1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
| //===-- BrainFDriver.cpp - BrainF compiler driver -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt 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 prog.bf #Run program now
// ./BrainF -jit -abc prog.bf #Run program now safely
// ./BrainF prog.bf #Write as BitCode
//
// lli prog.bf.bc #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(
Type::getInt32Ty(mod->getContext()),
{Type::getInt32Ty(mod->getContext()),
Type::getInt8Ty(mod->getContext())->getPointerTo()->getPointerTo()},
false);
Function *main_func =
Function::Create(main_func_fty, Function::ExternalLinkage, "main", mod);
{
Function::arg_iterator args = main_func->arg_begin();
Value *arg_0 = &*args++;
arg_0->setName("argc");
Value *arg_1 = &*args++;
arg_1->setName("argv");
}
//main.0:
BasicBlock *bb = BasicBlock::Create(mod->getContext(), "main.0", main_func);
//call void @brainf()
{
CallInst *brainf_call = CallInst::Create(mod->getFunction("brainf"),
"", bb);
brainf_call->setTailCall(false);
}
//ret i32 0
ReturnInst::Create(mod->getContext(),
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";
abort();
}
//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;
addMainFunction(Mod.get());
//Verify generated code
if (verifyModule(*Mod)) {
errs() << "Error: module failed verification. This shouldn't happen.\n";
abort();
}
//Write it out
if (JIT) {
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
outs() << "------- Running JIT -------\n";
Module &M = *Mod;
ExecutionEngine *ee = EngineBuilder(std::move(Mod)).create();
if (!ee) {
errs() << "Error: execution engine creation failed.\n";
abort();
}
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.
fflush(stdout);
} else {
WriteBitcodeToFile(*Mod, *out);
}
//Clean up
if (out != &outs())
delete out;
llvm_shutdown();
return 0;
}
|