CArrayIntrospection/FindLengthChecks.cc at master · AlisaMaas/CArrayIntrospection · GitHub

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#define DEBUG_TYPE "find-length"

#include "CallInstSet.hh"
#include "CheckGetElementPtrVisitor.hh"
#include "FindLengthChecks.hh"
#include "IIGlueReader.hh"
#include "SRA/SymbolicRangeAnalysis.h"

#include <boost/algorithm/cxx11/any_of.hpp>
#include <boost/foreach.hpp>
#include <boost/property_tree/json_parser.hpp>
#include <boost/range/adaptor/map.hpp>
#include <boost/range/combine.hpp>
#include <boost/range/irange.hpp>
#include <boost/range/iterator_range.hpp>
#include <fstream>
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#include <llvm/Analysis/LoopPass.h>
#include <llvm/IR/InstVisitor.h>
#include <llvm/IR/Instructions.h>
#include <llvm/IR/Module.h>
#include <llvm/Support/CommandLine.h>
#include <llvm/Support/Debug.h>
#include <llvm/Support/raw_os_ostream.h>

using namespace boost;
using namespace boost::algorithm;
using namespace llvm;
using namespace std;


static const RegisterPass<FindLengthChecks> registration("find-length",
		"Find arrays with a statically known constant or parameter-bounded length.",
		true, true);

char FindLengthChecks::ID;
static llvm::cl::opt<std::string>
    testOutputName("test-find-length",
	llvm::cl::Optional,
	llvm::cl::value_desc("filename"),
	llvm::cl::desc("Filename to write results to for regression tests"));

inline FindLengthChecks::FindLengthChecks()
	: ModulePass(ID) {
}

void FindLengthChecks::getAnalysisUsage(AnalysisUsage &usage) const {
	// read-only pass never changes anything
	usage.setPreservesAll();
	usage.addRequired<IIGlueReader>();
	usage.addRequired<SymbolicRangeAnalysis>();
}


bool FindLengthChecks::runOnModule(Module &module) {
	DEBUG(dbgs() << "Top of runOnModule()\n");
	for (const Function &func : module)
		for (const Argument &arg : make_iterator_range(func.arg_begin(), func.arg_end()))
			valueSets.insert(make_shared<const ValueSet>(ValueSet{&arg}));

	for (Function &func : module) {
		if (func.isDeclaration()) continue;
		DEBUG(dbgs() << "Analyzing " << func.getName() << "\n");
		const SymbolicRangeAnalysis &ra = getAnalysis<SymbolicRangeAnalysis>(func);
		CheckGetElementPtrVisitor visitor{maxIndexes[&func], ra, module, lengths[&func], valueSets};
		for(BasicBlock &visitee :  func) {
			DEBUG(dbgs() << "Visiting a new basic block...\n");
			visitor.visit(visitee);
		}
	}
	if (!testOutputName.empty()) {
		ofstream out(testOutputName);
		llvm::raw_os_ostream sink(out);
		print(sink, &module);
		sink.flush();
		out.close();
	}
	// read-only pass never changes anything
	return false;
}

void FindLengthChecks::print(raw_ostream &sink, const Module *module) const {
	const IIGlueReader &iiglue = getAnalysis<IIGlueReader>();
	for (const Function &func : *module) {
		const auto &constantMap = maxIndexes.at(&func);
		const auto &parameterLengthMap = lengths.at(&func);
		sink << "Analyzing " << func.getName() << "\n";
		for (const Argument &arg : make_iterator_range(func.arg_begin(), func.arg_end())) {
			const auto set = valueSets.getValueSetFromValue(&arg);
			const auto foundConstant = constantMap.find(set);
			if (foundConstant != constantMap.end())
				sink << "\tArgument " << arg.getName() << " has max index " << foundConstant->second << '\n';
			else {
				const auto foundParam = parameterLengthMap.find(set);
				if (foundParam != parameterLengthMap.end())
					sink << "\tArgument " << arg.getName() << " has max index argument " << (*foundParam->second->begin())->getName() << '\n';
				else if (iiglue.isArray(arg))
					sink << "\tArgument " << arg.getName() << " has unknown max index.\n";
			}
		}
	}

}