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bb2f9e9c PP |
1 | // Show ToC at a specific location for a GitHub rendering |
2 | ifdef::env-github[] | |
3 | :toc: macro | |
4 | endif::env-github[] | |
5 | ||
6 | ifndef::env-github[] | |
71aaa3f7 | 7 | :toc: left |
bb2f9e9c PP |
8 | endif::env-github[] |
9 | ||
10 | // This is to mimic what GitHub does so that anchors work in an offline | |
11 | // rendering too. | |
12 | :idprefix: | |
13 | :idseparator: - | |
71aaa3f7 | 14 | |
bb2f9e9c | 15 | // Other attributes |
71aaa3f7 PP |
16 | :py3: Python{nbsp}3 |
17 | ||
bb2f9e9c PP |
18 | = Normand |
19 | Philippe Proulx | |
20 | ||
df0f8552 PP |
21 | image::normand-logo.png[] |
22 | ||
71aaa3f7 PP |
23 | [.normal] |
24 | image:https://img.shields.io/pypi/v/normand.svg?label=Latest%20version[link="https://pypi.python.org/pypi/normand"] | |
25 | ||
26 | [.lead] | |
27 | _**Normand**_ is a text-to-binary processor with its own language. | |
28 | ||
29 | This package offers both a portable {py3} module and a command-line | |
30 | tool. | |
31 | ||
6dd69a2a | 32 | WARNING: This version of Normand is 0.16, meaning both the Normand |
71aaa3f7 PP |
33 | language and the module/CLI interface aren't stable. |
34 | ||
bb2f9e9c PP |
35 | ifdef::env-github[] |
36 | // ToC location for a GitHub rendering | |
37 | toc::[] | |
38 | endif::env-github[] | |
39 | ||
71aaa3f7 PP |
40 | == Introduction |
41 | ||
42 | The purpose of Normand is to consume human-readable text representing | |
43 | bytes and to produce the corresponding binary data. | |
44 | ||
45 | .Simple bytes input. | |
46 | ==== | |
47 | Consider the following Normand input: | |
48 | ||
49 | ---- | |
50 | 4f 55 32 bb $167 fe %10100111 a9 $-32 | |
51 | ---- | |
52 | ||
53 | The generated nine bytes are: | |
54 | ||
55 | ---- | |
56 | 4f 55 32 bb a7 fe a7 a9 e0 | |
57 | ---- | |
58 | ==== | |
59 | ||
60 | As you can see in the last example, the fundamental unit of the Normand | |
61 | language is the _byte_. The order in which you list bytes will be the | |
62 | order of the generated data. | |
63 | ||
64 | The Normand language is more than simple lists of bytes, though. Its | |
65 | main features are: | |
66 | ||
67 | Comments, including a bunch of insignificant symbols which may improve readability:: | |
68 | + | |
69 | Input: | |
70 | + | |
71 | ---- | |
72 | ff bb %1101:0010 # This is a comment | |
73 | 78 29 af $192 # This too # 99 $-80 | |
74 | fe80::6257:18ff:fea3:4229 | |
75 | 60:57:18:a3:42:29 | |
76 | 10839636-5d65-4a68-8e6a-21608ddf7258 | |
77 | ---- | |
78 | + | |
79 | Output: | |
80 | + | |
81 | ---- | |
82 | ff bb d2 78 29 af c0 99 b0 fe 80 62 57 18 ff fe | |
83 | a3 42 29 60 57 18 a3 42 29 10 83 96 36 5d 65 4a | |
84 | 68 8e 6a 21 60 8d df 72 58 | |
85 | ---- | |
86 | ||
87 | Hexadecimal, decimal, and binary byte constants:: | |
88 | + | |
89 | Input: | |
90 | + | |
91 | ---- | |
92 | aa bb $247 $-89 %0011_0010 %11.01= 10/10 | |
93 | ---- | |
94 | + | |
95 | Output: | |
96 | + | |
97 | ---- | |
98 | aa bb f7 a7 32 da | |
99 | ---- | |
100 | ||
101 | UTF-8, UTF-16, and UTF-32 literal strings:: | |
102 | + | |
103 | Input: | |
104 | + | |
105 | ---- | |
106 | "hello world!" 00 | |
107 | u16le"stress\nverdict 🤣" | |
108 | ---- | |
109 | + | |
110 | Output: | |
111 | + | |
112 | ---- | |
113 | 68 65 6c 6c 6f 20 77 6f 72 6c 64 21 00 73 00 74 ┆ hello world!•s•t | |
114 | 00 72 00 65 00 73 00 73 00 0a 00 76 00 65 00 72 ┆ •r•e•s•s•••v•e•r | |
115 | 00 64 00 69 00 63 00 74 00 20 00 3e d8 23 dd ┆ •d•i•c•t• •>•#• | |
116 | ---- | |
117 | ||
118 | Labels: special variables holding the offset where they're defined:: | |
119 | + | |
120 | ---- | |
121 | <beg> b2 52 e3 bc 91 05 | |
122 | $100 $50 <chair> 33 9f fe | |
123 | 25 e9 89 8a <end> | |
124 | ---- | |
125 | ||
126 | Variables:: | |
127 | + | |
128 | ---- | |
129 | 5e 65 {tower = 47} c6 7f f2 c4 | |
130 | 44 {hurl = tower - 14} b5 {tower = hurl} 26 2d | |
131 | ---- | |
132 | + | |
133 | The value of a variable assignment is the evaluation of a valid {py3} | |
134 | expression which may include label and variable names. | |
135 | ||
269f6eb3 | 136 | Fixed-length number with a given length (8{nbsp}bits to 64{nbsp}bits) and byte order:: |
71aaa3f7 PP |
137 | + |
138 | Input: | |
139 | + | |
140 | ---- | |
141 | {strength = 4} | |
142 | {be} 67 <lbl> 44 $178 {(end - lbl) * 8 + strength : 16} $99 <end> | |
143 | {le} {-1993 : 32} | |
269f6eb3 | 144 | {-3.141593 : 64} |
71aaa3f7 PP |
145 | ---- |
146 | + | |
147 | Output: | |
148 | + | |
149 | ---- | |
269f6eb3 PP |
150 | 67 44 b2 00 2c 63 37 f8 ff ff 7f bd c2 82 fb 21 |
151 | 09 c0 | |
71aaa3f7 PP |
152 | ---- |
153 | + | |
269f6eb3 | 154 | The encoded number is the evaluation of a valid {py3} expression which |
05f81895 PP |
155 | may include label and variable names. |
156 | ||
157 | https://en.wikipedia.org/wiki/LEB128[LEB128] integer:: | |
158 | + | |
159 | Input: | |
160 | + | |
161 | ---- | |
162 | aa bb cc {-1993 : sleb128} <meow> dd ee ff | |
163 | {meow * 199 : uleb128} | |
164 | ---- | |
165 | + | |
166 | Output: | |
167 | + | |
168 | ---- | |
169 | aa bb cc b7 70 dd ee ff e3 07 | |
170 | ---- | |
171 | + | |
172 | The encoded integer is the evaluation of a valid {py3} expression which | |
71aaa3f7 PP |
173 | may include label and variable names. |
174 | ||
27d52a19 PP |
175 | Conditional:: |
176 | + | |
177 | Input: | |
178 | + | |
179 | ---- | |
180 | aa bb cc | |
181 | ||
182 | ( | |
183 | "foo" | |
184 | ||
185 | !if {ICITTE > 10} | |
186 | "bar" | |
12b5dbc0 PP |
187 | !else |
188 | "fight" | |
27d52a19 PP |
189 | !end |
190 | ) * 4 | |
191 | ---- | |
192 | + | |
193 | Output: | |
194 | + | |
195 | ---- | |
12b5dbc0 PP |
196 | aa bb cc 66 6f 6f 66 69 67 68 74 66 6f 6f 66 69 ┆ •••foofightfoofi |
197 | 67 68 74 66 6f 6f 62 61 72 66 6f 6f 62 61 72 ┆ ghtfoobarfoobar | |
27d52a19 PP |
198 | ---- |
199 | ||
71aaa3f7 PP |
200 | Repetition:: |
201 | + | |
202 | Input: | |
203 | + | |
204 | ---- | |
2adf4336 | 205 | aa bb * 5 cc <zoom> "yeah\0" * {zoom * 3} |
e57a18e1 PP |
206 | |
207 | !repeat 3 | |
208 | ff ee "juice" | |
209 | !end | |
71aaa3f7 PP |
210 | ---- |
211 | + | |
212 | Output: | |
213 | + | |
214 | ---- | |
2adf4336 PP |
215 | aa bb bb bb bb bb cc 79 65 61 68 00 79 65 61 68 ┆ •••••••yeah•yeah |
216 | 00 79 65 61 68 00 79 65 61 68 00 79 65 61 68 00 ┆ •yeah•yeah•yeah• | |
217 | 79 65 61 68 00 79 65 61 68 00 79 65 61 68 00 79 ┆ yeah•yeah•yeah•y | |
218 | 65 61 68 00 79 65 61 68 00 79 65 61 68 00 79 65 ┆ eah•yeah•yeah•ye | |
219 | 61 68 00 79 65 61 68 00 79 65 61 68 00 79 65 61 ┆ ah•yeah•yeah•yea | |
220 | 68 00 79 65 61 68 00 79 65 61 68 00 79 65 61 68 ┆ h•yeah•yeah•yeah | |
71aaa3f7 | 221 | 00 79 65 61 68 00 79 65 61 68 00 79 65 61 68 00 ┆ •yeah•yeah•yeah• |
e57a18e1 PP |
222 | ff ee 6a 75 69 63 65 ff ee 6a 75 69 63 65 ff ee ┆ ••juice••juice•• |
223 | 6a 75 69 63 65 ┆ juice | |
71aaa3f7 PP |
224 | ---- |
225 | ||
676f6189 PP |
226 | Alignment:: |
227 | + | |
228 | Input: | |
229 | + | |
230 | ---- | |
231 | {be} | |
232 | ||
233 | {199:32} | |
234 | @64 {43:64} | |
235 | @16 {-123:16} | |
236 | @32~255 {5584:32} | |
237 | ---- | |
238 | + | |
239 | Output: | |
240 | + | |
241 | ---- | |
242 | 00 00 00 c7 00 00 00 00 00 00 00 00 00 00 00 2b | |
243 | ff 85 ff ff 00 00 15 d0 | |
244 | ---- | |
71aaa3f7 | 245 | |
25ca454b PP |
246 | Filling:: |
247 | + | |
248 | Input: | |
249 | + | |
250 | ---- | |
251 | {le} | |
252 | {0xdeadbeef:32} | |
253 | {-1993:16} | |
254 | {9:16} | |
255 | +0x40 | |
256 | {ICITTE:8} | |
257 | "meow mix" | |
fc21bb27 | 258 | +200~FFh |
25ca454b PP |
259 | {ICITTE:8} |
260 | ---- | |
261 | + | |
262 | Output: | |
263 | + | |
264 | ---- | |
265 | ef be ad de 37 f8 09 00 00 00 00 00 00 00 00 00 ┆ ••••7••••••••••• | |
266 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
267 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
268 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
269 | 40 6d 65 6f 77 20 6d 69 78 ff ff ff ff ff ff ff ┆ @meow mix••••••• | |
270 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
271 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
272 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
273 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
274 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
275 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
276 | ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ┆ •••••••••••••••• | |
277 | ff ff ff ff ff ff ff ff c8 ┆ ••••••••• | |
278 | ---- | |
279 | ||
71aaa3f7 PP |
280 | Multilevel grouping:: |
281 | + | |
282 | Input: | |
283 | + | |
284 | ---- | |
285 | ff ((aa bb "zoom" cc) * 5) * 3 $-34 * 4 | |
286 | ---- | |
287 | + | |
288 | Output: | |
289 | + | |
290 | ---- | |
291 | ff aa bb 7a 6f 6f 6d cc aa bb 7a 6f 6f 6d cc aa ┆ •••zoom•••zoom•• | |
292 | bb 7a 6f 6f 6d cc aa bb 7a 6f 6f 6d cc aa bb 7a ┆ •zoom•••zoom•••z | |
293 | 6f 6f 6d cc aa bb 7a 6f 6f 6d cc aa bb 7a 6f 6f ┆ oom•••zoom•••zoo | |
294 | 6d cc aa bb 7a 6f 6f 6d cc aa bb 7a 6f 6f 6d cc ┆ m•••zoom•••zoom• | |
295 | aa bb 7a 6f 6f 6d cc aa bb 7a 6f 6f 6d cc aa bb ┆ ••zoom•••zoom••• | |
296 | 7a 6f 6f 6d cc aa bb 7a 6f 6f 6d cc aa bb 7a 6f ┆ zoom•••zoom•••zo | |
297 | 6f 6d cc aa bb 7a 6f 6f 6d cc de de de de ┆ om•••zoom••••• | |
298 | ---- | |
299 | ||
320644e2 PP |
300 | Macros:: |
301 | + | |
302 | Input: | |
303 | + | |
304 | ---- | |
305 | !macro hello(world) | |
306 | "hello" | |
307 | !if world " world" !end | |
308 | !end | |
309 | ||
310 | !repeat 17 | |
311 | ff ff ff ff | |
312 | m:hello({ICITTE > 15 and ICITTE < 60}) | |
313 | !end | |
314 | ---- | |
315 | + | |
316 | Output: | |
317 | + | |
318 | ---- | |
319 | ff ff ff ff 68 65 6c 6c 6f ff ff ff ff 68 65 6c ┆ ••••hello••••hel | |
320 | 6c 6f ff ff ff ff 68 65 6c 6c 6f 20 77 6f 72 6c ┆ lo••••hello worl | |
321 | 64 ff ff ff ff 68 65 6c 6c 6f 20 77 6f 72 6c 64 ┆ d••••hello world | |
322 | ff ff ff ff 68 65 6c 6c 6f 20 77 6f 72 6c 64 ff ┆ ••••hello world• | |
323 | ff ff ff 68 65 6c 6c 6f ff ff ff ff 68 65 6c 6c ┆ •••hello••••hell | |
324 | 6f ff ff ff ff 68 65 6c 6c 6f ff ff ff ff 68 65 ┆ o••••hello••••he | |
325 | 6c 6c 6f ff ff ff ff 68 65 6c 6c 6f ff ff ff ff ┆ llo••••hello•••• | |
326 | 68 65 6c 6c 6f ff ff ff ff 68 65 6c 6c 6f ff ff ┆ hello••••hello•• | |
327 | ff ff 68 65 6c 6c 6f ff ff ff ff 68 65 6c 6c 6f ┆ ••hello••••hello | |
328 | ff ff ff ff 68 65 6c 6c 6f ff ff ff ff 68 65 6c ┆ ••••hello••••hel | |
329 | 6c 6f ff ff ff ff 68 65 6c 6c 6f ┆ lo••••hello | |
330 | ---- | |
331 | ||
71aaa3f7 PP |
332 | Precise error reporting:: |
333 | + | |
334 | ---- | |
335 | /tmp/meow.normand:10:24 - Expecting a bit (`0` or `1`). | |
336 | ---- | |
337 | + | |
338 | ---- | |
339 | /tmp/meow.normand:32:6 - Unexpected character `k`. | |
340 | ---- | |
341 | + | |
342 | ---- | |
320644e2 | 343 | /tmp/meow.normand:24:19 - Illegal (unknown or unreachable) variable/label name `meow` in expression `(meow - 45) // 8`; the legal names are {`ICITTE`, `mix`, `zoom`}. |
71aaa3f7 PP |
344 | ---- |
345 | + | |
346 | ---- | |
f5dcb24c PP |
347 | /tmp/meow.normand:32:19 - While expanding the macro `meow`: |
348 | /tmp/meow.normand:35:5 - While expanding the macro `zzz`: | |
320644e2 | 349 | /tmp/meow.normand:18:9 - Value 315 is outside the 8-bit range when evaluating expression `end - ICITTE`. |
71aaa3f7 PP |
350 | ---- |
351 | ||
352 | You can use Normand to track data source files in your favorite VCS | |
353 | instead of raw binary files. The binary files that Normand generates can | |
354 | be used to test file format decoding, including malformatted data, for | |
355 | example, as well as for education. | |
356 | ||
357 | See <<learn-normand>> to explore all the Normand features. | |
358 | ||
359 | == Install Normand | |
360 | ||
361 | Normand requires Python ≥ 3.4. | |
362 | ||
363 | To install Normand: | |
364 | ||
365 | ---- | |
366 | $ python3 -m pip install --user normand | |
367 | ---- | |
368 | ||
369 | See | |
370 | https://packaging.python.org/en/latest/tutorials/installing-packages/#installing-to-the-user-site[Installing to the User Site] | |
371 | to learn more about a user site installation. | |
372 | ||
373 | [NOTE] | |
374 | ==== | |
375 | Normand has a single module file, `normand.py`, which you can copy as is | |
af3cf417 | 376 | to your project to use it (both the <<python3-api,`normand.parse()`>> |
71aaa3f7 PP |
377 | function and the <<command-line-tool,command-line tool>>). |
378 | ||
379 | `normand.py` has _no external dependencies_, but if you're using | |
380 | Python{nbsp}3.4, you'll need a local copy of the standard `typing` | |
381 | module. | |
382 | ==== | |
383 | ||
43937a34 PP |
384 | == Design goals |
385 | ||
386 | The design goals of Normand are: | |
387 | ||
388 | Portability:: | |
389 | We're making sure `normand.py` works with Python{nbsp}≥{nbsp}3.4 and | |
390 | doesn't have any external dependencies so that you may just copy the | |
391 | module as is to your own project. | |
392 | ||
393 | Ease of use:: | |
394 | The most basic Normand input is a sequence of hexadecimal constants | |
395 | (for example, `4e6f726d616e64`) which produce exactly what you'd | |
396 | expect. | |
397 | + | |
398 | Most Normand features map to programming language concepts you already | |
399 | know and understand: constant integers, literal strings, variables, | |
400 | conditionals, repetitions/loops, and the rest. | |
401 | ||
402 | Concise and readable input:: | |
403 | We could have chosen XML or YAML as the input format, but having a | |
404 | DSL here makes a Normand input compact and easy to read, two | |
405 | important traits when using Normand to write tests, for example. | |
406 | + | |
407 | Compare the following Normand input and some hypothetical XML | |
408 | equivalent, for example: | |
409 | + | |
410 | .Actual normand input. | |
411 | ---- | |
412 | ff dd 01 ab $192 $-128 %1101:0011 | |
413 | ||
414 | {end:8} | |
415 | ||
416 | {iter = 1} | |
417 | ||
418 | !if {not something} | |
419 | # five times because xyz | |
420 | !repeat 5 | |
421 | "hello world " {iter:8} | |
422 | {iter = iter + 1} | |
423 | !end | |
424 | !end | |
425 | ||
426 | <end> | |
427 | ---- | |
428 | + | |
429 | .Hypothetical Normand XML input. | |
430 | [source,xml] | |
431 | ---- | |
432 | <?xml version="1.0" encoding="utf-8" ?> | |
433 | <group> | |
434 | <byte base="x" val="ff" /> | |
435 | <byte base="x" val="dd" /> | |
436 | <byte base="x" val="1" /> | |
437 | <byte base="x" val="ab" /> | |
438 | <byte base="d" val="192" /> | |
439 | <byte base="d" val="-128" /> | |
440 | <byte base="b" val="11010011" /> | |
441 | <fixed-len-num expr="end" len="8" /> | |
442 | <var-assign name="iter" expr="1" /> | |
443 | <cond expr="not something"> | |
444 | <!-- five times because xyz --> | |
445 | <repeat expr="5"> | |
446 | <str>hello world </str> | |
447 | <fixed-len-num expr="iter" len="8" /> | |
448 | <var-assign name="iter" expr="iter + 1" /> | |
449 | </repeat> | |
450 | </cond> | |
451 | <label name="end" /> | |
452 | </group> | |
453 | ---- | |
454 | ||
71aaa3f7 PP |
455 | == Learn Normand |
456 | ||
457 | A Normand text input is a sequence of items which represent a sequence | |
458 | of raw bytes. | |
459 | ||
460 | [[state]] During the processing of items to data, Normand relies on a | |
461 | current state: | |
462 | ||
463 | [%header%autowidth] | |
464 | |=== | |
af3cf417 | 465 | |State variable |Description |Initial value: <<python3-api,{py3} API>> |Initial value: <<command-line-tool,CLI>> |
71aaa3f7 PP |
466 | |
467 | |[[cur-offset]] Current offset | |
468 | | | |
05f81895 | 469 | The current offset has an effect on the value of <<label,labels>> and of |
269f6eb3 | 470 | the special `ICITTE` name in <<fixed-length-number,fixed-length |
27d52a19 | 471 | number>>, <<leb-128-integer,LEB128 integer>>, |
f63f4a5d | 472 | <<filling,filling>>, <<variable-assignment,variable assignment>>, |
27d52a19 | 473 | <<conditional-block,conditional block>>, <<repetition-block,repetition |
320644e2 PP |
474 | block>>, <<macro-expansion,macro expansion>>, and |
475 | <<post-item-repetition,post-item repetition>> expression evaluation. | |
71aaa3f7 PP |
476 | |
477 | Each generated byte increments the current offset. | |
478 | ||
479 | A <<current-offset-setting,current offset setting>> may change the | |
676f6189 PP |
480 | current offset without generating data. |
481 | ||
482 | An <<current-offset-alignment,current offset alignment>> generates | |
483 | padding bytes to make the current offset satisfy a given alignment. | |
71aaa3f7 PP |
484 | |`init_offset` parameter of the `parse()` function. |
485 | |`--offset` option. | |
486 | ||
487 | |[[cur-bo]] Current byte order | |
488 | | | |
05f81895 | 489 | The current byte order has an effect on the encoding of |
269f6eb3 | 490 | <<fixed-length-number,fixed-length numbers>>. |
71aaa3f7 PP |
491 | |
492 | A <<current-byte-order-setting,current byte order setting>> may change | |
493 | the current byte order. | |
494 | |`init_byte_order` parameter of the `parse()` function. | |
495 | |`--byte-order` option. | |
496 | ||
497 | |<<label,Labels>> | |
498 | |Mapping of label names to integral values. | |
499 | |`init_labels` parameter of the `parse()` function. | |
500 | |One or more `--label` options. | |
501 | ||
502 | |<<variable-assignment,Variables>> | |
27d52a19 | 503 | |Mapping of variable names to integral or floating point number values. |
71aaa3f7 PP |
504 | |`init_variables` parameter of the `parse()` function. |
505 | |One or more `--var` options. | |
506 | |=== | |
507 | ||
508 | The available items are: | |
509 | ||
6dd69a2a PP |
510 | * A <<byte-constant,constant integer>> representing one or more |
511 | constant bytes. | |
71aaa3f7 PP |
512 | |
513 | * A <<literal-string,literal string>> representing a sequence of bytes | |
514 | encoding UTF-8, UTF-16, or UTF-32 data. | |
515 | ||
516 | * A <<current-byte-order-setting,current byte order setting>> (big or | |
517 | little endian). | |
518 | ||
269f6eb3 PP |
519 | * A <<fixed-length-number,fixed-length number>> (integer or |
520 | floating point) using the <<cur-bo,current byte order>> and of which | |
521 | the value is the result of a {py3} expression. | |
05f81895 PP |
522 | |
523 | * An <<leb128-integer,LEB128 integer>> of which the value is the result | |
524 | of a {py3} expression. | |
71aaa3f7 PP |
525 | |
526 | * A <<current-offset-setting,current offset setting>>. | |
527 | ||
676f6189 PP |
528 | * A <<current-offset-alignment,current offset alignment>>. |
529 | ||
25ca454b PP |
530 | * A <<filling,filling>>. |
531 | ||
71aaa3f7 PP |
532 | * A <<label,label>>, that is, a named constant holding the current |
533 | offset. | |
534 | + | |
535 | This is similar to an assembly label. | |
536 | ||
537 | * A <<variable-assignment,variable assignment>> associating a name to | |
538 | the integral result of an evaluated {py3} expression. | |
539 | ||
540 | * A <<group,group>>, that is, a scoped sequence of items. | |
541 | ||
27d52a19 PP |
542 | * A <<conditional-block,conditional block>>. |
543 | ||
e57a18e1 PP |
544 | * A <<repetition-block,repetition block>>. |
545 | ||
320644e2 PP |
546 | * A <<macro-definition-block,macro definition block>>. |
547 | ||
548 | * A <<macro-expansion,macro expansion>>. | |
549 | ||
e57a18e1 PP |
550 | Moreover, you can repeat many items above a constant or variable number |
551 | of times with the ``pass:[*]`` operator _after_ the item to repeat. This | |
552 | is called a <<post-item-repetition,post-item repetition>>. | |
71aaa3f7 PP |
553 | |
554 | A Normand comment may exist: | |
555 | ||
556 | * Between items, possibly within a group. | |
557 | * Between the nibbles of a constant hexadecimal byte. | |
558 | * Between the bits of a constant binary byte. | |
e57a18e1 PP |
559 | * Between the last item and the ``pass:[*]`` character of a post-item |
560 | repetition, and between that ``pass:[*]`` character and the following | |
561 | number or expression. | |
261c5ecf PP |
562 | * Between the ``!repeat``/``!r`` block opening and the following |
563 | constant integer, name, or expression of a repetition block. | |
564 | * Between the ``!if`` block opening and the following name or expression | |
565 | of a conditional block. | |
71aaa3f7 PP |
566 | |
567 | A comment is anything between two ``pass:[#]`` characters on the same | |
568 | line, or from ``pass:[#]`` until the end of the line. Whitespaces and | |
569 | the following symbol characters are also considered comments where a | |
570 | comment may exist: | |
571 | ||
572 | ---- | |
25ca454b | 573 | / \ ? & : ; . , [ ] _ = | - |
71aaa3f7 PP |
574 | ---- |
575 | ||
576 | The latter serve to improve readability so that you may write, for | |
577 | example, a MAC address or a UUID as is. | |
578 | ||
fc21bb27 PP |
579 | [[const-int]] Many items require a _constant integer_, possibly |
580 | negative, in which case it may start with `-` for a negative integer. A | |
581 | positive constant integer is any of: | |
582 | ||
583 | Decimal:: | |
584 | One or mode digits (`0` to `9`). | |
585 | ||
586 | Hexadecimal:: | |
587 | One of: | |
588 | + | |
589 | * The `0x` or `0X` prefix followed with one or more hexadecimal digits | |
590 | (`0` to `9`, `a` to `f`, or `A` to `F`). | |
591 | * One or more hexadecimal digits followed with the `h` or `H` suffix. | |
592 | ||
593 | Octal:: | |
594 | One of: | |
595 | + | |
596 | * The `0o` or `0O` prefix followed with one or more octal digits | |
597 | (`0` to `7`). | |
598 | * One or more octal digits followed with the `o`, `O`, `q`, or `Q` | |
599 | suffix. | |
600 | ||
601 | Binary:: | |
602 | One of: | |
603 | + | |
604 | * The `0b` or `0B` prefix followed with one or more bits (`0` or `1`). | |
605 | * One or more bits followed with the `b` or `B` suffix. | |
606 | ||
71aaa3f7 PP |
607 | You can test the examples of this section with the `normand` |
608 | <<command-line-tool,command-line tool>> as such: | |
609 | ||
610 | ---- | |
611 | $ normand file | hexdump -C | |
612 | ---- | |
613 | ||
614 | where `file` is the name of a file containing the Normand input. | |
615 | ||
616 | === Byte constant | |
617 | ||
6dd69a2a | 618 | A _byte constant_ represents one or more constant bytes. |
71aaa3f7 PP |
619 | |
620 | A byte constant is: | |
621 | ||
622 | Hexadecimal form:: | |
6dd69a2a | 623 | Two consecutive hexadecimal digits representing a single byte. |
71aaa3f7 PP |
624 | |
625 | Decimal form:: | |
6dd69a2a | 626 | One or more digits after the `$` prefix representing a single byte. |
71aaa3f7 | 627 | |
6dd69a2a PP |
628 | Binary form:: {empty} |
629 | + | |
630 | -- | |
631 | . __**N**__ `%` prefixes (at least one). | |
632 | + | |
633 | The number of `%` characters is the number of subsequent expected bytes. | |
634 | ||
635 | . __**N**__{nbsp}×{nbsp}8 bits (`0` or `1`). | |
636 | -- | |
71aaa3f7 PP |
637 | |
638 | ==== | |
639 | Input: | |
640 | ||
641 | ---- | |
642 | ab cd [3d 8F] CC | |
643 | ---- | |
644 | ||
645 | Output: | |
646 | ||
647 | ---- | |
648 | ab cd 3d 8f cc | |
649 | ---- | |
650 | ==== | |
651 | ||
652 | ==== | |
653 | Input: | |
654 | ||
655 | ---- | |
656 | $192 %1100/0011 $ -77 | |
657 | ---- | |
658 | ||
659 | Output: | |
660 | ||
661 | ---- | |
662 | c0 c3 b3 | |
663 | ---- | |
664 | ==== | |
665 | ||
666 | ==== | |
667 | Input: | |
668 | ||
669 | ---- | |
670 | 58f64689-6316-4d55-8a1a-04cada366172 | |
671 | fe80::6257:18ff:fea3:4229 | |
672 | ---- | |
673 | ||
674 | Output: | |
675 | ||
676 | ---- | |
677 | 58 f6 46 89 63 16 4d 55 8a 1a 04 ca da 36 61 72 ┆ X•F•c•MU•••••6ar | |
678 | fe 80 62 57 18 ff fe a3 42 29 ┆ ••bW••••B) | |
679 | ---- | |
680 | ==== | |
681 | ||
682 | ==== | |
683 | Input: | |
684 | ||
685 | ---- | |
686 | %01110011 %01100001 %01101100 %01110101 %01110100 | |
6dd69a2a | 687 | %%%1101:0010 11111111 #A#11 #B#00 #C#011 #D#1 |
71aaa3f7 PP |
688 | ---- |
689 | ||
690 | Output: | |
691 | ||
692 | ---- | |
6dd69a2a | 693 | 73 61 6c 75 74 d2 ff c7 ┆ salut••• |
71aaa3f7 PP |
694 | ---- |
695 | ==== | |
696 | ||
697 | === Literal string | |
698 | ||
699 | A _literal string_ represents the UTF-8-, UTF-16-, or UTF-32-encoded | |
700 | bytes of a string. | |
701 | ||
702 | The string to encode isn't implicitly null-terminated: use `\0` at the | |
703 | end of the string to add a null character. | |
704 | ||
705 | A literal string is: | |
706 | ||
707 | . **Optional**: one of the following encodings instead of UTF-8: | |
708 | + | |
709 | -- | |
710 | [horizontal] | |
711 | `u16be`:: UTF-16BE. | |
712 | `u16le`:: UTF-16LE. | |
713 | `u32be`:: UTF-32BE. | |
714 | `u32le`:: UTF-32LE. | |
715 | -- | |
716 | ||
717 | . The ``pass:["]`` prefix. | |
718 | ||
719 | . A sequence of zero or more characters, possibly containing escape | |
720 | sequences. | |
721 | + | |
722 | An escape sequence is the ``\`` character followed by one of: | |
723 | + | |
724 | -- | |
725 | [horizontal] | |
726 | `0`:: Null (U+0000) | |
727 | `a`:: Alert (U+0007) | |
728 | `b`:: Backspace (U+0008) | |
729 | `e`:: Escape (U+001B) | |
730 | `f`:: Form feed (U+000C) | |
731 | `n`:: End of line (U+000A) | |
732 | `r`:: Carriage return (U+000D) | |
733 | `t`:: Character tabulation (U+0009) | |
734 | `v`:: Line tabulation (U+000B) | |
735 | ``\``:: Reverse solidus (U+005C) | |
736 | ``pass:["]``:: Quotation mark (U+0022) | |
737 | -- | |
738 | ||
739 | . The ``pass:["]`` suffix. | |
740 | ||
741 | ==== | |
742 | Input: | |
743 | ||
744 | ---- | |
745 | "coucou tout le monde!" | |
746 | ---- | |
747 | ||
748 | Output: | |
749 | ||
750 | ---- | |
751 | 63 6f 75 63 6f 75 20 74 6f 75 74 20 6c 65 20 6d ┆ coucou tout le m | |
752 | 6f 6e 64 65 21 ┆ onde! | |
753 | ---- | |
754 | ==== | |
755 | ||
756 | ==== | |
757 | Input: | |
758 | ||
759 | ---- | |
760 | u16le"I am not young enough to know everything." | |
761 | ---- | |
762 | ||
763 | Output: | |
764 | ||
765 | ---- | |
766 | 49 00 20 00 61 00 6d 00 20 00 6e 00 6f 00 74 00 ┆ I• •a•m• •n•o•t• | |
767 | 20 00 79 00 6f 00 75 00 6e 00 67 00 20 00 65 00 ┆ •y•o•u•n•g• •e• | |
768 | 6e 00 6f 00 75 00 67 00 68 00 20 00 74 00 6f 00 ┆ n•o•u•g•h• •t•o• | |
769 | 20 00 6b 00 6e 00 6f 00 77 00 20 00 65 00 76 00 ┆ •k•n•o•w• •e•v• | |
770 | 65 00 72 00 79 00 74 00 68 00 69 00 6e 00 67 00 ┆ e•r•y•t•h•i•n•g• | |
771 | 2e 00 ┆ .• | |
772 | ---- | |
773 | ==== | |
774 | ||
775 | ==== | |
776 | Input: | |
777 | ||
778 | ---- | |
779 | u32be "\"illusion is the first\nof all pleasures\" 🦉" | |
780 | ---- | |
781 | ||
782 | Output: | |
783 | ||
784 | ---- | |
785 | 00 00 00 22 00 00 00 69 00 00 00 6c 00 00 00 6c ┆ •••"•••i•••l•••l | |
786 | 00 00 00 75 00 00 00 73 00 00 00 69 00 00 00 6f ┆ •••u•••s•••i•••o | |
787 | 00 00 00 6e 00 00 00 20 00 00 00 69 00 00 00 73 ┆ •••n••• •••i•••s | |
788 | 00 00 00 20 00 00 00 74 00 00 00 68 00 00 00 65 ┆ ••• •••t•••h•••e | |
789 | 00 00 00 20 00 00 00 66 00 00 00 69 00 00 00 72 ┆ ••• •••f•••i•••r | |
790 | 00 00 00 73 00 00 00 74 00 00 00 0a 00 00 00 6f ┆ •••s•••t•••••••o | |
791 | 00 00 00 66 00 00 00 20 00 00 00 61 00 00 00 6c ┆ •••f••• •••a•••l | |
792 | 00 00 00 6c 00 00 00 20 00 00 00 70 00 00 00 6c ┆ •••l••• •••p•••l | |
793 | 00 00 00 65 00 00 00 61 00 00 00 73 00 00 00 75 ┆ •••e•••a•••s•••u | |
794 | 00 00 00 72 00 00 00 65 00 00 00 73 00 00 00 22 ┆ •••r•••e•••s•••" | |
795 | 00 00 00 20 00 01 f9 89 ┆ ••• •••• | |
796 | ---- | |
797 | ==== | |
798 | ||
799 | === Current byte order setting | |
800 | ||
801 | This special item sets the <<cur-bo,_current byte order_>>. | |
802 | ||
803 | The two accepted forms are: | |
804 | ||
805 | [horizontal] | |
806 | ``pass:[{be}]``:: Set the current byte order to big endian. | |
807 | ``pass:[{le}]``:: Set the current byte order to little endian. | |
808 | ||
269f6eb3 | 809 | === Fixed-length number |
71aaa3f7 | 810 | |
269f6eb3 PP |
811 | A _fixed-length number_ represents a fixed number of bytes encoding |
812 | either: | |
813 | ||
814 | * An unsigned or signed integer (two's complement). | |
815 | + | |
816 | The available lengths are 8, 16, 24, 32, 40, 48, 56, and 64. | |
817 | ||
818 | * A floating point number | |
b87a3aa2 | 819 | (https://standards.ieee.org/standard/754-2008.html[IEEE{nbsp}754-2008]). |
269f6eb3 PP |
820 | + |
821 | The available length are 32 (_binary32_) and 64 (_binary64_). | |
71aaa3f7 | 822 | |
269f6eb3 PP |
823 | The value is the result of evaluating a {py3} expression using the |
824 | <<cur-bo,current byte order>>. | |
825 | ||
826 | A fixed-length number is: | |
71aaa3f7 PP |
827 | |
828 | . The ``pass:[{]`` prefix. | |
829 | ||
830 | . A valid {py3} expression. | |
05f81895 | 831 | + |
269f6eb3 | 832 | For a fixed-length number at some source location{nbsp}__**L**__, this |
05f81895 PP |
833 | expression may contain the name of any accessible <<label,label>> (not |
834 | within a nested group), including the name of a label defined | |
835 | after{nbsp}__**L**__, as well as the name of any | |
836 | <<variable-assignment,variable>> known at{nbsp}__**L**__. | |
837 | + | |
269f6eb3 PP |
838 | The value of the special name `ICITTE` (`int` type) in this expression |
839 | is the <<cur-offset,current offset>> (before encoding the number). | |
71aaa3f7 PP |
840 | |
841 | . The `:` character. | |
842 | ||
269f6eb3 PP |
843 | . An encoding length in bits amongst: |
844 | + | |
845 | -- | |
27d52a19 | 846 | The expression evaluates to an `int` or `bool` value:: |
269f6eb3 | 847 | `8`, `16`, `24`, `32`, `40`, `48`, `56`, and `64`. |
27d52a19 PP |
848 | + |
849 | NOTE: Normand automatically converts a `bool` value to `int`. | |
269f6eb3 PP |
850 | |
851 | The expression evaluates to a `float` value:: | |
852 | `32` and `64`. | |
853 | -- | |
71aaa3f7 PP |
854 | |
855 | . The `}` suffix. | |
856 | ||
857 | ==== | |
858 | Input: | |
859 | ||
860 | ---- | |
861 | {le} {345:16} | |
862 | {be} {-0xabcd:32} | |
863 | ---- | |
864 | ||
865 | Output: | |
866 | ||
867 | ---- | |
868 | 59 01 ff ff 54 33 | |
869 | ---- | |
870 | ==== | |
871 | ||
872 | ==== | |
873 | Input: | |
874 | ||
875 | ---- | |
876 | {be} | |
877 | ||
878 | # String length in bits | |
879 | {8 * (str_end - str_beg) : 16} | |
880 | ||
881 | # String | |
882 | <str_beg> | |
883 | "hello world!" | |
884 | <str_end> | |
885 | ---- | |
886 | ||
887 | Output: | |
888 | ||
889 | ---- | |
890 | 00 60 68 65 6c 6c 6f 20 77 6f 72 6c 64 21 ┆ •`hello world! | |
891 | ---- | |
892 | ==== | |
893 | ||
894 | ==== | |
895 | Input: | |
896 | ||
897 | ---- | |
898 | {20 - ICITTE : 8} * 10 | |
899 | ---- | |
900 | ||
901 | Output: | |
902 | ||
903 | ---- | |
904 | 14 13 12 11 10 0f 0e 0d 0c 0b | |
905 | ---- | |
906 | ==== | |
907 | ||
269f6eb3 PP |
908 | ==== |
909 | Input: | |
910 | ||
911 | ---- | |
912 | {le} | |
913 | {2 * 0.0529 : 32} | |
914 | ---- | |
915 | ||
916 | Output: | |
917 | ||
918 | ---- | |
919 | ac ad d8 3d | |
920 | ---- | |
921 | ==== | |
922 | ||
05f81895 PP |
923 | === LEB128 integer |
924 | ||
925 | An _LEB128 integer_ represents a variable number of bytes encoding an | |
926 | unsigned or signed integer which is the result of evaluating a {py3} | |
927 | expression following the https://en.wikipedia.org/wiki/LEB128[LEB128] | |
928 | format. | |
929 | ||
930 | An LEB128 integer is: | |
931 | ||
932 | . The ``pass:[{]`` prefix. | |
933 | ||
27d52a19 PP |
934 | . A valid {py3} expression of which the evaluation result type |
935 | is `int` or `bool` (automatically converted to `int`). | |
05f81895 PP |
936 | + |
937 | For an LEB128 integer at some source location{nbsp}__**L**__, this | |
938 | expression may contain: | |
939 | + | |
940 | -- | |
fc21bb27 PP |
941 | * The name of any <<label,label>> defined before{nbsp}__**L**__ |
942 | which isn't within a nested group. | |
320644e2 PP |
943 | * The name of any <<variable-assignment,variable>> known |
944 | at{nbsp}__**L**__. | |
05f81895 PP |
945 | -- |
946 | + | |
269f6eb3 PP |
947 | The value of the special name `ICITTE` (`int` type) in this expression |
948 | is the <<cur-offset,current offset>> (before encoding the integer). | |
05f81895 PP |
949 | |
950 | . The `:` character. | |
951 | ||
952 | . One of: | |
953 | + | |
954 | -- | |
955 | [horizontal] | |
956 | `uleb128`:: Use the unsigned LEB128 format. | |
957 | `sleb128`:: Use the signed LEB128 format. | |
958 | -- | |
959 | ||
960 | . The `}` suffix. | |
961 | ||
962 | ==== | |
963 | Input: | |
964 | ||
965 | ---- | |
966 | {624485 : uleb128} | |
967 | ---- | |
968 | ||
969 | Output: | |
970 | ||
971 | ---- | |
972 | e5 8e 26 | |
973 | ---- | |
974 | ==== | |
975 | ||
976 | ==== | |
977 | Input: | |
978 | ||
979 | ---- | |
980 | aa bb cc dd | |
981 | <meow> | |
982 | ee ff | |
983 | {-981238311 + (meow * -23) : sleb128} | |
984 | "hello" | |
985 | ---- | |
986 | ||
c2b79cf6 PP |
987 | Output: |
988 | ||
05f81895 PP |
989 | ---- |
990 | aa bb cc dd ee ff fd fa 8d ac 7c 68 65 6c 6c 6f ┆ ••••••••••|hello | |
991 | ---- | |
992 | ==== | |
993 | ||
71aaa3f7 PP |
994 | === Current offset setting |
995 | ||
996 | This special item sets the <<cur-offset,_current offset_>>. | |
997 | ||
998 | A current offset setting is: | |
999 | ||
1000 | . The `<` prefix. | |
1001 | ||
fc21bb27 PP |
1002 | . A <<const-int,positive constant integer>> which is the new current |
1003 | offset. | |
71aaa3f7 PP |
1004 | |
1005 | . The `>` suffix. | |
1006 | ||
1007 | ==== | |
1008 | Input: | |
1009 | ||
1010 | ---- | |
1011 | {ICITTE : 8} * 8 | |
1012 | <0x61> {ICITTE : 8} * 8 | |
1013 | ---- | |
1014 | ||
1015 | Output: | |
1016 | ||
1017 | ---- | |
1018 | 00 01 02 03 04 05 06 07 61 62 63 64 65 66 67 68 ┆ ••••••••abcdefgh | |
1019 | ---- | |
1020 | ==== | |
1021 | ||
1022 | ==== | |
1023 | Input: | |
1024 | ||
1025 | ---- | |
1026 | aa bb cc dd <meow> ee ff | |
1027 | <12> 11 22 33 <mix> 44 55 | |
1028 | {meow : 8} {mix : 8} | |
1029 | ---- | |
1030 | ||
1031 | Output: | |
1032 | ||
1033 | ---- | |
1034 | aa bb cc dd ee ff 11 22 33 44 55 04 0f ┆ •••••••"3DU•• | |
1035 | ---- | |
1036 | ==== | |
1037 | ||
676f6189 PP |
1038 | === Current offset alignment |
1039 | ||
00deb9fa | 1040 | A _current offset alignment_ represents zero or more padding bytes to |
676f6189 PP |
1041 | make the <<cur-offset,current offset>> meet a given |
1042 | https://en.wikipedia.org/wiki/Data_structure_alignment[alignment] value. | |
1043 | ||
1044 | More specifically, for an alignment value of{nbsp}__**N**__{nbsp}bits, | |
1045 | a current offset alignment represents the required padding bytes until | |
1046 | the current offset is a multiple of __**N**__{nbsp}/{nbsp}8. | |
1047 | ||
1048 | A current offset alignment is: | |
1049 | ||
1050 | . The `@` prefix. | |
1051 | ||
fc21bb27 PP |
1052 | . A <<const-int,positive constant integer>> which is the alignment value |
1053 | in _bits_. | |
676f6189 PP |
1054 | + |
1055 | This value must be greater than zero and a multiple of{nbsp}8. | |
1056 | ||
1057 | . **Optional**: | |
1058 | + | |
1059 | -- | |
1060 | . The ``pass:[~]`` prefix. | |
fc21bb27 PP |
1061 | . A <<const-int,positive constant integer>> which is the value of the |
1062 | byte to use as padding to align the <<cur-offset,current offset>>. | |
676f6189 PP |
1063 | -- |
1064 | + | |
1065 | Without this section, the padding byte value is zero. | |
1066 | ||
1067 | ==== | |
1068 | Input: | |
1069 | ||
1070 | ---- | |
1071 | 11 22 (@32 aa bb cc) * 3 | |
1072 | ---- | |
1073 | ||
1074 | Output: | |
1075 | ||
1076 | ---- | |
1077 | 11 22 00 00 aa bb cc 00 aa bb cc 00 aa bb cc | |
1078 | ---- | |
1079 | ==== | |
1080 | ||
1081 | ==== | |
1082 | Input: | |
1083 | ||
1084 | ---- | |
1085 | {le} | |
1086 | 77 88 | |
1087 | @32~0xcc {-893.5:32} | |
1088 | @128~0x55 "meow" | |
1089 | ---- | |
1090 | ||
1091 | Output: | |
1092 | ||
1093 | ---- | |
1094 | 77 88 cc cc 00 60 5f c4 55 55 55 55 55 55 55 55 ┆ w••••`_•UUUUUUUU | |
1095 | 6d 65 6f 77 ┆ meow | |
1096 | ---- | |
1097 | ==== | |
1098 | ||
1099 | ==== | |
1100 | Input: | |
1101 | ||
1102 | ---- | |
1103 | aa bb cc <29> @64~255 "zoom" | |
1104 | ---- | |
1105 | ||
1106 | Output: | |
1107 | ||
1108 | ---- | |
1109 | aa bb cc ff ff ff 7a 6f 6f 6d ┆ ••••••zoom | |
1110 | ---- | |
1111 | ==== | |
1112 | ||
25ca454b PP |
1113 | === Filling |
1114 | ||
1115 | A _filling_ represents zero or more padding bytes to make the | |
1116 | <<cur-offset,current offset>> reach a given value. | |
1117 | ||
1118 | A filling is: | |
1119 | ||
1120 | . The ``pass:[+]`` prefix. | |
1121 | ||
1122 | . One of: | |
1123 | ||
fc21bb27 PP |
1124 | ** A <<const-int,positive constant integer>> which is the current offset |
1125 | target. | |
25ca454b PP |
1126 | |
1127 | ** The ``pass:[{]`` prefix, a valid {py3} expression of which the | |
1128 | evaluation result type is `int` or `bool` (automatically converted to | |
1129 | `int`), and the ``pass:[}]`` suffix. | |
1130 | + | |
1131 | For a filling at some source location{nbsp}__**L**__, this expression | |
1132 | may contain: | |
1133 | + | |
1134 | -- | |
1135 | * The name of any <<label,label>> defined before{nbsp}__**L**__ | |
1136 | which isn't within a nested group. | |
1137 | * The name of any <<variable-assignment,variable>> known | |
1138 | at{nbsp}__**L**__. | |
1139 | -- | |
1140 | + | |
1141 | The value of the special name `ICITTE` (`int` type) in this expression | |
1142 | is the <<cur-offset,current offset>> (before handling the items to | |
1143 | repeat). | |
1144 | ||
1145 | ** A valid {py3} name. | |
1146 | + | |
1147 | For the name `__NAME__`, this is equivalent to the | |
1148 | `pass:[{]__NAME__pass:[}]` form above. | |
1149 | ||
1150 | + | |
1151 | This value must be greater than or equal to the current offset where | |
1152 | it's used. | |
1153 | ||
1154 | . **Optional**: | |
1155 | + | |
1156 | -- | |
1157 | . The ``pass:[~]`` prefix. | |
fc21bb27 PP |
1158 | . A <<const-int,positive constant integer>> which is the value of the |
1159 | byte to use as padding to reach the current offset target. | |
25ca454b PP |
1160 | -- |
1161 | + | |
1162 | Without this section, the padding byte value is zero. | |
1163 | ||
1164 | ==== | |
1165 | Input: | |
1166 | ||
1167 | ---- | |
1168 | aa bb cc dd | |
1169 | +0x40 | |
1170 | "hello world" | |
1171 | ---- | |
1172 | ||
1173 | Output: | |
1174 | ||
1175 | ---- | |
1176 | aa bb cc dd 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
1177 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
1178 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
1179 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ┆ •••••••••••••••• | |
1180 | 68 65 6c 6c 6f 20 77 6f 72 6c 64 ┆ hello world | |
1181 | ---- | |
1182 | ==== | |
1183 | ||
1184 | ==== | |
1185 | Input: | |
1186 | ||
1187 | ---- | |
1188 | !macro part(iter, fill) | |
1189 | <0> "particular security " {ord('0') + iter : 8} +fill~0x80 | |
1190 | !end | |
1191 | ||
1192 | {iter = 1} | |
1193 | ||
1194 | !repeat 5 | |
1195 | m:part(iter, {32 + 4 * iter}) | |
1196 | {iter = iter + 1} | |
1197 | !end | |
1198 | ---- | |
1199 | ||
1200 | Output: | |
1201 | ||
1202 | ---- | |
1203 | 70 61 72 74 69 63 75 6c 61 72 20 73 65 63 75 72 ┆ particular secur | |
1204 | 69 74 79 20 31 80 80 80 80 80 80 80 80 80 80 80 ┆ ity 1••••••••••• | |
1205 | 80 80 80 80 70 61 72 74 69 63 75 6c 61 72 20 73 ┆ ••••particular s | |
1206 | 65 63 75 72 69 74 79 20 32 80 80 80 80 80 80 80 ┆ ecurity 2••••••• | |
1207 | 80 80 80 80 80 80 80 80 80 80 80 80 70 61 72 74 ┆ ••••••••••••part | |
1208 | 69 63 75 6c 61 72 20 73 65 63 75 72 69 74 79 20 ┆ icular security | |
1209 | 33 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 ┆ 3••••••••••••••• | |
1210 | 80 80 80 80 80 80 80 80 70 61 72 74 69 63 75 6c ┆ ••••••••particul | |
1211 | 61 72 20 73 65 63 75 72 69 74 79 20 34 80 80 80 ┆ ar security 4••• | |
1212 | 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 ┆ •••••••••••••••• | |
1213 | 80 80 80 80 80 80 80 80 70 61 72 74 69 63 75 6c ┆ ••••••••particul | |
1214 | 61 72 20 73 65 63 75 72 69 74 79 20 35 80 80 80 ┆ ar security 5••• | |
1215 | 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 ┆ •••••••••••••••• | |
1216 | 80 80 80 80 80 80 80 80 80 80 80 80 ┆ •••••••••••• | |
1217 | ---- | |
1218 | ==== | |
1219 | ||
71aaa3f7 PP |
1220 | === Label |
1221 | ||
1222 | A _label_ associates a name to the <<cur-offset,current offset>>. | |
1223 | ||
1224 | All the labels of a whole Normand input must have unique names. | |
1225 | ||
05f81895 | 1226 | A label must not share the name of a <<variable-assignment,variable>> |
71aaa3f7 PP |
1227 | name. |
1228 | ||
71aaa3f7 PP |
1229 | A label is: |
1230 | ||
1231 | . The `<` prefix. | |
1232 | ||
27d52a19 | 1233 | . A valid {py3} name which is not `ICITTE`. |
71aaa3f7 PP |
1234 | |
1235 | . The `>` suffix. | |
1236 | ||
1237 | === Variable assignment | |
1238 | ||
1239 | A _variable assignment_ associates a name to the integral result of an | |
1240 | evaluated {py3} expression. | |
1241 | ||
05f81895 | 1242 | A variable assignment is: |
71aaa3f7 PP |
1243 | |
1244 | . The ``pass:[{]`` prefix. | |
1245 | ||
27d52a19 | 1246 | . A valid {py3} name which is not `ICITTE`. |
71aaa3f7 PP |
1247 | |
1248 | . The `=` character. | |
1249 | ||
27d52a19 PP |
1250 | . A valid {py3} expression of which the evaluation result type |
1251 | is `int`, `float`, or `bool` (automatically converted to `int`). | |
05f81895 PP |
1252 | + |
1253 | For a variable assignment at some source location{nbsp}__**L**__, this | |
320644e2 PP |
1254 | expression may contain: |
1255 | + | |
1256 | -- | |
1257 | * The name of any <<label,label>> defined before{nbsp}__**L**__ | |
1258 | which isn't within a nested group. | |
1259 | * The name of any <<variable-assignment,variable>> known | |
1260 | at{nbsp}__**L**__. | |
1261 | -- | |
05f81895 | 1262 | + |
269f6eb3 PP |
1263 | The value of the special name `ICITTE` (`int` type) in this expression |
1264 | is the <<cur-offset,current offset>>. | |
71aaa3f7 PP |
1265 | |
1266 | . The `}` suffix. | |
1267 | ||
1268 | ==== | |
1269 | Input: | |
1270 | ||
1271 | ---- | |
1272 | {mix = 101} {le} | |
1273 | {meow = 42} 11 22 {meow:8} 33 {meow = ICITTE + 17} | |
1274 | "yooo" {meow + mix : 16} | |
1275 | ---- | |
1276 | ||
1277 | Output: | |
1278 | ||
1279 | ---- | |
1280 | 11 22 2a 33 79 6f 6f 6f 7a 00 ┆ •"*3yoooz• | |
1281 | ---- | |
1282 | ==== | |
1283 | ||
1284 | === Group | |
1285 | ||
1286 | A _group_ is a scoped sequence of items. | |
1287 | ||
1288 | The <<label,labels>> within a group aren't visible outside of it. | |
1289 | ||
e57a18e1 PP |
1290 | The main purpose of a group is to <<post-item-repetition,repeat>> more |
1291 | than a single item and to isolate labels. | |
71aaa3f7 PP |
1292 | |
1293 | A group is: | |
1294 | ||
261c5ecf | 1295 | . The `(`, `!group`, or `!g` opening. |
71aaa3f7 PP |
1296 | |
1297 | . Zero or more items. | |
1298 | ||
261c5ecf PP |
1299 | . Depending on the group opening: |
1300 | + | |
1301 | -- | |
1302 | `(`:: | |
1303 | The `)` closing. | |
1304 | ||
1305 | `!group`:: | |
1306 | `!g`:: | |
1307 | The `!end` closing. | |
1308 | -- | |
71aaa3f7 PP |
1309 | |
1310 | ==== | |
1311 | Input: | |
1312 | ||
1313 | ---- | |
1314 | ((aa bb cc) dd () ee) "leclerc" | |
1315 | ---- | |
1316 | ||
1317 | Output: | |
1318 | ||
1319 | ---- | |
1320 | aa bb cc dd ee 6c 65 63 6c 65 72 63 ┆ •••••leclerc | |
1321 | ---- | |
1322 | ==== | |
1323 | ||
1324 | ==== | |
1325 | Input: | |
1326 | ||
1327 | ---- | |
261c5ecf PP |
1328 | !group |
1329 | (aa bb cc) * 3 dd ee | |
1330 | !end * 5 | |
71aaa3f7 PP |
1331 | ---- |
1332 | ||
1333 | Output: | |
1334 | ||
1335 | ---- | |
1336 | aa bb cc aa bb cc aa bb cc dd ee aa bb cc aa bb | |
1337 | cc aa bb cc dd ee aa bb cc aa bb cc aa bb cc dd | |
1338 | ee aa bb cc aa bb cc aa bb cc dd ee aa bb cc aa | |
1339 | bb cc aa bb cc dd ee | |
1340 | ---- | |
1341 | ==== | |
1342 | ||
1343 | ==== | |
1344 | Input: | |
1345 | ||
1346 | ---- | |
1347 | {be} | |
1348 | ( | |
1349 | <str_beg> u16le"sébastien diaz" <str_end> | |
1350 | {ICITTE - str_beg : 8} | |
1351 | {(end - str_beg) * 5 : 24} | |
1352 | ) * 3 | |
1353 | <end> | |
1354 | ---- | |
1355 | ||
1356 | Output: | |
1357 | ||
1358 | ---- | |
1359 | 73 00 e9 00 62 00 61 00 73 00 74 00 69 00 65 00 ┆ s•••b•a•s•t•i•e• | |
1360 | 6e 00 20 00 64 00 69 00 61 00 7a 00 1c 00 01 e0 ┆ n• •d•i•a•z••••• | |
1361 | 73 00 e9 00 62 00 61 00 73 00 74 00 69 00 65 00 ┆ s•••b•a•s•t•i•e• | |
1362 | 6e 00 20 00 64 00 69 00 61 00 7a 00 1c 00 01 40 ┆ n• •d•i•a•z••••@ | |
1363 | 73 00 e9 00 62 00 61 00 73 00 74 00 69 00 65 00 ┆ s•••b•a•s•t•i•e• | |
1364 | 6e 00 20 00 64 00 69 00 61 00 7a 00 1c 00 00 a0 ┆ n• •d•i•a•z••••• | |
1365 | ---- | |
1366 | ==== | |
1367 | ||
27d52a19 PP |
1368 | === Conditional block |
1369 | ||
12b5dbc0 PP |
1370 | A _conditional block_ represents either the bytes of zero or more items |
1371 | if some expression is true, or the bytes of zero or more other items if | |
1372 | it's false. | |
27d52a19 PP |
1373 | |
1374 | A conditional block is: | |
1375 | ||
261c5ecf | 1376 | . The `!if` opening. |
27d52a19 PP |
1377 | |
1378 | . One of: | |
1379 | ||
1380 | ** The ``pass:[{]`` prefix, a valid {py3} expression of which the | |
1381 | evaluation result type is `int` or `bool` (automatically converted to | |
1382 | `int`), and the ``pass:[}]`` suffix. | |
1383 | + | |
320644e2 PP |
1384 | For a conditional block at some source location{nbsp}__**L**__, this |
1385 | expression may contain: | |
27d52a19 PP |
1386 | + |
1387 | -- | |
1388 | * The name of any <<label,label>> defined before{nbsp}__**L**__ | |
1389 | which isn't within a nested group. | |
1390 | * The name of any <<variable-assignment,variable>> known | |
320644e2 | 1391 | at{nbsp}__**L**__. |
27d52a19 PP |
1392 | -- |
1393 | + | |
1394 | The value of the special name `ICITTE` (`int` type) in this expression | |
1395 | is the <<cur-offset,current offset>> (before handling the contained | |
1396 | items). | |
1397 | ||
1398 | ** A valid {py3} name. | |
1399 | + | |
1400 | For the name `__NAME__`, this is equivalent to the | |
1401 | `pass:[{]__NAME__pass:[}]` form above. | |
1402 | ||
12b5dbc0 PP |
1403 | . Zero or more items to be handled when the condition is true. |
1404 | ||
1405 | . **Optional**: | |
1406 | ||
1407 | .. The `!else` opening. | |
1408 | .. Zero or more items to be handled when the condition is false. | |
27d52a19 | 1409 | |
261c5ecf | 1410 | . The `!end` closing. |
27d52a19 PP |
1411 | |
1412 | ==== | |
1413 | Input: | |
1414 | ||
1415 | ---- | |
1416 | {at = 1} | |
1417 | {rep_count = 9} | |
1418 | ||
1419 | !repeat rep_count | |
1420 | "meow " | |
1421 | ||
1422 | !if {ICITTE > 25} | |
1423 | "mix" | |
12b5dbc0 PP |
1424 | !else |
1425 | "zoom" | |
27d52a19 PP |
1426 | !end |
1427 | ||
12b5dbc0 PP |
1428 | !if {at < rep_count} 20 !end |
1429 | ||
27d52a19 PP |
1430 | {at = at + 1} |
1431 | !end | |
1432 | ---- | |
1433 | ||
1434 | Output: | |
1435 | ||
1436 | ---- | |
12b5dbc0 PP |
1437 | 6d 65 6f 77 20 7a 6f 6f 6d 20 6d 65 6f 77 20 7a ┆ meow zoom meow z |
1438 | 6f 6f 6d 20 6d 65 6f 77 20 7a 6f 6f 6d 20 6d 65 ┆ oom meow zoom me | |
1439 | 6f 77 20 6d 69 78 20 6d 65 6f 77 20 6d 69 78 20 ┆ ow mix meow mix | |
1440 | 6d 65 6f 77 20 6d 69 78 20 6d 65 6f 77 20 6d 69 ┆ meow mix meow mi | |
27d52a19 | 1441 | 78 20 6d 65 6f 77 20 6d 69 78 20 6d 65 6f 77 20 ┆ x meow mix meow |
12b5dbc0 | 1442 | 6d 69 78 ┆ mix |
27d52a19 PP |
1443 | ---- |
1444 | ==== | |
1445 | ||
1446 | ==== | |
1447 | Input: | |
1448 | ||
1449 | ---- | |
1450 | <str_beg> | |
1451 | u16le"meow mix!" | |
1452 | <str_end> | |
1453 | ||
1454 | !if {str_end - str_beg > 10} | |
1455 | " BIG" | |
1456 | !end | |
1457 | ---- | |
1458 | ||
1459 | Output: | |
1460 | ||
1461 | ---- | |
1462 | 6d 00 65 00 6f 00 77 00 20 00 6d 00 69 00 78 00 ┆ m•e•o•w• •m•i•x• | |
1463 | 21 00 20 42 49 47 ┆ !• BIG | |
1464 | ---- | |
1465 | ==== | |
1466 | ||
e57a18e1 | 1467 | === Repetition block |
71aaa3f7 | 1468 | |
e57a18e1 PP |
1469 | A _repetition block_ represents the bytes of one or more items repeated |
1470 | a given number of times. | |
676f6189 | 1471 | |
e57a18e1 | 1472 | A repetition block is: |
71aaa3f7 | 1473 | |
261c5ecf | 1474 | . The `!repeat` or `!r` opening. |
71aaa3f7 | 1475 | |
2adf4336 PP |
1476 | . One of: |
1477 | ||
fc21bb27 PP |
1478 | ** A <<const-int,positive constant integer>> which is the number of |
1479 | times to repeat the previous item. | |
2adf4336 | 1480 | |
27d52a19 PP |
1481 | ** The ``pass:[{]`` prefix, a valid {py3} expression of which the |
1482 | evaluation result type is `int` or `bool` (automatically converted to | |
1483 | `int`), and the ``pass:[}]`` suffix. | |
05f81895 | 1484 | + |
320644e2 PP |
1485 | For a repetition block at some source location{nbsp}__**L**__, this |
1486 | expression may contain: | |
05f81895 PP |
1487 | + |
1488 | -- | |
27d52a19 PP |
1489 | * The name of any <<label,label>> defined before{nbsp}__**L**__ |
1490 | which isn't within a nested group. | |
05f81895 | 1491 | * The name of any <<variable-assignment,variable>> known |
320644e2 | 1492 | at{nbsp}__**L**__. |
05f81895 PP |
1493 | -- |
1494 | + | |
e57a18e1 PP |
1495 | The value of the special name `ICITTE` (`int` type) in this expression |
1496 | is the <<cur-offset,current offset>> (before handling the items to | |
1497 | repeat). | |
1498 | ||
1499 | ** A valid {py3} name. | |
1500 | + | |
1501 | For the name `__NAME__`, this is equivalent to the | |
1502 | `pass:[{]__NAME__pass:[}]` form above. | |
1503 | ||
1504 | . Zero or more items. | |
1505 | ||
261c5ecf | 1506 | . The `!end` closing. |
e57a18e1 PP |
1507 | |
1508 | You may also use a <<post-item-repetition,post-item repetition>> after | |
1509 | some items. The form ``!repeat{nbsp}__X__{nbsp}__ITEMS__{nbsp}!end`` | |
1510 | is equivalent to ``(__ITEMS__){nbsp}pass:[*]{nbsp}__X__``. | |
71aaa3f7 PP |
1511 | |
1512 | ==== | |
1513 | Input: | |
1514 | ||
1515 | ---- | |
fc21bb27 | 1516 | !repeat 0o400 |
e57a18e1 PP |
1517 | {end - ICITTE - 1 : 8} |
1518 | !end | |
1519 | ||
1520 | <end> | |
71aaa3f7 PP |
1521 | ---- |
1522 | ||
1523 | Output: | |
1524 | ||
1525 | ---- | |
1526 | ff fe fd fc fb fa f9 f8 f7 f6 f5 f4 f3 f2 f1 f0 ┆ •••••••••••••••• | |
1527 | ef ee ed ec eb ea e9 e8 e7 e6 e5 e4 e3 e2 e1 e0 ┆ •••••••••••••••• | |
1528 | df de dd dc db da d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 ┆ •••••••••••••••• | |
1529 | cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0 ┆ •••••••••••••••• | |
1530 | bf be bd bc bb ba b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 ┆ •••••••••••••••• | |
1531 | af ae ad ac ab aa a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 ┆ •••••••••••••••• | |
1532 | 9f 9e 9d 9c 9b 9a 99 98 97 96 95 94 93 92 91 90 ┆ •••••••••••••••• | |
1533 | 8f 8e 8d 8c 8b 8a 89 88 87 86 85 84 83 82 81 80 ┆ •••••••••••••••• | |
1534 | 7f 7e 7d 7c 7b 7a 79 78 77 76 75 74 73 72 71 70 ┆ •~}|{zyxwvutsrqp | |
1535 | 6f 6e 6d 6c 6b 6a 69 68 67 66 65 64 63 62 61 60 ┆ onmlkjihgfedcba` | |
1536 | 5f 5e 5d 5c 5b 5a 59 58 57 56 55 54 53 52 51 50 ┆ _^]\[ZYXWVUTSRQP | |
1537 | 4f 4e 4d 4c 4b 4a 49 48 47 46 45 44 43 42 41 40 ┆ ONMLKJIHGFEDCBA@ | |
1538 | 3f 3e 3d 3c 3b 3a 39 38 37 36 35 34 33 32 31 30 ┆ ?>=<;:9876543210 | |
1539 | 2f 2e 2d 2c 2b 2a 29 28 27 26 25 24 23 22 21 20 ┆ /.-,+*)('&%$#"! | |
1540 | 1f 1e 1d 1c 1b 1a 19 18 17 16 15 14 13 12 11 10 ┆ •••••••••••••••• | |
1541 | 0f 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00 ┆ •••••••••••••••• | |
1542 | ---- | |
1543 | ==== | |
1544 | ||
2adf4336 PP |
1545 | ==== |
1546 | Input: | |
1547 | ||
1548 | ---- | |
1549 | {times = 1} | |
e57a18e1 | 1550 | |
2adf4336 | 1551 | aa bb cc dd |
e57a18e1 PP |
1552 | |
1553 | !repeat 3 | |
2adf4336 | 1554 | <here> |
e57a18e1 PP |
1555 | |
1556 | !repeat {here + 1} | |
1557 | ee ff | |
1558 | !end | |
1559 | ||
1560 | 11 22 !repeat times 33 !end | |
1561 | ||
2adf4336 | 1562 | {times = times + 1} |
e57a18e1 PP |
1563 | !end |
1564 | ||
2adf4336 PP |
1565 | "coucou!" |
1566 | ---- | |
1567 | ||
1568 | Output: | |
1569 | ||
1570 | ---- | |
1571 | aa bb cc dd ee ff ee ff ee ff ee ff ee ff 11 22 ┆ •••••••••••••••" | |
1572 | 33 ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ 3••••••••••••••• | |
1573 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1574 | ff ee ff ee ff 11 22 33 33 ee ff ee ff ee ff ee ┆ ••••••"33••••••• | |
1575 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1576 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1577 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1578 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1579 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1580 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1581 | ff ee ff ee ff ee ff ee ff ee ff ee ff 11 22 33 ┆ ••••••••••••••"3 | |
1582 | 33 33 63 6f 75 63 6f 75 21 ┆ 33coucou! | |
1583 | ---- | |
1584 | ==== | |
1585 | ||
320644e2 PP |
1586 | === Macro definition block |
1587 | ||
1588 | A _macro definition block_ associates a name and parameter names to | |
1589 | a group of items. | |
1590 | ||
1591 | A macro definition block doesn't lead to generated bytes itself: a | |
1592 | <<macro-expansion,macro expansion>> does so. | |
1593 | ||
1594 | A macro definition may only exist at the root level, that is, not within | |
1595 | a <<group,group>>, a <<repetition-block,repetition block>>, a | |
1596 | <<conditional-block,conditional block>>, or another | |
1597 | <<macro-definition-block,macro definition block>>. | |
1598 | ||
1599 | All macro definitions must have unique names. | |
1600 | ||
1601 | A macro definition is: | |
1602 | ||
1603 | . The `!macro` or `!m` opening. | |
1604 | ||
1605 | . A valid {py3} name (the macro name). | |
1606 | ||
1607 | . The `(` parameter name list prefix. | |
1608 | ||
1609 | . A comma-separated list of zero or more unique parameter names, | |
1610 | each one being a valid {py3} name. | |
1611 | ||
1612 | . The `)` parameter name list suffix. | |
1613 | ||
1614 | . Zero or more items except, recursively, a macro definition block. | |
1615 | ||
1616 | . The `!end` closing. | |
1617 | ||
1618 | ==== | |
1619 | ---- | |
1620 | !macro bake() | |
1621 | {le} {ICITTE * 8 : 16} | |
1622 | u16le"predict explode" | |
1623 | !end | |
1624 | ---- | |
1625 | ==== | |
1626 | ||
1627 | ==== | |
1628 | ---- | |
1629 | !macro nail(rep, with_extra, val) | |
1630 | {iter = 1} | |
1631 | ||
1632 | !repeat rep | |
1633 | {val + iter : uleb128} | |
1634 | {0xdeadbeef : 32} | |
1635 | {iter = iter + 1} | |
1636 | !end | |
1637 | ||
1638 | !if with_extra | |
1639 | "meow mix\0" | |
1640 | !end | |
1641 | !end | |
1642 | ---- | |
1643 | ==== | |
1644 | ||
1645 | === Macro expansion | |
1646 | ||
1647 | A _macro expansion_ expands the items of a defined | |
1648 | <<macro-definition-block,macro>>. | |
1649 | ||
1650 | The macro to expand must be defined _before_ the expansion. | |
1651 | ||
1652 | The <<state,state>> before handling the first item of the chosen macro | |
1653 | is: | |
1654 | ||
1655 | <<cur-offset,Current offset>>:: | |
1656 | Unchanged. | |
1657 | ||
1658 | <<cur-bo,Current byte order>>:: | |
1659 | Unchanged. | |
1660 | ||
1661 | Variables:: | |
1662 | The only available variables initially are the macro parameters. | |
1663 | ||
1664 | Labels:: | |
1665 | None. | |
1666 | ||
1667 | The state after having handled the last item of the chosen macro is: | |
1668 | ||
1669 | Current offset:: | |
1670 | The one before handling the first item of the macro plus the size | |
1671 | of the generated data of the macro expansion. | |
1672 | + | |
1673 | IMPORTANT: This means <<current-offset-setting,current offset setting>> | |
1674 | items within the expanded macro don't impact the final current offset. | |
1675 | ||
1676 | Current byte order:: | |
1677 | The one before handling the first item of the macro. | |
1678 | ||
1679 | Variables:: | |
1680 | The ones before handling the first item of the macro. | |
1681 | ||
1682 | Labels:: | |
1683 | The ones before handling the first item of the macro. | |
1684 | ||
1685 | A macro expansion is: | |
1686 | ||
1687 | . The `m:` prefix. | |
1688 | ||
1689 | . A valid {py3} name (the name of the macro to expand). | |
1690 | ||
1691 | . The `(` parameter value list prefix. | |
1692 | ||
1693 | . A comma-separated list of zero or more unique parameter values. | |
1694 | + | |
1695 | The number of parameter values must match the number of parameter | |
1696 | names of the definition of the chosen macro. | |
1697 | + | |
1698 | A parameter value is one of: | |
1699 | + | |
1700 | -- | |
fc21bb27 | 1701 | * A <<const-int,constant integer>>, possibly negative. |
320644e2 PP |
1702 | |
1703 | * The ``pass:[{]`` prefix, a valid {py3} expression of which the | |
1704 | evaluation result type is `int` or `bool` (automatically converted to | |
1705 | `int`), and the ``pass:[}]`` suffix. | |
1706 | + | |
1707 | For a macro expansion at some source location{nbsp}__**L**__, this | |
1708 | expression may contain: | |
1709 | ||
1710 | ** The name of any <<label,label>> defined before{nbsp}__**L**__ | |
1711 | which isn't within a nested group. | |
1712 | ** The name of any <<variable-assignment,variable>> known | |
1713 | at{nbsp}__**L**__. | |
1714 | ||
1715 | + | |
1716 | The value of the special name `ICITTE` (`int` type) in this expression | |
1717 | is the <<cur-offset,current offset>> (before handling the items of the | |
1718 | chosen macro). | |
1719 | ||
1720 | * A valid {py3} name. | |
1721 | + | |
1722 | For the name `__NAME__`, this is equivalent to the | |
1723 | `pass:[{]__NAME__pass:[}]` form above. | |
1724 | -- | |
1725 | ||
1726 | . The `)` parameter value list suffix. | |
1727 | ||
1728 | ==== | |
1729 | Input: | |
1730 | ||
1731 | ---- | |
1732 | !macro bake() | |
1733 | {le} {ICITTE * 8 : 16} | |
1734 | u16le"predict explode" | |
1735 | !end | |
1736 | ||
1737 | "hello [" m:bake() "] world" | |
1738 | ||
1739 | m:bake() * 5 | |
1740 | ---- | |
1741 | ||
1742 | Output: | |
1743 | ||
1744 | ---- | |
1745 | 68 65 6c 6c 6f 20 5b 38 00 70 00 72 00 65 00 64 ┆ hello [8•p•r•e•d | |
1746 | 00 69 00 63 00 74 00 20 00 65 00 78 00 70 00 6c ┆ •i•c•t• •e•x•p•l | |
1747 | 00 6f 00 64 00 65 00 5d 20 77 6f 72 6c 64 70 01 ┆ •o•d•e•] worldp• | |
1748 | 70 00 72 00 65 00 64 00 69 00 63 00 74 00 20 00 ┆ p•r•e•d•i•c•t• • | |
1749 | 65 00 78 00 70 00 6c 00 6f 00 64 00 65 00 70 02 ┆ e•x•p•l•o•d•e•p• | |
1750 | 70 00 72 00 65 00 64 00 69 00 63 00 74 00 20 00 ┆ p•r•e•d•i•c•t• • | |
1751 | 65 00 78 00 70 00 6c 00 6f 00 64 00 65 00 70 03 ┆ e•x•p•l•o•d•e•p• | |
1752 | 70 00 72 00 65 00 64 00 69 00 63 00 74 00 20 00 ┆ p•r•e•d•i•c•t• • | |
1753 | 65 00 78 00 70 00 6c 00 6f 00 64 00 65 00 70 04 ┆ e•x•p•l•o•d•e•p• | |
1754 | 70 00 72 00 65 00 64 00 69 00 63 00 74 00 20 00 ┆ p•r•e•d•i•c•t• • | |
1755 | 65 00 78 00 70 00 6c 00 6f 00 64 00 65 00 70 05 ┆ e•x•p•l•o•d•e•p• | |
1756 | 70 00 72 00 65 00 64 00 69 00 63 00 74 00 20 00 ┆ p•r•e•d•i•c•t• • | |
1757 | 65 00 78 00 70 00 6c 00 6f 00 64 00 65 00 ┆ e•x•p•l•o•d•e• | |
1758 | ---- | |
1759 | ==== | |
1760 | ||
1761 | ==== | |
1762 | Input: | |
1763 | ||
1764 | ---- | |
1765 | !macro A(val, is_be) | |
1766 | {le} | |
1767 | ||
1768 | !if is_be | |
1769 | {be} | |
1770 | !end | |
1771 | ||
1772 | {val : 16} | |
1773 | !end | |
1774 | ||
1775 | !macro B(rep, is_be) | |
1776 | {iter = 1} | |
1777 | ||
1778 | !repeat rep | |
1779 | m:A({iter * 3}, is_be) | |
1780 | {iter = iter + 1} | |
1781 | !end | |
1782 | !end | |
1783 | ||
1784 | m:B(5, 1) | |
1785 | m:B(3, 0) | |
1786 | ---- | |
1787 | ||
1788 | Output: | |
1789 | ||
1790 | ---- | |
1791 | 00 03 00 06 00 09 00 0c 00 0f 03 00 06 00 09 00 | |
1792 | ---- | |
1793 | ==== | |
1794 | ||
e57a18e1 PP |
1795 | === Post-item repetition |
1796 | ||
1797 | A _post-item repetition_ represents the bytes of an item repeated a | |
1798 | given number of times. | |
1799 | ||
1800 | A post-item repetition is: | |
1801 | ||
27d52a19 | 1802 | . One of those items: |
e57a18e1 | 1803 | |
27d52a19 PP |
1804 | ** A <<byte-constant,byte constant>>. |
1805 | ** A <<literal-string,literal string>>. | |
1806 | ** A <<fixed-length-number,fixed-length number>>. | |
1807 | ** An <<leb128-integer,LEB128 integer>>. | |
320644e2 | 1808 | ** A <<macro-expansion,macro-expansion>>. |
27d52a19 | 1809 | ** A <<group,group>>. |
e57a18e1 PP |
1810 | |
1811 | . The ``pass:[*]`` character. | |
1812 | ||
1813 | . One of: | |
1814 | ||
1815 | ** A positive integer (hexadecimal starting with `0x` or `0X` accepted) | |
1816 | which is the number of times to repeat the previous item. | |
1817 | ||
27d52a19 PP |
1818 | ** The ``pass:[{]`` prefix, a valid {py3} expression of which the |
1819 | evaluation result type is `int` or `bool` (automatically converted to | |
1820 | `int`), and the ``pass:[}]`` suffix. | |
e57a18e1 | 1821 | + |
320644e2 PP |
1822 | For a post-item repetition at some source location{nbsp}__**L**__, this |
1823 | expression may contain: | |
e57a18e1 PP |
1824 | + |
1825 | -- | |
27d52a19 PP |
1826 | * The name of any <<label,label>> defined before{nbsp}__**L**__ |
1827 | which isn't within a nested group and | |
1828 | which isn't part of the repeated item. | |
e57a18e1 PP |
1829 | * The name of any <<variable-assignment,variable>> known |
1830 | at{nbsp}__**L**__, which isn't part of its repeated item, and which | |
320644e2 | 1831 | doesn't. |
e57a18e1 PP |
1832 | -- |
1833 | + | |
1834 | The value of the special name `ICITTE` (`int` type) in this expression | |
1835 | is the <<cur-offset,current offset>> (before handling the items to | |
1836 | repeat). | |
1837 | ||
1838 | ** A valid {py3} name. | |
1839 | + | |
1840 | For the name `__NAME__`, this is equivalent to the | |
1841 | `pass:[{]__NAME__pass:[}]` form above. | |
1842 | ||
1843 | You may also use a <<repetition-block,repetition block>>. The form | |
1844 | ``__ITEM__{nbsp}pass:[*]{nbsp}__X__`` is equivalent to | |
1845 | ``!repeat{nbsp}__X__{nbsp}__ITEM__{nbsp}!end``. | |
1846 | ||
1847 | ==== | |
1848 | Input: | |
1849 | ||
1850 | ---- | |
1851 | {end - ICITTE - 1 : 8} * 0x100 <end> | |
1852 | ---- | |
1853 | ||
1854 | Output: | |
1855 | ||
1856 | ---- | |
1857 | ff fe fd fc fb fa f9 f8 f7 f6 f5 f4 f3 f2 f1 f0 ┆ •••••••••••••••• | |
1858 | ef ee ed ec eb ea e9 e8 e7 e6 e5 e4 e3 e2 e1 e0 ┆ •••••••••••••••• | |
1859 | df de dd dc db da d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 ┆ •••••••••••••••• | |
1860 | cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0 ┆ •••••••••••••••• | |
1861 | bf be bd bc bb ba b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 ┆ •••••••••••••••• | |
1862 | af ae ad ac ab aa a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 ┆ •••••••••••••••• | |
1863 | 9f 9e 9d 9c 9b 9a 99 98 97 96 95 94 93 92 91 90 ┆ •••••••••••••••• | |
1864 | 8f 8e 8d 8c 8b 8a 89 88 87 86 85 84 83 82 81 80 ┆ •••••••••••••••• | |
1865 | 7f 7e 7d 7c 7b 7a 79 78 77 76 75 74 73 72 71 70 ┆ •~}|{zyxwvutsrqp | |
1866 | 6f 6e 6d 6c 6b 6a 69 68 67 66 65 64 63 62 61 60 ┆ onmlkjihgfedcba` | |
1867 | 5f 5e 5d 5c 5b 5a 59 58 57 56 55 54 53 52 51 50 ┆ _^]\[ZYXWVUTSRQP | |
1868 | 4f 4e 4d 4c 4b 4a 49 48 47 46 45 44 43 42 41 40 ┆ ONMLKJIHGFEDCBA@ | |
1869 | 3f 3e 3d 3c 3b 3a 39 38 37 36 35 34 33 32 31 30 ┆ ?>=<;:9876543210 | |
1870 | 2f 2e 2d 2c 2b 2a 29 28 27 26 25 24 23 22 21 20 ┆ /.-,+*)('&%$#"! | |
1871 | 1f 1e 1d 1c 1b 1a 19 18 17 16 15 14 13 12 11 10 ┆ •••••••••••••••• | |
1872 | 0f 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00 ┆ •••••••••••••••• | |
1873 | ---- | |
1874 | ==== | |
1875 | ||
1876 | ==== | |
1877 | Input: | |
1878 | ||
1879 | ---- | |
1880 | {times = 1} | |
1881 | aa bb cc dd | |
1882 | ( | |
1883 | <here> | |
1884 | (ee ff) * {here + 1} | |
1885 | 11 22 33 * {times} | |
1886 | {times = times + 1} | |
1887 | ) * 3 | |
1888 | "coucou!" | |
1889 | ---- | |
1890 | ||
1891 | Output: | |
1892 | ||
1893 | ---- | |
1894 | aa bb cc dd ee ff ee ff ee ff ee ff ee ff 11 22 ┆ •••••••••••••••" | |
1895 | 33 ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ 3••••••••••••••• | |
1896 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1897 | ff ee ff ee ff 11 22 33 33 ee ff ee ff ee ff ee ┆ ••••••"33••••••• | |
1898 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1899 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1900 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1901 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1902 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1903 | ff ee ff ee ff ee ff ee ff ee ff ee ff ee ff ee ┆ •••••••••••••••• | |
1904 | ff ee ff ee ff ee ff ee ff ee ff ee ff 11 22 33 ┆ ••••••••••••••"3 | |
1905 | 33 33 63 6f 75 63 6f 75 21 ┆ 33coucou! | |
1906 | ---- | |
1907 | ==== | |
1908 | ||
71aaa3f7 PP |
1909 | == Command-line tool |
1910 | ||
1911 | If you <<install-normand,installed>> the `normand` package, then you | |
1912 | can use the `normand` command-line tool: | |
1913 | ||
1914 | ---- | |
1915 | $ normand <<< '"ma gang de malades"' | hexdump -C | |
1916 | ---- | |
1917 | ||
1918 | ---- | |
1919 | 00000000 6d 61 20 67 61 6e 67 20 64 65 20 6d 61 6c 61 64 |ma gang de malad| | |
1920 | 00000010 65 73 |es| | |
1921 | ---- | |
1922 | ||
1923 | If you copy the `normand.py` module to your own project, then you can | |
1924 | run the module itself: | |
1925 | ||
1926 | ---- | |
1927 | $ python3 -m normand <<< '"ma gang de malades"' | hexdump -C | |
1928 | ---- | |
1929 | ||
1930 | ---- | |
1931 | 00000000 6d 61 20 67 61 6e 67 20 64 65 20 6d 61 6c 61 64 |ma gang de malad| | |
1932 | 00000010 65 73 |es| | |
1933 | ---- | |
1934 | ||
1935 | Without a path argument, the `normand` tool reads from the standard | |
1936 | input. | |
1937 | ||
1938 | The `normand` tool prints the generated binary data to the standard | |
1939 | output. | |
1940 | ||
1941 | Various options control the initial <<state,state>> of the processor: | |
1942 | use the `--help` option to learn more. | |
1943 | ||
1944 | == {py3} API | |
1945 | ||
e57a18e1 | 1946 | The whole `normand` package/module public API is: |
71aaa3f7 PP |
1947 | |
1948 | [source,python] | |
1949 | ---- | |
e57a18e1 | 1950 | # Byte order. |
71aaa3f7 PP |
1951 | class ByteOrder(enum.Enum): |
1952 | # Big endian. | |
1953 | BE = ... | |
1954 | ||
1955 | # Little endian. | |
1956 | LE = ... | |
1957 | ||
1958 | ||
e57a18e1 PP |
1959 | # Text location. |
1960 | class TextLocation: | |
71aaa3f7 PP |
1961 | # Line number. |
1962 | @property | |
1963 | def line_no(self) -> int: | |
1964 | ... | |
1965 | ||
1966 | # Column number. | |
1967 | @property | |
1968 | def col_no(self) -> int: | |
1969 | ... | |
1970 | ||
1971 | ||
f5dcb24c PP |
1972 | # Parsing error message. |
1973 | class ParseErrorMessage: | |
1974 | # Message text. | |
1975 | @property | |
1976 | def text(self): | |
1977 | ... | |
1978 | ||
1979 | # Source text location. | |
1980 | @property | |
1981 | def text_location(self): | |
1982 | ... | |
1983 | ||
1984 | ||
e57a18e1 | 1985 | # Parsing error. |
71aaa3f7 | 1986 | class ParseError(RuntimeError): |
f5dcb24c PP |
1987 | # Parsing error messages. |
1988 | # | |
1989 | # The first message is the most _specific_ one. | |
71aaa3f7 | 1990 | @property |
f5dcb24c | 1991 | def messages(self): |
71aaa3f7 PP |
1992 | ... |
1993 | ||
1994 | ||
e57a18e1 PP |
1995 | # Variables dictionary type (for type hints). |
1996 | VariablesT = typing.Dict[str, typing.Union[int, float]] | |
1997 | ||
1998 | ||
1999 | # Labels dictionary type (for type hints). | |
2000 | LabelsT = typing.Dict[str, int] | |
1b8aa84a PP |
2001 | |
2002 | ||
e57a18e1 | 2003 | # Parsing result. |
71aaa3f7 PP |
2004 | class ParseResult: |
2005 | # Generated data. | |
2006 | @property | |
2007 | def data(self) -> bytearray: | |
2008 | ... | |
2009 | ||
2010 | # Updated variable values. | |
2011 | @property | |
1b8aa84a | 2012 | def variables(self) -> SymbolsT: |
71aaa3f7 PP |
2013 | ... |
2014 | ||
2015 | # Updated main group label values. | |
2016 | @property | |
1b8aa84a | 2017 | def labels(self) -> SymbolsT: |
71aaa3f7 PP |
2018 | ... |
2019 | ||
2020 | # Final offset. | |
2021 | @property | |
2022 | def offset(self) -> int: | |
2023 | ... | |
2024 | ||
2025 | # Final byte order. | |
2026 | @property | |
1b8aa84a | 2027 | def byte_order(self) -> typing.Optional[ByteOrder]: |
71aaa3f7 PP |
2028 | ... |
2029 | ||
1b8aa84a | 2030 | |
e57a18e1 PP |
2031 | # Parses the `normand` input using the initial state defined by |
2032 | # `init_variables`, `init_labels`, `init_offset`, and `init_byte_order`, | |
2033 | # and returns the corresponding parsing result. | |
71aaa3f7 | 2034 | def parse(normand: str, |
1b8aa84a PP |
2035 | init_variables: typing.Optional[SymbolsT] = None, |
2036 | init_labels: typing.Optional[SymbolsT] = None, | |
71aaa3f7 PP |
2037 | init_offset: int = 0, |
2038 | init_byte_order: typing.Optional[ByteOrder] = None) -> ParseResult: | |
2039 | ... | |
2040 | ---- | |
2041 | ||
2042 | The `normand` parameter is the actual <<learn-normand,Normand input>> | |
2043 | while the other parameters control the initial <<state,state>>. | |
2044 | ||
2045 | The `parse()` function raises a `ParseError` instance should it fail to | |
2046 | parse the `normand` string for any reason. | |
bf8f3b38 PP |
2047 | |
2048 | == Development | |
2049 | ||
2050 | Normand is a https://python-poetry.org/[Poetry] project. | |
2051 | ||
2052 | To develop it, install it through Poetry and enter the virtual | |
2053 | environment: | |
2054 | ||
2055 | ---- | |
2056 | $ poetry install | |
2057 | $ poetry shell | |
2058 | $ normand <<< '"lol" * 10 0a' | |
2059 | ---- | |
2060 | ||
2061 | `normand.py` is processed by: | |
2062 | ||
2063 | * https://microsoft.github.io/pyright/[Pyright] | |
2064 | * https://github.com/psf/black[Black] | |
2065 | * https://pycqa.github.io/isort/[isort] | |
2066 | ||
2067 | === Testing | |
2068 | ||
2069 | Use https://docs.pytest.org/[pytest] to test Normand once the package is | |
2070 | part of your virtual environment, for example: | |
2071 | ||
2072 | ---- | |
2073 | $ poetry install | |
2074 | $ poetry run pip3 install pytest | |
2075 | $ poetry run pytest | |
2076 | ---- | |
2077 | ||
2078 | The `pytest` project is currently not a development dependency in | |
2079 | `pyproject.toml` due to backward compatibiliy issues with | |
2080 | Python{nbsp}3.4. | |
2081 | ||
2082 | In the `tests` directory, each `*.nt` file is a test. The file name | |
2083 | prefix indicates what it's meant to test: | |
2084 | ||
2085 | `pass-`:: | |
2086 | Everything above the `---` line is the valid Normand input | |
2087 | to test. | |
2088 | + | |
2089 | Everything below the `---` line is the expected data | |
2090 | (whitespace-separated hexadecimal bytes). | |
2091 | ||
2092 | `fail-`:: | |
2093 | Everything above the `---` line is the invalid Normand input | |
2094 | to test. | |
2095 | + | |
2096 | Everything below the `---` line is the expected error message having | |
2097 | this form: | |
2098 | + | |
2099 | ---- | |
2100 | LINE:COL - MESSAGE | |
2101 | ---- | |
2102 | ||
2103 | === Contributing | |
2104 | ||
2105 | Normand uses https://review.lttng.org/admin/repos/normand,general[Gerrit] | |
2106 | for code review. | |
2107 | ||
2108 | To report a bug, https://github.com/efficios/normand/issues/new[create a | |
2109 | GitHub issue]. |