revng-revng/lib/RestructureCFG/ScopeGraphLoggerPass.cpp

//
// This file is distributed under the MIT License. See LICENSE.md for details.
//

#include <fstream>

#include "llvm/IR/Function.h"
#include "llvm/Pass.h"
#include "llvm/Support/ToolOutputFile.h"

#include "revng/RestructureCFG/ScopeGraphGraphTraits.h"
#include "revng/Support/CommandLine.h"

using namespace llvm;

static cl::opt<std::string> OutputPath("scope-graph-output",
                                       cl::desc("Scope Graph serialization "
                                                "path"),
                                       cl::init("-"),
                                       cl::cat(MainCategory),
                                       cl::Optional);

class ScopeGraphLoggerPassImpl {
  llvm::Function &F;

public:
  ScopeGraphLoggerPassImpl(llvm::Function &F) : F(F) {}

public:
  bool run() {
    ExitOnError ExitOnError;
    std::error_code EC;

    llvm::ToolOutputFile OutputFile(OutputPath, EC, llvm::sys::fs::OF_Text);
    revng_assert(!EC, EC.message().c_str());

    OutputFile.os() << dumpScopeGraphImpl(F);
    OutputFile.keep();

    return false; // The function was not modified
  }
};

// We declare this pass directly in the `.cpp` file since we only need it for
// the tests
class ScopeGraphLoggerPass : public llvm::FunctionPass {
public:
  static char ID;

public:
  ScopeGraphLoggerPass() : llvm::FunctionPass(ID) {}

  bool runOnFunction(llvm::Function &F) override;

  void getAnalysisUsage(llvm::AnalysisUsage &AU) const override;
};

char ScopeGraphLoggerPass::ID = 0;

static constexpr const char *Flag = "scope-graph-dumper";
using Reg = llvm::RegisterPass<ScopeGraphLoggerPass>;
static Reg X(Flag, "Dump edge information on the `ScopeGraph`");

bool ScopeGraphLoggerPass::runOnFunction(llvm::Function &F) {

  // Instantiate and call the `Impl` class
  ScopeGraphLoggerPassImpl SGLPImpl(F);
  return SGLPImpl.run();
}

void ScopeGraphLoggerPass::getAnalysisUsage(llvm::AnalysisUsage &AU) const {

  // This is a read only analysis, that does not touch the IR
  AU.setPreservesAll();
}