update metadata packet header size vs content size

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

diff --git a/common-trace-format-proposal.txt b/common-trace-format-proposal.txt
index c25c94333616d8cfb877c01b9f83798faab33de6..2ae5ac282dee20c88e3428f5b03080e030ce2e09 100644 (file)
--- a/common-trace-format-proposal.txt
+++ b/common-trace-format-proposal.txt
@@ -193,6 +193,8 @@ TSDL meta-data representation:
     /* based used for pretty-printing output, default: decimal. */
     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
            OR octal OR oct OR o OR 8 OR binary OR b OR 2;
+    /* character encoding, default: none */
+    encoding = none or UTF8 or ASCII;
   }
 
 Example of type inheritance (creation of a uint32_t named type):
@@ -211,6 +213,17 @@ typealias integer {
   align = 1;
 } := int5_t;
 
+The character encoding field can be used to specify that the integer
+must be printed as a text character when read. e.g.:
+
+typealias integer {
+  size = 8;
+  align = 8;
+  signed = false;
+  encoding = UTF8;
+} := utf_char;
+
+
 4.1.6 GNU/C bitfields
 
 The GNU/C bitfields follow closely the integer representation, with a
@@ -220,7 +233,7 @@ defined by the size of the type "unit_type".
 
 TSDL meta-data representation:
 
-  unit_type name:size:
+  unit_type name:size;
 
 As an example, the following structure declared in C compiled by GCC:
 
@@ -649,7 +662,7 @@ the fields typically expected (although these fields are each optional):
 
 struct event_packet_header {
   uint32_t magic;
-  uint8_t  trace_uuid[16];
+  uint8_t  uuid[16];
   uint32_t stream_id;
 };
 
@@ -661,8 +674,8 @@ trace {
 If the magic number is not present, tools such as "file" will have no
 mean to discover the file type.
 
-If the trace_uuid is not present, no validation that the meta-data
-actually corresponds to the stream is performed.
+If the uuid is not present, no validation that the meta-data actually
+corresponds to the stream is performed.
 
 If the stream_id packet header field is missing, the trace can only
 contain a single stream. Its "id" field can be left out, and its events
@@ -763,7 +776,7 @@ struct event_header_1 {
       uint64_t timestamp;               /* 64-bit timestamps */
     } extended;
   } v;
-};
+} align(32);   /* or align(8) */
 
 
 6.1.2 Type 2 - Many event IDs
@@ -791,7 +804,7 @@ struct event_header_2 {
       uint64_t timestamp;               /* 64-bit timestamps */ 
     } extended;
   } v;
-};
+} align(16);   /* or align(8) */
 
 
 6.2 Event Context
@@ -887,15 +900,15 @@ endianness of the architecture by trying to read the CTF magic number
 and its counterpart in reversed endianness. The events within the
 meta-data stream have no event header nor event context. Each event only
 contains a "sequence" payload, which is a sequence of bits using the
-"trace.packet.header.content_size" field as a placeholder for its
-length. The formatting of this sequence of bits is a plain-text
-representation of the TSDL description. Each meta-data packet start with
-a special packet header, specific to the meta-data stream, which
-contains, exactly:
+"trace.packet.header.content_size" field as a placeholder for its length
+(the packet header size should be substracted). The formatting of this
+sequence of bits is a plain-text representation of the TSDL description.
+Each meta-data packet start with a special packet header, specific to
+the meta-data stream, which contains, exactly:
 
 struct metadata_packet_header {
   uint32_t magic;                      /* 0x75D11D57 */
-  uint8_t  trace_uuid[16];             /* Unique Universal Identifier */
+  uint8_t  uuid[16];                   /* Unique Universal Identifier */
   uint32_t checksum;                   /* 0 if unused */
   uint32_t content_size;               /* in bits */
   uint32_t packet_size;                        /* in bits */
@@ -1010,7 +1023,7 @@ trace {
   byte_order = be OR le;                       /* Endianness (required) */
   packet.header := struct {
     uint32_t magic;
-    uint8_t  trace_uuid[16];
+    uint8_t  uuid[16];
     uint32_t stream_id;
   };
 };
@@ -1454,9 +1467,9 @@ struct-or-variant-declaration-list:
 
 struct-or-variant-declaration:
        specifier-qualifier-list struct-or-variant-declarator-list ;
-       declaration-specifiers-opt 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 ;
+       declaration-specifiers-opt storage-class-specifier declaration-specifiers-opt declarator-list ;
+       typealias declaration-specifiers abstract-declarator-list type-assignment-operator declaration-specifiers abstract-declarator-list ;
+       typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list ;
 
 specifier-qualifier-list:
        type-specifier specifier-qualifier-list-opt
@@ -1490,8 +1503,8 @@ enumerator-list:
 
 enumerator:
        enumeration-constant
-       enumeration-constant = unary-expression
-       enumeration-constant = constant-expression-range
+       enumeration-constant assignment-operator unary-expression
+       enumeration-constant assignment-operator constant-expression-range
 
 type-qualifier:
        const
@@ -1530,21 +1543,22 @@ ctf-specifier:
        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 type-assignment-operator declaration-specifiers abstract-declarator-list
+       typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list
 
 ctf-type-specifier:
        floating_point { ctf-assignment-expression-list-opt }
        integer { ctf-assignment-expression-list-opt }
        string { ctf-assignment-expression-list-opt }
+       string
 
 ctf-assignment-expression-list:
-       ctf-assignment-expression
-       ctf-assignment-expression-list ; ctf-assignment-expression
+       ctf-assignment-expression ;
+       ctf-assignment-expression-list ctf-assignment-expression ;
 
 ctf-assignment-expression:
        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
+       declaration-specifiers-opt storage-class-specifier declaration-specifiers-opt declarator-list
+       typealias declaration-specifiers abstract-declarator-list type-assignment-operator declaration-specifiers abstract-declarator-list
+       typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list