xref: /llvm-project/mlir/examples/toy/Ch1/toyc.cpp (revision 2f20e0ee7331c28af6f84d690df8935d8a4386e6)
1 //===- toyc.cpp - The Toy Compiler ----------------------------------------===//
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 // This file implements the entry point for the Toy compiler.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "toy/AST.h"
14 #include "toy/Lexer.h"
15 #include "toy/Parser.h"
16 
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/Support/ErrorOr.h"
20 #include "llvm/Support/MemoryBuffer.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include <memory>
23 #include <string>
24 #include <system_error>
25 
26 using namespace toy;
27 namespace cl = llvm::cl;
28 
29 static cl::opt<std::string> inputFilename(cl::Positional,
30                                           cl::desc("<input toy file>"),
31                                           cl::init("-"),
32                                           cl::value_desc("filename"));
33 namespace {
34 enum Action { None, DumpAST };
35 } // namespace
36 
37 static cl::opt<enum Action>
38     emitAction("emit", cl::desc("Select the kind of output desired"),
39                cl::values(clEnumValN(DumpAST, "ast", "output the AST dump")));
40 
41 /// Returns a Toy AST resulting from parsing the file or a nullptr on error.
parseInputFile(llvm::StringRef filename)42 std::unique_ptr<toy::ModuleAST> parseInputFile(llvm::StringRef filename) {
43   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> fileOrErr =
44       llvm::MemoryBuffer::getFileOrSTDIN(filename);
45   if (std::error_code ec = fileOrErr.getError()) {
46     llvm::errs() << "Could not open input file: " << ec.message() << "\n";
47     return nullptr;
48   }
49   auto buffer = fileOrErr.get()->getBuffer();
50   LexerBuffer lexer(buffer.begin(), buffer.end(), std::string(filename));
51   Parser parser(lexer);
52   return parser.parseModule();
53 }
54 
main(int argc,char ** argv)55 int main(int argc, char **argv) {
56   cl::ParseCommandLineOptions(argc, argv, "toy compiler\n");
57 
58   auto moduleAST = parseInputFile(inputFilename);
59   if (!moduleAST)
60     return 1;
61 
62   switch (emitAction) {
63   case Action::DumpAST:
64     dump(*moduleAST);
65     return 0;
66   default:
67     llvm::errs() << "No action specified (parsing only?), use -emit=<action>\n";
68   }
69 
70   return 0;
71 }
72