diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/xixanta/src/assembler.rs | 105 | ||||
| -rw-r--r-- | lib/xixanta/src/node.rs | 14 | ||||
| -rw-r--r-- | lib/xixanta/src/parser.rs | 2 |
3 files changed, 114 insertions, 7 deletions
diff --git a/lib/xixanta/src/assembler.rs b/lib/xixanta/src/assembler.rs index 4b496dc..7d09ec2 100644 --- a/lib/xixanta/src/assembler.rs +++ b/lib/xixanta/src/assembler.rs @@ -253,7 +253,16 @@ impl Assembler { if self.can_bundle { self.literal_mode = None; match self.evaluate_node(node) { - Ok(bundle) => { + Ok(mut bundle) => { + if node.is_branch() { + // TODO: it's a bit of a pity... + let current = &mut self.segments[self.current_segment]; + bundle.address = current.offset; + + if let Err(e) = self.to_relative_address(node, &mut bundle) { + errors.push(Error::Eval(e)); + } + } if let Err(e) = self.push_bundle(bundle, node) { errors.push(Error::Eval(e)); } @@ -292,9 +301,18 @@ impl Assembler { self.context.force_context_switch(&pn.context); match self.evaluate_node(&pn.node) { - Ok(bundle) => { + Ok(mut bundle) => { + // TODO: oh boy + bundle.address = self.segments[pn.segment].bundles[pn.bundle_index].address; + + if pn.node.is_branch() { + if let Err(e) = self.to_relative_address(&pn.node, &mut bundle) { + errors.push(Error::Eval(e)); + } + } + let current = &mut self.segments[pn.segment]; - current.bundles[pn.bundle_index] = bundle; + current.bundles[pn.bundle_index].bytes = bundle.bytes; } Err(e) => errors.push(Error::Eval(e)), } @@ -372,8 +390,9 @@ impl Assembler { } // TODO: move - fn push_bundle(&mut self, bundle: Bundle, node: &PNode) -> Result<(), EvalError> { + fn push_bundle(&mut self, mut bundle: Bundle, node: &PNode) -> Result<(), EvalError> { let current = &mut self.segments[self.current_segment]; + bundle.address = current.offset; current.offset += bundle.size as usize; if current.offset > current.size { @@ -415,6 +434,8 @@ impl Assembler { // just decimal values. Ok(self.evaluate_decimal(node)?) } else if node.value.is_valid_identifier(true).is_err() { + // TODO: relative labels + println!("NODE: {:#?}", node); // If this is not a valid identifier, just error out. Err(EvalError { message: "no prefix was given to operand".to_string(), @@ -978,7 +999,7 @@ impl Assembler { let val = self.evaluate_node(left_arm)?; match self.literal_mode { Some(LiteralMode::Hexadecimal) => { - if val.size == 1 { + if base.is_branch() || val.size == 1 { Ok((AddressingMode::RelativeOrZeropage, val)) } else { Ok((AddressingMode::Absolute, val)) @@ -1004,6 +1025,44 @@ impl Assembler { }), } } + + fn to_relative_address(&self, node: &PNode, bundle: &mut Bundle) -> Result<(), EvalError> { + if !bundle.resolved { + return Ok(()); + } + + let next = (bundle.address + 2) as u16; + let target = u16::from_le_bytes([bundle.bytes[1], bundle.bytes[2]]); + + // println!( + // "NEXT: {:#?} -- TARGET: {:#?} -- BUNDLE: {:#?}", + // next, target, bundle + // ); + + let byte = if target < next { + let diff = target as i16 - next as i16; + if diff < -128 { + return Err(EvalError { + line: node.value.line, + message: "you cannot branch to this location: it's too far away".to_string(), + }); + } + diff.to_le_bytes()[0] + } else { + let diff = target - next; + if diff > 127 { + return Err(EvalError { + line: node.value.line, + message: "you cannot branch to this location: it's too far away".to_string(), + }); + } + diff.to_le_bytes()[0] + }; + + bundle.bytes[1] = byte; + + Ok(()) + } } #[cfg(test)] @@ -1538,8 +1597,40 @@ nop assert_eq!(res[2].bytes[2], 0x00); } - // TODO: anonymous jumps - // TODO: labels & anonymous beq/blt/etc. + // TODO: anonymous jumps & branches + + #[test] + fn conditional_branch_to_labels() { + let mut asm = Assembler::new(EMPTY.to_vec()); + let res = asm + .assemble( + r#" +nop +@hello: + beq @hello + beq @end +@end: + nop +"# + .as_bytes(), + ) + .unwrap(); + + assert_eq!(res.len(), 4); + + // beq @hello + assert_eq!(res[1].size, 2); + assert_eq!(res[1].bytes[0], 0xF0); + assert_eq!(res[1].bytes[1], 0xFE); + + // beq @end + assert_eq!(res[2].size, 2); + assert_eq!(res[2].bytes[0], 0xF0); + assert_eq!(res[2].bytes[1], 0x00); + } + + // TODO: function calls + // TODO: labels and jumps inside of proc's, macros, etc. // Control statements diff --git a/lib/xixanta/src/node.rs b/lib/xixanta/src/node.rs index f55ca11..a28d625 100644 --- a/lib/xixanta/src/node.rs +++ b/lib/xixanta/src/node.rs @@ -164,3 +164,17 @@ pub struct PNode { /// optional arguments. pub args: Option<Vec<PNode>>, } + +impl PNode { + pub fn is_branch(&self) -> bool { + if self.node_type != NodeType::Instruction { + return false; + } + + let opcode = self.value.value.to_lowercase(); + matches!( + opcode.as_str(), + "bcc" | "bcs" | "beq" | "bmi" | "bne" | "bpl" | "bvc" | "bvs" + ) + } +} diff --git a/lib/xixanta/src/parser.rs b/lib/xixanta/src/parser.rs index ec15edd..2c20369 100644 --- a/lib/xixanta/src/parser.rs +++ b/lib/xixanta/src/parser.rs @@ -4,6 +4,8 @@ use crate::opcodes::{CONTROL_FUNCTIONS, INSTRUCTIONS}; use std::cmp::Ordering; use std::io::{self, BufRead, Read}; +// TODO: allow for labels a la ".Lwhatever:" + /// The Parser struct holds basic data for the current parsing session. #[derive(Default)] pub struct Parser { |