1 files changed, 155 insertions, 0 deletions
diff --git a/examples/BrainF/BrainFDriver.cpp b/examples/BrainF/BrainFDriver.cpp
new file mode 100644
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+++ b/examples/BrainF/BrainFDriver.cpp
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+//===-- 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
+// llvm-ld -native -o=prog prog.bf.bc  #Compile BitCode into native executable
+//
+//===--------------------------------------------------------------------===//
+
+#include "BrainF.h"
+#include "llvm/Constants.h"
+#include "llvm/ModuleProvider.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 <fstream>
+#include <iostream>
+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::Int32Ty, IntegerType::Int32Ty,
+                        PointerType::getUnqual(PointerType::getUnqual(
+                          IntegerType::Int8Ty)), 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("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(ConstantInt::get(APInt(32, 0)), bb);
+}
+
+int main(int argc, char **argv) {
+  cl::ParseCommandLineOptions(argc, argv, " BrainF compiler\n");
+
+  if (InputFilename == "") {
+    std::cerr<<"Error: You must specify the filename of the program to "
+    "be compiled.  Use --help to see the options.\n";
+    abort();
+  }
+
+  //Get the output stream
+  std::ostream *out = &std::cout;
+  if (!JIT) {
+    if (OutputFilename == "") {
+      std::string base = InputFilename;
+      if (InputFilename == "-") {base = "a";}
+
+      //Use default filename
+      const char *suffix = ".bc";
+      OutputFilename = base+suffix;
+    }
+    if (OutputFilename != "-") {
+      out = new std::
+        ofstream(OutputFilename.c_str(),
+                 std::ios::out | std::ios::trunc | std::ios::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); //64 KiB
+  if (in != &std::cin) {delete in;}
+  addMainFunction(mod);
+
+  //Verify generated code
+  if (verifyModule(*mod)) {
+    std::cerr<<"Error: module failed verification.  This shouldn't happen.\n";
+    abort();
+  }
+
+  //Write it out
+  if (JIT) {
+    std::cout << "------- Running JIT -------\n";
+    ExistingModuleProvider *mp = new ExistingModuleProvider(mod);
+    ExecutionEngine *ee = ExecutionEngine::create(mp, false);
+    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 != &std::cout) {delete out;}
+  delete mod;
+
+  llvm_shutdown();
+
+  return 0;
+}