aboutsummaryrefslogtreecommitdiff
path: root/examples/BrainF/BrainFDriver.cpp
blob: 58617b7f38092e6b11a3827920c9fd50e35c0893 (plain)
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
//===-- BrainFDriver.cpp - BrainF compiler driver -----------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===--------------------------------------------------------------------===//
//
// 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/Constants.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/ExecutionEngine/JIT.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include <iostream>
#include <fstream>
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)
  Function *main_func = cast<Function>(mod->
    getOrInsertFunction("main", IntegerType::getInt32Ty(mod->getContext()),
                        IntegerType::getInt32Ty(mod->getContext()),
                        PointerType::getUnqual(PointerType::getUnqual(
                          IntegerType::getInt8Ty(mod->getContext()))), NULL));
  {
    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 = getGlobalContext();

  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::string ErrInfo;
      out = new raw_fd_ostream(OutputFilename.c_str(), ErrInfo,
                               raw_fd_ostream::F_Binary);
    }
  }

  //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;
  Module *mod = bf.parse(in, 65536, cf, Context); //64 KiB
  if (in != &std::cin)
    delete in;
  addMainFunction(mod);

  //Verify generated code
  if (verifyModule(*mod)) {
    errs() << "Error: module failed verification.  This shouldn't happen.\n";
    abort();
  }

  //Write it out
  if (JIT) {
    InitializeNativeTarget();

    outs() << "------- Running JIT -------\n";
    ExecutionEngine *ee = EngineBuilder(mod).create();
    std::vector<GenericValue> args;
    Function *brainf_func = mod->getFunction("brainf");
    GenericValue gv = ee->runFunction(brainf_func, args);
  } else {
    WriteBitcodeToFile(mod, *out);
  }

  //Clean up
  if (out != &outs())
    delete out;
  delete mod;

  llvm_shutdown();

  return 0;
}