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4dfca05b | 1 | Common Trace Format (CTF) Specification (pre-v1.8) |
5ba9f198 MD |
2 | |
3 | Mathieu Desnoyers, EfficiOS Inc. | |
4 | ||
339a7dde | 5 | The goal of the present document is to specify a trace format that suits the |
cc089c3a | 6 | needs of the embedded, telecom, high-performance and kernel communities. It is |
5ba9f198 | 7 | based on the Common Trace Format Requirements (v1.4) document. It is designed to |
cc089c3a | 8 | allow traces to be natively generated by the Linux kernel, Linux user-space |
6c7226e9 MD |
9 | applications written in C/C++, and hardware components. One major element of |
10 | CTF is the Trace Stream Description Language (TSDL) which flexibility | |
11 | enables description of various binary trace stream layouts. | |
cc089c3a MD |
12 | |
13 | The latest version of this document can be found at: | |
14 | ||
15 | git tree: git://git.efficios.com/ctf.git | |
16 | gitweb: http://git.efficios.com/?p=ctf.git | |
5ba9f198 MD |
17 | |
18 | A reference implementation of a library to read and write this trace format is | |
19 | being implemented within the BabelTrace project, a converter between trace | |
20 | formats. The development tree is available at: | |
21 | ||
22 | git tree: git://git.efficios.com/babeltrace.git | |
23 | gitweb: http://git.efficios.com/?p=babeltrace.git | |
24 | ||
339a7dde MD |
25 | The CE Workgroup of the Linux Foundation, Ericsson, and EfficiOS have |
26 | sponsored this work. | |
27 | ||
5ba9f198 | 28 | |
beabf088 MD |
29 | Table of Contents |
30 | ||
31 | 1. Preliminary definitions | |
32 | 2. High-level representation of a trace | |
33 | 3. Event stream | |
34 | 4. Types | |
35 | 4.1 Basic types | |
36 | 4.1.1 Type inheritance | |
37 | 4.1.2 Alignment | |
38 | 4.1.3 Byte order | |
39 | 4.1.4 Size | |
40 | 4.1.5 Integers | |
41 | 4.1.6 GNU/C bitfields | |
42 | 4.1.7 Floating point | |
43 | 4.1.8 Enumerations | |
44 | 4.2 Compound types | |
45 | 4.2.1 Structures | |
46 | 4.2.2 Variants (Discriminated/Tagged Unions) | |
47 | 4.2.3 Arrays | |
48 | 4.2.4 Sequences | |
49 | 4.2.5 Strings | |
50 | 5. Event Packet Header | |
51 | 5.1 Event Packet Header Description | |
52 | 5.2 Event Packet Context Description | |
53 | 6. Event Structure | |
54 | 6.1 Event Header | |
55 | 6.1.1 Type 1 - Few event IDs | |
56 | 6.1.2 Type 2 - Many event IDs | |
57 | 6.2 Event Context | |
58 | 6.3 Event Payload | |
59 | 6.3.1 Padding | |
60 | 6.3.2 Alignment | |
61 | 7. Trace Stream Description Language (TSDL) | |
62 | 7.1 Meta-data | |
63 | 7.2 Declaration vs Definition | |
64 | 7.3 TSDL Scopes | |
65 | 7.3.1 Lexical Scope | |
37ab95c3 | 66 | 7.3.2 Static and Dynamic Scopes |
beabf088 | 67 | 7.4 TSDL Examples |
2fa70eba | 68 | 8. Clocks |
beabf088 MD |
69 | |
70 | ||
5ba9f198 MD |
71 | 1. Preliminary definitions |
72 | ||
3bf79539 MD |
73 | - Event Trace: An ordered sequence of events. |
74 | - Event Stream: An ordered sequence of events, containing a subset of the | |
75 | trace event types. | |
76 | - Event Packet: A sequence of physically contiguous events within an event | |
77 | stream. | |
5ba9f198 MD |
78 | - Event: This is the basic entry in a trace. (aka: a trace record). |
79 | - An event identifier (ID) relates to the class (a type) of event within | |
3bf79539 MD |
80 | an event stream. |
81 | e.g. event: irq_entry. | |
5ba9f198 MD |
82 | - An event (or event record) relates to a specific instance of an event |
83 | class. | |
3bf79539 MD |
84 | e.g. event: irq_entry, at time X, on CPU Y |
85 | - Source Architecture: Architecture writing the trace. | |
86 | - Reader Architecture: Architecture reading the trace. | |
5ba9f198 MD |
87 | |
88 | ||
89 | 2. High-level representation of a trace | |
90 | ||
3bf79539 MD |
91 | A trace is divided into multiple event streams. Each event stream contains a |
92 | subset of the trace event types. | |
5ba9f198 | 93 | |
3bf79539 MD |
94 | The final output of the trace, after its generation and optional transport over |
95 | the network, is expected to be either on permanent or temporary storage in a | |
96 | virtual file system. Because each event stream is appended to while a trace is | |
32254806 MD |
97 | being recorded, each is associated with a distinct set of files for |
98 | output. Therefore, a stored trace can be represented as a directory | |
99 | containing zero, one or more files per stream. | |
5ba9f198 | 100 | |
6672e9e1 MD |
101 | Meta-data description associated with the trace contains information on |
102 | trace event types expressed in the Trace Stream Description Language | |
103 | (TSDL). This language describes: | |
5ba9f198 MD |
104 | |
105 | - Trace version. | |
106 | - Types available. | |
6672e9e1 | 107 | - Per-trace event header description. |
3bf79539 | 108 | - Per-stream event header description. |
6672e9e1 | 109 | - Per-stream event context description. |
5ba9f198 | 110 | - Per-event |
3bf79539 | 111 | - Event type to stream mapping. |
5ba9f198 MD |
112 | - Event type to name mapping. |
113 | - Event type to ID mapping. | |
6672e9e1 | 114 | - Event context description. |
5ba9f198 MD |
115 | - Event fields description. |
116 | ||
117 | ||
3bf79539 | 118 | 3. Event stream |
5ba9f198 | 119 | |
6672e9e1 MD |
120 | An event stream can be divided into contiguous event packets of variable |
121 | size. These subdivisions have a variable size. An event packet can | |
122 | contain a certain amount of padding at the end. The stream header is | |
123 | repeated at the beginning of each event packet. The rationale for the | |
124 | event stream design choices is explained in Appendix B. Stream Header | |
125 | Rationale. | |
5ba9f198 | 126 | |
3bf79539 MD |
127 | The event stream header will therefore be referred to as the "event packet |
128 | header" throughout the rest of this document. | |
5ba9f198 MD |
129 | |
130 | ||
131 | 4. Types | |
132 | ||
1fad7a85 MD |
133 | Types are organized as type classes. Each type class belong to either of two |
134 | kind of types: basic types or compound types. | |
135 | ||
5ba9f198 MD |
136 | 4.1 Basic types |
137 | ||
1fad7a85 MD |
138 | A basic type is a scalar type, as described in this section. It includes |
139 | integers, GNU/C bitfields, enumerations, and floating point values. | |
5ba9f198 MD |
140 | |
141 | 4.1.1 Type inheritance | |
142 | ||
80fd2569 MD |
143 | Type specifications can be inherited to allow deriving types from a |
144 | type class. For example, see the uint32_t named type derived from the "integer" | |
145 | type class below ("Integers" section). Types have a precise binary | |
146 | representation in the trace. A type class has methods to read and write these | |
147 | types, but must be derived into a type to be usable in an event field. | |
5ba9f198 MD |
148 | |
149 | 4.1.2 Alignment | |
150 | ||
151 | We define "byte-packed" types as aligned on the byte size, namely 8-bit. | |
152 | We define "bit-packed" types as following on the next bit, as defined by the | |
370eae99 | 153 | "Integers" section. |
5ba9f198 | 154 | |
6672e9e1 | 155 | Each basic type must specify its alignment, in bits. Examples of |
ec4404a7 MD |
156 | possible alignments are: bit-packed (align = 1), byte-packed (align = |
157 | 8), or word-aligned (e.g. align = 32 or align = 64). The choice depends | |
158 | on the architecture preference and compactness vs performance trade-offs | |
159 | of the implementation. Architectures providing fast unaligned write | |
160 | byte-packed basic types to save space, aligning each type on byte | |
161 | boundaries (8-bit). Architectures with slow unaligned writes align types | |
162 | on specific alignment values. If no specific alignment is declared for a | |
163 | type, it is assumed to be bit-packed for integers with size not multiple | |
164 | of 8 bits and for gcc bitfields. All other basic types are byte-packed | |
165 | by default. It is however recommended to always specify the alignment | |
166 | explicitly. Alignment values must be power of two. Compound types are | |
167 | aligned as specified in their individual specification. | |
5ba9f198 | 168 | |
6672e9e1 | 169 | TSDL meta-data attribute representation of a specific alignment: |
5ba9f198 MD |
170 | |
171 | align = value; /* value in bits */ | |
172 | ||
173 | 4.1.3 Byte order | |
174 | ||
3bf79539 MD |
175 | By default, the native endianness of the source architecture the trace is used. |
176 | Byte order can be overridden for a basic type by specifying a "byte_order" | |
177 | attribute. Typical use-case is to specify the network byte order (big endian: | |
178 | "be") to save data captured from the network into the trace without conversion. | |
179 | If not specified, the byte order is native. | |
5ba9f198 | 180 | |
6672e9e1 | 181 | TSDL meta-data representation: |
5ba9f198 MD |
182 | |
183 | byte_order = native OR network OR be OR le; /* network and be are aliases */ | |
184 | ||
185 | 4.1.4 Size | |
186 | ||
187 | Type size, in bits, for integers and floats is that returned by "sizeof()" in C | |
188 | multiplied by CHAR_BIT. | |
189 | We require the size of "char" and "unsigned char" types (CHAR_BIT) to be fixed | |
190 | to 8 bits for cross-endianness compatibility. | |
191 | ||
6672e9e1 | 192 | TSDL meta-data representation: |
5ba9f198 MD |
193 | |
194 | size = value; (value is in bits) | |
195 | ||
196 | 4.1.5 Integers | |
197 | ||
6672e9e1 MD |
198 | Signed integers are represented in two-complement. Integer alignment, |
199 | size, signedness and byte ordering are defined in the TSDL meta-data. | |
200 | Integers aligned on byte size (8-bit) and with length multiple of byte | |
201 | size (8-bit) correspond to the C99 standard integers. In addition, | |
202 | integers with alignment and/or size that are _not_ a multiple of the | |
203 | byte size are permitted; these correspond to the C99 standard bitfields, | |
204 | with the added specification that the CTF integer bitfields have a fixed | |
205 | binary representation. A MIT-licensed reference implementation of the | |
206 | CTF portable bitfields is available at: | |
5ba9f198 MD |
207 | |
208 | http://git.efficios.com/?p=babeltrace.git;a=blob;f=include/babeltrace/bitfield.h | |
209 | ||
210 | Binary representation of integers: | |
211 | ||
212 | - On little and big endian: | |
213 | - Within a byte, high bits correspond to an integer high bits, and low bits | |
214 | correspond to low bits. | |
215 | - On little endian: | |
216 | - Integer across multiple bytes are placed from the less significant to the | |
217 | most significant. | |
218 | - Consecutive integers are placed from lower bits to higher bits (even within | |
219 | a byte). | |
220 | - On big endian: | |
221 | - Integer across multiple bytes are placed from the most significant to the | |
222 | less significant. | |
223 | - Consecutive integers are placed from higher bits to lower bits (even within | |
224 | a byte). | |
225 | ||
226 | This binary representation is derived from the bitfield implementation in GCC | |
227 | for little and big endian. However, contrary to what GCC does, integers can | |
6672e9e1 | 228 | cross units boundaries (no padding is required). Padding can be explicitly |
5ba9f198 MD |
229 | added (see 4.1.6 GNU/C bitfields) to follow the GCC layout if needed. |
230 | ||
6672e9e1 | 231 | TSDL meta-data representation: |
5ba9f198 | 232 | |
80fd2569 | 233 | integer { |
5ba9f198 MD |
234 | signed = true OR false; /* default false */ |
235 | byte_order = native OR network OR be OR le; /* default native */ | |
236 | size = value; /* value in bits, no default */ | |
237 | align = value; /* value in bits */ | |
56b77c06 MD |
238 | /* based used for pretty-printing output, default: decimal. */ |
239 | base = decimal OR dec OR OR d OR i OR u OR 10 OR hexadecimal OR hex OR x OR X OR p OR 16 | |
240 | OR octal OR oct OR o OR 8 OR binary OR b OR 2; | |
13441bf5 MD |
241 | /* character encoding, default: none */ |
242 | encoding = none or UTF8 or ASCII; | |
2152348f | 243 | } |
5ba9f198 | 244 | |
80fd2569 | 245 | Example of type inheritance (creation of a uint32_t named type): |
5ba9f198 | 246 | |
359894ac | 247 | typealias integer { |
9e4e34e9 | 248 | size = 32; |
5ba9f198 MD |
249 | signed = false; |
250 | align = 32; | |
38b8da21 | 251 | } := uint32_t; |
5ba9f198 | 252 | |
80fd2569 | 253 | Definition of a named 5-bit signed bitfield: |
5ba9f198 | 254 | |
359894ac | 255 | typealias integer { |
5ba9f198 MD |
256 | size = 5; |
257 | signed = true; | |
258 | align = 1; | |
38b8da21 | 259 | } := int5_t; |
5ba9f198 | 260 | |
13441bf5 MD |
261 | The character encoding field can be used to specify that the integer |
262 | must be printed as a text character when read. e.g.: | |
263 | ||
264 | typealias integer { | |
265 | size = 8; | |
266 | align = 8; | |
267 | signed = false; | |
268 | encoding = UTF8; | |
269 | } := utf_char; | |
270 | ||
271 | ||
5ba9f198 MD |
272 | 4.1.6 GNU/C bitfields |
273 | ||
274 | The GNU/C bitfields follow closely the integer representation, with a | |
275 | particularity on alignment: if a bitfield cannot fit in the current unit, the | |
80fd2569 MD |
276 | unit is padded and the bitfield starts at the following unit. The unit size is |
277 | defined by the size of the type "unit_type". | |
5ba9f198 | 278 | |
6672e9e1 | 279 | TSDL meta-data representation: |
80fd2569 | 280 | |
d674f4b8 | 281 | unit_type name:size; |
80fd2569 | 282 | |
5ba9f198 MD |
283 | As an example, the following structure declared in C compiled by GCC: |
284 | ||
285 | struct example { | |
286 | short a:12; | |
287 | short b:5; | |
288 | }; | |
289 | ||
2152348f MD |
290 | The example structure is aligned on the largest element (short). The second |
291 | bitfield would be aligned on the next unit boundary, because it would not fit in | |
292 | the current unit. | |
5ba9f198 MD |
293 | |
294 | 4.1.7 Floating point | |
295 | ||
6672e9e1 | 296 | The floating point values byte ordering is defined in the TSDL meta-data. |
5ba9f198 MD |
297 | |
298 | Floating point values follow the IEEE 754-2008 standard interchange formats. | |
299 | Description of the floating point values include the exponent and mantissa size | |
300 | in bits. Some requirements are imposed on the floating point values: | |
301 | ||
302 | - FLT_RADIX must be 2. | |
303 | - mant_dig is the number of digits represented in the mantissa. It is specified | |
304 | by the ISO C99 standard, section 5.2.4, as FLT_MANT_DIG, DBL_MANT_DIG and | |
305 | LDBL_MANT_DIG as defined by <float.h>. | |
306 | - exp_dig is the number of digits represented in the exponent. Given that | |
307 | mant_dig is one bit more than its actual size in bits (leading 1 is not | |
308 | needed) and also given that the sign bit always takes one bit, exp_dig can be | |
309 | specified as: | |
310 | ||
311 | - sizeof(float) * CHAR_BIT - FLT_MANT_DIG | |
312 | - sizeof(double) * CHAR_BIT - DBL_MANT_DIG | |
313 | - sizeof(long double) * CHAR_BIT - LDBL_MANT_DIG | |
314 | ||
6672e9e1 | 315 | TSDL meta-data representation: |
5ba9f198 | 316 | |
80fd2569 | 317 | floating_point { |
ec4404a7 MD |
318 | exp_dig = value; |
319 | mant_dig = value; | |
320 | byte_order = native OR network OR be OR le; | |
321 | align = value; | |
2152348f | 322 | } |
5ba9f198 MD |
323 | |
324 | Example of type inheritance: | |
325 | ||
359894ac | 326 | typealias floating_point { |
5ba9f198 MD |
327 | exp_dig = 8; /* sizeof(float) * CHAR_BIT - FLT_MANT_DIG */ |
328 | mant_dig = 24; /* FLT_MANT_DIG */ | |
329 | byte_order = native; | |
ec4404a7 | 330 | align = 32; |
38b8da21 | 331 | } := float; |
5ba9f198 MD |
332 | |
333 | TODO: define NaN, +inf, -inf behavior. | |
334 | ||
ec4404a7 MD |
335 | Bit-packed, byte-packed or larger alignments can be used for floating |
336 | point values, similarly to integers. | |
337 | ||
5ba9f198 MD |
338 | 4.1.8 Enumerations |
339 | ||
340 | Enumerations are a mapping between an integer type and a table of strings. The | |
341 | numerical representation of the enumeration follows the integer type specified | |
6672e9e1 MD |
342 | by the meta-data. The enumeration mapping table is detailed in the enumeration |
343 | description within the meta-data. The mapping table maps inclusive value | |
344 | ranges (or single values) to strings. Instead of being limited to simple | |
3bf79539 | 345 | "value -> string" mappings, these enumerations map |
80fd2569 | 346 | "[ start_value ... end_value ] -> string", which map inclusive ranges of |
3bf79539 MD |
347 | values to strings. An enumeration from the C language can be represented in |
348 | this format by having the same start_value and end_value for each element, which | |
349 | is in fact a range of size 1. This single-value range is supported without | |
4767a9e7 | 350 | repeating the start and end values with the value = string declaration. |
80fd2569 | 351 | |
a9b83695 | 352 | enum name : integer_type { |
359894ac | 353 | somestring = start_value1 ... end_value1, |
80fd2569 MD |
354 | "other string" = start_value2 ... end_value2, |
355 | yet_another_string, /* will be assigned to end_value2 + 1 */ | |
356 | "some other string" = value, | |
357 | ... | |
358 | }; | |
359 | ||
360 | If the values are omitted, the enumeration starts at 0 and increment of 1 for | |
361 | each entry: | |
362 | ||
a9b83695 | 363 | enum name : unsigned int { |
80fd2569 MD |
364 | ZERO, |
365 | ONE, | |
366 | TWO, | |
367 | TEN = 10, | |
368 | ELEVEN, | |
3bf79539 | 369 | }; |
5ba9f198 | 370 | |
80fd2569 | 371 | Overlapping ranges within a single enumeration are implementation defined. |
5ba9f198 | 372 | |
2152348f MD |
373 | A nameless enumeration can be declared as a field type or as part of a typedef: |
374 | ||
a9b83695 | 375 | enum : integer_type { |
2152348f MD |
376 | ... |
377 | } | |
378 | ||
c2742c56 MD |
379 | Enumerations omitting the container type ": integer_type" use the "int" |
380 | type (for compatibility with C99). The "int" type must be previously | |
381 | declared. E.g.: | |
382 | ||
383 | typealias integer { size = 32; align = 32; signed = true } := int; | |
384 | ||
385 | enum { | |
386 | ... | |
387 | } | |
388 | ||
1fad7a85 | 389 | |
5ba9f198 MD |
390 | 4.2 Compound types |
391 | ||
1fad7a85 MD |
392 | Compound are aggregation of type declarations. Compound types include |
393 | structures, variant, arrays, sequences, and strings. | |
394 | ||
5ba9f198 MD |
395 | 4.2.1 Structures |
396 | ||
397 | Structures are aligned on the largest alignment required by basic types | |
398 | contained within the structure. (This follows the ISO/C standard for structures) | |
399 | ||
6672e9e1 | 400 | TSDL meta-data representation of a named structure: |
5ba9f198 | 401 | |
80fd2569 MD |
402 | struct name { |
403 | field_type field_name; | |
404 | field_type field_name; | |
405 | ... | |
406 | }; | |
5ba9f198 MD |
407 | |
408 | Example: | |
409 | ||
80fd2569 MD |
410 | struct example { |
411 | integer { /* Nameless type */ | |
412 | size = 16; | |
413 | signed = true; | |
414 | align = 16; | |
415 | } first_field_name; | |
6672e9e1 | 416 | uint64_t second_field_name; /* Named type declared in the meta-data */ |
3bf79539 | 417 | }; |
5ba9f198 | 418 | |
4cac83ee MD |
419 | The fields are placed in a sequence next to each other. They each |
420 | possess a field name, which is a unique identifier within the structure. | |
421 | The identifier is not allowed to use any reserved keyword | |
422 | (see Section C.1.2). Replacing reserved keywords with | |
70375f92 MD |
423 | underscore-prefixed field names is recommended. Fields starting with an |
424 | underscore should have their leading underscore removed by the CTF parser. | |
5ba9f198 | 425 | |
2152348f | 426 | A nameless structure can be declared as a field type or as part of a typedef: |
80fd2569 MD |
427 | |
428 | struct { | |
429 | ... | |
2152348f | 430 | } |
80fd2569 | 431 | |
ec4404a7 MD |
432 | Alignment for a structure compound type can be forced to a minimum value |
433 | by adding an "align" specifier after the declaration of a structure | |
434 | body. This attribute is read as: align(value). The value is specified in | |
435 | bits. The structure will be aligned on the maximum value between this | |
436 | attribute and the alignment required by the basic types contained within | |
437 | the structure. e.g. | |
438 | ||
439 | struct { | |
440 | ... | |
441 | } align(32) | |
442 | ||
77a98c82 | 443 | 4.2.2 Variants (Discriminated/Tagged Unions) |
fcba70d4 | 444 | |
fdf2bb05 MD |
445 | A CTF variant is a selection between different types. A CTF variant must |
446 | always be defined within the scope of a structure or within fields | |
447 | contained within a structure (defined recursively). A "tag" enumeration | |
37ab95c3 MD |
448 | field must appear in either the same static scope, prior to the variant |
449 | field (in field declaration order), in an upper static scope , or in an | |
450 | upper dynamic scope (see Section 7.3.2). The type selection is indicated | |
451 | by the mapping from the enumeration value to the string used as variant | |
452 | type selector. The field to use as tag is specified by the "tag_field", | |
453 | specified between "< >" after the "variant" keyword for unnamed | |
454 | variants, and after "variant name" for named variants. | |
fcba70d4 MD |
455 | |
456 | The alignment of the variant is the alignment of the type as selected by the tag | |
457 | value for the specific instance of the variant. The alignment of the type | |
458 | containing the variant is independent of the variant alignment. The size of the | |
459 | variant is the size as selected by the tag value for the specific instance of | |
460 | the variant. | |
461 | ||
4cac83ee MD |
462 | Each variant type selector possess a field name, which is a unique |
463 | identifier within the variant. The identifier is not allowed to use any | |
464 | reserved keyword (see Section C.1.2). Replacing reserved keywords with | |
70375f92 MD |
465 | underscore-prefixed field names is recommended. Fields starting with an |
466 | underscore should have their leading underscore removed by the CTF parser. | |
467 | ||
4cac83ee | 468 | |
fcba70d4 MD |
469 | A named variant declaration followed by its definition within a structure |
470 | declaration: | |
471 | ||
472 | variant name { | |
473 | field_type sel1; | |
474 | field_type sel2; | |
475 | field_type sel3; | |
476 | ... | |
477 | }; | |
478 | ||
479 | struct { | |
a9b83695 | 480 | enum : integer_type { sel1, sel2, sel3, ... } tag_field; |
fcba70d4 MD |
481 | ... |
482 | variant name <tag_field> v; | |
483 | } | |
484 | ||
485 | An unnamed variant definition within a structure is expressed by the following | |
6672e9e1 | 486 | TSDL meta-data: |
fcba70d4 MD |
487 | |
488 | struct { | |
a9b83695 | 489 | enum : integer_type { sel1, sel2, sel3, ... } tag_field; |
fcba70d4 MD |
490 | ... |
491 | variant <tag_field> { | |
492 | field_type sel1; | |
493 | field_type sel2; | |
494 | field_type sel3; | |
495 | ... | |
496 | } v; | |
497 | } | |
498 | ||
499 | Example of a named variant within a sequence that refers to a single tag field: | |
500 | ||
501 | variant example { | |
502 | uint32_t a; | |
503 | uint64_t b; | |
504 | short c; | |
505 | }; | |
506 | ||
507 | struct { | |
a9b83695 | 508 | enum : uint2_t { a, b, c } choice; |
1ab22b2a MD |
509 | unsigned int seqlen; |
510 | variant example <choice> v[seqlen]; | |
fcba70d4 MD |
511 | } |
512 | ||
513 | Example of an unnamed variant: | |
514 | ||
515 | struct { | |
a9b83695 | 516 | enum : uint2_t { a, b, c, d } choice; |
fcba70d4 MD |
517 | /* Unrelated fields can be added between the variant and its tag */ |
518 | int32_t somevalue; | |
519 | variant <choice> { | |
520 | uint32_t a; | |
521 | uint64_t b; | |
522 | short c; | |
523 | struct { | |
524 | unsigned int field1; | |
525 | uint64_t field2; | |
526 | } d; | |
527 | } s; | |
528 | } | |
529 | ||
530 | Example of an unnamed variant within an array: | |
531 | ||
532 | struct { | |
a9b83695 | 533 | enum : uint2_t { a, b, c } choice; |
fcba70d4 MD |
534 | variant <choice> { |
535 | uint32_t a; | |
536 | uint64_t b; | |
537 | short c; | |
15850440 | 538 | } v[10]; |
fcba70d4 MD |
539 | } |
540 | ||
541 | Example of a variant type definition within a structure, where the defined type | |
542 | is then declared within an array of structures. This variant refers to a tag | |
37ab95c3 | 543 | located in an upper static scope. This example clearly shows that a variant |
fcba70d4 | 544 | type definition referring to the tag "x" uses the closest preceding field from |
37ab95c3 | 545 | the static scope of the type definition. |
fcba70d4 MD |
546 | |
547 | struct { | |
a9b83695 | 548 | enum : uint2_t { a, b, c, d } x; |
fcba70d4 MD |
549 | |
550 | typedef variant <x> { /* | |
551 | * "x" refers to the preceding "x" enumeration in the | |
37ab95c3 | 552 | * static scope of the type definition. |
fcba70d4 MD |
553 | */ |
554 | uint32_t a; | |
555 | uint64_t b; | |
556 | short c; | |
557 | } example_variant; | |
558 | ||
559 | struct { | |
a9b83695 | 560 | enum : int { x, y, z } x; /* This enumeration is not used by "v". */ |
fcba70d4 | 561 | example_variant v; /* |
a9b83695 | 562 | * "v" uses the "enum : uint2_t { a, b, c, d }" |
fcba70d4 MD |
563 | * tag. |
564 | */ | |
565 | } a[10]; | |
566 | } | |
567 | ||
568 | 4.2.3 Arrays | |
5ba9f198 | 569 | |
6672e9e1 MD |
570 | Arrays are fixed-length. Their length is declared in the type |
571 | declaration within the meta-data. They contain an array of "inner type" | |
572 | elements, which can refer to any type not containing the type of the | |
573 | array being declared (no circular dependency). The length is the number | |
574 | of elements in an array. | |
5ba9f198 | 575 | |
6672e9e1 | 576 | TSDL meta-data representation of a named array: |
80fd2569 MD |
577 | |
578 | typedef elem_type name[length]; | |
5ba9f198 | 579 | |
2152348f | 580 | A nameless array can be declared as a field type within a structure, e.g.: |
5ba9f198 | 581 | |
2152348f | 582 | uint8_t field_name[10]; |
80fd2569 | 583 | |
ec4404a7 | 584 | Arrays are always aligned on their element alignment requirement. |
5ba9f198 | 585 | |
fcba70d4 | 586 | 4.2.4 Sequences |
5ba9f198 | 587 | |
1ab22b2a | 588 | Sequences are dynamically-sized arrays. They refer to a a "length" |
37ab95c3 | 589 | unsigned integer field, which must appear in either the same static scope, |
1ab22b2a | 590 | prior to the sequence field (in field declaration order), in an upper |
37ab95c3 MD |
591 | static scope, or in an upper dynamic scope (see Section 7.3.2). This |
592 | length field represents the number of elements in the sequence. The | |
593 | sequence per se is an array of "inner type" elements. | |
5ba9f198 | 594 | |
1ab22b2a | 595 | TSDL meta-data representation for a sequence type definition: |
80fd2569 | 596 | |
1ab22b2a MD |
597 | struct { |
598 | unsigned int length_field; | |
599 | typedef elem_type typename[length_field]; | |
600 | typename seq_field_name; | |
601 | } | |
602 | ||
603 | A sequence can also be declared as a field type, e.g.: | |
80fd2569 | 604 | |
1ab22b2a MD |
605 | struct { |
606 | unsigned int length_field; | |
607 | long seq_field_name[length_field]; | |
608 | } | |
80fd2569 | 609 | |
1ab22b2a MD |
610 | Multiple sequences can refer to the same length field, and these length |
611 | fields can be in a different upper dynamic scope: | |
612 | ||
613 | e.g., assuming the stream.event.header defines: | |
614 | ||
615 | stream { | |
616 | ... | |
617 | id = 1; | |
618 | event.header := struct { | |
619 | uint16_t seq_len; | |
620 | }; | |
621 | }; | |
622 | ||
623 | event { | |
624 | ... | |
625 | stream_id = 1; | |
626 | fields := struct { | |
627 | long seq_a[stream.event.header.seq_len]; | |
628 | char seq_b[stream.event.header.seq_len]; | |
629 | }; | |
630 | }; | |
80fd2569 | 631 | |
1ab22b2a | 632 | The sequence elements follow the "array" specifications. |
5ba9f198 | 633 | |
fcba70d4 | 634 | 4.2.5 Strings |
5ba9f198 MD |
635 | |
636 | Strings are an array of bytes of variable size and are terminated by a '\0' | |
6672e9e1 MD |
637 | "NULL" character. Their encoding is described in the TSDL meta-data. In |
638 | absence of encoding attribute information, the default encoding is | |
639 | UTF-8. | |
5ba9f198 | 640 | |
6672e9e1 | 641 | TSDL meta-data representation of a named string type: |
80fd2569 | 642 | |
359894ac | 643 | typealias string { |
5ba9f198 | 644 | encoding = UTF8 OR ASCII; |
38b8da21 | 645 | } := name; |
5ba9f198 | 646 | |
80fd2569 MD |
647 | A nameless string type can be declared as a field type: |
648 | ||
649 | string field_name; /* Use default UTF8 encoding */ | |
5ba9f198 | 650 | |
ec4404a7 MD |
651 | Strings are always aligned on byte size. |
652 | ||
3bf79539 MD |
653 | 5. Event Packet Header |
654 | ||
6672e9e1 MD |
655 | The event packet header consists of two parts: the "event packet header" |
656 | is the same for all streams of a trace. The second part, the "event | |
657 | packet context", is described on a per-stream basis. Both are described | |
658 | in the TSDL meta-data. The packets are aligned on architecture-page-sized | |
659 | addresses. | |
3bf79539 | 660 | |
6672e9e1 | 661 | Event packet header (all fields are optional, specified by TSDL meta-data): |
3bf79539 | 662 | |
6672e9e1 MD |
663 | - Magic number (CTF magic number: 0xC1FC1FC1) specifies that this is a |
664 | CTF packet. This magic number is optional, but when present, it should | |
665 | come at the very beginning of the packet. | |
666 | - Trace UUID, used to ensure the event packet match the meta-data used. | |
667 | (note: we cannot use a meta-data checksum in every cases instead of a | |
668 | UUID because meta-data can be appended to while tracing is active) | |
669 | This field is optional. | |
670 | - Stream ID, used as reference to stream description in meta-data. | |
671 | This field is optional if there is only one stream description in the | |
672 | meta-data, but becomes required if there are more than one stream in | |
673 | the TSDL meta-data description. | |
3bf79539 | 674 | |
6672e9e1 | 675 | Event packet context (all fields are optional, specified by TSDL meta-data): |
3bf79539 | 676 | |
4dfca05b MD |
677 | - Event packet content size (in bits). |
678 | - Event packet size (in bits, includes padding). | |
cda89682 | 679 | - Event packet content checksum. Checksum excludes the event packet |
3bf79539 MD |
680 | header. |
681 | - Per-stream event packet sequence count (to deal with UDP packet loss). The | |
682 | number of significant sequence counter bits should also be present, so | |
b11853af | 683 | wrap-arounds are dealt with correctly. |
6672e9e1 | 684 | - Time-stamp at the beginning and time-stamp at the end of the event packet. |
3bf79539 MD |
685 | Both timestamps are written in the packet header, but sampled respectively |
686 | while (or before) writing the first event and while (or after) writing the | |
687 | last event in the packet. The inclusive range between these timestamps should | |
688 | include all event timestamps assigned to events contained within the packet. | |
5ba9f198 | 689 | - Events discarded count |
3bf79539 MD |
690 | - Snapshot of a per-stream free-running counter, counting the number of |
691 | events discarded that were supposed to be written in the stream prior to | |
692 | the first event in the event packet. | |
5ba9f198 | 693 | * Note: producer-consumer buffer full condition should fill the current |
3bf79539 | 694 | event packet with padding so we know exactly where events have been |
5ba9f198 | 695 | discarded. |
3bf79539 MD |
696 | - Lossless compression scheme used for the event packet content. Applied |
697 | directly to raw data. New types of compression can be added in following | |
698 | versions of the format. | |
5ba9f198 MD |
699 | 0: no compression scheme |
700 | 1: bzip2 | |
701 | 2: gzip | |
3bf79539 MD |
702 | 3: xz |
703 | - Cypher used for the event packet content. Applied after compression. | |
5ba9f198 MD |
704 | 0: no encryption |
705 | 1: AES | |
3bf79539 | 706 | - Checksum scheme used for the event packet content. Applied after encryption. |
5ba9f198 MD |
707 | 0: no checksum |
708 | 1: md5 | |
709 | 2: sha1 | |
710 | 3: crc32 | |
711 | ||
6672e9e1 | 712 | 5.1 Event Packet Header Description |
3bf79539 | 713 | |
fc5425db | 714 | The event packet header layout is indicated by the trace packet.header |
6672e9e1 MD |
715 | field. Here is a recommended structure type for the packet header with |
716 | the fields typically expected (although these fields are each optional): | |
fc5425db | 717 | |
80fd2569 MD |
718 | struct event_packet_header { |
719 | uint32_t magic; | |
3fde5da1 | 720 | uint8_t uuid[16]; |
3bf79539 | 721 | uint32_t stream_id; |
80fd2569 | 722 | }; |
5ba9f198 | 723 | |
fc5425db MD |
724 | trace { |
725 | ... | |
726 | packet.header := struct event_packet_header; | |
727 | }; | |
728 | ||
6672e9e1 MD |
729 | If the magic number is not present, tools such as "file" will have no |
730 | mean to discover the file type. | |
731 | ||
3fde5da1 MD |
732 | If the uuid is not present, no validation that the meta-data actually |
733 | corresponds to the stream is performed. | |
37b39e47 MD |
734 | |
735 | If the stream_id packet header field is missing, the trace can only | |
736 | contain a single stream. Its "id" field can be left out, and its events | |
737 | don't need to declare a "stream_id" field. | |
738 | ||
739 | ||
3bf79539 MD |
740 | 5.2 Event Packet Context Description |
741 | ||
742 | Event packet context example. These are declared within the stream declaration | |
6672e9e1 | 743 | in the meta-data. All these fields are optional. If the packet size field is |
6a7c61df | 744 | missing, the whole stream only contains a single packet. If the content |
f6b81726 MD |
745 | size field is missing, the packet is filled (no padding). The content |
746 | and packet sizes include all headers. | |
3bf79539 MD |
747 | |
748 | An example event packet context type: | |
749 | ||
80fd2569 | 750 | struct event_packet_context { |
3bf79539 MD |
751 | uint64_t timestamp_begin; |
752 | uint64_t timestamp_end; | |
753 | uint32_t checksum; | |
754 | uint32_t stream_packet_count; | |
755 | uint32_t events_discarded; | |
756 | uint32_t cpu_id; | |
757 | uint32_t/uint16_t content_size; | |
758 | uint32_t/uint16_t packet_size; | |
3bf79539 MD |
759 | uint8_t compression_scheme; |
760 | uint8_t encryption_scheme; | |
3b0f8e4d | 761 | uint8_t checksum_scheme; |
3bf79539 | 762 | }; |
5ba9f198 | 763 | |
fcba70d4 | 764 | |
5ba9f198 MD |
765 | 6. Event Structure |
766 | ||
767 | The overall structure of an event is: | |
768 | ||
6672e9e1 MD |
769 | 1 - Stream Packet Context (as specified by the stream meta-data) |
770 | 2 - Event Header (as specified by the stream meta-data) | |
771 | 3 - Stream Event Context (as specified by the stream meta-data) | |
772 | 4 - Event Context (as specified by the event meta-data) | |
773 | 5 - Event Payload (as specified by the event meta-data) | |
5ba9f198 | 774 | |
fdf2bb05 | 775 | This structure defines an implicit dynamic scoping, where variants |
7d9d7e92 MD |
776 | located in inner structures (those with a higher number in the listing |
777 | above) can refer to the fields of outer structures (with lower number in | |
6c7226e9 | 778 | the listing above). See Section 7.3 TSDL Scopes for more detail. |
5ba9f198 | 779 | |
fdf2bb05 | 780 | 6.1 Event Header |
fcba70d4 | 781 | |
6672e9e1 | 782 | Event headers can be described within the meta-data. We hereby propose, as an |
fcba70d4 MD |
783 | example, two types of events headers. Type 1 accommodates streams with less than |
784 | 31 event IDs. Type 2 accommodates streams with 31 or more event IDs. | |
5ba9f198 | 785 | |
3bf79539 MD |
786 | One major factor can vary between streams: the number of event IDs assigned to |
787 | a stream. Luckily, this information tends to stay relatively constant (modulo | |
5ba9f198 | 788 | event registration while trace is being recorded), so we can specify different |
3bf79539 | 789 | representations for streams containing few event IDs and streams containing |
6672e9e1 MD |
790 | many event IDs, so we end up representing the event ID and time-stamp as |
791 | densely as possible in each case. | |
5ba9f198 | 792 | |
fcba70d4 MD |
793 | The header is extended in the rare occasions where the information cannot be |
794 | represented in the ranges available in the standard event header. They are also | |
3bf79539 MD |
795 | used in the rare occasions where the data required for a field could not be |
796 | collected: the flag corresponding to the missing field within the missing_fields | |
797 | array is then set to 1. | |
5ba9f198 | 798 | |
6672e9e1 MD |
799 | Types uintX_t represent an X-bit unsigned integer, as declared with |
800 | either: | |
5ba9f198 | 801 | |
6672e9e1 MD |
802 | typealias integer { size = X; align = X; signed = false } := uintX_t; |
803 | ||
804 | or | |
805 | ||
806 | typealias integer { size = X; align = 1; signed = false } := uintX_t; | |
5ba9f198 | 807 | |
fdf2bb05 | 808 | 6.1.1 Type 1 - Few event IDs |
5ba9f198 MD |
809 | |
810 | - Aligned on 32-bit (or 8-bit if byte-packed, depending on the architecture | |
811 | preference). | |
5ba9f198 | 812 | - Native architecture byte ordering. |
fcba70d4 MD |
813 | - For "compact" selection |
814 | - Fixed size: 32 bits. | |
815 | - For "extended" selection | |
816 | - Size depends on the architecture and variant alignment. | |
5ba9f198 | 817 | |
80fd2569 | 818 | struct event_header_1 { |
fcba70d4 MD |
819 | /* |
820 | * id: range: 0 - 30. | |
821 | * id 31 is reserved to indicate an extended header. | |
822 | */ | |
a9b83695 | 823 | enum : uint5_t { compact = 0 ... 30, extended = 31 } id; |
fcba70d4 MD |
824 | variant <id> { |
825 | struct { | |
826 | uint27_t timestamp; | |
827 | } compact; | |
828 | struct { | |
829 | uint32_t id; /* 32-bit event IDs */ | |
830 | uint64_t timestamp; /* 64-bit timestamps */ | |
831 | } extended; | |
832 | } v; | |
cb108fea | 833 | } align(32); /* or align(8) */ |
5ba9f198 | 834 | |
5ba9f198 | 835 | |
fdf2bb05 | 836 | 6.1.2 Type 2 - Many event IDs |
5ba9f198 | 837 | |
fcba70d4 | 838 | - Aligned on 16-bit (or 8-bit if byte-packed, depending on the architecture |
5ba9f198 | 839 | preference). |
5ba9f198 | 840 | - Native architecture byte ordering. |
fcba70d4 MD |
841 | - For "compact" selection |
842 | - Size depends on the architecture and variant alignment. | |
843 | - For "extended" selection | |
844 | - Size depends on the architecture and variant alignment. | |
5ba9f198 | 845 | |
80fd2569 | 846 | struct event_header_2 { |
fcba70d4 MD |
847 | /* |
848 | * id: range: 0 - 65534. | |
849 | * id 65535 is reserved to indicate an extended header. | |
850 | */ | |
a9b83695 | 851 | enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id; |
fcba70d4 MD |
852 | variant <id> { |
853 | struct { | |
854 | uint32_t timestamp; | |
855 | } compact; | |
856 | struct { | |
857 | uint32_t id; /* 32-bit event IDs */ | |
858 | uint64_t timestamp; /* 64-bit timestamps */ | |
859 | } extended; | |
860 | } v; | |
cb108fea | 861 | } align(16); /* or align(8) */ |
5ba9f198 | 862 | |
5ba9f198 MD |
863 | |
864 | 6.2 Event Context | |
865 | ||
6672e9e1 MD |
866 | The event context contains information relative to the current event. |
867 | The choice and meaning of this information is specified by the TSDL | |
868 | stream and event meta-data descriptions. The stream context is applied | |
869 | to all events within the stream. The stream context structure follows | |
870 | the event header. The event context is applied to specific events. Its | |
871 | structure follows the stream context structure. | |
5ba9f198 | 872 | |
fcba70d4 MD |
873 | An example of stream-level event context is to save the event payload size with |
874 | each event, or to save the current PID with each event. These are declared | |
6672e9e1 | 875 | within the stream declaration within the meta-data: |
5ba9f198 | 876 | |
fcba70d4 MD |
877 | stream { |
878 | ... | |
6672e9e1 | 879 | event.context := struct { |
80fd2569 MD |
880 | uint pid; |
881 | uint16_t payload_size; | |
6672e9e1 | 882 | }; |
fcba70d4 MD |
883 | }; |
884 | ||
885 | An example of event-specific event context is to declare a bitmap of missing | |
886 | fields, only appended after the stream event context if the extended event | |
887 | header is selected. NR_FIELDS is the number of fields within the event (a | |
888 | numeric value). | |
5ba9f198 | 889 | |
fcba70d4 MD |
890 | event { |
891 | context = struct { | |
892 | variant <id> { | |
893 | struct { } compact; | |
894 | struct { | |
895 | uint1_t missing_fields[NR_FIELDS]; /* missing event fields bitmap */ | |
896 | } extended; | |
897 | } v; | |
898 | }; | |
899 | ... | |
900 | } | |
5ba9f198 MD |
901 | |
902 | 6.3 Event Payload | |
903 | ||
904 | An event payload contains fields specific to a given event type. The fields | |
6672e9e1 | 905 | belonging to an event type are described in the event-specific meta-data |
5ba9f198 MD |
906 | within a structure type. |
907 | ||
908 | 6.3.1 Padding | |
909 | ||
910 | No padding at the end of the event payload. This differs from the ISO/C standard | |
911 | for structures, but follows the CTF standard for structures. In a trace, even | |
912 | though it makes sense to align the beginning of a structure, it really makes no | |
913 | sense to add padding at the end of the structure, because structures are usually | |
914 | not followed by a structure of the same type. | |
915 | ||
916 | This trick can be done by adding a zero-length "end" field at the end of the C | |
917 | structures, and by using the offset of this field rather than using sizeof() | |
3bf79539 | 918 | when calculating the size of a structure (see Appendix "A. Helper macros"). |
5ba9f198 MD |
919 | |
920 | 6.3.2 Alignment | |
921 | ||
922 | The event payload is aligned on the largest alignment required by types | |
923 | contained within the payload. (This follows the ISO/C standard for structures) | |
924 | ||
925 | ||
6c7226e9 MD |
926 | 7. Trace Stream Description Language (TSDL) |
927 | ||
928 | The Trace Stream Description Language (TSDL) allows expression of the | |
929 | binary trace streams layout in a C99-like Domain Specific Language | |
930 | (DSL). | |
931 | ||
932 | ||
6672e9e1 | 933 | 7.1 Meta-data |
6c7226e9 MD |
934 | |
935 | The trace stream layout description is located in the trace meta-data. | |
936 | The meta-data is itself located in a stream identified by its name: | |
937 | "metadata". | |
5ba9f198 | 938 | |
6672e9e1 MD |
939 | The meta-data description can be expressed in two different formats: |
940 | text-only and packet-based. The text-only description facilitates | |
941 | generation of meta-data and provides a convenient way to enter the | |
942 | meta-data information by hand. The packet-based meta-data provides the | |
943 | CTF stream packet facilities (checksumming, compression, encryption, | |
944 | network-readiness) for meta-data stream generated and transported by a | |
945 | tracer. | |
946 | ||
1b4d35eb MD |
947 | The text-only meta-data file is a plain-text TSDL description. This file |
948 | must begin with the following characters to identify the file as a CTF | |
9486a18c | 949 | TSDL text-based metadata file (without the double-quotes) : |
1b4d35eb | 950 | |
ec2b4db8 | 951 | "/* CTF" |
1b4d35eb | 952 | |
ec2b4db8 MD |
953 | It must be followed by a space, and the version of the specification |
954 | followed by the CTF trace, e.g.: | |
955 | ||
956 | " 1.8" | |
957 | ||
958 | These characters allow automated discovery of file type and CTF | |
959 | specification version. They are interpreted as a the beginning of a | |
960 | comment by the TSDL metadata parser. The comment can be continued to | |
961 | contain extra commented characters before it is closed. | |
6672e9e1 MD |
962 | |
963 | The packet-based meta-data is made of "meta-data packets", which each | |
964 | start with a meta-data packet header. The packet-based meta-data | |
965 | description is detected by reading the magic number "0x75D11D57" at the | |
966 | beginning of the file. This magic number is also used to detect the | |
967 | endianness of the architecture by trying to read the CTF magic number | |
968 | and its counterpart in reversed endianness. The events within the | |
969 | meta-data stream have no event header nor event context. Each event only | |
5ae2352d | 970 | contains a "sequence" payload, which is a sequence of bits using the |
ce2228da MD |
971 | "trace.packet.header.content_size" field as a placeholder for its length |
972 | (the packet header size should be substracted). The formatting of this | |
973 | sequence of bits is a plain-text representation of the TSDL description. | |
974 | Each meta-data packet start with a special packet header, specific to | |
975 | the meta-data stream, which contains, exactly: | |
6672e9e1 MD |
976 | |
977 | struct metadata_packet_header { | |
2daeaa3a | 978 | uint32_t magic; /* 0x75D11D57 */ |
3fde5da1 | 979 | uint8_t uuid[16]; /* Unique Universal Identifier */ |
6672e9e1 MD |
980 | uint32_t checksum; /* 0 if unused */ |
981 | uint32_t content_size; /* in bits */ | |
982 | uint32_t packet_size; /* in bits */ | |
983 | uint8_t compression_scheme; /* 0 if unused */ | |
984 | uint8_t encryption_scheme; /* 0 if unused */ | |
985 | uint8_t checksum_scheme; /* 0 if unused */ | |
ec2b4db8 MD |
986 | uint8_t major; /* CTF spec version major number */ |
987 | uint8_t minor; /* CTF spec version minor number */ | |
6672e9e1 MD |
988 | }; |
989 | ||
990 | The packet-based meta-data can be converted to a text-only meta-data by | |
991 | concatenating all the strings in contains. | |
4fafe1ad | 992 | |
6672e9e1 MD |
993 | In the textual representation of the meta-data, the text contained |
994 | within "/*" and "*/", as well as within "//" and end of line, are | |
995 | treated as comments. Boolean values can be represented as true, TRUE, | |
996 | or 1 for true, and false, FALSE, or 0 for false. Within the string-based | |
997 | meta-data description, the trace UUID is represented as a string of | |
998 | hexadecimal digits and dashes "-". In the event packet header, the trace | |
999 | UUID is represented as an array of bytes. | |
fcba70d4 | 1000 | |
fdf2bb05 | 1001 | |
6c7226e9 | 1002 | 7.2 Declaration vs Definition |
fdf2bb05 MD |
1003 | |
1004 | A declaration associates a layout to a type, without specifying where | |
1005 | this type is located in the event structure hierarchy (see Section 6). | |
1006 | This therefore includes typedef, typealias, as well as all type | |
1007 | specifiers. In certain circumstances (typedef, structure field and | |
1008 | variant field), a declaration is followed by a declarator, which specify | |
1009 | the newly defined type name (for typedef), or the field name (for | |
1010 | declarations located within structure and variants). Array and sequence, | |
1011 | declared with square brackets ("[" "]"), are part of the declarator, | |
a9b83695 | 1012 | similarly to C99. The enumeration base type is specified by |
6c7226e9 | 1013 | ": enum_base", which is part of the type specifier. The variant tag |
a9b83695 | 1014 | name, specified between "<" ">", is also part of the type specifier. |
fdf2bb05 MD |
1015 | |
1016 | A definition associates a type to a location in the event structure | |
b9606a77 MD |
1017 | hierarchy (see Section 6). This association is denoted by ":=", as shown |
1018 | in Section 7.3. | |
fdf2bb05 MD |
1019 | |
1020 | ||
6c7226e9 | 1021 | 7.3 TSDL Scopes |
fdf2bb05 | 1022 | |
37ab95c3 MD |
1023 | TSDL uses three different types of scoping: a lexical scope is used for |
1024 | declarations and type definitions, and static and dynamic scopes are | |
1025 | used for variants references to tag fields (with relative and absolute | |
1026 | path lookups) and for sequence references to length fields. | |
fdf2bb05 | 1027 | |
6c7226e9 | 1028 | 7.3.1 Lexical Scope |
fdf2bb05 | 1029 | |
d285084f MD |
1030 | Each of "trace", "stream", "event", "struct" and "variant" have their own |
1031 | nestable declaration scope, within which types can be declared using "typedef" | |
fdf2bb05 | 1032 | and "typealias". A root declaration scope also contains all declarations |
7d9d7e92 | 1033 | located outside of any of the aforementioned declarations. An inner |
fdf2bb05 | 1034 | declaration scope can refer to type declared within its container |
7d9d7e92 MD |
1035 | lexical scope prior to the inner declaration scope. Redefinition of a |
1036 | typedef or typealias is not valid, although hiding an upper scope | |
fdf2bb05 MD |
1037 | typedef or typealias is allowed within a sub-scope. |
1038 | ||
37ab95c3 | 1039 | 7.3.2 Static and Dynamic Scopes |
fdf2bb05 | 1040 | |
37ab95c3 MD |
1041 | A local static scope consists in the scope generated by the declaration |
1042 | of fields within a compound type. A static scope is a local static scope | |
1043 | augmented with the nested sub-static-scopes it contains. | |
1044 | ||
1045 | A dynamic scope consists in the static scope augmented with the | |
7d9d7e92 | 1046 | implicit event structure definition hierarchy presented at Section 6. |
fdf2bb05 | 1047 | |
37ab95c3 MD |
1048 | Multiple declarations of the same field name within a local static scope |
1049 | is not valid. It is however valid to re-use the same field name in | |
1050 | different local scopes. | |
1051 | ||
1052 | Nested static and dynamic scopes form lookup paths. These are used for | |
1053 | variant tag and sequence length references. They are used at the variant | |
1054 | and sequence definition site to look up the location of the tag field | |
1055 | associated with a variant, and to lookup up the location of the length | |
1056 | field associated with a sequence. | |
1057 | ||
1058 | Variants and sequences can refer to a tag field either using a relative | |
4cac83ee MD |
1059 | path or an absolute path. The relative path is relative to the scope in |
1060 | which the variant or sequence performing the lookup is located. | |
37ab95c3 MD |
1061 | Relative paths are only allowed to lookup within the same static scope, |
1062 | which includes its nested static scopes. Lookups targeting parent static | |
1063 | scopes need to be performed with an absolute path. | |
1064 | ||
1065 | Absolute path lookups use the full path including the dynamic scope | |
1066 | followed by a "." and then the static scope. Therefore, variants (or | |
1067 | sequences) in lower levels in the dynamic scope (e.g. event context) can | |
1068 | refer to a tag (or length) field located in upper levels (e.g. in the | |
1069 | event header) by specifying, in this case, the associated tag with | |
1070 | <stream.event.header.field_name>. This allows, for instance, the event | |
1071 | context to define a variant referring to the "id" field of the event | |
1072 | header as selector. | |
1073 | ||
284724ae | 1074 | The dynamic scope prefixes are thus: |
fdf2bb05 | 1075 | |
e0d9e2c7 | 1076 | - Trace Packet Header: <trace.packet.header. >, |
7d9d7e92 MD |
1077 | - Stream Packet Context: <stream.packet.context. >, |
1078 | - Event Header: <stream.event.header. >, | |
1079 | - Stream Event Context: <stream.event.context. >, | |
1080 | - Event Context: <event.context. >, | |
1081 | - Event Payload: <event.fields. >. | |
fdf2bb05 | 1082 | |
37ab95c3 MD |
1083 | |
1084 | The target dynamic scope must be specified explicitly when referring to | |
4cac83ee MD |
1085 | a field outside of the static scope (absolute scope reference). No |
1086 | conflict can occur between relative and dynamic paths, because the | |
1087 | keywords "trace", "stream", and "event" are reserved, and thus | |
1088 | not permitted as field names. It is recommended that field names | |
1089 | clashing with CTF and C99 reserved keywords use an underscore prefix to | |
1090 | eliminate the risk of generating a description containing an invalid | |
70375f92 MD |
1091 | field name. Consequently, fields starting with an underscore should have |
1092 | their leading underscore removed by the CTF parser. | |
1093 | ||
fdf2bb05 | 1094 | |
457d8b0a MD |
1095 | The information available in the dynamic scopes can be thought of as the |
1096 | current tracing context. At trace production, information about the | |
1097 | current context is saved into the specified scope field levels. At trace | |
1098 | consumption, for each event, the current trace context is therefore | |
1099 | readable by accessing the upper dynamic scopes. | |
1100 | ||
fdf2bb05 | 1101 | |
6c7226e9 | 1102 | 7.4 TSDL Examples |
d285084f | 1103 | |
6672e9e1 | 1104 | The grammar representing the TSDL meta-data is presented in Appendix C. |
7df6b93a | 1105 | TSDL Grammar. This section presents a rather lighter reading that |
6672e9e1 | 1106 | consists in examples of TSDL meta-data, with template values. |
969f30c0 | 1107 | |
350bb633 MD |
1108 | The stream "id" can be left out if there is only one stream in the |
1109 | trace. The event "id" field can be left out if there is only one event | |
1110 | in a stream. | |
1111 | ||
5ba9f198 | 1112 | trace { |
fdf2bb05 | 1113 | major = value; /* Trace format version */ |
5ba9f198 | 1114 | minor = value; |
fdf2bb05 | 1115 | uuid = "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"; /* Trace UUID */ |
58997e9e | 1116 | byte_order = be OR le; /* Endianness (required) */ |
fc5425db MD |
1117 | packet.header := struct { |
1118 | uint32_t magic; | |
3fde5da1 | 1119 | uint8_t uuid[16]; |
fc5425db MD |
1120 | uint32_t stream_id; |
1121 | }; | |
3bf79539 | 1122 | }; |
5ba9f198 | 1123 | |
3bf79539 MD |
1124 | stream { |
1125 | id = stream_id; | |
fdf2bb05 | 1126 | /* Type 1 - Few event IDs; Type 2 - Many event IDs. See section 6.1. */ |
4fa992a5 MD |
1127 | event.header := event_header_1 OR event_header_2; |
1128 | event.context := struct { | |
77a98c82 | 1129 | ... |
3bf79539 | 1130 | }; |
4fa992a5 | 1131 | packet.context := struct { |
77a98c82 | 1132 | ... |
3bf79539 MD |
1133 | }; |
1134 | }; | |
5ba9f198 MD |
1135 | |
1136 | event { | |
980015f9 | 1137 | name = "event_name"; |
3bf79539 | 1138 | id = value; /* Numeric identifier within the stream */ |
67f02e24 | 1139 | stream_id = stream_id; |
980015f9 MD |
1140 | loglevel.identifier = "loglevel_identifier"; |
1141 | loglevel.value = value; | |
4fa992a5 | 1142 | context := struct { |
fcba70d4 MD |
1143 | ... |
1144 | }; | |
4fa992a5 | 1145 | fields := struct { |
80fd2569 MD |
1146 | ... |
1147 | }; | |
3bf79539 | 1148 | }; |
5ba9f198 MD |
1149 | |
1150 | /* More detail on types in section 4. Types */ | |
1151 | ||
3d13ef1a MD |
1152 | /* |
1153 | * Named types: | |
1154 | * | |
4fa992a5 | 1155 | * Type declarations behave similarly to the C standard. |
3d13ef1a MD |
1156 | */ |
1157 | ||
80af8ac6 | 1158 | typedef aliased_type_specifiers new_type_declarators; |
2152348f | 1159 | |
3d13ef1a | 1160 | /* e.g.: typedef struct example new_type_name[10]; */ |
80fd2569 | 1161 | |
4fa992a5 MD |
1162 | /* |
1163 | * typealias | |
1164 | * | |
1165 | * The "typealias" declaration can be used to give a name (including | |
80af8ac6 MD |
1166 | * pointer declarator specifier) to a type. It should also be used to |
1167 | * map basic C types (float, int, unsigned long, ...) to a CTF type. | |
1168 | * Typealias is a superset of "typedef": it also allows assignment of a | |
38b8da21 | 1169 | * simple variable identifier to a type. |
4fa992a5 MD |
1170 | */ |
1171 | ||
1172 | typealias type_class { | |
80fd2569 | 1173 | ... |
38b8da21 | 1174 | } := type_specifiers type_declarator; |
2152348f | 1175 | |
3d13ef1a MD |
1176 | /* |
1177 | * e.g.: | |
4fa992a5 | 1178 | * typealias integer { |
3d13ef1a MD |
1179 | * size = 32; |
1180 | * align = 32; | |
1181 | * signed = false; | |
38b8da21 | 1182 | * } := struct page *; |
359894ac MD |
1183 | * |
1184 | * typealias integer { | |
1185 | * size = 32; | |
1186 | * align = 32; | |
1187 | * signed = true; | |
38b8da21 | 1188 | * } := int; |
3d13ef1a | 1189 | */ |
80fd2569 MD |
1190 | |
1191 | struct name { | |
3bf79539 MD |
1192 | ... |
1193 | }; | |
5ba9f198 | 1194 | |
fcba70d4 MD |
1195 | variant name { |
1196 | ... | |
1197 | }; | |
1198 | ||
a9b83695 | 1199 | enum name : integer_type { |
3bf79539 MD |
1200 | ... |
1201 | }; | |
1202 | ||
2152348f | 1203 | |
4fa992a5 MD |
1204 | /* |
1205 | * Unnamed types, contained within compound type fields, typedef or typealias. | |
1206 | */ | |
2152348f | 1207 | |
80fd2569 MD |
1208 | struct { |
1209 | ... | |
2152348f | 1210 | } |
5ba9f198 | 1211 | |
ec4404a7 MD |
1212 | struct { |
1213 | ... | |
1214 | } align(value) | |
1215 | ||
fcba70d4 MD |
1216 | variant { |
1217 | ... | |
1218 | } | |
1219 | ||
a9b83695 | 1220 | enum : integer_type { |
80fd2569 | 1221 | ... |
2152348f MD |
1222 | } |
1223 | ||
1224 | typedef type new_type[length]; | |
3bf79539 | 1225 | |
2152348f MD |
1226 | struct { |
1227 | type field_name[length]; | |
1228 | } | |
1229 | ||
1230 | typedef type new_type[length_type]; | |
1231 | ||
1232 | struct { | |
1233 | type field_name[length_type]; | |
1234 | } | |
1235 | ||
1236 | integer { | |
80fd2569 | 1237 | ... |
2152348f | 1238 | } |
3bf79539 | 1239 | |
2152348f | 1240 | floating_point { |
80fd2569 | 1241 | ... |
2152348f MD |
1242 | } |
1243 | ||
1244 | struct { | |
1245 | integer_type field_name:size; /* GNU/C bitfield */ | |
1246 | } | |
1247 | ||
1248 | struct { | |
1249 | string field_name; | |
1250 | } | |
3bf79539 | 1251 | |
fcba70d4 | 1252 | |
2fa70eba MD |
1253 | 8. Clocks |
1254 | ||
1255 | Clock metadata allows to describe the clock topology of the system, as | |
1256 | well as to detail each clock parameter. In absence of clock description, | |
1257 | it is assumed that all fields named "timestamp" use the same clock | |
aed18b5e | 1258 | source, which increments once per nanosecond. |
2fa70eba MD |
1259 | |
1260 | Describing a clock and how it is used by streams is threefold: first, | |
1261 | the clock and clock topology should be described in a "clock" | |
1262 | description block, e.g.: | |
1263 | ||
d803bfcb | 1264 | clock { |
58262d97 | 1265 | name = cycle_counter_sync; |
2fa70eba | 1266 | uuid = "62189bee-96dc-11e0-91a8-cfa3d89f3923"; |
58262d97 | 1267 | description = "Cycle counter synchronized across CPUs"; |
2fa70eba MD |
1268 | freq = 1000000000; /* frequency, in Hz */ |
1269 | /* precision in seconds is: 1000 * (1/freq) */ | |
1270 | precision = 1000; | |
a40cccda MD |
1271 | /* |
1272 | * clock value offset from Epoch is: | |
1273 | * offset_s + (offset * (1/freq)) | |
1274 | */ | |
1275 | offset_s = 1326476837; | |
1276 | offset = 897235420; | |
ce0fadbd | 1277 | absolute = FALSE; |
2fa70eba MD |
1278 | }; |
1279 | ||
d803bfcb MD |
1280 | The mandatory "name" field specifies the name of the clock identifier, |
1281 | which can later be used as a reference. The optional field "uuid" is the | |
1282 | unique identifier of the clock. It can be used to correlate different | |
1283 | traces that use the same clock. An optional textual description string | |
1284 | can be added with the "description" field. The "freq" field is the | |
1285 | initial frequency of the clock, in Hz. If the "freq" field is not | |
1286 | present, the frequency is assumed to be 1000000000 (providing clock | |
1287 | increment of 1 ns). The optional "precision" field details the | |
a40cccda MD |
1288 | uncertainty on the clock measurements, in (1/freq) units. The "offset_s" |
1289 | and "offset" fields indicate the offset from POSIX.1 Epoch, 1970-01-01 | |
1290 | 00:00:00 +0000 (UTC), to the zero of value of the clock. The "offset_s" | |
1291 | field is in seconds. The "offset" field is in (1/freq) units. If any of | |
1292 | the "offset_s" or "offset" field is not present, it is assigned the 0 | |
ce0fadbd MD |
1293 | value. The field "absolute" is TRUE if the clock is a global reference |
1294 | across different clock uuid (e.g. NTP time). Otherwise, "absolute" is | |
1295 | FALSE, and the clock can be considered as synchronized only with other | |
1296 | clocks that have the same uuid. | |
1297 | ||
2fa70eba MD |
1298 | |
1299 | Secondly, a reference to this clock should be added within an integer | |
1300 | type: | |
1301 | ||
1302 | typealias integer { | |
1303 | size = 64; align = 1; signed = false; | |
58262d97 | 1304 | map = clock.cycle_counter_sync.value; |
2fa70eba MD |
1305 | } := uint64_ccnt_t; |
1306 | ||
1307 | Thirdly, stream declarations can reference the clock they use as a | |
1308 | time-stamp source: | |
1309 | ||
1310 | struct packet_context { | |
1311 | uint64_ccnt_t ccnt_begin; | |
1312 | uint64_ccnt_t ccnt_end; | |
1313 | /* ... */ | |
1314 | }; | |
1315 | ||
1316 | stream { | |
1317 | /* ... */ | |
1318 | event.header := struct { | |
1319 | uint64_ccnt_t timestamp; | |
1320 | /* ... */ | |
1321 | } | |
1322 | packet.context := struct packet_context; | |
1323 | }; | |
1324 | ||
1325 | For a N-bit integer type referring to a clock, if the integer overflows | |
1326 | compared to the N low order bits of the clock prior value, then it is | |
1327 | assumed that one, and only one, overflow occurred. It is therefore | |
1328 | important that events encoding time on a small number of bits happen | |
1329 | frequently enough to detect when more than one N-bit overflow occurs. | |
1330 | ||
1331 | In a packet context, clock field names ending with "_begin" and "_end" | |
1332 | have a special meaning: this refers to the time-stamps at, respectively, | |
1333 | the beginning and the end of each packet. | |
1334 | ||
1335 | ||
3bf79539 | 1336 | A. Helper macros |
5ba9f198 MD |
1337 | |
1338 | The two following macros keep track of the size of a GNU/C structure without | |
1339 | padding at the end by placing HEADER_END as the last field. A one byte end field | |
1340 | is used for C90 compatibility (C99 flexible arrays could be used here). Note | |
1341 | that this does not affect the effective structure size, which should always be | |
1342 | calculated with the header_sizeof() helper. | |
1343 | ||
1344 | #define HEADER_END char end_field | |
1345 | #define header_sizeof(type) offsetof(typeof(type), end_field) | |
3bf79539 MD |
1346 | |
1347 | ||
1348 | B. Stream Header Rationale | |
1349 | ||
1350 | An event stream is divided in contiguous event packets of variable size. These | |
1351 | subdivisions allow the trace analyzer to perform a fast binary search by time | |
1352 | within the stream (typically requiring to index only the event packet headers) | |
1353 | without reading the whole stream. These subdivisions have a variable size to | |
1354 | eliminate the need to transfer the event packet padding when partially filled | |
1355 | event packets must be sent when streaming a trace for live viewing/analysis. | |
1356 | An event packet can contain a certain amount of padding at the end. Dividing | |
1357 | streams into event packets is also useful for network streaming over UDP and | |
1358 | flight recorder mode tracing (a whole event packet can be swapped out of the | |
1359 | buffer atomically for reading). | |
1360 | ||
1361 | The stream header is repeated at the beginning of each event packet to allow | |
1362 | flexibility in terms of: | |
1363 | ||
1364 | - streaming support, | |
1365 | - allowing arbitrary buffers to be discarded without making the trace | |
1366 | unreadable, | |
1367 | - allow UDP packet loss handling by either dealing with missing event packet | |
1368 | or asking for re-transmission. | |
1369 | - transparently support flight recorder mode, | |
1370 | - transparently support crash dump. | |
1371 | ||
6c7226e9 MD |
1372 | |
1373 | C. TSDL Grammar | |
fcba70d4 | 1374 | |
4fa992a5 | 1375 | /* |
6c7226e9 | 1376 | * Common Trace Format (CTF) Trace Stream Description Language (TSDL) Grammar. |
4fa992a5 MD |
1377 | * |
1378 | * Inspired from the C99 grammar: | |
1379 | * http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf (Annex A) | |
6c7226e9 MD |
1380 | * and c++1x grammar (draft) |
1381 | * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3291.pdf (Annex A) | |
4fa992a5 MD |
1382 | * |
1383 | * Specialized for CTF needs by including only constant and declarations from | |
1384 | * C99 (excluding function declarations), and by adding support for variants, | |
6c7226e9 MD |
1385 | * sequences and CTF-specific specifiers. Enumeration container types |
1386 | * semantic is inspired from c++1x enum-base. | |
4fa992a5 MD |
1387 | */ |
1388 | ||
1389 | 1) Lexical grammar | |
1390 | ||
1391 | 1.1) Lexical elements | |
1392 | ||
1393 | token: | |
1394 | keyword | |
1395 | identifier | |
1396 | constant | |
1397 | string-literal | |
1398 | punctuator | |
1399 | ||
1400 | 1.2) Keywords | |
1401 | ||
1402 | keyword: is one of | |
1403 | ||
ec4404a7 | 1404 | align |
4fa992a5 MD |
1405 | const |
1406 | char | |
2fa70eba | 1407 | clock |
4fa992a5 MD |
1408 | double |
1409 | enum | |
1410 | event | |
1411 | floating_point | |
1412 | float | |
1413 | integer | |
1414 | int | |
1415 | long | |
1416 | short | |
1417 | signed | |
1418 | stream | |
1419 | string | |
1420 | struct | |
1421 | trace | |
3e1e1a78 | 1422 | typealias |
4fa992a5 MD |
1423 | typedef |
1424 | unsigned | |
1425 | variant | |
1426 | void | |
1427 | _Bool | |
1428 | _Complex | |
1429 | _Imaginary | |
1430 | ||
1431 | ||
1432 | 1.3) Identifiers | |
1433 | ||
1434 | identifier: | |
1435 | identifier-nondigit | |
1436 | identifier identifier-nondigit | |
1437 | identifier digit | |
1438 | ||
1439 | identifier-nondigit: | |
1440 | nondigit | |
1441 | universal-character-name | |
1442 | any other implementation-defined characters | |
1443 | ||
1444 | nondigit: | |
1445 | _ | |
1446 | [a-zA-Z] /* regular expression */ | |
1447 | ||
1448 | digit: | |
1449 | [0-9] /* regular expression */ | |
1450 | ||
1451 | 1.4) Universal character names | |
1452 | ||
1453 | universal-character-name: | |
1454 | \u hex-quad | |
1455 | \U hex-quad hex-quad | |
1456 | ||
1457 | hex-quad: | |
1458 | hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit | |
1459 | ||
1460 | 1.5) Constants | |
1461 | ||
1462 | constant: | |
1463 | integer-constant | |
1464 | enumeration-constant | |
1465 | character-constant | |
1466 | ||
1467 | integer-constant: | |
1468 | decimal-constant integer-suffix-opt | |
1469 | octal-constant integer-suffix-opt | |
1470 | hexadecimal-constant integer-suffix-opt | |
1471 | ||
1472 | decimal-constant: | |
1473 | nonzero-digit | |
1474 | decimal-constant digit | |
1475 | ||
1476 | octal-constant: | |
1477 | 0 | |
1478 | octal-constant octal-digit | |
1479 | ||
1480 | hexadecimal-constant: | |
1481 | hexadecimal-prefix hexadecimal-digit | |
1482 | hexadecimal-constant hexadecimal-digit | |
1483 | ||
1484 | hexadecimal-prefix: | |
1485 | 0x | |
1486 | 0X | |
1487 | ||
1488 | nonzero-digit: | |
1489 | [1-9] | |
1490 | ||
1491 | integer-suffix: | |
1492 | unsigned-suffix long-suffix-opt | |
1493 | unsigned-suffix long-long-suffix | |
1494 | long-suffix unsigned-suffix-opt | |
1495 | long-long-suffix unsigned-suffix-opt | |
1496 | ||
1497 | unsigned-suffix: | |
1498 | u | |
1499 | U | |
1500 | ||
1501 | long-suffix: | |
1502 | l | |
1503 | L | |
1504 | ||
1505 | long-long-suffix: | |
1506 | ll | |
1507 | LL | |
1508 | ||
4fa992a5 MD |
1509 | enumeration-constant: |
1510 | identifier | |
1511 | string-literal | |
1512 | ||
1513 | character-constant: | |
1514 | ' c-char-sequence ' | |
1515 | L' c-char-sequence ' | |
1516 | ||
1517 | c-char-sequence: | |
1518 | c-char | |
1519 | c-char-sequence c-char | |
1520 | ||
1521 | c-char: | |
1522 | any member of source charset except single-quote ('), backslash | |
1523 | (\), or new-line character. | |
1524 | escape-sequence | |
1525 | ||
1526 | escape-sequence: | |
1527 | simple-escape-sequence | |
1528 | octal-escape-sequence | |
1529 | hexadecimal-escape-sequence | |
1530 | universal-character-name | |
1531 | ||
1532 | simple-escape-sequence: one of | |
1533 | \' \" \? \\ \a \b \f \n \r \t \v | |
1534 | ||
1535 | octal-escape-sequence: | |
1536 | \ octal-digit | |
1537 | \ octal-digit octal-digit | |
1538 | \ octal-digit octal-digit octal-digit | |
1539 | ||
1540 | hexadecimal-escape-sequence: | |
1541 | \x hexadecimal-digit | |
1542 | hexadecimal-escape-sequence hexadecimal-digit | |
1543 | ||
1544 | 1.6) String literals | |
1545 | ||
1546 | string-literal: | |
1547 | " s-char-sequence-opt " | |
1548 | L" s-char-sequence-opt " | |
1549 | ||
1550 | s-char-sequence: | |
1551 | s-char | |
1552 | s-char-sequence s-char | |
1553 | ||
1554 | s-char: | |
1555 | any member of source charset except double-quote ("), backslash | |
1556 | (\), or new-line character. | |
1557 | escape-sequence | |
1558 | ||
1559 | 1.7) Punctuators | |
1560 | ||
1561 | punctuator: one of | |
1562 | [ ] ( ) { } . -> * + - < > : ; ... = , | |
1563 | ||
1564 | ||
1565 | 2) Phrase structure grammar | |
1566 | ||
1567 | primary-expression: | |
1568 | identifier | |
1569 | constant | |
1570 | string-literal | |
1571 | ( unary-expression ) | |
1572 | ||
1573 | postfix-expression: | |
1574 | primary-expression | |
1575 | postfix-expression [ unary-expression ] | |
1576 | postfix-expression . identifier | |
1577 | postfix-expressoin -> identifier | |
1578 | ||
1579 | unary-expression: | |
1580 | postfix-expression | |
1581 | unary-operator postfix-expression | |
1582 | ||
1583 | unary-operator: one of | |
1584 | + - | |
1585 | ||
4fa992a5 MD |
1586 | assignment-operator: |
1587 | = | |
1588 | ||
b9606a77 MD |
1589 | type-assignment-operator: |
1590 | := | |
1591 | ||
4fa992a5 | 1592 | constant-expression-range: |
73d61ac3 | 1593 | unary-expression ... unary-expression |
4fa992a5 MD |
1594 | |
1595 | 2.2) Declarations: | |
1596 | ||
1597 | declaration: | |
689e04b4 | 1598 | declaration-specifiers declarator-list-opt ; |
4fa992a5 MD |
1599 | ctf-specifier ; |
1600 | ||
1601 | declaration-specifiers: | |
689e04b4 | 1602 | storage-class-specifier declaration-specifiers-opt |
4fa992a5 MD |
1603 | type-specifier declaration-specifiers-opt |
1604 | type-qualifier declaration-specifiers-opt | |
1605 | ||
1606 | declarator-list: | |
1607 | declarator | |
1608 | declarator-list , declarator | |
1609 | ||
d285084f MD |
1610 | abstract-declarator-list: |
1611 | abstract-declarator | |
1612 | abstract-declarator-list , abstract-declarator | |
1613 | ||
4fa992a5 MD |
1614 | storage-class-specifier: |
1615 | typedef | |
1616 | ||
1617 | type-specifier: | |
1618 | void | |
1619 | char | |
1620 | short | |
1621 | int | |
1622 | long | |
1623 | float | |
1624 | double | |
1625 | signed | |
1626 | unsigned | |
1627 | _Bool | |
1628 | _Complex | |
cfdd51ec | 1629 | _Imaginary |
9dfcfc0f MD |
1630 | struct-specifier |
1631 | variant-specifier | |
4fa992a5 MD |
1632 | enum-specifier |
1633 | typedef-name | |
1634 | ctf-type-specifier | |
1635 | ||
ec4404a7 | 1636 | align-attribute: |
73d61ac3 | 1637 | align ( unary-expression ) |
ec4404a7 | 1638 | |
4fa992a5 | 1639 | struct-specifier: |
ec4404a7 MD |
1640 | struct identifier-opt { struct-or-variant-declaration-list-opt } align-attribute-opt |
1641 | struct identifier align-attribute-opt | |
4fa992a5 MD |
1642 | |
1643 | struct-or-variant-declaration-list: | |
1644 | struct-or-variant-declaration | |
1645 | struct-or-variant-declaration-list struct-or-variant-declaration | |
1646 | ||
1647 | struct-or-variant-declaration: | |
1648 | specifier-qualifier-list struct-or-variant-declarator-list ; | |
eacb16d1 | 1649 | declaration-specifiers-opt storage-class-specifier declaration-specifiers-opt declarator-list ; |
6143bab7 MD |
1650 | typealias declaration-specifiers abstract-declarator-list type-assignment-operator declaration-specifiers abstract-declarator-list ; |
1651 | typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list ; | |
4fa992a5 MD |
1652 | |
1653 | specifier-qualifier-list: | |
1654 | type-specifier specifier-qualifier-list-opt | |
1655 | type-qualifier specifier-qualifier-list-opt | |
1656 | ||
1657 | struct-or-variant-declarator-list: | |
1658 | struct-or-variant-declarator | |
1659 | struct-or-variant-declarator-list , struct-or-variant-declarator | |
1660 | ||
1661 | struct-or-variant-declarator: | |
1662 | declarator | |
73d61ac3 | 1663 | declarator-opt : unary-expression |
4fa992a5 MD |
1664 | |
1665 | variant-specifier: | |
1666 | variant identifier-opt variant-tag-opt { struct-or-variant-declaration-list } | |
1667 | variant identifier variant-tag | |
1668 | ||
1669 | variant-tag: | |
37ab95c3 | 1670 | < unary-expression > |
4fa992a5 MD |
1671 | |
1672 | enum-specifier: | |
1673 | enum identifier-opt { enumerator-list } | |
1674 | enum identifier-opt { enumerator-list , } | |
1675 | enum identifier | |
a9b83695 MD |
1676 | enum identifier-opt : declaration-specifiers { enumerator-list } |
1677 | enum identifier-opt : declaration-specifiers { enumerator-list , } | |
4fa992a5 MD |
1678 | |
1679 | enumerator-list: | |
1680 | enumerator | |
1681 | enumerator-list , enumerator | |
1682 | ||
1683 | enumerator: | |
1684 | enumeration-constant | |
8d2d41f7 MD |
1685 | enumeration-constant assignment-operator unary-expression |
1686 | enumeration-constant assignment-operator constant-expression-range | |
4fa992a5 MD |
1687 | |
1688 | type-qualifier: | |
1689 | const | |
1690 | ||
1691 | declarator: | |
1692 | pointer-opt direct-declarator | |
1693 | ||
1694 | direct-declarator: | |
1695 | identifier | |
1696 | ( declarator ) | |
1ab22b2a | 1697 | direct-declarator [ unary-expression ] |
4fa992a5 | 1698 | |
d285084f MD |
1699 | abstract-declarator: |
1700 | pointer-opt direct-abstract-declarator | |
1701 | ||
1702 | direct-abstract-declarator: | |
1703 | identifier-opt | |
1704 | ( abstract-declarator ) | |
1ab22b2a | 1705 | direct-abstract-declarator [ unary-expression ] |
d285084f MD |
1706 | direct-abstract-declarator [ ] |
1707 | ||
4fa992a5 | 1708 | pointer: |
3b0f8e4d MD |
1709 | * type-qualifier-list-opt |
1710 | * type-qualifier-list-opt pointer | |
4fa992a5 MD |
1711 | |
1712 | type-qualifier-list: | |
1713 | type-qualifier | |
1714 | type-qualifier-list type-qualifier | |
1715 | ||
4fa992a5 MD |
1716 | typedef-name: |
1717 | identifier | |
1718 | ||
1719 | 2.3) CTF-specific declarations | |
1720 | ||
1721 | ctf-specifier: | |
1722 | event { ctf-assignment-expression-list-opt } | |
1723 | stream { ctf-assignment-expression-list-opt } | |
1724 | trace { ctf-assignment-expression-list-opt } | |
b12919a5 MD |
1725 | typealias declaration-specifiers abstract-declarator-list type-assignment-operator declaration-specifiers abstract-declarator-list |
1726 | typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list | |
4fa992a5 MD |
1727 | |
1728 | ctf-type-specifier: | |
1729 | floating_point { ctf-assignment-expression-list-opt } | |
1730 | integer { ctf-assignment-expression-list-opt } | |
1731 | string { ctf-assignment-expression-list-opt } | |
7609d3c7 | 1732 | string |
4fa992a5 MD |
1733 | |
1734 | ctf-assignment-expression-list: | |
13441bf5 MD |
1735 | ctf-assignment-expression ; |
1736 | ctf-assignment-expression-list ctf-assignment-expression ; | |
4fa992a5 MD |
1737 | |
1738 | ctf-assignment-expression: | |
1739 | unary-expression assignment-operator unary-expression | |
1740 | unary-expression type-assignment-operator type-specifier | |
eacb16d1 | 1741 | declaration-specifiers-opt storage-class-specifier declaration-specifiers-opt declarator-list |
6143bab7 MD |
1742 | typealias declaration-specifiers abstract-declarator-list type-assignment-operator declaration-specifiers abstract-declarator-list |
1743 | typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list |