Files
carbon-lang/executable_semantics/syntax/parse.cpp
T
Jon MeowandChandler Carruth f0af3cb795 Switch from llvm::errs()+exit() to FATAL_USER_ERROR() stream-based handling. (#670)
This is intended to:

- Standardize use of line_num (and highlight where no line_num is available).
- Standardize indications of runtime/compilation errors.
- Make it incrementally easier to write new errors.

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2021-07-28 10:47:33 -07:00

48 lines
1.4 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "executable_semantics/syntax/parse.h"
#include <iostream>
#include "common/check.h"
#include "executable_semantics/common/error.h"
#include "executable_semantics/common/tracing_flag.h"
#include "executable_semantics/syntax/parse_and_lex_context.h"
#include "executable_semantics/syntax/parser.h"
extern FILE* yyin;
namespace Carbon {
// Returns an abstract representation of the program contained in the
// well-formed input file, or if the file was malformed, a description of the
// problem.
auto parse(const std::string& input_file_name)
-> std::variant<AST, SyntaxErrorCode> {
yyin = fopen(input_file_name.c_str(), "r");
if (yyin == nullptr) {
FATAL_USER_ERROR_NO_LINE() << "Error opening '" << input_file_name
<< "': " << std::strerror(errno);
}
std::optional<AST> parsed_input = std::nullopt;
ParseAndLexContext context(input_file_name);
auto parser = yy::parser(parsed_input, context);
if (tracing_output) {
parser.set_debug_level(1);
}
auto syntax_error_code = parser();
if (syntax_error_code != 0) {
return syntax_error_code;
}
CHECK(parsed_input != std::nullopt)
<< "parser validated syntax yet didn't produce an AST.";
return *parsed_input;
}
} // namespace Carbon