llvm-for-llvmta/examples/BrainF/BrainF.h

95 lines
2.7 KiB
C++

//===-- BrainF.h - BrainF compiler class ------------------------*- C++ -*-===//
//
// 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 class stores the data for the BrainF compiler so it doesn't have
// to pass all of it around. The main method is parse.
//
//===----------------------------------------------------------------------===//
#ifndef BRAINF_H
#define BRAINF_H
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include <istream>
using namespace llvm;
/// This class provides a parser for the BrainF language.
/// The class itself is made to store values during
/// parsing so they don't have to be passed around
/// as much.
class BrainF {
public:
/// Options for how BrainF should compile
enum CompileFlags {
flag_off = 0,
flag_arraybounds = 1
};
/// This is the main method. It parses BrainF from in1
/// and returns the module with a function
/// void brainf()
/// containing the resulting code.
/// On error, it calls abort.
/// The caller must delete the returned module.
Module *parse(std::istream *in1, int mem, CompileFlags cf,
LLVMContext& C);
protected:
/// The different symbols in the BrainF language
enum Symbol {
SYM_NONE,
SYM_READ,
SYM_WRITE,
SYM_MOVE,
SYM_CHANGE,
SYM_LOOP,
SYM_ENDLOOP,
SYM_EOF
};
/// Names of the different parts of the language.
/// Tape is used for reading and writing the tape.
/// headreg is used for the position of the head.
/// label is used for the labels for the BasicBlocks.
/// testreg is used for testing the loop exit condition.
static const char *tapereg;
static const char *headreg;
static const char *label;
static const char *testreg;
/// Put the brainf function preamble and other fixed pieces of code
void header(LLVMContext& C);
/// The main loop for parsing. It calls itself recursively
/// to handle the depth of nesting of "[]".
void readloop(PHINode *phi, BasicBlock *oldbb,
BasicBlock *testbb, LLVMContext &Context);
/// Constants during parsing
int memtotal;
CompileFlags comflag;
std::istream *in;
Module *module;
Function *brainf_func;
FunctionCallee getchar_func;
FunctionCallee putchar_func;
Value *ptr_arr;
Value *ptr_arrmax;
BasicBlock *endbb;
BasicBlock *aberrorbb;
/// Variables
IRBuilder<> *builder;
Value *curhead;
};
#endif // BRAINF_H