttributes();
56 }
57
58
59 char StripUnknownAttributes::ID = 0;
60 static llvm::RegisterPass<StripUnknownAttributes> RPSUA(
61 "StripUnknownAttributes", "Strip Unknown Attributes Pass");
62
63 } // namespace slang
64