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:
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,
};
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;
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
...
};
-enum name <integer_type or size> {
+enum name <integer_type> {
...
};
...
}
-enum <integer_type or size> {
+enum <integer_type> {
...
}
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 >
enumerator-list:
enumerator