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digitalmars.D.learn - Where is pragma Declaration in the grammar?

reply Stefan Koch <uplink.coder googlemail.com> writes:
Hi,

today I've been dusting my SDC fork and implemented a rudimentary 
version of pragma(msg).

I could pragmaStatement

as in void f()
{
    pragma(msg, typeof(f));
}

but not a declaration as in
pragma(msg, typeof(f))
without a function body.

there is a StaticAssert is in the grammar under declaration, 
pragma is not.

Maybe it's stated differently?

Any help is appreciated.

Cheers,

Stefan
Dec 04 2020
parent reply Paul Backus <snarwin gmail.com> writes:
On Saturday, 5 December 2020 at 00:57:04 UTC, Stefan Koch wrote:

 Hi,

 today I've been dusting my SDC fork and implemented a 
 rudimentary version of pragma(msg).

 I could pragmaStatement

 as in void f()
 {
    pragma(msg, typeof(f));
 }

 but not a declaration as in
 pragma(msg, typeof(f))
 without a function body.


They're under Attribute:

https://dlang.org/spec/grammar.html#Attribute

The syntax tree for `pragma(msg, typeof(f))` in a declaration 
context would be:

DeclDef
   AttributeSpecifier
     Attribute
       Pragma
         pragma(msg, typeof(f))
     DeclarationBlock
       DeclDef
         ;
Dec 04 2020
parent reply Stefan Koch <uplink.coder googlemail.com> writes:
On Saturday, 5 December 2020 at 02:59:58 UTC, Paul Backus wrote:

 On Saturday, 5 December 2020 at 00:57:04 UTC, Stefan Koch wrote:

 Hi,

 today I've been dusting my SDC fork and implemented a 
 rudimentary version of pragma(msg).

 I could pragmaStatement

 as in void f()
 {
    pragma(msg, typeof(f));
 }

 but not a declaration as in
 pragma(msg, typeof(f))
 without a function body.


 They're under Attribute:

 https://dlang.org/spec/grammar.html#Attribute

 The syntax tree for `pragma(msg, typeof(f))` in a declaration 
 context would be:

 DeclDef
   AttributeSpecifier
     Attribute
       Pragma
         pragma(msg, typeof(f))
     DeclarationBlock
       DeclDef
         ;


The Decldef is not optional.
This is for pragmas like pragma mangle that affect symbols.
Dec 04 2020
parent Paul Backus <snarwin gmail.com> writes:
On Saturday, 5 December 2020 at 03:55:52 UTC, Stefan Koch wrote:

 On Saturday, 5 December 2020 at 02:59:58 UTC, Paul Backus wrote:

 They're under Attribute:

 https://dlang.org/spec/grammar.html#Attribute

 The syntax tree for `pragma(msg, typeof(f))` in a declaration 
 context would be:

 DeclDef
   AttributeSpecifier
     Attribute
       Pragma
         pragma(msg, typeof(f))
     DeclarationBlock
       DeclDef
         ;


 The Decldef is not optional.
 This is for pragmas like pragma mangle that affect symbols.


That's what I thought at first too, but according to the official 
grammar, the DeclDef can be a single semicolon (i.e., empty):

https://dlang.org/spec/grammar.html#DeclDef
Dec 04 2020