Specify that trace readers (and not parser) should remove leading field underscores

[ctf.git] / common-trace-format-specification.txt

diff --git a/common-trace-format-specification.txt b/common-trace-format-specification.txt
index 545fbc7ebaa98ffeb602e481fcf038935c476ade..d306ffc06a5cab5734e3e42622c71dc37e5147df 100644 (file)
--- a/common-trace-format-specification.txt
+++ b/common-trace-format-specification.txt
@@ -420,7 +420,9 @@ The fields are placed in a sequence next to each other. They each
 possess a field name, which is a unique identifier within the structure.
 The identifier is not allowed to use any reserved keyword
 (see Section C.1.2). Replacing reserved keywords with
-underscore-prefixed field names is recommended.
+underscore-prefixed field names is recommended. Fields starting with an
+underscore should have their leading underscore removed by the CTF trace
+readers.
 
 A nameless structure can be declared as a field type or as part of a typedef:
 
@@ -461,7 +463,10 @@ the variant.
 Each variant type selector possess a field name, which is a unique
 identifier within the variant. The identifier is not allowed to use any
 reserved keyword (see Section C.1.2). Replacing reserved keywords with
-underscore-prefixed field names is recommended.
+underscore-prefixed field names is recommended. Fields starting with an
+underscore should have their leading underscore removed by the CTF trace
+readers.
+
 
 A named variant declaration followed by its definition within a structure
 declaration:
@@ -1085,7 +1090,9 @@ keywords "trace", "stream", and "event" are reserved, and thus
 not permitted as field names. It is recommended that field names
 clashing with CTF and C99 reserved keywords use an underscore prefix to
 eliminate the risk of generating a description containing an invalid
-field name.
+field name. Consequently, fields starting with an underscore should have
+their leading underscore removed by the CTF trace readers.
+
 
 The information available in the dynamic scopes can be thought of as the
 current tracing context. At trace production, information about the
@@ -1269,6 +1276,7 @@ clock {
         */
        offset_s = 1326476837;
        offset = 897235420;
+       absolute = FALSE;
 };
 
 The mandatory "name" field specifies the name of the clock identifier,
@@ -1284,7 +1292,11 @@ and "offset" fields indicate the offset from POSIX.1 Epoch, 1970-01-01
 00:00:00 +0000 (UTC), to the zero of value of the clock. The "offset_s"
 field is in seconds. The "offset" field is in (1/freq) units. If any of
 the "offset_s" or "offset" field is not present, it is assigned the 0
-value.
+value. The field "absolute" is TRUE if the clock is a global reference
+across different clock uuid (e.g. NTP time). Otherwise, "absolute" is
+FALSE, and the clock can be considered as synchronized only with other
+clocks that have the same uuid.
+
 
 Secondly, a reference to this clock should be added within an integer
 type: