beamr 0.4.9

A Rust runtime with the BEAM's execution model, targeting Gleam
Documentation
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
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
//! Unit tests for decoded `bs_create_bin` segment handling.
//!
//! Operand shapes mirror what the loader produces for real compiler
//! output: `[Fail, Alloc, Live, Unit, Dst, List]` with six operands per
//! segment in the list.

use std::collections::HashMap;

use crate::atom::Atom;
use crate::error::ExecError;
use crate::interpreter::InstructionOutcome;
use crate::interpreter::opcodes::binary::{binary_op, heap_slice};
use crate::loader::decode::BinaryOp;
use crate::loader::decode::compact::Operand;
use crate::loader::{Instruction, Literal};
use crate::module::{Module, ModuleOrigin};
use crate::process::{CodePosition, Process};
use crate::term::Term;
use crate::term::binary::{packed_word_count, write_binary};
use crate::term::binary_ref::BinaryRef;

/// Arbitrary module-local atom indices standing in for segment type names
/// (`integer`, `binary`, `string`, `all`, ...) whose identities the handler
/// must not depend on.
const TYPE_INTEGER: u32 = 75;
const TYPE_BINARY: u32 = 71;
const TYPE_STRING: u32 = 73;
const ALL: u32 = 70;
const LITTLE: u32 = 92;

fn module(literals: Vec<Literal>, string_table: Vec<u8>) -> Module {
    let code = vec![Instruction::Label { label: 9 }];
    let constant_pool =
        crate::constant_pool::materialise_literals(&literals, None).expect("literal pool");
    Module {
        name: Atom::OK,
        generation: 0,
        origin: ModuleOrigin::Preloaded,
        exports: HashMap::new(),
        label_index: [(9, 0)].into_iter().collect(),
        code,
        literals,
        constant_pool,
        resolved_imports: Vec::new(),
        lambdas: Vec::new(),
        string_table,
        function_table: Vec::new(),
        line_table: Vec::new(),
        line_info: Vec::new(),
    }
}

fn binary_term(process: &mut Process, bytes: &[u8]) -> Term {
    let words = 2 + packed_word_count(bytes.len());
    let ptr = process.heap_mut().alloc(words).expect("test heap fits");
    let heap = heap_slice(ptr, words);
    write_binary(heap, bytes).expect("test binary fits")
}

fn atom(index: u32) -> Operand {
    Operand::Atom(Some(Atom::new(index)))
}

fn segment(
    type_atom: Operand,
    unit: u64,
    flags: Operand,
    source: Operand,
    size: Operand,
) -> Vec<Operand> {
    vec![
        type_atom,
        Operand::Unsigned(1),
        Operand::Unsigned(unit),
        flags,
        source,
        size,
    ]
}

fn create_bin(
    process: &mut Process,
    module: &Module,
    fail: u32,
    segments: Vec<Vec<Operand>>,
) -> Result<InstructionOutcome, ExecError> {
    let fields: Vec<Operand> = segments.into_iter().flatten().collect();
    binary_op(
        process,
        module,
        BinaryOp::BsCreateBin,
        &[
            Operand::Label(fail),
            Operand::Unsigned(0),
            Operand::Unsigned(1),
            Operand::Unsigned(1),
            Operand::X(0),
            Operand::List(fields),
        ],
    )
}

fn result_bytes(process: &Process) -> Vec<u8> {
    BinaryRef::new(process.x_reg(0))
        .expect("binary result")
        .as_bytes()
        .to_vec()
}

#[test]
fn bs_create_bin_integer_register_segment() {
    let mut process = Process::new(1, 64);
    let module = module(Vec::new(), Vec::new());
    process.set_x_reg(1, Term::small_int(65));
    let segments = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(8),
    )];
    assert_eq!(
        create_bin(&mut process, &module, 0, segments),
        Ok(InstructionOutcome::Continue)
    );
    assert_eq!(result_bytes(&process), vec![65]);
}

#[test]
fn bs_create_bin_integer_endianness_from_literal_flag_list() {
    let literals = vec![Literal::List(
        vec![Literal::Atom(Atom::new(LITTLE))],
        Box::new(Literal::Nil),
    )];
    let module = module(literals, Vec::new());

    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(0x4142));
    let little = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Literal(0),
        Operand::X(1),
        Operand::Integer(16),
    )];
    create_bin(&mut process, &module, 0, little).expect("little-endian segment");
    assert_eq!(result_bytes(&process), vec![0x42, 0x41]);

    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(0x4142));
    let big = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(16),
    )];
    create_bin(&mut process, &module, 0, big).expect("big-endian segment");
    assert_eq!(result_bytes(&process), vec![0x41, 0x42]);
}

#[test]
fn bs_create_bin_integer_truncates_and_sign_extends() {
    let module = module(Vec::new(), Vec::new());

    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(300));
    let truncated = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(8),
    )];
    create_bin(&mut process, &module, 0, truncated).expect("truncating segment");
    assert_eq!(result_bytes(&process), vec![44]);

    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(-2));
    let negative = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(16),
    )];
    create_bin(&mut process, &module, 0, negative).expect("negative segment");
    assert_eq!(result_bytes(&process), vec![0xff, 0xfe]);

    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(-1));
    let wide = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(128),
    )];
    create_bin(&mut process, &module, 0, wide).expect("sign-extended segment");
    assert_eq!(result_bytes(&process), vec![0xff; 16]);
}

#[test]
fn bs_create_bin_append_and_binary_all_segments_concatenate() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    let head = binary_term(&mut process, b"hello");
    let tail = binary_term(&mut process, b" world");
    process.set_x_reg(1, head);
    process.set_x_reg(2, tail);
    let segments = vec![
        segment(
            Operand::Atom(Some(Atom::APPEND)),
            8,
            Operand::Atom(None),
            Operand::X(1),
            atom(ALL),
        ),
        segment(
            atom(TYPE_BINARY),
            8,
            Operand::Atom(None),
            Operand::TypedRegister {
                register: Box::new(Operand::X(2)),
                type_index: 1,
            },
            atom(ALL),
        ),
    ];
    create_bin(&mut process, &module, 0, segments).expect("binary concat");
    assert_eq!(result_bytes(&process), b"hello world");
}

#[test]
fn bs_create_bin_string_table_segment() {
    let module = module(Vec::new(), b"lit!".to_vec());
    let mut process = Process::new(1, 64);
    let segments = vec![segment(
        atom(TYPE_STRING),
        8,
        Operand::Atom(None),
        Operand::Unsigned(0),
        Operand::Integer(3),
    )];
    create_bin(&mut process, &module, 0, segments).expect("string segment");
    assert_eq!(result_bytes(&process), b"lit");
}

#[test]
fn bs_create_bin_literal_binary_source_with_register_size() {
    let module = module(vec![Literal::Binary(b"abcdef".to_vec())], Vec::new());
    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(3));
    let segments = vec![segment(
        atom(TYPE_BINARY),
        8,
        Operand::Atom(None),
        Operand::Literal(0),
        Operand::X(1),
    )];
    create_bin(&mut process, &module, 0, segments).expect("literal prefix");
    assert_eq!(result_bytes(&process), b"abc");

    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(9));
    let segments = vec![segment(
        atom(TYPE_BINARY),
        8,
        Operand::Atom(None),
        Operand::Literal(0),
        Operand::X(1),
    )];
    assert_eq!(
        create_bin(&mut process, &module, 0, segments),
        Err(ExecError::Badarg)
    );
}

#[test]
fn bs_create_bin_sized_binary_register_source() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    let source = binary_term(&mut process, b"abcdef");
    process.set_x_reg(1, source);
    process.set_x_reg(2, Term::small_int(3));
    let segments = vec![segment(
        atom(TYPE_BINARY),
        8,
        Operand::Atom(None),
        Operand::X(1),
        Operand::X(2),
    )];
    create_bin(&mut process, &module, 0, segments).expect("sized binary");
    assert_eq!(result_bytes(&process), b"abc");
}

#[test]
fn bs_create_bin_utf8_segment_encodes_codepoint() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(0x20AC));
    let segments = vec![segment(
        Operand::Atom(Some(Atom::UTF8)),
        0,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Atom(Some(Atom::UNDEFINED)),
    )];
    create_bin(&mut process, &module, 0, segments).expect("utf8 segment");
    assert_eq!(result_bytes(&process), vec![0xe2, 0x82, 0xac]);
}

#[test]
fn bs_create_bin_utf8_surrogate_raises_badarg_or_jumps() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(0xD800));
    let surrogate = |process: &mut Process, fail| {
        create_bin(
            process,
            &module,
            fail,
            vec![segment(
                Operand::Atom(Some(Atom::UTF8)),
                0,
                Operand::Atom(None),
                Operand::X(1),
                Operand::Atom(Some(Atom::UNDEFINED)),
            )],
        )
    };
    assert_eq!(surrogate(&mut process, 0), Err(ExecError::Badarg));
    assert_eq!(
        surrogate(&mut process, 9),
        Ok(InstructionOutcome::Jump(CodePosition {
            module: Atom::OK,
            instruction_pointer: 0,
        }))
    );
}

#[test]
fn bs_create_bin_float_segments() {
    let module = module(
        vec![
            Literal::Float(1.5),
            Literal::List(
                vec![Literal::Atom(Atom::new(LITTLE))],
                Box::new(Literal::Nil),
            ),
        ],
        Vec::new(),
    );

    let mut process = Process::new(1, 64);
    let segments = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::Literal(0),
        Operand::Integer(64),
    )];
    create_bin(&mut process, &module, 0, segments).expect("float64 big");
    assert_eq!(result_bytes(&process), 1.5_f64.to_bits().to_be_bytes());

    let mut process = Process::new(1, 64);
    let segments = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Literal(1),
        Operand::Literal(0),
        Operand::Integer(32),
    )];
    create_bin(&mut process, &module, 0, segments).expect("float32 little");
    assert_eq!(result_bytes(&process), 1.5_f32.to_bits().to_le_bytes());
}

#[test]
fn bs_create_bin_bit_level_segments_pack_subbyte_values() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(5));
    let segments = vec![
        segment(
            atom(TYPE_INTEGER),
            1,
            Operand::Atom(None),
            Operand::X(1),
            Operand::Integer(3),
        ),
        segment(
            atom(TYPE_INTEGER),
            1,
            Operand::Atom(None),
            Operand::Integer(0),
            Operand::Integer(5),
        ),
    ];
    create_bin(&mut process, &module, 0, segments).expect("bit segments");
    assert_eq!(result_bytes(&process), vec![0b1010_0000]);
}

#[test]
fn bs_create_bin_non_byte_total_raises_badarg() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    process.set_x_reg(1, Term::small_int(5));
    let segments = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(3),
    )];
    assert_eq!(
        create_bin(&mut process, &module, 0, segments),
        Err(ExecError::Badarg)
    );
}

#[test]
fn bs_create_bin_non_numeric_source_raises_badarg() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    let segments = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::Atom(Some(Atom::OK)),
        Operand::Integer(8),
    )];
    assert_eq!(
        create_bin(&mut process, &module, 0, segments),
        Err(ExecError::Badarg)
    );
}

#[test]
fn bs_create_bin_collects_and_grows_when_heap_is_full() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 2);
    process.set_x_reg(1, Term::small_int(65));
    let segments = vec![segment(
        atom(TYPE_INTEGER),
        1,
        Operand::Atom(None),
        Operand::X(1),
        Operand::Integer(8),
    )];
    create_bin(&mut process, &module, 0, segments)
        .expect("create_bin grows the heap instead of failing");
    assert_eq!(result_bytes(&process), vec![65]);
}

#[test]
fn bs_create_bin_malformed_segment_list_is_invalid_operand() {
    let module = module(Vec::new(), Vec::new());
    let mut process = Process::new(1, 64);
    let result = binary_op(
        &mut process,
        &module,
        BinaryOp::BsCreateBin,
        &[
            Operand::Label(0),
            Operand::Unsigned(0),
            Operand::Unsigned(1),
            Operand::Unsigned(1),
            Operand::X(0),
            Operand::List(vec![Operand::Atom(None), Operand::Unsigned(1)]),
        ],
    );
    assert_eq!(
        result,
        Err(ExecError::InvalidOperand("bs_create_bin segment"))
    );
}