vox-lang 0.4.6

A systems level compiler for Vox (sentence based code)
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
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207

use super::*;

impl CodeGenerator {
    pub(crate) fn emit_clear_buffer_target(&mut self, target: &VarTarget) {
        self.uses_buffers = true;
        match target {
            VarTarget::Local(offset) => {
                self.emit_indent(&format!("mov rdi, [rbp-{}]", offset));
                self.emit_indent("call _buffer_clear");
                self.emit_indent(&format!("mov [rbp-{}], rax", offset));
            }
            VarTarget::Global(label) => {
                self.emit_indent(&format!("mov rdi, [rel {}]", label));
                self.emit_indent("call _buffer_clear");
                self.emit_indent(&format!("mov [rel {}], rax", label));
            }
        }
    }

    pub(crate) fn emit_append_runtime_value_to_buffer_target(
        &mut self,
        target: &VarTarget,
        value_type: Option<VarType>,
        fmt: FormatSpec,
    ) {
        match target {
            VarTarget::Local(offset) => {
                self.emit_append_runtime_value_to_buffer_slot(*offset, value_type, fmt);
            }
            VarTarget::Global(label) => {
                self.emit_indent(&format!("mov rdi, [rel {}]", label));
                self.emit_append_runtime_value_to_buffer_ptr(value_type, fmt);
                self.emit_indent(&format!("mov [rel {}], rax", label));
            }
        }
    }

    pub(crate) fn emit_clear_buffer_slot(&mut self, offset: i64) {
        self.uses_buffers = true;
        self.emit_indent(&format!("mov rdi, [rbp-{}]", offset));
        self.emit_indent("call _buffer_clear");
        self.emit_indent(&format!("mov [rbp-{}], rax", offset));
    }

    pub(crate) fn emit_append_literal_to_buffer_slot(&mut self, offset: i64, text: &str) {
        self.uses_buffers = true;
        let label = self.add_string(text);
        self.emit_indent(&format!("mov rdi, [rbp-{}]", offset));
        self.emit_indent(&format!("lea rsi, [rel {}]", label));
        self.emit_indent(&format!("mov rdx, {}_len", label));
        self.emit_indent("call _buffer_append_bytes");
        self.emit_indent(&format!("mov [rbp-{}], rax", offset));
    }

    pub(crate) fn emit_append_formatted_int_to_buffer(&mut self, fmt: FormatSpec) {
        self.uses_buffers = true;
        let (base, uppercase) = match fmt.base {
            IntegerBase::Decimal => (0, 0),
            IntegerBase::HexLower => (1, 0),
            IntegerBase::HexUpper => (1, 1),
            IntegerBase::Binary => (2, 0),
            IntegerBase::Octal => (3, 0),
        };
        let width = fmt.width.unwrap_or(0);
        let zero_pad = if fmt.zero_pad { 1 } else { 0 };

        self.emit_indent("mov rsi, rax");
        self.emit_indent(&format!("mov rdx, {}", width));
        self.emit_indent(&format!("mov rcx, {}", zero_pad));
        self.emit_indent(&format!("mov r8, {}", base));
        self.emit_indent(&format!("mov r9, {}", uppercase));
        self.emit_indent("call _buffer_append_formatted_int");
    }

    pub(crate) fn emit_append_runtime_value_to_buffer_ptr(&mut self, value_type: Option<VarType>, fmt: FormatSpec) {
        match value_type {
            Some(VarType::Buffer) => {
                self.uses_buffers = true;
                self.emit_indent("mov rsi, rax");
                self.emit_indent("call _buffer_append");
            }
            Some(VarType::String) => {
                self.uses_buffers = true;
                self.emit_indent("mov rsi, rax");
                self.emit_indent("call _buffer_append_cstr");
            }
            Some(VarType::Float) => {
                // A float interpolated into a text/buffer destination (e.g.
                // `a text called t is "{y}".`) has its IEEE-754 bits in rax.
                // Without this arm it fell through to the integer formatter
                // and printed the raw bit pattern as a decimal integer
                // (e.g. 3.5 -> 4615063718147915776). _buffer_append_float takes
                // rdi = destination buffer (already loaded by the caller) and
                // rax = raw float bits, and returns the (possibly reallocated)
                // destination buffer in rax — matching the Buffer/String arms.
                // The Print path never hit this because it formats through
                // emit_formatted_value, which already had a Float arm.
                self.uses_buffers = true;
                self.uses_floats = true;
                self.emit_indent("call _buffer_append_float");
            }
            _ => {
                self.emit_append_formatted_int_to_buffer(fmt);
            }
        }
    }

    pub(crate) fn emit_append_runtime_value_to_buffer_slot(
        &mut self,
        offset: i64,
        value_type: Option<VarType>,
        fmt: FormatSpec,
    ) {
        self.emit_indent(&format!("mov rdi, [rbp-{}]", offset));
        self.emit_append_runtime_value_to_buffer_ptr(value_type, fmt);
        self.emit_indent(&format!("mov [rbp-{}], rax", offset));
    }

    pub(crate) fn emit_copy_expr_into_buffer_slot(
        &mut self,
        value: &Expr,
        clear_first: bool,
        dst_local: Option<i64>,
        dst_global: Option<&str>,
    ) -> bool {
        self.uses_buffers = true;
        let emit_dst_load = |this: &mut Self| {
            if let Some(offset) = dst_local {
                this.emit_indent(&format!("mov rdi, [rbp-{}]", offset));
            } else if let Some(label) = dst_global {
                this.emit_indent(&format!("mov rdi, [rel {}]", label));
            }
        };
        let emit_dst_store = |this: &mut Self| {
            if let Some(offset) = dst_local {
                this.emit_indent(&format!("mov [rbp-{}], rax", offset));
            } else if let Some(label) = dst_global {
                this.emit_indent(&format!("mov [rel {}], rax", label));
            }
        };

        match value {
            Expr::FormatString { parts } => {
                if clear_first {
                    emit_dst_load(self);
                    self.emit_indent("push rdi");
                    self.emit_indent("call _buffer_clear");
                    self.emit_indent("mov rdi, rax");
                    self.emit_indent("pop rsi  ; discard original pointer copy");
                }
                self.emit_format_parts_into_buffer(dst_local, dst_global, parts);
                true
            }
            Expr::StringLit(s) => {
                // A string literal is data, never a name (bug #30 / #19's
                // family). Initialise from the literal bytes unconditionally;
                // the text is never looked up as a variable. Copying a named
                // buffer into another is spelled with an *unquoted* identifier
                // (the `Expr::Identifier` arm below), never a string literal,
                // so deleting this lookup removes the silent substitution
                // without losing the buffer-to-buffer feature.
                if clear_first {
                    if let Some(offset) = dst_local {
                        self.emit_clear_buffer_slot(offset);
                    } else if let Some(label) = dst_global {
                        self.emit_indent(&format!("mov rdi, [rel {}]", label));
                        self.emit_indent("call _buffer_clear");
                        self.emit_indent(&format!("mov [rel {}], rax", label));
                    }
                }
                if let Some(offset) = dst_local {
                    self.emit_append_literal_to_buffer_slot(offset, s);
                } else if let Some(label) = dst_global {
                    let lit_label = self.add_string(s);
                    self.emit_indent(&format!("mov rdi, [rel {}]", label));
                    self.emit_indent(&format!("lea rsi, [rel {}]", lit_label));
                    self.emit_indent(&format!("mov rdx, {}_len", lit_label));
                    self.emit_indent("call _buffer_append_bytes");
                    self.emit_indent(&format!("mov [rel {}], rax", label));
                }
                true
            }
            Expr::Identifier(name) => {
                if self.variable_types.get(name) == Some(&VarType::Buffer) {
                    if let Some(src_offset) = self.get_var(name) {
                        self.uses_buffers = true;
                        emit_dst_load(self);
                        self.emit_indent(&format!("mov rsi, [rbp-{}]", src_offset));
                        self.emit_indent(if clear_first { "call _buffer_copy" } else { "call _buffer_append" });
                        emit_dst_store(self);
                        return true;
                    } else if let Some(label) = self.global_var_label(name).cloned() {
                        self.uses_buffers = true;
                        emit_dst_load(self);
                        self.emit_indent(&format!("mov rsi, [rel {}]", label));
                        self.emit_indent(if clear_first { "call _buffer_copy" } else { "call _buffer_append" });
                        emit_dst_store(self);
                        return true;
                    }
                }
                false
            }
            _ => false,
        }
    }

}