| # clang pseudoparser |
| |
| This directory implements an approximate heuristic parser for C++, based on the |
| clang lexer, the C++ grammar, and the GLR parsing algorithm. |
| |
| It parses a file in isolation, without reading its included headers. |
| The result is a strict syntactic tree whose structure follows the C++ grammar. |
| There is no semantic analysis, apart from guesses to disambiguate the parse. |
| Disambiguation can optionally be guided by an AST or a symbol index. |
| |
| For now, the best reference on intended scope is the [design proposal], |
| with further discussion on the [RFC]. |
| |
| ## Dependencies between pseudoparser and clang |
| |
| Dependencies are limited because they don't make sense, but also to avoid |
| placing a burden on clang mantainers. |
| |
| The pseudoparser reuses the clang lexer (clangLex and clangBasic libraries) but |
| not the higher-level libraries (Parse, Sema, AST, Frontend...). |
| |
| When the pseudoparser should be used together with an AST (e.g. to guide |
| disambiguation), this is a separate "bridge" library that depends on both. |
| |
| Clang does not depend on the pseudoparser at all. If this seems useful in future |
| it should be discussed by RFC. |
| |
| ## Parity between pseudoparser and clang |
| |
| The pseudoparser aims to understand real-world code, and particularly the |
| languages and extensions supported by Clang. |
| |
| However we don't try to keep these in lockstep: there's no expectation that |
| Clang parser changes are accompanied by pseudoparser changes or vice versa. |
| |
| [design proposal]: https://docs.google.com/document/d/1eGkTOsFja63wsv8v0vd5JdoTonj-NlN3ujGF0T7xDbM/edit |
| [RFC]: https://discourse.llvm.org/t/rfc-a-c-pseudo-parser-for-tooling/59217/49 |
