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5ba9f198 | 1 | |
4767a9e7 | 2 | RFC: Common Trace Format (CTF) Proposal (pre-v1.7) |
5ba9f198 MD |
3 | |
4 | Mathieu Desnoyers, EfficiOS Inc. | |
5 | ||
6 | The goal of the present document is to propose a trace format that suits the | |
cc089c3a | 7 | needs of the embedded, telecom, high-performance and kernel communities. It is |
5ba9f198 | 8 | based on the Common Trace Format Requirements (v1.4) document. It is designed to |
cc089c3a MD |
9 | allow traces to be natively generated by the Linux kernel, Linux user-space |
10 | applications written in C/C++, and hardware components. | |
11 | ||
12 | The latest version of this document can be found at: | |
13 | ||
14 | git tree: git://git.efficios.com/ctf.git | |
15 | gitweb: http://git.efficios.com/?p=ctf.git | |
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16 | |
17 | A reference implementation of a library to read and write this trace format is | |
18 | being implemented within the BabelTrace project, a converter between trace | |
19 | formats. The development tree is available at: | |
20 | ||
21 | git tree: git://git.efficios.com/babeltrace.git | |
22 | gitweb: http://git.efficios.com/?p=babeltrace.git | |
23 | ||
24 | ||
25 | 1. Preliminary definitions | |
26 | ||
3bf79539 MD |
27 | - Event Trace: An ordered sequence of events. |
28 | - Event Stream: An ordered sequence of events, containing a subset of the | |
29 | trace event types. | |
30 | - Event Packet: A sequence of physically contiguous events within an event | |
31 | stream. | |
5ba9f198 MD |
32 | - Event: This is the basic entry in a trace. (aka: a trace record). |
33 | - An event identifier (ID) relates to the class (a type) of event within | |
3bf79539 MD |
34 | an event stream. |
35 | e.g. event: irq_entry. | |
5ba9f198 MD |
36 | - An event (or event record) relates to a specific instance of an event |
37 | class. | |
3bf79539 MD |
38 | e.g. event: irq_entry, at time X, on CPU Y |
39 | - Source Architecture: Architecture writing the trace. | |
40 | - Reader Architecture: Architecture reading the trace. | |
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41 | |
42 | ||
43 | 2. High-level representation of a trace | |
44 | ||
3bf79539 MD |
45 | A trace is divided into multiple event streams. Each event stream contains a |
46 | subset of the trace event types. | |
5ba9f198 | 47 | |
3bf79539 MD |
48 | The final output of the trace, after its generation and optional transport over |
49 | the network, is expected to be either on permanent or temporary storage in a | |
50 | virtual file system. Because each event stream is appended to while a trace is | |
51 | being recorded, each is associated with a separate file for output. Therefore, | |
52 | a stored trace can be represented as a directory containing one file per stream. | |
5ba9f198 | 53 | |
3bf79539 | 54 | A metadata event stream contains information on trace event types. It describes: |
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55 | |
56 | - Trace version. | |
57 | - Types available. | |
3bf79539 MD |
58 | - Per-stream event header description. |
59 | - Per-stream event header selection. | |
60 | - Per-stream event context fields. | |
5ba9f198 | 61 | - Per-event |
3bf79539 | 62 | - Event type to stream mapping. |
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63 | - Event type to name mapping. |
64 | - Event type to ID mapping. | |
65 | - Event fields description. | |
66 | ||
67 | ||
3bf79539 | 68 | 3. Event stream |
5ba9f198 | 69 | |
3bf79539 MD |
70 | An event stream is divided in contiguous event packets of variable size. These |
71 | subdivisions have a variable size. An event packet can contain a certain amount | |
72 | of padding at the end. The rationale for the event stream design choices is | |
73 | explained in Appendix B. Stream Header Rationale. | |
5ba9f198 | 74 | |
3bf79539 MD |
75 | An event stream is divided in contiguous event packets of variable size. These |
76 | subdivisions have a variable size. An event packet can contain a certain amount | |
77 | of padding at the end. The stream header is repeated at the beginning of each | |
78 | event packet. | |
5ba9f198 | 79 | |
3bf79539 MD |
80 | The event stream header will therefore be referred to as the "event packet |
81 | header" throughout the rest of this document. | |
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82 | |
83 | ||
84 | 4. Types | |
85 | ||
86 | 4.1 Basic types | |
87 | ||
88 | A basic type is a scalar type, as described in this section. | |
89 | ||
90 | 4.1.1 Type inheritance | |
91 | ||
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92 | Type specifications can be inherited to allow deriving types from a |
93 | type class. For example, see the uint32_t named type derived from the "integer" | |
94 | type class below ("Integers" section). Types have a precise binary | |
95 | representation in the trace. A type class has methods to read and write these | |
96 | types, but must be derived into a type to be usable in an event field. | |
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97 | |
98 | 4.1.2 Alignment | |
99 | ||
100 | We define "byte-packed" types as aligned on the byte size, namely 8-bit. | |
101 | We define "bit-packed" types as following on the next bit, as defined by the | |
102 | "bitfields" section. | |
5ba9f198 | 103 | |
3bf79539 MD |
104 | All basic types, except bitfields, are either aligned on an architecture-defined |
105 | specific alignment or byte-packed, depending on the architecture preference. | |
106 | Architectures providing fast unaligned write byte-packed basic types to save | |
5ba9f198 | 107 | space, aligning each type on byte boundaries (8-bit). Architectures with slow |
3bf79539 MD |
108 | unaligned writes align types on specific alignment values. If no specific |
109 | alignment is declared for a type nor its parents, it is assumed to be bit-packed | |
110 | for bitfields and byte-packed for other types. | |
5ba9f198 | 111 | |
3bf79539 | 112 | Metadata attribute representation of a specific alignment: |
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113 | |
114 | align = value; /* value in bits */ | |
115 | ||
116 | 4.1.3 Byte order | |
117 | ||
3bf79539 MD |
118 | By default, the native endianness of the source architecture the trace is used. |
119 | Byte order can be overridden for a basic type by specifying a "byte_order" | |
120 | attribute. Typical use-case is to specify the network byte order (big endian: | |
121 | "be") to save data captured from the network into the trace without conversion. | |
122 | If not specified, the byte order is native. | |
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123 | |
124 | Metadata representation: | |
125 | ||
126 | byte_order = native OR network OR be OR le; /* network and be are aliases */ | |
127 | ||
128 | 4.1.4 Size | |
129 | ||
130 | Type size, in bits, for integers and floats is that returned by "sizeof()" in C | |
131 | multiplied by CHAR_BIT. | |
132 | We require the size of "char" and "unsigned char" types (CHAR_BIT) to be fixed | |
133 | to 8 bits for cross-endianness compatibility. | |
134 | ||
135 | Metadata representation: | |
136 | ||
137 | size = value; (value is in bits) | |
138 | ||
139 | 4.1.5 Integers | |
140 | ||
141 | Signed integers are represented in two-complement. Integer alignment, size, | |
142 | signedness and byte ordering are defined in the metadata. Integers aligned on | |
143 | byte size (8-bit) and with length multiple of byte size (8-bit) correspond to | |
144 | the C99 standard integers. In addition, integers with alignment and/or size that | |
145 | are _not_ a multiple of the byte size are permitted; these correspond to the C99 | |
146 | standard bitfields, with the added specification that the CTF integer bitfields | |
147 | have a fixed binary representation. A MIT-licensed reference implementation of | |
148 | the CTF portable bitfields is available at: | |
149 | ||
150 | http://git.efficios.com/?p=babeltrace.git;a=blob;f=include/babeltrace/bitfield.h | |
151 | ||
152 | Binary representation of integers: | |
153 | ||
154 | - On little and big endian: | |
155 | - Within a byte, high bits correspond to an integer high bits, and low bits | |
156 | correspond to low bits. | |
157 | - On little endian: | |
158 | - Integer across multiple bytes are placed from the less significant to the | |
159 | most significant. | |
160 | - Consecutive integers are placed from lower bits to higher bits (even within | |
161 | a byte). | |
162 | - On big endian: | |
163 | - Integer across multiple bytes are placed from the most significant to the | |
164 | less significant. | |
165 | - Consecutive integers are placed from higher bits to lower bits (even within | |
166 | a byte). | |
167 | ||
168 | This binary representation is derived from the bitfield implementation in GCC | |
169 | for little and big endian. However, contrary to what GCC does, integers can | |
170 | cross units boundaries (no padding is required). Padding can be explicitely | |
171 | added (see 4.1.6 GNU/C bitfields) to follow the GCC layout if needed. | |
172 | ||
173 | Metadata representation: | |
174 | ||
80fd2569 | 175 | integer { |
5ba9f198 MD |
176 | signed = true OR false; /* default false */ |
177 | byte_order = native OR network OR be OR le; /* default native */ | |
178 | size = value; /* value in bits, no default */ | |
179 | align = value; /* value in bits */ | |
2152348f | 180 | } |
5ba9f198 | 181 | |
80fd2569 | 182 | Example of type inheritance (creation of a uint32_t named type): |
5ba9f198 | 183 | |
80fd2569 | 184 | typedef integer { |
9e4e34e9 | 185 | size = 32; |
5ba9f198 MD |
186 | signed = false; |
187 | align = 32; | |
80fd2569 | 188 | } uint32_t; |
5ba9f198 | 189 | |
80fd2569 | 190 | Definition of a named 5-bit signed bitfield: |
5ba9f198 | 191 | |
80fd2569 | 192 | typedef integer { |
5ba9f198 MD |
193 | size = 5; |
194 | signed = true; | |
195 | align = 1; | |
80fd2569 | 196 | } int5_t; |
5ba9f198 MD |
197 | |
198 | 4.1.6 GNU/C bitfields | |
199 | ||
200 | The GNU/C bitfields follow closely the integer representation, with a | |
201 | particularity on alignment: if a bitfield cannot fit in the current unit, the | |
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202 | unit is padded and the bitfield starts at the following unit. The unit size is |
203 | defined by the size of the type "unit_type". | |
5ba9f198 | 204 | |
2152348f | 205 | Metadata representation: |
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206 | |
207 | unit_type name:size: | |
208 | ||
5ba9f198 MD |
209 | As an example, the following structure declared in C compiled by GCC: |
210 | ||
211 | struct example { | |
212 | short a:12; | |
213 | short b:5; | |
214 | }; | |
215 | ||
2152348f MD |
216 | The example structure is aligned on the largest element (short). The second |
217 | bitfield would be aligned on the next unit boundary, because it would not fit in | |
218 | the current unit. | |
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219 | |
220 | 4.1.7 Floating point | |
221 | ||
222 | The floating point values byte ordering is defined in the metadata. | |
223 | ||
224 | Floating point values follow the IEEE 754-2008 standard interchange formats. | |
225 | Description of the floating point values include the exponent and mantissa size | |
226 | in bits. Some requirements are imposed on the floating point values: | |
227 | ||
228 | - FLT_RADIX must be 2. | |
229 | - mant_dig is the number of digits represented in the mantissa. It is specified | |
230 | by the ISO C99 standard, section 5.2.4, as FLT_MANT_DIG, DBL_MANT_DIG and | |
231 | LDBL_MANT_DIG as defined by <float.h>. | |
232 | - exp_dig is the number of digits represented in the exponent. Given that | |
233 | mant_dig is one bit more than its actual size in bits (leading 1 is not | |
234 | needed) and also given that the sign bit always takes one bit, exp_dig can be | |
235 | specified as: | |
236 | ||
237 | - sizeof(float) * CHAR_BIT - FLT_MANT_DIG | |
238 | - sizeof(double) * CHAR_BIT - DBL_MANT_DIG | |
239 | - sizeof(long double) * CHAR_BIT - LDBL_MANT_DIG | |
240 | ||
241 | Metadata representation: | |
242 | ||
80fd2569 | 243 | floating_point { |
5ba9f198 MD |
244 | exp_dig = value; |
245 | mant_dig = value; | |
246 | byte_order = native OR network OR be OR le; | |
2152348f | 247 | } |
5ba9f198 MD |
248 | |
249 | Example of type inheritance: | |
250 | ||
80fd2569 | 251 | typedef floating_point { |
5ba9f198 MD |
252 | exp_dig = 8; /* sizeof(float) * CHAR_BIT - FLT_MANT_DIG */ |
253 | mant_dig = 24; /* FLT_MANT_DIG */ | |
254 | byte_order = native; | |
80fd2569 | 255 | } float; |
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256 | |
257 | TODO: define NaN, +inf, -inf behavior. | |
258 | ||
259 | 4.1.8 Enumerations | |
260 | ||
261 | Enumerations are a mapping between an integer type and a table of strings. The | |
262 | numerical representation of the enumeration follows the integer type specified | |
263 | by the metadata. The enumeration mapping table is detailed in the enumeration | |
3bf79539 MD |
264 | description within the metadata. The mapping table maps inclusive value ranges |
265 | (or single values) to strings. Instead of being limited to simple | |
266 | "value -> string" mappings, these enumerations map | |
80fd2569 | 267 | "[ start_value ... end_value ] -> string", which map inclusive ranges of |
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268 | values to strings. An enumeration from the C language can be represented in |
269 | this format by having the same start_value and end_value for each element, which | |
270 | is in fact a range of size 1. This single-value range is supported without | |
4767a9e7 | 271 | repeating the start and end values with the value = string declaration. |
80fd2569 | 272 | |
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273 | If a numeric value is encountered between < >, it represents the integer type |
274 | size used to hold the enumeration, in bits. | |
275 | ||
cfc73fdc | 276 | enum name <integer_type OR size> { |
80fd2569 MD |
277 | string = start_value1 ... end_value1, |
278 | "other string" = start_value2 ... end_value2, | |
279 | yet_another_string, /* will be assigned to end_value2 + 1 */ | |
280 | "some other string" = value, | |
281 | ... | |
282 | }; | |
283 | ||
284 | If the values are omitted, the enumeration starts at 0 and increment of 1 for | |
285 | each entry: | |
286 | ||
cfc73fdc | 287 | enum name <32> { |
80fd2569 MD |
288 | ZERO, |
289 | ONE, | |
290 | TWO, | |
291 | TEN = 10, | |
292 | ELEVEN, | |
3bf79539 | 293 | }; |
5ba9f198 | 294 | |
80fd2569 | 295 | Overlapping ranges within a single enumeration are implementation defined. |
5ba9f198 | 296 | |
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297 | A nameless enumeration can be declared as a field type or as part of a typedef: |
298 | ||
299 | enum <integer_type> { | |
300 | ... | |
301 | } | |
302 | ||
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303 | 4.2 Compound types |
304 | ||
305 | 4.2.1 Structures | |
306 | ||
307 | Structures are aligned on the largest alignment required by basic types | |
308 | contained within the structure. (This follows the ISO/C standard for structures) | |
309 | ||
80fd2569 | 310 | Metadata representation of a named structure: |
5ba9f198 | 311 | |
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312 | struct name { |
313 | field_type field_name; | |
314 | field_type field_name; | |
315 | ... | |
316 | }; | |
5ba9f198 MD |
317 | |
318 | Example: | |
319 | ||
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320 | struct example { |
321 | integer { /* Nameless type */ | |
322 | size = 16; | |
323 | signed = true; | |
324 | align = 16; | |
325 | } first_field_name; | |
326 | uint64_t second_field_name; /* Named type declared in the metadata */ | |
3bf79539 | 327 | }; |
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328 | |
329 | The fields are placed in a sequence next to each other. They each possess a | |
330 | field name, which is a unique identifier within the structure. | |
331 | ||
2152348f | 332 | A nameless structure can be declared as a field type or as part of a typedef: |
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333 | |
334 | struct { | |
335 | ... | |
2152348f | 336 | } |
80fd2569 | 337 | |
77a98c82 | 338 | 4.2.2 Variants (Discriminated/Tagged Unions) |
fcba70d4 MD |
339 | |
340 | A CTF variant is a selection between different types. A CTF variant must always | |
341 | be defined within the scope of a structure or within fields contained within a | |
342 | structure (defined recursively). A "tag" enumeration field must appear in either | |
343 | the same lexical scope or an uppermost scope, prior to the variant field (in | |
344 | field declaration order). The type selection is indicated by the mapping from | |
345 | the enumeration value to the string used as variant type selector. The field to | |
346 | use as tag is specified by the "tag_field", specified between "< >" after the | |
347 | "variant" keyword for unnamed variants, and after "variant name" for named | |
348 | variants. | |
349 | ||
350 | The alignment of the variant is the alignment of the type as selected by the tag | |
351 | value for the specific instance of the variant. The alignment of the type | |
352 | containing the variant is independent of the variant alignment. The size of the | |
353 | variant is the size as selected by the tag value for the specific instance of | |
354 | the variant. | |
355 | ||
356 | A named variant declaration followed by its definition within a structure | |
357 | declaration: | |
358 | ||
359 | variant name { | |
360 | field_type sel1; | |
361 | field_type sel2; | |
362 | field_type sel3; | |
363 | ... | |
364 | }; | |
365 | ||
366 | struct { | |
367 | enum <integer_type or size> { sel1, sel2, sel3, ... } tag_field; | |
368 | ... | |
369 | variant name <tag_field> v; | |
370 | } | |
371 | ||
372 | An unnamed variant definition within a structure is expressed by the following | |
373 | metadata: | |
374 | ||
375 | struct { | |
376 | enum <integer_type or size> { sel1, sel2, sel3, ... } tag_field; | |
377 | ... | |
378 | variant <tag_field> { | |
379 | field_type sel1; | |
380 | field_type sel2; | |
381 | field_type sel3; | |
382 | ... | |
383 | } v; | |
384 | } | |
385 | ||
386 | Example of a named variant within a sequence that refers to a single tag field: | |
387 | ||
388 | variant example { | |
389 | uint32_t a; | |
390 | uint64_t b; | |
391 | short c; | |
392 | }; | |
393 | ||
394 | struct { | |
395 | enum <uint2_t> { a, b, c } choice; | |
15850440 | 396 | variant example <choice> v[unsigned int]; |
fcba70d4 MD |
397 | } |
398 | ||
399 | Example of an unnamed variant: | |
400 | ||
401 | struct { | |
402 | enum <uint2_t> { a, b, c, d } choice; | |
403 | /* Unrelated fields can be added between the variant and its tag */ | |
404 | int32_t somevalue; | |
405 | variant <choice> { | |
406 | uint32_t a; | |
407 | uint64_t b; | |
408 | short c; | |
409 | struct { | |
410 | unsigned int field1; | |
411 | uint64_t field2; | |
412 | } d; | |
413 | } s; | |
414 | } | |
415 | ||
416 | Example of an unnamed variant within an array: | |
417 | ||
418 | struct { | |
419 | enum <uint2_t> { a, b, c } choice; | |
420 | variant <choice> { | |
421 | uint32_t a; | |
422 | uint64_t b; | |
423 | short c; | |
15850440 | 424 | } v[10]; |
fcba70d4 MD |
425 | } |
426 | ||
427 | Example of a variant type definition within a structure, where the defined type | |
428 | is then declared within an array of structures. This variant refers to a tag | |
429 | located in an upper lexical scope. This example clearly shows that a variant | |
430 | type definition referring to the tag "x" uses the closest preceding field from | |
431 | the lexical scope of the type definition. | |
432 | ||
433 | struct { | |
434 | enum <uint2_t> { a, b, c, d } x; | |
435 | ||
436 | typedef variant <x> { /* | |
437 | * "x" refers to the preceding "x" enumeration in the | |
438 | * lexical scope of the type definition. | |
439 | */ | |
440 | uint32_t a; | |
441 | uint64_t b; | |
442 | short c; | |
443 | } example_variant; | |
444 | ||
445 | struct { | |
446 | enum <int> { x, y, z } x; /* This enumeration is not used by "v". */ | |
447 | example_variant v; /* | |
448 | * "v" uses the "enum <uint2_t> { a, b, c, d }" | |
449 | * tag. | |
450 | */ | |
451 | } a[10]; | |
452 | } | |
453 | ||
454 | 4.2.3 Arrays | |
5ba9f198 MD |
455 | |
456 | Arrays are fixed-length. Their length is declared in the type declaration within | |
457 | the metadata. They contain an array of "inner type" elements, which can refer to | |
458 | any type not containing the type of the array being declared (no circular | |
3bf79539 | 459 | dependency). The length is the number of elements in an array. |
5ba9f198 | 460 | |
2152348f | 461 | Metadata representation of a named array: |
80fd2569 MD |
462 | |
463 | typedef elem_type name[length]; | |
5ba9f198 | 464 | |
2152348f | 465 | A nameless array can be declared as a field type within a structure, e.g.: |
5ba9f198 | 466 | |
2152348f | 467 | uint8_t field_name[10]; |
80fd2569 | 468 | |
5ba9f198 | 469 | |
fcba70d4 | 470 | 4.2.4 Sequences |
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471 | |
472 | Sequences are dynamically-sized arrays. They start with an integer that specify | |
473 | the length of the sequence, followed by an array of "inner type" elements. | |
3bf79539 | 474 | The length is the number of elements in the sequence. |
5ba9f198 | 475 | |
2152348f | 476 | Metadata representation for a named sequence: |
80fd2569 MD |
477 | |
478 | typedef elem_type name[length_type]; | |
479 | ||
480 | A nameless sequence can be declared as a field type, e.g.: | |
481 | ||
80fd2569 MD |
482 | long field_name[int]; |
483 | ||
484 | The length type follows the integer types specifications, and the sequence | |
5ba9f198 MD |
485 | elements follow the "array" specifications. |
486 | ||
fcba70d4 | 487 | 4.2.5 Strings |
5ba9f198 MD |
488 | |
489 | Strings are an array of bytes of variable size and are terminated by a '\0' | |
490 | "NULL" character. Their encoding is described in the metadata. In absence of | |
491 | encoding attribute information, the default encoding is UTF-8. | |
492 | ||
80fd2569 MD |
493 | Metadata representation of a named string type: |
494 | ||
495 | typedef string { | |
5ba9f198 | 496 | encoding = UTF8 OR ASCII; |
80fd2569 | 497 | } name; |
5ba9f198 | 498 | |
80fd2569 MD |
499 | A nameless string type can be declared as a field type: |
500 | ||
501 | string field_name; /* Use default UTF8 encoding */ | |
5ba9f198 | 502 | |
3bf79539 MD |
503 | 5. Event Packet Header |
504 | ||
505 | The event packet header consists of two part: one is mandatory and have a fixed | |
506 | layout. The second part, the "event packet context", has its layout described in | |
507 | the metadata. | |
5ba9f198 | 508 | |
3bf79539 MD |
509 | - Aligned on page size. Fixed size. Fields either aligned or packed (depending |
510 | on the architecture preference). | |
511 | No padding at the end of the event packet header. Native architecture byte | |
5ba9f198 | 512 | ordering. |
3bf79539 MD |
513 | |
514 | Fixed layout (event packet header): | |
515 | ||
5ba9f198 MD |
516 | - Magic number (CTF magic numbers: 0xC1FC1FC1 and its reverse endianness |
517 | representation: 0xC11FFCC1) It needs to have a non-symmetric bytewise | |
518 | representation. Used to distinguish between big and little endian traces (this | |
519 | information is determined by knowing the endianness of the architecture | |
520 | reading the trace and comparing the magic number against its value and the | |
521 | reverse, 0xC11FFCC1). This magic number specifies that we use the CTF metadata | |
522 | description language described in this document. Different magic numbers | |
523 | should be used for other metadata description languages. | |
3bf79539 | 524 | - Trace UUID, used to ensure the event packet match the metadata used. |
5ba9f198 MD |
525 | (note: we cannot use a metadata checksum because metadata can be appended to |
526 | while tracing is active) | |
3bf79539 MD |
527 | - Stream ID, used as reference to stream description in metadata. |
528 | ||
529 | Metadata-defined layout (event packet context): | |
530 | ||
531 | - Event packet content size (in bytes). | |
532 | - Event packet size (in bytes, includes padding). | |
533 | - Event packet content checksum (optional). Checksum excludes the event packet | |
534 | header. | |
535 | - Per-stream event packet sequence count (to deal with UDP packet loss). The | |
536 | number of significant sequence counter bits should also be present, so | |
537 | wrap-arounds are deal with correctly. | |
538 | - Timestamp at the beginning and timestamp at the end of the event packet. | |
539 | Both timestamps are written in the packet header, but sampled respectively | |
540 | while (or before) writing the first event and while (or after) writing the | |
541 | last event in the packet. The inclusive range between these timestamps should | |
542 | include all event timestamps assigned to events contained within the packet. | |
5ba9f198 | 543 | - Events discarded count |
3bf79539 MD |
544 | - Snapshot of a per-stream free-running counter, counting the number of |
545 | events discarded that were supposed to be written in the stream prior to | |
546 | the first event in the event packet. | |
5ba9f198 | 547 | * Note: producer-consumer buffer full condition should fill the current |
3bf79539 | 548 | event packet with padding so we know exactly where events have been |
5ba9f198 | 549 | discarded. |
3bf79539 MD |
550 | - Lossless compression scheme used for the event packet content. Applied |
551 | directly to raw data. New types of compression can be added in following | |
552 | versions of the format. | |
5ba9f198 MD |
553 | 0: no compression scheme |
554 | 1: bzip2 | |
555 | 2: gzip | |
3bf79539 MD |
556 | 3: xz |
557 | - Cypher used for the event packet content. Applied after compression. | |
5ba9f198 MD |
558 | 0: no encryption |
559 | 1: AES | |
3bf79539 | 560 | - Checksum scheme used for the event packet content. Applied after encryption. |
5ba9f198 MD |
561 | 0: no checksum |
562 | 1: md5 | |
563 | 2: sha1 | |
564 | 3: crc32 | |
565 | ||
3bf79539 MD |
566 | 5.1 Event Packet Header Fixed Layout Description |
567 | ||
80fd2569 MD |
568 | struct event_packet_header { |
569 | uint32_t magic; | |
570 | uint8_t trace_uuid[16]; | |
3bf79539 | 571 | uint32_t stream_id; |
80fd2569 | 572 | }; |
5ba9f198 | 573 | |
3bf79539 MD |
574 | 5.2 Event Packet Context Description |
575 | ||
576 | Event packet context example. These are declared within the stream declaration | |
577 | in the metadata. All these fields are optional except for "content_size" and | |
578 | "packet_size", which must be present in the context. | |
579 | ||
580 | An example event packet context type: | |
581 | ||
80fd2569 | 582 | struct event_packet_context { |
3bf79539 MD |
583 | uint64_t timestamp_begin; |
584 | uint64_t timestamp_end; | |
585 | uint32_t checksum; | |
586 | uint32_t stream_packet_count; | |
587 | uint32_t events_discarded; | |
588 | uint32_t cpu_id; | |
589 | uint32_t/uint16_t content_size; | |
590 | uint32_t/uint16_t packet_size; | |
591 | uint8_t stream_packet_count_bits; /* Significant counter bits */ | |
592 | uint8_t compression_scheme; | |
593 | uint8_t encryption_scheme; | |
594 | uint8_t checksum; | |
595 | }; | |
5ba9f198 | 596 | |
fcba70d4 | 597 | |
5ba9f198 MD |
598 | 6. Event Structure |
599 | ||
600 | The overall structure of an event is: | |
601 | ||
fcba70d4 MD |
602 | 1 - Stream Packet Context (as specified by the stream metadata) |
603 | 2 - Event Header (as specifed by the stream metadata) | |
604 | 3 - Stream Event Context (as specified by the stream metadata) | |
605 | 4 - Event Context (as specified by the event metadata) | |
606 | 5 - Event Payload (as specified by the event metadata) | |
5ba9f198 | 607 | |
fcba70d4 | 608 | 6.1 Lexical Scope |
5ba9f198 | 609 | |
fcba70d4 MD |
610 | The lexical scope of each structure (stream packet context, header, stream event |
611 | context, event context and payload) is extended in the following way: lower | |
612 | levels (e.g. 3) can refer to fields defined in prior levels (e.g. 2 and 1). The | |
613 | field in the closest level has priority in case of field name conflict. | |
614 | ||
615 | This allows, for instance, the event context to define a variant refering to the | |
616 | "id" field of the event header as selector. | |
617 | ||
618 | 6.2 Event Header | |
619 | ||
620 | Event headers can be described within the metadata. We hereby propose, as an | |
621 | example, two types of events headers. Type 1 accommodates streams with less than | |
622 | 31 event IDs. Type 2 accommodates streams with 31 or more event IDs. | |
5ba9f198 | 623 | |
3bf79539 MD |
624 | One major factor can vary between streams: the number of event IDs assigned to |
625 | a stream. Luckily, this information tends to stay relatively constant (modulo | |
5ba9f198 | 626 | event registration while trace is being recorded), so we can specify different |
3bf79539 | 627 | representations for streams containing few event IDs and streams containing |
5ba9f198 MD |
628 | many event IDs, so we end up representing the event ID and timestamp as densely |
629 | as possible in each case. | |
630 | ||
fcba70d4 MD |
631 | The header is extended in the rare occasions where the information cannot be |
632 | represented in the ranges available in the standard event header. They are also | |
3bf79539 MD |
633 | used in the rare occasions where the data required for a field could not be |
634 | collected: the flag corresponding to the missing field within the missing_fields | |
635 | array is then set to 1. | |
5ba9f198 MD |
636 | |
637 | Types uintX_t represent an X-bit unsigned integer. | |
638 | ||
639 | ||
fcba70d4 | 640 | 6.2.1 Type 1 - Few event IDs |
5ba9f198 MD |
641 | |
642 | - Aligned on 32-bit (or 8-bit if byte-packed, depending on the architecture | |
643 | preference). | |
5ba9f198 | 644 | - Native architecture byte ordering. |
fcba70d4 MD |
645 | - For "compact" selection |
646 | - Fixed size: 32 bits. | |
647 | - For "extended" selection | |
648 | - Size depends on the architecture and variant alignment. | |
5ba9f198 | 649 | |
80fd2569 | 650 | struct event_header_1 { |
fcba70d4 MD |
651 | /* |
652 | * id: range: 0 - 30. | |
653 | * id 31 is reserved to indicate an extended header. | |
654 | */ | |
655 | enum <uint5_t> { compact = 0 ... 30, extended = 31 } id; | |
656 | variant <id> { | |
657 | struct { | |
658 | uint27_t timestamp; | |
659 | } compact; | |
660 | struct { | |
661 | uint32_t id; /* 32-bit event IDs */ | |
662 | uint64_t timestamp; /* 64-bit timestamps */ | |
663 | } extended; | |
664 | } v; | |
5ba9f198 MD |
665 | }; |
666 | ||
5ba9f198 | 667 | |
fcba70d4 | 668 | 6.2.2 Type 2 - Many event IDs |
5ba9f198 | 669 | |
fcba70d4 | 670 | - Aligned on 16-bit (or 8-bit if byte-packed, depending on the architecture |
5ba9f198 | 671 | preference). |
5ba9f198 | 672 | - Native architecture byte ordering. |
fcba70d4 MD |
673 | - For "compact" selection |
674 | - Size depends on the architecture and variant alignment. | |
675 | - For "extended" selection | |
676 | - Size depends on the architecture and variant alignment. | |
5ba9f198 | 677 | |
80fd2569 | 678 | struct event_header_2 { |
fcba70d4 MD |
679 | /* |
680 | * id: range: 0 - 65534. | |
681 | * id 65535 is reserved to indicate an extended header. | |
682 | */ | |
683 | enum <uint16_t> { compact = 0 ... 65534, extended = 65535 } id; | |
684 | variant <id> { | |
685 | struct { | |
686 | uint32_t timestamp; | |
687 | } compact; | |
688 | struct { | |
689 | uint32_t id; /* 32-bit event IDs */ | |
690 | uint64_t timestamp; /* 64-bit timestamps */ | |
691 | } extended; | |
692 | } v; | |
5ba9f198 MD |
693 | }; |
694 | ||
5ba9f198 MD |
695 | |
696 | 6.2 Event Context | |
697 | ||
698 | The event context contains information relative to the current event. The choice | |
fcba70d4 MD |
699 | and meaning of this information is specified by the metadata "stream" and |
700 | "event" information. The "stream" context is applied to all events within the | |
701 | stream. The "stream" context structure follows the event header. The "event" | |
702 | context is applied to specific events. Its structure follows the "stream" | |
703 | context stucture. | |
5ba9f198 | 704 | |
fcba70d4 MD |
705 | An example of stream-level event context is to save the event payload size with |
706 | each event, or to save the current PID with each event. These are declared | |
707 | within the stream declaration within the metadata: | |
5ba9f198 | 708 | |
fcba70d4 MD |
709 | stream { |
710 | ... | |
711 | event { | |
712 | ... | |
4fa992a5 | 713 | context := struct { |
80fd2569 MD |
714 | uint pid; |
715 | uint16_t payload_size; | |
3bf79539 | 716 | }; |
fcba70d4 MD |
717 | } |
718 | }; | |
719 | ||
720 | An example of event-specific event context is to declare a bitmap of missing | |
721 | fields, only appended after the stream event context if the extended event | |
722 | header is selected. NR_FIELDS is the number of fields within the event (a | |
723 | numeric value). | |
5ba9f198 | 724 | |
fcba70d4 MD |
725 | event { |
726 | context = struct { | |
727 | variant <id> { | |
728 | struct { } compact; | |
729 | struct { | |
730 | uint1_t missing_fields[NR_FIELDS]; /* missing event fields bitmap */ | |
731 | } extended; | |
732 | } v; | |
733 | }; | |
734 | ... | |
735 | } | |
5ba9f198 MD |
736 | |
737 | 6.3 Event Payload | |
738 | ||
739 | An event payload contains fields specific to a given event type. The fields | |
740 | belonging to an event type are described in the event-specific metadata | |
741 | within a structure type. | |
742 | ||
743 | 6.3.1 Padding | |
744 | ||
745 | No padding at the end of the event payload. This differs from the ISO/C standard | |
746 | for structures, but follows the CTF standard for structures. In a trace, even | |
747 | though it makes sense to align the beginning of a structure, it really makes no | |
748 | sense to add padding at the end of the structure, because structures are usually | |
749 | not followed by a structure of the same type. | |
750 | ||
751 | This trick can be done by adding a zero-length "end" field at the end of the C | |
752 | structures, and by using the offset of this field rather than using sizeof() | |
3bf79539 | 753 | when calculating the size of a structure (see Appendix "A. Helper macros"). |
5ba9f198 MD |
754 | |
755 | 6.3.2 Alignment | |
756 | ||
757 | The event payload is aligned on the largest alignment required by types | |
758 | contained within the payload. (This follows the ISO/C standard for structures) | |
759 | ||
760 | ||
5ba9f198 MD |
761 | 7. Metadata |
762 | ||
3bf79539 MD |
763 | The meta-data is located in a stream named "metadata". It is made of "event |
764 | packets", which each start with an event packet header. The event type within | |
765 | the metadata stream have no event header nor event context. Each event only | |
5ba9f198 | 766 | contains a null-terminated "string" payload, which is a metadata description |
3bf79539 MD |
767 | entry. The events are packed one next to another. Each event packet start with |
768 | an event packet header, which contains, amongst other fields, the magic number | |
769 | and trace UUID. | |
5ba9f198 MD |
770 | |
771 | The metadata can be parsed by reading through the metadata strings, skipping | |
fcba70d4 MD |
772 | newlines and null-characters. Type names are made of a single identifier, and |
773 | can be surrounded by prefix/postfix. Text contained within "/*" and "*/", as | |
c6d7abc5 MD |
774 | well as within "//" and end of line, are treated as comments. Boolean values can |
775 | be represented as true, TRUE, or 1 for true, and false, FALSE, or 0 for false. | |
fcba70d4 MD |
776 | |
777 | The grammar representing the CTF metadata is presented in | |
778 | Appendix C. CTF Metadata Grammar. | |
5ba9f198 MD |
779 | |
780 | trace { | |
781 | major = value; /* Trace format version */ | |
782 | minor = value; | |
3bf79539 MD |
783 | uuid = value; /* Trace UUID */ |
784 | word_size = value; | |
785 | }; | |
5ba9f198 | 786 | |
3bf79539 MD |
787 | stream { |
788 | id = stream_id; | |
77a98c82 | 789 | /* Type 1 - Few event IDs; Type 2 - Many event IDs. See section 6.2. */ |
4fa992a5 MD |
790 | event.header := event_header_1 OR event_header_2; |
791 | event.context := struct { | |
77a98c82 | 792 | ... |
3bf79539 | 793 | }; |
4fa992a5 | 794 | packet.context := struct { |
77a98c82 | 795 | ... |
3bf79539 MD |
796 | }; |
797 | }; | |
5ba9f198 MD |
798 | |
799 | event { | |
3d13ef1a | 800 | name = event_name; |
3bf79539 MD |
801 | id = value; /* Numeric identifier within the stream */ |
802 | stream = stream_id; | |
4fa992a5 | 803 | context := struct { |
fcba70d4 MD |
804 | ... |
805 | }; | |
4fa992a5 | 806 | fields := struct { |
80fd2569 MD |
807 | ... |
808 | }; | |
3bf79539 | 809 | }; |
5ba9f198 MD |
810 | |
811 | /* More detail on types in section 4. Types */ | |
812 | ||
3d13ef1a MD |
813 | /* |
814 | * Named types: | |
815 | * | |
4fa992a5 | 816 | * Type declarations behave similarly to the C standard. |
3d13ef1a MD |
817 | */ |
818 | ||
819 | typedef aliased_type_prefix aliased_type new_type aliased_type_postfix; | |
2152348f | 820 | |
3d13ef1a | 821 | /* e.g.: typedef struct example new_type_name[10]; */ |
80fd2569 | 822 | |
4fa992a5 MD |
823 | /* |
824 | * typealias | |
825 | * | |
826 | * The "typealias" declaration can be used to give a name (including | |
827 | * prefix/postfix) to a type. | |
828 | */ | |
829 | ||
830 | typealias type_class { | |
80fd2569 | 831 | ... |
fcba70d4 | 832 | } : new_type_prefix new_type new_type_postfix; |
2152348f | 833 | |
3d13ef1a MD |
834 | /* |
835 | * e.g.: | |
4fa992a5 | 836 | * typealias integer { |
3d13ef1a MD |
837 | * size = 32; |
838 | * align = 32; | |
839 | * signed = false; | |
fcba70d4 | 840 | * } : struct page *; |
3d13ef1a | 841 | */ |
80fd2569 MD |
842 | |
843 | struct name { | |
3bf79539 MD |
844 | ... |
845 | }; | |
5ba9f198 | 846 | |
fcba70d4 MD |
847 | variant name { |
848 | ... | |
849 | }; | |
850 | ||
cfc73fdc | 851 | enum name <integer_type or size> { |
3bf79539 MD |
852 | ... |
853 | }; | |
854 | ||
2152348f | 855 | |
4fa992a5 MD |
856 | /* |
857 | * Unnamed types, contained within compound type fields, typedef or typealias. | |
858 | */ | |
2152348f | 859 | |
80fd2569 MD |
860 | struct { |
861 | ... | |
2152348f | 862 | } |
5ba9f198 | 863 | |
fcba70d4 MD |
864 | variant { |
865 | ... | |
866 | } | |
867 | ||
4767a9e7 | 868 | enum <integer_type or size> { |
80fd2569 | 869 | ... |
2152348f MD |
870 | } |
871 | ||
872 | typedef type new_type[length]; | |
3bf79539 | 873 | |
2152348f MD |
874 | struct { |
875 | type field_name[length]; | |
876 | } | |
877 | ||
878 | typedef type new_type[length_type]; | |
879 | ||
880 | struct { | |
881 | type field_name[length_type]; | |
882 | } | |
883 | ||
884 | integer { | |
80fd2569 | 885 | ... |
2152348f | 886 | } |
3bf79539 | 887 | |
2152348f | 888 | floating_point { |
80fd2569 | 889 | ... |
2152348f MD |
890 | } |
891 | ||
892 | struct { | |
893 | integer_type field_name:size; /* GNU/C bitfield */ | |
894 | } | |
895 | ||
896 | struct { | |
897 | string field_name; | |
898 | } | |
3bf79539 | 899 | |
fcba70d4 | 900 | |
3bf79539 | 901 | A. Helper macros |
5ba9f198 MD |
902 | |
903 | The two following macros keep track of the size of a GNU/C structure without | |
904 | padding at the end by placing HEADER_END as the last field. A one byte end field | |
905 | is used for C90 compatibility (C99 flexible arrays could be used here). Note | |
906 | that this does not affect the effective structure size, which should always be | |
907 | calculated with the header_sizeof() helper. | |
908 | ||
909 | #define HEADER_END char end_field | |
910 | #define header_sizeof(type) offsetof(typeof(type), end_field) | |
3bf79539 MD |
911 | |
912 | ||
913 | B. Stream Header Rationale | |
914 | ||
915 | An event stream is divided in contiguous event packets of variable size. These | |
916 | subdivisions allow the trace analyzer to perform a fast binary search by time | |
917 | within the stream (typically requiring to index only the event packet headers) | |
918 | without reading the whole stream. These subdivisions have a variable size to | |
919 | eliminate the need to transfer the event packet padding when partially filled | |
920 | event packets must be sent when streaming a trace for live viewing/analysis. | |
921 | An event packet can contain a certain amount of padding at the end. Dividing | |
922 | streams into event packets is also useful for network streaming over UDP and | |
923 | flight recorder mode tracing (a whole event packet can be swapped out of the | |
924 | buffer atomically for reading). | |
925 | ||
926 | The stream header is repeated at the beginning of each event packet to allow | |
927 | flexibility in terms of: | |
928 | ||
929 | - streaming support, | |
930 | - allowing arbitrary buffers to be discarded without making the trace | |
931 | unreadable, | |
932 | - allow UDP packet loss handling by either dealing with missing event packet | |
933 | or asking for re-transmission. | |
934 | - transparently support flight recorder mode, | |
935 | - transparently support crash dump. | |
936 | ||
937 | The event stream header will therefore be referred to as the "event packet | |
938 | header" throughout the rest of this document. | |
fcba70d4 MD |
939 | |
940 | C. CTF Metadata Grammar | |
941 | ||
4fa992a5 MD |
942 | /* |
943 | * Common Trace Format (CTF) Metadata Grammar. | |
944 | * | |
945 | * Inspired from the C99 grammar: | |
946 | * http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf (Annex A) | |
947 | * | |
948 | * Specialized for CTF needs by including only constant and declarations from | |
949 | * C99 (excluding function declarations), and by adding support for variants, | |
950 | * sequences and CTF-specific specifiers. | |
951 | */ | |
952 | ||
953 | 1) Lexical grammar | |
954 | ||
955 | 1.1) Lexical elements | |
956 | ||
957 | token: | |
958 | keyword | |
959 | identifier | |
960 | constant | |
961 | string-literal | |
962 | punctuator | |
963 | ||
964 | 1.2) Keywords | |
965 | ||
966 | keyword: is one of | |
967 | ||
968 | const | |
969 | char | |
970 | double | |
971 | enum | |
972 | event | |
973 | floating_point | |
974 | float | |
975 | integer | |
976 | int | |
977 | long | |
978 | short | |
979 | signed | |
980 | stream | |
981 | string | |
982 | struct | |
983 | trace | |
3e1e1a78 | 984 | typealias |
4fa992a5 MD |
985 | typedef |
986 | unsigned | |
987 | variant | |
988 | void | |
989 | _Bool | |
990 | _Complex | |
991 | _Imaginary | |
992 | ||
993 | ||
994 | 1.3) Identifiers | |
995 | ||
996 | identifier: | |
997 | identifier-nondigit | |
998 | identifier identifier-nondigit | |
999 | identifier digit | |
1000 | ||
1001 | identifier-nondigit: | |
1002 | nondigit | |
1003 | universal-character-name | |
1004 | any other implementation-defined characters | |
1005 | ||
1006 | nondigit: | |
1007 | _ | |
1008 | [a-zA-Z] /* regular expression */ | |
1009 | ||
1010 | digit: | |
1011 | [0-9] /* regular expression */ | |
1012 | ||
1013 | 1.4) Universal character names | |
1014 | ||
1015 | universal-character-name: | |
1016 | \u hex-quad | |
1017 | \U hex-quad hex-quad | |
1018 | ||
1019 | hex-quad: | |
1020 | hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit | |
1021 | ||
1022 | 1.5) Constants | |
1023 | ||
1024 | constant: | |
1025 | integer-constant | |
1026 | enumeration-constant | |
1027 | character-constant | |
1028 | ||
1029 | integer-constant: | |
1030 | decimal-constant integer-suffix-opt | |
1031 | octal-constant integer-suffix-opt | |
1032 | hexadecimal-constant integer-suffix-opt | |
1033 | ||
1034 | decimal-constant: | |
1035 | nonzero-digit | |
1036 | decimal-constant digit | |
1037 | ||
1038 | octal-constant: | |
1039 | 0 | |
1040 | octal-constant octal-digit | |
1041 | ||
1042 | hexadecimal-constant: | |
1043 | hexadecimal-prefix hexadecimal-digit | |
1044 | hexadecimal-constant hexadecimal-digit | |
1045 | ||
1046 | hexadecimal-prefix: | |
1047 | 0x | |
1048 | 0X | |
1049 | ||
1050 | nonzero-digit: | |
1051 | [1-9] | |
1052 | ||
1053 | integer-suffix: | |
1054 | unsigned-suffix long-suffix-opt | |
1055 | unsigned-suffix long-long-suffix | |
1056 | long-suffix unsigned-suffix-opt | |
1057 | long-long-suffix unsigned-suffix-opt | |
1058 | ||
1059 | unsigned-suffix: | |
1060 | u | |
1061 | U | |
1062 | ||
1063 | long-suffix: | |
1064 | l | |
1065 | L | |
1066 | ||
1067 | long-long-suffix: | |
1068 | ll | |
1069 | LL | |
1070 | ||
1071 | digit-sequence: | |
1072 | digit | |
1073 | digit-sequence digit | |
1074 | ||
1075 | hexadecimal-digit-sequence: | |
1076 | hexadecimal-digit | |
1077 | hexadecimal-digit-sequence hexadecimal-digit | |
1078 | ||
1079 | enumeration-constant: | |
1080 | identifier | |
1081 | string-literal | |
1082 | ||
1083 | character-constant: | |
1084 | ' c-char-sequence ' | |
1085 | L' c-char-sequence ' | |
1086 | ||
1087 | c-char-sequence: | |
1088 | c-char | |
1089 | c-char-sequence c-char | |
1090 | ||
1091 | c-char: | |
1092 | any member of source charset except single-quote ('), backslash | |
1093 | (\), or new-line character. | |
1094 | escape-sequence | |
1095 | ||
1096 | escape-sequence: | |
1097 | simple-escape-sequence | |
1098 | octal-escape-sequence | |
1099 | hexadecimal-escape-sequence | |
1100 | universal-character-name | |
1101 | ||
1102 | simple-escape-sequence: one of | |
1103 | \' \" \? \\ \a \b \f \n \r \t \v | |
1104 | ||
1105 | octal-escape-sequence: | |
1106 | \ octal-digit | |
1107 | \ octal-digit octal-digit | |
1108 | \ octal-digit octal-digit octal-digit | |
1109 | ||
1110 | hexadecimal-escape-sequence: | |
1111 | \x hexadecimal-digit | |
1112 | hexadecimal-escape-sequence hexadecimal-digit | |
1113 | ||
1114 | 1.6) String literals | |
1115 | ||
1116 | string-literal: | |
1117 | " s-char-sequence-opt " | |
1118 | L" s-char-sequence-opt " | |
1119 | ||
1120 | s-char-sequence: | |
1121 | s-char | |
1122 | s-char-sequence s-char | |
1123 | ||
1124 | s-char: | |
1125 | any member of source charset except double-quote ("), backslash | |
1126 | (\), or new-line character. | |
1127 | escape-sequence | |
1128 | ||
1129 | 1.7) Punctuators | |
1130 | ||
1131 | punctuator: one of | |
1132 | [ ] ( ) { } . -> * + - < > : ; ... = , | |
1133 | ||
1134 | ||
1135 | 2) Phrase structure grammar | |
1136 | ||
1137 | primary-expression: | |
1138 | identifier | |
1139 | constant | |
1140 | string-literal | |
1141 | ( unary-expression ) | |
1142 | ||
1143 | postfix-expression: | |
1144 | primary-expression | |
1145 | postfix-expression [ unary-expression ] | |
1146 | postfix-expression . identifier | |
1147 | postfix-expressoin -> identifier | |
1148 | ||
1149 | unary-expression: | |
1150 | postfix-expression | |
1151 | unary-operator postfix-expression | |
1152 | ||
1153 | unary-operator: one of | |
1154 | + - | |
1155 | ||
4fa992a5 MD |
1156 | assignment-operator: |
1157 | = | |
1158 | ||
1159 | constant-expression: | |
1160 | unary-expression | |
1161 | ||
1162 | constant-expression-range: | |
1163 | constant-expression ... constant-expression | |
1164 | ||
1165 | 2.2) Declarations: | |
1166 | ||
1167 | declaration: | |
1168 | declaration-specifiers declarator-list-opt ; | |
1169 | ctf-specifier ; | |
1170 | ||
1171 | declaration-specifiers: | |
1172 | storage-class-specifier declaration-specifiers-opt | |
1173 | type-specifier declaration-specifiers-opt | |
1174 | type-qualifier declaration-specifiers-opt | |
1175 | ||
1176 | declarator-list: | |
1177 | declarator | |
1178 | declarator-list , declarator | |
1179 | ||
1180 | storage-class-specifier: | |
1181 | typedef | |
1182 | ||
1183 | type-specifier: | |
1184 | void | |
1185 | char | |
1186 | short | |
1187 | int | |
1188 | long | |
1189 | float | |
1190 | double | |
1191 | signed | |
1192 | unsigned | |
1193 | _Bool | |
1194 | _Complex | |
9dfcfc0f MD |
1195 | struct-specifier |
1196 | variant-specifier | |
4fa992a5 MD |
1197 | enum-specifier |
1198 | typedef-name | |
1199 | ctf-type-specifier | |
1200 | ||
1201 | struct-specifier: | |
1202 | struct identifier-opt { struct-or-variant-declaration-list } | |
1203 | struct identifier | |
1204 | ||
1205 | struct-or-variant-declaration-list: | |
1206 | struct-or-variant-declaration | |
1207 | struct-or-variant-declaration-list struct-or-variant-declaration | |
1208 | ||
1209 | struct-or-variant-declaration: | |
1210 | specifier-qualifier-list struct-or-variant-declarator-list ; | |
1211 | ||
1212 | specifier-qualifier-list: | |
1213 | type-specifier specifier-qualifier-list-opt | |
1214 | type-qualifier specifier-qualifier-list-opt | |
1215 | ||
1216 | struct-or-variant-declarator-list: | |
1217 | struct-or-variant-declarator | |
1218 | struct-or-variant-declarator-list , struct-or-variant-declarator | |
1219 | ||
1220 | struct-or-variant-declarator: | |
1221 | declarator | |
1222 | declarator-opt : constant-expression | |
1223 | ||
1224 | variant-specifier: | |
1225 | variant identifier-opt variant-tag-opt { struct-or-variant-declaration-list } | |
1226 | variant identifier variant-tag | |
1227 | ||
1228 | variant-tag: | |
1229 | < identifier > | |
1230 | ||
1231 | enum-specifier: | |
1232 | enum identifier-opt { enumerator-list } | |
1233 | enum identifier-opt { enumerator-list , } | |
1234 | enum identifier | |
1235 | enum identifier-opt < type-specifier > { enumerator-list } | |
1236 | enum identifier-opt < type-specifier > { enumerator-list , } | |
1237 | enum identifier < type-specifier > | |
1238 | enum identifier-opt < integer-constant > { enumerator-list } | |
1239 | enum identifier-opt < integer-constant > { enumerator-list , } | |
1240 | enum identifier < integer-constant > | |
1241 | ||
1242 | enumerator-list: | |
1243 | enumerator | |
1244 | enumerator-list , enumerator | |
1245 | ||
1246 | enumerator: | |
1247 | enumeration-constant | |
1248 | enumeration-constant = constant-expression | |
1249 | enumeration-constant = constant-expression-range | |
1250 | ||
1251 | type-qualifier: | |
1252 | const | |
1253 | ||
1254 | declarator: | |
1255 | pointer-opt direct-declarator | |
1256 | ||
1257 | direct-declarator: | |
1258 | identifier | |
1259 | ( declarator ) | |
1260 | direct-declarator [ type-specifier ] | |
1261 | direct-declarator [ constant-expression ] | |
1262 | ||
1263 | pointer: | |
1264 | type-qualifier-list-opt | |
1265 | type-qualifier-list-opt pointer | |
1266 | ||
1267 | type-qualifier-list: | |
1268 | type-qualifier | |
1269 | type-qualifier-list type-qualifier | |
1270 | ||
4fa992a5 MD |
1271 | typedef-name: |
1272 | identifier | |
1273 | ||
1274 | 2.3) CTF-specific declarations | |
1275 | ||
1276 | ctf-specifier: | |
1277 | event { ctf-assignment-expression-list-opt } | |
1278 | stream { ctf-assignment-expression-list-opt } | |
1279 | trace { ctf-assignment-expression-list-opt } | |
1280 | ||
1281 | ctf-type-specifier: | |
1282 | floating_point { ctf-assignment-expression-list-opt } | |
1283 | integer { ctf-assignment-expression-list-opt } | |
1284 | string { ctf-assignment-expression-list-opt } | |
1285 | ||
1286 | ctf-assignment-expression-list: | |
1287 | ctf-assignment-expression | |
1288 | ctf-assignment-expression-list ; ctf-assignment-expression | |
1289 | ||
1290 | ctf-assignment-expression: | |
1291 | unary-expression assignment-operator unary-expression | |
1292 | unary-expression type-assignment-operator type-specifier |