public static void Main(string[] args)
{
if (args.Length < 1)
{
BfUtil.DIE("argv < 1");
}
string bfCode = BfUtil.LoadProgram(args[0]);
byte[] memory = new byte[30000];
Run(memory, bfCode);
}
public static void Main(string[] args)
{
if (args.Length < 1)
{
BfUtil.DIE("argv < 1");
}
string bfCode = BfUtil.LoadProgram(args[0]);
//Console.WriteLine(bfCode);
var gen = new BfGen();
var program = gen.Gen(bfCode);
byte[] memory = new byte[30000];
program.Invoke(memory);
}
public static void Main(string[] args)
{
if (args.Length < 1)
{
BfUtil.DIE("argv < 1");
}
string bfCode = BfUtil.LoadProgram(args[0]);
List <BfOp> optimized = translate_program(bfCode);
//foreach (BfOp op in optimized) {
// Console.WriteLine($"op={op.kind}, argument={op.argument}");
//}
var gen = new BfGen();
var program = gen.Gen(optimized);
byte[] memory = new byte[30000];
program.Invoke(memory);
}
public static void Run(byte[] memory, string instructions)
{
int pc = 0;
int dataptr = 0;
while (pc < instructions.Length)
{
char instruction = instructions[pc];
switch (instruction)
{
case '>':
dataptr++;
break;
case '<':
dataptr--;
break;
case '+':
memory[dataptr]++;
break;
case '-':
memory[dataptr]--;
break;
case '.':
BfUtil.PutChar((char)memory[dataptr]);
break;
case ',':
memory[dataptr] = (byte)BfUtil.GetChar();
break;
case '[':
if (memory[dataptr] == 0)
{
int bracket_nesting = 1;
int saved_pc = pc;
while (bracket_nesting > 0 && ++pc < instructions.Length)
{
if (instructions[pc] == ']')
{
bracket_nesting--;
}
else if (instructions[pc] == '[')
{
bracket_nesting++;
}
}
if (bracket_nesting == 0)
{
break;
}
else
{
BfUtil.DIE($"unmatched '[' at pc={saved_pc}");
}
}
break;
case ']':
if (memory[dataptr] != 0)
{
int bracket_nesting = 1;
int saved_pc = pc;
while (bracket_nesting > 0 && pc > 0)
{
pc--;
if (instructions[pc] == '[')
{
bracket_nesting--;
}
else if (instructions[pc] == ']')
{
bracket_nesting++;
}
}
if (bracket_nesting == 0)
{
break;
}
else
{
BfUtil.DIE($"unmatched ']' at pc={saved_pc}");
}
}
break;
default:
BfUtil.DIE($"bad char '{instruction}' at pc={pc}");
break;
}
pc++;
}
}
private MethodBuilder DefineInvokeMethod(TypeBuilder myType, List <BfOp> ops)
{
MethodBuilder simpleMethod = myType.DefineMethod("Invoke",
MethodAttributes.Public | MethodAttributes.Virtual,
typeof(void), // returnType
new Type[] { typeof(byte[]) }); // ;paramTypes
ILGenerator generator = simpleMethod.GetILGenerator();
MethodInfo putcharMI = typeof(BfUtil).GetMethod("PutChar",
new Type[] { typeof(char) });
MethodInfo getcharMI = typeof(BfUtil).GetMethod("GetChar",
new Type[] {});
Stack <BracketLabels> openBracketStack = new Stack <BracketLabels>();
LocalBuilder dataptr = generator.DeclareLocal(typeof(int)); // local0: pc
LocalBuilder tempptr = generator.DeclareLocal(typeof(int)); // local1: temporary
generator.Emit(OpCodes.Ldc_I4_0);
generator.Emit(OpCodes.Stloc, dataptr); // dataptr = 0
for (int pc = 0; pc < ops.Count; ++pc)
{
BfOp op = ops[pc];
switch (op.kind)
{
case BfOpKind.INC_PTR:
generator.Emit(OpCodes.Ldloc, dataptr);
generator.Emit(OpCodes.Ldc_I4, op.argument);
generator.Emit(OpCodes.Add);
generator.Emit(OpCodes.Stloc, dataptr); // dataptr += <op.argument>
break;
case BfOpKind.DEC_PTR:
generator.Emit(OpCodes.Ldloc, dataptr);
generator.Emit(OpCodes.Ldc_I4, op.argument);
generator.Emit(OpCodes.Sub);
generator.Emit(OpCodes.Stloc, dataptr); // dataptr += <op.argument>
break;
case BfOpKind.INC_DATA:
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, op.argument);
generator.Emit(OpCodes.Add);
generator.Emit(OpCodes.Stelem_I4); // memory[dataptr] += <op.argument>
break;
case BfOpKind.DEC_DATA:
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, op.argument);
generator.Emit(OpCodes.Sub);
generator.Emit(OpCodes.Stelem_I4); // memory[dataptr] -= <op.argument>
break;
case BfOpKind.WRITE_STDOUT:
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
for (int i = 0; i < op.argument; ++i)
{
if (i < op.argument - 1)
{
generator.Emit(OpCodes.Dup);
}
generator.EmitCall(OpCodes.Call, putcharMI, null); // putchar(memory[dataptr])
}
break;
case BfOpKind.READ_STDIN:
for (int i = 0; i < op.argument; ++i)
{
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.EmitCall(OpCodes.Call, getcharMI, null); // getchar()
generator.Emit(OpCodes.Stelem_I4); // memory[pc] = getchar()
}
break;
case BfOpKind.LOOP_SET_TO_ZERO:
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Stelem_I4); // memory[dataptr] = 0
break;
case BfOpKind.LOOP_MOVE_PTR:
{
Label loop = generator.DefineLabel();
Label endloop = generator.DefineLabel();
// Emit a loop that moves the pointer in jumps of op.argument; it's
// important to do an equivalent of while(...) rather than do...while(...)
// here so that we don't do the first pointer change if already pointing
// to a zero.
//
// loop:
// cmpb 0(%r13), 0
// jz endloop
// %r13 += argument
// jmp loop
// endloop:
generator.MarkLabel(loop);
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, 255);
generator.Emit(OpCodes.And);
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Beq, endloop); // if memory[dataptr] == 0 goto endloop
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
if (op.argument < 0)
{
generator.Emit(OpCodes.Ldc_I4, -op.argument);
generator.Emit(OpCodes.Sub);
}
else
{
generator.Emit(OpCodes.Ldc_I4, op.argument);
generator.Emit(OpCodes.Add);
}
generator.Emit(OpCodes.Stloc, dataptr); // dataptr += <op.argument>
generator.Emit(OpCodes.Br, loop);
generator.MarkLabel(endloop);
}
break;
case BfOpKind.LOOP_MOVE_DATA:
{
// Only move if the current data isn't 0:
//
// cmpb 0(%r13), 0
// jz skip_move
// <...> move data
// skip_move:
Label skip_move = generator.DefineLabel();
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, 255);
generator.Emit(OpCodes.And);
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Beq, skip_move);
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
if (op.argument < 0)
{
generator.Emit(OpCodes.Ldc_I4, -op.argument);
generator.Emit(OpCodes.Sub);
}
else
{
generator.Emit(OpCodes.Ldc_I4, op.argument);
generator.Emit(OpCodes.Add);
}
generator.Emit(OpCodes.Stloc, tempptr); // temp = dataptr + <op.argument>
// Use rax as a temporary holding the value of at the original pointer;
// then use al to add it to the new location, so that only the target
// location is affected: addb %al, 0(%r13)
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, tempptr); // temp
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, tempptr); // temp
generator.Emit(OpCodes.Ldelem_I4); // memory[temp]
generator.Emit(OpCodes.Add); // memory[dataptr] + memory[temp]
generator.Emit(OpCodes.Stelem_I4); // memory[temp] = memory[dataptr] + memory[temp]
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Stelem_I4); // memory[dataptr] = 0
generator.MarkLabel(skip_move);
}
break;
case BfOpKind.JUMP_IF_DATA_ZERO:
{
Label openLabel = generator.DefineLabel();
Label closeLabel = generator.DefineLabel();
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, 255);
generator.Emit(OpCodes.And);
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Beq, closeLabel); // if memory[dataptr] == 0 goto closeLabel
generator.MarkLabel(openLabel);
openBracketStack.Push(new BracketLabels(openLabel, closeLabel));
}
break;
case BfOpKind.JUMP_IF_DATA_NOT_ZERO:
{
if (openBracketStack.Count == 0)
{
BfUtil.DIE($"Unmatched closing ']' at pc={pc}");
}
BracketLabels labels = openBracketStack.Pop();
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, 255);
generator.Emit(OpCodes.And);
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Bne_Un, labels.openLabel); // if memory[dataptr] != 0 goto openLabel
generator.MarkLabel(labels.closeLabel);
}
break;
default:
BfUtil.DIE($"INVALID_OP encountered on pc={pc}");
break;
}
}
generator.Emit(OpCodes.Ret);
return(simpleMethod);
}
// Translates the given program into a vector of BfOps that can be used for fast
// interpretation.
private static List <BfOp> translate_program(string instructions)
{
int pc = 0;
int program_size = instructions.Length;
List <BfOp> ops = new List <BfOp>();
// Throughout the translation loop, this stack contains offsets (in the ops
// vector) of open brackets (JUMP_IF_DATA_ZERO ops) waiting for a closing
// bracket. Since brackets nest, these naturally form a stack. The
// JUMP_IF_DATA_ZERO ops get added to ops with their argument set to 0 until a
// matching closing bracket is encountered, at which point the argument can be
// back-patched.
Stack <int> open_bracket_stack = new Stack <int>();
while (pc < program_size)
{
char instruction = instructions[pc];
if (instruction == '[')
{
// Place a jump op with a placeholder 0 offset. It will be patched-up to
// the right offset when the matching ']' is found.
open_bracket_stack.Push(ops.Count);
ops.Add(new BfOp(BfOpKind.JUMP_IF_DATA_ZERO, 0));
pc++;
}
else if (instruction == ']')
{
if (open_bracket_stack.Count == 0)
{
BfUtil.DIE($"unmatched closing ']' at pc={pc}");
}
int open_bracket_offset = open_bracket_stack.Pop();
// Try to optimize this loop; if optimize_loop succeeds, it returns a
// non-empty vector which we can splice into ops in place of the loop.
// If the returned vector is empty, we proceed as usual.
List <BfOp> optimized_loop = optimize_loop(ops, open_bracket_offset);
if (optimized_loop.Count == 0)
{
// Loop wasn't optimized, so proceed emitting the back-jump to ops. We
// have the offset of the matching '['. We can use it to create a new
// jump op for the ']' we're handling, as well as patch up the offset of
// the matching '['.
ops[open_bracket_offset].argument = ops.Count;
ops.Add(new BfOp(BfOpKind.JUMP_IF_DATA_NOT_ZERO, open_bracket_offset));
}
else
{
// Replace this whole loop with optimized_loop.
ops.RemoveRange(open_bracket_offset, ops.Count - open_bracket_offset);
ops.AddRange(optimized_loop);
}
pc++;
}
else
{
// Not a jump; all the other ops can be repeated, so find where the repeat
// ends.
int start = pc++;
while (pc < program_size && instructions[pc] == instruction)
{
pc++;
}
// Here pc points to the first new instruction encountered, or to the end
// of the program.
int num_repeats = pc - start;
// Figure out which op kind the instruction represents and add it to the
// ops.
BfOpKind kind = BfOpKind.INVALID_OP;
switch (instruction)
{
case '>':
kind = BfOpKind.INC_PTR;
break;
case '<':
kind = BfOpKind.DEC_PTR;
break;
case '+':
kind = BfOpKind.INC_DATA;
break;
case '-':
kind = BfOpKind.DEC_DATA;
break;
case ',':
kind = BfOpKind.READ_STDIN;
break;
case '.':
kind = BfOpKind.WRITE_STDOUT;
break;
default:
BfUtil.DIE($"bad char '{instruction}' at pc={start}");
break;
}
ops.Add(new BfOp(kind, num_repeats));
}
}
return(ops);
}
private MethodBuilder DefineInvokeMethod(TypeBuilder myType, string instructions)
{
MethodBuilder simpleMethod = myType.DefineMethod("Invoke",
MethodAttributes.Public | MethodAttributes.Virtual,
typeof(void), // returnType
new Type[] { typeof(byte[]) }); // ;paramTypes
ILGenerator generator = simpleMethod.GetILGenerator();
MethodInfo putcharMI = typeof(BfUtil).GetMethod("PutChar",
new Type[] { typeof(char) });
MethodInfo getcharMI = typeof(BfUtil).GetMethod("GetChar",
new Type[] {});
Stack <BracketLabels> openBracketStack = new Stack <BracketLabels>();
LocalBuilder dataptr = generator.DeclareLocal(typeof(int)); // local0: pc
generator.Emit(OpCodes.Ldc_I4_0);
generator.Emit(OpCodes.Stloc, dataptr); // dataptr = 0
for (int pc = 0; pc < instructions.Length; ++pc)
{
char c = instructions[pc];
switch (c)
{
case '>':
generator.Emit(OpCodes.Ldloc, dataptr);
generator.Emit(OpCodes.Ldc_I4_1);
generator.Emit(OpCodes.Add);
generator.Emit(OpCodes.Stloc, dataptr); // ++dataptr
break;
case '<':
generator.Emit(OpCodes.Ldloc, dataptr);
generator.Emit(OpCodes.Ldc_I4_1);
generator.Emit(OpCodes.Sub);
generator.Emit(OpCodes.Stloc, dataptr); // --dataptr
break;
case '+':
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr);
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4_1);
generator.Emit(OpCodes.Add);
generator.Emit(OpCodes.Stelem_I4); // memory[dataptr] += 1
break;
case '-':
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4_1);
generator.Emit(OpCodes.Sub);
generator.Emit(OpCodes.Stelem_I4); // memory[pc] -= 1
break;
case '.':
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.EmitCall(OpCodes.Call, putcharMI, null); // putchar(memory[dataptr])
break;
case ',':
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.EmitCall(OpCodes.Call, getcharMI, null); // getchar()
generator.Emit(OpCodes.Stelem_I4); // memory[dataptr] = getchar()
break;
case '[':
{
Label openLabel = generator.DefineLabel();
Label closeLabel = generator.DefineLabel();
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, 255);
generator.Emit(OpCodes.And);
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Beq, closeLabel); // if memory[pc] == 0 goto closeLabel
generator.MarkLabel(openLabel);
openBracketStack.Push(new BracketLabels(openLabel, closeLabel));
}
break;
case ']':
{
if (openBracketStack.Count == 0)
{
BfUtil.DIE($"Unmatched closing ']' at pc={pc}");
}
BracketLabels labels = openBracketStack.Pop();
generator.Emit(OpCodes.Ldarg_1); // memory
generator.Emit(OpCodes.Ldloc, dataptr); // dataptr
generator.Emit(OpCodes.Ldelem_I4); // memory[dataptr]
generator.Emit(OpCodes.Ldc_I4, 255);
generator.Emit(OpCodes.And);
generator.Emit(OpCodes.Ldc_I4_0); // 0
generator.Emit(OpCodes.Bne_Un, labels.openLabel); // if memory[pc] != 0 goto openLabel
generator.MarkLabel(labels.closeLabel);
}
break;
default:
Console.WriteLine("Unhandled instruction: " + c);
break;
}
}
generator.Emit(OpCodes.Ret);
return(simpleMethod);
}