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/Target/TargetSelect.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/ManagedStatic.h"
38 #include "llvm/Support/raw_ostream.h"
43 //Command line options
45 static cl::opt<std::string>
46 InputFilename(cl::Positional, cl::desc("<input brainf>"));
48 static cl::opt<std::string>
49 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
52 ArrayBoundsChecking("abc", cl::desc("Enable array bounds checking"));
55 JIT("jit", cl::desc("Run program Just-In-Time"));
58 //Add main function so can be fully compiled
59 void addMainFunction(Module *mod) {
60 //define i32 @main(i32 %argc, i8 **%argv)
61 Function *main_func = cast<Function>(mod->
62 getOrInsertFunction("main", IntegerType::getInt32Ty(mod->getContext()),
63 IntegerType::getInt32Ty(mod->getContext()),
64 PointerType::getUnqual(PointerType::getUnqual(
65 IntegerType::getInt8Ty(mod->getContext()))), NULL));
67 Function::arg_iterator args = main_func->arg_begin();
68 Value *arg_0 = args++;
69 arg_0->setName("argc");
70 Value *arg_1 = args++;
71 arg_1->setName("argv");
75 BasicBlock *bb = BasicBlock::Create(mod->getContext(), "main.0", main_func);
79 CallInst *brainf_call = CallInst::Create(mod->getFunction("brainf"),
81 brainf_call->setTailCall(false);
85 ReturnInst::Create(mod->getContext(),
86 ConstantInt::get(mod->getContext(), APInt(32, 0)), bb);
89 int main(int argc, char **argv) {
90 cl::ParseCommandLineOptions(argc, argv, " BrainF compiler\n");
92 LLVMContext &Context = getGlobalContext();
94 if (InputFilename == "") {
95 errs() << "Error: You must specify the filename of the program to "
96 "be compiled. Use --help to see the options.\n";
100 //Get the output stream
101 raw_ostream *out = &outs();
103 if (OutputFilename == "") {
104 std::string base = InputFilename;
105 if (InputFilename == "-") { base = "a"; }
107 // Use default filename.
108 OutputFilename = base+".bc";
110 if (OutputFilename != "-") {
112 out = new raw_fd_ostream(OutputFilename.c_str(), ErrInfo,
113 raw_fd_ostream::F_Binary);
117 //Get the input stream
118 std::istream *in = &std::cin;
119 if (InputFilename != "-")
120 in = new std::ifstream(InputFilename.c_str());
122 //Gather the compile flags
123 BrainF::CompileFlags cf = BrainF::flag_off;
124 if (ArrayBoundsChecking)
125 cf = BrainF::CompileFlags(cf | BrainF::flag_arraybounds);
127 //Read the BrainF program
129 Module *mod = bf.parse(in, 65536, cf, Context); //64 KiB
132 addMainFunction(mod);
134 //Verify generated code
135 if (verifyModule(*mod)) {
136 errs() << "Error: module failed verification. This shouldn't happen.\n";
142 InitializeNativeTarget();
144 outs() << "------- Running JIT -------\n";
145 ExecutionEngine *ee = EngineBuilder(mod).create();
146 std::vector<GenericValue> args;
147 Function *brainf_func = mod->getFunction("brainf");
148 GenericValue gv = ee->runFunction(brainf_func, args);
150 WriteBitcodeToFile(mod, *out);