1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
use crate::*;
use std::collections::HashMap;
pub struct BytecodeGenerator<'a> {
tokens: &'a [AssembledToken],
addresses: HashMap<String, Tracked<usize>>,
words: Vec<Word>,
errors: Vec<BytecodeError>,
}
impl<'a> BytecodeGenerator<'a> {
pub fn new(tokens: &'a [AssembledToken]) -> Self {
Self {
tokens,
addresses: HashMap::new(),
words: Vec::new(),
errors: Vec::new(),
}
}
pub fn generate(mut self) -> Bytecode {
self.calculate_addresses();
for token in self.tokens {
match token {
AssembledToken::Word(assembled_word) => {
self.assemble_word(assembled_word);
}
AssembledToken::PinnedAddress(pinned) => {
if self.words.len() > pinned.address {
let variant = BytecodeErrorVariant::PinnedAddressBacktrack(
pinned.address, self.words.len());
let source = pinned.source.clone();
self.errors.push(BytecodeError { source, variant });
} else {
self.words.resize(pinned.address, Word { bits: 0, value: 0});
}
}
AssembledToken::LabelDefinition(_) => (),
AssembledToken::Error(_) => (),
}
}
return Bytecode {
words: self.words,
errors: self.errors,
}
}
fn calculate_addresses(&mut self) {
let mut i = 0;
for token in self.tokens {
match token {
AssembledToken::LabelDefinition(definition) => {
let address = Tracked::from(i, definition.source.clone());
if let Some(_) = self.addresses.insert(definition.name.clone(), address) {
let name = definition.name.clone();
let variant = BytecodeErrorVariant::DuplicateLabelDefinition(name);
let source = definition.source.clone();
self.errors.push(BytecodeError { source, variant });
}
}
AssembledToken::Word(word) => {
i += word.count();
}
AssembledToken::PinnedAddress(pinned) => {
i = pinned.address;
}
AssembledToken::Error(_) => (),
}
}
}
fn resolve_expression(&mut self, expr: &AssembledExpression) -> isize {
let mut stack = Vec::new();
macro_rules! push {
($value:expr) => { stack.push($value) };
}
macro_rules! pop {
($name:ident) => { let $name = match stack.pop() {
Some(value) => value,
None => {
let variant = BytecodeErrorVariant::StackUnderflow;
self.errors.push(BytecodeError { source: expr.source.clone(), variant });
return 0;
},
}; };
}
macro_rules! truth {
($bool:expr) => { match $bool { true => 1, false => 0 } };
}
for token in &expr.tokens {
match &token {
AssembledExpressionToken::Integer(value) => {
push!(value.value)
}
AssembledExpressionToken::LabelReference(name) => {
push!(self.resolve_label_reference(name))
}
AssembledExpressionToken::Expression(expr) => {
push!(self.resolve_expression(expr))
}
AssembledExpressionToken::Operator(operator) => match operator {
Operator::Equal => { pop!(b); pop!(a); push!(truth!(a==b)) },
Operator::NotEqual => { pop!(b); pop!(a); push!(truth!(a!=b)) },
Operator::LessThan => { pop!(b); pop!(a); push!(truth!(a < b)) },
Operator::GreaterThan => { pop!(b); pop!(a); push!(truth!(a > b)) },
Operator::Add => { pop!(b); pop!(a); push!(a + b) },
Operator::Subtract => { pop!(b); pop!(a); push!(a - b) },
Operator::LeftShift => { pop!(b); pop!(a); push!(a << b) },
Operator::RightShift => { pop!(b); pop!(a); push!(a >> b) },
Operator::And => { pop!(b); pop!(a); push!(a & b) },
Operator::Or => { pop!(b); pop!(a); push!(a | b) },
Operator::Xor => { pop!(b); pop!(a); push!(a ^ b) },
Operator::Not => { pop!(a); push!(!a) },
}
}
}
let variant = match stack.len() {
0 => BytecodeErrorVariant::NoReturnValue,
1 => return stack[0],
_ => BytecodeErrorVariant::MultipleReturnValues,
};
self.errors.push(BytecodeError { source: expr.source.clone(), variant});
0
}
fn resolve_label_reference(&mut self, name: &Tracked<String>) -> isize {
if let Some(address) = self.addresses.get(&name.value) {
address.value as isize
} else {
let variant = BytecodeErrorVariant::DefinitionNotFound(name.value.clone());
self.errors.push(BytecodeError { source: name.source.clone(), variant });
0
}
}
fn assemble_word(&mut self, assembled_word: &AssembledWord) {
let mut field_values = Vec::new();
for field in &assembled_word.fields {
match &field.value {
IntegerArgument::Expression(expr) => {
let source = expr.source.clone();
let value = self.resolve_expression(expr);
field_values.push(vec![Tracked::from(value, source)])
}
IntegerArgument::LabelReference(name) => {
let source = name.source.clone();
let value = self.resolve_label_reference(name);
field_values.push(vec![Tracked::from(value, source)])
}
IntegerArgument::Integer(integer) => {
let source = integer.source.clone();
let value = integer.value;
field_values.push(vec![Tracked::from(value, source)])
}
IntegerArgument::String(string) => {
let values = string.chars.iter()
.map(|c| Tracked::from(c.value as isize, c.source.clone()))
.collect();
field_values.push(values);
}
};
}
for i in 0..assembled_word.count() {
let mut value = assembled_word.value;
for (f, field) in assembled_word.fields.iter().enumerate() {
let (field_value, source) = match field_values[f].get(i) {
Some(tracked) => (tracked.value, Some(tracked.source.clone())),
None => (0, None),
};
let bitcount = match field_value {
0 => 0,
_ => (field_value.ilog2() + 1) as usize,
};
if field.bits < bitcount {
let variant = BytecodeErrorVariant::ValueTooLarge(field.bits, bitcount);
self.errors.push(BytecodeError { source: source.unwrap(), variant });
} else {
value |= (field_value << field.shift) as usize;
}
}
self.words.push(Word { bits: assembled_word.bits, value });
}
}
}
|
