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digitalmars.D - Any AST experts n da house?

reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Lucia is working on https://issues.dlang.org/show_bug.cgi?id=16683 which 
shows good promise in cleaning the cobwebs around Typeinfo. She looked 
into matters and figured she needs to have TypeidExp.semantic() return 
the lowered expression. In the code below

getFuncTemplateDecl(tidSymbol); // returns nil

and the compiler crashes when it hits this line.

//  extern (C++) final class TypeidExp : Expression   dmd-> expression.d

  override Expression semantic(Scope* sc)
     {
         auto tidIdentifierExp = new IdentifierExp(loc, new 
Identifier("__typeidImplT"));
         auto tidSymbol = new Dsymbol(new Identifier("__typeidImplT"));

         auto tidDeclaration = getFuncTemplateDecl(tidSymbol);
         auto tidExp = new TemplateExp(loc, tidDeclaration);
         auto callExp = new CallExp(loc, tidExp);

         return callExp;
     }

Any help would be appreciated.


Thanks,

Andrei
Nov 17 2016
next sibling parent reply Stefan Koch <uplink.coder googlemail.com> writes:
On Thursday, 17 November 2016 at 14:10:01 UTC, Andrei 
Alexandrescu wrote:

 Lucia is working on 
 https://issues.dlang.org/show_bug.cgi?id=16683 which shows good 
 promise in cleaning the cobwebs around Typeinfo. She looked 
 into matters and figured she needs to have TypeidExp.semantic() 
 return the lowered expression. In the code below

 getFuncTemplateDecl(tidSymbol); // returns nil

 and the compiler crashes when it hits this line.

 //  extern (C++) final class TypeidExp : Expression   dmd-> 
 expression.d

  override Expression semantic(Scope* sc)
     {
         auto tidIdentifierExp = new IdentifierExp(loc, new 
 Identifier("__typeidImplT"));
         auto tidSymbol = new Dsymbol(new 
 Identifier("__typeidImplT"));

         auto tidDeclaration = getFuncTemplateDecl(tidSymbol);
         auto tidExp = new TemplateExp(loc, tidDeclaration);
         auto callExp = new CallExp(loc, tidExp);

         return callExp;
     }

 Any help would be appreciated.


 Thanks,

 Andrei


I am looking into it.
Nov 17 2016
parent Stefan Koch <uplink.coder googlemail.com> writes:
On Thursday, 17 November 2016 at 14:11:50 UTC, Stefan Koch wrote:

 On Thursday, 17 November 2016 at 14:10:01 UTC, Andrei 
 Alexandrescu wrote:


          auto tidSymbol = new Dsymbol(new

 Identifier("__typeidImplT"));

 Andrei


 I am looking into it.


DSymbol is an abstract class.
It is not meant to be used.
Nov 17 2016
prev sibling parent Jacob Carlborg <doob me.com> writes:
On 2016-11-17 15:10, Andrei Alexandrescu wrote:

 Lucia is working on https://issues.dlang.org/show_bug.cgi?id=16683 which
 shows good promise in cleaning the cobwebs around Typeinfo. She looked
 into matters and figured she needs to have TypeidExp.semantic() return
 the lowered expression. In the code below

 getFuncTemplateDecl(tidSymbol); // returns nil

 and the compiler crashes when it hits this line.

 //  extern (C++) final class TypeidExp : Expression   dmd-> expression.d

  override Expression semantic(Scope* sc)
     {
         auto tidIdentifierExp = new IdentifierExp(loc, new
 Identifier("__typeidImplT"));
         auto tidSymbol = new Dsymbol(new Identifier("__typeidImplT"));

         auto tidDeclaration = getFuncTemplateDecl(tidSymbol);
         auto tidExp = new TemplateExp(loc, tidDeclaration);
         auto callExp = new CallExp(loc, tidExp);

         return callExp;
     }

 Any help would be appreciated.


Not related to the actual question. Instead of explicitly creating a new 
identifier, use Identifier.idPool [1], which will reuse any existing 
identifier or create a new one if necessary.

[1] https://github.com/dlang/dmd/blob/master/src/identifier.d#L141

-- 
/Jacob Carlborg
Nov 17 2016