| // rust-linemap.h -- interface to location tracking -*- C++ -*- |
| |
| // Copyright 2011 The Go Authors. All rights reserved. |
| // Copyright (C) 2020-2024 Free Software Foundation, Inc. |
| |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the '../go/gofrontend/LICENSE' file. |
| |
| #ifndef RUST_LINEMAP_H |
| #define RUST_LINEMAP_H |
| |
| #include "rust-system.h" |
| |
| // The backend must define a type named Location which holds |
| // information about a location in a source file. The only thing the |
| // frontend does with instances of Location is pass them back to the |
| // backend interface. The Location type must be assignable, and it |
| // must be comparable: i.e., it must support operator= and operator<. |
| // The type is normally passed by value rather than by reference, and |
| // it should support that efficiently. The type should be defined in |
| // "rust-location.h". |
| #include "rust-location.h" |
| |
| // The Linemap class is a pure abstract interface, plus some static |
| // convenience functions. The backend must implement the interface. |
| |
| /* TODO: probably better to replace linemap implementation as pure abstract |
| * interface with some sort of compile-time switch (macros or maybe templates if |
| * doable without too much extra annoyance) as to the definition of the methods |
| * or whatever. This is to improve performance, as virtual function calls would |
| * otherwise have to be made in tight loops like in the lexer. */ |
| |
| class Linemap |
| { |
| public: |
| Linemap () : in_file_ (false) |
| { |
| // Only one instance of Linemap is allowed to exist. |
| rust_assert (Linemap::instance_ == NULL); |
| Linemap::instance_ = this; |
| } |
| |
| ~Linemap () { Linemap::instance_ = NULL; } |
| |
| // Subsequent Location values will come from the file named |
| // FILE_NAME, starting at LINE_BEGIN. Normally LINE_BEGIN will be |
| // 0, but it will be non-zero if the Rust source has a //line comment. |
| void start_file (const char *file_name, unsigned int line_begin); |
| |
| // Stop generating Location values. This will be called after all |
| // input files have been read, in case any cleanup is required. |
| void stop (); |
| |
| protected: |
| // The single existing instance of Linemap. |
| static Linemap *instance_; |
| |
| public: |
| // Following are convenience static functions, which allow us to |
| // access some virtual functions without explicitly passing around |
| // an instance of Linemap. |
| |
| // Produce a human-readable description of a Location, e.g. |
| // "foo.rust:10". Returns an empty string for predeclared, builtin or |
| // unknown locations. |
| static std::string location_to_string (location_t loc); |
| |
| private: |
| // Whether we are currently reading a file. |
| bool in_file_; |
| }; |
| |
| #endif // !defined(RUST_LINEMAP_H) |