blob: 64483479692362e0b716583333fef8d9c5d168bb [file] [log] [blame]
//===-- BrainFDriver.cpp - BrainF compiler driver -------------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This program converts the BrainF language into LLVM assembly,
// which it can then run using the JIT or output as BitCode.
// This implementation has a tape of 65536 bytes,
// with the head starting in the middle.
// Range checking is off by default, so be careful.
// It can be enabled with -abc.
// Use:
// ./BrainF -jit #Run program now
// ./BrainF -jit -abc #Run program now safely
// ./BrainF #Write as BitCode
// lli #Run generated BitCode
#include "BrainF.h"
#include "llvm/ADT/APInt.h"
#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/ExecutionEngine/MCJIT.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <memory>
#include <string>
#include <system_error>
#include <vector>
using namespace llvm;
//Command line options
static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input brainf>"));
static cl::opt<std::string>
OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
static cl::opt<bool>
ArrayBoundsChecking("abc", cl::desc("Enable array bounds checking"));
static cl::opt<bool>
JIT("jit", cl::desc("Run program Just-In-Time"));
//Add main function so can be fully compiled
void addMainFunction(Module *mod) {
//define i32 @main(i32 %argc, i8 **%argv)
FunctionType *main_func_fty = FunctionType::get(
Function *main_func =
Function::Create(main_func_fty, Function::ExternalLinkage, "main", mod);
Function::arg_iterator args = main_func->arg_begin();
Value *arg_0 = &*args++;
Value *arg_1 = &*args++;
BasicBlock *bb = BasicBlock::Create(mod->getContext(), "main.0", main_func);
//call void @brainf()
CallInst *brainf_call = CallInst::Create(mod->getFunction("brainf"),
"", bb);
//ret i32 0
ConstantInt::get(mod->getContext(), APInt(32, 0)), bb);
int main(int argc, char **argv) {
cl::ParseCommandLineOptions(argc, argv, " BrainF compiler\n");
LLVMContext Context;
if (InputFilename == "") {
errs() << "Error: You must specify the filename of the program to "
"be compiled. Use --help to see the options.\n";
//Get the output stream
raw_ostream *out = &outs();
if (!JIT) {
if (OutputFilename == "") {
std::string base = InputFilename;
if (InputFilename == "-") { base = "a"; }
// Use default filename.
OutputFilename = base+".bc";
if (OutputFilename != "-") {
std::error_code EC;
out = new raw_fd_ostream(OutputFilename, EC, sys::fs::OF_None);
//Get the input stream
std::istream *in = &std::cin;
if (InputFilename != "-")
in = new std::ifstream(InputFilename.c_str());
//Gather the compile flags
BrainF::CompileFlags cf = BrainF::flag_off;
if (ArrayBoundsChecking)
cf = BrainF::CompileFlags(cf | BrainF::flag_arraybounds);
//Read the BrainF program
BrainF bf;
std::unique_ptr<Module> Mod(bf.parse(in, 65536, cf, Context)); // 64 KiB
if (in != &std::cin)
delete in;
//Verify generated code
if (verifyModule(*Mod)) {
errs() << "Error: module failed verification. This shouldn't happen.\n";
//Write it out
if (JIT) {
outs() << "------- Running JIT -------\n";
Module &M = *Mod;
ExecutionEngine *ee = EngineBuilder(std::move(Mod)).create();
if (!ee) {
errs() << "Error: execution engine creation failed.\n";
std::vector<GenericValue> args;
Function *brainf_func = M.getFunction("brainf");
GenericValue gv = ee->runFunction(brainf_func, args);
// Genereated code calls putchar, and output is not guaranteed without fflush.
// The better place for fflush(stdout) call would be the generated code, but it
// is unmanageable because stdout linkage name depends on stdlib implementation.
} else {
WriteBitcodeToFile(*Mod, *out);
//Clean up
if (out != &outs())
delete out;
return 0;