aosp12/frameworks/compile/libbcc/lib/RSScreenFunctionsPass.cpp

109 lines
2.6 KiB
C++

/*
* Copyright 2014, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "Log.h"
#include "RSTransforms.h"
#include "RSFunctionsList.h"
#include <cstdlib>
#include <llvm/IR/Instructions.h>
#include <llvm/IR/Module.h>
#include <llvm/IR/Function.h>
#include <llvm/Pass.h>
namespace { // anonymous namespace
// Create a Module pass that screens all the global functions in the
// module and check if any disallowed external function is accessible
// and potentially callable.
class RSScreenFunctionsPass : public llvm::ModulePass {
private:
static char ID;
bool isPresent(const std::string &name) {
auto lower = std::lower_bound(stubList.begin(),
stubList.end(),
name);
if (lower != stubList.end() && name.compare(*lower) == 0)
return true;
return false;
}
bool isLegal(llvm::Function &F) {
// A global function symbol is legal if
// a. it has a body, i.e. is not empty or
// b. its name starts with "llvm." or
// c. it is present in the RS Functions list.
if (!F.empty())
return true;
llvm::StringRef FName = F.getName();
if (FName.startswith("llvm."))
return true;
if (isPresent(FName.str()))
return true;
return false;
}
public:
RSScreenFunctionsPass()
: ModulePass (ID) {
std::sort(stubList.begin(), stubList.end());
}
virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {
AU.setPreservesAll();
}
bool runOnModule(llvm::Module &M) override {
bool failed = false;
auto &FunctionList(M.getFunctionList());
for(auto &F: FunctionList) {
if (!isLegal(F)) {
ALOGE("Call to function %s from RenderScript is disallowed\n",
F.getName().str().c_str());
failed = true;
}
}
if (failed) {
llvm::report_fatal_error("Use of undefined external function");
}
return false;
}
};
}
char RSScreenFunctionsPass::ID = 0;
namespace bcc {
llvm::ModulePass *
createRSScreenFunctionsPass() {
return new RSScreenFunctionsPass();
}
}