We define "byte-packed" types as aligned on the byte size, namely 8-bit.
We define "bit-packed" types as following on the next bit, as defined by the
-"bitfields" section.
+"Integers" section.
All basic types, except bitfields, are either aligned on an architecture-defined
specific alignment or byte-packed, depending on the architecture preference.
Architectures providing fast unaligned write byte-packed basic types to save
space, aligning each type on byte boundaries (8-bit). Architectures with slow
unaligned writes align types on specific alignment values. If no specific
-alignment is declared for a type nor its parents, it is assumed to be bit-packed
-for bitfields and byte-packed for other types.
+alignment is declared for a type, it is assumed to be bit-packed for
+integers with size not multiple of 8 bits and for gcc bitfields. All
+other types are byte-packed.
Metadata attribute representation of a specific alignment:
size = 32;
signed = false;
align = 32;
-} : uint32_t;
+} := uint32_t;
Definition of a named 5-bit signed bitfield:
size = 5;
signed = true;
align = 1;
-} : int5_t;
+} := int5_t;
4.1.6 GNU/C bitfields
exp_dig = 8; /* sizeof(float) * CHAR_BIT - FLT_MANT_DIG */
mant_dig = 24; /* FLT_MANT_DIG */
byte_order = native;
-} : float;
+} := float;
TODO: define NaN, +inf, -inf behavior.
is in fact a range of size 1. This single-value range is supported without
repeating the start and end values with the value = string declaration.
-If a numeric value is encountered between < >, it represents the integer type
-size used to hold the enumeration, in bits.
-
-enum name <integer_type OR size> {
+enum name : integer_type {
somestring = start_value1 ... end_value1,
"other string" = start_value2 ... end_value2,
yet_another_string, /* will be assigned to end_value2 + 1 */
If the values are omitted, the enumeration starts at 0 and increment of 1 for
each entry:
-enum name <32> {
+enum name : unsigned int {
ZERO,
ONE,
TWO,
A nameless enumeration can be declared as a field type or as part of a typedef:
-enum <integer_type> {
+enum : integer_type {
+ ...
+}
+
+Enumerations omitting the container type ": integer_type" use the "int"
+type (for compatibility with C99). The "int" type must be previously
+declared. E.g.:
+
+typealias integer { size = 32; align = 32; signed = true } := int;
+
+enum {
...
}
};
struct {
- enum <integer_type or size> { sel1, sel2, sel3, ... } tag_field;
+ enum : integer_type { sel1, sel2, sel3, ... } tag_field;
...
variant name <tag_field> v;
}
metadata:
struct {
- enum <integer_type or size> { sel1, sel2, sel3, ... } tag_field;
+ enum : integer_type { sel1, sel2, sel3, ... } tag_field;
...
variant <tag_field> {
field_type sel1;
};
struct {
- enum <uint2_t> { a, b, c } choice;
+ enum : uint2_t { a, b, c } choice;
variant example <choice> v[unsigned int];
}
Example of an unnamed variant:
struct {
- enum <uint2_t> { a, b, c, d } choice;
+ enum : uint2_t { a, b, c, d } choice;
/* Unrelated fields can be added between the variant and its tag */
int32_t somevalue;
variant <choice> {
Example of an unnamed variant within an array:
struct {
- enum <uint2_t> { a, b, c } choice;
+ enum : uint2_t { a, b, c } choice;
variant <choice> {
uint32_t a;
uint64_t b;
the lexical scope of the type definition.
struct {
- enum <uint2_t> { a, b, c, d } x;
+ enum : uint2_t { a, b, c, d } x;
typedef variant <x> { /*
* "x" refers to the preceding "x" enumeration in the
} example_variant;
struct {
- enum <int> { x, y, z } x; /* This enumeration is not used by "v". */
+ enum : int { x, y, z } x; /* This enumeration is not used by "v". */
example_variant v; /*
- * "v" uses the "enum <uint2_t> { a, b, c, d }"
+ * "v" uses the "enum : uint2_t { a, b, c, d }"
* tag.
*/
} a[10];
typealias string {
encoding = UTF8 OR ASCII;
-} : name;
+} := name;
A nameless string type can be declared as a field type:
* id: range: 0 - 30.
* id 31 is reserved to indicate an extended header.
*/
- enum <uint5_t> { compact = 0 ... 30, extended = 31 } id;
+ enum : uint5_t { compact = 0 ... 30, extended = 31 } id;
variant <id> {
struct {
uint27_t timestamp;
* id: range: 0 - 65534.
* id 65535 is reserved to indicate an extended header.
*/
- enum <uint16_t> { compact = 0 ... 65534, extended = 65535 } id;
+ enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;
variant <id> {
struct {
uint32_t timestamp;
7. Metadata
-The meta-data is located in a stream named "metadata". It is made of "event
-packets", which each start with an event packet header. The event type within
-the metadata stream have no event header nor event context. Each event only
-contains a null-terminated "string" payload, which is a metadata description
-entry. The events are packed one next to another. Each event packet start with
-an event packet header, which contains, amongst other fields, the magic number
-and trace UUID. The trace UUID is represented as a string of hexadecimal digits
-and dashes "-".
-
-The metadata can be parsed by reading through the metadata strings, skipping
-newlines and null-characters. Type names are made of a single identifier, and
-can be surrounded by prefix/postfix. Text contained within "/*" and "*/", as
-well as within "//" and end of line, are treated as comments. Boolean values can
-be represented as true, TRUE, or 1 for true, and false, FALSE, or 0 for false.
+The meta-data is located in a stream identified by its name: "metadata".
+It is made of "event packets", which each start with an event packet
+header. The event type within the metadata stream have no event header
+nor event context. Each event only contains a null-terminated "string"
+payload, which is a metadata description entry. The events are packed
+one next to another. Each event packet start with an event packet
+header, which contains, amongst other fields, the magic number and trace
+UUID. In the event packet header, the trace UUID is represented as an
+array of bytes. Within the string-based metadata description, the trace
+UUID is represented as a string of hexadecimal digits and dashes "-".
+
+The metadata can be parsed by reading through the metadata strings,
+skipping null-characters. Type names are made of a single identifier,
+and can be surrounded by prefix/postfix. Text contained within "/*" and
+"*/", as well as within "//" and end of line, are treated as comments.
+Boolean values can be represented as true, TRUE, or 1 for true, and
+false, FALSE, or 0 for false.
7.1 Declaration vs Definition
the newly defined type name (for typedef), or the field name (for
declarations located within structure and variants). Array and sequence,
declared with square brackets ("[" "]"), are part of the declarator,
-similarly to C99. The enumeration type specifier and variant tag name
-(both specified with "<" ">") are part of the type specifier.
+similarly to C99. The enumeration base type is specified by
+": base_type", which is part of the type specifier. The variant tag
+name, specified between "<" ">", is also part of the type specifier.
A definition associates a type to a location in the event structure
hierarchy (see Section 6). This association is denoted by ":=", as shown
* Type declarations behave similarly to the C standard.
*/
-typedef aliased_type_prefix aliased_type new_type aliased_type_postfix;
+typedef aliased_type_specifiers new_type_declarators;
/* e.g.: typedef struct example new_type_name[10]; */
* typealias
*
* The "typealias" declaration can be used to give a name (including
- * prefix/postfix) to a type. It should also be used to map basic C types
- * (float, int, unsigned long, ...) to a CTF type. Typealias is a superset of
- * "typedef": it also allows assignment of a simple variable identifier to a
- * type.
+ * pointer declarator specifier) to a type. It should also be used to
+ * map basic C types (float, int, unsigned long, ...) to a CTF type.
+ * Typealias is a superset of "typedef": it also allows assignment of a
+ * simple variable identifier to a type.
*/
typealias type_class {
...
-} : new_type_prefix new_type new_type_postfix;
+} := type_specifiers type_declarator;
/*
* e.g.:
* size = 32;
* align = 32;
* signed = false;
- * } : struct page *;
+ * } := struct page *;
*
* typealias integer {
* size = 32;
* align = 32;
* signed = true;
- * } : int;
+ * } := int;
*/
struct name {
...
};
-enum name <integer_type or size> {
+enum name : integer_type {
...
};
...
}
-enum <integer_type or size> {
+enum : integer_type {
...
}
struct-or-variant-declaration:
specifier-qualifier-list struct-or-variant-declarator-list ;
declaration-specifiers storage-class-specifier declaration-specifiers declarator-list ;
- typealias declaration-specifiers abstract-declarator-list : declaration-specifiers abstract-declarator-list ;
- typealias declaration-specifiers abstract-declarator-list : declarator-list ;
+ typealias declaration-specifiers abstract-declarator-list := declaration-specifiers abstract-declarator-list ;
+ typealias declaration-specifiers abstract-declarator-list := declarator-list ;
specifier-qualifier-list:
type-specifier specifier-qualifier-list-opt
enum identifier-opt { enumerator-list }
enum identifier-opt { enumerator-list , }
enum identifier
- enum identifier-opt < declaration-specifiers > { enumerator-list }
- enum identifier-opt < declaration-specifiers > { enumerator-list , }
- enum identifier < declaration-specifiers >
- enum identifier-opt < integer-constant > { enumerator-list }
- enum identifier-opt < integer-constant > { enumerator-list , }
- enum identifier < integer-constant >
+ enum identifier-opt : declaration-specifiers { enumerator-list }
+ enum identifier-opt : declaration-specifiers { enumerator-list , }
enumerator-list:
enumerator
event { ctf-assignment-expression-list-opt }
stream { ctf-assignment-expression-list-opt }
trace { ctf-assignment-expression-list-opt }
- typealias declaration-specifiers abstract-declarator-list : declaration-specifiers abstract-declarator-list ;
- typealias declaration-specifiers abstract-declarator-list : declarator-list ;
+ typealias declaration-specifiers abstract-declarator-list := declaration-specifiers abstract-declarator-list ;
+ typealias declaration-specifiers abstract-declarator-list := declarator-list ;
ctf-type-specifier:
floating_point { ctf-assignment-expression-list-opt }
unary-expression assignment-operator unary-expression
unary-expression type-assignment-operator type-specifier
declaration-specifiers storage-class-specifier declaration-specifiers declarator-list
- typealias declaration-specifiers abstract-declarator-list : declaration-specifiers abstract-declarator-list
- typealias declaration-specifiers abstract-declarator-list : declarator-list
+ typealias declaration-specifiers abstract-declarator-list := declaration-specifiers abstract-declarator-list
+ typealias declaration-specifiers abstract-declarator-list := declarator-list
projects / ctf.git / blobdiff