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//===--- PathRemapper.h - Transforms path prefixes --------------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file defines a data structure that stores a string-to-string
// mapping used to transform file paths based on a prefix mapping. It
// is optimized for the common case, which is that there will be
// extremely few mappings (i.e., one or two).
//
// Remappings are stored such that they are applied in the order they
// are passed on the command line. This would only matter if one
// source mapping was a prefix of another.
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_BASIC_PATHREMAPPER_H
#define SWIFT_BASIC_PATHREMAPPER_H
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Twine.h"
#include <string>
#include <utility>
namespace swift {
class PathRemapper {
SmallVector<std::pair<std::string, std::string>, 2> PathMappings;
public:
/// Adds a mapping such that any paths starting with `FromPrefix` have that
/// portion replaced with `ToPrefix`.
void addMapping(StringRef FromPrefix, StringRef ToPrefix) {
PathMappings.emplace_back(FromPrefix.str(), ToPrefix.str());
}
/// Returns a remapped `Path` if it starts with a prefix in the map; otherwise
/// the original path is returned.
std::string remapPath(StringRef Path) const {
// Clang's implementation of this feature also compares the path string
// directly instead of treating path segments as indivisible units. The
// latter would arguably be more accurate, but we choose to preserve
// compatibility with Clang (especially because we propagate the flag to
// ClangImporter as well).
for (const auto &Mapping : PathMappings)
if (Path.startswith(Mapping.first))
return (Twine(Mapping.second) +
Path.substr(Mapping.first.size())).str();
return Path.str();
}
};
} // end namespace swift
#endif // SWIFT_BASIC_PATHREMAPPER_H