Add scope semantic, add abstract declarations

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/common-trace-format-proposal.txt b/common-trace-format-proposal.txt
index 2a4dbfe25a40d8f206760054c80b196feaa4593b..d1136a2cd3a08d2de52819c3efced30b9778f252 100644 (file)
--- a/common-trace-format-proposal.txt
+++ b/common-trace-format-proposal.txt
@@ -607,10 +607,11 @@ The overall structure of an event is:
 
 6.1 Lexical Scope
 
 
 6.1 Lexical Scope
 

-The lexical scope of each structure (stream packet context, header, stream event
-context, event context and payload) is extended in the following way: lower
-levels (e.g. 3) can refer to fields defined in prior levels (e.g. 2 and 1). The
-field in the closest level has priority in case of field name conflict.
+For variant tag definition only, the lexical scope of each structure (stream
+packet context, header, stream event context, event context and payload) is
+extended in the following way: lower levels (e.g. 3) can refer to fields defined
+in prior levels (e.g. 2 and 1). The field in the closest level has priority in
+case of field name conflict.

 
 This allows, for instance, the event context to define a variant refering to the
 "id" field of the event header as selector.
 
 This allows, for instance, the event context to define a variant refering to the
 "id" field of the event header as selector.


@@ -774,6 +775,11 @@ 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.
 
 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.
 

+Each of "trace", "stream", "event", "struct" and "variant" have their own
+nestable declaration scope, within which types can be declared using "typedef"
+and "typealias". An innermost declaration scope can refer to type declared
+within its container lexical scope prior to the innermost declaration scope.
+

 The grammar representing the CTF metadata is presented in
 Appendix C. CTF Metadata Grammar.
 
 The grammar representing the CTF metadata is presented in
 Appendix C. CTF Metadata Grammar.
 


@@ -1177,6 +1183,10 @@ declarator-list:
        declarator
        declarator-list , declarator
 
        declarator
        declarator-list , declarator
 

+abstract-declarator-list:
+       abstract-declarator
+       abstract-declarator-list , abstract-declarator
+

 storage-class-specifier:
        typedef
 
 storage-class-specifier:
        typedef
 


@@ -1209,7 +1219,8 @@ 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 declaration-specifiers declarator-list : declaration-specifiers 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


@@ -1262,6 +1273,16 @@ direct-declarator:
        direct-declarator [ type-specifier ]
        direct-declarator [ constant-expression ]
 
        direct-declarator [ type-specifier ]
        direct-declarator [ constant-expression ]
 

+abstract-declarator:
+       pointer-opt direct-abstract-declarator
+
+direct-abstract-declarator:
+       identifier-opt
+       ( abstract-declarator )
+       direct-abstract-declarator [ type-specifier ]
+       direct-abstract-declarator [ constant-expression ]
+       direct-abstract-declarator [ ]
+

 pointer:
        * type-qualifier-list-opt
        * type-qualifier-list-opt pointer
 pointer:
        * type-qualifier-list-opt
        * type-qualifier-list-opt pointer


@@ -1279,7 +1300,8 @@ 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 declaration-specifiers declarator-list : declaration-specifiers 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 }


@@ -1294,4 +1316,5 @@ 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 declaration-specifiers declarator-list : declaration-specifiers declarator-list
+       typealias declaration-specifiers abstract-declarator-list : declaration-specifiers abstract-declarator-list
+       typealias declaration-specifiers abstract-declarator-list : declarator-list