1 //===-- BrainFDriver.cpp - BrainF compiler driver -----------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===--------------------------------------------------------------------===//
10 // This program converts the BrainF language into LLVM assembly,
11 // which it can then run using the JIT or output as BitCode.
13 // This implementation has a tape of 65536 bytes,
14 // with the head starting in the middle.
15 // Range checking is off by default, so be careful.
16 // It can be enabled with -abc.
19 // ./BrainF -jit prog.bf #Run program now
20 // ./BrainF -jit -abc prog.bf #Run program now safely
21 // ./BrainF prog.bf #Write as BitCode
23 // lli prog.bf.bc #Run generated BitCode
24 // llvm-ld -native -o=prog prog.bf.bc #Compile BitCode into native executable
26 //===--------------------------------------------------------------------===//
29 #include "llvm/Constants.h"
30 #include "llvm/ModuleProvider.h"
31 #include "llvm/Analysis/Verifier.h"
32 #include "llvm/Bitcode/ReaderWriter.h"
33 #include "llvm/ExecutionEngine/GenericValue.h"
34 #include "llvm/ExecutionEngine/JIT.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/ManagedStatic.h"
37 #include "llvm/Target/TargetSelect.h"
42 //Command line options
44 static cl::opt<std::string>
45 InputFilename(cl::Positional, cl::desc("<input brainf>"));
47 static cl::opt<std::string>
48 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
51 ArrayBoundsChecking("abc", cl::desc("Enable array bounds checking"));
54 JIT("jit", cl::desc("Run program Just-In-Time"));
57 //Add main function so can be fully compiled
58 void addMainFunction(Module *mod) {
59 //define i32 @main(i32 %argc, i8 **%argv)
60 Function *main_func = cast<Function>(mod->
61 getOrInsertFunction("main", IntegerType::Int32Ty, IntegerType::Int32Ty,
62 PointerType::getUnqual(PointerType::getUnqual(
63 IntegerType::Int8Ty)), NULL));
65 Function::arg_iterator args = main_func->arg_begin();
66 Value *arg_0 = args++;
67 arg_0->setName("argc");
68 Value *arg_1 = args++;
69 arg_1->setName("argv");
73 BasicBlock *bb = BasicBlock::Create("main.0", main_func);
77 CallInst *brainf_call = CallInst::Create(mod->getFunction("brainf"),
79 brainf_call->setTailCall(false);
83 ReturnInst::Create(ConstantInt::get(APInt(32, 0)), bb);
86 int main(int argc, char **argv) {
87 cl::ParseCommandLineOptions(argc, argv, " BrainF compiler\n");
91 if (InputFilename == "") {
92 std::cerr<<"Error: You must specify the filename of the program to "
93 "be compiled. Use --help to see the options.\n";
97 //Get the output stream
98 std::ostream *out = &std::cout;
100 if (OutputFilename == "") {
101 std::string base = InputFilename;
102 if (InputFilename == "-") {base = "a";}
104 //Use default filename
105 const char *suffix = ".bc";
106 OutputFilename = base+suffix;
108 if (OutputFilename != "-") {
110 ofstream(OutputFilename.c_str(),
111 std::ios::out | std::ios::trunc | std::ios::binary);
115 //Get the input stream
116 std::istream *in = &std::cin;
117 if (InputFilename != "-") {
118 in = new std::ifstream(InputFilename.c_str());
121 //Gather the compile flags
122 BrainF::CompileFlags cf = BrainF::flag_off;
123 if (ArrayBoundsChecking) {
124 cf = BrainF::CompileFlags(cf | BrainF::flag_arraybounds);
127 //Read the BrainF program
129 Module *mod = bf.parse(in, 65536, cf, Context); //64 KiB
130 if (in != &std::cin) {delete in;}
131 addMainFunction(mod);
133 //Verify generated code
134 if (verifyModule(*mod)) {
135 std::cerr<<"Error: module failed verification. This shouldn't happen.\n";
141 InitializeNativeTarget();
143 std::cout << "------- Running JIT -------\n";
144 ExistingModuleProvider *mp = new ExistingModuleProvider(mod);
145 ExecutionEngine *ee = ExecutionEngine::create(mp, false);
146 std::vector<GenericValue> args;
147 Function *brainf_func = mod->getFunction("brainf");
148 GenericValue gv = ee->runFunction(brainf_func, args);
150 WriteBitcodeToFile(mod, *out);
154 if (out != &std::cout) {delete out;}