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 "clang-pseudo/grammar/Grammar.h"
12 #include "llvm/Support/CommandLine.h"
13 #include "llvm/Support/ErrorOr.h"
14 #include "llvm/Support/MemoryBuffer.h"
15 
16 static llvm::cl::opt<std::string> Grammar(
17     "grammar",
18     llvm::cl::desc(
19         "Specify a BNF grammar file path, or a builtin language (cxx)."),
20     llvm::cl::init("cxx"));
21 
22 namespace clang {
23 namespace pseudo {
24 
25 const Language &getLanguageFromFlags() {
26   if (::Grammar == "cxx")
27     return cxx::getLanguage();
28 
29   static Language *Lang = []() {
30     // Read from a bnf grammar file.
31     llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> GrammarText =
32         llvm::MemoryBuffer::getFile(::Grammar);
33     if (std::error_code EC = GrammarText.getError()) {
34       llvm::errs() << "Error: can't read grammar file '" << ::Grammar
35                    << "': " << EC.message() << "\n";
36       std::exit(1);
37     }
38     std::vector<std::string> Diags;
39     auto G = Grammar::parseBNF(GrammarText->get()->getBuffer(), Diags);
40     for (const auto &Diag : Diags)
41       llvm::errs() << Diag << "\n";
42     auto Table = LRTable::buildSLR(G);
43     return new Language{
44         std::move(G),
45         std::move(Table),
46         llvm::DenseMap<ExtensionID, RuleGuard>(),
47         llvm::DenseMap<ExtensionID, RecoveryStrategy>(),
48     };
49   }();
50   return *Lang;
51 }
52 
53 } // namespace pseudo
54 } // namespace clang
55