LegacyPassNameParser.h

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//===- LegacyPassNameParser.h -----------------------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file contains the PassNameParser and FilteredPassNameParser<> classes,
// which are used to add command line arguments to a utility for all of the
// passes that have been registered into the system.
//
// The PassNameParser class adds ALL passes linked into the system (that are
// creatable) as command line arguments to the tool (when instantiated with the
// appropriate command line option template).  The FilteredPassNameParser<>
// template is used for the same purposes as PassNameParser, except that it only
// includes passes that have a PassType that are compatible with the filter
// (which is the template argument).
//
// Note that this is part of the legacy pass manager infrastructure and will be
// (eventually) going away.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_LEGACYPASSNAMEPARSER_H
#define LLVM_IR_LEGACYPASSNAMEPARSER_H

#include "llvm/ADT/STLExtras.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cstring>

namespace llvm {

//===----------------------------------------------------------------------===//
// PassNameParser class - Make use of the pass registration mechanism to
// automatically add a command line argument to opt for each pass.
//
class PassNameParser : public PassRegistrationListener,
                       public cl::parser<const PassInfo*> {
public:
  PassNameParser(cl::Option &O);
  ~PassNameParser() override;

  void initialize() {
    cl::parser<const PassInfo*>::initialize();

    // Add all of the passes to the map that got initialized before 'this' did.
    enumeratePasses();
  }

  // ignorablePassImpl - Can be overriden in subclasses to refine the list of
  // which passes we want to include.
  //
  virtual bool ignorablePassImpl(const PassInfo *P) const { return false; }

  inline bool ignorablePass(const PassInfo *P) const {
    // Ignore non-selectable and non-constructible passes!  Ignore
    // non-optimizations.
    return P->getPassArgument().empty() || P->getNormalCtor() == nullptr ||
           ignorablePassImpl(P);
  }

  // Implement the PassRegistrationListener callbacks used to populate our map
  //
  void passRegistered(const PassInfo *P) override {
    if (ignorablePass(P)) return;
    if (findOption(P->getPassArgument().data()) != getNumOptions()) {
      errs() << "Two passes with the same argument (-"
           << P->getPassArgument() << ") attempted to be registered!\n";
      llvm_unreachable(nullptr);
    }
    addLiteralOption(P->getPassArgument().data(), P, P->getPassName().data());
  }
  void passEnumerate(const PassInfo *P) override { passRegistered(P); }

  // printOptionInfo - Print out information about this option.  Override the
  // default implementation to sort the table before we print...
  void printOptionInfo(const cl::Option &O, size_t GlobalWidth) const override {
    PassNameParser *PNP = const_cast<PassNameParser*>(this);
    array_pod_sort(PNP->Values.begin(), PNP->Values.end(), ValCompare);
    cl::parser<const PassInfo*>::printOptionInfo(O, GlobalWidth);
  }

private:
  // ValCompare - Provide a sorting comparator for Values elements...
  static int ValCompare(const PassNameParser::OptionInfo *VT1,
                        const PassNameParser::OptionInfo *VT2) {
    return VT1->Name.compare(VT2->Name);
  }
};

///===----------------------------------------------------------------------===//
/// FilteredPassNameParser class - Make use of the pass registration
/// mechanism to automatically add a command line argument to opt for
/// each pass that satisfies a filter criteria.  Filter should return
/// true for passes to be registered as command-line options.
///
template<typename Filter>
class FilteredPassNameParser : public PassNameParser {
private:
  Filter filter;

public:
  bool ignorablePassImpl(const PassInfo *P) const override {
    return !filter(*P);
  }
};

///===----------------------------------------------------------------------===//
/// PassArgFilter - A filter for use with PassNameFilterParser that only
/// accepts a Pass whose Arg matches certain strings.
///
/// Use like this:
///
/// extern const char AllowedPassArgs[] = "-anders_aa -dse";
///
/// static cl::list<
///   const PassInfo*,
///   bool,
///   FilteredPassNameParser<PassArgFilter<AllowedPassArgs> > >
/// PassList(cl::desc("Passes available:"));
///
/// Only the -anders_aa and -dse options will be available to the user.
///
template<const char *Args>
class PassArgFilter {
public:
  bool operator()(const PassInfo &P) const {
    return StringRef(Args).contains(P.getPassArgument());
  }
};

} // End llvm namespace

#endif