diff options
| -rw-r--r-- | src/display.rs | 14 | ||||
| -rw-r--r-- | src/lib.rs | 52 |
2 files changed, 47 insertions, 19 deletions
diff --git a/src/display.rs b/src/display.rs index 4593f20..7836d10 100644 --- a/src/display.rs +++ b/src/display.rs @@ -1,6 +1,6 @@ -use ::{MSP430, Operand, Opcode, Instruction, Width}; +use ::{MSP430, Operand, Opcode, Instruction, Width, DecodeError}; -use std::fmt::{Display, Formatter}; +use std::fmt::{self, Display, Formatter}; use std; use yaxpeax_arch::{Arch, Colorize, ColorSettings, ShowContextual}; @@ -12,6 +12,16 @@ impl Display for Instruction { } } +impl fmt::Display for DecodeError { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + match self { + DecodeError::ExhaustedInput => write!(f, "exhausted input"), + DecodeError::InvalidOpcode => write!(f, "invalid opcode"), + DecodeError::InvalidOperand => write!(f, "invalid operand"), + } + } +} + impl <T: std::fmt::Write> ShowContextual<<MSP430 as Arch>::Address, [Option<String>], T> for Instruction { fn contextualize(&self, _colors: Option<&ColorSettings>, _address: <MSP430 as Arch>::Address, _context: Option<&[Option<String>]>, out: &mut T) -> std::fmt::Result { write!(out, "{}", self.opcode)?; @@ -23,6 +23,7 @@ pub struct MSP430; impl Arch for MSP430 { type Address = u16; type Instruction = Instruction; + type DecodeError = DecodeError; type Decoder = InstDecoder; type Operand = Operand; } @@ -125,23 +126,40 @@ pub enum Operand { Nothing } +#[derive(Debug, PartialEq)] +pub enum DecodeError { + ExhaustedInput, + InvalidOpcode, + InvalidOperand, +} + +impl yaxpeax_arch::DecodeError for DecodeError { + fn data_exhausted(&self) -> bool { self == &DecodeError::ExhaustedInput } + fn bad_opcode(&self) -> bool { self == &DecodeError::InvalidOpcode } + fn bad_operand(&self) -> bool { self == &DecodeError::InvalidOperand } +} + +impl yaxpeax_arch::Instruction for Instruction { + // TODO: this is wrong!! + fn well_defined(&self) -> bool { true } +} + #[derive(Default, Debug)] pub struct InstDecoder {} impl Decoder<Instruction> for InstDecoder { - fn decode<T: IntoIterator<Item=u8>>(&self, bytes: T) -> Option<Instruction> { + type Error = DecodeError; + + fn decode<T: IntoIterator<Item=u8>>(&self, bytes: T) -> Result<Instruction, Self::Error> { let mut inst = Instruction::blank(); - match self.decode_into(&mut inst, bytes) { - Some(_) => Some(inst), - None => None - } + self.decode_into(&mut inst, bytes).map(|_: ()| inst) } - fn decode_into<T: IntoIterator<Item=u8>>(&self, inst: &mut Instruction, bytes: T) -> Option<()> { + fn decode_into<T: IntoIterator<Item=u8>>(&self, inst: &mut Instruction, bytes: T) -> Result<(), Self::Error> { let mut bytes_iter = bytes.into_iter(); let word: Vec<u8> = bytes_iter.by_ref().take(2).collect(); let fullword = match word[..] { - [] | [_] => { return None; }, + [] | [_] => { return Err(DecodeError::ExhaustedInput); }, [low, high] => (high as u16) << 8 | (low as u16), _ => unreachable!() }; @@ -245,7 +263,7 @@ impl Decoder<Instruction> for InstDecoder { } else { if x == 1 || x == 3 || x == 5 { inst.opcode = Opcode::Invalid(instrword); - return None; + return Err(DecodeError::InvalidOpcode); } Width:: B }; @@ -256,25 +274,25 @@ impl Decoder<Instruction> for InstDecoder { ); if !decode_operand(&mut bytes_iter, source, As, &mut inst.operands[0]) { inst.opcode = Opcode::Invalid(instrword); - return None; + return Err(DecodeError::InvalidOperand); }; inst.operands[1] = Operand::Nothing; - Some(()) + Ok(()) }, 6 => { if operands == 0 { inst.opcode = Opcode::RETI; inst.operands[0] = Operand::Nothing; inst.operands[1] = Operand::Nothing; - Some(()) + Ok(()) } else { inst.opcode = Opcode::Invalid(instrword); - return None; + return Err(DecodeError::InvalidOperand); } } 7 => { inst.opcode = Opcode::Invalid(instrword); - return None; + return Err(DecodeError::InvalidOpcode); } _ => { unreachable!(); @@ -295,7 +313,7 @@ impl Decoder<Instruction> for InstDecoder { ][opcode_idx as usize]; inst.operands[0] = Operand::Offset(((offset as i16) << 6) >> 6); inst.operands[1] = Operand::Nothing; - Some(()) + Ok(()) }, instrword @ _ => { let (opcode_idx, operands) = ((instrword & 0xf000) >> 12, instrword & 0x0fff); @@ -323,13 +341,13 @@ impl Decoder<Instruction> for InstDecoder { ); if !decode_operand(&mut bytes_iter, source, As, &mut inst.operands[0]) { inst.opcode = Opcode::Invalid(instrword); - return None; + return Err(DecodeError::InvalidOperand); } if !decode_operand(&mut bytes_iter, dest, Ad, &mut inst.operands[1]) { inst.opcode = Opcode::Invalid(instrword); - return None; + return Err(DecodeError::InvalidOperand); } - Some(()) + Ok(()) } } } |