| //===- FileMatchTrie.h ------------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements a match trie to find the matching file in a compilation |
| // database based on a given path in the presence of symlinks. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_TOOLING_FILEMATCHTRIE_H |
| #define LLVM_CLANG_TOOLING_FILEMATCHTRIE_H |
| |
| #include "clang/Basic/LLVM.h" |
| #include "llvm/ADT/StringRef.h" |
| #include <memory> |
| |
| namespace clang { |
| namespace tooling { |
| |
| class FileMatchTrieNode; |
| |
| struct PathComparator { |
| virtual ~PathComparator() = default; |
| |
| virtual bool equivalent(StringRef FileA, StringRef FileB) const = 0; |
| }; |
| |
| /// A trie to efficiently match against the entries of the compilation |
| /// database in order of matching suffix length. |
| /// |
| /// When a clang tool is supposed to operate on a specific file, we have to |
| /// find the corresponding file in the compilation database. Although entries |
| /// in the compilation database are keyed by filename, a simple string match |
| /// is insufficient because of symlinks. Commonly, a project hierarchy looks |
| /// like this: |
| /// /<project-root>/src/<path>/<somefile>.cc (used as input for the tool) |
| /// /<project-root>/build/<symlink-to-src>/<path>/<somefile>.cc (stored in DB) |
| /// |
| /// Furthermore, there might be symlinks inside the source folder or inside the |
| /// database, so that the same source file is translated with different build |
| /// options. |
| /// |
| /// For a given input file, the \c FileMatchTrie finds its entries in order |
| /// of matching suffix length. For each suffix length, there might be one or |
| /// more entries in the database. For each of those entries, it calls |
| /// \c llvm::sys::fs::equivalent() (injected as \c PathComparator). There might |
| /// be zero or more entries with the same matching suffix length that are |
| /// equivalent to the input file. Three cases are distinguished: |
| /// 0 equivalent files: Continue with the next suffix length. |
| /// 1 equivalent file: Best match found, return it. |
| /// >1 equivalent files: Match is ambiguous, return error. |
| class FileMatchTrie { |
| public: |
| FileMatchTrie(); |
| |
| /// Construct a new \c FileMatchTrie with the given \c PathComparator. |
| /// |
| /// The \c FileMatchTrie takes ownership of 'Comparator'. Used for testing. |
| FileMatchTrie(PathComparator* Comparator); |
| |
| ~FileMatchTrie(); |
| |
| /// Insert a new absolute path. Relative paths are ignored. |
| void insert(StringRef NewPath); |
| |
| /// Finds the corresponding file in this trie. |
| /// |
| /// Returns file name stored in this trie that is equivalent to 'FileName' |
| /// according to 'Comparator', if it can be uniquely identified. If there |
| /// are no matches an empty \c StringRef is returned. If there are ambiguous |
| /// matches, an empty \c StringRef is returned and a corresponding message |
| /// written to 'Error'. |
| StringRef findEquivalent(StringRef FileName, |
| raw_ostream &Error) const; |
| |
| private: |
| FileMatchTrieNode *Root; |
| std::unique_ptr<PathComparator> Comparator; |
| }; |
| |
| } // namespace tooling |
| } // namespace clang |
| |
| #endif // LLVM_CLANG_TOOLING_FILEMATCHTRIE_H |