Add enum {} default mapping to integer type

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

diff --git a/common-trace-format-proposal.txt b/common-trace-format-proposal.txt
index 445fe7ac733715fbce56c0c2185969759ecdc7be..d61b58c0fd73cc0856562db4b7c211e2ae338070 100644 (file)
--- a/common-trace-format-proposal.txt
+++ b/common-trace-format-proposal.txt
@@ -99,15 +99,16 @@ types, but must be derived into a type to be usable in an event field.
 
 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
 
 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
 
 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:
 
 
 Metadata attribute representation of a specific alignment:
 


@@ -185,7 +186,7 @@ typealias integer {
   size = 32;
   signed = false;
   align = 32;
   size = 32;
   signed = false;
   align = 32;

-} : uint32_t;
+} := uint32_t;

 
 Definition of a named 5-bit signed bitfield:
 
 
 Definition of a named 5-bit signed bitfield:
 


@@ -193,7 +194,7 @@ typealias integer {
   size = 5;
   signed = true;
   align = 1;
   size = 5;
   signed = true;
   align = 1;

-} : int5_t;
+} := int5_t;

 
 4.1.6 GNU/C bitfields
 
 
 4.1.6 GNU/C bitfields
 


@@ -252,7 +253,7 @@ typealias floating_point {
   exp_dig = 8;         /* sizeof(float) * CHAR_BIT - FLT_MANT_DIG */
   mant_dig = 24;       /* FLT_MANT_DIG */
   byte_order = native;
   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.
 
 
 TODO: define NaN, +inf, -inf behavior.
 


@@ -270,10 +271,7 @@ this format by having the same start_value and end_value for each element, which
 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.
 
 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 */
   somestring          = start_value1 ... end_value1,
   "other string"      = start_value2 ... end_value2,
   yet_another_string,  /* will be assigned to end_value2 + 1 */


@@ -284,7 +282,7 @@ enum name <integer_type OR size> {
 If the values are omitted, the enumeration starts at 0 and increment of 1 for
 each entry:
 
 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,
   ZERO,
   ONE,
   TWO,


@@ -296,7 +294,17 @@ Overlapping ranges within a single enumeration are implementation defined.
 
 A nameless enumeration can be declared as a field type or as part of a typedef:
 
 
 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 {

   ...
 }
 
   ...
 }
 


@@ -370,7 +378,7 @@ variant name {
 };
 
 struct {
 };
 
 struct {

-  enum <integer_type or size> { sel1, sel2, sel3, ... } tag_field;
+  enum : integer_type { sel1, sel2, sel3, ... } tag_field;

   ...
   variant name <tag_field> v;
 }
   ...
   variant name <tag_field> v;
 }


@@ -379,7 +387,7 @@ An unnamed variant definition within a structure is expressed by the following
 metadata:
 
 struct {
 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;
   ...
   variant <tag_field> {
     field_type sel1;


@@ -398,14 +406,14 @@ variant example {
 };
 
 struct {
 };
 
 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 {
   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> {
   /* Unrelated fields can be added between the variant and its tag */
   int32_t somevalue;
   variant <choice> {


@@ -422,7 +430,7 @@ struct {
 Example of an unnamed variant within an array:
 
 struct {
 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;
   variant <choice> {
     uint32_t a;
     uint64_t b;


@@ -437,7 +445,7 @@ type definition referring to the tag "x" uses the closest preceding field from
 the lexical scope of the type definition.
 
 struct {
 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
 
   typedef variant <x> {        /*
                         * "x" refers to the preceding "x" enumeration in the


@@ -449,9 +457,9 @@ struct {
   } example_variant;
 
   struct {
   } 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;                 /*
     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];
                                 * tag.
                                 */
   } a[10];


@@ -500,7 +508,7 @@ Metadata representation of a named string type:
 
 typealias string {
   encoding = UTF8 OR ASCII;
 
 typealias string {
   encoding = UTF8 OR ASCII;

-} : name;
+} := name;

 
 A nameless string type can be declared as a field type:
 
 
 A nameless string type can be declared as a field type:
 


@@ -653,7 +661,7 @@ struct event_header_1 {
    * id: range: 0 - 30.
    * id 31 is reserved to indicate an extended header.
    */
    * 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;
   variant <id> {
     struct {
       uint27_t timestamp;


@@ -681,7 +689,7 @@ struct event_header_2 {
    * id: range: 0 - 65534.
    * id 65535 is reserved to indicate an extended header.
    */
    * 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;
   variant <id> {
     struct {
       uint32_t timestamp;


@@ -790,8 +798,9 @@ variant field), a declaration is followed by a declarator, which specify
 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,
 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
 
 A definition associates a type to a location in the event structure
 hierarchy (see Section 6). This association is denoted by ":=", as shown


@@ -898,7 +907,7 @@ event {
  * Type declarations behave similarly to the C standard.
  */
 
  * 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]; */
 
 
 /* e.g.: typedef struct example new_type_name[10]; */
 


@@ -906,15 +915,15 @@ typedef aliased_type_prefix aliased_type new_type aliased_type_postfix;
  * typealias
  *
  * The "typealias" declaration can be used to give a name (including
  * 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 {
   ...
  */
 
 typealias type_class {
   ...

-} : new_type_prefix new_type new_type_postfix;
+} := type_specifiers type_declarator;

 
 /*
  * e.g.: 
 
 /*
  * e.g.: 


@@ -922,13 +931,13 @@ typealias type_class {
  *   size = 32;
  *   align = 32;
  *   signed = false;
  *   size = 32;
  *   align = 32;
  *   signed = false;

- * } : struct page *;
+ * } := struct page *;

  *
  * typealias integer {
  *  size = 32;
  *  align = 32;
  *  signed = true;
  *
  * typealias integer {
  *  size = 32;
  *  align = 32;
  *  signed = true;

- * } : int;
+ * } := int;

  */
 
 struct name {
  */
 
 struct name {


@@ -939,7 +948,7 @@ variant name {
   ...
 };
 
   ...
 };
 

-enum name <integer_type or size> {
+enum name : integer_type {

   ...
 };
 
   ...
 };
 


@@ -956,7 +965,7 @@ variant {
   ...
 }
 
   ...
 }
 

-enum <integer_type or size> {
+enum : integer_type {

   ...
 }
 
   ...
 }
 


@@ -1308,8 +1317,8 @@ struct-or-variant-declaration-list:
 struct-or-variant-declaration:
        specifier-qualifier-list struct-or-variant-declarator-list ;
        declaration-specifiers storage-class-specifier declaration-specifiers declarator-list ;
 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
 
 specifier-qualifier-list:
        type-specifier specifier-qualifier-list-opt


@@ -1334,12 +1343,8 @@ enum-specifier:
        enum identifier-opt { enumerator-list }
        enum identifier-opt { enumerator-list , }
        enum identifier
        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
 
 enumerator-list:
        enumerator


@@ -1389,8 +1394,8 @@ ctf-specifier:
        event { ctf-assignment-expression-list-opt }
        stream { ctf-assignment-expression-list-opt }
        trace { ctf-assignment-expression-list-opt }
        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 }
 
 ctf-type-specifier:
        floating_point { ctf-assignment-expression-list-opt }


@@ -1405,5 +1410,5 @@ 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
        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