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 "llvm/IR/Module.h"
18 #include "llvm/Pass.h"
19 
20 namespace slang {
21 
22 // Remove any readnone/readonly attributes from function parameters,
23 // and remove any argmemonly attributes from functions.
24 //
25 // Jellybean's LLVM version didn't support readnone/readonly as anything
26 // other than function attributes, so it will fail verification otherwise.
27 // Since we never ran the verifier in Jellybean, it ends up with potential
28 // crashes deeper in CodeGen.
29 //
30 // Similarly, older LLVM versions don't support argmemonly as a function
31 // attribute, and so it can trigger an llvm_unreachable assertion when
32 // we attempt to write out bitcode.
33 class StripUnknownAttributes : public llvm::ModulePass {
34 public:
35   static char ID;
36 
37   StripUnknownAttributes();
38 
39   bool runOnFunction(llvm::Function &F);
40 
41   // We have to use a ModulePass, since a FunctionPass only gets run on
42   // defined Functions (and not declared Functions).
43   virtual bool runOnModule(llvm::Module &M);
44 };
45 
46 llvm::ModulePass * createStripUnknownAttributesPass();
47 
48 }  // namespace slang
49