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carbon-lang/executable_semantics/main.cpp
T

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2.7 KiB
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// 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 <unistd.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <vector>
#include "executable_semantics/common/arena.h"
#include "executable_semantics/common/nonnull.h"
#include "executable_semantics/interpreter/exec_program.h"
#include "executable_semantics/syntax/parse.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/InitLLVM.h"
// Adds the Carbon prelude to `declarations`.
static void AddPrelude(
std::string_view prelude_file_name, Carbon::Nonnull<Carbon::Arena*> arena,
std::vector<Carbon::Nonnull<Carbon::Declaration*>>* declarations) {
std::variant<Carbon::AST, Carbon::SyntaxErrorCode> parse_result =
Carbon::Parse(arena, prelude_file_name, false);
if (std::holds_alternative<Carbon::SyntaxErrorCode>(parse_result)) {
// Try again with tracing, to help diagnose the problem.
Carbon::Parse(arena, prelude_file_name, true);
FATAL() << "Failed to parse prelude.";
}
const auto& prelude = std::get<Carbon::AST>(parse_result);
declarations->insert(declarations->begin(), prelude.declarations.begin(),
prelude.declarations.end());
}
auto main(int argc, char* argv[]) -> int {
llvm::setBugReportMsg(
"Please report issues to "
"https://github.com/carbon-language/carbon-lang/issues and include the "
"crash backtrace.\n");
llvm::InitLLVM init_llvm(argc, argv);
// Printing to stderr should flush stdout. This is most noticeable when stderr
// is piped to stdout.
llvm::errs().tie(&llvm::outs());
using llvm::cl::desc;
using llvm::cl::opt;
opt<bool> trace_option("trace", desc("Enable tracing"));
opt<std::string> input_file_name(llvm::cl::Positional, desc("<input file>"),
llvm::cl::Required);
opt<std::string> prelude_file_name(
"prelude", desc("<prelude file>"),
llvm::cl::init("executable_semantics/data/prelude.carbon"));
llvm::cl::ParseCommandLineOptions(argc, argv);
Carbon::Arena arena;
std::variant<Carbon::AST, Carbon::SyntaxErrorCode> ast_or_error =
Carbon::Parse(&arena, input_file_name, trace_option);
if (auto* error = std::get_if<Carbon::SyntaxErrorCode>(&ast_or_error)) {
// Diagnostic already reported to std::cerr; this is just a return code.
return *error;
}
auto& ast = std::get<Carbon::AST>(ast_or_error);
AddPrelude(prelude_file_name, &arena, &ast.declarations);
// Typecheck and run the parsed program.
Carbon::ExecProgram(&arena, std::get<Carbon::AST>(ast_or_error),
trace_option);
}