1 //===--- CLI.cpp -  ----------------------------------------------*- C++-*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "clang-pseudo/cli/CLI.h"
10 #include "clang-pseudo/cxx/CXX.h"
11 #include "llvm/Support/CommandLine.h"
12 #include "llvm/Support/ErrorOr.h"
13 #include "llvm/Support/MemoryBuffer.h"
14 
15 static llvm::cl::opt<std::string> Grammar(
16     "grammar",
17     llvm::cl::desc(
18         "Specify a BNF grammar file path, or a builtin language (cxx)."),
19     llvm::cl::init("cxx"));
20 
21 namespace clang {
22 namespace pseudo {
23 
24 const Language &getLanguageFromFlags() {
25   if (::Grammar == "cxx")
26     return cxx::getLanguage();
27 
28   static Language *Lang = []() {
29     // Read from a bnf grammar file.
30     llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> GrammarText =
31         llvm::MemoryBuffer::getFile(::Grammar);
32     if (std::error_code EC = GrammarText.getError()) {
33       llvm::errs() << "Error: can't read grammar file '" << ::Grammar
34                    << "': " << EC.message() << "\n";
35       std::exit(1);
36     }
37     std::vector<std::string> Diags;
38     auto G = Grammar::parseBNF(GrammarText->get()->getBuffer(), Diags);
39     for (const auto &Diag : Diags)
40       llvm::errs() << Diag << "\n";
41     auto Table = LRTable::buildSLR(G);
42     return new Language{std::move(G), std::move(Table)};
43   }();
44   return *Lang;
45 }
46 
47 } // namespace pseudo
48 } // namespace clang
49