RE: [cdt-core-dev] C++ Parser

[John Camelon <jcamelon@xxxxxxxxxx>]

I cannot find the UML diagrams that
I had drawn up for CDT 1.2 ... there is some reference documentation available
at http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/cdt-home/developer/docs.html?cvsroot=Tools_Project

Here's my 2 cents on the issue at hand
... since most of our current parser clients do not require a full AST
(as of yet), we should not create AST Nodes or offer ISourceElementRequestor
callbacks upon these constructs by default.   I would suggest creating
another ParserMode, and another Parser subclass (perhaps a subclass of
CompleteParser), and another IASTFactory implementation that would build
the AST for the parser.  

This is not a trivial task; I wish you
the best of luck ... feel free to email either this list or myself privately
if you have any more questions.  

Thanks,
JohnC
www.eclipse.org/cdt

cdt-core-dev-admin@xxxxxxxxxxx wrote on 07/08/2004
06:06:09 AM:

> John,
>  
> I understand.  So, if you have some documentation
you can share 
> (class hierarchy diagrams etc.) I’m willing to take a stab at it
now
> and send you the code as an input to your work.  This would greatly
> help me and at least you’ll be able to see how not to do it!  From
> my side the performance and scalability are not the issue, but the
> functionality.
>  
> As an aside, how is the keyword colouring achieved
in the editor?  
> Is this done through string matching in the renderer?
>  
> Jason
>  
> 
> From: cdt-core-dev-admin@xxxxxxxxxxx [mailto:cdt-core-dev-admin@xxxxxxxxxxx]
> On Behalf Of John Camelon
> Sent: Wednesday, July 07, 2004 5:23 PM
> To: cdt-core-dev@xxxxxxxxxxx
> Subject: Re: [cdt-core-dev] C++ Parser
>  
> 
> Our AST is incomplete when it comes to statements.  It is something
> we will need to address in the future once we get a bit more 
> performant and scalable.   
> 
> Thanks 
> JohnC 
> 
> cdt-core-dev-admin@xxxxxxxxxxx wrote on 07/07/2004 05:54:31 AM:
> 
> > I want to use the parser to give me details of where C/C++ 
> > statements are, however I have so far failed to penetrate the
AST 
> > with an instance of the ISourceElementRequestor (See code at
the 
> > end).  Here is an example of what I’d like as information,
take the 
> > following C code: 
> >   
> > 1: int main(int argc, char argv[]) 
> > 2: { 
> > 3:  if (argc == 0) { 
> > 4:    printf("You didn't pass in any arguments");
> > 5:    return -1; 
> > 6:  } 
> > 7:  else { 
> > 8:    printf("You passed in %d args\n",argc);
> > 9:    return 1; 
> > 10:  } 
> > 11:} 
> >   
> > I am particularly interested in understanding that the ‘If’
keyword 
> > is on line 3, the condition statement is also on line 3, the
‘else’ 
> > keyword is on line 7.  Then I need to know the details of
the ‘then’
> > code block and the ‘else’ code block. 
> >   
> > I traced through the parser code and it seems that it should
be 
> > possible to get this information, but it seems that the line
number 
> > is not stored, or it maybe stored if a new scope is generated
for 
> > the ‘if’.  For those not familiar with the code this token
reading 
> > etc. is all happening in the package cdt.internal.core.parser.
and 
> > cdt.internal.core.parser.ast. 
> >   
> > So right now my ISourceElementRequestor gets the codeBody call
back 
> > for the ‘then’ block and the ‘else’ block, but I don’t seem
to be 
> > able to determine  the details of the statements within
the code 
> > bodies, nor the location of syntactic keywords. 
> >   
> > Could someone please shed some light on this for me?  I
am assuming 
> > that this kind of thing is already done for the editor that 
> > highlights keywords in the source files, but I am not sure. 
> >   
> > Any insights will be very much appreciated.   
> >   
> > Jason 
> >   
> > PS: Below is the code I’m using. 
> >   
> > class CMySourceElementRequestor extends StructuralParseCallback
> > { 
> >     private ParserMode mode = ParserMode.COMPLETE_PARSE;
> >   
> >             private void addElement
(IASTDeclaration element){ 
> >                  
      if(inclusionLevel == 0){ 
> >                  
                  if( currentScope
instanceof ASTScope ) 
> >                  
                     
        ((ASTScope)
> > currentScope).addDeclaration(element); 
> >                  
                  else if(
currentScope instanceof
> > ASTLinkageSpecification ) 
> >                  
                     
        
> > ((ASTLinkageSpecification)currentScope).addDeclaration( element
); 
> >                  
      } 
> >             } 
> >             
> >             private void enterScope(IASTNode
node){ 
> >                  
      if(node instanceof IASTScope){ 
> >                  
                  if(node
instanceof ASTScope){ 
> >                  
                     
        ((ASTScope)node).
> > initDeclarations(); 
> >                  
                  } 
> >                  
                  pushScope((IASTScope)node);
> >                  
      } 
> >             } 
> >   
> >             private void exitScope(IASTNode
node){ 
> >                  
      if(node instanceof IASTScope){ 
> >                  
                  popScope();
> >                  
      } 
> >             } 
> >             
> >             private void pushScope(
IASTScope scope ){ 
> >                  
      scopeStack.addFirst( currentScope ); 
> >                  
      currentScope = scope; 
> >             } 
> >             
> >             private IASTScope popScope(){
> >                  
      IASTScope oldScope = currentScope; 
> >                  
      currentScope = (scopeStack.size() > 0 ) ? 
> > (IASTScope) scopeStack.removeFirst() : null; 
> >                  
      return oldScope; 
> >             } 
> >             
> >             public void enterFunctionBody(
IASTFunction function ) 
> >             { 
> >                  
      System.out.println("Enter function"); 
> >                  
      if(function.getOwnerTemplateDeclaration() == null)
> >                  
                  addElement(function);
> >                  
      else if(function.
> > getOwnerTemplateDeclaration() instanceof IASTTemplateDeclaration)
> >                  
                  
> > addElement((IASTTemplateDeclaration)function.getOwnerTemplateDeclaration());
> >             } 
> >             
> >             public void exitFunctionBody(
IASTFunction function ) 
> >             { 
> >                  
      System.out.println("Exit function"); 
> >                  
      function.setHasFunctionBody( true ); 
> >             } 
> >             
> >             public void enterCodeBlock(
IASTCodeScope scope ) 
> >             { 
> >                  
      System.out.println("Enter Code Block");
> >                  
      enterScope(scope); 
> >             } 
> >             
> >             public void exitCodeBlock(
IASTCodeScope scope ) 
> >             { 
> >                  
      System.out.println("Exit Code Block"); 
> >                  
      exitScope(scope); 
> >             } 
> >   
> >             public void enterCompilationUnit(
IASTCompilationUnit 
> > compilationUnit ) 
> >             { 
> >                  
      System.out.println("Enter Compilation Unit");
> >                  
      enterScope(compilationUnit); 
> >             } 
> >                  
      
> >             public void exitCompilationUnit(
IASTCompilationUnit 
> > compilationUnit ) 
> >             { 
> >                  
      System.out.println("Exit Compilation");
> >                  
      exitScope(compilationUnit); 
> >                  
      this.compUnit = compilationUnit; 
> >             } 
> >   
> >             /** 
> >              * @param finalPath
> >              * @return 
> >              */ 
> >             public CodeReader createReader(String
finalPath, 
> > Iterator workingCopies ) 
> >             { 
> >                  
      return InternalParserUtil.createFileReader( 
> > finalPath ); 
> >             } 
> >             /** 
> >              * The parser
asks the client if it wishes to time out 
> >              * in case it
is taking more than the expected time. 
> >              * @return 
> >              */ 
> >             public boolean parserTimeout()
> >             { 
> >                  
      return false; 
> >             } 
> > } 
> >   
> > /** 
> >  * @author jason 
> >  * 
> >  * TODO To change the template for this generated type comment
go to 
> >  * Window - Preferences - Java - Code Style - Code Templates
> >  */ 
> > public class Test { 
> >   
> >             public static void
main(String[] args) { 
> >                  
      IScanner myIScanner; 
> >                  
      IParser myIParser; 
> >                  
      CMySourceElementRequestor mySourceElementRequestor;
> >                  
      
> >                  
      try 
> >                  
      { 
> >                  
                  mySourceElementRequestor
= new 
> > CMySourceElementRequestor(); 
> >                  
                  myIScanner
= ParserFactory.
> > createScanner("c:\\temp\\test.c",new ScannerInfo(),ParserMode.
> > COMPLETE_PARSE,ParserLanguage.C, mySourceElementRequestor, null,null);
> >                  
                  myIParser
= ParserFactory.
> > createParser(myIScanner, mySourceElementRequestor, ParserMode.
> > COMPLETE_PARSE, ParserLanguage.C,null); 
> >                  
                  if (myIParser.parse()
== true) 
> >                  
                  { 
> >                  
                     
        System.out.
> > print("Parse successful"); 
> >                  
                  } 
> >                  
                  else 
> >                  
                  { 
> >                  
                     
        System.out.
> > print("Parse unsuccessful"); 
> >                  
                  } 
> >                  
      } 
> >                  
      catch (IOException e) 
> >                  
      { 
> >                  
                  return;
> >                  
      } 
> >             } 
> > }