llvm-capstone/llvm/unittests/IR/CFGBuilder.h
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

94 lines
2.4 KiB
C++

//===- CFGBuilder.h - CFG building and updating utility ----------*- C++ -*-==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// CFGBuilders provides utilities fo building and updating CFG for testing
/// purposes.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_UNITTESTS_CFG_BUILDER_H
#define LLVM_UNITTESTS_CFG_BUILDER_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Debug.h"
#include <memory>
#include <set>
#include <tuple>
#include <vector>
namespace llvm {
class LLVMContext;
class Module;
class Function;
class BasicBlock;
class raw_ostream;
struct CFGHolder {
std::unique_ptr<LLVMContext> Context;
std::unique_ptr<Module> M;
Function *F;
CFGHolder(StringRef ModuleName = "m", StringRef FunctionName = "foo");
~CFGHolder(); // Defined in the .cpp file so we can use forward declarations.
};
/// \brief
/// CFGBuilder builds IR with specific CFG, based on the supplied list of arcs.
/// It's able to apply the provided updates and automatically modify the IR.
///
/// Internally it makes every basic block end with either SwitchInst or with
/// UnreachableInst. When all arc to a BB are deleted, the BB remains in the
/// function and doesn't get deleted.
///
class CFGBuilder {
public:
struct Arc {
StringRef From;
StringRef To;
friend bool operator<(const Arc &LHS, const Arc &RHS) {
return std::tie(LHS.From, LHS.To) <
std::tie(RHS.From, RHS.To);
}
};
enum class ActionKind { Insert, Delete };
struct Update {
ActionKind Action;
Arc Edge;
};
CFGBuilder(Function *F, const std::vector<Arc> &InitialArcs,
std::vector<Update> Updates);
BasicBlock *getOrAddBlock(StringRef BlockName);
Optional<Update> getNextUpdate() const;
Optional<Update> applyUpdate();
void dump(raw_ostream &OS = dbgs()) const;
private:
void buildCFG(const std::vector<Arc> &Arcs);
bool connect(const Arc &A);
bool disconnect(const Arc &A);
Function *F;
unsigned UpdateIdx = 0;
StringMap<BasicBlock *> NameToBlock;
std::set<Arc> Arcs;
std::vector<Update> Updates;
};
} // namespace llvm
#endif